122
NATIONAL VEGETATION CLASSIFICATION field guide to mires and heaths
NATIONAL VEGETATION CLASSIFICATION
field guide tomires and heaths
National Vegetation Classification:Field guide to mires and heaths
Cover photograph:Studland Heath National Nature Reserve, Dorset.© English Nature
National Vegetation Classification:Field guide to mires and heaths
T. Elkington, N. Dayton, D.L. Jackson and I.M. Strachan
Joint Nature Conservation CommitteeMonkstone HouseCity RoadPeterboroughPE1 1JYUK
ISBN 1 86107 526 X
© JNCC 2001
5
1. Introduction 7National Vegetation Classification 7Mires and heaths: scope of this guide 7Using this guide 7References 8
2. Dendrogram keys to mire communities 9
3. Mire community descriptions and sub-community keys 19M1 Sphagnum auriculatum bog pool community 19M2 Sphagnum cuspidatum/recurvum bog pool community 20M3 Eriophorum angustifolium bog pool community 21M4 Carex rostrata – Sphagnum recurvum mire 22M5 Carex rostrata – Sphagnum squarrosum mire 23M6 Carex echinata – Sphagnum recurvum/auriculatum mire 24M7 Carex curta – Sphagnum russowii mire 26M8 Carex rostrata – Sphagnum warnstorfii mire 27M9 Carex rostrata – Calliergon cuspidatum/giganteum mire 28M10 Carex dioica – Pinguicula vulgaris mire 30M11 Carex demissa – Saxifraga aizoides mire 32M12 Carex saxatilis mire 33M13 Schoenus nigricans – Juncus subnodulosus mire 34M14 Schoenus nigricans – Narthecium ossifragum mire 34M15 Scirpus cespitosus – Erica tetralix wet heath 36M16 Erica tetralix – Sphagnum compactum wet heath 38M17 Scirpus cespitosus – Eriophorum vaginatum blanket mire 40M18 Erica tetralix – Sphagnum papillosum raised & blanket mire 42M19 Calluna vulgaris – Eriophorum vaginatum blanket mire 44M20 Eriophorum vaginatum blanket & raised mire 46M21 Narthecium ossifragum – Sphagnum papillosum valley mire 47M22 Juncus subnodulosus – Cirsium palustre fen-meadow 48M23 Juncus effusus/acutiflorus – Galium palustre rush-pasture 50M24 Molinia caerulea – Cirsium dissectum fen-meadow 52M25 Molinia caerulea – Potentilla erecta mire 54M26 Molinia caerulea – Crepis paludosa mire 56M27 Filipendula ulmaria – Angelica sylvestris mire 58M28 Iris pseudacorus – Filipendula ulmaria mire 60M29 Hypericum elodes – Potamogeton polygonifolius soakway 62M30 Related vegetation of seasonally inundated habitats 62M31 Anthelia julacea – Sphagnum auriculatum spring 63M32 Philonotis fontana – Saxifraga stellaris spring 64
Contents
6
M33 Pohlia wahlenbergii var. glacialis spring 66M34 Carex demissa – Koenigia islandica flush 66M35 Ranunculus omiophyllus – Montia fontana rill 67M36 Lowland springs and streambanks of shaded situations 67M37 Cratoneuron commutatum – Festuca rubra spring 68M38 Cratoneuron commutatum – Carex nigra spring 69
4. Dendrogram keys to heath communities 70
5. Heath community descriptions and sub-community keys 76H1 Calluna vulgaris – Festuca ovina heath 76H2 Calluna vulgaris – Ulex minor heath 78H3 Ulex minor – Agrostis curtisii heath 80H4 Ulex gallii – Agrostis curtisii heath 82H5 Erica vagans – Schoenus nigricans heath 84H6 Erica vagans – Ulex europaeus heath 86H7 Calluna vulgaris – Scilla verna heath 88H8 Calluna vulgaris – Ulex gallii heath 90H9 Calluna vulgaris – Deschampsia flexuosa heath 92H10 Calluna vulgaris – Erica cinerea heath 94H11 Calluna vulgaris – Carex arenaria heath 96H12 Calluna vulgaris – Vaccinium myrtillus heath 98H13 Calluna vulgaris – Cladonia arbuscula heath 100H14 Calluna vulgaris – Racomitrium lanuginosum heath 102H15 Calluna vulgaris – Juniperus communis ssp. nana heath 104H16 Calluna vulgaris – Arctostaphylos uva-ursi heath 104H17 Calluna vulgaris – Arctostaphylos alpinus heath 106H18 Vaccinium myrtillus – Deschampsia flexuosa heath 108H19 Vaccinium myrtillus – Cladonia arbuscula heath 110H20 Vaccinium myrtillus – Racomitrium lanuginosum heath 112H21 Calluna vulgaris – Vaccinium myrtillus – Sphagnum
capillifolium heath 114H22 Vaccinium myrtillus – Rubus chamaemorus heath 116
National Vegetation Classification
7
1 Introduction
Since its development in the 1980s, the NationalVegetation Classification (NVC) has become thestandard classification used for describing vegeta-tion in Britain. Whereas many other classificationsare restricted to particular types of vegetation, theNVC aims to describe all the vegetation of GreatBritain. This means that it is possible to analyse,and map, a complex site, composed of severalhabitat types (e.g. woodland, scrub, heathland andbog) using the same classification system.
The NVC is a ‘phytosociological’ classification,classifying vegetation solely on the basis of theplant species of which it is composed. The result-ing communities can usually be correlated to otherfactors, such as geology and soils, climate, waterchemistry and management; but the plant speciesalone are used to assign the vegetation to a community.
The NVC breaks down each broad vegetationtype (e.g. heath, mire, woodland) into communities,designated by a number and name (e.g. H4 Ulex gal-lii – Agrostis curtisii heath, M10 Carex dioica –Pinguicula vulgaris mire, W4 Betula pubescens –Molinia caerulea woodland). Many (but not all) ofthese communities contain two or more sub-com-munities, designated by a letter (e.g. H4b Ulex gal-lii – Agrostis curtisii heath, Festuca ovina sub-com-munity). Sub-communities in a few cases are fur-ther divided into variants (e.g. M10bi and ii).
The second volume of British Plant Communitieswas published in 1991 (Rodwell 1991a). It providesa detailed account of 38 mire communities and 22heath communities, giving information on theircomposition, structure and distribution, theiraffinities to other types of vegetation, both inBritain and on the Continent, and the relation ofthe communities described within the NVC tothose previously described by other authors. Thescope of this field guide is identical to that ofVolume 2.
A number of vegetation types which might alsobe considered as ‘mires’ or ‘heaths’ are describedin other volumes of British Plant Communities,and so are not included here. Aquatic, swamp andtall-herb fen communities can be found in Volume4 (Rodwell 1995), whilst inundation communities,
Mires and heaths: scope of this guide
dune slack communities and Epilobium hirsutumstands are described in Volume 5 (Rodwell 2000).‘Grass heaths’, Dryas heaths and related lichenand bryophyte dominated vegetation are includedin Volume 3 (Rodwell 1992), as are certain wetgrasslands. Volume 1 (Rodwell 1991b) encompasseswet woodland and scrub vegetation. Companionguides to volumes 1 and 3 have also been pub-lished by JNCC (Hall et al. 2001; Cooper 1997).
Users of this guide should also note that most‘wet heath’ vegetation is described in the NVCwith the mires rather than the heaths (as M15Scirpus cespitosus – Erica tetralix wet heath andM16 Erica tetralix – Sphagnum compactum wetheath), because of its floristic affinities. Helpfulinsight into the floristic relationships of NVCtypes can be gained from the PhytosociologicalConspectus in Volume 5 of British PlantCommunities. This places all NVC communitieswithin a hierarchical framework of European vegetation.
Various gaps in coverage of the NVC have beenidentified at community and sub-community levelsubsequent to the publication of British PlantCommunities. These include several mire andheath types, as outlined in JNCC Report No. 302Review of coverage of the National VegetationClassification (Rodwell et al. 2000). No attempthas been made to incorporate these here, pendingfurther analysis and formal description.
The summary descriptions provided here arederived directly from the full accounts preparedby John Rodwell, but are in no way a substitute forthem. Rather they are intended as an aide-mem-oire to assist surveyors in the field or for anyoneelse wishing to familiarise themselves with theoverall scheme of classification for mires andheaths. Anyone who uses this book should alwayscheck their results against the frequency tablesand full descriptions for each community inVolume 2 of British Plant Communities. Thedescriptions are not intended to take account ofthe results of recent survey work undertaken bythe three country agencies (Countryside Councilfor Wales, English Nature, Scottish NaturalHeritage) which may help circumscribe some ofthe communities more tightly and improve ourunderstanding of community distributions.
Using this guide
8
A series of dendrograms have been produced toshow the broad floristic relationships between themain communities and between the sub-commu-nities for each community where these exist.These dendrograms are only intended as guidesand should not be followed slavishly. Details ofvariants, if indicated, can be found in Volume 2 ofBritish Plant Communities.
The amount of any particular species isreferred to both in terms of its frequency andabundance. ‘Frequency’ refers to how often a plantis found in moving from one sample or vegetationto the next, irrespective of how much of thatspecies is present in each sample. This is sum-marised in the published tables as classes denotedby the Roman numerals I to V: 1-20% frequency(that is, up to one sample in five) = I, 21-40% = II,41-60% = III, 61-80% = IV, and 81-100% = V. Thesummary descriptions follow the usual conven-tion of referring to species of frequency classes IVand V in a particular community as its constants,with those species of class III as common or fre-quent, of class II as occasional and of class I asscarce or rare. The term ‘abundance’, on the otherhand, is used to describe how much of a plant ispresent in a sample, irrespective of how frequentor rare it is among the samples. It is summarisedin the published tables as bracketed numbers forthe Domin ranges, and is referred to in the texthere, as in the published descriptions, using suchterms as dominant, abundant, frequent and sparse.
The nomenclature for plant species used inBritish Plant Communities has been followed inthis publication for consistency. Botanists morefamiliar with Stace’s New flora of the British Isles(Stace 1997) may not recognise names such as(Stace equivalent in brackets): Scirpus cespitosus(Trichophorum cespitosum), Carex demissa (C. viridula ssp. oedocarpa), C. lepidocarpa (C. viridula ssp. brachyrrhyncha) and Silene vul-garis maritima (S. uniflora). Amongst cryptogams,the common lichen of heaths and bogs referred tohere as Cladonia impexa is now generally knownas C. portentosa.
References
Cooper, E A (1997) Summary descriptions of Nat-ional Vegetation Classification grassland andmontane communities. Joint Nature Con-servation Committee, Peterborough (UK NatureConservation No. 14).
Hall, J E, Kirby, K J and Whitbread, A M (2001)National Vegetation Classification: field guideto woodland. Joint Nature Conservation Com-mittee, Peterborough.
Rodwell, J S, (ed) (1991a) British Plant Commun-ities. Volume 2. Mires and heaths. CambridgeUniversity Press, Cambridge.
Rodwell, J S, (ed) (1991b) British Plant Commun-ities. Volume 1. Woodlands and scrub. CambridgeUniversity Press, Cambridge.
Rodwell, J S, (ed) (1992) British Plant Commun-ities. Volume 3. Grasslands and montane com-munities. Cambridge University Press, Cambridge.
Rodwell, J S, (ed) (1995) British Plant Commun-ities. Volume 4. Aquatic communities, swampsand tall-herb fens. Cambridge University Press,Cambridge.
Rodwell, J S, (ed) (2000) British Plant Commun-ities. Volume 5. Maritime communities andvegetation of open habitats. Cambridge University Press, Cambridge.
Rodwell, J S, Dring, J C, Averis, A B G, Proctor, MC F, Malloch, A J C, Schaminée, J N J andDargie, T C D (2000) Review of coverage of theNational Vegetation Classification. JNCC ReportNo. 302.
Stace, C (1997) New flora of the British Isles. 2nded. Cambridge University Press, Cambridge.
9
2 Dendrogram keys to mire communities
A K
ey t
o m
ires
1. S
ph
agn
um
spp
.co
nst
ant
or v
ery
freq
uen
t in
th
e ve
geta
tion
, eit
her
co
nti
nu
ous
or p
atch
y.
2a. S
ub-s
hrub
sn
ot c
onst
ant;
thou
gh C
allu
na
vulg
aris
and
/or
Eri
ca t
etra
lix
may
be
pre
sen
t at
low
abu
nd
ance
.
3. D
omin
ated
by
sed
ges
Eri
oph
oru
m,
Car
exsp
p.,
orta
ll r
ush
esJu
ncu
ssp
p.
3a. S
edge
s m
aybe
pre
sen
t bu
tar
e su
bord
inat
eto
bry
oph
ytes
or
to o
ther
vas
cula
rsp
ecie
s.
4. V
eget
atio
n
dom
inat
ed b
yE
riop
hor
um
angu
stif
oliu
man
d/o
r E
.va
gin
atu
m.
4a. V
ege-
tati
on d
omi-
nat
ed b
yot
her
sed
ges
or t
all
rush
es.
6. S
emi-
aqu
atic
ril
lsan
d f
lush
es
dom
inat
ed b
yP
otam
oget
onp
olyg
onif
oliu
san
d/o
rM
onti
afo
nta
na.
6a. O
pen
bryo
ph
yte
mat
s ar
oun
dsp
rin
gs.
Sp
hag
nu
mau
ricu
latu
mca
n b
e co
nst
ant.
5. M
ossy
ca
rpet
d
omin
ated
byse
mi-
aqu
atic
Sp
hag
nu
msp
p.,
incl
ud
-in
g S
. cu
spi-
dat
um
wit
hva
scu
lar
spec
ies
typ
ical
lysp
arse
. B
og p
ools
.
See
Fig
1.
See
Fig
2.
See
Fig
3.
See
Fig
4.
See
Fig
5.
See
Fig
6.
7. S
pri
ng
or f
lush
veg
eta-
tion
; an
op
en b
ryop
hyt
e-ri
ch m
at i
n w
hic
h a
ny
of:
Cra
ton
euro
n c
omm
utat
um,
Ph
ilon
otis
fon
tan
a,A
nth
elia
jula
cea,
Poh
lia
wah
len
berg
iior
Koe
nig
iais
lan
dic
aca
n b
e pr
omin
ent.
1a. S
ph
agn
um
spp
. not
con
stan
t in
th
e ve
geta
tion
.O
ccas
ion
al s
mal
l p
atch
esm
ay b
e p
rese
nt
but
thes
e ar
e n
ever
pro
min
ent.
7a. M
ore
bulk
yve
geta
tion
in
wh
ich
sed
ges,
rush
es, g
rass
esor
tal
l h
erbs
are
pro
min
ent.
8. V
eget
atio
nd
omin
ated
by
sed
ges,
Car
exor
Eri
oph
oru
msp
p.,
eith
er i
nlo
w, o
pen
mat
sor
tal
ler,
mor
ed
ense
mir
es.
9. M
olin
ia c
aeru
lea
con
stan
t an
d u
sual
lyst
ruct
ura
lly
imp
orta
nt
in t
he
vege
tati
on; w
ith
or w
ith
out
Sch
oen
us
nig
rica
ns.
9a. T
all
rush
es,
Junc
ussp
p.,
and
/or
tall
fen
her
bs d
omin
ant.
Mol
inia
cae
rule
ara
re b
ut
may
be
loca
lly
abu
nd
ant
in w
este
rnm
ires
.
See
Fig
6.
See
Fig
7.
See
Fig
8.
See
Fig
9.
2. C
allu
na
vulg
aris
and
/or
Eri
ca
tetr
alix
con
stan
t.U
sual
lyqu
ite
exte
n-
sive
mir
esov
er p
eat.
5a. O
pen
spri
ngs
or
rill
sw
ith
con
stan
t,bu
t p
atch
yS
ph
agn
um
auri
cula
tum
.
8a. S
edge
s m
aybe
fre
quen
t in
th
esw
ard
bu
t n
otd
omin
ant
and
nev
er s
tru
ctu
rall
yim
por
tan
t.
10
2a. Scirpus cespitosusnot constant and rarelyprominent, though canbe frequent in patches.Molinia caerulea generally absent (canform mosaics with tus-socky Eriophorum vagi-natum in degraded formsof M19.)
3. Sphagnum spp.prominent, especially S. papillosum, S. capilli-folium and S. tenellum,often S. magellanicum.Associates include atleast some of Vacciniumoxycoccos, Droserarotundifolia andOdontoschisma sphagni.
3a. Sphagnum spp. patchy,though S. capillifoliumconstant. S. tenellum,S. magellanicum andOdontoschisma sphagni generally absent or very rare.
4a. Vegetation dominatedby tussocks of Eriophorumvaginatum with Callunavulgaris and Sphagnum spp. at best infrequent and patchy. Mounds ofEmpetrum nigrum and/orVaccinium myrtillus withconstant Eriophorum angustifolium andDeschampsia flexuosa.
M20b Eriophorum vaginatum blanket andraised mire, Calluna vulgaris – Cladonia spp. sub-community
4. Calluna vulgaris andEriophorum vaginatum formthe bulk of the vegetation, E. vaginatum usually tus-socky, with Sphagnum capil-lifolium, E. angustifoliumand pleurocarpous mosses:Pleurozium schreberi,Hylocomium splendens and Hypnum jutlandicum.
M17 Scirpus cespitosus –Eriophorum vaginatumblanket mire
M18 Erica tetralix –Sphagnum papillosumraised and blanket mire
M19 Calluna vulgaris –Eriophorum vaginatum blanket mire
The Eriophorum mire is apparently bioticallyderived from M19 blanketbog or M18 raised mire;the degree of floristicimpoverishment depend-ing on the intensity andduration of destructivemanagement practice.There is therefore a con-tinuous gradation betweenricher and poorer stands.In the wet north-westsome Sphagnum spp.can persist even in highly degraded stands,especially S. recurvum which is relatively toler-ant to some disturbance.
1a. See next page
2. Molinia caeruleaand/or Scirpus cespitosusconstant with at leastsome: Nartheciumossifragum, Eriophorumangustifolium, Potentillaerecta, Sphagnum papillosum andS. capillifolium.
1. Eriophorum vaginatum(either as prominent tussocks or sparse fronds) and/orSphagnum papillosum and/or S. magellanicum constant. Deep peat > 1 m. Blanket and raised mires.
Burning can increase the proportion of Calluna vulgaris or Deschampsia flexuosa and Vaccinium myrtillus. Grazing usually decreases the abundance ofC. vulgaris, ultimately to itsdisappearance, especially ifcombined with large-scaleburns. Such disturbance canshift the floristics of this community towards theimpoverished M20 mire.Lower altitude stands (<400 m) to the west usuallyinclude constant Erica tetral-ix which is replaced in high-er and more eastern standsby Empetrum nigrum and Rubus chamaemorus.
Mires Figure 1
Fig 1. Key to vegetation with constant Sphagnum spp. and constant ericoid sub-shrubs
11
6a. Nartheciumossifragum present atlow frequency. Ericoidsub-shrubs and at leastone of Scirpus cespitosus,Molinia caerulea andEriophorum angustifoliummake up the bulk of thevegetation over patchysphagna, S. capillifoliumor S. compactum. Wet heaths.
7. Erica tetralix usuallythe most prominent sub-shrub. Sphagnum layer dominated by S. compactum and S. tenellum. Moliniacaerulea usually domi-nant amongst the vascu-lar monocot associates.
May be confused with theflushed wet heath, M15a;however the sedges Carex panicea, C. echinataare constant in the latterand Myrica gale is morefrequent. Pinguicula vul-garis is common in M15abut is replaced in theM21 community by lessfrequent P. lusitanica.
5a. Erica tetralix constant.Calluna vulgaris absent orpresent at low frequency inthe vegetation.
6. Narthecium ossifragumconstant and abundantwith Drosera rotundifolia,Eriophorum angustifolium,Sphagnum papillosum,plus S. auriculatum and/or S. recurvum. Schoenusnigricans absent or very rare.
5. Calluna vulgaris and Ericatetralix both prominent withEriophorum angustifolium and Molinia caerulea constant.
From previous page: 1a. Both Eriophorum vaginatum and Sphagnum papillosum generally absent, though may be patchily present at low frequency in the wetter sub-communities of the M15 Erica – Scirpus mire.
8. Schoenusnigricans constant withprominentNartheciumossifragumand Sphagnumsubnitens.
M21 Nartheciumossifragum – Sphagnumpapillosum valley mire
Wet heath primarily ofthe south and east ofBritain, this communityprovides the major locusfor Scirpus cespitosus and Eriophorum vaginatum (though rare)in this part of the country.
M16 Erica tetralix –Sphagnum compactum wet heath
This is a very variablevegetation type and, ofthe major components,any can be dominant withup to two of the othersmissing. A communityprimarily of north-westBritain, it includes mostof the heather-dominated vegetation intermediate incharacter between the dryheath and blanket miretypes. Where heavilygrazed and/or burnt, theericoids can become verysparse and these standsare often transitional tothe Molinia-dominated community M25, or drier stands to the Juncussquarrosus grassland U6.
M15 Scirpus cespitosus –Erica tetralix wet heath
M14 Schoenusnigricans –Nartheciumossifragummire
7a. Calluna vulgaris usu-ally the most prominentsub-shrub except wheregrazing pressure hasfavoured the expansion of E. tetralix. Sphagnumspp. dominated by S. capillifolium and S. subnitens with occasional S. papillosumin the wetter sub-communities.
8a. Moliniacaerulea dominant, denseand tussocky.Sparse Ericatetralix andPotentilla erecta constant.Sphagnumpalustre and S. recurvum canbe prominent in wet north-western stands.
M25a Moliniacaerulea –Potentilla erecta mire,Erica tetralixsub-community
Burning andgrazing of M15wet heath canfavour anincrease inMolinia whichshifts the vegetationtowards that ofthe Erica tetralixsub-communityof M25. Thesimilaritiesbetween M25aand Molinia- rich M15 showthe transitionbetween thesetwo communitiesthrough distur-bance.
12
M3 Eriophorum angustifolium bog pool
1a. Vegetation dominated byEriophorum vaginatum inwhich E. angustifolium can be constant but isalways subordinate to E. vaginatum.
2. Tussocky E. vaginatum with very patchy Sphagnumcapillifolium, constantDeschampsia flexuosa and mounds of Vaccinium myrtillus and/or Empetrumnigrum nigrum. Calluna vulgaris usually absent butcan be present as scatteredsprigs at low frequency.North-western stands alsofeature prominent Poly-trichum commune.
1. Vegetation dominated byEriophorum angustifolium inwhich Sphagnum cuspidatum and/or Drepanocladus fluitans can be prominent. Bog poolsand erosion hagg runnels with-in blanket peat.
Fig 2. Key to vegetation with constant Sphagnum spp. and dominated by Eriophorum vaginatum and/or E. angustifolium
2a. It can be difficult to separate richer forms of theM20b sub-community frompoor and degraded stands ofthe M19 blanket mire, sincethere is a continuum of vegetation types between these two communities with increasing disturbance to thelatter. Generally, if C. vulgaris is constant with a reasonablyintact Sphagnum flora thiscommunity can be categorisedwith the M19 mires, though E. vaginatum may be visuallydominant.
This community is typical ofrecent or disturbed bog pools orforms an early seral stage in thetransition from exposed peatback to mire vegetation. Poorerstands of the M2b Sphagnumrecurvum bog pool can be verysimilar to Sphagnum-rich M3stands, reflecting the transitionalcontinuum between these communities.
M20b Eriophorum vagina-tum blanket and raised mire,Calluna vulgaris – Cladonia spp. sub-community
M19 Calluna vulgaris –Eriophorum vaginatum blanket mire
Mires Figure 2
13
2. M
oss
laye
r d
omin
ated
by
Sp
hag
nu
m r
ecu
rvu
m,
S. c
usp
idat
um
an
dP
olyt
rich
um
com
mu
ne,
nev
er S
. squ
arro
sum
. Car
excu
rta
can
be
abu
nd
ant
inso
me
stan
ds
(DO
MIN
2-9
)bu
t S
. war
nst
orfi
i n
ever
p
rese
nt.
1. C
arex
ros
trat
a co
nst
ant
and
pro
min
ent.
Fig
3. K
ey t
o co
mm
un
itie
s w
ith
con
stan
tS
ph
agn
um
spp
. an
d d
omin
ated
by
sed
ges
or t
all
rush
es
M4
Car
ex r
ostr
ata
–S
ph
agn
um
rec
urv
um
mir
e
4. V
eget
atio
n d
omin
ated
by
tall
ru
shes
; Ju
ncu
s ef
fusu
s an
d/o
r Ju
ncu
s ac
uti
flor
us
usu
ally
wit
h C
arex
ech
inat
a
but
this
som
etim
es v
ery
spar
se. A
ssoc
iate
s in
clu
de:
Pol
ytri
chu
m c
omm
un
e,P
oten
till
a er
ecta
,Vio
lap
alu
stri
s ov
er a
mos
s la
yer
dom
inat
ed b
yS
ph
agn
um
pal
ust
re a
nd
eith
er S
. rec
urvu
m o
r S.
aur
icul
atum
.
1a. C
arex
ros
trat
aab
sen
t or
pres
ent
only
at
low
fre
quen
cy.
4a. T
all
rush
es a
bsen
t or
only
very
sp
arse
an
d p
atch
y.
3. S
ph
agn
um
squ
arro
sum
co
nst
ant
wit
h a
t le
ast
thre
eof
: Pot
enti
lla
pal
ust
ris,
Car
ex n
igra
,Eri
oph
oru
m
angu
stif
oliu
m,S
ucc
isa
pra
ten
sis,
Au
laco
mn
ium
pal
ust
re.
3a. S
ph
agn
um
war
nst
orfi
i co
nst
ant
wit
h a
t le
ast
thre
eof
Car
ex n
igra
,Ep
ilob
ium
pal
ust
re,S
elag
inel
la
sela
gin
oid
es,V
iola
pal
ust
ris,
Au
laco
mn
ium
pal
ust
re,
Cal
lier
gon
cu
spid
atu
m,
Rh
izom
niu
m p
seu
dop
un
cta-
tum
an
d S
ph
agn
um
ter
es.
5. V
eget
atio
n d
omin
ated
by
Car
ex c
urt
a w
ith
con
-st
ant
Sp
hag
nu
m r
uss
owii
and
at
leas
t tw
o of
Car
exec
hin
ata,
Eri
oph
oru
man
gust
ifol
ium
,Vio
la
pal
ust
ris,
S. p
apil
losu
m.
M5
Car
ex r
ostr
ata
–S
ph
agn
um
squ
arro
sum
mir
e
Flu
sh o
r fl
oati
ng
raft
ove
r li
quid
pea
t. O
ften
for
ms
stag
e in
th
e tr
ansi
tion
to
open
wat
er o
r as
par
t of
aco
mp
lex
mos
aic
wit
h o
ther
C. r
ostr
ata
dom
inat
ed c
om-
mu
nit
ies
(M9,
S9,
S27
).
M8
Car
ex r
ostr
ata
–S
ph
agn
um
war
nst
orfi
i m
ire
Mon
tan
e fl
ush
veg
etat
ion
,al
mos
t al
way
s be
twee
n
400
man
d 8
00 m
asl
.
M6
Car
ex e
chin
ata
–S
ph
agn
um
rec
urv
um
/au
ric-
ula
tum
mir
e, M
6c J
un
cus
effu
sus
sub-
com
mu
nit
y an
d M
6d J
. acu
tifl
oru
s su
b-co
mm
un
ity
M7
Car
ex c
urt
a –
Sp
hag
nu
m r
uss
owii
mir
e
Mon
tan
e fl
ush
veg
etat
ion
,al
mos
t al
way
s be
twee
n
650
man
d 1
100
m a
sl i
nce
ntr
al S
cotl
and
.
M6
Car
ex e
chin
ata
–S
ph
agn
um
rec
urv
um
/au
ricu
latu
m m
ire,
M6a
Car
ex e
chin
ata
sub-
com
mu
nit
y an
dM
6b C
arex
nig
ra –
Nar
du
s st
rict
a su
b-co
mm
un
ity
Sta
nd
s w
ith
abu
nd
ant
Car
ex n
igra
,Eri
o-p
hor
um
an
gust
ifol
ium
and
Ju
ncu
s sq
uar
rosu
s m
ay b
e tr
ansi
tion
al
to w
ette
r fo
rms
of t
he
U6
J. s
quar
rosu
s –
Fes
tuca
ovi
na
gras
slan
d.
5a. C
arex
cu
rta
abse
nt
or v
ery
rare
. Car
exec
hin
ata
con
stan
t ov
er a
mos
s la
yer
dom
inat
ed b
y S
ph
agn
um
pal
ust
rean
d e
ith
er S
.rec
urv
um
or S
. au
ricu
latu
m.
Oth
er s
edge
s fr
equ
ent
incl
ud
ing
C. p
anic
ea,
C. n
igra
and
Eri
opho
rum
angu
stifo
lium
.Nar
du
sst
rict
a an
d J
un
cus
squ
arro
sus
can
be
very
fre
quen
t in
so
me
stan
ds.
2a. S
ph
agn
um
rec
urv
um
ab
sen
t or
can
be
pre
sen
t bu
tis
alw
ays
subo
rdin
ate
toot
her
Sp
hag
nu
m s
pp
.
Mires Figure 3
14
M1 Sphagnum auriculatum bog pool
1a. Bog pool dominated bySphagnum cuspidatum and/orS. recurvum. S. auriculatumnever present. Scattered Eriophorum angustifolium throughout pool; Erica tetralix,Drosera rotundifolia and othervascular species around margins.
M2 Sphagnum cuspidatum/recurvum bog pool
1. Bog pool dominated by Sphagnum auriculatum and S. cuspidatum, usually withsome Menyanthes trifoliata and Eriophorum angustifolium.
Fig 4. Key to bog pools dominated by open Sphagnum carpets
As temporary pools infill,Eriophorum angustifolium increases in prominence. Suchpools can exist in all transition-al stages between M2 and M3bog pool floristics.
Fig 5. Key to semi-aquatic rills and flushes dominated byPotamogeton polygonifolius and/or Montia fontana
1. Flush vegetation dominatedby Potamogeton polygonifoliuswith Hypericum elodes, Ranun-culus flammula and Juncus bulbosus.
M29 Hypericum elodes –Potamogeton polygonifolius soakway
M35 Ranunculus omiophyllus –Montia fontana rill
This community has been poorly sampled from the north. Hypericum elodes is abundantin this community across south-west Britain but declines to thenorth and is absent from moststands north of the ScottishBorders except for occasionaloutliers in the Western Isles.
This community has been poorly sampled from the northof Britain. Stands similar in floristics to the M35 rills butlacking R. omiophyllus areoccasional along ditch-lines atthe margins of improved landin lowland areas.
1a. Rills and spring-head vegetation dominated by Montiafontana and Ranunculus omio-phyllus, usually with Ranun-culus flammula and some of:Juncus bulbosus, J. articulatus,Potamogeton polygonifolius,Myosotis secunda and Agrostisstolonifera.
Mires Figure 4
Mires Figure 5
15
2. M
oss
carp
et d
omin
ated
by
Cra
ton
euro
n c
omm
uta
tum
or o
ccas
ion
ally
by
C. f
ilic
inu
m.
1. M
onta
ne
or s
ub-
mon
tan
ebr
yop
hyt
e-ri
ch s
pri
ng-
hea
ds
dom
inat
ed b
y C
rato
neu
ron
com
mu
tatu
m a
nd
/or
Ph
ilon
otis
fon
tan
a.
Fig
6. K
ey t
o op
en, b
ryop
hyt
e-ri
ch s
pri
ngs
an
d f
lush
es
M38
Cra
ton
euro
n
com
mu
tatu
m –
Car
ex
nig
ra s
pri
ng
4. O
pen
mat
dom
inat
ed
by A
nth
elia
jula
cea
wit
h
con
stan
t S
ph
agn
um
au
ricu
latu
m,M
arsu
pel
laem
argi
nat
a,S
cap
ania
u
nd
ula
ta a
nd
Des
cham
psi
ace
spit
osa.
1a. M
onta
ne
spri
ngs
or
rill
sin
wh
ich
Cra
ton
euro
n
com
mu
tatu
m a
nd
Ph
ilon
otis
fon
tan
aar
e ab
sen
t or
ver
ysp
arse
.
2a. C
rato
neu
ron
com
mu
tatu
mab
sen
t or
on
ly p
rese
nt
at l
owfr
equ
ency
. Ph
ilon
otis
fon
tan
aco
nst
ant
wit
h t
wo
or m
ore
of:
Sax
ifra
ga s
tell
aris
,Sca
pan
iau
nd
ula
ta,D
esch
amp
sia
cesp
itos
a,D
icra
nel
la p
alu
s-tr
is,S
tell
aria
als
ine,
Spha
gnum
aur
icul
atum
.
Typ
ical
ly f
rom
bas
e-ri
char
eas
inac
cess
ible
to
graz
ing
as t
his
can
des
troy
th
ebr
yop
hyt
e m
at.
M32
Ph
ilon
otis
fon
tan
a –
Sax
ifra
ga s
tell
aris
sp
rin
gM
31 A
nth
elia
jula
cea
–S
ph
agn
um
au
ricu
latu
m
spri
ng
M34
Car
ex d
emis
sa –
Koe
nig
ia i
slan
dic
afl
ush
Th
is c
omm
un
ity
ison
ly r
ecor
ded
fro
mth
e Tr
otte
rnis
h R
idge
on S
kye.
It
is d
escr
ibed
from
just
4 s
amp
les.
5a. B
ryop
hyt
e m
atw
ith
op
en a
reas
of
ston
y gr
oun
d. C
arex
dem
issa
an
d K
oen
igia
isla
nd
ica
con
stan
tw
ith
Des
cham
psi
ace
spit
osa,
Sax
ifra
gast
ella
ris
and
S
cap
ania
un
du
lata
.
3a. S
pri
ngs
ove
rwh
elm
ingl
yd
omin
ated
by
Cra
ton
euro
nco
mm
uta
tum
wit
h
Ph
ilon
otis
fon
tan
a ra
re t
ooc
casi
onal
. Sm
all
sed
ges
are
scar
ce a
nd
th
e d
iver
sity
of
vasc
ula
r p
lan
ts q
uit
e p
oor,
usu
ally
in
clu
din
g C
ard
amin
ep
rate
nsi
s,F
estu
ca r
ubr
a an
d A
gros
tis
stol
onif
era.
3. S
pec
ies-
rich
sp
rin
gs i
nw
hic
h C
arex
sp
p.a
re f
re-
quen
t, t
hou
gh s
par
se, e
spe-
cial
ly C
. nig
ra,C
. pan
icea
and
C. d
emis
sa. D
iver
seh
erbs
in
clu
din
g so
me
of:
Car
dam
ine
pra
ten
sis,
Leon
tod
on a
utu
mn
alis
,Tr
ifol
ium
rep
ens
and
Pol
ygon
um
viv
ipar
um
.P
hil
onot
is f
onta
na
can
be
freq
uen
t in
th
e m
oss
carp
et.
Lig
ht
graz
ing
is i
mp
orta
nt
inke
epin
g th
e m
at o
pen
an
dm
ain
tain
ing
div
ersi
ty.
Ver
y va
riab
le c
omm
un
ity,
thou
gh p
rese
nce
of
P. f
onta
na
reli
able
. Low
er a
ltit
ud
eex
amp
les
ofte
n l
ack
Sax
ifra
ga s
tell
aris
an
d
grad
e in
to t
he
Cra
ton
euro
n
com
mu
tatu
m s
pri
ngs
, M
37, M
38.
4a. M
onta
ne
spri
ngs
an
dri
lls
lack
ing
An
thel
iaju
lace
a.
5. S
pon
gy b
ryop
hyt
e ca
rpet
s d
omin
ated
by
Poh
lia
wah
len
berg
ii v
ar. g
laci
alis
.C
onst
ants
in
clu
de:
Sax
ifra
gast
ella
ris,
Des
cham
psi
a ce
spi-
tosa
an
d P
ohli
a lu
dw
igii
.C
eras
tiu
m c
eras
toid
es
can
be
freq
uen
t.
M33
Poh
lia
wah
len
berg
ii
var.
gla
cial
is s
pri
ng
M37
Cra
ton
euro
n
com
mu
tatu
m –
Fes
tuca
ru
bra
spri
ng
Mires Figure 6
16
2. E
riop
hor
um
an
gust
ifol
ium
d
omin
ant
on o
pen
ero
ded
pea
t, e
spec
iall
y ar
oun
dh
aggs
.
1. V
eget
atio
n
over
wh
elm
ingl
y d
omin
ated
by E
riop
hor
um
sp
p; C
arex
sp
p. n
ever
pro
min
ent.
Fig
7. K
ey t
o ve
geta
tion
dom
inat
ed b
y se
dge
s,C
are
x a
nd
Eri
oph
oru
msp
p.,
in w
hic
hS
ph
agn
um
spp
. are
abs
ent
or i
nfr
equ
ent
in t
he
swar
d
M3
Eri
oph
oru
m
angu
stif
oliu
mbo
g p
ool
2a. E
riop
hor
um
vag
inat
um
d
omin
ant
and
usu
ally
tu
ssoc
ky. O
ften
ext
ensi
vem
ire.
M9
Car
ex r
ostr
ata
– C
allie
rgon
cusp
idat
um
/gig
ante
um
mir
eM
12 C
arex
sax
atil
ism
ire
Car
ex d
ioic
a m
ay b
eab
sen
t or
dif
ficu
lt t
ofi
nd
in
poo
rer
stan
ds.
C. d
emis
sa m
ayre
pla
ce C
. lep
idoc
arp
ain
hig
her
alt
itu
de/
less
ba
se-r
ich
sta
nd
s.
5a. T
wo
or m
ore
of
Car
ex d
ioic
a,C
. pan
-ic
ea,C
. pu
lica
ris
and
C. l
epid
ocar
pa
con
-st
ant.
Sax
ifra
gaai
zoid
es a
t lo
w
freq
uen
cy.
M11
Car
ex d
emis
sa –
Sax
ifra
ga a
izoi
des
mir
eM
20 E
riop
hor
um
vag
inat
um
blan
ket
and
rai
sed
mir
e
3. C
arex
ros
trat
a p
rom
inen
tin
her
b-ri
ch s
war
ds
over
bulk
y m
osse
s, o
ften
for
min
gfl
oati
ng
raft
s. C
onst
ants
incl
ud
e: E
riop
hor
um
an
gust
ifol
ium
,Gal
ium
pal
ust
re,M
enya
nth
es
trif
olia
ta,P
oten
till
a p
alu
stri
s an
d C
alli
ergo
n c
usp
idat
um
.
1a. V
eget
atio
n d
omin
ated
by
Car
ex s
pp
. Eri
oph
oru
man
gust
ifol
ium
can
be
con
stan
t bu
t n
ever
dom
inan
t.
4. C
arex
sax
atil
is d
omin
ant,
oth
er s
edge
s su
bord
inat
e.C
onst
ants
in
clu
de:
Th
alic
tru
m a
lpin
um
,H
yloc
omiu
m s
ple
nd
ens,
Pol
ygon
um
viv
ipar
um
and
An
eura
pin
guis
.
Mon
tan
e fl
ush
es o
ver
700
m a
sl.
5. S
axif
raga
aiz
oid
es
and
Car
ex d
emis
sa c
onst
ant.
Th
is c
omm
un
ity
usu
ally
resu
lts
from
deg
rad
ed b
lan
-ke
t m
ire,
M19
. Sp
ecie
s-p
oor,
but
a ra
nge
of
tran
siti
onal
M
20-M
19 s
tan
ds
occu
rs.
Oft
en o
ccu
rs i
n c
omp
lex
mos
aics
wit
h M
5 an
d t
he
S27
sw
amp
in
wh
ich
th
e d
iagn
osti
c h
erbs
are
ver
ysi
mil
ar, t
hou
gh l
acki
ng
the
mos
s ca
rpet
of
M9.
3a. O
pen
veg
etat
ion
d
omin
ated
by
shor
t se
dge
sin
clu
din
g at
lea
st t
hre
e of
: C
arex
pan
icea
,C. d
emis
sa,
C. d
ioic
a,C
. lep
idoc
arp
a,C
. pu
lica
ris,
C. s
axat
ilis
,C
. ech
inat
a,D
rep
anoc
lad
us
revo
lven
s.
4a. C
arex
sax
atil
is
abse
nt.
Fre
quen
t sp
ecie
s:
Car
ex p
anic
ea,C
. pu
lica
ris,
Dre
pan
ocla
du
s re
volv
ens,
Pin
guic
ula
vu
lgar
is,A
neu
rap
ingu
is,C
amp
yliu
m
stel
latu
m a
nd
Sel
agin
ella
sela
gin
oid
es.
M10
Car
ex d
ioic
a –
Pin
guic
ula
vu
lgar
ism
ire
Mires Figure 7
17
2. J
un
cus
subn
odu
losu
s co
nst
ant,
usu
ally
wit
h
oth
er J
un
cus
spp
., S
ucc
isa
pra
ten
sis,
Pot
enti
lla
erec
ta,
Car
ex p
anic
ea a
nd
Cal
lier
gon
cu
spid
atu
m.
1. S
choe
nu
s n
igri
can
sco
nst
ant
and
abu
nd
ant.
Fig
8. K
ey t
o ve
geta
tion
in
wh
ich
Mol
inia
ca
eru
lea
is c
onst
ant
and
str
uct
ura
lly
imp
orta
nt
but
Sp
ha
gnu
msp
p. a
re g
ener
ally
lac
kin
g
2a. S
choe
nu
s n
igri
can
s u
sual
ly a
bun
dan
t w
ith
som
eof
: Eri
ca t
etra
lix,
Nar
thec
ium
ossi
frag
um
,An
agal
lis
ten
ella
,Dro
sera
rot
un
dif
olia
an
d g
ener
ally
som
e S
ph
agn
um
au
ricu
latu
man
d/o
r S
. su
bnit
ens.
J.
su
bnod
ulo
sus
abse
nt.
M15
Sci
rpu
s ce
spit
osu
s –
Eri
ca t
etra
lix
wet
hea
thM
24 M
olin
ia c
aeru
lea
–C
irsi
um d
isse
ctum
fen-
mea
dow
5a. M
olin
ia c
aeru
lea
and
Pot
enti
lla
erec
ta
only
con
stan
ts i
n g
en-
eral
ly q
uit
e p
oor
vege
-ta
tion
. Ass
ocia
tes
can
incl
ud
e fr
equ
ent
Jun
cus
acu
tifl
oru
s an
d s
par
se h
erbs
su
chas
Su
ccis
a p
rate
nsi
s,C
irsi
um
pal
ust
rean
d/o
r E
rica
tet
rali
x.
M26
Mol
inia
cae
rule
a–
Cre
pis
pal
ud
osa
mir
eM
14 S
choe
nu
s n
igri
can
s –
Nar
thec
ium
oss
ifra
gum
mir
e
3. C
allu
na
vulg
aris
an
d E
rica
tet
rali
x co
nst
ant
and
usu
ally
abu
nd
ant
wit
h
Sci
rpu
s ce
spit
osu
san
d
Pot
enti
lla
erec
ta.
1a. S
choe
nu
s n
igri
can
s ab
sen
t or
rar
e, t
hou
gh m
aybe
loc
ally
fre
quen
t in
flu
shed
wet
hea
th.
4. M
olin
ia c
aeru
lea
–d
omin
ated
fen
wit
h c
onst
ant
Cir
siu
m d
isse
ctu
m, u
sual
lyw
ith
Ju
ncu
s su
bnod
ulo
sus,
som
etim
es J
. art
icu
latu
s or
J. i
nfl
exu
s. A
ssoc
iate
sin
clu
de
poo
r fe
n h
erbs
, p
arti
cula
rly
Val
eria
na
dio
ica
and
Su
ccu
sa p
rate
nsi
s.
5. R
ich
Mol
inia
cae
rule
a fe
n w
ith
Car
ex n
igra
an
d a
tle
ast
thre
e of
: Cre
pis
p
alu
dos
a,C
arex
pan
icea
,C.
pu
lica
ris,
Val
eria
na
dio
ica,
Su
ccis
a p
rate
nsi
s,F
ilip
end
ula
ulm
aria
an
d R
anu
ncu
lus
acri
s.
3a. C
allu
na
vulg
aris
ab
sen
t or
pre
sen
t at
low
fr
equ
ency
. Eri
ca t
etra
lix
may
be
freq
uen
t in
th
e M
25a
sub-
com
mu
nit
y
4a. C
irsi
um
dis
sect
um
an
d J
un
cus
subn
odu
losu
sab
sen
t or
rar
e.
M25
Mol
inia
cae
rule
a–
Pot
enti
lla
erec
ta m
ire
Exi
stin
g re
cord
s li
mit
th
isco
mm
un
ity
to t
he
Nor
thP
enn
ines
an
d L
ake
Dis
tric
t,th
ough
it
may
ext
end
in
toth
e S
outh
ern
Up
lan
ds.
Th
is c
omm
un
ity
is m
ain
ly
in s
outh
an
d e
ast
Bri
tain
,th
ough
sed
ge-r
ich
sta
nd
s of
M25
fou
nd
in
sou
th-w
est
Sco
tlan
d a
nd
th
e W
este
rnIs
les
may
res
embl
e th
eJu
ncu
s ac
uti
flor
us
–E
rica
tetr
alix
sub
-com
mun
ity
M24
c.
M13
Sch
oen
us
nig
rica
ns
–Ju
ncu
s su
bnod
ulo
sus
mir
e
Mires Figure 8
18
Oen
anth
e cr
ocat
ais
oft
enab
sen
t fr
om s
tan
ds
of t
his
com
mu
nit
y in
th
e n
orth
an
dw
est
of S
cotl
and
.
1. I
ris
pse
ud
acor
us
con
stan
tan
d g
ener
ally
dom
inan
t,u
sual
ly w
ith
con
stan
tO
enan
the
croc
ata,
Fili
pend
ula
ulm
aria
and
Poa
tri
vial
is.
Fig
9. K
ey t
oJu
ncu
ssp
p. a
nd
tal
l h
erb
dom
inat
ed f
ens
in w
hic
hS
ph
agn
um
spp
. are
nev
er p
rom
inen
t
M27
Fil
ipen
du
la u
lmar
ia–
An
geli
ca s
ylve
stri
sm
ire
M22
Ju
ncu
s su
bnod
ulo
sus
–C
irsi
um p
alus
tre
fen-
mea
dow
M23
Ju
ncu
s ef
fusu
s/ac
uti
flor
us
– G
aliu
m p
alu
stre
rush
-pas
ture
2. F
ilip
end
ula
ulm
aria
con
stan
t an
d p
rom
inen
t w
ith
tal
l fe
n h
erbs
in
clu
din
gA
nge
lica
syl
vest
ris,
Val
eria
na
offi
cin
alis
and
Ru
mex
ace
tosa
.
1a. I
ris
pse
ud
acor
us
abse
nt
or a
t lo
w f
requ
ency
in
th
esw
ard
.
3. F
en-m
ead
ow d
omin
ated
by J
un
cus
subn
odu
losu
sof
ten
wit
h f
requ
ent
J.in
flex
us
and
/or
J. ar
ticu
latu
s.C
onst
ants
in
clu
de:
Men
tha
aqu
atic
a, C
irsi
um
pal
ust
rean
d C
alli
ergo
n c
usp
idat
um
.
2a. F
ilip
end
ula
ulm
aria
can
be o
ccas
ion
al t
o fr
equ
ent
but
nev
er p
rom
inen
t. V
eget
atio
nd
omin
ated
by
tall
ru
shes
usu
ally
wit
h c
onst
ant
Hol
cus
lan
atu
san
d L
otu
s u
ligi
nos
us.
3a. V
eget
atio
n d
omin
ated
by
Jun
cus
effu
sus
and
/or
J. a
cu-
tifl
oru
sw
ith
con
stan
t G
aliu
mp
alu
stre
and
oth
er p
oor-
fen
asso
ciat
es, m
ost
usu
ally
Cir
siu
m p
alu
stre
, Ru
mex
ac
etos
a, E
pil
obiu
m p
alu
stre
,M
enth
a aq
uat
ica
and
Ran
un
culu
s fl
amm
ula
.
M28
Iri
s p
seu
dac
oru
s–
Fil
ipen
du
la u
lmar
iam
ire
In w
este
rn B
rita
in M
olin
iaca
eru
lea
can
be
loca
lly
abu
n-
dan
t in
th
is c
omm
un
ity.
Mires Figure 9
This bog pool community typically consists offloating masses or soft wet carpets of Sphagnumspp., mainly Sphagnum auriculatum (includingvar. inundatum) and S. cuspidatum, with scat-tered vascular plants growing on or through themor in areas of open water between. Locally, thebright orange-yellow S. pulchrum is conspicuous.S. recurvum is rare in contrast with the Sphagnumcuspidatum/recurvum bog pool community (M2).Other bryophytes are generally scarce, butCladopodiella fluitans is characteristic at low frequencies and Gymnocolea inflata can also bepresent.
The commonest vascular plants are Meny-anthes trifoliata and Eriophorum angustifoliumwhich together make up a cover of less than 30%.In open water Sphagnum cover is reduced andUtricularia species, usually U. minor or locally U. intermedia, are sometimes present. In shallowwater Rhynchospora alba is characteristic, and R.fusca is found occasionally in this community.Narthecium ossifragum and Drosera spp., particu-larly D. rotundifolia, are also occasionally present.In some areas Carex limosa is frequent, but is shy
19
3 Mire community descriptions and sub-community keys
M1 Sphagnum auriculatumbog pool community
in flowering. Around the pool margins Moliniacaerulea can extend down from the mire surfacealthough its cover is generally low.
This community is confined to pools and wetterhollows on ombrogenous and topogenous mireswith base-poor and oligotrophic raw peat soils inthe more oceanic parts of Britain. It is a widespreadcomponent in the Scirpus cespitosus – Eriophorumvaginatum blanket mire (M17) in the far west ofBritain including western Scotland, parts of theLake District, Wales, and the South-West Peninsula,and the Narthecium ossifragum – Sphagnum papil-losum valley mire (M21) in south-western valleymires with a high water table, particularly in theNew Forest and Dorset.
The wetness gives some protection to this vegetation where mires are grazed or burned, butit has been reduced on many sites by draining andcutting of the peat. It has been widely lost whereErico-Sphagnion communities have been con-verted to Ericion heaths or their degraded deriva-tives. Shallow peat-digging can create flooded hol-lows which become suitable for recolonisation bySphagnum spp., Rhynchospora alba and Droseraspp., but such locally reconstituted stands oftenlie in much-modified mire contexts.
No sub-communities.
This community is typically dominated by softwet carpets of Sphagnum cuspidatum or S. recurvum, or both. S. pulchrum occurs verylocally, occasionally with S. tenellum, S. magel-lanicum or S. papillosum. Sphagnum auriculatumis rare in contrast with the Sphagnum auricula-tum bog pool community (M1). Other bryo-phytes are scarce but Polytrichum commune orAulacomnium palustre can form occasionalpatches and there may be scattered leafy hepatics.Vascular plants occur as scattered individualswith Eriophorum angustifolium and Erica tetralixboth constant; the former often extending intodeeper pools and the latter confined to drier areas.Drosera rotundifolia is frequent and Nartheciumossifragum occasional. Andromeda polifolia,where present, is distinctive of this vegetationtype particularly around pool margins, and togeth-er with Rhynchospora alba it forms a clear sub-
community. There may be some sedges includingCarex limosa, C. curta and C. magellanica.
The community is typically found in pools andlawns on very wet and base-poor raw peats onombrogenous and topogenous mires in the lessoceanic parts of Britain. Its range coincides closely with that of the Erica tetralix – Sphagnumpapillosum mire (M18) and it typically forms thepool, wet hollow and lawn elements in that community (and its degraded derivatives) on lowland raised bogs, on locally raised areas within low altitude blanket mires and in base-poorbasin mires. It occurs from Wales up through theScottish Borders and south-west Scotland withsome localities in north-east Scotland.
This community has been reduced by wide-spread drainage and cutting of mires, so that oftenjust small and modified fragments remain withinpredominantly agriculture landscapes. Howeverthis community readily colonises shallow floodedworkings and appears to have expanded its cover-age in sites where there has been some agriculturalenrichment of the water.
20
M2 Sphagnum cuspidatum/recurvum bog pool community
M2a
Rhynchospora albasub-community
Sphagnum cuspidatum is the typical dominant in theSphagnum carpet. Eriophorumangustifolium and Erica tetralixjoin Rhynchospora alba andAndromeda polifolia as con-stants, Drosera rotundifolia isfrequent and D. anglica or D. intermedia occasional.
This sub-community is morewidely distributed on active,undisturbed raised mires.
M2b
Sphagnum recurvum/cuspidatum sub-community
Sphagnum recurvum is constant with S. cuspidatumand often the more abundant of the two. Eriophorum angusti-folium, Erica tetralix andDrosera rotundifolia maintaintheir high frequency andVaccinium oxycoccos is a good preferential. Polytrichum commune and Aulacomniumpalustre can occur sporadicallyin slightly drier areas withsome Calluna vulgaris andEriophorum vaginatum. Molinia caerulea may be locally prominent.
This sub-community is morerestricted to soligenous areasand disturbed basin mires.
Sphagnum recurvum usuallyabsent but Rhynchospora alba and Andromeda polifolia veryfrequent.
Sphagnum recurvum constantand often abundant with no Rhynchospora alba and onlyoccasional Andromeda polifolia.
M2
Eriophorum angustifolium is dominant here inswards where other vascular species andSphagnum spp. play a relatively minor role. Itsshoot density is very variable, as is the sward heightwhich may be very short or up to half a metre ormore. Usually shoots reach approximately 30 cm.
Other vascular plants attain only occasional frequency but there can be scattered small tus-socks of Eriophorum vaginatum or Moliniacaerulea or sparse individuals of Drosera rotundi-folia, Erica tetralix or Empetrum nigrum ssp.nigrum. Bryophyte cover is also very variable andthere are no constant species but Drepanocladusfluitans may be frequent, often growing sub-merged. Sparse shoots or small tufts of Sphagnumspp. may be present, usually S. cuspidatum butsometimes S. recurvum or S. papillosum.
This community is typically found as small standson barer exposures of acid raw peat soils indepressions, erosion channels or shallow peat cuttings on a wide range of mire types. It can befound in natural hollows on surfaces of more orless intact mires but is more common among erosion features where the peat has been worndown in gullies or redistributed. It is also some-times associated with abandoned peat workingson lowland mires. The community is particularlyassociated with the eroded blanket mire in thenorth-west of Britain, being a common feature intracts of the Calluna vulgaris – Eriophorum vagi-natum and Eriophorum vaginatum mires (M19and M20), and it is widespread but local in low-land Erico-Sphagnion mires (M18, M21) andEricion wet heaths (M15, M16). This communitymay represent a seral stage in the redevelopmentof active mire vegetation following disruption.
No sub-communities.
21
M3 Eriophorum angustifoliumbog pool community
This mire typically has a cover of sedges over acarpet of semi-aquatic Sphagnum spp. Carex ros-trata is the commonest sedge, usually forming arather open cover of shoots, but it can be accom-panied by C. curta, C. lasiocarpa, C. limosa or C. nigra (the first two especially can be locallyprominent). Carex chordorrhiza is a rare associate.Occasionally the taller element of the vegetationalso has Eriophorum angustifolium, Juncuseffusus or J. acutiflorus. There is generally anextensive wet carpet of Sphagnum spp. S. recurvum and S. cuspidatum are usually themost frequent and abundant species and S. auric-ulatum is also common. Sphagnum palustre isoccasional, with sparse records for Sphagnumsubnitens and S. papillosum. S. squarrosum andS. teres are characteristically rare, which providesa good contrast with Carex rostrata – Sphagnumsquarrosum mire (M5). Other bryophytes are few,but Polytrichum commune is very frequent form-ing scattered patches. Aulacomnium palustre andCalliergon stramineum are very sparse.
Scattered through the ground cover are indi-viduals of an impoverished poor-fen herb flora.The commonest species are Agrostis canina ssp.canina and A. stolonifera (which may be locally
abundant as stoloniferous mats), Molinia caerulea,Potentilla erecta, Galium palustre, Rumex ace-tosa, Viola palustris, Succisa pratensis andStellaria alsine. Usually only one or two of theseare present in any one stand. Potentilla palustris,Menyanthes trifoliata and Equisetum fluviatilealso may occur occasionally.
This community is characteristic of pools andseepage areas on raw peat soils of topogenous andsoligenous mires where the waters are fairly acidand only slightly enriched. It can occur in bogpools on the surface of basin (and sometimesraised) mires, but is more common in obviouslysoligenous areas as in mire laggs and the wettestparts of water-tracks. Enrichment is slight and thepH is typically around 4. The community is ofwidespread but local occurrence throughout thenorth-west of Britain and probably remains asremnants in drained mire systems in the lowlands.
The place of this community in the terrestrial-ising succession is not clear and the vegetationmay be very stable provided the high water tableand modest irrigation are maintained. Drainageresults in the demise of the more aquaticSphagnum spp. and perhaps a transition to the Carex echinata – Sphagnum recurvum/ auric-ulatum mire (M6), and with grazing, may result ina spread of Juncus dominance.
No sub-communities.
22
M4 Carex rostrata –Sphagnum recurvum mire
This mire is fairly heterogeneous and is charac-terised overall by the dominance of sedges withscattered poor-fen herbs over a patchy carpet ofmoderately base-tolerant Sphagnum spp. Thecommonest species throughout are Carex rostrataand C. nigra, with the former generally moreextensive. Carex lasiocarpa can be locally promi-nent and C. curta is occasionally found. Carexlimosa and C. diandra are typically absent in con-trast with the Carex rostrata – Calliergon cuspida-tum/giganteum mire (M9).
Other vascular plants are often limited to scat-tered individuals, but the most frequent overallare Potentilla palustris, Eriophorum angustifoli-um, Menyanthes trifoliata, Galium palustre andsuch typical poor-fen herbs as Succisa pratensis,Viola palustris, Ranunculus flammula, Epilobiumpalustre and Lychnis flos-cuculi. Juncus effususcan be frequent, as can Molinia caerulea andMyrica gale.
The bryophyte carpet helps define the Carex –Sphagnum squarrosum mire against closely relat-ed vegetation types. Sphagnum spp. are at leastpatchily prominent. Especially distinctive is thepresence of Sphagnum squarrosum and S. teres. Inaddition S. recurvum and S. palustre are frequent-ly encountered and S. cuspidatum and S. auricu-
latum are occasionally found. Sphagnum contor-tum is rare in contrast with the Carex rostrata –Calliergon cuspidatum/giganteum mire (M9).Other common bryophytes are Aulacomniumpalustre and Calliergon stramineum.
This mire is typically found as a floating raft oron soft, spongy peats in topogenous mires and insoligenous sites with mildly acid, only moderate-ly calcareous and rather nutrient-poor waters; thepH range is from about 4 to above 6. It is charac-teristically found in zonations and mosaics, thesimplest being open water transitions aroundlakes. It can also be found around springs, seepagelines and streams where it can form part of a mix-ture of poor- and rich-fen communities. The com-munity has a widespread but fairly local distribu-tion in north-western parts of Britain. It was prob-ably once much more widespread in the lowlandsouth and east where relic stands may still occur.
The peat under this community is often verysoft which gives the vegetation a measure of pro-tection against the trampling and grazing effects oflarger herbivores, although damage may occurduring periodic dry spells. Where the communityruns onto firmer peats around the margins of lakes or basins, the vegetation tends to pass to theCarex echinata – Sphagnum recurvum/auricula-tum mire (M6). The effect of grazing on these tran-sitions may favour the spread of Juncus effusus.
No sub-communities.
23
M5 Carex rostrata – Sphagnumsquarrosum mire
This community has a distinct general characterbut includes a wide variation in composition,expressed here in four sub-communities. Ess-entially it is a poor-fen with small sedges or rush-es dominating over a carpet of oligotrophic andbase-intolerant Sphagnum spp. The constants arevery few. Among vascular plants only Carex echi-nata has a uniformly high frequency, but C. nigra and C. panicea are common, and C.demis-sa occasional. There are two negative characterswhich aid definition of this community. Firstly,the general absence of more calcicolous Carexspecies, e.g. C. dioica, C. pulicaris, C. lepidocarpaand C. flacca, helps to separate this communityfrom the Caricion davallianae rich fens (M9 toM12), and secondly, only local occurrence ofspecies like C. rostrata and C. curta marks the veg-etation off from communities like the Carex ros-trata – Sphagnum recurvum mire (M4).
The most common vascular associates aregrasses and poor-fen dicotyledons. Among thegrasses, Agrostis canina ssp. canina and Moliniacaerulea are the most common but Anthoxanthum odoratum is also frequent. Commonly occurringpoor-fen dicotyledons include Viola palustris andPotentilla erecta, and occasionally one or more ofGalium saxatile, G. palustre, Cirsium palustre,Epilobium palustre, Succisa pratensis, Ranun-culus flammula or Cardamine pratensis may bepresent. Sometimes species such as Narthecium
ossifragum, Drosera rotundifolia and Erica tetralixare found. The rushes Juncus acutiflorus and J. effusus may each be dominant in particular sub-communities.
A ground carpet of Sphagnum spp. is promi-nent and it is most frequently composed of S. recurvum and S. auriculatum, with occasionaloccurrence of S. subnitens and S. papillosum.There are only a few other commonly occurringbryophyte species. Polytrichum commune is veryfrequent, Rhytidiadelphus squarrosus is occasion-al and Calliergon stramineum and Aulacomniumpalustre are patchy throughout. Calliergon cuspi-datum and Plagiothecium undulatum are conspic-uously rare.
This mire is the major soligenous communityof peats and peaty gleys irrigated by rather base-poor waters in the sub-montane zone of northernand western Britain. The soils and water are quiteacidic with a superficial pH usually between 4.5and 5. It typically occurs as small stands amongother mire communities, grassland and heaths andsometimes with swamp and spring vegetation. It iscommonly found in tracts of unenclosed pastureon upland fringes, particularly between 200 m and400 m (although it may be found much higher)and is ubiquitous in the upland fringes of Britain. The community is frequently grazed. This, espe-cially where combined with drainage, can convertthe community to grassland. The exclusion of her-bivores would be expected to permit progress towet scrub and woodland, although in many casesthis would probably be slow and patchy.
24
M6 Carex echinata – Sphagnumrecurvum/auriculatum mire
25
Mix
ture
s of
Car
exec
hin
ata,
C. n
igra
an
d
C. p
anic
ea u
sual
ly d
omi-
nat
e w
ith
Eri
oph
oru
man
gust
ifol
ium
som
etim
esab
un
dan
t bu
t Ju
ncu
s sp
p.
at m
ost
spar
se.
Sed
ge c
over
les
s va
ried
an
d e
xten
sive
and
Eri
opho
rum
an
gust
ifol
ium
usu
ally
spar
se;J
uncu
s ef
fusu
sor
J. a
cuti
flor
us
dom
inan
t.
Car
ex n
igra
,C
. pan
icea
an
d
C. e
chin
ata
equ
ally
freq
uen
t an
d
mix
ture
s of
th
ese
usu
ally
dom
inat
e.
Nar
du
s st
rict
a an
d
Jun
cus
squ
arro
sus
very
com
mon
amon
g a
som
etim
esp
atch
y S
ph
agn
um
cove
r.
Jun
cus
effu
sus
isth
e m
ost
abu
nd
ant
rush
am
ong
anex
ten
sive
Sp
hag
nu
m c
arp
etu
sual
ly d
omin
ated
by S
. rec
urv
um
wit
h S
. pal
ust
re.
Jun
cus
acu
tifl
oru
s u
sual
ly t
otal
lyre
pla
cin
g J.
eff
usu
sw
ith
Mol
inia
caer
ule
a fr
equ
ent
and
a g
ener
ally
mor
e va
ried
S
ph
agn
um
car
pet
.
M6a
Ca
rex
ech
ina
tasu
b-co
mm
un
ity
Th
e ve
geta
tion
is
gen
eral
ly d
omin
ated
by
mix
ture
s of
sed
ges
wit
h C
arex
ech
ina-
ta g
ener
ally
mos
t co
mm
on; g
rass
es a
rera
ther
sca
rce
exce
pt
for
Mol
inia
cae
rule
aan
d A
gros
tis
can
ina
ssp
. can
ina
wh
ich
are
very
com
mon
. Eri
oph
oru
m a
ngu
sti-
foli
um
is
freq
uen
t an
d m
ay d
omin
ate.
Ru
shes
are
typ
ical
ly s
carc
e an
d o
f lo
wco
ver.
Th
e S
ph
agn
um
car
pet
is
typ
ical
lyex
ten
sive
an
d l
uxu
rian
t. S
. pal
ust
re i
sco
mm
on b
ut
S. r
ecu
rvu
man
d S
. au
ricu
la-
tum
sh
ow a
pat
tern
of
rep
lace
men
t, t
he
latt
er b
ecom
ing
mor
e p
rom
inen
t in
th
eoc
ean
ic f
ar w
est
of B
rita
in. D
rose
ra
rotu
nd
ifol
ia, N
arth
eciu
m o
ssif
ragu
m,
Eri
ca t
etra
lix,
Jun
cus
bulb
osu
s/ko
chii
an
dM
enya
nth
es t
rifo
liat
a sh
ow s
ome
pre
fer-
ence
for
th
e S
. au
ricu
latu
m t
ype
of f
lush
.
Th
is s
ub-
com
mu
nit
y is
fou
nd
th
rou
ghou
tth
e ra
nge
of
M6.
Two
vari
ants
.
M6b
Ca
rex
nig
ra–
Na
rdu
s st
rict
asu
b-co
mm
un
ity
Toge
ther
wit
h t
he
Car
ex s
pp
. an
d o
ther
spec
ies
men
tion
ed a
bove
, Eri
oph
oru
man
gust
ifol
ium
is v
ery
com
mon
an
dA
nth
oxan
thu
m o
dor
atu
m f
requ
ent.
Jun
cus
squ
arro
sus
is a
goo
d p
refe
ren
tial
,bu
t J.
eff
usu
s is
sca
rce
and
J. a
cuti
flor
us
abse
nt.
In
som
e st
and
s S
ph
agn
um
recu
rvu
m a
nd
S. p
alu
stre
are
th
e co
mm
ones
t S
ph
agn
um
sp
ecie
s w
ith
poo
rfe
n h
erbs
su
ch R
anu
ncu
lus
flam
mu
la,
Ep
ilob
ium
pal
ust
re a
nd
Cir
siu
m p
alu
stre
.In
con
tras
t ot
her
sta
nd
s h
ave
a gr
eate
rab
un
dan
ce o
f S
ph
agn
um
sp
p.,
wit
h
S. a
uri
cula
tum
,S. s
ubn
iten
s an
d S
. p
apil
losu
m b
ein
g p
refe
ren
tial
an
d o
ften
som
e M
olin
ia c
aeru
lea
pre
sen
t am
ong
the
oth
er g
rass
es.
Th
is s
ub-
com
mu
nit
y is
fou
nd
th
rou
ghou
tth
e ra
nge
of
M6.
Two
vari
ants
.
M6c
Jun
cus
effu
sus
sub-
com
mu
nit
y
Sed
ges
are
less
fre
quen
t an
d a
bun
dan
tan
d t
he
vege
tati
on i
s d
omin
ated
by
Jun
cus
effu
sus.
Fre
quen
t va
scu
lar
asso
ciat
es a
re f
ew b
ut
ther
e is
oft
en s
ome
Agr
osti
s ca
nin
a ss
p. c
anin
a,P
oten
till
aer
ecta
, an
d (
rath
er d
iagn
osti
c h
ere)
G
aliu
m s
axat
ile.
Car
ex e
chin
ata,
Mol
inia
caer
ule
a an
d V
iola
pal
ust
ris
are
also
fa
irly
com
mon
. Th
e S
ph
agn
um
car
pet
is
gen
eral
ly e
xten
sive
an
d l
uxu
rian
t an
d
S. r
ecu
rvu
mis
alm
ost
alw
ays
dom
inan
t.
Pol
ytri
chu
m c
omm
un
e re
mai
ns
freq
uen
tan
d s
omet
imes
abu
nd
ant.
Th
is s
ub-
com
mu
nit
y is
fou
nd
th
rou
ghou
tth
e ra
nge
of
M6.
Two
vari
ants
.
M6d
Jun
cus
acu
tifl
oru
ssu
b-co
mm
un
ity
Jun
cus
acu
tifl
oru
s is
dom
inan
t ov
er a
nex
ten
sive
Sp
hag
nu
m c
arp
et a
nd
Mol
inia
caer
ule
a be
com
es m
ore
con
sist
entl
y fr
equ
ent.
Mos
t of
th
e sa
me
poo
r-fe
n h
erbs
as l
iste
d i
n M
6c a
re f
requ
ent.
Sp
hag
nu
msp
p. a
re g
ener
ally
abu
nd
ant
wit
h
S. p
alu
stre
com
mon
th
rou
ghou
t an
d
S. r
ecu
rvu
m o
r S
. au
ricu
latu
m w
ith
S. s
ubn
iten
s,S
. pap
illo
sum
an
d S
. cap
illi
-fo
liu
m h
avin
g d
omin
ance
in
th
e ca
rpet
.
Th
is s
ub-
com
mu
nit
y is
fou
nd
th
rou
ghou
tth
e ra
nge
of
M6.
Two
vari
ants
.
Car
ex e
chin
ata
usu
ally
th
e m
ost
abu
nd
ant
sed
ge,
C. p
anic
ea a
nd
C
. nig
ra s
ubo
rdi-
nat
ean
d N
ard
us
stri
cta
and
Ju
ncu
ssq
uar
rosu
s oc
ca-
sion
al i
n a
n e
xten
-si
ve S
phag
num
carp
et.
M6
This mire community has prominent cyperaceousand Sphagnum components with a distinct north-ern and montane character. Eriophorum angusti-folium and Carex echinata are very frequent andprovide a floristic link with the Carex echinata –Sphagnum recurvum/auriculatum mire (M6) com-munity which occurs at lower altitudes, but incontrast, C. curta is a constant often with highcover. It is often accompanied by C. bigelowii or C. aquatilis and C. rariflora. Carex nigra can alsooccur, sometimes abundantly. Larger Juncus spp.,e.g. Juncus effusus and J. acutiflorus, are veryscarce, again in contrast to M6.
The Sphagnum carpet is typically extensive.Sphagnum papillosum is common and oftenabundant, and S. subnitens, S. auriculatum,S. capillifolium or S. recurvum may be frequent.The high altitude species S. russowii is constant asis S. lindbergii in one of the sub-communities.The rare S. riparium also grows in this community.Other frequent bryophytes are Polytrichum com-
mune, Calliergon stramineum or C. sarmentosum.Grasses play a minor role, although Nardus strictais very common and Agrostis canina ssp. caninafrequent. Among dicotyledons Viola palustris andGalium saxatile are most common, but are typi-cally of low cover.
This community is confined to high altitudesites, usually above 650 m, forming small standswhere peaty soils are irrigated by oligotrophic and base-poor waters. It is characteristic of hollowsand drainage channels in blanket mires or flushesand seepage areas in tracts of montane mossheaths. It is an altitudinal replacement for Carex echinata – Sphagnum recurvum/auriculatummire (M6) with a preponderance of montaneplants. The community is mainly confined to thecentral Highlands of Scotland, but extends southinto the Pennines and perhaps also into Wales.
Most of the occurrences of the Carex curta –Sphagnum russowii mire are close to or above thepotential forest limit in the Scottish Highlandsand the community is probably an essentially sta-ble component of the vegetation pattern underpresent-day conditions.
26
M7 Carex curta – Sphagnum russowii mire
M7
Sphagnum lindbergii absent with S. recurvum abundant among frequent S. papillosum and S. russowii. Carex bigelowii veryscarce and C. echinata usuallydominant.
M7a
Carex bigelowii – Sphagnum lindbergii sub-community
Carex curta can be common with C. echinata and C.bigelowii but other sedges are scarce. Among the fewdicotyledons Saxifraga stellaris is preferential. As well asthe Sphagnum spp. mentioned above, S. subnitens, S. auric-ulatum and S. capillifolium are frequent and S. recurvumscarce. Among other bryophytes Polytrichum commune isfrequent, but more distinctive are Calliergon sarmentosum,Drepanocladus exannulatus, Polytrichum alpestre and P. alpinum.
This sub-community is found throughout the range of M7.
Sphagnum lindbergii very frequent and usually co-domi-nant with S. papillosum.Carexechinata usually co-dominantwith C. bigelowii in the vasculartier with Nardus stricta common.
M7b
Carex aquatilis – Sphagnum recurvum sub-community
Carex curta is often co-dominant with C. echinata. Somestands have the rare C. aquatilis and C. rariflora. C. nigrais more common in this sub-community and can be locallydominant. There is also more diversity among vascular associates with Festuca vivipara, Agrostis stolonifera,Deschampsia flexuosa, Luzula multiflora and Galium sax-atile all preferential. Nardus stricta is only occasional. Onlythe Sphagnum spp. mentioned above are frequent. Otherbryophytes are few, but Polytrichum commune is better represented and Calliergon stramineum replaces C. sarmentosum.
This sub-community is more local being concentratedaround the Clova-Caenlochan area of the east Highlands.
M8 Carex rostrata – Sphagnumwarnstorfii mireThis community has a dominant cover of sedgesover an extensive carpet of Sphagnum spp. and afairly numerous and diverse assemblage of herbs.Carex rostrata and C. nigra are the commonestsedges, the former usually more abundant and ofhigh cover. Other poor-fen sedges, C. panicea,C. echinata and C. demissa occur frequently and sometimes abundantly and C. pulicaris isoccasional.
The Sphagnum carpet is typically extensive,and the prominence of the base-tolerantSphagnum teres and S. warnstorfii is quite dis-tinctive. Sphagnum recurvum occurs frequentlyand S. subsecundum sensu stricto, although onlyoccurring occasionally, is also very characteristicof this community.
Other bryophytes are numerous and in particu-lar Aulacomnium palustre and Rhizomniumpseudopunctatum are frequent. Also distinctiveare Calliergon cuspidatum, C. stramineum andless frequently C. sarmentosum. Homalotheciumnitens is quite common and a good diagnosticspecies. Hylocomium splendens and Rhytidiad-elphus squarrosus are frequently recorded.
Herbaceous associates are common but typicallyof low total cover. Constant species are Epilobiumpalustre, Potentilla erecta, Viola palustris and
Selaginella selaginoides. Common grasses areFestuca ovina (and F. vivipara), Nardus stricta,Anthoxanthum odoratum and Agrostis stolonifera,all of which are generally present as scatteredshoots or small tussocks.
This community typically occurs as smallstands and is strictly confined to raw peat soils in waterlogged hollows in the montane zone ofBritain where there is moderate base-enrichmentby drainage from calcareous rocks. These condi-tions are not common. The peat deposits on whichthe community is found are typically quite deep,usually more than 1 m, with a high and stagnantwater table. The pH of the waters and the peat isusually between 5.5 and 6. The small but distinctmontane element in the flora of this communityhelps separate it from the Carex rostrata –Sphagnum squarrosum mire (M5) which is foundin analogous situations in the lowlands. The com-munity is generally confined to altitudes between400 m and 800 m in the central Highlands exceptfor a few examples in southern Scotland andnorthern England.
The frequent presence of seedlings of Salixaurita in stands of the community may indicate a tendency towards the development of montanewillow scrub but such successions have neverbeen seen to progress further.
No sub-communities.
27
This community has a diverse composition andphysiognomy, even within individual stands, butis generally characterised by a fairly rich assemblage of sedges and vascular plants over acarpet of bulky mosses and localised patches ofSphagnum spp. The commonest large sedge isCarex rostrata, which is often abundant and sometimes dominant. Carex diandra is frequent,and C. lasiocarpa may accompany one or both ofthese species. Carex paniculata or C. appropin-quata is present in some localities. Small sedgeswhich commonly occur in this communityinclude C. panicea and C. nigra.
Intermixed with these species, or fringingpatches of them, are a variety of associates.Potentilla palustris and Menyanthes trifoliata arecommon and are particularly important when the vegetation forms floating rafts. Also common areEriophorum angustifolium, Equisetum fluviatile,E. palustre, Succisa pratensis, Pedicularis palustris, Cirsium palustre and Ranunculus flammula often with Galium palustre. Less evenly distributed and usually present as scattered individuals are Mentha aquatica, Calthapalustris, Valeriana dioica, Angelica sylvestris,Epilobium palustre and Lychnis flos-cuculi. Thecommonest grass to occur in this community isMolinia caerulea, particularly in drier stands.
Bryophytes are almost always conspicuous.Calliergon cuspidatum is constant and C. gigan-teum and C. cordifolium frequent. One or more of
the larger Mniaceae are also common. Campyliumstellatum is a distinctive species of this communi-ty together with Scorpidium scorpioides andDrepanocladus revolvens.
This community is characteristic of soft,spongy peats kept permanently moist by at least moderately base-rich and calcareous waters.Waters and substrates always have a pH above 5and usually above 6. It is commonest in wetterparts of topogenous mires in hollows or old peat-workings, but also around springs, laggs of raisedmires and mowing marshes. The community iswidespread but local, ranging from south-eastEngland, particularly in Broadland, to Wales andnorthern England and through most of Scotland.
The community is limited by the fairly sparseoccurrence of suitable natural situations and inthe lowland south-east by wetland drainage andthe cessation of shallow peat-digging. It is typically too wet to be grazed but in some areas itoccurs within mowing marsh that is periodicallycropped. Throughout its range, at least at thelower altitudes and in less remote sites, the Carexrostrata – Calliergon cuspidatum/giganteum mireis probably a successional stage to Salix pentan-dra – Carex rostrata woodland (W3) in the northand Salix cinerea – Betula pubescens – Phragmitesaustralis woodland (W2) in the south-east,although development to woodland may be hin-dered by a high water table or by the periodicmowing of the vegetation. There is also the possi-bility that under certain conditions this mire typeis seral to the development of poor-fen andombrogenous mire through the local formation ofSphagnum nuclei.
28
M9 Carex rostrata – Calliergon cuspidatum/giganteum mire
29
M9
Car
ex r
ostr
ata
and
C. d
ian
dra
co
nst
ant,
eit
her
or
both
dom
inan
tw
ith
or
wit
hou
t C
. las
ioca
rpa.
Her
bace
ous
asso
ciat
es o
ften
n
um
erou
s an
d l
ush
. Cam
pyl
ium
stel
latu
m o
nly
occ
asio
nal
an
dS
corp
idiu
m s
corp
ioid
es a
nd
D
rep
anoc
lad
us
revo
lven
s ra
re,
but
Cal
lier
gon
cor
dif
oliu
m a
nd
C
. gig
ante
um
com
mon
, oft
en
wit
h l
arge
Mn
iace
ae.
M9a
Ca
mp
yliu
m s
tell
atu
m–
Sco
rpid
ium
sco
rpio
ides
sub-
com
mu
nit
y
Sm
alle
r se
dge
s ar
e m
ore
nu
mer
ous
than
in
M9b
; Car
ex p
an-
icea
and
C. n
igra
ret
ain
th
eir
hig
h f
requ
ency
an
d C
. lim
osa
and
C. e
chin
ata
are
stro
ngl
y p
refe
ren
tial
. Her
bace
ous
asso
ci-
ates
are
var
iabl
e an
d n
ot v
ery
rich
, an
d t
otal
cov
er i
s lo
w,
givi
ng
an o
pen
com
mu
nit
y. M
enya
nth
es t
rifo
liat
a an
dP
oten
till
a p
alu
stri
s ca
n b
e p
rom
inen
t, b
ut
mos
t sp
ecie
soc
cur
as s
catt
ered
pla
nts
. Bry
oph
ytes
are
usu
ally
pro
min
ent
as i
nd
icat
ed a
bove
. Clu
mp
s of
Sp
hag
nu
m s
pp
. are
occ
asio
n-
al, n
otab
ly s
o fo
r th
e ba
se-t
oler
ant
Sp
hag
nu
m c
onto
rtu
m.
Th
is s
ub-
com
mu
nit
y is
lar
gely
nor
th-w
este
rn i
n r
ange
.
Car
ex r
ostr
ata
usu
ally
dom
inan
t,so
met
imes
wit
h C
. las
ioca
rpa
orm
ore
loca
lly
C. d
ian
dra
or
Sch
oen
us
nig
rica
ns.
Cal
lier
gon
cu
spid
atu
m c
omm
on b
ut
oth
erC
alli
ergo
n s
pec
ies
and
lar
ger
Mn
iace
aeat
mos
t lo
cal.
Gro
un
d
carp
et u
sual
ly d
omin
ated
by
mix
ture
s of
Cam
pyl
ium
ste
llat
um
,S
corp
idiu
m s
corp
ioid
es a
nd
Dre
pan
ocla
du
s re
volv
ens.
M9b
Ca
rex
dia
nd
ra–
Ca
llie
rgon
gig
an
teu
msu
b-co
mm
un
ity
Th
e p
atte
rn o
f d
omin
ance
is
mor
e va
riab
le h
ere
as i
nd
icat
edab
ove.
Ju
ncu
s su
bnod
ulo
sus
is l
ocal
ly a
bun
dan
t in
eas
tern
En
glan
d. H
erba
ceou
s as
soci
ates
are
mor
e n
um
erou
s;
Pot
enti
lla
pal
ust
ris,
Men
yan
thes
tri
foli
ata
and
Fil
ipen
du
lau
lmar
ia c
an b
e p
rom
inen
t w
ith
An
geli
ca s
ylve
stri
s,E
pil
obiu
m p
alu
stre
,Lyc
hn
is f
los-
cucu
li,V
aler
ian
a d
ioic
a,C
alth
a p
alu
stri
s,C
ard
amin
e p
rate
nsi
s an
d M
enth
a aq
uat
ica
all
freq
uen
t. B
ryop
hyt
es a
re o
ften
ext
ensi
ve w
ith
Cal
lier
gon
giga
nte
um
,C. c
ord
ifol
ium
,Pla
giom
niu
m r
ostr
atu
m a
nd
P.
aff
ine
show
ing
thei
r m
axim
um
dev
elop
men
t in
th
is
sub-
com
mu
nit
y.
Th
is s
ub-
com
mu
nit
y oc
curs
th
rou
ghou
t th
e ra
nge
mos
tly
into
pog
enou
s m
ires
.
30
The community includes a range of distinctivecalcicolous flush vegetation in which the bulk ofthe sward is composed of small sedges, dicotyle-dons and bryophytes. There are marked variationsin proportions of frequent species, as indicated inthe three sub-communities and their variants.Essentially this is a small sedge mire with Carexdioica, C. hostiana, C. lepidocarpa, C. panicea andC. pulicaris as constants which are also oftenabundant. Carex nigra is frequent and C. echinataand C. flacca common. Other prominent Cyper-aceae are Eriophorum angustifolium, a constant,and Eleocharis quinqueflora.
Some rushes and grasses occur frequently.Juncus articulatus is a constant and J. bulbosus/kochii is typical of less base-rich sites. Moliniacaerulea is the commonest grass with Festucaovina more variable in occurrence. Other herbsgenerally occur as scattered plants. The frequentoccurrences of Pinguicula vulgaris and Selaginellaselaginoides are very distinctive of this communi-ty. Potentilla erecta and Succisa pratensis are also common species in this community butEquisetum palustre and Euphrasia officinalis agg.are more variable in occurrence. Other species arecharacteristic of particular sub-communities.
Bryophytes are always obvious, often compris-ing 50% or more of the ground cover. Calcicolousspecies such as Campylium stellatum, Aneurapinguis, Drepanocladus revolvens, Ctenidiummolluscum, Fissidens adianthoides and Craton-euron commutatum are frequent, together withBryum pseudotriquetrum. Such assemblages of
calcicolous species provide a strong definition forthe community against its counterparts in theCaricion nigrae (M5-M7) and in flushed Oxycocco– Sphagnetea mires (M14-M21) which occupysimilar but more base-poor situations.
This community is typically a soligenous mireof mineral soils and shallow peats kept very wetby base-rich, calcareous and oligotrophic waters.The pH of flushing waters is high, usuallybetween 5.5 and 7.0 or sometimes higher, and thecomposition of this community is one of the mostcalcicolous of British mires. It is found in smallstands, often associated with spring and rill vegetation, within grasslands and more occasion-ally in ombrogenous mires and around topoge-nous mires. Typically the in situ formation of peatis limited, a feature which helps to distinguish thehabitat of the community from that of base-richbasins where it is replaced by vegetation like theCarex rostrata – Calliergon cuspidatum/giganteummire (M9) and the Carex rostrata – Sphagnumwarnstorfii mire (M8). It is predominantly a com-munity of north-west Britain from Wales and thePennines northwards, developed in the cool, wetclimate.
The community typically occurs in unencloseduplands and most of the stands are grazed andtrampled by large herbivores. It is probably thesefactors, combined with nutrient impoverishmentand the often strong and scouring effect of the irrigation, which play a major part in maintainingthe community in its generally rich, varied andopen state. Most stands would probably progressto Alno – Ulmion scrub or woodland (W7, W9) ifgrazing were withdrawn. However, at higher altitudes the vegetation may be a climatic climax.
M10 Carex dioica – Pinguiculavulgaris mire
31
M10
Species listed opposite scarce or absent. Gymnostomum recurvirostrum or less commonly Catascopium nigritum forminghummocks with Drepanocladusrevolvens and Cratoneuron commutatum often abundant.
Carex hostiana, C. pulicaris and C. nigra all frequent with Eriophorum angustifolium and Molinia caerulea. Potentilla erecta and Succisa pratensiscommon with Ctenidium molluscum and Fissidens adianthoides frequent.
M10c
Gymnostomum recurvirostrumsub-community
Vascular plants have low individual and total cover;much more prominent are theconspicuous moss hummocks,particularly of Gymnostomumrecurvirostrum which are up to30 cm high and 60 cm across.There is much bare ground witha fragmentary cover of vascularplants; good preferentials are Plantago maritima, Saginanodosa and Minuartia verna.M. stricta is restricted to thissub-community in its onlyBritish locus.
This striking vegetation is onlyrecorded from Upper Teesdale.
Carex demissa and C. echinata occasionalto frequent; C. lepido-carpa and C. flaccascarce and C. pulicarispatchy. Juncus bulbo-sus and Erica tetralixquite common.
Carex demissa and C. echinata scarce, but C. lepidocarpa,C. hostiana, C. pulicarisand C. flacca frequent. Juncus bulbosus and Erica tetralix only oflocal significance.
M10a
Carex demissa – Juncus bulbosus/kochii sub-community
This comprises the less calcicolous types of M10 withvascular plants predominant. Carex panicea, C. dioica,C. hostiana and C. nigra remainvery frequent with the specieslisted above. More calcicolousherbs such as Briza media,Primula farinosa, Linum catharticum and Sesleria albicans are usually poorly represented. Bryophytes aregenerally less prominent in theturf; Bryum pseudotriquetrum,Fissidens adianthoides and Ctenidium molluscum arerather uncommon and Campylium stellatum and Scorpidium scorpioidesrather more prominent.
This sub-community is largelyrestricted to Scotland and theLake District with outlyingoccurrences in north-westWales and Upper Teesdale.
Three variants.
M10b
Briza media – Primula farinosa sub-community
Vascular plants are also prominent but many swards are open with extensive bareground. Calcicoles and moremesophytic herbs well represented. Carex lepidocarpa,C. hostiana and C. pulicaris areconsistently frequent and com-monly accompanied by C. flac-ca. Among the preferentialsBriza media, Primula farinosa,Linum catharticum, Sesleriaalbicans and Equisetum variegatumare frequent. Juncus bulbosus/ kochii, Erica tetralix,Narthecium ossifragum andDrosera rotundifolia arereduced in their occurrence.Among the bryophytes Aneurapinguis, Ctenidium molluscumand Fissidens adianthoides areconsistently frequent.
This sub-community is predominantly found in northern England.
Three variants.
32
This vegetation is typically open with rich mix-tures of small sedges, other herbs and bryophytesamong water-scoured runnels and with muchexposed silt and rock debris. There is a strongfloristic link with Carex dioica – Pinguicula vul-garis mire (M10) but the Arctic-Alpine element ofthe vegetation is much more pronounced in thiscommunity than it is in M10. Typically there is nosingle dominant. Carex demissa, C. panicea andC. pulicaris are very frequent throughout and C. flacca and C. dioica are common in some vari-ants. Juncus articulatus is a constant, Eriophorum angustifolium is frequent as is Eleocharis quin-queflora at lower altitudes. At higher altitudesJuncus triglumis is constant and Tofieldia pusillabecomes frequent. By comparison with M10, C. lepidocarpa and C. hostiana are much less com-mon and C. nigra and C. echinata also ratherscarce. At higher altitudes there is an Arctic-Alpine element with Juncus triglumis being con-stant and Tofieldia pusilla becoming more fre-quent. Grasses are typically low in cover. Festucaovina/vivipara is common and Agrostis stoloniferaoccasional. At higher altitudes Deschampsiacespitosa (including D. alpina), Nardus stricta,Anthoxanthum odoratum, Agrostis canina ssp.canina and Festuca rubra may be present.
Other herbs found in this community includePinguicula vulgaris and Saxifraga aizoides whichare both constant and Selaginella selaginoideswhich is very frequent. The montane element of thiscommunity includes Thalictrum alpinum, which is
very common at higher altitudes, and occasionallySaxifraga stellaris, S. oppositifolia and Alchemillafilicaulis ssp. filicaulis. Typically all these speciesoccur in an uneven and broken sward.
Bryophytes are frequent and varied. Aneura pinguis, Campylium stellatum, Drepanocladusrevolvens, Bryum pseudotriquetrum, and at loweraltitudes, Cratoneuron commutatum, Fissidensadianthoides, Ctenidium molluscum and Scor-pidium scorpioides are all common. The montanemoss Blindia acuta can be prominent at higheraltitudes and is a good preferential for this com-munity.
This community is characteristic of open,stony flushes, strongly irrigated with moderately base-rich waters, on generally steep slopes in sub-montane and montane parts of Britain. Althoughthe community can occur almost at sea level in thefar north-west of Scotland, it is generally confinedto high altitudes. It is always associated with cal-careous bedrocks having a soil pH range of 5.5 to7.0. Flushing is vigorous and erosion of the sur-face is therefore often pronounced and the soilcover little more than scoured accumulations ofsilt and organic matter with exposed rock debris.It is largely confined to Scotland, but also presentin the Lake District, and more locally in theSouthern Uplands, the northern Pennines andnorth Wales.
The community is normally grazed and this grazing may help maintain the open structure andhelp prevent the development of a woody cover.However, colonisation of trees and scrubs wouldbe slow due to the climatic conditions in whichthe community occurs and at higher altitudes themire is probably a climatic climax.
M11 Carex demissa – Saxifragaaizoides mire
M11
Eleocharis quinqueflora constant with Juncus triglumisand Thalictrum alpinum becoming more frequent at higheraltitudes. The grasses found in M11a at most occasional.Cratoneuron commutatum and Scorpidium scorpioides verycommon and abundant, often with Fissidens adianthoides.
Juncus triglumis and Thalictrum alpinum constant, but Eleocharis quinqueflora uncommon. Deschampsia cespitosa, Nardus stricta and Anthoxanthum odoratum frequent and Alchemilla alpina occasional. Cratoneuroncommutatum, Scorpidium scorpioides and Fissidens adianthoides all scarce.
M11bCratoneuron commutatum – Eleocharis quinqueflorasub-community
In this sub-community M11 grades into M10 with moreextreme montane plants, except Saxifraga aizoides andBlindia acuta, much more poorly represented; and in moresoutherly stands even these become rare. Eleocharis quin-queflora is constant and sometimes abundant, rivalling thesedges, among which Carex hostiana and, in wetter stands,C. rostrata are sometimes found. Vascular plant cover typically more extensive than in M11a.
This sub-community is also frequent in Scotland at loweraltitudes and in most of the English and Welsh stands.
M11aThalictrum alpinum – Juncus triglumis sub-community
There is an obvious montane element in the vegetation asindicated in the species above. Saxifraga aizoides, Carexdemissa and C. panicea are usually the most abundant vascular plants with Blindia acuta, Campylium stellatum orDrepanocladus revolvens predominating among the mosses.
This is the typical form of M11 at higher altitudes and is virtually confined to Scotland.
Two variants.
33
Carex saxatilis is typically dominant in this montane mire with a distinctive assemblage ofassociates. The sward is generally less than 20 cmhigh and rather open with patches of soil. Carexdemissa, C. echinata and C. nigra are very fre-quent and can be abundant. Carex bigelowii is fair-ly consistent, especially in grassy transitions tosurrounding swards.
Eriophorum angustifolium is also frequent attaining a cover of more than 10%. Almost allother herbs occur as scattered individuals.Selaginella selaginoides and Pinguicula vulgarisare both very common as in other calcicolousflushes, but more distinctive are Thalictrumalpinum, Polygonum viviparum, and Juncus trig-lumis. Saxifraga aizoides is infrequent, in contrastto Carex demissa – Saxifraga aizoides mire (M11).Also common are the poor-fen herbs Viola palus-tris, Caltha palustris and Agrostis canina ssp. canina.
Bryophytes are an important element of the vegetation although apart from the constantDrepanocladus revolvens, cover of individualspecies is low. Aneura pinguis is frequent andBryum pseudotriquetrum, Blindia acuta, Campy-lium stellatum and Calliergon trifarium are occa-
sional. Hylocomium splendens is also a constantas is Scapania undulata. There can also be somesmall patches of Sphagnum spp.
This mire type is strictly confined to margins ofhigh-montane flushes irrigated with base-rich andcalcareous waters perhaps influenced by longsnow-lie. It typically occurs as small stands bor-dering rills or more strongly irrigated soligenousmires. The soils that this community is found on,though continuously irrigated, are not of especial-ly high pH, ranging from 4.6 to 6.3. The commu-nity is fairly widespread but local on peaks above750 m through the southern and central ScottishHighlands with scattered localities in north-westScotland.
The physical effects of flushing, snow-melt, cryoturbation, and solifluctional flow result in thecontinual instability of the substrate on which thiscommunity is found and this is important inmaintaining open stony areas where rare Arctic-Alpine sedges and rushes find a niche. It ispossible that grazing prevents colonisation byArctic-Alpine willows; however, in the extremeenvironment in which it occurs the community isprobably a climatic climax.
No sub-communities.
M12 Carex saxatilis mire
frequently the constant Potentilla erecta and Ericatetralix.
Bryophytes vary in cover and species but canbe very extensive. The commonest throughout areCampylium stellatum and Calliergon cuspidatum.Other frequent species include Drepanocladusrevolvens, Aneura pinguis, Cratoneuron commu-tatum and C. filicinum.
This community is confined to peat or mineralsoils, in and around lowland mires irrigated bybase-rich, highly calcareous, and oligotrophicwaters. It is often found below springs and seep-age lines and on flushed margins of valley mires,but also extends into topogenous basins providedthere is close contact with waters draining fromlime-rich substrates. The flushing waters typicallyhave pH between 6.5 and 8. It is widespread butlocal throughout lowland England and Wales, butis restricted by natural scarcity of suitable habitatand its extensive destruction.
The structure and floristics of this communityare often influenced by grazing and some standshave been affected by mowing and burning.Shallow peat-digging has been locally importantin providing a suitable habitat for the communitybut more drastic treatment of mires, particularlydraining and eutrophication, have reduced itsextent and eliminated it from some areas.
34
In this community Schoenus nigricans is typicallyvery frequent and consistently associated withother distinctive floristic features. It is generallydominant (although it may be absent from frag-mentary stands) giving a grey-green appearance tothe vegetation. Commonly it is intermixed withJuncus subnodulosus, and where this predomi-nates the vegetation is olive-green in spring andreddish brown in winter. Molinia caerulea is alsoconstant. These species form a rough sward about50 cm in height with smaller herbs growing in-between. Sedges are often important, particularlyCarex panicea, C. lepidocarpa and C. flacca.Where the summer water table is close to the surface, species such as Equisetum palustre,Pedicularis palustris, Mentha aquatica, Valerianadioica and Cardamine pratensis occur, sometimeswith Parnassia palustris, Pinguicula vulgaris andEriophorum latifolium. A variety of orchids arefound, particularly Epipactis palustris. Tallerherbs can be locally abundant with Succisapratensis being most common. Phragmites australisis also frequent, particularly in ungrazed stands.On drier areas and particularly tops of Schoenustussocks less calcicolous plants are found, most
M13 Schoenus nigricans – Juncussubnodulosus mire
35
Carex hostiana and C. pulicaris very frequent among an abundant and diversesmall herb flora in runnels with Brizamedia, Pinguicula vulgaris, Linumcatharticum, and Juncus articulatus com-mon.
M13bBriza media – Pinguicula vulgaris sub-community
This kind of Schoenetum is strikinglyrich. Mixtures of Schoenus nigricans,Juncus subnodulosus and Moliniacaerulea usually share dominance butthe small herbs of runnels are especiallydistinctive. Apart from the species men-tioned above, Parnassia palustris is fre-quent often with mixtures of orchidsincluding Gymnadenia conopsea var.densiflora, Dactylorhiza fuchsii,D. majalis ssp. purpurella and Epipactispalustris. Along with Succisa pratensisand Serratula tinctoria, taller herbs arerepresented by frequent Angelicasylvestris, Cirsium palustre, Eupatoriumcannabinum and Oenanthe lachenalii.Bryophytes are quite numerous andsometimes of high cover.
This sub-community occurs in Angleseyand East Anglia.
M13cCaltha palustris – Galium uliginosumsub-communitySchoenus nigricans, Juncus subnodulo-sus and Molinia caerulea remain ofstructural importance but are variouslyaugmented by Carex rostrata, C. diandra,C. elata, Cladium mariscus and some-times Phragmites australis. Runnels arewell developed but smaller preferentialsof M13b are only occasional. The com-monest species are Carex panicea, C. lep-idocarpa, Mentha aquatica, Hydrocotylevulgaris together with the preferentialsCaltha palustris and Valeriana dioica. Inaddition to Epipactis palustris there isoften Dactylorhiza incarnata, D. majalisssp. praetermissa and sometimes D. traunsteineri. Taller herbs are common, as listed above, with sprawlingGalium uliginosum and less commonlyG. palustre. A pool element is sometimespresent, with Carex rostrata and C. dian-dra together with Menyanthes trifoliata,Equisetum fluviatile and Utriculariaspecies.
This sub-community is concentrated inEast Anglia.
M13
Juncus subnodulosus and Moliniacaerulea often very abundant with Schoenus nigricans markedlyreduced in vigour. Festuca rubra,Holcus lanatus, Agrostis canina and A. stolonifera frequent and tallherbs, orchids and bryophytespatchy.
M13aFestuca rubra – Juncus acutiflorussub-community
This comprises the more impover-ished stands of M13. Apart fromthe reduction or even absence ofSchoenus nigricans and presenceof the species mentioned above,Carex panicea, C. lepidocarpa, andC. flacca are also important in run-nels. Anagallis tenella is totallyabsent and Pedicularis palustris,Epipactis palustris and otherorchids are very scarce. The com-monest herbs are Succisa pratensisand Hydrocotyle vulgaris.Bryophytes are generally sparseand low in number with Calliergoncuspidatum the commonestspecies.
This sub-community occursthrough the range of M13.
Many smaller runnel herbs sporadic, butCaltha palustris and Valeriana dioicabecome common and taller dicotyledonsare often prominent with Filipendulaulmaria, Eupatorium cannabinum andLychnis flos-cuculi frequent.
General floristic and structural features well preserved, with at leastsome of Anagallis tenella, Pedicularis palustris, Angelica sylvestris,Cirsium palustre, Mentha aquatica, Equisetum palustre and Phragmitesaustralis frequent.
36
This is a vegetation type with few constants and awide variation in the pattern of dominance and in associated flora. Molinia caerulea, Scirpus cespitosus, Erica tetralix and Calluna vulgaris areall of high frequency and it is mixtures of thesespecies that give the vegetation its general character. However, sometimes one or two of themmay be missing and their relative proportions arevery diverse. Molinia is the most consistent over-all and often abundant; in other stands Scirpus isvery prominent and both may share dominancewith Calluna. Molinia may also dominate withScirpus or with Erica tetralix. The shrubby speciesErica cinerea, Vaccinium myrtillus and Myricagale are important in particular sub-communities.Other common species are Potentilla erecta, and in moister stands, Polygala serpyllifolia,Narthecium ossifragum and Eriophorum angusti-folium. By contrast E. vaginatum is notably scarce.
There are few bryophytes common throughout.There are usually some Sphagnum spp. but theydo not form the luxuriant carpets of theSphagnetalia mires (M17-M21). The most frequentspecies overall are Sphagnum capillifolium and S. subnitens. Sphagnum palustre, S. recurvumand S. auriculatum can become common in wetterstands. Lichens do not appear consistently butCladonia spp. can be locally prominent.
This wet heath community is characteristic ofmoist and generally acid and oligotrophic peatsand peaty mineral soils in the wetter western andnorthern parts of Britain. It is associated with thin-ner or better drained areas of ombrogenous peatwith a surface pH typically between 4 and 5. Thecommunity is particularly well represented in thewest and south-west of Scotland, through Walesand less extensively in the Lake District, Dartmoorand Exmoor.
Grazing and burning have important effects onthe floristics and structure of this community, anddraining and peat-cutting have extended its coverage to formerly deeper and wetter peats.Without burning or grazing, less damaged standsmay be able to revert to blanket mire. However,cessation of burning, especially on peat that iswell aerated or where there has been drainage,may precipitate a vigorous expansion of Molinia.Although progression to woodland is theoreticallypossible over most, if not all, of its altitudinalrange, widespread deforestation has often re-moved potential seed-parents, and continuedgrazing by livestock and deer and sporadic burn-ing may be enough to set back succession contin-ually. However, extensive tracts of this kind ofvegetation have been replaced by coniferous forestafter the ground has been drained.
M15 Scirpus cespitosus –Erica tetralix wet heath
M14 Schoenus nigricans –Narthecium ossifragum mire
This mire type includes mildly calcicolousSchoenus vegetation of south-west England that isnot readily integrated into Schoenus nigricans –Juncus subnodulosus mire (M13) and with a lessvaried flora. Schoenus nigricans is usually domi-nant and Molinia caerulea is generally abundant.A mixture of these two species usually cover theground. Juncus subnodulosus is absent in contrastto M13. Small calcicolous herbs are generallyabsent. Narthecium ossifragum and Anagallistenella are constants while Drosera rotundifolia,growing on cushions of Sphagnum, is less com-mon. Erica tetralix, or occasionally Calluna vul-garis, grows on Schoenus or Molinia tussocks.Some stands have a local abundance of Myricagale.
Bryophytes are variable and also less calcicolousin character than in M13. Campylium stellatum andAneura pinguis are frequent and together withScorpidium scorpioides and, less commonly,Drepanocladus revolvens, can form extensive matsin runnels. Sphagnum spp. are a consistent feature,particularly on tussocks. Sphagnum subnitens ismost common and S. auriculatum is frequent.Hypnum jutlandicum is preferential and there maybe patches of hepatics including Kurzia paucifloraand Calypogeia species.
This community is characteristic of peats andmineral soils irrigated by moderately base-richand calcareous ground waters of a pH rangebetween 5 and 7. It characteristically occurs as iso-lated flushes among wet heath and moorland veg-etation, but it is also associated with soligenouszones within valley mires. The community occursvery locally in Cornwall, east Devon, south-eastDorset and the New Forest. It may also be found inWales but it is replaced in comparable situationson north-western blanket bogs by Schoenus-domi-nated stands of Scirpus cespitosus – Erica tetralixwet heath (M15).
The community only occurs very locally. Thisis partly because of the natural scarcity of suitablehabitats, but also because of the reduction in itsextent by human activities such as drainage andagricultural improvement. Occasional burningand light grazing are also of common occurrenceover the tracts of heath in which this kind of mireusually occurs, although these activities are probably not very damaging. In the absence ofgrazing or burning it is expected that some standsof this community would progress towards wet woodland.
No sub-communities.
37
Nar
thec
ium
oss
ifra
gum
fai
rly
com
mon
, bu
t ot
her
sp
ecie
sli
sted
op
pos
ite
all
scar
ce.
Nar
thec
ium
oss
ifra
gum
an
d
Eri
oph
oru
m a
ngu
stif
oliu
mfr
equ
ent
wit
h S
ph
agn
um
pal
ust
re c
omm
on. M
yric
aga
le o
ften
fou
nd
.
Dro
sera
rot
un
dif
olia
an
dsm
all
sed
ges
at m
ost
occa
-si
onal
. Sp
hag
nu
m c
arp
etp
atch
y, b
ut
S. p
apil
losu
mqu
ite
freq
uen
t.
Eri
ca c
iner
eafr
equ
ent,
so
met
imes
abu
nd
ant,
bu
tV
acci
niu
m m
yrti
llu
s ra
re.
Rac
omit
riu
m l
anu
gin
osu
mco
mm
on a
nd
Cla
don
ia s
pp
.of
ten
abu
nd
ant.
Eri
ca c
iner
eara
re b
ut
Vac
cin
ium
myr
till
us
fre-
quen
t, c
omm
only
wit
hN
ard
us
stri
cta,
Ju
ncu
s sq
uar
rosu
san
d D
esch
amp
sia
flex
uos
a. R
acom
itri
um
la
nu
gin
osu
man
d
Cla
don
iasp
p. s
carc
e.
M15
a
Ca
rex
pa
nic
easu
b-co
mm
un
ity
Th
is i
s th
e ri
ches
t an
d m
ost
flor
isti
call
yd
isti
nct
su
b-co
mm
un
ity.
Mol
inia
caer
ule
a an
d E
rica
tet
rali
x re
tain
hig
hfr
equ
ency
; Sci
rpu
s ce
spit
osu
s an
d
Cal
lun
a vu
lgar
is a
re m
ore
spar
se.
Myr
ica
gale
som
etim
es h
as l
ocal
ab
un
dan
ce, b
ut
E. c
iner
ea a
nd
Vac
cin
ium
myr
till
us
alm
ost
tota
lly
abse
nt.
Pot
enti
lla
erec
ta a
nd
Pol
ygal
ase
rpyl
lifo
lia
are
very
com
mon
ly f
oun
dw
ith
Nar
thec
ium
oss
ifra
gum
an
d E
rica
angu
stif
oliu
m. D
rose
ra r
otu
nd
ifol
ia i
sp
refe
ren
tial
wit
h a
var
iety
of
spec
ies
such
as
Car
ex p
anic
ea,C
. ech
inat
a,C
. nig
ra,C
. pu
lica
ris,
C. d
emis
sa,
C. d
ioic
a,S
elag
inel
la s
elag
inoi
des
,P
ingu
icu
la v
ulg
aris
,Su
ccis
a p
rate
nsi
s,V
iola
pal
ust
ris,
Jun
cus
bulb
osu
san
d D
acty
lorh
iza
mac
ula
ta s
sp.
mac
ula
ta. T
he
Sp
hag
nu
m c
arp
et i
s al
so d
isti
nct
ive,
as
ind
icat
ed a
bove
,w
ith
Sp
hag
nu
m p
alu
stre
also
oft
enab
un
dan
t an
d w
ith
S. c
apil
lifo
liu
mp
atch
y.
Th
is a
nd
th
e Ty
pic
al s
ub-
com
mu
nit
yar
e p
arti
cula
rly
com
mon
in
th
e w
est
of S
cotl
and
.
M15
b
Typ
ical
su
b-co
mm
un
ity
Th
e d
omin
ants
her
e ar
e ve
ry v
aria
ble.
S
cirp
us
cesp
itos
us
and
Cal
lun
a vu
lgar
ism
ay s
har
e d
omin
ance
, or
Cal
lun
a an
dM
olin
ia c
aeru
lea
may
pre
dom
inat
e,
Mol
inia
an
d E
rica
tet
rali
x or
Mol
inia
alon
e m
ay b
e d
omin
ant.
Myr
ica
gale
is q
uit
e co
mm
on b
ut
not
abu
nd
ant.
Nar
thec
ium
oss
ifra
gum
an
d E
riop
hor
um
angu
stif
oliu
m a
re f
requ
ent
as i
n M
15a,
but
smal
l se
dge
s ar
e ge
ner
ally
sp
arse
,w
ith
on
ly C
arex
pan
icea
an
d C
. ech
ina-
ta o
ccas
ion
al a
nd
fen
ass
ocia
tes
very
un
com
mon
. Nar
du
s st
rict
a an
d J
un
cus
squ
arro
sus
may
sh
ow l
ocal
pro
mi-
nen
ce. E
riop
hor
um
vag
inat
um
is
a lo
w-c
over
occ
asio
nal
. Sp
hag
nu
m p
apil
-lo
sum
is
freq
uen
t an
d l
ocal
ly a
bun
dan
tan
d O
don
tosc
his
ma
sph
agn
i of
ten
p
rese
nt.
In
som
e st
and
s S
ph
agn
um
sp
p. a
re s
par
se a
nd
mos
ses
such
as
Rac
omit
riu
m l
anu
gin
osu
m, D
icra
nu
msc
opar
ium
,Hyp
nu
m c
up
ress
ifor
me
and
Cam
pyl
opu
s p
arad
oxu
s p
rovi
de
mos
tof
th
e co
ver.
Th
is a
nd
th
e C
arex
pan
icea
sub-
com
mu
nit
y ar
e p
arti
cula
rly
com
mon
in
th
e w
est
of S
cotl
and
.
M15
c
Cla
don
iasp
p. s
ub-
com
mu
nit
y
All
fou
r p
ossi
ble
dom
inan
ts h
ave
hig
hfr
equ
ency
bu
t C
allu
na
vulg
aris
usu
ally
pre
dom
inat
es. P
oten
till
a er
ecta
rem
ain
sco
nst
ant,
bu
t P
olyg
ala
serp
ylli
foli
a an
dN
arth
eciu
m o
ssif
ragu
m a
re l
ess
com
-m
on a
nd
Eri
oph
oru
m a
ngu
stif
oliu
man
dM
yric
a ga
le v
ery
scar
ce. S
ph
agn
um
spp
. are
on
ly p
oorl
y re
pre
sen
ted
an
dH
ypn
um
cu
pre
ssif
orm
e/ju
tlan
dic
um
an
d R
acom
itri
um
lan
ugi
nos
um
beco
me
freq
uen
t. C
lad
onia
sp
p. a
re a
bun
dan
t,p
arti
cula
rly
Cla
don
ia i
mp
exa
and
C
. un
cial
is t
oget
her
wit
h C
. arb
usc
ula
,C
. pyx
idat
a,C
. coc
cife
ra a
nd
C. g
raci
lis.
Th
is s
ub-
com
mu
nit
y is
esp
ecia
lly
com
mon
in
th
e d
rier
reg
ion
s of
th
e d
istr
ibu
tion
of
M15
.
M15
d
Va
ccin
ium
myr
till
us
sub-
com
mu
nit
y
Mix
ture
s of
Mol
inia
cae
rule
a an
d
Cal
lun
a vu
lgar
is g
ener
ally
dom
inat
ew
ith
Sci
rpu
s ce
spit
osu
s an
d E
rica
tetr
alix
bot
h r
ath
er u
nev
en, o
ften
w
ith
som
e V
acci
niu
m m
yrti
llu
s.C
omm
only
th
ere
are
smal
l tu
ssoc
ks
of N
ard
us
stri
cta,
Jun
cus
squ
arro
sus,
Des
cham
psi
a fl
exu
osa
and
mor
e oc
casi
onal
ly s
ome
An
thox
anth
um
odor
atu
m,F
estu
ca o
vin
a/vi
vip
ara,
F. r
ubr
a,Lu
zula
mu
ltif
lora
an
d
Car
ex p
ilu
life
ra. S
ph
agn
um
sp
p. a
re
infr
equ
ent,
th
eir
pla
ce b
ein
g ta
ken
by
Hyp
nu
m c
up
ress
ifor
me/
jutl
and
icu
m,
Dic
ran
um
sco
par
ium
,Ple
uro
ziu
msc
hre
beri
,Pla
giot
hec
ium
un
du
latu
m,
Pol
ytri
chu
m c
omm
un
e an
dR
hyt
idia
del
ph
us
lore
us.
Rac
omit
riu
mla
nu
gin
osu
m a
nd
Cla
don
ia s
pp
. ar
e sc
arce
.
Th
is s
ub-
com
mu
nit
y is
esp
ecia
lly
com
mon
in
th
e d
rier
reg
ion
s of
th
e d
istr
ibu
tion
of
M15
.
Usu
ally
sm
all
stan
ds,
oft
enin
soa
kway
s. S
ph
agn
um
ca
rpet
ext
ensi
ve w
ith
fre
-qu
ent
Sp
hag
nu
m r
ecu
rvu
man
d S
. su
bnit
ens.
Dro
sera
rotu
nd
ifol
ia c
omm
on a
nd
scat
tere
d s
mal
l se
dge
s su
chas
Car
ex e
chin
ata,
C. p
anic
eaan
d C
. nig
ra.
M15
38
This community is characteristically dominatedby mixtures of Erica tetralix, Calluna vulgaris andMolinia caerulea, but their proportions are veryvariable, being influenced by differences in thewater regime and trophic state of the soils, andalso by grazing and burning. Erica tetralix is oftenvigorous, particularly on wetter soils, whileCalluna is often subordinate and weak (although itmay be abundant in drier stands or where controlled burning is carried out). No other sub-shrubs attain a high frequency, although Ericacinerea and Ulex gallii may be abundant in transitions to drier heaths in south-west Englandand E. cinerea and U. minor can occur in similarsituations further east. In some situations Moliniamay be dominant.
This community may have no other, or only sporadic, vascular associates. The commonest vas-cular associate, where present, is Scirpus cespito-sus. Eriophorum angustifolium and Nartheciumossifragum are quite frequent, as is Drosera rotun-difolia in wetter hollows. Myrica gale occurs occa-sionally, sometimes with local abundance.
Most characteristic of the bryophyte layer indrier situations is Sphagnum compactum, a con-stant and strong preferential for the community. Inwetter places S. tenellum may be present. Thesespecies may occur as scattered cushions or form acontinuous carpet, sometimes with several other
Sphagnum spp. as well as a number of otherbryophytes, between the dominants. Lichens mayalso be present, especially larger Cladonia speciessuch as C. impexa and C. uncialis.
This wet heath community is found on acidand oligotrophic mineral soils or shallow peatsthat generally have a surface pH of between 3.5and 4.5 and that are at least seasonally water-logged. It is characteristic of the south of lowlandEngland, being particularly associated with thesurrounds of valley mires maintained by a locallyhigh water table. It is also found through Wales,and in northern England and Scotland, where itextends on to thin ombrogenous peats at higheraltitudes.
Grazing and burning are important in main-taining the vegetation, and burning is able totransform the appearance of particular stands overshort periods of time, producing considerablestructural diversity within a small area. Withoutany grazing or burning most stands would proba-bly progress to woodland, and this has happenedto some stands lying within tracts of heath oncommons in south-east England where traditionalmanagement has fallen into disuse. The combina-tion of frequent burning, draining, and damagedue to other operations such as military manoeu-vres and mineral extraction, have led to an irre-trievable loss of this community in many areasand its distribution has been considerably frag-mented with remaining stands closely hemmed inby coniferous plantations or intensive agriculturalland.
M16 Erica tetralix – Sphagnum compactum wet heath
39
Sci
rpu
s ce
spit
osu
s an
d
Nar
thec
ium
oss
ifra
gum
ge
ner
ally
fre
quen
t bu
t li
sted
asso
ciat
es o
f M
16b
usu
ally
un
com
mon
.
Su
b-sh
rub
cove
r ge
ner
ally
pat
chy,
bu
t S
ph
agn
um
ca
rpet
qu
ite
exte
nsi
ve w
ith
freq
uen
t K
urz
ia p
auci
flor
a.W
ette
r h
ollo
ws
and
ru
nn
els
hav
e D
rose
ra r
otu
nd
ifol
iaan
d o
ften
D. i
nte
rmed
ia,
Rh
ynch
osp
ora
alba
an
dlo
call
y R
. fu
sca
as s
ub-
com
mu
nit
y p
refe
ren
tial
s.
Sp
hag
nu
m c
arp
et o
ften
ver
yp
atch
y an
d s
omet
imes
abs
ent
and
M16
c as
soci
ates
har
dly
ever
fou
nd
.
M16
c
Rh
ynch
osp
ora
alb
a–
Dro
sera
in
term
edia
sub-
com
mu
nit
y
Mol
inia
cae
rule
a an
d E
rica
tet
rali
xre
mai
n v
ery
freq
uen
t bu
t C
allu
na
vul-
gari
sis
les
s co
mm
on a
nd
th
e co
ver
ofal
l th
ree
is r
edu
ced
. In
th
e in
terv
enin
gop
en a
reas
is
an e
xten
sive
cov
er o
fS
ph
agn
um
com
pac
tum
an
d S
. ten
ellu
mw
ith
lea
fy h
epat
ics
and
loc
ally
pro
mi-
nen
t C
lad
onia
sp
ecie
s, p
arti
cula
rly
C. i
mp
exa.
Th
ere
are
scat
tere
d s
mal
ltu
ssoc
ks o
f S
cirp
us
cesp
itos
us
and
ofte
n N
arth
eciu
m o
ssif
ragu
man
dE
riop
hor
um
an
gust
ifol
ium
.Mor
e d
isti
nct
ive
are
the
pre
fere
nti
als
list
ed a
bove
.
Th
is s
ub-
com
mu
nit
y is
con
cen
trat
ed i
nth
e N
ew F
ores
t an
d P
oole
Har
bou
r.
M16
a
Typ
ical
su
b-co
mm
un
ity
All
var
iati
ons
in t
he
pro
por
tion
s of
M
olin
ia c
aeru
lea,
Eri
ca t
etra
lix
and
Cal
lun
a vu
lgar
is c
an b
e fo
un
d i
n t
his
sub-
com
mu
nit
y so
th
e ap
pea
ran
ce i
sve
ry d
iver
se. W
her
e th
eir
cove
r is
op
en,
Sp
hag
nu
m c
omp
actu
m a
nd
S. t
enel
lum
can
be
very
fre
quen
t an
d o
ften
abu
n-
dan
t. A
mon
g ot
her
bry
oph
ytes
Hyp
nu
mju
tlan
dic
um
an
d K
urz
ia p
auci
flor
a ar
eth
e co
mm
ones
t sp
ecie
s, w
hil
eC
amp
ylop
us
brev
ipil
us
is v
ery
con
sist
ent
in s
ome
area
s. L
ich
ens,
p
arti
cula
rly
Cla
don
ia i
mp
exa,
can
al
so b
e fr
equ
ent.
Th
is s
ub-
com
mu
nit
y is
fou
nd
th
rou
ghou
t th
e so
uth
of
Bri
tain
an
d a
sm
ore
imp
over
ish
ed s
tan
ds
furt
her
nor
th.
M16
b
Su
ccis
a p
rate
nsi
s–
Ca
rex
pa
nic
easu
b-co
mm
un
ity
Mol
inia
cae
rule
a te
nd
s to
p
red
omin
ate
wit
h E
rica
tet
rali
xan
d C
allu
na
vulg
aris
hav
ing
hig
h f
requ
enci
es. T
he
vasc
ula
rfl
ora
is r
ich
er t
han
in
M16
aw
ith
Pot
enti
lla
erec
ta a
nd
Su
ccis
a p
rate
nsi
s be
ing
con
-st
ant
and
th
e sp
ecie
s li
sted
abov
e p
refe
ren
tial
. Myr
ica
gale
som
etim
es s
how
s lo
cal
abu
nd
ance
. Bry
oph
ytes
an
dli
chen
s te
nd
to
be l
ess
com
mon
in t
his
su
b-co
mm
un
ity,
bu
t u
nu
sual
ly S
ph
agn
um
au
ricu
latu
mca
n b
e fr
equ
ent
and
loc
ally
abu
nd
ant.
Th
is s
ub-
com
mu
nit
y oc
curs
thro
ugh
out
sou
th-w
est
En
glan
dan
d p
erh
aps
else
wh
ere.
Mol
inia
cae
rule
a u
sual
lyd
omin
ant
wit
h S
cirp
us
cesp
itos
us
and
Nar
thec
ium
ossi
frag
um
les
s co
mm
onth
an u
sual
, sca
tter
ed p
lan
tsof
Pot
enti
lla
erec
ta a
nd
S
ucc
isa
pra
ten
sis
freq
uen
t,w
ith
occ
asio
nal
Pol
ygal
a se
rpyl
lifo
lia,
Car
ex p
anic
ea,
Sal
ix r
epen
s,C
irsi
um
d
isse
ctu
m a
nd
Ser
ratu
lati
nct
oria
. Bry
oph
ytes
usu
ally
sp
arse
.
M16
d
Jun
cus
squ
arr
osu
s–
Dic
ran
um
sc
opa
riu
msu
b-co
mm
un
ity
Mol
inia
cae
rule
ara
rely
has
hig
h c
over
and
may
be
abse
nt
and
alt
hou
gh
Eri
ca t
etra
lix
reta
ins
con
stan
cy,
Cal
lun
a vu
lgar
is i
s u
sual
ly d
omin
ant.
S
cirp
us
cesp
itos
us
is m
ore
freq
uen
t an
d h
as h
igh
er c
over
th
an i
n o
ther
su
b-co
mm
un
itie
s. S
ph
agn
um
com
pac
tum
is o
ften
abu
nd
ant
and
has
a h
igh
fr
equ
ency
tog
eth
er w
ith
S. t
enel
lum
wh
ile
S. c
apil
lifo
liu
m a
nd
S. s
ubn
iten
sar
e re
lati
vely
sca
rce.
Tog
eth
er w
ith
th
e br
yop
hyt
es l
iste
d a
bove
lic
hen
s ar
eof
ten
pro
min
ent,
wit
h C
lad
onia
im
pex
aan
d C
. un
cial
is e
spec
iall
y co
mm
on.
Th
is i
s th
e u
sual
su
b-co
mm
un
ity
in t
he
nor
th a
nd
eas
t of
Bri
tain
.
Ver
y va
riab
le m
ixtu
res
of C
allu
na
vulg
aris
,Eri
ca
tetr
alix
an
d M
olin
ia c
aeru
lea
gen
eral
ly d
omin
ate
wit
hoc
casi
onal
Sci
rpu
s ce
spit
osu
san
d J
un
cus
squ
arro
sus.
Oth
er a
ssoc
iate
s li
sted
fo
r M
16d
rar
e.
Mol
inia
cae
rule
a re
du
ced
in
freq
uen
cy a
nd
abu
nd
ance
and
Cal
lun
a vu
lgar
is o
ften
exce
edin
g E
rica
tet
rali
x.F
requ
ent
tuss
ocks
of
Sci
rpu
sce
spit
osu
s an
d J
un
cus
squ
arro
sus.
Hyp
nu
m
cup
ress
ifor
me,
Dic
ran
um
scop
ariu
m,R
acom
itri
um
lan
ugi
nos
um
an
dD
iplo
ph
yllu
m a
lbic
ans
all
com
mon
. Cla
don
iasp
ecie
s of
ten
pre
sen
t.
M16
40
This community is dominated by mixtures ofmonocotyledons, ericoid sub-shrubs and Sphagnumspp. It can occur as extensive, relatively uniformtracts, or as hummock and hollow complexes,with this community giving way to bog pool vege-tation in the hollows. Among the bulkier vascularspecies, the most common are Scirpus cespitosus,Eriophorum vaginatum, Molinia caerulea, Callunavulgaris and Erica tetralix; mixtures of which forma rather open uneven-topped tier which is 20-30 cm tall. Myrica gale also has occasional localabundance in this stratum.
Eriophorum angustifolium and Nartheciumossifragum are both very frequent and Droserarotundifolia is very common in wetter areas.Potentilla erecta is a constant which helps to dis-tinguish this community from other Sphagnetaliamires (M18-M21). Other species found at low fre-quencies throughout are Pedicularis sylvatica,Huperzia selago, Juncus acutiflorus, Festuca ovinaand Carex echinata. Vaccinium myrtillus, Empetrumnigrum ssp. nigrum and Rubus chamaemorusare all scarce, in contrast to Calluna vulgaris-Eriophorum vaginatum blanket mire (M19).
Sphagnum spp. are an important component ofthe ground layer. Sphagnum capillifolium and S. papillosum are constants and may be accompa-
nied by S. tenellum, S. subnitens and otherspecies, forming luxuriant carpets. Such carpetstypically have a variety of leafy hepatics includingOdontoschisma sphagni, Mylia anomala, M. tay-lori and Pleurozia purpurea. Racomitrium lanugi-nosum is a common moss throughout, but becomesabundant on hummock tops and in degradedmires. Lichens, particularly larger Cladoniaspecies, can be prominent and tend to be associat-ed with R. lanuginosum.
This community is the characteristic blanketbog vegetation of the more oceanic parts of Britain,occurring extensively on waterlogged ombroge-nous peat. The peats show varying humificationbut are typically highly acidic, with a surface pHusually not above 4 and often less. It is a commu-nity of lower altitudes where extreme humidity iscombined with a relatively mild winter climate. Itis largely confined to western Britain from thewestern Highlands of Scotland and the WesternIsles, to south-west Scotland, the Lake District,Wales and south-west England.
Burning, marginal peat-cutting, and drainagehave often resulted in surface drying of the peatand hence a modification of the vegetation. It isalso possible that natural climatic change too hasplayed a part in the degeneration of the blanketbogs occupied by this type of community.However, this community still remains as climaxvegetation in the more oceanic parts of Britain.
M17 Scirpus cespitosus –Eriophorum vaginatum blanket mire
41
Th
e u
sual
vas
cula
r d
omin
ants
are
Cal
lun
a vu
lgar
is a
nd
Sci
rpu
s ce
spit
osu
s, w
ith
Eri
ca
tetr
alix
an
d M
olin
ia c
aeru
lea
of r
edu
ced
im
por
tan
ce a
nd
M
yric
a ga
le r
are.
Dro
sera
rotu
nd
ifol
ia a
t m
ost
occa
sion
al.
Sp
hag
nu
mco
ver
rath
er i
mp
over
ish
edan
d l
eafy
hep
atic
s in
freq
uen
t.
Rac
omit
riu
m l
anu
gin
osu
m v
ery
com
mon
wit
h s
ever
al
Cla
don
ia s
pec
ies.
E
rica
cin
erea
occ
asio
nal
an
d l
ocal
lyab
un
dan
t.
Vac
cin
ium
myr
till
us
and
Em
pet
rum
nig
rum
very
sca
rce.
Nar
du
s st
rict
a an
d J
un
cus
squ
arro
sus
occa
sion
al.
M17
b
Cla
don
iasp
p. s
ub-
com
mu
nit
y
Cal
lun
a vu
lgar
is a
nd
Sci
rpu
s ce
spit
osu
s ar
e fa
irly
co
nsi
sten
t co
-dom
inan
ts w
ith
Mol
inia
cae
rule
a an
d
Eri
ca t
etra
lix
pla
yin
g a
subo
rdin
ate
role
an
d E
riop
hor
um
vagi
nat
um
dis
tin
ctly
pat
chy.
Myr
ica
gale
is s
carc
e an
dE
rica
cin
erea
qu
ite
freq
uen
t an
d l
ocal
ly p
rom
inen
t. T
he
Sp
hag
nu
m c
arp
et i
s m
uch
im
pov
eris
hed
wit
h S
ph
agn
um
cap
illi
foli
um
as
the
mai
n s
pec
ies,
oft
en r
ath
er p
atch
y,
and
all
oth
er s
pec
ies
red
uce
d i
n f
requ
ency
. Th
e le
afy
hep
atic
s of
M17
a ar
e u
nco
mm
on, w
ith
Myl
ia t
aylo
ri a
nd
Dip
lop
hyl
lum
albi
can
s p
refe
ren
tial
at
low
fre
quen
cies
.R
acom
itri
um
lan
ugi
nos
um
an
d C
lad
onia
sp
p. a
rein
crea
sed
in
fre
quen
cy a
nd
abu
nd
ance
, par
ticu
larl
yC
lad
onia
im
pex
a,C
. un
cial
isan
d C
. arb
usc
ula
.
Th
is s
ub-
com
mu
nit
y al
ong
wit
h t
he
Jun
cus
–R
hyt
idia
del
ph
us
sub-
com
mu
nit
y oc
curs
in
th
e w
est
but
they
ext
end
th
e ra
nge
of
the
com
mu
nit
y on
to
dri
er p
eats
,m
ost
not
ably
in
sou
th-w
est
and
eas
tern
Sco
tlan
d.
M17
c
Jun
cus
squ
arr
osu
s–
Rh
ytid
iad
elp
hu
s lo
reu
ssu
b-co
mm
un
ity
Cal
lun
a vu
lgar
is a
nd
Sci
rpu
s ce
spit
osu
s ar
e th
e m
ain
va
scu
lar
dom
inan
ts w
ith
Eri
ca t
etra
lix
and
esp
ecia
lly
Mol
inia
cae
rule
a be
ing
red
uce
d. M
yric
a ga
le i
s ab
sen
t an
dE
rica
cin
erea
ver
y sc
arce
. Th
ere
is a
mar
ked
in
crea
se i
nJu
ncu
s sq
uar
rosu
s,N
ard
us
stri
cta,
Des
cham
psi
a fl
exu
osa
and
Car
ex n
igra
, an
d w
ith
th
em A
gros
tis
can
ina
ssp
. can
i-n
a, A
nth
oxan
thu
m o
dor
atu
m a
nd
Lu
zula
mu
ltif
lora
can
be
fou
nd
. Of
the
Sp
hag
nu
m s
pp
., S
ph
agn
um
pap
illo
sum
is
usu
ally
th
e m
ost
abu
nd
ant.
Th
ere
is a
dis
tin
ctiv
e co
nti
n-
gen
t of
mos
ses:
Hyp
nu
m c
up
ress
ifor
me/
jutl
and
icu
m,
Rh
ytid
iad
elp
hu
s lo
reu
s an
d D
icra
nu
m s
cop
ariu
m a
re a
llve
ry f
requ
ent,
wh
ile
Pol
ytri
chu
m c
omm
un
e,P.
alp
estr
e,P
lagi
oth
eciu
m u
nd
ula
tum
,Au
laco
mn
ium
pal
ust
re,
Pti
lid
ium
cil
iare
,Poh
lia
nu
tan
san
d C
amp
ylop
us
par
adox
us
are
mor
e oc
casi
onal
bu
t p
refe
ren
tial
.
Th
is s
ub-
com
mu
nit
y al
ong
wit
h t
he
Cla
don
ia s
ub-
com
mu
nit
y oc
curs
in
th
e w
est
but
they
ext
end
th
e ra
nge
of
th
e co
mm
un
ity
on t
o d
rier
pea
ts, m
ost
not
ably
in
so
uth
-wes
t an
d e
aste
rn S
cotl
and
.
M17
a
Dro
sera
rot
un
dif
olia
– S
ph
agn
um
spp
. su
b-co
mm
un
ity
Th
is h
as a
con
sist
ent
rep
rese
nta
tion
of
all
th
e co
mm
un
ity
con
stan
ts.
Am
ong
vasc
ula
r d
omin
ants
mix
ture
s of
Cal
lun
a vu
lgar
is a
nd
Sci
rpu
s ce
spit
osu
sor
Cal
lun
a vu
lgar
is a
nd
Mol
inia
caer
ule
a u
sual
ly m
ake
up
th
e bu
lk o
fth
e co
ver,
wit
h E
riop
hor
um
vag
inat
um
som
etim
es s
how
ing
loca
l ab
un
dan
ce
in h
igh
er a
reas
an
d E
rica
tet
rali
xin
wet
ter
par
ts. D
rose
ra r
otu
nd
ifol
iais
str
ongl
y p
refe
ren
tial
. Sp
hag
nu
m
spp
. are
ext
ensi
ve; S
ph
agn
um
ca
pil
lifo
liu
m a
nd
S. p
apil
losu
m a
rem
ost
abu
nd
ant
wit
h S
. com
pac
tum
occa
sion
al a
nd
S. t
enel
lum
an
d
S. s
ubn
iten
s fr
equ
ent.
Com
mon
lea
fyh
epat
ics
are
Ple
uro
zia
pu
rpu
rea
and
O
don
tosc
his
ma
sph
agn
i. R
acom
itri
um
lan
ugi
nos
um
is a
lso
freq
uen
t bu
t on
lyas
sca
tter
ed s
hoo
ts.
Th
is s
ub-
com
mu
nit
y oc
curs
th
rou
ghou
tth
e ra
nge
of
M17
, bu
t it
is
par
ticu
larl
yex
ten
sive
in
nor
th-w
est
Sco
tlan
d.
Eri
ca t
etra
lix
and
Mol
inia
caer
ule
a u
sual
ly w
ell
rep
rese
nte
d w
ith
Dro
sera
rotu
nd
ifol
ia v
ery
freq
uen
tan
d M
yric
a ga
le l
ocal
ly
ple
nti
ful.
Ext
ensi
ve a
nd
va
ried
Sp
hag
nu
m c
arp
etw
ith
lea
fy h
epat
ics
ofte
np
rom
inen
t.
Jun
cus
squ
arro
sus,
Nar
du
s st
rict
a an
d D
esch
amp
sia
flex
u-
osa
freq
uen
t w
ith
sm
all
amou
nts
of
Vac
cin
ium
myr
till
us
and
occ
asio
nal
Em
pet
rum
nig
rum
, bu
t E
rica
cin
erea
rar
e.
Rac
omit
riu
m l
anu
gin
osu
m o
ccas
ion
al a
nd
Cla
don
iasp
ecie
s u
nco
mm
on.
M17
42
This community is generally dominated bySphagnum spp. Ericoid sub-shrubs and mono-cotyledons are often subordinate. It can be foundas undulating carpets or can comprise lawn andhummock components. The bulkier vascular plantstypically form a low, patchy canopy with Callunavulgaris, Erica tetralix and Eriophorum vaginatumbeing the commonest species and Scirpus cespito-sus slightly less frequent. Erica tetralix tends topredominate on wetter ground where shoots ofEriophorum angustifolium can also be abundant.Calluna, Scirpus and E. vaginatum are found moretypically on the drier areas.
Sphagnum spp. make up the most importantcomponent of the vegetation. Both Sphagnumpapillosum and S. capillifolium are very commonand S. tenellum is also a constant but less abun-dant. Sphagnum magellanicum is a preferentialspecies and a major peat-builder. S. imbricatum isa distinctive species where present. Over gently-undulating surfaces the Sphagnum spp. form anirregular patchwork, but with increasing differen-tiation of hummocks and hollows they show a ver-tical stratification. On hummock tops and sides S. capillifolium is abundant, and S. papillosum,
S. magellanicum, and a little S. tenellum predom-inate on the surrounds to wetter depressions.
Other bryophytes are generally subordinate butcan be frequent and locally abundant. The leafyhepatics Odontoschisma sphagni and Myliaanomala are both common, but Pleurozia pur-purea is generally absent. Aulacomnium palustreand Hypnum cupressiforme/jutlandicum are fre-quent mosses.
This vegetation is characteristic of waterloggedombrogenous peats, typically at low altitudes inmoderately oceanic parts of Britain. It is charac-teristic of raised bogs where it is the main com-munity of the active plane, but is also found with-in blanket mires and in some basin mires on acidpeat. The peats it covers are usually deep with auniformly acid surface with a pH of about 4, andoligotrophic. It is widespread but local throughthe lowlands of Wales, up to the Scottish Bordersand in south-west Scotland. There are also locali-ties in southern England and east Scotland.
Erica tetralix – Sphagnum papillosum raisedand blanket mire vegetation is a climax of ahydroseral succession. However, the typical habi-tat of this community has been widely affected byvarious treatments, notably peat-cutting, burningand grazing, and these have often modified thevegetation or reduced it to fragmentary stands.
M18 Erica tetralix – Sphagnumpapillosum raised and blanket mire
43
M18
Sphagnum spp. abundant,with Sphagnum capillifoliumusually dominant, S. papillo-sum frequent but usually subordinate and S. magellan-icum only occasional.Narthecium ossifragum andVaccinium oxycoccos occa-sional and Drosera rotundifo-lia and Andromeda polifoliavery scarce. Sub-shrubs oftenquite vigorous. Cladonia species frequent and locallyabundant.
M18a
Sphagnum magellanicum –Andromeda polifolia sub-community
All the community vascular constantsare of high frequency but very oftennone is dominant. Sphagnum spp. form an obvious and extensive carpetin which Sphagnum papillosum, oftenwith abundant S. magellanicum, pre-dominates along with the constants S. tenellum and S. capillifolium.Scattered through are frequent individuals of Drosera rotundifoliaand Narthecium ossifragum with thepreferentials Vaccinium oxycoccos andAndromeda polifolia. Cladonia spp.and Pleurozium schreberi are typicallyof low frequency.
This sub-community occurs throughoutthe range of M18.
Sphagnum spp. luxuriant,with Sphagnum magellan-icum frequent and abundant,along with S. papillosum inwetter lawns. Nartheciumossifragum and Droserarotundifolia common andVaccinium oxycoccos andAndromeda polifolia especially distinctive.
M18b
Empetrum nigrum ssp. nigrum –Cladonia spp. sub-community
Calluna vulgaris, Scirpus cespitosusand Eriophorum vaginatum tend tohave higher covers here, Calluna vulgaris in particular becoming morevigorous and abundant. Empetrumnigrum is also frequent among them. Among the Sphagnum spp., S. capillifolium is strongly dominant,although S. papillosum is still frequent. S. tenellum is patchy and S. magellanicum only occasional. Other mosses become frequent, with Pleurozium schreberi andRhytidiadelphus loreus being goodpreferentials; a range of hepatics is alsocommon. There is a marked increase in Cladonia spp., notably Cladoniaimpexa, C. uncialis and C. arbuscula,each of which can be locally abundant.
This sub-community occurs throughoutthe range of M18.
44
This vegetation is generally dominated by mixtures of Eriophorum vaginatum and ericoidsub-shrubs. Sphagnum spp. can be prominentover wetter ground but are not as luxuriant or richas in Scirpus cespitosus – Eriophorum vaginatumblanket mire (M17) or Erica tetralix – Sphagnumpapillosum raised and blanket mire (M18). Theground surface is often uneven, but does not showtrue hummock and hollow relief. Eriophorumvaginatum is abundant and at least co-dominant.Normally this community has very frequent occurrences of Calluna vulgaris, Vaccinium myrtillus and Empetrum nigrum ssp. nigrum and,at higher altitudes, V. vitis-idaea, V. uliginosumand E. nigrum ssp. hermaphroditum. OverallCalluna is the most common co-dominant alongwith Eriophorum vaginatum, but diverse mixturesof these sub-shrubs are very frequent. Vascularassociates are few, the commonest beingEriophorum angustifolium, and Rubus chamae-morus, a species which is distinctive for this com-munity. Deschampsia flexuosa and Juncus squar-rosus occur occasionally throughout, and at high-er altitudes Carex bigelowii becomes frequent.
In contrast to the vascular plants, the bryophyteflora is rich, often with a cover exceeding 50%.The most frequent Sphagnum species is S. capilli-folium, which forms patches rather than carpets.Hypnaceous mosses are consistently present andPleurozium schreberi, Rhytidiadelphus loreus,Hypnum cupressiforme/jutlandicum and Plagio-thecium undulatum are all very frequent. Hylo-
comium splendens is common at higher altitudes. A variety of leafy hepatics occur in this
community and lichens are frequent. LargerCladonia spp. can be abundant on old Eriophorumhummocks.
This mire is the typical blanket bog vegetationof high-altitude ombrogenous peats present in the wet and cold climate of the uplands of north-ern Britain. In particular, it occurs on high-levelplateaux and broad watersheds, usually above300 m, and is confined to deeper peats, usuallymore than 2 m thick, on flat or gently-slopingground. The peats are usually well-humified,highly acidic with a surface pH often less than 4.They are not consistently waterlogged and maybecome surface oxidised in summer. Erosion ofthe peat is common. This community is found onthe higher ground in the Pennines, the centralHighlands of Scotland, and Wales.
Treatments such as burning and grazing are important in influencing the composition andstructure of the vegetation throughout the range ofthis community, in particular where stands formpart of unenclosed hill grazing or grouse moors. A stable diversity of bog vegetation can be maintained by careful burning on a rotation ofaround 10 years, or by moderate levels of grazing.However, frequent burning or heavy grazing contribute to the conversion of the Calluna vul-garis – Eriophorum vaginatum blanket mire toEriophorum vaginatum blanket mire (M20). Inother cases drainage can convert this communityinto heathland or grassland, and this type of blan-ket mire has been reclaimed for agriculture orforestry in many areas.
M19 Calluna vulgaris – Eriophorum vaginatum blanket mire
45
Eri
oph
oru
m v
agin
atu
m
usu
ally
abu
nd
ant
and
Ru
bus
cham
aem
oru
s fr
equ
ent.
S
cirp
us
cesp
itos
us
rare
an
dS
ph
agn
um
cov
er p
atch
y.
M19
a
Eri
ca t
etra
lix
sub-
com
mu
nit
y
Eri
oph
oru
m v
agin
atu
m c
an b
e co
-d
omin
ant
wit
h t
he
sub-
shru
bs t
hou
ghge
ner
ally
les
s ab
un
dan
t th
an i
n o
ther
sub-
com
mu
nit
ies.
Cal
lun
a vu
lgar
isis
oft
en t
he
pre
dom
inan
t su
b-sh
rub
wit
h s
ome
Em
pet
rum
nig
rum
ssp
.n
igru
m. E
rica
tet
rali
x is
pre
fere
nti
alan
d s
omet
imes
wit
h h
igh
cov
er.
Sci
rpu
s ce
spit
osu
s is
fre
quen
t an
dlo
call
y ab
un
dan
t. T
he
infr
equ
ency
of
Ru
bus
cham
aem
oru
sis
dis
tin
ctiv
e.
Sp
hag
nu
m s
pp
. ten
d t
o be
con
sist
entl
yab
un
dan
t w
ith
S. c
apil
lifo
liu
m b
ein
gco
mm
only
acc
omp
anie
d b
y S
. pap
illo
sum
.
Th
is i
s th
e u
sual
for
m f
oun
d a
t lo
wer
alti
tud
es t
hat
hav
e a
rath
er m
ore
ocea
nic
cli
mat
e, s
uch
as
in W
ales
an
d s
outh
-wes
t S
cotl
and
.
Eri
oph
oru
m v
agin
atu
m l
ess
abu
nd
ant,
Eri
ca t
etra
lix
mor
e co
mm
on a
nd
Sci
rpu
sce
spit
osu
s fr
equ
ent.
Ru
bus
cham
aem
oru
s ra
re. S
ph
agn
um
spp
. cov
er q
uit
e ex
ten
sive
.
Em
pet
rum
nig
rum
ssp
. h
erm
aph
rod
itu
m o
ccas
ion
alat
mos
t an
d o
ften
wit
h s
sp.
nig
rum
as
a re
pla
cem
ent.
V
acci
niu
m v
itis
-id
aea
also
occa
sion
al a
nd
V. u
ligi
nos
um
,Ju
ncu
s sq
uar
rosu
s an
d C
arex
bige
low
ii r
are.
Bry
oph
ytes
in
M19
c ra
re.
M19
b
Em
pet
rum
nig
rum
ssp
. nig
rum
sub-
com
mu
nit
y
Th
is s
ub-
com
mu
nit
y p
rese
rves
all
th
e fe
atu
res
of M
19 a
lth
ough
it
is v
ery
vari
able
in
all
its
str
uct
ura
l el
emen
ts.
Eri
oph
oru
m v
agin
atu
mis
usu
ally
ab
un
dan
t, w
ith
su
b-sh
rubs
pla
yin
g a
con
sist
ent
role
an
d C
allu
na
vulg
aris
bein
g th
e le
adin
g sp
ecie
s, t
hou
gh
Vac
cin
ium
myr
till
us
and
/or
Em
pet
rum
nig
rum
ssp
. nig
rum
,par
ticu
larl
y th
e la
tter
, can
in
crea
se g
reat
ly a
fter
burn
ing.
Eri
ca t
etra
lix
is v
ery
scar
ce
and
Sci
rpu
s ce
spit
osu
s an
d M
olin
iaca
eru
lea
hav
e a
low
fre
quen
cy. R
ubu
sch
amae
mor
us
how
ever
in
crea
ses
grea
t-ly
. Th
e S
ph
agn
um
flo
ra i
s im
pov
er-
ish
ed a
nd
on
dri
er g
rou
nd
hyp
nac
eou
sm
osse
s ar
e p
arti
cula
rly
abu
nd
ant.
Th
is f
orm
s th
e ri
cher
typ
e of
‘Pen
nin
ebl
anke
t bo
g’ e
xten
din
g n
orth
war
ds
thro
ugh
Ch
evio
t an
d t
he
Bor
der
s in
toea
ster
n S
cotl
and
.
M19
c
Va
ccin
ium
vit
is-i
da
ea–
Hyl
ocom
ium
sp
len
den
ssu
b-co
mm
un
ity
Th
is e
mbr
aces
all
th
e h
igh
-mon
tan
e bl
anke
t m
ire.
It p
rese
rves
all
th
e ge
ner
al f
lori
stic
fea
ture
s bu
t is
d
isti
nct
ive
in t
he
freq
uen
t an
d c
onsi
sten
t p
rese
nce
of V
acci
niu
m v
itis
-id
aea
and
Em
pet
rum
nig
rum
ssp
. her
map
hro
dit
um
an
d t
he
mor
e re
stri
cted
pre
s-en
ce o
f V.
uli
gin
osu
m. T
hes
e ar
e m
ixed
wit
h o
ther
sub-
shru
bs a
nd
usu
ally
wit
h a
bun
dan
t C
allu
na
vulg
aris
. Eri
oph
oru
m a
ngu
stif
oliu
m i
s le
ss c
om-
mon
, bu
t R
ubu
s ch
amae
mor
us
is v
ery
freq
uen
t.Ju
ncu
s sq
uar
rosu
s oc
curs
qu
ite
ofte
n, a
s d
o C
arex
bige
low
ii a
nd
Sci
rpu
s ce
spit
osu
s. S
ph
agn
um
sp
p.
can
be
quit
e p
rom
inen
t, w
ith
a r
ange
of
oth
erbr
yop
hyt
es i
ncl
ud
ing
the
hep
atic
Pti
lid
ium
cil
iare
.T
he
lich
en f
lora
is
usu
ally
wel
l d
evel
oped
.
Th
is s
ub-
com
mu
nit
y ex
ten
ds
to t
he
alti
tud
inal
lim
it o
f th
is k
ind
of
blan
ket
bog
in c
entr
alS
cotl
and
.
Th
ree
vari
ants
.
Em
pet
rum
ssp
. her
map
hro
dit
um
an
dV
acci
niu
m v
itis
-id
aea
con
stan
t an
dof
ten
co-
dom
inan
t w
ith
Cal
lun
a vu
lgar
is,V
. myr
till
us
and
Eri
oph
oru
mva
gin
atu
m. H
yloc
omiu
m s
ple
nd
ens,
Rac
omit
riu
m l
anu
gin
osu
m a
nd
Pol
ytri
chu
m a
lpes
tre
com
mon
in
th
e gr
oun
d l
ayer
.
M19
46
Eriophorum vaginatum mire comprises species-poor ombrogenous bog vegetation dominated by E. vaginatum, the tussocks of which form an openor closed canopy 10-30 cm high. The only other constant plant is E. angustifolium, which is usuallyfound as scattered shoots. Ericoid sub-shrubs arepatchy; Calluna vulgaris, Empetrum nigrum ssp.nigrum and Vaccinium myrtillus can each befound quite frequently and the last two may belocally abundant. Alternatively these species maybe reduced to sparse shoots. Deschampsia flexu-osa is fairly common while Festuca ovina, Juncussquarrosus, Scirpus cespitosus and Carex bigel-owii are all infrequent.
Bryophytes are sparse and patchy. Sphagnumspp. are scarce with Sphagnum capillifolium andS. papillosum the most usual species. Hypnaceousmosses are poorly represented; the only moss ofany frequency being Campylopus paradoxuswhich can be accompanied by Dicranum scopari-um. There may be occasional shoots of Ortho-dontium lineare, Pohlia nutans and Drepa-nocladus fluitans. A variety of leafy hepatics maybe present. Lichens are typically few in number.
Bulkier species like Cladonia arbuscula,C. uncialis and C. impexa can sometimes be foundor sometimes there is just a patchy cover of peatencrusters.
This community is characteristic of ombroge-nous peats on bogs where certain treatments havegreatly affected the vegetation; grazing and burn-ing have been of greatest significance, but drainingand aerial pollution have also played a part. It iscommonest on blanket mires, where these factorshave contributed both to floristic impoverishmentand to gross erosion of the peats, but is also foundlocally on run-down raised bogs. The Eriophorummire is present mainly between 500 m and 700 mwhere the climate is cold and wet. The peats are generally dry, often showing surface oxidation andwith a pH frequently as low as 3. This communitycan be found locally through northern Britain, andis especially extensive in the southern Pennines.This community has been seen to revert to the veg-etation characteristic of the richer blanket bogcommunity Calluna vulgaris – Eriophorum vagi-natum mire (M19) within 25 years of enclosureand freedom from burning, but in many instances,particularly if intensive grazing or frequent burn-ing have been accompanied by drainage, thedegeneration of the vegetation is perhaps irreversible.
M20 Eriophorum vaginatumblanket and raised mire
M20
Calluna vulgaris, Vaccinium myr-tillus and Empetrum ssp. nigrumoccur frequently. Campylopus para-doxus and Dicranum scopariumalso frequent with occasional patches of peat-encrusting lichens.
M20b
Calluna vulgaris – Cladonia spp.sub-community
Eriophorum vaginatum not com-pletely dominant though, togetherwith E. angustifolium, it is the mostfrequent species. Sub-shrubs scat-tered, sometimes showing localdominance. Bryophytes frequentbut in small amounts. LargerCladonia spp. among shrub stoolsand old Eriophorum tussocks.
Sub-shrubs at most occasional andsparse among abundant Eriophorumvaginatum with an impoverishedbryophyte and lichen flora.
M20a
Species-poor sub-community
Eriophorum vaginatum forms themain vascular bulk, with only scat-tered E. angustifolium, occasionalsub-shrubs and sometimes a littleDeschampsia flexuosa. Ground pre-dominantly bare with scatteredtufts of Campylopus paradoxus,Orthodontium lineare and Calypogeia spp. Lichens typically very sparse.
47
This mire vegetation is dominated by carpets ofSphagnum spp. with scattered herbs and sub-shrubs forming extensive lawns or the drier partsof hummock and hollow complexes. The domi-nant Sphagnum is usually S. papillosum. Sphag-num auriculatum or S. recurvum (and occasional-ly both) are frequently encountered and less oftenS. cuspidatum. Locally, S. magellanicum and S.pulchrum may be present. Sphagnum compactumis almost always absent in contrast with Ericatetralix – Sphagnum compactum wet heath (M16).Only a few other mosses occur and they are gener-ally of low cover, but leafy hepatics are common.Odontoschisma sphagni and Kurzia pauciflora are most common, but Cladopodiella fluitans,Cephalozia macrostachya, C. connivens, C. bicus-pidata and Calypogeia fissa have also been record-ed. Lichens are typically sparse, but hummocktops can be a habitat for Cladonia impexa,C. arbuscula and C. uncialis.
The vascular plant species present provide themajor distinction between this community andother types of Erico – Sphagnion bogs (M17-M20).Eriophorum vaginatum and Scirpus cespitosusare rare, but Eriophorum angustifolium and
Narthecium ossifragum are constant and oftenabundant. Molinia caerulea is typical, but is oftenweak and not tussock-forming, and Rhynchosporaalba is characteristic of one sub-community, beingmost prominent around hollows and pools. The sub-shrubs Erica tetralix and Calluna vulgarisare very frequent, forming an open canopy. More restricted but conspicuous when present is Myrica gale. Other plants are generally present asscattered individuals, Drosera rotundifolia beingthe most frequent.
This is a community of permanently water-logged, acid and oligotrophic peats, especiallycharacteristic of valley mires maintained by alocally high water table. The peat on which thiscommunity is found is usually not very deep (20-150 cm) with a surface pH mostly in the range of3.5-4.5, and a water table at or very close to thesurface. It is found locally in the southern low-lands of Britain.
Neither burning nor grazing are important inmaintaining this community, as the wetness of thevegetation gives its some protection from thesetreatments, but both can cause damage if com-bined with drainage. With continued autogenicaccumulation of peat, it would probably progressnaturally to some kind of woodland but thisprocess is likely to be very slow in the absence ofdrainage.
M21 Narthecium ossifragum –Sphagnum papillosum valley mire
M21
Rhynchospora alba very frequentand Myrica gale occasional, sometimes abundant in theSphagnum carpet, which is usually dominated by mixtures of S. papillosum and S. auriculatum,with S. recurvum scarce.
M21a
Rynchospora alba – Sphagnumauriculatum sub-community
In this, the most frequentlydescribed M21 community, theSphagnum carpet is generally dominated by mixtures of S. papillosum and S. auriculatum.Hepatics are varied and often abundant. All vascular constantshave a high frequency and in addi-tion Rhynchospora alba is very frequent. Myrica gale frequentlyshows local abundance.
This sub-community is best represented in central southernEngland.
M21b
Vaccinium oxycoccos – Sphagnumrecurvum sub-community
Sphagnum papillosum is oftenabundant but somewhat patchy and S. recurvum frequently has an equal cover. S. auriculatum is much reduced in frequency.Odontoschisma sphagni occurssometimes but hepatics are greatlyreduced. Among vascular plants Rhynchospora alba is scarce and Vaccinium oxycoccos reduced infrequency.
This sub-community extends intothe north and west of England andWales.
Rhynchospora alba and Myrica galerather infrequent, but Vacciniumoxycoccos patchily present andPotentilla erecta occasional in acarpet usually dominated bySphagnum recurvum with some S. papillosum but little S. auriculatum.
48
This community shows considerable variation inits floristic composition which often reflects aunique and complex history of mowing and grazing management. The most prominent struc-tural element typically consists of rushes andsedges of moderate stature, appearing as a ranksward if it is not grazed. Juncus subnodulosus isthe most important of the bulkier species and themost usual dominant. Juncus inflexus and J. artic-ulatus are the commonest accompanying rushes.Of the sedges, the most striking are Carex acuti-formis and C. disticha, either of which can be fre-quent or occasionally dominant. Much more occa-sionally C. elata or C. paniculata can occur. Insummer this rush and sedge layer can be overtopped by flowering dicotyledons. The mostfrequent of these throughout the community areCirsium palustre, Filipendula ulmaria, Angelicasylvestris, Succisa pratensis, Eupatorium canna-binum and Scrophularia aquatica. More locallyLythrum salicaria, Lysimachia vulgaris, Valerianaofficinalis, Thalictrum flavum and Symphytumofficinale can be found, and, in Broadland, thenationally rare Peucedanum palustre. However,grazing may keep these species severely in check.
Among smaller species, grasses are important,and species found include Holcus lanatus,Festuca rubra and, less commonly, Arrhena-therum elatius, together with Poa trivialis,Agrostis stolonifera, Anthoxanthum odoratumand Briza media. Smaller herbs are those charac-teristic of moist grasslands, the commonest being
Mentha aquatica, Caltha palustris, Equisetumpalustre, Carex panicea, Valeriana dioica, Hyper-icum tetrapterum, Hydrocotyle vulgaris, Lotusuliginosus, Lychnis flos-cuculi, Cardamine praten-sis, Ranunculus acris, Potentilla erecta, Cerastiumfontanum, and Rumex acetosa, with severalscrambling plants including Galium uliginosum,G. palustre, Vicia cracca and Lathyrus pratensis.Bryophytes play a reduced role with onlyCalliergon cuspidatum and Brachythecium rutab-ulum being common throughout.
This community brings together secondary herbaceous vegetation developed over a variety ofmoist, base-rich and moderately mesotrophicpeats in southern lowland Britain. It can be foundeither in, or around, well-developed springs,flushes and mires, or marking out more ill-definedareas of influence of surface or ground waters.This community marks out soils which are keptmoist for most of the year and have a moderate tohigh base-status, and usually a pH range of 6.5-7.5.The community has a wide distribution throughthe southern British lowlands with particular con-centrations of stands in East Anglia, northBuckinghamshire and Anglesey.
This community is always dependent on vari-ous kinds of treatment for its maintenance, as it isderived from other wetland vegetation types bymowing or grazing, or both. The reduction in graz-ing results in the expansion of bulky dominantsand ranker grasses and the overwhelming of thesmaller herbs. Its overall distribution and theextent of the stands has become much less thanformerly because of intensive land improvementand abandonment of traditional agricultural practices.
M22 Juncus subnodulosus –Cirsium palustre fen-meadow
49
Sp
ecie
s li
sted
op
pos
ite
at m
ost
occa
sion
al a
nd
har
dly
eve
r ab
un
dan
t.
Jun
cus
subn
odu
losu
s u
sual
ly d
omin
ant
in r
ath
er r
ank
and
im
pov
eris
hed
ve
geta
tion
wit
h b
ulk
ier
gras
ses
abu
nd
ant.
M
olin
ia c
aeru
lea
and
dic
otyl
edon
s li
sted
op
pos
ite
infr
equ
ent
at m
ost. M
22a
Typ
ical
su
b-co
mm
un
ity
In t
his
, th
e m
ost
com
mon
kin
d o
f fe
n-m
ead
ow, t
her
e ar
e n
o p
refe
ren
tial
flor
isti
c fe
atu
res
and
th
e ge
ner
alim
pre
ssio
n i
s of
ran
k st
ruct
ure
an
dim
pov
eris
hm
ent.
Ju
ncu
s su
bnod
ulo
sus
is f
requ
ent
and
th
e co
mm
ones
t d
omin
ant.
Th
e co
mm
ones
t as
soci
ates
are
bulk
ier
gras
ses
such
as
Hol
cus
lan
atu
s,F
estu
ca r
ubr
a,so
met
imes
M
olin
ia c
aeru
lea,
mat
-for
mer
s su
ch a
s A
gros
tis
stol
onif
era
and
Poa
tri
vial
is,
and
tal
ler
dic
otyl
edon
s su
ch a
s C
irsi
um
pal
ust
re,F
ilip
end
ula
ulm
aria
,An
geli
casy
lves
tris
,Su
ccis
a p
rate
nsi
s an
dE
up
ator
ium
can
nab
inu
m. T
her
e ar
eal
so s
pra
wli
ng
pla
nts
an
d a
few
sh
orte
rsp
ecie
s su
ch a
s M
enth
a aq
uat
ica
and
Equ
iset
um
pal
ust
re. W
ith
in t
his
gen
eral
fram
ewor
k th
ere
is c
onsi
der
able
loc
alva
riat
ion
.
Th
is s
ub-
com
mu
nit
y is
th
e m
ost
freq
uen
t ty
pe
of s
pri
ng-
fed
sta
nd
s.
M22
b
Bri
za m
edia
– Tr
ifol
ium
spp
. su
b-co
mm
un
ity
In c
omp
aris
on t
o M
22a,
in
th
is s
ub-
com
mu
nit
yth
e ru
sh a
nd
sed
ge t
ier
has
a l
ower
cov
er a
nd
den
sity
an
d t
her
e is
a r
ich
er a
ssoc
iate
d f
lora
.Ta
ller
dic
otyl
edon
s su
ch a
s C
irsi
um
p
alu
stre
,Fil
ipen
du
la u
lmar
ia,A
nge
lica
sylv
estr
is,E
up
ator
ium
can
nab
inu
m a
nd
S
ucc
isa
pra
ten
sis
show
an
in
crea
sed
fr
equ
ency
an
d o
ften
occ
ur
wit
h C
enta
ure
an
igra
an
d R
um
ex a
ceto
sa. T
he
low
er s
war
d i
sp
arti
cula
rly
rich
. Th
ere
is a
ran
ge o
f gr
asse
s,of
ten
wit
h C
arex
pan
icea
an
d o
ccas
ion
ally
C
. nig
ra a
nd
C. f
lacc
a. T
her
e is
a v
arie
ty o
fot
her
her
bs; m
ost
freq
uen
t ar
e Lo
tus
uli
gin
osu
s,Ly
chn
is f
los-
cucu
li,C
alth
a p
alu
stri
s,R
anu
ncu
lus
acri
s,V
aler
ian
a d
ioic
a,P
oten
till
a er
ecta
,P. a
nse
rin
a an
d H
yper
icu
mte
trap
teru
m w
hic
h a
re c
har
acte
rist
ic o
f M
22 a
sa
wh
ole.
Str
ongl
y p
refe
ren
tial
are
th
e sp
ecie
sli
sted
abo
ve t
oget
her
wit
h P
run
ella
vu
lgar
is,
Ran
un
culu
s re
pen
s,Tr
iglo
chin
pal
ust
re,
Rh
inan
thu
s m
inor
an
d D
acty
lorh
iza
fuch
sii.
Ph
ragm
ites
au
stra
lis
is g
ener
ally
sca
rce.
Th
is s
ub-
com
mu
nit
y is
mos
t fr
equ
entl
y d
evel
oped
aro
un
d g
raze
d s
pri
ng-
fen
s an
d w
etfi
eld
hol
low
s an
d o
ccu
rs t
hro
ugh
th
e ra
nge
of
M22
.
Jun
cus
subn
odu
losu
s of
ten
acc
omp
anie
d b
y J.
in
flex
us
and
J. a
rtic
ula
tus;
als
o C
arex
dis
-ti
cha
and
Des
cham
psi
a ce
spit
osa
pat
chil
y ab
un
dan
t.
Mol
inia
cae
rule
a,B
riza
med
ia a
nd
An
thox
anth
um
od
orat
um
com
mon
at
low
cove
r w
ith
fre
quen
t re
cord
s fo
r C
ard
amin
ep
rate
nsi
s,C
eras
tiu
m f
onta
nu
m,T
rifo
liu
mre
pen
s,T.
pra
ten
se,R
um
ex a
ceto
sa,P
lan
tago
lan
ceol
ata
and
Ep
ilob
ium
par
vifl
oru
m.
Ph
ragm
ites
au
stra
lis,
Lyth
rum
sal
icar
iaan
d H
ydro
coty
le v
ulg
aris
fre
quen
t, w
ith
C
arex
acu
tifo
rmis
or
C. e
lata
com
mon
,so
met
imes
abu
nd
ant.
M22
c
Ca
rex
ela
tasu
b-co
mm
un
ity
Car
ex e
lata
is
un
com
mon
in
fen
-m
ead
ow v
eget
atio
n b
ut
her
e it
occ
urs
wit
h s
ome
abu
nd
ance
an
d o
ccas
ion
ally
is c
o-d
omin
ant
wit
h J
un
cus
subn
odu
lo-
sus.
Ph
ragm
ites
au
stra
lis
is o
ften
p
rese
nt
and
th
ere
is u
sual
ly s
ome
Hyd
roco
tyle
vu
lgar
is. T
he
pla
nts
lis
ted
abov
e ar
e p
refe
ren
tial
. Som
e st
and
sh
ave
Ped
icu
lari
s p
alu
stri
s,M
enya
nth
estr
ifol
iata
,Ran
un
culu
s fl
amm
ula
,R
. lin
gua
and
Ber
ula
ere
cta.
Gra
sses
and
sm
alle
r h
erbs
of
M22
b ar
e p
arti
cula
rly
spar
se.
Th
is a
nd
th
e Ir
issu
b-co
mm
un
ity
are
esp
ecia
lly
wel
l-re
pre
sen
ted
on
to
pog
enou
s m
ires
in
Eas
t A
ngl
ia.
M22
d
Iris
pse
ud
aco
rus
sub-
com
mu
nit
y
Jun
cus
subn
odu
losu
s is
dom
inan
t, b
ut
as i
n M
22c,
Ph
ragm
ites
au
stra
lis
and
Hyd
roco
tyle
vu
lgar
is a
re o
ften
pre
sen
tan
d M
enya
nth
es t
rifo
liat
a,P
oten
till
ap
alu
stri
s an
d E
quis
etu
m f
luvi
atil
eoc
casi
onal
. Gra
sses
an
d s
mal
ler
her
bsch
arac
teri
stic
of
M22
b ar
e sp
arse
.C
arex
ela
ta i
s oc
casi
onal
an
d t
uss
ocks
of C
. pan
icu
lata
are
som
etim
es
pro
min
ent.
Tal
l d
icot
yled
ons
are
pro
min
ent
in s
um
mer
; Cir
siu
m
pal
ust
re,F
ilip
end
ula
ulm
aria
,An
geli
casy
lves
tris
an
d S
ucc
isa
pra
ten
sis
are
all
com
mon
an
d I
ris
pse
ud
acor
us,
Ran
un
culu
s fl
amm
ula
,Val
eria
na
offi
cin
alis
,Lys
imac
hia
vu
lgar
isan
d T
hal
ictr
um
fla
vum
are
all
fre
quen
t.
Th
is a
nd
th
e C
arex
su
b-co
mm
un
ity
are
esp
ecia
lly
wel
l-re
pre
sen
ted
on
to
pog
enou
s m
ires
in
Eas
t A
ngl
ia.
Jun
cus
subn
odu
losu
s u
sual
ly d
omin
ant
wit
h l
ittl
e or
no
Car
ex e
lata
, bu
t w
ith
freq
uen
t an
d s
omet
imes
abu
nd
ant
C. a
cuti
form
is. G
aliu
m p
alu
stre
co
mm
on b
ut
oth
er a
ssoc
iate
s li
sted
opp
osit
e ra
re.
M22
Car
ex e
lata
con
stan
t an
d s
omet
imes
abu
nd
ant
amon
g Ju
ncu
s su
bnod
ulo
sus,
wit
h f
requ
ent
Pot
enti
lla
pal
ust
ris,
Ep
ilob
ium
pal
ust
re,E
quis
etu
m
flu
viat
ile
and
Dac
tylo
rhiz
a in
carn
ata.
50
This vegetation is ill-defined and characterised bythe abundance of either Juncus effusus or J. acuti-florus, sometimes both, in a ground of mesophyticherbs common in moist agricultural grassland.The rushes often have a high cover but they mayalso be more sparse. Juncus effusus is more abun-dant in the east, while J. acutiflorus has a distinct-ly western distribution. Diversity in dominants isnot great but the associates are quite diverse, mak-ing the bounds of this vegetation type hard to fix.Sometimes J. articulatus may be locally frequentand abundant. Holcus lanatus is the most frequentgrass, but Agrostis canina ssp. canina, A. stolon-ifera, Anthoxanthum odoratum and Poa trivialisare also common in drier stands. Festuca rubraand Agrostis capillaris may also become frequent.Molinia caerulea is increasingly common andabundant towards the west and there may be somesedges in the sward. There is a variety of commonherbs. Among the taller species Cirsium palustreis the commonest, Rumex acetosa, Angelicasylvestris and Epilobium palustre are frequent,and two sprawling species Galium palustre andLotus uliginosus are constant. Frequent smallerspecies are Mentha aquatica, Ranunculus flam-mula, R. repens, R. acris, Cardamine pratensis,
Hydrocotyle vulgaris, Viola palustris, and Stellariaalsine.
Bryophytes are variable in their cover. Wherethe vegetation is open they may be abundant.Calliergon cuspidatum is the most frequent, oftenoccurring with Brachythecium rutabulum andRhytidiadelphus squarrosus.
This rush-pasture occurs over a variety ofmoist, moderately acid to neutral, peaty and min-eral soils in the cool and rainy lowlands of west-ern Britain. It is a community of gently-slopingground around the margins of soligenous flushes,as a zone around topogenous mires and wetheaths, and especially widespread in ill-drained,comparatively unimproved or reverted pasture. Itcan be found on a variety of moderately acid toneutral soils that are kept moist to wet for most ofthe year with a pH in the range of 4-6. It is foundat the opposite climatic and edaphic extreme tothe Juncus subnodulosus – Cirsium palustre fenmeadow (M22) with a distinctly oceanic distribu-tion. The community is wide-spread through thewest of Britain from Devon and Cornwall to Skyeand Caithness.
This community is maintained mainly by graz-ing and more occasionally mowing which pre-vents the succession of the community to wood-land. Draining and other kinds of soil improve-ments such as fertilising and reseeding havereduced its former extent.
M23 Juncus effusus/acutiflorus –Galium palustre rush-pasture
51
M23
M23a
Juncus acutiflorus sub-community
Juncus acutiflorus and J. effususare both constant, J. articulatusis locally prominent and J. con-glomeratus is occasional. The com-monest grasses are Holcus lanatusand, preferential here, Moliniacaerulea. Community herbs such asCirsium palustre, Rumex acetosaand Angelica sylvestris remain fre-quent with Galium palustre andLotus uliginosus. Filipendulaulmaria is more common than inM23b and there may be an abun-dance of taller herbs. In the lowertier of vegetation, Mentha aquatica,Cardamine pratensis, Ranunculusflammula and R. repens are frequent with at least some of the herbs listed above.
This, the more sharply-defined sub-community, prevails inScotland and is common in Wales.
M23b
Juncus effusus sub-community
This sub-community is less well-defined and is essentially atransition between M23a and the Holcus lanatus – Juncus effususrush-pasture (MG10). Other rushescomprise Juncus articulatus andJ. conglomeratus, but J. inflexus,common in MG10, is absent.Molinia caerulea is infrequent, but grasses are important in thesward. Where the community issurrounded by improved pasture, as is common, Cynosurus cristatusand Lolium perenne can be presentat low cover. Good distinguishing features are the high frequencies of Galium palustre, Cirsium palustre,Ranunculus flammula and Menthaaquatica.
This is the typical sub-communityof the South-West Peninsula, but is also found through the range of M23.
Juncus effusus constant and usuallydominant, with J. acutiflorusscarce. Holcus lanatus common,but Molinia caerulea and dicotyledons listed opposite all scarce.
Juncus effusus very common, butexceeded by J. acutiflorus, with Molinia caerulea and Holcus lanatus frequent and sometimesabundant. Filipendula ulmariaoccasional, also some of Ranunculus acris, Potentilla erecta,Achillea ptarmica and Equisetumpalustre and locally prominent tall-fen herbs such as Lythrum salicaria and Iris pseudacorus.
52
This community includes the bulk of the Moliniacaerulea vegetation in the lowland south-east ofBritain. Molinia is always the dominant to theextent that associates may be reduced to scatteredindividuals of only a few species. Often howeverthere are a considerable number of associates. Instructural terms the most important species areother monocotyledons. Through most of the central and eastern part of the range where thiscommunity is often found in association withfens, Juncus subnodulosus is the characteristicrush with J. articulatus and J. inflexus sometimesalso present. To the south and west where thecommunity often develops among heath vegeta-tion, J. acutiflorus and J. conglomeratus becomefrequent.
The associated flora of dicotyledons helps to distinguish this community, although it is oftendifficult to separate it from Juncus subnodulosus –Cirsium palustre fen meadow (M22) and Juncuseffusus/acutiflorus – Galium palustre rush pasture(M23) when these contain Molinia. Cirsium palus-tre and Angelica sylvestris are both very frequentand Filipendula ulmaria and Centaurea nigracan also be common. More strictly limited areValeriana dioica, Succisa pratensis, and Cirsiumdissectum, although only the last species is pref-erential. Other common species of wide occur-rence are Potentilla erecta, Lotus uliginosus,
Mentha aquatica, Prunella vulgaris, Ranunculusacris, Hydrocotyle vulgaris, and the scramblersVicia cracca and Lathyrus pratensis.
Coarser grasses are often prominent, withHolcus lanatus and Anthoxanthum odoratummost frequent and Festuca rubra, Deschampsia cespitosa and Agrostis stolonifera less common,though sometimes abundant. There can also besome sedges present, the most common beingsmaller species such as Carex panicea, which is acommunity constant, and less frequent C. hostianaand C. pulicaris. Bryophytes are generally few andof low cover.
This is a community of moist to fairly dry peatsand peaty mineral soils which are circumneutral,generally having a pH within the range 5-6.5. Itcan be found in association with both soligenousand topogenous mires, typically marking out thebetter-drained fringes of bogs and fens, or the mar-gins of wet hollows and flushes. This communityis widespread through the lowland south ofBritain but has become increasingly local withchanges in agricultural practice.
Although climate and soil together both influence the floristics of this community it isessentially a secondary vegetation type, derivedfrom a variety of wetland vegetation types andmaintained by mowing or grazing. In the absence of any kind of treatment all the stands ofthe community would probably progress to scrub or woodland. It has been reduced in extentby agricultural reclamation. Other stands havebecome rank and scrubby with neglect.
M24 Molinia caerulea – Cirsiumdissectum fen-meadow
53
Jun
cus
subn
odu
losu
s ab
sen
t, b
ut
J. a
cuti
flor
us
and
J. c
ongl
omer
atu
sco
mm
on, J
. eff
usu
s oc
casi
onal
. Sp
ecie
sli
sted
op
pos
ite
all
scar
ce b
ut
Eri
cate
tral
ix,C
allu
na
vulg
aris
,Gal
ium
pal
ust
re a
nd
Dac
tylo
rhiz
a m
acu
lata
freq
uen
t.
M24
c
Jun
cus
acu
tifl
oru
s–
Eri
ca t
etra
lix
sub-
com
mu
nit
y
Ru
shes
are
a c
omm
on f
eatu
re, m
ost
usu
ally
Ju
ncu
s ac
uti
flor
us
and
J. c
on-
glom
erat
us.
T
her
e is
fre
quen
tly
som
eE
rica
tet
rali
x, l
ess
ofte
n C
allu
na
vul-
gari
s an
d U
lex
gall
ii, s
o th
at t
he
vege
ta-
tion
loo
ks m
ore
like
a h
eath
. H
owev
erH
olcu
s la
nat
us,
An
thox
anth
um
od
ora-
tum
, les
s of
ten
Fes
tuca
ru
bra
and
Agr
osti
s st
olon
ifer
a ar
e in
term
ixed
wit
h
Mol
inia
cae
rule
a w
ith
fre
quen
t C
arex
p
anic
ea a
nd
a r
ange
of
smal
l h
erbs
.V
aler
ian
a d
ioic
a,C
enta
ure
a n
igra
an
dF
ilip
end
ula
ulm
aria
an
d t
he
tall
-fen
her
bs o
f M
24a
are
not
rep
rese
nte
d.
Bry
oph
ytes
are
not
con
spic
uou
s,th
ough
a n
um
ber
of s
pec
ies
hav
e be
en r
ecor
ded
.
Th
is i
s th
e m
ost
usu
al t
ype
of M
24 i
n
sou
th-w
este
rn B
rita
in.
Mol
inia
cae
rule
a ge
ner
ally
dom
inan
tw
ith
Ju
ncu
s su
bnod
ulo
sus
com
mon
and
fre
quen
t re
cord
s fo
r so
me
of
Val
eria
na
dio
ica,
Gal
ium
uli
gin
osu
m,
Cen
tau
rea
nig
ra,V
icia
cra
cca,
Fil
ipen
du
la u
lmar
ia a
nd
E
quis
etu
m p
alu
stre
.
M24
a
Eu
pa
tori
um
ca
nn
ab
inu
msu
b-co
mm
un
ity
On
e of
th
e m
ost
con
spic
uou
s sp
ecie
sh
ere,
eve
n w
hen
sp
arse
, is
Ph
ragm
ites
aust
rali
s.T
he
best
sin
gle
pre
fere
nti
al
is E
up
ator
ium
can
nab
inu
m w
hic
h
pro
vid
es c
onti
nu
ity
wit
h t
all-
her
b fe
n;
less
com
mon
are
Lyt
hru
m s
alic
aria
and
Lys
imac
hia
vu
lgar
is. C
irsi
um
pal
ust
re,A
nge
lica
syl
vest
ris
and
F
ilip
end
ula
ulm
aria
are
als
o co
mm
onan
d, a
s re
ed o
r se
dge
cov
er b
ecom
esth
inn
er, p
lan
ts s
uch
as
Su
ccis
a p
rate
nsi
s,C
irsi
um
dis
sect
um
,C
enta
ure
a n
igra
an
d E
quis
etu
m
pal
ust
re i
ncr
ease
in
fre
quen
cy.
B
ryop
hyt
es c
an b
e m
ore
con
spic
uou
s in
th
is s
ub-
com
mu
nit
y, b
ut
spec
ies
are
only
few
, wit
h C
amp
yliu
m s
tell
atu
m
join
ing
Cal
lier
gon
cu
spid
atu
man
d B
rach
yth
eciu
m r
uta
bulu
mas
a d
isti
nct
ive
pre
fere
nti
al.
Th
is s
ub-
com
mu
nit
y is
mai
nly
co
nfi
ned
to
Eas
t A
ngl
ia.
M24
b
Typ
ical
su
b-co
mm
un
ity
Mol
inia
cae
rule
a is
oft
en f
oun
d w
ith
smal
ler
amou
nts
of
Jun
cus
subn
odu
lo-
sus
or J
. art
icu
latu
s.S
mal
ler
gras
ses
are
wel
l re
pre
sen
ted
; Hol
cus
lan
atu
s an
dA
nth
oxan
thu
m o
dor
atu
m a
re f
requ
ent
and
Bri
za m
edia
is
stro
ngl
y p
refe
ren
-ti
al. S
edge
s ar
e co
mm
on w
ith
Car
exp
anic
ea a
nd
C. h
osti
ana
show
ing
ap
eak
of o
ccu
rren
ce, C
. pu
lica
ris
esp
e-ci
ally
fre
quen
t an
d C
. nig
ra p
refe
ren
tial
and
som
etim
es i
n a
bun
dan
ce. S
ucc
isa
pra
ten
sis,
Cir
siu
m d
isse
ctu
m,C
. pal
us-
tre
and
An
geli
ca s
ylve
stri
sar
e al
l ve
ryco
mm
on t
oget
her
wit
h t
he
spec
ies
list
-ed
abo
ve.
Su
b-sh
rubs
are
typ
ical
lysp
arse
an
d b
ryop
hyt
es a
re p
oorl
y re
pre
sen
ted
.
Th
is i
s th
e m
ost
com
mon
su
b-co
mm
u-
nit
y in
cen
tral
an
d e
aste
rn E
ngl
and
.
Eu
pat
oriu
m c
ann
abin
um
an
d
Ph
ragm
ites
au
stra
lis
only
occ
asio
nal
. C
lad
ium
mar
iscu
s an
d L
yth
rum
sa
lica
ria
usu
ally
abs
ent.
M24
Ph
ragm
ites
au
stra
lis
con
stan
t,
Cla
diu
m m
aris
cus
quit
e co
mm
on,
both
typ
ical
ly s
ubo
rdin
ate
in c
over
to
Mol
inia
cae
rule
a. E
up
ator
ium
can
nab
inu
m a
nd
Lyt
hru
m s
alic
aria
fr
equ
ent.
M25 Molinia caerulea –Potentilla erecta mire
54
Molinia caerulea is the most abundant speciesfound in this community The associated flora ispoor, and most common are rushes and a fewdicotyledons. Among the former, Juncus acutiflorus and J. effusus are the most frequent.Juncus articulatus and J. subnodulosus are bothoccasional, and J. conglomeratus is very scarce.The only constant dicotyledon is Potentilla erecta.Lotus uliginosus, Succisa pratensis, Cirsiumpalustre and Angelica sylvestris are sparse andoccasionally there can be some Eupatoriumcannabinum or Filipendula ulmaria. Cirsium dis-sectum is very rare and its presence separates theMolinia caerulea – Cirsium dissectum mire (M24)from this community. Also, since the soil pH isgenerally acidic, plants such as Carex hostiana,C. pulicaris and Briza media, frequent in M24, areof very limited occurrence here. Occasionally sub-shrubs can be quite common, particularly Callunavulgaris and Erica tetralix. Ulex gallii can also beoccasional in Wales and south-west England, andU. europaea occurs in some stands. Myrica gale islocal but can be quite extensive and dense.
Grasses are limited in importance but Agrostis canina and A. stolonifera can be found at low
frequency throughout and Holcus lanatus is fairlycommon. Among the dense herbage, bryophytesare sparse.
This mire is a community of moist, but well-aerated, acid to neutral peats and peaty mineralsoils in the wet and cool western lowlands ofBritain. It occurs over gently-sloping ground,marking out seepage zones and flushed marginsof sluggish streams, water-tracks and topogenousmires, but also extends onto the fringes ofombrogenous mires. Soil and drainage conditionsof this community have similarities to those ofM23 and M24 and geographically this communi-ty can be seen as a northern/western replacementof M24. It is especially frequent in south-westEngland, Wales, and southern Scotland.
Although both climate and soils influence thecomposition of the vegetation, treatments such asburning, grazing and drainage are likely to belargely responsible for the development of thiscommunity over ground that would naturallycarry some other kind of mire or wet heath vegeta-tion. Tracts of this community have been replacedby coniferous plantations, particularly in theupland fringes of the north-west. Elsewhere in thelowlands, other tracts of the community togetherwith neighbouring vegetation have been lost to agricultural improvements.
55
M25
c
An
geli
ca s
ylve
stri
ssu
b-co
mm
un
ity
Th
is i
s th
e m
ost
loca
l su
b-co
mm
un
ity,
but
also
th
e m
ost
stri
kin
g su
b-co
mm
un
ity,
dev
elop
ed o
n m
oist
gro
un
dw
ith
fre
edom
fro
m g
razi
ng.
M
olin
iaca
eru
lea
is v
igor
ous,
bu
t va
rieg
ated
by
clu
mp
s of
Ju
ncu
s ac
uti
flor
us
and
J.
eff
usu
s. T
alle
r d
icot
yled
ons
are
com
mon
: Su
ccis
a p
rate
nsi
s an
d
Lotu
s u
ligi
nos
us
are
not
able
tog
eth
erw
ith
th
e p
refe
ren
tial
sp
ecie
s li
sted
abov
e an
d a
lso
Pu
lica
ria
dys
ente
rica
,V
aler
ian
a of
fici
nal
is a
nd
Cen
tau
rea
nig
ra. S
hor
ter
spec
ies
incl
ud
e M
enth
aaq
uat
ica,
Car
dam
ine
pra
ten
sis
and
Equ
iset
um
pal
ust
re w
ith
fre
quen
t G
aliu
m p
alu
stre
. Bry
oph
ytes
are
aga
insp
arse
bu
t C
alli
ergo
n c
usp
idat
um
an
d
C. g
igan
teu
m f
orm
sca
tter
ed p
atch
es.
Th
is s
ub-
com
mu
nit
y is
fou
nd
mai
nly
in
sou
th-w
est
En
glan
d a
nd
sou
th-w
est
Wal
es.
Eri
ca t
etra
lix
con
stan
t, C
allu
na
vu
lgar
is a
nd
Myr
ica
gale
qu
ite
freq
uen
t,w
ith
Eri
oph
oru
m a
ngu
stif
oliu
m c
om-
mon
an
d o
ccas
ion
al N
arth
eciu
mos
sifr
agu
m,D
rose
ra r
otu
nd
ifol
ia a
nd
Vac
cin
ium
oxy
cocc
os.
M25
a
Eri
ca t
etra
lix
sub-
com
mu
nit
y
Th
is i
s th
e w
idel
y d
istr
ibu
ted
typ
e of
M25
. M
olin
ia c
aeru
lea
is t
he
dom
inan
tbu
t th
e as
soci
ated
flo
ra i
s sh
ifte
dto
war
ds
that
of
Eri
ca t
etra
lix
wet
hea
ths
(M15
-16)
. Eri
ca t
etra
lix
is s
tron
gly
pre
f-er
enti
al, w
ith
fre
quen
t C
allu
na
vulg
aris
.Ju
ncu
s ac
uti
flor
us
rem
ain
s co
mm
on b
ut
is jo
ined
by
Eri
oph
oru
m a
ngu
stif
oliu
m.
Ap
art
from
sp
arse
An
thox
anth
um
odor
atu
m,F
estu
ca r
ubr
a a
nd
Agr
osti
sca
nin
a, g
rass
es a
re t
hin
an
d t
alle
r h
erbs
are
poo
rly
rep
rese
nte
d. A
mon
g sm
alle
rp
lan
ts, V
iola
pal
ust
ris
and
Hyd
roco
tyle
vulg
aris
are
som
etim
es p
rese
nt,
bu
tw
ith
occ
asio
nal
Nar
thec
ium
ossi
frag
um
,Dro
sera
rot
un
dif
olia
and
Vac
cin
ium
oxy
cocc
os. B
ryop
hyt
esar
e d
isti
nct
ive,
wit
h A
ula
com
niu
mp
alu
stre
, Pol
ytri
chu
m c
omm
un
e,H
ypn
um
jutl
and
icu
m a
nd
Cal
ypog
eia
fiss
a al
l p
refe
ren
tial
. Sp
hag
nu
m s
pp
.ar
e n
otic
eabl
e, f
orm
ing
pat
ches
;S
ph
agn
um
rec
urv
um
an
d S
. au
ricu
la-
tum
are
th
e co
mm
ones
t sp
ecie
s.
Th
is s
ub-
com
mu
nit
y ca
n b
e fo
un
dth
rou
ghou
t th
e ra
nge
of
M25
.
M25
b
An
thox
an
thu
m o
dor
atu
msu
b-co
mm
un
ity
Alt
hou
gh M
olin
ia c
aeru
lea
is s
till
d
omin
ant,
th
e sw
ard
is
shor
ter
and
mor
e va
ried
. Ap
art
from
th
e ru
shes
an
dgr
asse
s m
enti
oned
abo
ve o
ther
ass
oci-
ates
can
be
spar
se. C
allu
na
vulg
aris
an
d U
lex
gall
iiar
e oc
casi
onal
, as
are
U. e
uro
pae
us
and
Ru
bus
fru
tico
sus.
Eri
ca t
etra
lix
and
Myr
ica
gale
are
ver
yu
nco
mm
on. S
ucc
isa
pra
ten
sis,
Lotu
su
ligi
nos
us
and
Cir
siu
m p
alu
stre
are
al
l m
ore
freq
uen
t th
an i
n M
25a
and
Ser
ratu
la t
inct
oria
an
d R
um
ex a
ceto
saar
e w
eakl
y p
refe
ren
tial
, bu
t al
l te
nd
to
be g
raze
d t
o ro
sett
es.
Sm
alle
r h
erbs
and
bry
oph
ytes
are
poo
rly
rep
rese
nte
d.
Th
is s
ub-
com
mu
nit
y is
sca
tter
edth
rou
ghou
t th
e ra
nge
of
M25
bu
t is
p
arti
cula
rly
freq
uen
t in
Wal
es.
Jun
cus
acu
tifl
oru
s an
d o
ccas
ion
ally
J.
eff
usu
s p
atch
ily
pro
min
ent
in a
gras
sy c
omm
un
ity
wit
h f
requ
ent
Hol
cus
lan
atu
s,F
estu
ca r
ubr
a,A
nth
oxan
thu
m o
dor
atu
m,A
gros
tis
cap
-il
lari
s,D
anth
onia
dec
um
ben
s,Lu
zula
mu
ltif
lora
an
d L
. cam
pes
tris
. Eri
cate
tral
ix r
are
but
Cal
lun
a vu
lgar
isis
occ
asio
nal
.
Sp
ecie
s li
sted
op
pos
ite
usu
ally
all
oc
casi
onal
bu
t ta
ll h
erbs
pro
min
ent
amon
g M
olin
ia c
aeru
lea
and
ru
shcl
um
ps,
wit
h f
requ
ent
An
geli
casy
lves
tris
an
d C
irsi
um
pal
ust
re.
Ep
ilob
ium
pal
ust
re,E
up
ator
ium
can
nab
inu
m,F
ilip
end
ula
ulm
aria
,G
aliu
m p
alu
stre
an
d M
enth
a aq
uat
ica
are
occa
sion
al.
Sch
oen
us
nig
rica
ns
can
be
loca
lly
abu
nd
ant.
M25
56
This community is well-defined by a block of constants and frequent companions but alsoshows considerable variation in associated flora.Stands range from swamp to those having a rank,grassy character. Molinia caerulea is almostalways present, being the commonest dominant.Carex nigra is also a constant, often as prominenttufts which can exceed Molinia in cover. Carexpanicea can be abundant and C. pulicaris is com-mon. In stands transitional to swamp, C. approp-inquata or C. rostrata are present. In the Festucasub-community, by contrast, it is taller rushes andgrasses which, with Molinia, form the bulk of thecover. Juncus acutiflorus may form dense patchesand J. conglomeratus and J. articulatus both occuroccasionally.
Hemicryptophyte dicotyledons are an impor-tant structural element among the Molinia, sedgesand rushes. Most frequent are Succisa pratensis,Filipendula ulmaria, Valeriana dioica, Cirsiumpalustre and Caltha palustris together with thenorthern species Crepis paludosa and Trollius
europaeus. Also common are Sanguisorba offici-nalis, Angelica sylvestris, Centaurea nigra, Leon-todon hispidus, Geum rivale and Lychnis flos-cuculi. Less conspicuous, but also frequent, isEquisetum palustre. Potentilla erecta, Ranunculusacris, and Anemone nemorosa are common.Bryophytes are only prominent in exceptionalcases, with Calliergon cuspidatum most frequent.
This is a very local community of moist, moderately base-rich and calcareous peats andpeaty mineral soils in the sub-montane northernPennines. It represents a northern and altitudinalextreme of the richer kind of Molinia – tall herbvegetation. Stands are rare but all occur aroundthe northern Pennine uplands and the LakeDistrict between 250 m and 450 m altitude.
This community is an apparently stable component of topogenous sequences around openwaters and mires, but where it occurs on flushedslopes, grazing often maintains the communityand prevents progression of the community toscrub or woodland. Drainage and sward improve-ment have probably destroyed many smallerstands of this community and contributed to itsvery local distribution.
M26 Molinia caerulea –Crepis paludosa mire
57
Carex nigra often subordinate to Molinia caerulea in more grassy orrushy vegetation, with frequent andabundant Festuca rubra, F. ovina,Holcus lanatus, Briza media,Deschampsia cespitosa, Anthoxanthumodoratum, Juncus acutiflorus andJ. conglomeratus; associates listedopposite all occasional.
M26b
Festuca rubra sub-community
This sub-community appears moregrassy and is usually developed ondrier soils. Molinia caerulea is theusual dominant, forming the bulk of arough sward together with the grasseslisted above. Sedges are also common; Carex nigra and C. panicea can bothshow high cover and C. flaccaand C. pulicaris can be frequent.Rushes are also common; Juncus acutiflorus and J. conglomeratusare preferential and J. articulatusalso occurs. Taller dicotyledons remain frequent, although Sanguisorba officinalis, Angelica sylvestris and Serratula tinctoria are all scarce. Geumrivale, Centaurea nigra and Leontodonhispidus are more common than in M26a.In shorter swards, Prunella vulgaris,Plantago lanceolata and Trifoliumrepens can be found. Bryophytes are often poorly represented, but Calliergon cuspidatum, Pseudo-scleropodium purum and Lophocoleabidentata remain frequent.
This sub-community has a scattereddistribution through the dales along the upland fringes.
Molinia caerulea and Carex nigra bothabundant, with locally prominent C. appropinquata or C. rostrata.Sanguisorba officinalis, Angelicasylvestris, Serratula tinctoria, Galiumpalustre and G. uliginosum all frequent;bryophytes patchy.
M26a
Sanguisorba officinalissub-community
This is generally the less species-richsub-community. Molinia caeruleaand Carex nigra are usually the mostabundant plants, with one or both dominant in a swamp vegetation withlarge sedges as above. Smaller sedgescan also occur, Carex panicea and C. pulicaris being common. Apart from Agrostis stolonifera, grasses are poorlyrepresented and among small herbsonly Potentilla erecta, Ranunculusacris and Anemone nemorosa occurwith any frequency. The most commontall herbs are listed above. Bryophytesare patchy but better-developed than in M26b. Calliergon cuspidatum,Lophocolea bidentata s.l., Thuidiumtamariscinum and Campylium stella-tum are frequent, with Ctenidium molluscum, Plagiochila asplenioides,Campylium elodes and Aulacomniumpalustre being preferential.
This sub-community is found mostextensively at Sunbiggin and Malham Tarns.
M26
58
Although Filipendula ulmaria is frequent andlocally abundant in a variety of vegetation types,in this community it forms the overwhelmingdominant and the only constant. The dominants ofother communities in which it occurs, tall helo-phytes, bulky sedges, rushes and rank grasses are,if present, all subordinate in this community. Inthe deep shade cast by Filipendula only scatteredindividuals or dispersed clumps of other speciesare found. The commonest accompanying tallherbs are Angelica sylvestris, Valeriana officinalisand Rumex acetosa. In the Valeriana – Rumexsub-community they are often accompanied byLychnis flos-cuculi, Succisa pratensis, Geumrivale and sprawling Galium palustre. In theUrtica – Vicia sub-community these species aremore scarce and Urtica dioica is very commonwith Cirsium arvense, Epilobium hirsutum,Eupatorium cannabinum and Vicia cracca. At lowfrequency throughout there can be scatteredLythrum salicaria, Rumex crispus, R. sangui-neus, Epilobium palustre, Equisetum palustre,E. arvense and E. fluviatile.
There are few bulky monocotyledons;Phragmites australis can be common and Phalaris arundinacea is found occasionally. Rushes are few
with Juncus effusus the most common. Moliniacaerulea can also be found occasionally. Amongsmaller dicotyledons there can be Ranunculusrepens, Mentha aquatica, Lotus uliginosus, andCaltha palustris with more occasional Ranun-culus acris, Cardamine pratensis, C. flexuosa,Potentilla anserina, and Polygonum hydropiper.Bryophytes are few in number and of low cover.
This community is typically found where moist,reasonably rich, circumneutral soils occur in situations protected from grazing. It can be found inboth topogenous and soligenous mires and is espe-cially typical of silted margins of slow-movingstreams and soakways, the edges of flushes anddamp hollows, and also of artificial habitats such asalong dykes and roadside ditches and aroundponds. This community occurs throughout lowlandBritain.
Both draining and grazing have reduced theextent of this community to small remnants inmany places. The community cannot tolerateany other than very light or sporadic grazingand so stands often only persist outside enclo-sures, and around unreclaimed mires and flush-es. For example, this community can be foundin wet field bottoms and edges that have beenfenced off, and alongside streams and ditchesbetween pasture and boundaries. Progression towoodland, even in the absence of treatmentssuch as grazing or mowing, appears to be slow.
M27 Filipendula ulmaria –Angelica sylvestris mire
59
Ass
ocia
tes
list
ed o
pp
osit
e at
mos
t oc
casi
onal
bu
t Ju
ncu
s ef
fusu
s an
dH
olcu
s la
nat
us
are
con
stan
t, a
nd
Ju
ncu
s ac
uti
flor
us
and
Mol
inia
cae
rule
aoc
casi
onal
in
ran
ker
swar
ds
wit
hA
nth
oxan
thu
m o
dor
atu
m,A
gros
tis
stol
onif
era,
Men
tha
aqu
atic
a an
dLo
tus
uli
gin
osu
s qu
ite
com
mon
.
M27
c
Jun
cus
effu
sus
– H
olcu
s la
na
tus
sub-
com
mu
nit
y
Fil
ipen
du
la u
lmar
ia i
s st
ill
the
mos
tab
un
dan
t sp
ecie
s, b
ut
oth
er t
all
her
bssu
ch a
s A
nge
lica
syl
vest
ris,
Val
eria
na
offi
cin
alis
,Cir
siu
m p
alu
stre
an
d
Ru
mex
ace
tosa
occ
ur
occa
sion
ally
. O
f gr
eate
r im
por
tan
ce, r
ush
es a
nd
gras
ses
may
hav
e m
oder
ate
abu
nd
ance
. Ju
ncu
s ef
fusu
san
d H
olcu
s la
nat
us
are
both
con
stan
t an
d J
. acu
tifl
oru
san
d
Mol
inia
cae
rule
a oc
casi
onal
, wit
h a
ran
ge o
f ot
her
gra
sses
. In
som
e st
and
s M
enth
a aq
uat
ica
and
Lot
us
uli
gin
osu
sar
e fr
equ
ent.
In
oth
ers
Iris
pse
ud
acor
us
and
/or
Oen
anth
e cr
ocat
a ca
n b
e p
rom
inen
t.
Th
e su
b-co
mm
un
ity
is w
este
rn
in d
istr
ibu
tion
.
M27
a
Va
leri
an
a o
ffic
ina
lis
– R
um
ex a
ceto
sasu
b-co
mm
un
ity
Fil
ipen
du
la u
lmar
ia i
s ab
un
dan
t an
d d
omin
ant.
Th
e ve
geta
tion
may
be
spec
ies-
poo
r, b
ut
over
all
it i
s ch
arac
-te
rise
d b
y a
vari
ety
of a
ssoc
iate
s. M
ost
com
mon
are
An
geli
ca s
ylve
stri
s an
dV
aler
ian
a of
fici
nal
is, b
oth
som
etim
eslo
call
y ab
un
dan
t, w
ith
Ru
mex
ace
tosa
,Ly
chn
is f
los-
cucu
li,S
ucc
isa
pra
ten
sis
and
Geu
m r
ival
e ar
e le
ss c
omm
on.
Am
ong
smal
ler
her
bs c
an b
e th
e sp
ecie
sli
sted
abo
ve w
ith
Ste
llar
ia a
lsin
ean
dA
juga
rep
tan
s an
d G
aliu
m p
alu
stre
as
the
mos
t co
mm
on s
pra
wli
ng
pla
nt.
Ap
art
from
Poa
tri
vial
is, p
refe
ren
tial
her
e, g
rass
es a
nd
ru
shes
are
in
freq
uen
t.C
arex
ros
trat
a is
qu
ite
com
mon
an
d c
anoc
cur
wit
h M
enya
nth
es t
rifo
liat
a an
d
Pot
enti
lla
pal
ust
ris.
Bry
oph
ytes
ar
e be
tter
dev
elop
ed i
n t
his
su
b-co
mm
un
ity,
wit
h B
rach
yth
eciu
m
ruta
bulu
m t
he
mos
t co
mm
on s
pec
ies.
Th
is s
ub-
com
mu
nit
y is
th
e u
sual
for
min
nor
ther
n E
ngl
and
an
d i
n s
outh
ern
and
eas
tern
Sco
tlan
d.
M27
M27
b
Urt
ica
dio
ica
– V
icia
cra
cca
sub-
com
mu
nit
y
Fil
ipen
du
la u
lmar
ia a
nd
a v
arie
ty
of t
all
her
bs a
gain
pro
vid
e th
e m
ain
st
ruct
ura
l el
emen
t. A
nge
lica
syl
vest
ris,
Cir
siu
m p
alu
stre
an
d L
yth
rum
sal
icar
iaar
e oc
casi
onal
, bu
t ot
her
s p
rese
nt
inM
27a,
e.g
. Val
eria
na
offi
cin
alis
an
d
Ru
mex
ace
tosa
, bec
ome
scar
ce o
rab
sen
t. U
rtic
a d
ioic
a, h
owev
er, i
s ve
ryco
mm
on a
nd
is
fou
nd
wit
h o
ccas
ion
al
Eu
pat
oriu
m c
ann
abin
um
an
dE
pil
obiu
m h
irsu
tum
for
min
g p
atch
es.
Sca
tter
ed t
hro
ugh
out
can
be
Cir
siu
mar
ven
se a
nd
Cen
tau
rea
nig
ra.
Ph
ragm
ites
au
stra
lis
can
be
com
mon
;al
tern
ativ
ely
ther
e m
ay b
e tu
ssoc
ks
of A
rrh
enat
her
um
ela
tiu
s an
d s
ome
Hol
cus
lan
atu
s or
sca
tter
ed c
lum
ps
ofru
shes
. S
mal
ler
her
bs a
nd
bry
oph
ytes
are
few
an
d s
par
se.
Th
is s
ub-
com
mu
nit
y is
fou
nd
in
ce
ntr
al, s
outh
ern
an
d e
aste
rn B
rita
in.
An
geli
ca s
ylve
stri
s,V
aler
ian
a of
fici
nal
is,R
um
ex a
ceto
sa,L
ych
nis
fl
os-c
ucu
li,S
ucc
isa
pra
ten
sis
and
Geu
m r
ival
e ar
e co
mm
on a
mon
g ta
ller
asso
ciat
es, w
ith
Cal
tha
pal
ust
ris,
Ran
un
culu
s fl
amm
ula
,R. r
epen
s,R
. acr
is,C
ard
amin
e fl
exu
osa
and
C
. pra
ten
sis
occa
sion
al t
o fr
equ
ent
belo
w a
nd
Gal
ium
pal
ust
re,G
. uli
gi-
nos
um
an
d L
ath
yru
s p
rate
nsi
s cl
imbi
ng
or s
pra
wli
ng.
Ass
ocia
tes
list
ed f
or M
27a
at m
ost
occa
sion
al, b
ut
spar
se P
hra
gmit
es a
us-
tral
is c
omm
on, o
ften
wit
h p
rom
inen
tcl
um
ps
of U
rtic
a d
ioic
a, E
up
ator
ium
can
nab
inu
m a
nd
Ep
ilob
ium
hir
sutu
m.
Th
e sp
raw
lin
g h
erbs
Gal
ium
ap
arin
ean
d V
icia
cra
cca
are
com
mon
.
60
In its typical form this is a luxuriant and species-rich community with Iris pseudacorusmore abundant than Oenanthe crocata, althoughboth are constants, except in the far north ofScotland where O. crocata is not found. Other tallherbs are nearly always present, though onlyLycopus europaeus, Rumex crispus and Scut-ellaria galericulata are frequent throughout thecommunity. Other species such as Rumex acetosa,Lychnis flos-cuculi, Angelica sylvestris, Valerianaofficinalis, Cirsium palustre, C. arvense and Urticadioica are often common and conspicuous butpreferential to particular sub-communities.
Rushes and grasses are frequently important.Juncus effusus and J. acutiflorus are common, asare Poa trivialis and Agrostis stolonifera. There area variety of smaller dicotyledons. Some typicallyoccur as scattered plants, for example Ranunculusacris, Caltha palustris, Stellaria alsine, Menthaaquatica and Hydrocotyle vulgaris, while Ranun-culus repens and Potentilla anserina form matswith high local cover. On patches of wet and openground, annuals may be prolific, such as Poly-gonum hydropiper, Montia fontana, and on cattle-poached mud, Ranunculus sceleratus. On salt-
marsh transitions Atriplex prostrata and Matri-caria maritima may be frequent with Samolusvalerandi, Oenanthe lachenalii and halophyticherbs. Bryophytes are few, with Eurhynchiumpraelongum being the commonest throughout.
This community is confined to moist, more nutrient-rich soils along the oceanic seaboard ofBritain. It is especially characteristic of the fresh-water seepage zone along the upper edge of salt-marshes in the sheltered sea-lochs of westernScotland. Other situations in which it occurs areover stabilised shingle down the west coast andin wetter hollows and flushes on raised beach platforms and gentle cliff slopes. The communityis the oceanic counterpart of the Filipendulaulmaria – Angelica sylvestris mire (M27) and islargely confined to the west coast of Britain. Inparticular it is found in west Scotland fromOrkney and Shetland southwards, with scatteredstands in south-west England and west Wales.
The community was probably once much morewidespread in south-west England and west Walesbut it may have been largely destroyed in its salt-marsh habitat by human interference with the tran-sitional upper zones. The community, where itdoes occur, is often not heavily grazed and itappears to be a relatively stable vegetation typewith only a slow progression to scrub or woodland.
M28 Iris pseudacorus –Filipendula ulmaria mire
61
Gro
up
s of
sp
ecie
s op
pos
ite,
an
d e
ven
F
ilip
end
ula
ulm
aria
, in
freq
uen
t in
rath
er o
pen
veg
etat
ion
wit
h A
trip
lex
pro
stra
ta a
nd
Sam
olu
s va
lera
nd
i co
m-
mon
an
d s
por
adic
rec
ord
s fo
r m
arit
ime
pla
nts
.
M28
a
Jun
cus
spp
. su
b-co
mm
un
ity
Th
is i
s th
e ri
ches
t su
b-co
mm
un
ity
inw
hic
h o
ther
dic
otyl
edon
s, r
ush
es a
nd
gras
ses
form
a c
onsi
sten
t as
soci
ated
flor
a. I
ris
pse
ud
acor
us
is g
ener
ally
acl
ear
dom
inan
t al
thou
gh b
oth
Oen
anth
ecr
ocat
a an
d F
ilip
end
ula
ulm
aria
can
be
pat
chil
y ab
un
dan
t w
ith
th
e ab
ove
Jun
cus
spp
. Am
ong
the
tall
er h
erbs
,Ly
cop
us
euro
pae
us,
Ru
mex
cri
spu
s,S
cute
llar
ia g
aler
icu
lata
,An
geli
casy
lves
tris
an
d V
aler
ian
a of
fici
nal
is,
wit
h t
he
spec
ies
list
ed a
bove
, all
occ
ur
freq
uen
tly
to o
ccas
ion
ally
. Com
mon
gras
ses
are
Fes
tuca
ru
bra,
Hol
cus
lan
a-tu
s,A
nth
oxan
thu
m o
dor
atu
m,P
oap
rate
nsi
s an
d E
lym
us
rep
ens
form
ing
scat
tere
d t
uss
ocks
, an
d w
ith
Car
exot
ruba
e an
d t
rail
ing
Gal
ium
pal
ust
re.
M28
M28
c
Atr
iple
x p
rost
rata
– S
am
olu
s va
lera
nd
isu
b-co
mm
un
ity
Alt
hou
gh I
ris
pse
ud
acor
us
and
Oen
anth
e cr
ocat
a ca
n b
e ab
un
dan
t,ta
ller
ass
ocia
tes
are
gen
eral
ly l
acki
ng;
even
Fil
ipen
du
la u
lmar
ia i
s sc
arce
an
dLy
cop
us
euro
pae
us
and
Ru
mex
cri
spu
sar
e on
ly p
rese
nt
as s
catt
ered
pla
nts
.A
mon
g sm
alle
r p
lan
ts t
he
com
mon
est
gras
ses
are
Agr
osti
s st
olon
ifer
a an
dF
estu
ca r
ubr
a. T
he
mos
t co
mm
on p
ref-
eren
tial
s ar
e p
lan
ts t
oler
ant
of s
alin
eh
abit
ats,
in
clu
din
g A
trip
lex
pro
stra
ta,
the
mos
t co
mm
on, w
ith
Sam
olu
sva
lera
nd
i,O
enan
the
lach
enal
ii,
Mat
rica
ria
mar
itim
a,Tr
iglo
chin
m
arit
ima
and
Gla
ux
mar
itim
a.
Jun
cus
effu
sus
and
/or
J. a
cuti
flor
us
con
stan
t an
d p
atch
ily
abu
nd
ant
wit
hfr
equ
ent
Ru
mex
ace
tosa
,C
irsi
um
pal
ust
re,
Ep
ilob
ium
pal
ust
re,
Lych
nis
flos
-cu
culi
,R
anu
ncu
lus
acri
s,C
alth
ap
alu
stri
s,Lo
tus
uli
gin
osu
s an
dG
aliu
m p
alu
stre
.
Sp
ecie
s li
sted
op
pos
ite
occa
sion
al a
tm
ost,
bu
t U
rtic
a d
ioic
a an
d C
irsi
um
arve
nse
con
stan
t w
ith
Gal
ium
ap
arin
ean
d o
ccas
ion
al t
o fr
equ
ent
Ely
mu
sre
pen
s,S
tell
aria
med
ia,A
rrh
enat
her
um
elat
ius
and
Dac
tyli
s gl
omer
ata.
M28
b
Urt
ica
dio
ica
– G
ali
um
ap
ari
ne
sub-
com
mu
nit
y
Th
e ve
geta
tion
her
e, a
lth
ough
as
tall
an
d l
uxu
rian
t as
in
M28
a, i
s le
sssp
ecie
s-ri
ch. I
ris
pse
ud
acor
us
is s
till
dom
inan
t an
d b
oth
Oen
anth
e cr
ocat
aan
d F
ilip
end
ula
ulm
aria
rem
ain
fre
-qu
ent,
bu
t ap
art
from
Lyc
opu
s eu
ro-
pae
us
and
Scu
tell
aria
gal
eric
ula
ta,t
he
only
oth
er c
omm
on t
alle
r d
icot
yled
ons
are
Urt
ica
dio
ica
and
Cir
siu
m a
rven
sew
hic
h c
an b
e ab
un
dan
t. O
ther
tal
ler
spec
ies
of M
28a
are
occa
sion
al o
rsc
arce
an
d G
aliu
m a
par
ine
rep
lace
s G
. pal
ust
re. G
rass
es a
re o
ften
con
spic
u-
ous
wit
h P
oa t
rivi
alis
an
d A
gros
tis
stol
onif
era
very
com
mon
as
pat
chy
carp
ets
inte
rsp
erse
d w
ith
th
e ot
her
spec
ies
list
ed a
bove
.
62
M30 Related vegetation of seasonally-inundated habitats
This community has a very distinctive appear-ance, typically consisting of low creeping or float-ing mats of Hypericum elodes and Potamogetonpolygonifolius. Very often, unless the ground hasbeen badly trampled by grazing animals, these twoconstants are set in a carpet of submergedSphagnum auriculatum, sometimes with S. cuspi-datum, S. palustre or S. recurvum. Other bryo-phytes are sparse but Polytrichum commune orAulacomnium palustre, and Drepanocladus exan-nulatus, D. revolvens, and Calliergon cuspidatum,may be locally abundant.
Other vascular plants are scattered. Juncus bulbosus and Ranunculus flammula are the onlyconstants but Hydrocotyle vulgaris, Anagallistenella, Drosera rotundifolia, Narthecium ossi-fragum, and Galium palustre can all be moderately frequent, along with sedges such asCarex demissa, C. echinata, C. panicea and C. nigra. There can also be sparse shoots or smallpatches of Molinia caerulea, Agrostis canina ssp.canina, Juncus articulatus, J. effusus, J. acuti-florus, Eleocharis multicaulis, Eriophorum angus-tifolium and Rhynchospora alba. Carex rostratacan also be found in some stands. Two rare speciesassociated with this community are Galiumdebile, in the New Forest, and the fern Pilulariaglobulifera.
This community is characteristic of shallow soakways and pools in peats and peaty mineralsoils with fluctuating water levels, such as seepages and runnels around mires and in heathland pools, at moderate altitudes. The wateris typically clear, still or gently-flowing, moder-ately acid to neutral, with a pH between 4 and 5.5,and probably quite oligotrophic. This vegetation isconfined to the warm oceanic parts of Britain andextends in a well-defined zone from west Surreythrough the New Forest to the South-WestPeninsula and north through Wales to Galloway. Itmay well be found further north, following thedistribution of Hypericum elodes.
This soakway appears to be a stable vegetationtype in the absence of nutrient enrichment. In situations where there is some nutrient enrich-ment, grazing and trampling may help continuallyset back any tendency to succession. Trampling bygrazing animals can also play a part in keeping thevegetation open and varied, although heavypoaching can be deleterious to the Sphagnum carpet.
No sub-communities.
Other vegetation of the same type as Hypericumelodes – Potamogeton polygonifolius soakway(M29), and characteristic of similar, seasonallyinundated habitats, with rather base-poor andonly moderately enriched waters, has only beenpoorly sampled. Some examples, lackingHypericum elodes but otherwise the same asM29, may be regarded as impoverished stands ofthat community, though it must be noted thatspecies such as Potamogeton polygonifolius,Eriophorum angustifolium, Juncus bulbosus/kochii and Sphagnum auriculatum also occurwith some frequency in bog-pool and poor-fenvegetation.
There are also stands in which Eleocharis multicaulis is strongly dominant with little or noHypericum elodes or Potamogeton polygonifolius;these look similar to the Eleocharitetum multi-caulis recorded from Eire and elsewhere in west-ern Europe. Deschampsia setacea is listed as acharacteristic species of such vegetation, and inBritain this rare species is typical of this type ofhabitat. Scirpus fluitans can also be found domi-nating in swards which lack some of the typical plants of M29, and in the New Forest andCornwall, Baldellia ranunculoides is a frequentand conspicuous component of low-growing vegetation in seasonally wet pools.
All these vegetation types, along with M29,have been grouped in the Hydrocotylo-Baldellionalliance, comprising assemblages of mesotrophicto oligotrophic, and periodically fluctuatingwaters.
No sub-communities.
M29 Hypericum elodes –Potamogeton polygonifoliussoakway
63
In this community Anthelia julacea forms cushions up to a metre or more in thickness andseveral square metres in extent. Its associated florais species-poor and vascular plants are sparse.Among other bryophytes, Sphagnum auriculatum,Marsupella marginata and Scapania undulata areall constant, the first of which can form prominentpatches. Racomitrium lanuginosum and Philonotisfontana are also frequent with occasionalCalliergon sarmentosum, Campylopus atrovirens,Polytrichum commune and Racomitrium fascicu-lare. Rare bryophytes which have been recordedin this community include Anthelia juratzkana,which almost totally replaces A. julacea in somestands, and Pohlia ludwigii.
The commonest vascular plant is Deschampsiacespitosa. Scattered plants of Nardus stricta occurquite often with occasional Narthecium ossi-fragum, Pinguicula vulgaris, Carex demissa, and
Saxifraga stellaris. Less frequent are Eriophorumangustifolium, Carex bigelowii, C. nigra, Festucavivipara, Agrostis canina, A. stolonifera, Juncusbulbosus, Thalictrum alpinum, and Viola palustris.
This is a montane community typical of oftenskeletal mineral and organic soils kept more orless permanently wet by the trickling of acid and oligotrophic waters, of pH 4.5-5.0, frequentlyderived at higher altitudes from snow-melt. Itoccurs at moderate to high altitudes, from about400 m to over 1000 m, marking out areas of lessvigorous seepage among tracts of montane grass-lands and grass-heaths or among snow-bed vegeta-tion. It is a local but widespread community foundthrough much of Scotland, the Lake District and Snowdonia.
Anthelia julacea – Sphagnum auriculatumspring is an essentially stable community in theharsh environment in which it characteristicallyoccurs.
No sub-communities.
M31 Anthelia julacea –Sphagnum auriculatum spring
64
M32 Philonotis fontana –Saxifraga stellaris spring
These bryophyte-dominated springs, flushes andrills are striking in appearance. Philonotis fontana isusually dominant and obvious by its fresh-greencolour. The golden-green Dicranella palustris andScapania undulata are often also abundant. Thesespecies together often form cushions or plush mats.Less consistent but sometimes prominent areSphagnum auriculatum, Scapania uliginosa, Calli-ergon sarmentosum, Drepanocladus exannulatus, D.fluitans and the characteristic, but not very frequent,Jungermannia exsertifolia. Bryum pseudotriquetrumis also common, but not as consistent as in morebase-rich springs, and Cratoneuron commutatumand C. filicinum are scarce.
The associated vascular flora is rather varied incomposition and cover and typically species-poor.The only constant is Saxifraga stellaris, butDeschampsia cespitosa (with ssp. alpina at higheraltitudes) is often found in small quantities withscattered Stellaria alsine. More occasional areFestuca rubra, Anthoxanthum odoratum, Agrostisstolonifera and A. canina, all usually at low cover,with sparse Viola palustris, Nardus stricta, Carexbigelowii and C. panicea. In stands which are perhaps less base-poor, Montia fontana andChrysosplenium oppositifolium become frequentand abundant, along with Caltha palustris,Cardamine pratensis and a number of other associated species.
This is a community of springs and rills at moderate to high altitudes, above 450 m to over1000 m, where there is irrigation with circum-neutral and oligotrophic waters with a pH ofaround 4.5-6. This is one of the most commonand widespread types of spring vegetation in theuplands of north-west Britain and is dependenton sustained and vigorous irrigation by ground-waters, common in the wetter parts of the coun-try. It marks out permanent springs of a well-defined character, also diffuse flushes and seep-age lines, rills and small streams and occasional-ly steep, dripping ground. In some places snow-melt may be an important water source. It isfound on a variety of waterlogged soils from frag-mentary accumulation of silt among stones toflushed peats and gleys. The community is common through the Scottish Highlands, theSouthern Uplands, the Lake District and northWales and over the non-calcareous parts of thePennines. It can also be found as fragmentarystands at lower altitudes without the montaneelement in the vegetation, particularly at thesouthern limit of the range of this community.
The harsh montane environment has a strikinginfluence on the composition of the communityand though stands can be grazed and trampled,climatic and soil conditions probably play themajor part in maintaining the vegetation as aneffective climax. At lower altitudes, it could perhaps show some successional development inungrazed situations.
65
Sphagnum auriculatum and otherbryophytes listed opposite very scarcebut Bryum pseudotriquetrum frequent.Montia fontana and Chrysospleniumoppositifolium constant and sometimesabundant.
M32b
Montia fontana – Chrysospleniumoppositifolium sub-community
Vascular plants are more numerous and varied, although bryophytes stillgenerally have dominance. Philonotisfontana, Dicranella palustris andScapania undulata are all very com-mon and each, especially the first, canbe abundant. Bryum pseudotriquetrumis frequent and Jungermannia exsertifo-lia occasional. Among the vascularplants, Montia fontana andChrysosplenium oppositifolium havehigh frequencies with Saxifraga stel-laris, and are sometimes abundant.Along with Stellaria alsine there areoften very small plants of Caltha palus-tris (ssp. minor) and Cardamine praten-sis. Epilobium palustre can sometimesbe found but more distinctive are thefrequent occurrence of E. alsinifoliumand E. anagallidifolium. Grasses can bequite common; Deschampsia cespitosais often joined by Anthoxanthum odor-atum, Agrostis canina and several othergrasses together with some sedges.
This community is associated with arange of substrates slightly more base-rich than those of M32a.
Sphagnum auriculatum often abun-dant, with Calliergon sarmentosumand Scapania uliginosa occasional andlocally prominent. Montia fontana and Chrysosplenium oppositifoliumvery occasional.
M32a
Sphagnum auriculatumsub-community
In this species-poor sub-community the bryophyte mat consists of mixturesof Philonotis fontana, Scapania undulata and Dicranella palustris withSphagnum auriculatum strongly prefer-ential and often abundant. Calliergonsarmentosum and Scapania uliginosaare occasional and Polytrichum com-mune and Hygrohypnum ochraceumoccur at low frequencies. Among thevascular plants only Saxifraga stellarisand Deschampsia cespitosa are con-stant but other grasses such as Agrostisstolonifera, A. capillaris, Anthoxanthumodoratum and Festuca rubra are quitefrequent as scattered tufts.
This sub-community occurs mainly onthe harder acidic quartzites and sand-stones of the north-west Highlands.
M32
66
This is an open vegetation type with a bryophyte-dominated carpet broken by areas ofwet, silty and stony ground. Scapania undulata,Calliergon sarmentosum and Blindia acuta are all common and each can be abundant, with occa-sional patches of Dicranella palustris, Philonotisfontana, Drepanocladus revolvens, Marsupellaaquatica and Sphagnum auriculatum. Scatteredthrough this and over the rills are plants of Carexdemissa, Koenigia islandica, Deschampsia cespi-tosa, Saxifraga stellaris, Juncus triglumis, J. bulbo-sus and the rare J. biglumis and Sagina saginoides.All these are generally of low cover, though manycan show a measure of abundance and Koenigia,although individual plants are small, can coverquite a large ground area.
This community occurs on ground which iskept periodically moist by circumneutral and oligotrophic waters. Typically it is found in opensilty or stony flushes fed by vigorous seepage fromsprings issuing at moderately high altitudes,over 500 m, from basalt. In their base status,with pH values around 6.0, and their low cationcontent, the waters are similar to those which feedthe Philonotis fontana – Saxifraga stellaris spring community (M32), which often occupies thespring-heads above the flushes. The community isconfined to Skye, where it occurs scattered alongthe Trotternish Ridge extending several kilometresnorth of the Storr. It forms one of several communities in which Koenigia can befound.
No sub-communities.
In this community Pohlia wahlenbergii var.glacialis dominates in spongy carpets of a brightapple-green colour, often of small extent, butexceptionally up to 200 m2. Few other bryophytesoccur with any frequency although P. ludwigii is aconstant. Philonotis fontana can be prominent,although not with the high cover found inPhilonotis fontana – Saxifraga stellaris spring(M32). Other bryophytes recorded occasionallyare Hygrohypnum luridum, Bryum weigelii, Calli-ergon stramineum, Scapania undulata, S. uligi-nosa, Dicranella palustris and Marchantiaalpestris.
In this carpet there are only a few vascular plants.Deschampsia cespitosa (presumably ssp. alpina) andSaxifraga stellaris are constant, but Cerastium ceras-toides is quite often found and there can be Stellariaalsine, Chrysosplenium oppositifolium, Epilobiumanagallidifolium, Veronica serpyllifolia var. humi-fusa, and Rumex acetosa. Other rare plants foundoccasionally are Epilobium alsinifolium, Alopecurusalpinus and Phleum alpinum.
This community is strictly confined to spring-heads associated with late snow-bedswhere there is vigorous irrigation by cold waters.The flushing waters, and often sloppy, ill-struc-tured mixtures of mineral and organic matterbeneath the moss carpet, are base-poor and oligotrophic. Although Pohlia wahlenbergii var.glacialis occurs over quite a range of altitudesthrough the uplands of Wales, Cumbria andScotland, it is only found with the kind of domi-nance characteristic here within the high montanezone at altitudes generally above 850 m. Withinthis area, which includes the central and north-western Highlands of Scotland, the community isfurther restricted to situations where the snow lies longest, especially on north- and east-facingslopes.
The general climatic and edaphic features determine the overall character of this communitywith its cold-tolerant plants and montane species.
No sub-communities.
M33 Pohlia wahlenbergii var.glacialis spring
M34 Carex demissa – Koenigiaislandica flush
67
These rills typically have a rather crowded, thoughnot always continuous, cover of vascular plants andbryophytes. Much of the growth is often submergedin the shallow waters, with a floating or shortlyemergent canopy. Ranunculus omiophyllus is oftenabundant, frequently with Montia fontana. Floatingleaves of Potamogeton polygonifolius are common-ly prominent and there can be local patches ofAgrostis stolonifera, Glyceria fluitans, Juncus bul-bosus, J. articulatus and Callitriche stagnalis, withscattered plants of Ranunculus flammula, a con-stant, Myosotis secunda and Stellaria alsine. Moreoccasional are Ranunculus repens, Equisetumpalustre, Hydrocotyle vulgaris, Galium palustreand Lotus uliginosus. Juncus bufonius and Scirpussetaceus can sometimes be seen on open mud.
Bryophytes can contribute substantially to thecover although there are only a few frequentspecies. Sphagnum auriculatum is a constant andoften grows semi-submerged with patches ofPhilonotis fontana but, apart from occasionalPolytrichum commune, other species are sparse,with only occasional records of Calliergon cuspidatum, C. stramineum, Drepanocladus exan-nulatus, D. vernicosus, Scapania irrigua andRhytidiadelphus squarrosus.
This community is typical of spring-heads andrills at moderate altitudes in south-westernBritain, where there is irrigation by circumneutraland probably quite oligotrophic waters. These aretypically rather base- and nutrient-poor with pHvalues ranging from 4.5 to 6.5 over acidic rocks. Ithas been recorded only from south-westernEngland, Wales, and around the Lake District. Itmay occur throughout the range of R. omiophyllusin Britain.
No sub-communities.
There is a clear contrast, among the Cardamino –Montion springs and flushes of acid to circum-neutral habitats, between the upland communitieswhich have been described, where Montiafontana, Saxifraga stellaris and Philonotis fontanaare conspicuous, and the vegetation of lowlandand often shaded situations. In these, Chryso-splenium oppositifolium occurs with bryophytessuch as Hookeria lucens, Rhizomnium puncta-tum, Trichocolea tomentella, Pellia epiphylla andConocephalum conicum. This type of vegetationhas not been separately sampled here but it figuresin the field and ground layers of various wetwoodlands, notably the Alnus – Carex, Alnus –Urtica and Alnus – Fraxinus – Lysimachia types,where it is distinctive of seepage lines and dampstream banks, quite often with Cardamine flexu-osa, C. amara and Chrysosplenium alternifolium.Similar mixtures of plants can be found widelythrough lowland Britain, especially in the wetterwest and around the upland fringes, along stream-sides and wet banks, probably once wooded, but where shade is now provided by tallherbs or by the aspect of the site. These need further sampling.
No sub-communities.
M35 Ranunculus omiophyllus –Montia fontana rill
M36 Lowland springs andstreambanks of shaded situations
68
Cratoneuron commutatum occurs frequently in avariety of calcareous mires, but here it is consistently dominant in large masses, often forming prominent mounds or banks. In somestands of the same general floristic composition,C. filicinum accompanies or totally replaces it.Other bryophytes can make a contribution, buttypically a minor one. However, the constantBryum pseudotriquetrum is very common.Occasional species include Philonotis fontana, P.calcarea, Aneura pinguis, Pellia endiviifolia,Drepanocladus revolvens, Gymnostomum recurvi-rostrum, G. aeruginosum, Brachythecium rivulareand Dicranella palustris. Very typically there issome tufa deposition allowing the mat to buildinto mounds. The vascular element is typicallyspecies-poor and of low total cover. There may beconsiderable variation in associated flora and, par-ticularly where stands are developed on gently-sloping ground, a richer and more extensive layercan be found, coming close to the Cratoneuroncommutatum – Carex nigra spring (M38). Often,however the only species present are Festucarubra, Cardamine pratensis and Saxifragaaizoides, the last of which is absent from southernScotland and Wales. Occasional herbs includeAgrostis stolonifera, Deschampsia cespitosa,
Equisetum palustre, Chrysosplenium oppositifoli-um, Poa trivialis, Carex panicea, C. nigra and C. dioica.
This is a community of ground kept permanent-ly moist by irrigation with base-rich, calcareous andgenerally oligotrophic waters. It is dependent onsustained irrigation common in areas of higher rain-fall. Here it can be found marking out spring-heads,seepage lines and drip zones in areas of lime-richbedrocks, where waters emerge along beddingplanes or at junctions with impervious substrates.Provided the ground is permanently wet, the com-munity can even occur on vertical surfaces and barerock, forming curtain-like masses. The communitycan be found throughout the north-western uplandsof Britain with its more Arctic-Alpine element bestdeveloped in the Scottish Highlands, with outliersin the Lake District and Upper Teesdale. Springsdominated by Cratoneuron species also occurwidely, but locally, in the British lowlands, and fur-ther sampling of these is needed.
In most circumstances it is a permanent community maintained by edaphic and climaticconditions of the environment. On gentle slopes,trampling by grazing stock or deer often plays animportant part in maintaining the characteristicallyopen conditions of flushed soils, but tramplingand grazing can have an adverse effect on thebryophyte carpet.
No sub-communities.
M37 Cratoneuron commutatum –Festuca rubra spring
69
This type of spring preserves the same pattern ofdominance by Cratoneuron commutatum (againoccasionally supplemented or replaced by C. filicinum) as in Cratoneuron commutatum –Festuca rubra spring (M37), but the associatedflora is much richer. This is partly seen among the bryophytes. Bryum pseudotriquetrum andPhilonotis fontana are the commonest and canhave moderately high cover, and there are manyothers which can occur locally as prominentpatches. These include calcicolous species such asAneura pinguis, Fissidens adianthoides, Philo-notis calcarea, Ctenidium molluscum, Cinclidiumstygium, Drepanocladus revolvens and Campy-lium stellatum.
The increased richness is most seen among thevascular plants. Small sedges are noticeable.Carex demissa, C. nigra and C. panicea areconstant and often abundant, and C. pulicaris,C. flacca and C. dioica are common. There are frequent scattered plants of Cardamine pratensis,Selaginella selaginoides, Leontodon autumnalis,Polygonum viviparum, Trifolium repens, Cirsiumpalustre, Ranunculus flammula, Sagina nodosa,
Juncus triglumis, J. articulatus, J. bulbosus,Cera-stium fontanum, Prunella vulgaris, Caltha palustris, Galium palustre, Equisetum palustre,Achillea ptarmica, Cochlearia officinalis (oftenssp. alpina), Triglochin palustris, Ranunculusacris, Anthoxanthum odoratum, Festuca ovina,Epilobium anagallidifolium and, in north England,the introduced E. nerteroides. In Teesdale thiscommunity is the locus for Saxifraga hirculus.
This vegetation is confined to montane springsand flushes strongly irrigated by base-rich, calcareous and oligotrophic waters. As in M37,sites of sustained irrigation with waters drainingfrom lime-rich bedrock are marked out and tufaencrustation is often seen. It is very local aroundUpper Teesdale in the north Pennines and in thecentral Highlands of Scotland, mostly above650 m altitude.
Although the harsh climatic and edaphic conditions exert a strong influence on the structure and composition of the vegetation, heavygrazing plays a major role in maintaining the distinctive richness of the community, and it isthis trampling and cropping by sheep and deerwhich is responsible for the most obvious floristicdifferences between this community and M37.
No sub-communities.
M38 Cratoneuron commutatum –Carex nigra spring
70
4 Dendrogram keys to heath communities
See
Fig
2.
1. C
allu
na
vulg
aris
may
be
pre
sen
t bu
t is
not
con
stan
t or
pro
min
ent
inth
e ve
geta
tion
.
A K
EY
TO
HE
AT
HS
1a. C
allu
na
vulg
aris
con
stan
t an
d u
sual
lyd
omin
ant
in t
he
vege
tati
on.
2. U
lex
spp
. con
stan
t in
the
swar
d a
nd
usu
ally
pro
min
ent.
See
Fig
1.
2a. U
lex
spp
. abs
ent
or,
if p
rese
nt,
th
en n
ot c
on-
stan
t an
d s
ubo
rdin
ate
inth
e ve
geta
tion
.
3. S
phag
num
cap
illif
oliu
m
con
stan
t w
ith
in a
lu
xuri
-an
t m
oss-
carp
et, u
sual
lyov
er s
teep
slo
pes
wit
h a
thin
min
eral
soi
l.
3a. S
phag
num
cap
illifo
lium
abse
nt
or, i
f p
rese
nt,
spar
se a
nd
in
freq
uen
t.
4. A
t le
ast
two
ofR
acom
itri
um
lan
ugi
-n
osu
m,C
lad
onia
ar
busc
ula
,C. u
nci
alis
,H
up
erzi
a se
lago
,E
mp
etru
m n
igru
m
her
map
hro
dit
um
an
dC
etra
ria
isla
nd
ica
con
stan
t in
th
e ve
geta
-ti
on. S
ub-
mon
tan
e an
dm
onta
ne
hea
ths.
5. R
acom
itri
um
lan
ugi
-n
osu
m a
nd
th
e ab
ove
spec
ies
not
con
stan
t.
At
leas
t on
e of
: Eri
caci
ner
ea,G
aliu
m s
axat
ile,
Vac
cin
ium
myr
till
us,
Fes
tuca
ovi
na,
Des
cham
psi
a fl
exu
osa
and
/or
Hyp
nu
m s
pp
.co
nst
ant
in t
he
vege
ta-
tion
. Low
lan
d a
nd
su
b-m
onta
ne
hea
ths.
See
Fig
4.
See
Fig
5.
See
Fig
3.
71
Heaths Figure 1
1. E
rica
vag
ans
pre
sen
tan
d u
sual
ly c
o-d
omin
ant
wit
h o
ther
sp
ecie
s.
Fig
1. K
ey t
o h
eath
s in
wh
ich
Ca
llu
na
vu
lga
ris
is n
ot c
onst
ant
or p
rom
inen
t bu
t m
ay b
e p
rese
nt
at l
ow f
requ
ency
.
3a. C
arex
big
elow
iiab
sen
t or
in
freq
uen
t,oc
casi
onal
ly l
ocal
lyab
un
dan
t. V
eget
atio
nu
sual
ly d
omin
ated
by
Vac
cin
ium
myr
till
us
wit
h c
onst
ant
Gal
ium
saxa
tile
,Des
cham
psi
afl
exu
osa,
Dic
ran
um
scop
ariu
m a
nd
P
leu
rozi
um
sch
rebe
ri.
2. E
rica
vag
ans
co-
dom
inan
t w
ith
Sch
oen
us
nig
rica
ns,
Mol
inia
caer
ule
a,E
rica
cin
erea
and
E. t
etra
lix;
Ule
x ga
llii
an
d G
enis
ta a
ngl
ica
som
etim
es f
requ
ent.
Typ
ical
of
the
east
an
dce
ntr
al H
igh
lan
ds
betw
een
th
e u
pp
er l
imit
of e
rico
id d
omin
ance
and
su
mm
it m
oss-
hea
ths.
H19
Vac
cin
ium
myr
till
us
–C
lad
onia
arb
usc
ula
h
eath
4. C
lad
onia
arb
usc
ula
con
stan
t an
d a
bun
dan
t.
Rac
omit
riu
m l
anu
gi-
nos
um
gen
eral
ly s
ubo
r-d
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e. E
mp
etru
mn
igru
m h
erm
aph
rod
itu
m
and
bu
lky
ple
uro
carp
ous
mos
ses
may
be
freq
uen
tbu
t n
ever
abu
nd
ant.
3. C
arex
big
elow
ii
con
stan
t an
d f
requ
ent.
H20
Vac
cini
um m
yrti
llus
–R
acom
itri
um
la
nu
gin
osu
m h
eath
Typ
ical
of
the
nor
th-w
est
Sco
ttis
h H
igh
lan
ds
betw
een
th
e u
pp
er l
imit
of e
rico
id d
omin
ance
and
su
mm
it m
oss-
hea
ths
H18
Vac
cini
um m
yrti
llus
–D
esch
amp
sia
flex
uos
ah
eath
Th
ese
com
mu
nit
ies
are
alm
ost
enti
rely
res
tric
ted
to
the
Liz
ard
Pen
insu
la i
n C
orn
wal
l.
4a. C
lad
onia
arb
usc
ula
not
con
stan
t bu
t m
ay b
efr
equ
ent.
Em
pet
rum
nig
rum
her
map
hro
dit
um
an
d m
ats
of b
ulk
y p
leu
roca
rpou
s m
osse
s:
Ple
uro
ziu
m s
chre
beri
,R
hyt
idia
del
ph
us
lore
us
Rac
omit
riu
m
lan
ugi
nos
um
an
d
Hyl
ocom
ium
sp
len
den
s co
nst
ant
and
abu
nd
ant.
H5
Eri
ca v
agan
s –
Sch
oen
us
nig
rica
ns
hea
th
H6
Eri
ca v
agan
s –
Ule
xeu
rop
aeu
s h
eath
2a. E
rica
vag
ans
co-
dom
inan
t w
ith
Ule
xeu
rop
aeu
s. U
lex
gall
iian
d E
rica
cin
erea
con
stan
t an
d f
requ
ent
ofte
n w
ith
Car
ex f
lacc
a,P
oten
till
a er
ecta
an
d
Pol
ygal
a vu
lgar
is. E
rica
tetr
alix
nev
er p
rom
inen
t.
1a. E
rica
vag
ans
abse
nt.
V
acci
niu
m m
yrti
llu
san
d/o
r E
mp
etru
mn
igru
m (
eith
er s
ub-
spec
ies)
con
stan
t an
dp
rom
inen
t. M
onta
ne
hea
ths
in n
orth
ern
Bri
tain
.
72
Heaths Figure 2
1. Ulex minor con-stant and usuallyprominent.
Fig 2. Key to heaths with constant Calluna vulgaris and in which Ulex spp. are constant and prominent
2. Agrostis curtisii,Molinia caerulea,Erica cinerea and E.tetralixconstant.
H3 Ulex minor –Agrostis curtisii heath
Restricted in its occurrence to Dorset andHampshire.
2a. Agrostis curtisiiabsent or present onlyat low frequency.Erica tetralix neverfrequent.
H2 Calluna vulgaris –Ulex minor heath
1a. Ulex minor gener-ally absent. Ulex galliiconstant and promi-nent.
3. Agrostis curtisii, Molinia caerulea,Erica cinerea and E.tetralixconstant.
H4 Ulex gallii –Agrostis curtisii heath
Found mainly insouth-west Britain.
3a. Agrostis curtisiigenerally absent;Erica tetralix neverfrequent.Ulex europaeus maybe abundant.
H8 Calluna vulgaris –Ulex gallii heath
Heaths Figure 3
73
1. Vaccinium vitis-idaea and Cladoniaarbuscula constantin the vegetation.Rubus chamaemorusfrequent and may beprominent.
Fig 3. Key to heaths with constant Calluna vulgaris and Sphagnum capillifolium over a luxuriant bryophyte-rich carpet.Constants include: Vaccinium myrtillus, Empetrum nigrum nigrum, Deschampsia flexuosa, Rhytidiadelphus loreus,Pleurozium schreberi, Dicranum scoparium and Hylocomium splendens.
H22 Vaccinium myrtillus-Rubuschamaemorus heath
Almost entirely confined in its distribution to the central and north-west Highlands.
H21 Calluna vulgaris– Vaccinium myr-tillus – Sphagnumcapillifolium heath
Usually located onsteep, north-east tonorth-west facingslopes on thin miner-al soils, often withrock outcrops.
1a. Vaccinium vitis-idaea andCladonia arbusculaabsent or at very lowfrequency. ConstantPotentilla erecta. Thebryophyte carpetincludes Dicranummajus andPlagiotheciumundulatum.
74
1. J
un
iper
us
com
mu
nis
ss
p. n
ana
orA
rcto
stap
hyl
os a
lpin
us
con
stan
t, u
sual
ly w
ith
som
e E
rica
cin
erea
.
Fig
4. K
ey t
o su
b-m
onta
ne
and
mon
tan
e h
eath
s w
ith
con
stan
tC
all
un
a v
ulg
ari
san
d a
t le
ast
two
con
stan
ts f
rom
:Ra
com
itri
um
lan
ugi
nos
um
,Cla
don
ia a
rbu
scu
la,C
. un
cia
lis,
Hu
per
zia
sel
ago
,Em
pet
rum
nig
rum
her
ma
ph
rod
itu
man
dC
etra
ria
isl
an
dic
a.
3a R
acom
itri
um
la
nu
gin
osu
m c
an b
e fr
equ
ent
but
is r
arel
yab
un
dan
t. C
lad
onia
sp
p. u
sual
ly p
rom
inen
tin
clu
din
g co
nst
ant
C. a
rbu
scu
la,C
. un
cial
isan
d C
. ran
gife
rin
a.E
mp
etru
m n
igru
m
her
map
hro
dit
um
als
oco
nst
ant.
Des
cham
psi
afl
exu
osa
and
Hyp
nu
m
cup
ress
ifor
me
occa
sion
alan
d s
par
se.
2. V
eget
atio
n d
omin
ated
by J
un
iper
us
com
mu
nis
ssp
. nan
a w
ith
con
stan
t S
cirp
us
cesp
itos
us,
Des
cham
psi
a fl
exu
osa,
Pot
enti
lla
erec
ta,E
rica
cin
erea
,Rac
omit
riu
mla
nu
gin
osu
m,C
lad
onia
un
cial
is,P
leu
rozi
a p
urp
ure
a.
H14
Cal
lun
a vu
lgar
is –
Rac
omit
riu
m l
anu
gi-
nos
um
hea
th
4. R
acom
itri
um
la
nu
gin
osu
m f
orm
s a
den
se w
ooll
y m
at
5-10
cm
th
ick.
Cla
don
iaar
busc
ula
con
stan
t, E
rica
cin
erea
may
be
freq
uen
tbu
t n
ot c
onst
ant.
3. R
acom
itri
um
la
nu
gin
osu
m d
omin
ant,
usu
ally
wit
h c
onst
ant
Cla
don
ia u
nci
alis
.E
mp
etru
m n
igru
m
(eit
her
su
b-sp
ecie
s),
Des
cham
psi
a fl
exu
osa
and
Hyp
nu
m c
up
ress
i-fo
rme
can
be
freq
uen
t.
H10
b C
allu
na
vulg
aris
–E
rica
cin
erea
hea
th,
Rac
omit
riu
m l
anu
gi-
nos
um
su
b-co
mm
un
ity
H13
Cal
lun
a vu
lgar
is –
Cla
don
ia a
rbu
scu
lah
eath
4a. R
acom
itri
um
la
nu
gin
osu
m a
bun
dan
tbu
t n
ot f
orm
ing
a d
ense
mat
. Cla
don
ia a
rbu
scu
la
abse
nt.
Eri
ca c
iner
ea
con
stan
t.
H15
Cal
lun
a vu
lgar
is –
Jun
iper
us
com
mu
nis
ss
p. n
ana
hea
th
H17
Cal
lun
a vu
lgar
is –
Arc
tost
aph
ylos
alp
inu
sh
eath
2a.
Jun
iper
us
com
mu
nis
ssp
nan
a u
sual
ly a
bsen
t.
Arc
tost
aph
ylos
alp
inu
s co
nst
ant
in a
low
op
enm
at. A
lso
con
stan
t:
Hu
per
zia
sela
go,
Des
cham
psi
a fl
exu
osa,
Rac
omit
riu
m l
anu
gi-
nos
um
,Cla
don
ia a
rbu
s-cu
la a
nd
C. u
nci
alis
.
Heaths Figure 4
1a. J
un
iper
us
com
mu
nis
and
Arc
tost
aph
ylos
alp
i-n
us
abse
nt
or a
t ve
ry l
ow
freq
uen
cy. R
acom
itri
um
lan
ugi
nos
um
an
d/o
rC
lad
onia
sp
p.
pro
min
ent.
75
H11
Cal
lun
a vu
lgar
is –
Car
ex a
ren
aria
hea
th
1. S
cill
a ve
rna
and
Pla
nta
go m
arit
ima
con
stan
t in
sh
ort
hea
ths
arou
nd
mar
itim
e cl
iffs
.
Fig
5. K
ey t
o lo
wla
nd
an
d s
ub-
mon
tan
e h
eath
s w
ith
con
stan
t, u
sual
ly d
omin
ant
Ca
llu
na
vu
lga
ris
and
at
leas
t on
e of
Eri
ca c
iner
ea,V
acc
iniu
m m
yrti
llu
s,E
mp
etru
m n
igru
m n
igru
m,F
estu
ca o
vin
a,D
esch
am
psi
a f
lexu
osa
,Ga
liu
m s
axa
tile
and
Hyp
nu
m c
up
ress
ifor
me
con
stan
t in
th
e ve
geta
tion
.
1a. S
cill
a ve
rna
and
Pla
nta
go m
arit
ima
abse
nt.
2. C
arex
are
nar
ia
con
stan
t bu
t n
ot o
ften
pro
min
ent.
Am
mop
hil
aar
enar
ia f
requ
ent
but
spar
se. S
and
y d
un
esan
d c
oast
al p
lain
s.
H7
Cal
lun
a vu
lgar
is –
Sci
lla
vern
a h
eath
2a. C
arex
are
nar
ia a
nd
Am
mop
hil
a ar
enar
ia
abse
nt.
3. A
rcto
stap
hyl
os u
va-
urs
i an
d t
he
foll
owin
gsp
ecie
s co
nst
ant:
Eri
caci
ner
ea,V
. vit
is-i
dae
a,D
esch
amp
sia
flex
uos
a,C
lad
onia
im
pex
a an
d
ple
uro
carp
ous
mos
ses.
3a. A
rcto
stap
hyl
os
uva
-urs
i ab
sen
t or
rar
e.
4. E
rica
cin
erea
con
stan
tan
d u
sual
ly p
rom
inen
t.
H10
Cal
lun
a vu
lgar
is –
Eri
ca c
iner
ea h
eath
H12
Cal
lun
a vu
lgar
is –
Vac
cin
ium
myr
till
us
hea
th
H16
Cal
lun
a vu
lgar
is –
Arc
tost
aph
ylos
uva
-urs
ih
eath
4a. E
rica
cin
erea
not
co
nst
ant
and
pre
sen
ton
ly a
t lo
w f
requ
ency
.
5. D
esch
amp
sia
flex
uos
a co
nst
ant.
Vac
cin
ium
m
yrti
llu
s u
sual
ly
freq
uen
t.
6. V
acci
niu
m m
yrti
llu
s co
nst
ant.
Con
stan
t an
dfr
equ
ent
Dic
ran
um
sc
opar
ium
,Ple
uro
ziu
msc
hre
beri
,Hyp
nu
mcu
pre
ssif
orm
e an
d/o
r H
yloc
omiu
m s
ple
nd
ens.
H9
Cal
lun
a vu
lgar
is–
Des
cham
psi
afl
ex-
uos
a h
eath
6a. C
allu
na
vulg
aris
alw
ays
dom
inan
t bu
t V
acci
niu
m m
yrti
llu
s,V.
vit
is i
dae
a or
Em
pet
rum
nig
rum
nigr
um m
ay b
e lo
call
yab
un
dan
t. P
ohli
an
uta
ns
is c
onst
ant
but
oth
er
ple
uro
carp
ous
mos
ses
are
only
occ
asio
nal
.
H1
Cal
lun
a vu
l-ga
ris
–F
estu
caov
ina
hea
th
5a. D
esch
amp
sia
flex
uos
a ab
sen
t or
p
rese
nt
only
at
low
fre
quen
cy.
Cal
lun
a vu
lgar
isu
sual
ly t
he
only
abu
nd
ant
sub-
shru
b in
asp
ecie
s-p
oor
hea
th. O
ther
con
-st
ants
in
clu
de
Fes
tuca
ovi
na,
Hyp
nu
m
cup
ress
ifor
me
and
Dic
ran
um
sco
par
-iu
m.
Heaths Figure 5
76
5 Heath community descriptions and sub-community keys
This is a heather-dominated community which isvery poor in vascular associates, although some-times showing a modest diversity among thebryophytes and, more especially, the lichens.Calluna vulgaris is usually the only woody speciesand the most abundant. The height and cover ofthe canopy are very variable depending on the ageof the heather and the consequent phase of development, and also on grazing intensity. Ericacinerea, Ulex minor and U. gallii, important in dryheaths further south and west, are largely exclud-ed as is Erica tetralix. Ulex europaeus is uncom-mon, except where there has been disturbance.
Typically there are no grassy areas but Festucaovina is very common throughout, usually as scattered tussocks, often with less than 30% totalcover. Other grasses are few. Agrostis capillaris isoccasional and there may be a little Deschampsiaflexuosa. Associated dicotyledons are also fewand patchy. Occasionally Senecio jacobaea,Galium saxatile, Cerastium fontanum, Camp-anula rotundifolia and Luzula campestris may bepresent. Two species locally important in particu-lar situations are Pteridium aquilinum and Carexarenaria. In bare areas Rumex acetosella togetherwith ephemerals such as Aphanes arvensis,Teesdalia nudicaulis, Myosotis ramosissima andthe annual Aira praecox may be found.
Only a few bryophyte species occur throughoutthe community. Hypnum cupressiforme andDicranum scoparium are both constant. These twousually form the bulk of the bryophyte cover in
both pioneer and degenerate Calluna. In such sit-uations Hylocomium splendens, Pleuroziumschreberi, Ptilidium ciliare and Dicranella heteromalla are occasional. Lichens may exceedmosses in cover. Cladonia species are prominentwith encrusting species such as Cladonia pyxida-ta, C. squamosa and C. fimbriata on bare ground.Species like C. impexa, C. furcata and C. arbuscu-la are especially abundant on old Calluna togeth-er with Hypogymnia physodes.
This community is confined to acid, base-poorand oligotrophic sandy soils in the more continental lowlands of eastern England. The profiles under the community are usually brownsands which are free to excessive-draining andhave a low surface pH. In some localities, such asin Lincolnshire and around the Weald, the impoverished soils are derived from arenaceousbedrock, but they have mostly developed fromsandy glacio-fluvial drift, sometimes supplement-ed by aeolian sand. The community occursthrough the eastern lowlands of England, althoughit is now very local.
This heath has been traditionally managedwith burning and grazing (both domestic livestockand wild herbivores such as rabbits and deer).However in many areas the abandonment of thistraditional management has been followed by agricultural improvement or afforestation whichhas reduced and fragmented tracts of this community. In other areas the lack of grazing andburning has often permitted seral progression toscrub and woodland. The most common woodyinvaders are Betula pendula and Pinus spp., andmore occasionally, Quercus robur if mature treesare fairly close by.
H1 Calluna vulgaris – Festucaovina heath
77
Lic
hen
s p
oorl
y re
pre
sen
ted
.C
over
of
Cal
lun
a vu
lgar
is r
ath
er
open
wit
h s
ome
of C
lad
onia
un
cial
is,
C. f
imbr
iata
,C. p
yxid
ata,
C. i
mp
exa,
C. s
quam
osa,
Cor
nic
ula
ria
acu
leat
aan
d H
ypog
ymn
ia p
hys
odes
loc
ally
abu
nd
ant
on m
or a
nd
bar
e gr
oun
d.
H1a
Hyp
nu
m c
up
ress
ifor
me
sub-
com
mu
nit
y
Cov
er o
f C
allu
na
vulg
aris
is o
ften
les
s th
an c
omp
lete
an
don
ly m
oder
atel
y ta
ll.
Th
e m
ost
pro
min
ent
asso
ciat
es a
re
Fes
tuca
ovi
na
and
th
e cr
yp-
toga
ms
wh
ich
oft
en e
xcee
d
50%
cov
er. A
mon
g th
e m
osse
s H
ypn
um
cu
pre
ssif
orm
e an
d
Dic
ran
um
sco
par
ium
are
ver
yfr
equ
ent.
Lic
hen
s ar
e al
so
abu
nd
ant,
Cla
don
ia p
yxid
ata,
C. s
quam
osa,
C. f
imbr
iata
an
d
C. g
raci
lis
usu
ally
pre
dom
inat
e,bu
lkie
r sp
ecie
s li
ke C
. im
pex
a,C
. un
cial
is a
nd
C. a
rbu
scu
labe
ing
less
fre
quen
t an
d
Hyp
ogym
nia
ph
ysod
esoc
casi
onal
.
Hyp
nu
m c
up
ress
ifor
me
very
com
mon
am
ong
coll
apse
d
Cal
lun
a vu
lgar
is a
nd
in
gr
assy
pat
ches
.
H1b
Hyp
ogym
nia
ph
ysod
es–
Cla
don
ia i
mp
exa
sub-
com
mu
nit
y
Th
e h
eath
er c
over
is
the
sam
eas
in
H1a
bu
t d
egen
erat
e bu
shes
pre
dom
inat
e. T
he
con
trib
uti
onof
Fes
tuca
ovi
na,
Hyp
nu
mcu
pre
ssif
orm
e an
d D
icra
nu
msc
opar
ium
is m
ore
un
even
, th
e m
osse
s oc
curr
ing
as s
mal
lp
atch
es a
mon
g co
llap
sed
ste
ms.
Lic
hen
s by
con
tras
t ar
e ab
un
-d
ant
in t
hes
e ar
eas,
en
cru
stin
gsp
ecie
s be
ing
join
ed o
r ex
ceed
-ed
by
Cla
don
ia i
mp
exa,
C. f
urc
ata
and
C. m
acil
enta
.H
ypog
ymn
ia p
hys
odes
is
mos
tfr
equ
ent
her
e.
Bry
oph
ytes
rat
her
pat
chy
but
lich
ens
ofte
n e
xten
sive
wit
h
Cla
don
ia f
urc
ata
and
C
. mac
ilen
ta c
omm
on.
H1e
Sp
ecie
s-p
oor
sub-
com
mu
nit
y
Un
brok
en c
anop
ies
of d
ense
and
oft
en t
all
hea
ther
, up
to
50
cm o
r m
ore
hig
h, a
re
char
acte
rist
ic h
ere,
am
ong
wh
ich
vir
tual
ly n
o as
soci
ates
can
su
rviv
e, a
par
t fr
om
occa
sion
al s
par
se p
lan
ts
of H
ypn
um
cu
pre
ssif
orm
e.
Th
is s
ub-
com
mu
nit
y is
ty
pic
ally
of
buil
din
g an
dm
atu
re h
eath
er.
H1d
Ca
rex
are
na
ria
su
b-co
mm
un
ity
Th
e h
eath
er i
s of
ten
tal
l an
dso
mew
hat
op
en w
ith
sca
tter
edp
lan
ts o
r d
ense
r p
atch
es o
f C
arex
are
nar
ia, s
omet
imes
co
-dom
inan
t an
d g
row
ing
onsa
nd
y so
il p
rofi
les.
Fes
tuca
ovin
a oc
curs
sp
arse
ly
som
etim
es w
ith
a l
ittl
e R
um
ex a
ceto
sell
a,bu
t ot
her
her
bs a
re s
carc
e. A
mon
g th
ecr
ypto
gam
s on
ly H
ypn
um
cup
ress
ifor
me
is f
requ
ent.
Th
is s
ub-
com
mu
nit
y is
fou
nd
on c
oast
al a
nd
in
lan
d d
un
e sy
stem
s.
Teu
criu
m s
coro
don
ia f
requ
ent
wit
h S
enec
io ja
coba
ea,A
gros
tis
cap
illa
ris
and
Gal
ium
sax
atil
e oc
casi
onal
.
Car
ex a
ren
aria
con
stan
t,
som
etim
es a
bun
dan
t.V
ery
imp
over
ish
ed r
ank
can
opie
s of
Cal
lun
a vu
lgar
is.
H1c
Teu
criu
m s
coro
don
iasu
b-co
mm
un
ity
Deg
ener
ate
bush
es a
re s
carc
ean
d h
eath
er c
over
is
gen
eral
lyvi
goro
us
and
ext
ensi
ve.
Wit
hin
mor
e op
en a
reas
sc
atte
red
pla
nts
of
Teu
criu
msc
orod
onia
or
Sen
ecio
jaco
baea
can
be
fou
nd
or
smal
l st
retc
hes
of t
urf
wit
h F
estu
ca o
vin
a,A
gros
tis
cap
illa
ris,
Des
cham
psi
afl
exu
osa
and
sca
tter
ed R
um
exac
etos
ella
,Gal
ium
sax
atil
e an
dC
eras
tiu
m f
onta
nu
m. L
ich
ens
are
very
in
freq
uen
t, b
ut
Hyp
nu
m c
up
ress
ifor
me
and
Dic
ran
um
sco
par
ium
rem
ain
com
mon
.
H1
78
This community is generally dominated byCalluna vulgaris, but with both Erica cinerea andUlex minor playing a very frequent and sometimesprominent role in the sub-shrub layer. The constancy of the latter two species provides themost obvious floristic distinction between thiscommunity and the Calluna vulgaris – Festucaovina heath (H1). The canopy is very variable inheight, from 10 cm to 80 cm or more, and thestructure depends greatly on the growth phase ofthe Calluna and whether the individuals are ofeven or uneven age. Where burning occurs (forexample, in the New Forest) a characteristic patchwork of swales is formed. After fire E. cin-erea often increases in frequency because of itsprolific seeding. Ulex minor normally plays a sub-sidiary role, forming a patchy understorey belowthe Calluna. No other sub-shrubs are foundthroughout the community. Ulex europaeus isoccasional, but may be locally abundant after disturbance. Erica tetralix and Vaccinium myr-tillus are found in particular sub-communities.
Other consistent associates are very few.Deschampsia flexuosa is constant but patchy,though it may be more common in grazed areas.On wetter soils it tends to be replaced by Moliniacaerulea. Pteridium aquilinum is occasional overall and preferential for one sub-community.Scattered plants of Potentilla erecta or Galium
saxatile may also be found in more open areas. Insome stands invading seedling and sapling treesmay occur, particularly Quercus spp., Betula spp.and Pinus sylvestris.
In the absence of burning, mosses and lichenscan become common. Dicranum scoparium andHypnum jutlandicum are the most frequentbryophytes, with peat-encrusting Cladonia speciesand larger species such as Cladonia furcata and C. arbuscula. Hypogymnia physodes can some-times be found on old heather stems.
This community is characteristic of impoverishedacid soils, predominantly free-draining in south-eastand central southern England. It is characteristic offree-draining profiles developed from pervious arena-ceous or pebbly parent materials. Typically, these par-ent materials have given rise to some kind of podzolicprofile under this community which is highly acidic,often with a superficial pH between 3.5 and 4.5, andgenerally impoverished. The community occurs fromthe Poole Harbour area in the west through the NewForest, where stands are particularly numerous andextensive, to Surrey and the High Weald in the east,where it occurs as more local and fragmented tracts ofheathland.
The vegetation takes much of its structural, andsome of its floristic, character from traditionalgrazing and burning treatments. However, whenreleased from these treatments a progression towoodland can be expected. Agricultural improve-ments and forestry have caused fragmentation andisolation of small remnants of this community inmany places.
H2 Calluna vulgaris –Ulex minor heath
79
Pte
rid
ium
aqu
ilin
um
can
be
quit
e co
mm
on, b
ut
Vac
cin
ium
myr
till
us
and
you
ng
tree
s ve
rysc
arce
.
H2
Vac
cin
ium
myr
till
us
con
stan
tan
d l
ocal
ly a
bun
dan
t, P
teri
diu
maq
uil
inu
m f
requ
ent
and
wit
hsc
atte
red
tre
e se
edli
ngs
an
dsa
pli
ngs
.
H2b
Va
ccin
ium
myr
till
us
sub-
com
mu
nit
y
Th
e su
b-sh
rub
can
opy
usu
ally
con
sist
s of
mix
ture
s of
hea
ther
wit
h s
omet
imes
su
bsta
nti
alam
oun
ts o
f U
lex
min
or,E
rica
cin
erea
an
d, s
tron
gly
pre
fere
n-
tial
, Vac
cin
ium
myr
till
us.
Pte
rid
ium
aqu
ilin
um
is
mor
efr
equ
ent,
an
d i
n o
pen
are
asth
ere
is u
sual
ly s
ome
Des
cham
psi
a fl
exu
osa
and
occa
sion
ally
a l
ittl
e M
olin
iaca
eru
lea.
You
ng
tree
s ar
e al
sost
ron
gly
pre
fere
nti
al, w
ith
oak
and
bir
ch s
eed
lin
gs a
nd
sap
lin
gs f
requ
ent,
an
d s
mal
lp
ines
loc
ally
pro
min
ent.
Hyp
nu
m ju
tlan
dic
um
an
dD
icra
nu
m s
cop
ariu
m a
re o
cca-
sion
al b
ut
lich
ens
are
spar
se.
Th
is s
ub-
com
mu
nit
y te
nd
s to
be
fou
nd
at
the
hig
her
alt
itu
des
in
the
ran
ge o
f H
2.
H2a
Typ
ical
su
b-co
mm
un
ity
Cal
lun
a vu
lgar
is i
s ge
ner
ally
stro
ngl
y d
omin
ant
wit
h s
ub-
sid
iary
am
oun
ts o
f U
lex
min
oran
d E
rica
cin
erea
, th
e la
tter
very
var
iabl
e an
d s
omet
imes
abse
nt.
Nei
ther
Vac
cin
ium
myr
-ti
llu
s n
or E
rica
tet
rali
x oc
cur
and
Mol
inia
cae
rule
a is
sca
rce.
Des
cham
psi
a fl
exu
osa
is c
om-
mon
an
d s
omet
imes
wit
h o
rre
pla
ced
by
Fes
tuca
ru
bra.
Pte
rid
ium
aqu
ilin
um
an
d t
ree
seed
lin
gs a
re i
nfr
equ
ent.
Bry
oph
ytes
an
d l
ich
ens
can
be
con
spic
uou
s am
ong
old
erh
eath
er o
r af
ter
burn
ing,
w
ith
Cla
don
ia f
imbr
iata
,C
. coc
cife
ra,C
. ch
loro
ph
aea
and
C. a
rbu
scu
la a
ll s
ligh
tly
pre
fere
nti
al.
Mol
inia
cae
rule
a ve
ry c
omm
on,
ofte
n a
lmos
t to
tall
y d
isp
laci
ng
Des
cham
psi
a fl
exu
osa.
Eri
cate
tral
ix f
requ
ent
and
som
etim
esex
ceed
ing
E. c
iner
ea.
Mol
inia
cae
rule
a oc
casi
onal
at
mos
t w
ith
Des
cham
psi
a fl
exu
osa
very
com
mon
. Dic
ran
um
sco
-p
ariu
m a
nd
Hyp
nu
m e
rice
to-
rum
wit
h C
lad
onia
sp
p.p
atch
i-ly
pro
min
ent
in m
ore
open
area
s.
H2c
Mol
inia
ca
eru
lea
sub-
com
mu
nit
y
Cal
lun
a vu
lgar
is i
s ab
un
dan
t,u
sual
ly w
ith
sm
alle
r am
oun
ts
of U
lex
min
or a
nd
par
ticu
larl
yof
Eri
ca c
iner
ea w
hic
h m
ay b
ejo
ined
wit
h o
r re
pla
ced
by
Eri
ca t
etra
lix.
Mor
e ob
viou
sly
pre
fere
nti
al i
s M
olin
ia c
aeru
lea.
Pte
rid
ium
aqu
ilin
um
is
un
com
-m
on a
nd
you
ng
tree
s ar
e ra
rely
fou
nd
. T
he
grou
nd
lay
er i
s al
so s
par
se.
Th
is s
ub
com
mu
nit
y is
p
red
omin
antl
y fo
un
d o
n s
oils
wit
h i
mp
eded
dra
inag
e.
80
This community contains nearly all the sub-shrubvegetation in which Ulex minor and Agrostis curtisii occur together as important components,although A. curtisii can also occur occasionally inCalluna vulgaris – Ulex minor heath (H2). Thecanopy is usually fairly low, 20-30 cm high, andCalluna frequently dominates, especially when ithas not been burned for some time. Compared withless oceanic heaths the most unusual feature of thewoody cover is the occurrence together of Ericacinerea and E. tetralix, both of which are constants.Both can grow vigorously, although E. cinerea islikely to be more prominent especially after burn-ing. Erica tetralix can have high cover locally, espe-cially on more strongly gleyed soils. Ulex minormaintains its high frequency throughout, althoughits abundance is very variable. In stands whichhave not been burnt for some time A. curtisii andMolinia caerulea, the two characteristic and con-stant grasses, are generally scattered, but afterburning A. curtisii and to a lesser degree Moliniacan become prominent. In contrast to H2Deschampsia flexuosa is very scarce. Pteridiumaquilinum occurs occasionally and other herbs arefound as scattered individuals. Potentilla erecta,Polygala serpyllifolia, Carex pilulifera and the par-asitic Cuscuta epithymum can all be found occa-sionally. In disturbed or burned situations Violalactea is very characteristic.
Burning has the effect of opening the canopy, andmosses and lichens become prominent. Among the
bryophytes Campylopus brevipilus is most distinc-tive and can be accompanied by C. paradoxus,Polytrichum juniperinum, Dicranum scoparium,Hypnum jutlandicum and Leucobryum glaucum.Cladonia impexa is one of the most common andconspicuous lichens with peat-encrusting speciessuch as C. floerkeana, C. coccifera and C. pyxidata.Hypogymnia physodes often colonises old heatherstems.
This community is the characteristic sub-shrubcommunity of impoverished acid soils which areprotected against parching by a measure ofdrainage impedance and a moderately oceanic climate. It occupies a distinct position on soilsthat are too dry for the Erica tetralix – Sphagnumcompactum wet heath (M16) and too moist for theCalluna vulgaris – Ulex minor heath (H2). It islargely confined to south Dorset and Hampshire.
The combination of drainage impedance and climate is the major influence on the floristicsof this community, although grazing and burn-ing still often exert an important measure ofcontrol on its composition and structure. Thegeneral effect of the combination of these treat-ments is to curtail the mature and degeneratephase of Calluna and to set back repeatedly anyinvasion of trees and seral progression to wood-land. The abandonment of traditional land useand soil improvement for agriculture in manystands of this type of vegetation has meant thatsurviving tracts can be fragmented, and areoften sharply delineated from their surrounds.
H3 Ulex minor – Agrostis curtisii heath
81
Agr
osti
s cu
rtis
ii v
ery
freq
uen
t,bu
t n
ot e
xten
sive
, an
d U
lex
euro
pae
us
occa
sion
al a
t m
ost
amon
g m
ixed
or
Cal
lun
a vu
l-ga
ris-
dom
inat
ed c
anop
ies.
H3
Cal
lun
a vu
lgar
is a
nd
Eri
cate
tral
ix r
edu
ced
in
fre
quen
cyan
d c
over
an
d M
olin
ia c
aeru
lea
and
Ule
x m
inor
som
ewh
atp
atch
y. A
gros
tis
curt
isii
ver
yab
un
dan
t w
ith
Ule
x eu
rop
aeu
sco
mm
on a
nd
Vio
la l
acte
a of
ten
per
sist
ent.
H3c
Agr
osti
s cu
rtis
iisu
b-co
mm
un
ity
Agr
osti
s cu
rtis
ii i
s ve
ry a
bun
-d
ant
and
Eri
ca c
iner
ea o
ften
co-
dom
inan
t, b
ut
Ule
x m
inor
an
dM
olin
ia c
aeru
lea
are
pat
chy
and
Cal
lun
a vu
lgar
is a
nd
Eri
cate
tral
ix m
uch
red
uce
d i
n
freq
uen
cy a
nd
cov
er. U
lex
euro
pae
us
is s
tron
gly
pre
fere
n-
tial
in
th
is s
ub-
com
mu
nit
yw
her
e d
istu
rban
ce, o
ften
by
burn
ing,
is
char
acte
rist
ic. T
he
earl
y st
ages
of
dev
elop
men
tof
ten
all
ow c
olon
isat
ion
by
Vio
la l
acte
a,w
hic
h t
hen
per
-si
sts
as t
he
dom
inan
ts e
xpan
d.
H3a
Typ
ical
su
b-co
mm
un
ity
Th
e su
b-sh
rubs
typ
ical
ly f
orm
an e
xten
sive
can
opy,
oft
en w
ith
Cal
lun
a vu
lgar
is a
s th
e m
ain
dom
inan
t, a
lth
ough
, som
etim
esm
ore
mix
ed.
Gra
sses
are
usu
al-
ly s
ubo
rdin
ate.
U
lex
euro
pae
us
is o
ccas
ion
al a
nd
Eri
ca c
ilia
ris
is f
oun
d i
n s
outh
Dor
set
vege
ta-
tion
. O
ther
sp
ecie
s ar
e fe
w,
alth
ough
Pot
enti
lla
erec
tais
pre
fere
nti
al a
t lo
w f
requ
ency
,an
d t
her
e is
som
etim
es a
lit
tle
Pte
rid
ium
aqu
ilin
um
,Car
exp
ilu
life
ra,P
olyg
ala
serp
ylli
foli
aor
Cu
scu
ta e
pit
hym
um
.B
ryop
hyt
es a
nd
lic
hen
s ar
esp
arse
.
Pol
ygal
a se
rpyl
lifo
lia
com
mon
wit
h a
pat
chy
cove
r of
bry
o-p
hyt
es a
nd
lic
hen
s on
mor
eop
en a
reas
. S
pec
ies
pre
sen
tin
clu
de
Cam
pyl
opu
s br
evip
ilu
s,P
olyt
rich
um
jun
iper
inu
m,
Cla
don
ia i
mp
exa,
C. f
loer
k-ea
na
and
C. c
occi
fera
.
Sp
ecie
s op
pos
ite
very
sp
arse
amon
g u
sual
ly d
ense
su
b-sh
rub
can
opie
s.
H3b
Cla
don
iasp
p. s
ub-
com
mu
nit
y
Th
e su
b-sh
rub
can
opy
is
som
ewh
at o
pen
, an
d a
lth
ough
Cal
lun
a vu
lgar
is i
s th
e le
adin
gsp
ecie
s, d
omin
ance
is
ofte
nsh
ared
bet
wee
n w
ood
y p
lan
tsan
d P
olyg
ala
serp
ylli
foli
a, a
stro
ng
pre
fere
nti
al h
ere.
Th
ere
is a
not
icea
ble
cove
r of
mos
ses
and
lic
hen
s, t
he
spec
ies
list
edab
ove
bein
g m
ost
freq
uen
t.
82
This community is very similar to Ulex minor –Agrostis curtisii heath (H3), with the replacementof one gorse by another. The western limit of U. minor in east Dorset forms the boundary bet-ween these two heath types. Apart from this dif-ference they share five constants, namely, Callunavulgaris, Erica cinerea, E. tetralix, Molinia caer-ulea and Agrostis curtisii, and these species,together with U. gallii, generally account for thebulk of the vascular cover. Their proportions and structure, however, vary considerably so that theappearance of stands differs markedly. The vegeta-tion can vary from a short mixed canopy of grass-es and sub-shrubs no more than 10 cm high (grassheath), to a canopy of woody plants 50 cm or morehigh. There may also be quite extensive areas ofbarer ground. Calluna and U. gallii are the mostcommon species and are often abundant. Callunaoften dominates. The frequent occurrence of E. cinerea and E. tetralix together distinguishesthis vegetation from the corresponding dry heathCalluna vulgaris – Ulex gallii heath (H8). Fourother sub-shrubs are more restricted. Vacciniummyrtillus is commoner at higher altitudes withincreased rainfall. The others, Salix repens, Ericaciliaris and E. vagans (a species restricted to the Lizard in Cornwall) are found in the wetter E. tetralix sub-community.
Two grasses are constant, Agrostis curtisii andMolinia caerulea, which always make some contribution to the cover. Among the grassier
heaths, Festuca ovina and Danthonia decumbensare particularly important, with the sedges Carexbinervis and C. pilulifera also characteristic. Oncooler, moister slopes Scirpus cespitosus can beprominent. The only dicotyledonous herb whichis a constant of this community is Potentilla erec-ta, which occurs as scattered individuals. Otheroccasional herbs are Polygala serpyllifolia andPedicularis sylvatica, with Viola lactea in dis-turbed situations. There are a variety of bryo-phytes and lichens, but none occur with any frequency.
This community is confined to the warmoceanic parts of south-west Britain where it occurson a variety of moist, acid soils. Like its eastern counterpart, H3, this is a vegetation type of acidsoils that are too moist for dry heath but not soconsistently waterlogged as to be able to sustainwet heath. The community is confined to south-west Britain, beyond a line from mid-Dorset to theQuantocks, and including parts of the south Walesseaboard up to altitudes of 500 m.
Both climatic and edaphic conditions combineto influence the general character of this vegetation.However, in most situations burning and grazinghave a marked effect on the floristics and physiog-nomy of the vegetation and, with the exception ofsituations such as the Lizard where exposure tohigh and frequent winds is combined with a scarci-ty of seed parents, these treatments are importantfor maintaining the community against successionto woodland. As with many lowland heath com-munities intensive improvement for agricultureand afforestation has reduced and fragmented itsextent.
H4 Ulex gallii – Agrostis curtisii heath
83
Eri
ca t
etra
lix
a fr
equ
ent
com
pon
ent
of t
he
sub-
shru
bco
mm
un
ity.
H4
Eri
ca t
etra
lix
very
in
freq
uen
t in
veg
eta-
tion
usu
ally
dom
inat
ed b
y A
gros
tis
cur-
tisi
ior
E. c
iner
ea. H
4a
Agr
osti
s cu
rtis
ii–
Eri
ca c
iner
easu
b-co
mm
un
ity
Un
usu
ally
th
ere
is a
n a
lmos
t to
tal
abse
nce
of
Eri
ca t
etra
lix.
Oth
erw
ise
all
the
con
stan
ts r
emai
n f
requ
ent
exce
pt
for
Agr
osti
s cu
rtis
ii w
hic
h i
s of
ten
dom
-in
ant,
for
min
g a
virt
ual
ly p
ure
an
d t
us-
sock
y sw
ard
. O
ther
gra
sses
do
not
gen
-er
ally
in
crea
se i
n c
over
. O
ther
vas
cula
ran
d c
ryp
toga
m a
ssoc
iate
s ar
e fe
w i
nn
um
ber.
Th
is s
ub-
com
mu
nit
y oc
curs
th
rou
ghou
tth
e ra
nge
of
H4
and
is
ofte
n p
rese
nt
asre
gen
erat
ing
vege
tati
on a
fter
bu
rnin
g.
Sci
rpu
s ce
spit
osu
s ab
sen
t fr
omve
geta
tion
var
iou
sly
dom
inat
edby
on
e or
mor
e su
b-sh
rubs
an
dgr
asse
s an
d w
ith
Eri
ca v
agan
sor
E. c
ilia
ris
loca
lly
abu
nd
ant.
Eri
ca c
iner
ea r
ath
er p
atch
y bu
tV
acci
niu
m m
yrti
llu
s co
mm
on i
na
gras
sy h
eath
wit
h F
estu
caov
ina,
Dan
thon
ia d
ecu
mbe
ns,
Agr
osti
s ca
pil
lari
s,G
aliu
m s
ax-
atil
e an
d o
ccas
ion
al C
arex
pil
uli
fera
an
d C
. bin
ervi
s.
Eri
ca c
iner
ea a
nd
E. t
etra
lix
both
ver
y co
mm
on, b
ut
asso
ci-
ates
lis
ted
op
pos
ite
occa
sion
alat
mos
t in
a l
ess
gras
sy h
eath
.
H4b
Fes
tuca
ovi
na
sub-
com
mu
nit
y
Agr
osti
s cu
rtis
iiis
oft
en t
he
mos
t ab
un
dan
tsp
ecie
s, m
ost
com
mon
ly w
ith
a f
airl
y ri
chm
ixtu
re o
f su
b-sh
rubs
an
d h
erbs
for
min
g a
gras
s h
eath
. Bot
h U
lex
gall
ii a
nd
Cal
lun
avu
lgar
is h
ave
hig
h f
requ
enci
es; E
rica
cin
erea
is
mor
e p
atch
y an
d E
rica
tet
rali
x-co
mm
on b
ut
not
con
stan
t. V
acci
niu
m m
yr-
till
us
is m
ost
com
mon
in
th
is s
ub-
com
mu
-n
ity,
oft
en a
s sp
arse
sh
oots
. Th
e as
soci
ates
list
ed a
bove
are
mor
e ab
un
dan
t an
d p
refe
r-en
tial
. Pot
enti
lla
erec
ta i
s ve
ry c
omm
on,
ofte
n w
ith
Gal
ium
sax
atil
e.B
ryop
hyt
es a
nd
lich
ens
are
very
sp
arse
in
un
graz
ed s
tan
ds
but
occa
sion
al i
n g
raze
d v
eget
atio
n.
Th
is s
ub-
com
mu
nit
y, a
lon
g w
ith
th
eS
cirp
us
sub-
com
mu
nit
y, c
an b
e fo
un
d a
th
igh
er a
ltit
ud
es o
n D
artm
oor
and
Exm
oor
and
als
o th
rou
ghou
t th
e ra
nge
on
fr
ee-d
rain
ing
soil
s w
ith
gra
zin
g.
H4c
Eri
ca t
etra
lix
sub-
com
mu
nit
y
Bot
h g
rass
es a
nd
su
b-sh
rubs
hav
e ve
ry h
igh
fre
quen
cy,
incl
ud
ing
Eri
ca t
etra
lix,
an
d e
ach
can
be
abu
nd
ant.
Pot
enti
lla
erec
ta i
s fr
equ
ent
and
Dan
thon
ia d
ecu
mbe
ns,
Pol
ygal
a se
rpyl
lifo
lia
and
C
arex
pan
icea
occ
asio
nal
. Th
is
vege
tati
on i
s be
st k
now
n o
n t
he
Liz
ard
wh
ere
Eri
ca c
ilia
ris
or
E. v
agan
s oc
cur
in t
his
typ
e of
hea
th. B
ryop
hyt
es a
nd
lic
hen
ssh
ow a
var
yin
g re
pre
sen
tati
on.
Th
is s
ub-
com
mu
nit
y is
esp
e-ci
ally
ch
arac
teri
stic
of
low
eral
titu
des
an
d i
s w
ell
rep
rese
nt-
ed o
n t
he
Dev
on P
ebbl
e-B
edco
mm
ons,
th
e lo
wer
fri
nge
s of
Dar
tmoo
r an
d B
odm
in M
oor
and
on
th
e L
izar
d.
H4d
Sci
rpu
s ce
spit
osu
ssu
b-co
mm
un
ity
Sci
rpu
s ce
spit
osu
s is
con
stan
tan
d s
tron
gly
pre
fere
nti
al w
ith
very
fre
quen
t C
allu
na
vulg
aris
,M
olin
ia c
aeru
lea
and
Eri
cate
tral
ix a
nd
com
mon
E. c
iner
eaan
d V
acci
niu
m m
yrti
llu
s. U
lex
gall
ii a
nd
Agr
osti
s cu
rtis
ii,b
oth
con
stan
ts, d
isti
ngu
ish
th
is s
ub-
com
mu
nit
y fr
om w
et h
eath
.D
icra
nu
m s
cop
ariu
m a
nd
Leu
cobr
yum
gla
ucu
m a
re f
re-
quen
t an
d C
lad
onia
im
pex
a an
d C
. un
cial
is o
ccas
ion
al.
Th
is s
ub-
com
mu
nit
y, a
lon
gw
ith
th
e F
estu
ca s
ub-
com
mu
ni-
ty, c
an b
e fo
un
d a
t h
igh
er a
lti-
tud
es o
n D
artm
oor
and
Exm
oor.
Sci
rpu
s ce
spit
osu
s co
nst
ant
inve
geta
tion
usu
ally
dom
inat
edby
Cal
lun
a vu
lgar
is, b
ut
wit
hot
her
su
b-sh
rubs
an
d g
rass
eslo
call
y ab
un
dan
t.
84
This heath is one of two sub-shrub communitiesin which the nationally-rare Erica vagans makesa constant and prominent contribution. Schoe-nus nigricans is also constant and usually abun-dant as strongly-developed tussocks. Moliniacaerulea and Erica tetralix are also constant,often with high cover, and together these fourspecies dominate in mixtures. Between thesespecies there is a well-defined system of runnelsgiving a distinct microhabitat. Among other sub-shrubs only Ulex gallii occurs with any frequen-cy and may be co-dominant. Calluna is onlyoccasional and E. cinerea scarce. Genista anglica,however, can occur frequently and is preferentialto this community.
In undisturbed stands which have not beenburnt or grazed recently, Schoenus and E. vaganstend to be dominant and the vegetation is chokedwith their litter. Then, even common associateslike Potentilla erecta and Festuca ovina can be crowded out. After burning or grazing, or both, theassociated flora is much richer. In the wetter run-nels sedges are often important with Carex puli-caris constant, C. panicea and C. flacca frequentand, on gabbro, C. hostiana. Anagallis tenella, alsoconstant, may form extensive mats. Among tallerherbs Serratula tinctoria and Succisa pratensis areconstant and Sanguisorba officinalis frequent.
There are a number of occasional associates. Onwetter ground Phragmites australis can be presentas conspicuous but scattered shoots.
Bryophytes vary considerably among stands but Campylium stellatum is constant and very frequent in runnels and may be abundant,often with Riccardia multifida, R. sinuata and,over gabbro, Scorpidium scorpioides. After wetweather runnels often have swollen gelatinousglobules of blue-green algae.
This community is confined to wet, base-rich but calcium-poor mineral soils and shallow peats on the Lizard in Cornwall. Here the distinc-tive parent materials of serpentine and gabbrofound in this area have given rise to soils that havea superficial pH of between 5.5 and 7.5 but inwhich magnesium predominates over calcium.The community makes the major proportion of theopen and enclosed heaths of the hinterland of the peninsula.
The floristics of this community are influencedboth by the mild oceanic climate and underlyingbedrocks of serpentine and gabbro, but the com-position and physiognomy of particular stands areaffected by burning and sometimes also by graz-ing. Other past treatments like the cutting of turfhave also probably influenced the appearance and distribution of this community. There have been losses of this vegetation type to modern techniques of land improvement and much of theremaining extent has statutory or voluntary pro-tection.
H5 Erica vagans – Schoenusnigricans heath
85
Vegetation variable in composition and structure, but species listed opposite rare.
Frequent Eleocharis multicaulis,Eriophorum angustifolium, Droserarotundifolia, Pinguicula lusitanica, andDactylorhiza incarnata incarnata grow-ing in runnels that are usually floodedfor much of the year. In ungrazedstands, Phragmites australis maybe locally abundant.
H5b
Eleocharis multicaulis sub-community
Schoenus nigricans dominant withMolinia caerulea and Erica vagans.Erica tetralix is somewhat less abun-dant. Calluna vulgaris and Erica tetralix usually absent and Carex panicea is also typically missing.
H5a
Typical sub-community
This vegetation has all the general features of the community with noadditional preferential species. Thetussock/runnel structure is often well-defined, but species-richness dependsgreatly on treatment and especiallytime since burning.
H5
86
This community is a distinctive type of sub-shrubvegetation, but rather variable in floristics andstructure. The most obvious feature is a mixedcanopy of sub-shrubs in which Erica vagans andUlex europaeus are the usual co-dominants. Thecanopy is generally 30-60 cm high but in exposedsituations may be not more than 10 cm high. Two other constant sub-shrubs, Ulex gallii and E. cinerea, can also be abundant although the for-mer may be suppressed in dense stands. Calluna vulgaris is not frequent and has generally low cover.
In contrast to the Erica vagans – Schoenus nigricans heath (H5) community, E. tetralix is onlyoccasional and confined to wetter soils (see sub-community H6d) with several preferentialassociates. The only herbaceous associates common throughout are Carex flacca, Potentillaerecta and Polygala vulgaris. The most commonand distinctive herbs of this community are Violariviniana, Filipendula vulgaris, Stachys betonica,Hypochoeris radicata, Agrostis canina ssp.montana, Dactylis glomerata and Scilla verna.Most of these species are found in recently burnedstands but become more scattered and reduced innumber as the vegetation and litter increase.
On shallower soils, especially when grazed, arich short herb layer is maintained with several additional species including Festuca ovina,
Thymus praecox, Lotus corniculatus, Galiumverum, Jasione montana, Danthonia decumbensand Brachypodium sylvaticum. Immediately afterburning, diversity is increased, with ephemeralsincluding Aira caryophyllea and Centaurium erythraea. Continued burning and the dense shadeand litter of older stands inhibit bryophytes andlichens, which as a result are uncommon.
This community is confined to the Lizard inCornwall where it is characteristic of free-drainingbrown earths that are usually quite base-rich butcalcium-poor and fairly oligotrophic. It is foundon soils similar to that of H5 with a pH of general-ly between 5 and 7, but which are more free-drain-ing. Therefore it is typically found on the steeper,shedding slopes around coves and on the cliff topsof the headlands. Although it is mainly coastal in distribution it is not strictly speaking a maritimeheath and is replaced on slopes which are exposed to salt spray by Calluna vulgaris –Scilla verna heath (H7).
Edaphic variation and local differences in thewarm oceanic climate strongly influence floristicdiversity, but treatments, especially burning, andto a lesser extent grazing, also have a marked effecton composition and physiognomy of the vegeta-tion. However, the progression to scrub and wood-land in the absence of these treatments wouldprobably be slow due to the lack of seed parentsand the poor quality of the soil. Preferential culti-vation of the more fertile soils developed over gab-bro and schists means that the community sur-vives most extensively over serpentine.
H6 Erica vagans – Ulexeuropaeus heath
87
Fil
ipen
du
la v
ulg
aris
ver
y fr
equ
ent
but
Mol
inia
cae
rule
a ab
sen
t an
d P
oten
till
aer
ecta
an
d S
erra
tula
tin
ctor
ia o
nly
occa
sion
al.
Mol
inia
cae
rule
a an
d P
oten
till
a er
ecta
con
stan
t w
ith
Ser
ratu
la t
inct
oria
fre
-qu
ent,
bu
t F
ilip
end
ula
vu
lgar
is r
ath
eru
nco
mm
on.
Agr
osti
s cu
rtis
ii a
nd
ass
ocia
tes
list
ed o
pp
osit
e ab
sen
t, b
ut
Eri
cate
tral
ix c
onst
ant
in s
mal
lam
oun
ts a
nd
San
guis
orba
of
fici
nal
is a
nd
Sch
oen
us
nig
rica
ns
freq
uen
t.
H6d
Mol
inia
ca
eru
lea
sub-
com
mu
nit
y
Eri
ca v
agan
s an
d U
lex
euro
pae
us
reta
in h
igh
fre
quen
-cy
an
d a
bun
dan
ce w
ith
sm
alle
ram
oun
ts o
f U
lex
gall
ii. B
oth
Eri
ca c
iner
ea a
nd
Cal
lun
a vu
l-ga
ris
are
red
uce
d i
n f
requ
ency
but
Eri
ca t
etra
lix
is c
onst
ant
insm
all
amou
nts
. In
sta
nd
s n
otre
cen
tly
burn
ed M
olin
iaca
eru
lea
is d
isti
nct
ive.
It
s li
tter
dep
ress
es h
erbs
an
d g
ener
ally
only
Car
ex f
lacc
a,V
iola
riv
ini-
ana,
Pot
enti
lla
erec
ta a
nd
Sta
chys
bet
onic
a oc
cur
wit
han
y fr
equ
ency
, wit
h s
mal
lam
oun
ts o
f th
e p
refe
ren
tial
sli
sted
abo
ve.
H6c
Agr
osti
s cu
rtis
iisu
b-co
mm
un
ity
Ap
art
from
occ
asio
nal
occ
ur-
ren
ces
in H
6a, A
gros
tis
curt
isii
is l
arge
ly c
onfi
ned
to
this
su
b-co
mm
un
ity
wh
ere
it c
an b
eve
ry a
bun
dan
t es
pec
iall
y af
ter
burn
ing.
Mol
inia
cae
rule
a is
also
fre
quen
t an
d t
he
two
gras
s-es
som
etim
es d
omin
ate
un
der
an o
pen
can
opy
of E
rica
vaga
ns,
E. c
iner
ea,U
lex
gall
iian
d U
. eu
rop
aeu
s. A
mon
g th
eh
erbs
Vio
la r
ivin
ian
a is
abs
ent
and
Fil
ipen
du
la v
ulg
aris
sca
rce.
Dan
thon
ia d
ecu
mbe
ns
and
Pot
enti
lla
erec
ta a
re v
ery
fre-
quen
t an
d S
tach
ys b
eton
ica
and
Ser
ratu
la t
inct
oria
are
com
mon
,as
are
th
e p
refe
ren
tial
sp
ecie
sli
sted
abo
ve.
Agr
osti
s cu
rtis
iico
nst
ant
and
ofte
n a
bun
dan
t, p
arti
cula
rly
afte
r bu
rnin
g, w
ith
Cal
lun
a vu
l-ga
ris
scar
ce. C
arex
pan
icea
,H
yper
icu
m p
ulc
hru
m,V
iola
lact
ea a
nd
Pol
ygal
a se
rpyl
lifo
lia
freq
uen
t.
H6
H6a
Typ
ical
su
b-co
mm
un
ity
Typ
ical
hea
th w
ith
a c
omp
lete
ran
ge o
f fl
oris
tic
and
str
uct
ura
lve
geta
tion
rel
ated
to
burn
ing.
A f
ew y
ears
in
to t
he
cycl
e th
ere
is a
wel
l-d
evel
oped
su
b-sh
rub
can
opy
wit
h m
ost
of t
he
com
-m
un
ity
con
stan
ts. R
ich
er s
tan
ds
hav
e oc
casi
onal
Teu
criu
msc
orod
onia
an
d G
eran
ium
san
-gu
ineu
m, t
he
only
pre
fere
nti
ald
icot
yled
ons
her
e.
Wit
hin
crea
sin
g ag
e th
e co
nst
ant
her
bs b
egin
to
thin
ou
t le
avin
g a
den
se w
ood
y co
ver.
H6b
Fes
tuca
ovi
na
sub-
com
mu
nit
y
Her
e th
e ab
un
dan
ce a
nd
hei
ght
of t
he
sub-
shru
b ca
nop
y is
les
sth
an i
n t
he
typ
ical
for
m w
ith
ato
tal
cove
r of
oft
en l
ess
than
50%
. Ap
art
from
Pot
enti
lla
erec
ta t
he
com
mon
her
bs a
re a
llw
ell
rep
rese
nte
d i
n t
his
su
b-co
mm
un
ity.
In
th
e m
ore
open
con
dit
ion
s th
ere
are
mor
e cr
yp-
toga
ms
than
usu
al, H
ypn
um
cup
ress
ifor
me
s.l.
is f
requ
ent
and
var
iou
s C
lad
onia
sp
p.
com
mon
.
Su
b-sh
rub
can
opy
usu
ally
low
and
op
en w
ith
a r
ich
flo
rabe
twee
n t
he
bush
es i
ncl
ud
ing
Dan
thon
ia d
ecu
mbe
ns,
Koe
leri
am
acra
nth
a,A
ira
cary
oph
ylle
a,G
aliu
m v
eru
m a
nd
Leo
nto
don
tara
xaco
ides
as
con
stan
ts.
Su
b-sh
rub
can
opy
usu
ally
exte
nsi
ve w
ith
occ
asio
nal
Ru
bus
fru
tico
sus
agg.
, Pru
nu
ssp
inos
a an
d P
teri
diu
m a
quil
-in
um
,an
d s
catt
ered
Teu
criu
msc
orod
onia
an
d G
eran
ium
san
-gu
ineu
m,b
ut
asso
ciat
es l
iste
dop
pos
ite
very
sp
arse
in
mor
ere
cen
tly
rege
ner
atin
g st
and
s.
88
In this heath, sub-shrubs are a consistent feature,though they are not always obvious. The canopy istypically very short, rarely over 20 cm, and some-times when grazed forming a mat only 2-3 cmhigh. The cover of woody plants is rarely continu-ous. Even where sub-shrubs are more extensive,they are commonly penetrated by herbs. Callunavulgaris is the most frequent sub-shrub and thecommonest dominant, though on dry soils it isaccompanied by Erica cinerea. On wetter soils thelatter is much reduced and E. tetralix and/orEmpetrum nigrum ssp. nigrum are the usual asso-ciates. No other woody species occurs frequentlythroughout, although Ulex gallii is occasional.
Among herbaceous associates grasses are oftenimportant. Festuca ovina is the most frequentgrass species, though F. rubra is also common.Also common and a constant is Holcus lanatus,often with Dactylis glomerata on drier soils orDanthonia decumbens on moister ground. In wetter, northern heaths Agrostis capillaris andAnthoxanthum odoratum can become very common, but Molinia caerulea is infrequent.There are a variety of other herbs. Most distinctiveamong the constants are Plantago maritima andScilla verna. Other common and constant speciesare Plantago lanceolata, Potentilla erecta, Lotus
corniculatus, Thymus praecox and Hypochoerisradicata, the latter of which tends to favour driersoils. Anthyllis vulneraria also favours drier soilsas do Euphrasia species. Other species are morecharacteristic of particular sub-communities.
In contrast cryptogams are few and never show high cover. Among the mosses only Hypnumcupressiforme s.l. is moderately frequent andFrullania tamarisci, the commonest hepatic, isinfrequent. Several Cladonia species are occasional.
This community occurs over a wide variety ofmoderately base-poor soils on the less exposedparts of maritime cliffs all around the coast ofBritain except to the east and south betweenDurham and Dorset. The single most distinctivedifference between the habitat of this kind ofheath and the habitats of other sub-shrub commu-nities is the input of salt spray generated by break-ing waves and carried inland by the wind.
The floristic and structural variation in this community is influenced by the climatic andedaphic differences both throughout the consider-able geographic range of the community and overparticular stretches of cliff. Grazing also affects thecomposition and appearance of the vegetation andprobably contributes to maintaining it against suc-cessional change. However, over much of its rangethis vegetation can be considered a climatic cli-max as exposure to even small amounts of saltspray hinders the invasion of woody invaders.
H7 Calluna vulgaris –Scilla verna heath
89
Agr
osti
s ca
pil
lari
s an
d A
nth
oxan
thu
mod
orat
um
occ
asio
nal
bu
t E
rica
cin
erea
and
Hyp
och
oeri
s ra
dic
ata
rem
ain
ver
yfr
equ
ent
and
E. t
etra
lix,
Em
pet
rum
nig
rum
,Car
ex p
anic
ea a
nd
C. n
igra
ar
e ra
re.
Eri
ca c
iner
ea a
nd
Hyp
och
oeri
s ra
dic
ata
red
uce
d i
nfr
equ
ency
bu
t E
rica
tet
rali
x an
d E
mp
etru
m n
igru
mco
mm
on. P
lan
tago
mar
itim
a an
d P
. lan
ceol
ata
ofte
nve
ry c
onsp
icu
ous.
An
thox
anth
um
od
orat
um
an
dA
gros
tis
cap
illa
ris
freq
uen
t an
d C
arex
pan
icea
an
dC
arex
nig
ra o
ccas
ion
al.
Em
pet
rum
nig
rum
con
stan
t,w
ith
Eri
ca t
etra
lix,
Dan
thon
iad
ecu
mbe
ns
and
Su
ccis
a p
rate
n-
sis
only
ver
y oc
casi
onal
bu
tTr
ifol
ium
rep
ens
and
Lu
zula
mu
ltif
lora
qu
ite
com
mon
.
H7d
Em
pet
rum
nig
rum
ssp
. nig
rum
sub-
com
mu
nit
y
Th
is t
ype
of h
eath
sh
ares
se
vera
l fe
atu
res
wit
h H
7c; E
rica
cin
erea
is
seld
om f
oun
d b
ut
isre
pla
ced
her
e by
Em
pet
rum
nig
rum
wh
ich
is
ofte
n c
o-d
omi-
nan
t w
ith
Cal
lun
a vu
lgar
is.
Eri
ca t
etra
lix
and
Ule
x sp
ecie
sar
e ra
re. F
estu
ca o
vin
a,F.
ru
bra,
Agr
osti
s ca
pil
lari
s an
dA
nth
oxan
thu
m o
dor
atu
m a
refr
equ
ent
and
Car
ex p
anic
eaco
mm
on. A
mon
g d
icot
yled
ons
Pla
nta
go m
arit
ima
and
P. l
ance
-ol
ata
are
very
fre
quen
t an
dT
hym
us
pra
ecox
an
d L
otu
s co
rnic
ula
tus
com
mon
, wh
ile
Hyp
och
oeri
s ra
dic
ata
is v
ery
rare
on
th
e m
oist
soi
ls.
Th
is s
ub-
com
mu
nit
y is
fou
nd
pre
dom
inan
tly
in n
orth
ern
Bri
tain
.
H7c
Eri
ca t
etra
lix
sub-
com
mu
nit
y
Two
feat
ure
s d
isti
ngu
ish
th
isty
pe
of h
eath
. Fir
st, a
mon
g th
e su
b-sh
rubs
Eri
ca c
iner
ea i
sm
uch
red
uce
d a
nd
rep
lace
d b
yE
rica
tet
rali
x as
th
e u
sual
com
-p
anio
n t
o C
allu
na
vulg
aris
. Th
eca
nop
y is
typ
ical
ly e
xten
sive
,bu
t sh
ort
beca
use
of
graz
ing.
Sec
ond
ly, a
lth
ough
gra
sses
are
pro
min
ent
Fes
tuca
ovi
na
isof
ten
rep
lace
d b
y F
estu
ca r
ubr
aas
th
e m
ost
abu
nd
ant
spec
ies
and
Agr
osti
s ca
pil
lari
s,A
nth
oxan
thu
m o
dor
atu
m a
nd
Dan
thon
ia d
ecu
mbe
ns
are
very
com
mon
an
d s
omet
imes
co-
dom
inan
t. P
lan
tago
mar
itim
a is
ofte
n a
bun
dan
t w
ith
P. l
ance
o-la
ta c
omm
on.
Th
is s
ub-
com
mu
nit
y is
mos
tp
rom
inen
t on
th
e n
orth
-wes
tco
ast
of B
rita
in, p
arti
cula
rly
inth
e H
ebri
des
an
d S
uth
erla
nd
,w
ith
sca
tter
ed o
ccu
rren
ces
dow
n t
o A
ngl
esey
.
Eri
ca t
etra
lix
con
stan
t w
ith
occa
sion
al E
mp
etru
m n
igru
man
d f
requ
ent
Dan
thon
ia d
ecu
m-
ben
s an
d S
ucc
isa
pra
ten
sis.
Mol
inia
cae
rule
a,N
ard
us
stri
cta
and
Sal
ix r
epen
s lo
call
y p
rom
inen
t.
H7
Dac
tyli
s gl
omer
ata
and
An
thyl
lis
vuln
erar
ia o
ccas
ion
albu
t ot
her
lis
ted
ass
ocia
tes
rare
.
H7a
Arm
eria
ma
riti
ma
sub-
com
mu
nit
y
Her
e, w
her
e sa
lt-s
pra
y d
epos
i-ti
on i
s h
igh
, th
e ca
nop
y of
su
b-sh
rubs
is
gen
eral
ly l
ess
exte
n-
sive
, eit
her
wit
h a
mos
aic
ofop
en a
reas
or
red
uce
d t
o d
is-
cret
e p
atch
es o
f bu
shes
. Th
eon
ly c
omm
on s
ub-
shru
bs a
reC
allu
na
vulg
aris
an
d E
rica
cin
erea
, alt
hou
gh t
he
latt
er i
sre
du
ced
in
exp
osed
sit
uat
ion
s.G
row
ing
amon
g an
d b
etw
een
the
bush
es i
s F
estu
ca o
vin
a as
the
dom
inan
t, s
omet
imes
wit
hF.
ru
bra,
freq
uen
tly
wit
h H
olcu
sla
nat
us
and
Dac
tyli
s gl
omer
ata.
Ap
art
from
Pot
enti
lla
erec
ta,
wh
ich
is
scar
ce, a
ll o
ther
com
-m
un
ity
con
stan
ts a
nd
th
e as
so-
ciat
es l
iste
d a
bove
are
wel
l re
p-
rese
nte
d.
Th
is s
ub-
com
mu
nit
y, a
lon
gw
ith
th
e V
iola
su
b-co
mm
un
ity,
occu
rs t
hro
ugh
out
the
ran
ge o
fH
7 bu
t is
bet
ter
dev
elop
ed t
oth
e so
uth
of
Gal
low
ay w
ith
on
lylo
cal
stat
ion
s be
yon
d t
his
.
Arm
eria
mar
itim
aan
d S
edu
man
glic
um
con
stan
t an
d o
ften
abu
nd
ant
wit
h f
requ
ent
Dac
tyli
sgl
omer
ata,
An
thyl
lis
vuln
erar
iaan
d J
asio
ne
mon
tan
a,an
d o
cca-
sion
al P
lan
tago
cor
onop
us
and
Sil
ene
vulg
aris
mar
itim
a.
Vio
la r
ivin
ian
a oc
casi
onal
bu
t ot
her
lis
ted
ass
ocia
tes
rare
amon
g an
oft
en i
mp
over
ish
edC
allu
na
vulg
aris
-dom
inat
edco
ver.
Vio
la r
ivin
ian
a,P
olyg
ala
vulg
aris
,Car
ex f
lacc
a an
d
C. c
aryo
ph
ylle
a fr
equ
ent.
Ach
ille
a m
ille
foli
um
,Leo
nto
don
tara
xaco
ides
,Gal
ium
ver
um
,S
tach
ys b
eton
ica
and
Ser
ratu
lati
nct
oria
occ
asio
nal
an
d E
rica
vaga
ns
and
Ule
x eu
rop
aeu
slo
call
y p
rom
inen
t.
H7e
Ca
llu
na
vu
lga
ris
sub-
com
mu
nit
y
In g
ener
al f
lori
stic
s th
is h
eath
typ
e re
sem
bles
im
pov
eris
hed
vers
ion
s of
th
e A
rmer
ia a
nd
Vio
lasu
b-co
mm
un
itie
s th
ough
usu
ally
wit
h a
tal
ler
can
opy.
Cal
lun
a vu
lgar
isis
th
e u
sual
dom
inan
t th
ough
Eri
ca c
iner
eais
com
mon
; all
oth
er s
ub-
shru
bsar
e sc
arce
. Fes
tuca
ovi
na
is
the
mos
t fr
equ
ent
gras
s w
ith
F. r
ubr
a le
ss c
omm
on.
Hyp
och
oeri
s ra
dic
ata
is q
uit
efr
equ
ent
but
rose
tte
her
bs a
rep
oorl
y re
pre
sen
ted
in
th
e ra
nk
her
bage
. Th
ymu
s p
raec
ox a
nd
Lotu
s co
rnic
ula
tus,
alth
ough
com
mon
are
oft
en n
ot
abu
nd
ant.
Th
is s
ub-
com
mu
nit
y is
fou
nd
thro
ugh
out
the
ran
ge o
f H
7 bu
tis
rar
er t
o th
e n
orth
, alt
hou
gh i
tis
wel
l-re
pre
sen
ted
in
Sh
etla
nd
.
H7b
Vio
la r
ivin
ian
asu
b-co
mm
un
ity
Th
e su
b-sh
rub
can
opy
is m
ore
exte
nsi
ve t
han
in
H7a
wit
h b
oth
Cal
lun
a vu
lgar
is a
nd
Eri
caci
ner
ea v
ery
freq
uen
t an
d o
ften
co-d
omin
ant.
Eri
ca t
etra
lix
and
Em
pet
rum
nig
rum
are
typ
ical
lyve
ry s
carc
e. T
he
her
bace
ous
pla
nts
are
mos
t d
isti
nct
ive.
All
the
com
mu
nit
y co
nst
ants
are
wel
l re
pre
sen
ted
tog
eth
er w
ith
the
spec
ies
list
ed a
bove
.
Th
is s
ub-
com
mu
nit
y, a
lon
gw
ith
th
e A
rmer
ia s
ub-
com
mu
ni-
ty, o
ccu
rs t
hro
ugh
out
the
ran
geof
H7
but
is b
ette
r d
evel
oped
sou
th o
f G
allo
way
wit
h o
nly
loca
l st
atio
ns
nor
th o
f th
is.
90
Floristically this is a diverse community with onlythree constants overall, namely Calluna vulgaris,Erica cinerea and Ulex gallii. Erica tetralix,Molinia caerulea and Agrostis curtisii are typical-ly lacking from this community. Often the threeconstant sub-shrubs are co-dominant, but propor-tions are variable and where E. cinerea is reducedVaccinium myrtillus can appear. On disturbedground U. europaeus may be abundant and bothPteridium aquilinum and Rubus fruticosus agg.may appear in the heath.
Typically sub-shrub cover is high and herbs aresparse, but often the bushes are separated bygrassy runnels, a feature accentuated by grazing.The most frequent grasses are Agrostis capillarisand Festuca ovina with A. canina ssp. montana,F. rubra, Anthoxanthum odoratum and Danthoniadecumbens occasional to frequent. Deschampsiaflexuosa and Nardus stricta are much more patchyin their occurrence. There is often some Potentillaerecta and Galium saxatile, and much more occasionally Teucrium scorodonia and Polygalaserpyllifolia. Additional herbs are characteristic ofparticular sub-communities.
In general bryophytes and lichens are notnumerous or diverse. There may be some Hypnumcupressiforme and Dicranum scoparium, and
Rhytidiadelphus squarrosus and Pleuroziumschreberi are more occasional. In more open situations, or on burned or disturbed bare ground,mosses such as Campylopus paradoxus, Poly-trichum piliferum or P. juniperinum can becomeabundant along with lichens species such asCladonia impexa and C. squamosa.
This community is found on free-draining, generally acid to circumneutral soils, in the warmoceanic regions of lowland Britain. It can be foundover a wide range of arenaceous sedimentaries andacid igneous and metamorphic rocks as well as onsilty and sandy superficials like loess and aeoliansands. The superficial pH underneath this com-munity is usually from 3.5 to 4.5. It occursthroughout south-western England and Wales, onthe Isle of Man and, more sporadically, in thesouthern Pennine fringes and the East Angliancoast.
Local climatic and edaphic conditions influencefloristic variation; grazing by rabbits, sheep or cattle, and sometimes burning (which is normallyan accidental occurrence), affect physiognomy andcomposition. The community is maintained againstsuccession to woodland in most situations by graz-ing and burning, although in some situations expo-sure to the wind prevents the establishment ofwoody invaders such as Betula spp. and Quercusspp. Much former heath has been improved foragriculture and it now often survives as patches onmarginal grazing land.
H8 Calluna vulgaris –Ulex gallii heath
91
Pot
enti
lla
erec
ta c
an b
e qu
ite
com
mon
,bu
t ot
her
sp
ecie
s li
sted
op
pos
ite
are
scar
ce.
Dan
thon
ia d
ecu
mbe
ns,
An
thox
anth
um
odor
atu
m,F
estu
ca r
ubr
a an
d P
oten
till
aer
ecta
fre
quen
t.
Com
bin
atio
ns
of s
pec
ies
list
edop
pos
ite
not
pre
sen
t.
H8b
Da
nth
onia
dec
um
ben
ssu
b-co
mm
un
ity
Th
e ca
nop
y is
wel
l-d
evel
oped
her
e w
ith
Ule
x ga
llii
an
d E
rica
cin
erea
esp
ecia
lly
abu
nd
ant,
but
not
as
den
se a
s in
H8a
an
dty
pic
ally
th
ere
is a
sys
tem
of
gras
sy r
un
nel
s. I
n t
hes
e A
gros
tis
cap
illa
ris
and
Fes
tuca
ovi
na
are
quit
e fr
equ
ent
but
mor
e ch
arac
-te
rist
ic i
s D
anth
onia
dec
um
ben
san
d l
ess
com
mon
ly A
nth
ox-
anth
um
od
orat
um
, Fes
tuca
rubr
a an
d A
gros
tis
can
ina
mon
-ta
na.
Mix
ture
s of
th
ese
spec
ies
typ
ical
ly f
orm
th
e bu
lk o
f a
rou
gh c
over
bet
wee
n t
he
bush
-es
. Car
ex p
ilu
life
ra i
s al
so t
ypi-
cal
but
pat
chy,
th
ough
par
ticu
-la
rly
abu
nd
ant
in o
pen
pla
ces
afte
r bu
rnin
g, a
nd
Vio
la l
acte
aca
n a
lso
beco
me
pro
min
ent
in
such
pla
ces.
Th
is s
ub-
com
mu
nit
y oc
curs
thro
ugh
out
the
ran
ge o
f H
8 bu
tis
bet
ter
rep
rese
nte
d i
n t
he
wes
t.
H8c
Sa
ngu
isor
ba
min
orsu
b-co
mm
un
ity
Th
is i
s th
e m
ost
stri
kin
g of
th
esu
b-co
mm
un
itie
s, d
evel
opin
gon
mor
e ca
lcar
eou
s so
ils.
Th
esu
b-sh
rubs
an
d s
tru
ctu
ral
vari
a-ti
on a
re s
imil
ar t
o th
ose
of H
8b.
Wit
h t
hem
, how
ever
, is
a gr
oup
of s
tron
gly
pre
fere
nti
al h
erbs
,li
sted
abo
ve. W
her
e n
um
bers
of
th
ese
are
pre
sen
t in
gra
zed
stan
ds
the
vege
tati
on c
an l
ook
like
Mes
obro
mio
n g
rass
lan
dgr
owin
g am
ong
isla
nd
s of
th
eh
eath
su
b-sh
rubs
.
Th
is s
ub-
com
mu
nit
y is
fou
nd
in
area
s w
ith
cal
care
ous
bed
rock
man
tled
wit
h d
rift
.
San
guis
orba
min
or,C
arex
fla
c-ca
,Hel
ian
them
um
nu
mm
ula
ri-
um
an
d P
lan
tago
lan
ceol
ata
fre-
quen
t, w
ith
occ
asio
nal
Gal
ium
veru
m,L
otu
s co
rnic
ula
tus,
Car
ex c
aryo
ph
ylle
a,Li
nu
mca
thar
ticu
m,B
rach
ypod
ium
syl
-va
ticu
m,H
yper
icu
m p
ulc
hru
man
d S
tach
ys b
eton
ica.
H8
Sp
ecie
s li
sted
op
pos
ite
usu
ally
very
sca
rce.
H8d
Sci
lla
ver
na
sub-
com
mu
nit
y
Th
e th
ree
con
stan
t su
b-sh
rubs
are
typ
ical
ly e
xten
sive
as
co-
dom
inan
ts. T
her
e is
a r
ath
ersp
ecie
s-p
oor
her
bace
ous
ele-
men
t w
ith
Fes
tuca
ovi
na
the
mos
t fr
equ
ent,
an
d o
ften
th
eon
ly, g
rass
. Pot
enti
lla
erec
tare
mai
ns
com
mon
wh
ile
Hyp
och
oeri
s ra
dic
ata
is m
ore
dis
tin
ctiv
e an
d p
refe
ren
tial
wit
h S
cill
a ve
rna.
P
lan
tago
mar
itim
a ca
n o
ccu
r fr
equ
entl
yan
d m
ay b
e ab
un
dan
t in
agr
azed
sw
ard
.
Th
is s
ub-
com
mu
nit
y is
con
-fi
ned
to
the
coas
tal
frin
ge i
nw
este
rn B
rita
in.
Sci
lla
vern
a,P
lan
tago
mar
itim
a,H
ypoc
hoe
ris
rad
icat
aan
dT
hym
us
pra
ecox
freq
uen
t.
Eri
ca c
iner
ea r
emai
ns
com
mon
but
Vac
cin
ium
myr
till
us
and
oth
er s
pec
ies
list
ed o
pp
osit
esc
arce
.
H8a
Sp
ecie
s-p
oor
sub-
com
mu
nit
y
Th
ere
is a
n e
xten
sive
an
d d
ense
sub-
shru
b ca
nop
y. T
he
can
opy
can
be
quit
e ta
ll, t
hic
ker
stan
ds
bein
g le
ss p
enet
rabl
e to
liv
e-st
ock.
Th
e as
soci
ated
flo
ra i
sve
ry s
par
se w
ith
gra
sses
su
ch
as A
gros
tis
cap
illa
ris,
Fes
tuca
ovin
a an
d F
. ru
bra
red
uce
d t
osm
all
tuft
s w
ith
occ
asio
nal
an
d w
eak
Pot
enti
lla
erec
ta
and
Gal
ium
sax
atil
e. W
her
e th
e ca
nop
y is
op
ened
by
dis
turb
ance
or
burn
ing
Ule
xeu
rop
aeu
s or
Pte
rid
ium
aqu
il-
inu
m m
ay e
xpan
d.
Cry
pto
gam
sar
e ge
ner
ally
in
freq
uen
t w
ith
a
few
pat
ches
of
Hyp
nu
mcu
pre
ssif
orm
e.
Th
is s
ub-
com
mu
nit
y oc
curs
thro
ugh
out
the
ran
ge o
f H
8.
H8e
Va
ccin
ium
myr
till
us
sub-
com
mu
nit
y
Eri
ca c
iner
ea i
s p
rese
nt
wit
hre
du
ced
fre
quen
cy, t
hou
gh i
tca
n r
emai
n l
ocal
ly a
bun
dan
t in
th
is u
pla
nd
su
b-co
mm
un
ity.
Th
e m
ost
pro
min
ent
sub-
shru
bis
usu
ally
Ule
x ga
llii
wit
hsm
alle
r am
oun
ts o
f C
allu
na
vulg
aris
an
d, s
tron
gly
dia
gnos
tic,
Vac
cin
ium
myr
till
us.
Gra
sses
can
hav
e a
hig
h c
over
, wit
hA
gros
tis
cap
illa
ris,
Fes
tuca
ovin
a an
d A
nth
oxan
thu
m
odor
atu
m a
ll f
requ
ent,
bu
tD
esch
amp
sia
flex
uos
a is
pre
fer-
enti
al. N
ard
us
stri
cta
can
als
ooc
cur
wit
h l
ocal
abu
nd
ance
bu
td
icot
yled
onou
s as
soci
ates
are
few
. Gal
ium
sax
atil
e an
dD
igit
alis
pu
rpu
rea
are
occa
sion
-al
. In
mor
e op
en s
itu
atio
ns
bryo
ph
ytes
can
for
m a
lu
sh
but
pat
chy
cove
r.
Th
is s
ub-
com
mu
nit
y is
fou
nd
mai
nly
in
th
e u
pla
nd
fri
nge
s.
Eri
ca c
iner
ea r
edu
ced
in
fre
-qu
ency
bu
t V
acci
niu
m m
yrti
llu
sco
nst
ant
in s
mal
l am
oun
ts w
ith
Des
cham
psi
a fl
exu
osa
freq
uen
tan
d N
ard
us
stri
cta,
Ple
uro
ziu
msc
hre
beri
an
d R
hyt
idia
del
ph
us
squ
arro
sus
occa
sion
al.
92
Calluna vulgaris is almost always the most abundant plant in this community, often forming afairly low and open canopy. Where burning is frequent, the individuals are immature and standsare uniform in age. No other sub-shrubs are consistently frequent throughout, although somecan be quite common and locally abundant.Vaccinium myrtillus is the most important, particularly at higher altitudes. More locally V. vitis-idaea and Empetrum nigrum ssp. nigrumcan be found. Erica cinerea, E. tetralix and Ulexgallii by contrast are very scarce.
The only other vascular constant isDeschampsia flexuosa, although even in openheather it often occurs only as sparse tufts, andunder dense canopies it can almost disappear.Molinia caerulea can become frequent on moisterground, but Agrostis capillaris, Holcus lanatus,H. mollis and Festuca rubra only occur occasion-ally. Other herbs are also few and are of low cover.Galium saxatile and Potentilla erecta are frequentin grazed stands and Juncus squarrosus andPteridium aquilinum occasionally occur. Seed-lings of Quercus spp., Betula spp. and Pinussylvestris may be seen but rarely survive to thesapling stage due to frequent burning and grazing.
The bryophyte and lichen flora is characteristic,although poor in species. Hypnum cupressiformes.l. is restricted, but Pohlia nutans is constant andvery common with occasional Campylopus paradoxus and Dicranum scoparium. Ortho-
dontium lineare may be frequent. On exposed soilthere can be locally abundant Polytrichum juniper-inum, P. piliferum and P. commune. Among leafyhepatics Gymnocolea inflata is particularly charac-teristic. The commonest lichens are Cladoniachlorophaea, C. floerkeana, C. squamosa, C. coni-ocraea and C. fimbriata.
This heath is the characteristic sub-shrub vegetation of acid and impoverished soils at lowto moderate altitudes through the Midlands andnorthern England. It is normally found on verybase-poor soils with a surface acidity generally ofpH 3-4, highly oligotrophic and at least moderate-ly free-draining, often excessively so, which havebeen derived from a wide variety of parent materi-als. It is found mainly in the southern Penninesand North York Moors with more local occur-rences scattered through the Midland plain.
The cool and wet climate has some influenceon the floristics of this community, but much of itscharacter derives from a combination of frequentburning and grazing. Also the heavy atmosphericpollution in the areas in which this heath occursis thought to inhibit bryophyte and lichen diversi-ty of the community. The community has beenreduced considerably in extent. In the lowlandslarge tracts of heath have been reclaimed for agri-culture whilst other areas have been lost to inva-sion by trees after the neglect of traditional treat-ments. Furthermore, both in the lowlands andaround the upland fringes, the community hasbeen replaced with coniferous plantations, or land use changes have led to the spread of U20 Pteridium aquilinum – Galium saxatilecommunity.
H9 Calluna vulgaris –Deschampsia flexuosa heath
93
Vac
cin
ium
myr
till
us
and
Cam
pyl
opu
sp
arad
oxu
sat
mos
t oc
casi
onal
, an
dot
her
sp
ecie
s li
sted
op
pos
ite
rare
.
H9b
Va
ccin
ium
myr
till
us
–C
lad
onia
spp
. su
b-co
mm
un
ity
Th
is i
s th
e ri
ches
t su
b-co
mm
u-
nit
y ch
arac
teri
sed
by
you
nge
rca
nop
ies
of h
eath
er, o
ften
reco
veri
ng
from
bu
rnin
g. T
her
ear
e fr
equ
entl
y on
e or
mor
e of
the
sub-
shru
bs l
iste
d a
bove
.O
ften
Des
cham
psi
a fl
exu
osa
has
a r
ath
er l
ow c
over
. Am
ong
the
sub-
shru
bs, b
ryop
hyt
es a
rem
ore
vari
ed t
han
in
an
y ot
her
typ
e of
th
is h
eath
. Poh
lia
nu
tan
s,C
amp
ylop
us
par
adox
us
and
Ort
hod
onti
um
lin
eare
all
occu
r fr
equ
entl
y an
d t
he
leaf
y h
epat
ics
and
lic
hen
s li
sted
abov
e ar
e oc
casi
onal
to
fre-
quen
t.
Th
is a
nd
th
e sp
ecie
s-p
oor
sub-
com
mu
nit
y ar
e th
e u
sual
for
ms
in t
he
sou
ther
n P
enn
ines
an
dth
e N
orth
Yor
k M
oors
an
d a
rew
ides
pre
ad a
nd
som
etim
esex
ten
sive
ove
r h
eath
lan
ds
that
are
stil
l fr
equ
entl
y bu
rned
.
H9
Mol
inia
cae
rule
a ab
sen
t.
H9c
Sp
ecie
s-p
oor
sub-
com
mu
nit
y
In t
his
, th
e m
ost
imp
over
ish
edfo
rm, C
allu
na
vulg
aris
an
dD
esch
amp
sia
flex
uos
a ar
e th
eon
ly c
onst
ants
, an
d i
n f
requ
ent-
ly b
urn
ed h
eath
er e
ven
th
e la
tter
can
alm
ost
dis
app
ear.
Vac
cin
ium
myr
till
us
is
occa
sion
al. P
ohli
a n
uta
ns,
Cam
pyl
opu
s p
arad
oxu
s an
dO
rth
odon
tiu
m l
inea
re a
ll s
how
red
uce
d f
requ
enci
es c
omp
ared
wit
h H
9b.
Th
is a
nd
th
e V
acci
niu
m s
ub-
com
mu
nit
y ar
e th
e u
sual
for
ms
in t
he
sou
ther
n P
enn
ines
an
dth
e N
orth
Yor
k M
oors
, an
d a
rew
ides
pre
ad a
nd
som
etim
esex
ten
sive
ove
r h
eath
lan
ds
that
are
stil
l fr
equ
entl
y bu
rned
.
H9a
Hyp
nu
m c
up
ress
ifor
me
sub-
com
mu
nit
y
Cal
lun
ais
typ
ical
ly s
tron
gly
dom
inan
t bu
t ex
cep
tion
ally
th
ebu
shes
ten
d t
o be
lar
ge a
nd
mat
ure
or
even
deg
ener
ate.
Vac
cin
ium
myr
till
us
and
Pte
rid
ium
aqu
ilin
um
are
bot
hoc
casi
onal
an
d t
her
e ar
e fr
e-qu
ent,
eve
n d
ense
tu
fts
ofD
esch
amp
sia
flex
uos
a. T
he
mos
ses
are
mos
t d
isti
nct
ive;
Hyp
nu
m c
up
ress
ifor
me
s.l.
is
un
usu
ally
com
mon
an
d a
bun
-d
ant
wit
h D
icra
nu
m s
cop
ariu
mal
so p
refe
ren
tial
an
d f
requ
entl
yri
vall
ing
Poh
lia
nu
tan
s in
its
cove
r. A
par
t fr
om o
ccas
ion
alH
ypog
ymn
ia p
hys
odes
gro
win
gon
old
er C
allu
na
vulg
aris
,li
chen
s ar
e ve
ry f
ew.
Th
is s
ub-
com
mu
nit
y is
mai
nly
fou
nd
on
wet
ter
soil
s, a
nd
alo
ng
wit
h t
he
Gal
ium
an
d M
olin
iasu
b-co
mm
un
itie
s, i
s p
rim
aril
yfo
un
d o
n l
owla
nd
sit
es w
her
ebu
rnin
g is
no
lon
ger
pra
ctis
ed.
Mol
inia
cae
rule
a co
nst
ant
atlo
w c
over
.
H9e
Mol
inia
ca
eru
lea
sub-
com
mu
nit
y
Cal
lun
ais
gen
eral
ly v
ery
abu
n-
dan
t, b
ut
Des
cham
psi
a fl
exu
osa
is f
requ
entl
y ac
com
pan
ied
by
sm
all
amou
nts
of
Mol
inia
caer
ule
a. T
he
grou
nd
lay
er,
how
ever
, is
poo
rly
dev
elop
edw
ith
just
ver
y sp
arse
Poh
lia
nu
tan
s an
d C
amp
ylop
us
par
a-d
oxu
s.
Th
is s
ub-
com
mu
nit
y is
mai
nly
fou
nd
on
wet
ter
soil
s, a
nd
alo
ng
wit
h t
he
Gal
ium
an
d H
ypn
um
sub-
com
mu
nit
ies,
is
pri
mar
ily
fou
nd
on
low
lan
d s
ites
wh
ere
burn
ing
is n
o lo
nge
r p
ract
ised
.
H9d
Ga
liu
m s
axa
tile
sub-
com
mu
nit
y
Cal
lun
a vu
lgar
isre
mai
ns
con
stan
t bu
t is
oft
en r
ival
led
in
cov
er b
y D
esch
amp
sia
flex
uos
a,an
d s
tan
ds
are
loca
lly
enri
ched
by
a li
ttle
Hol
cus
mol
-li
s or
Fes
tuca
ru
bra.
Com
mon
lyth
ere
are
scat
tere
d p
lan
ts o
rp
rom
inen
t p
atch
es o
f G
aliu
msa
xati
le a
nd
sca
tter
ed P
oten
till
aer
ecta
wit
h R
um
ex a
ceto
sell
aon
bar
e ar
eas.
Lic
hen
s an
dh
epat
ics
are
spar
se a
nd
am
ong
the
mos
ses
only
Poh
lia
nu
tan
san
d H
ypn
um
cu
pre
ssif
orm
e s.
l. o
ccu
r m
ore
than
ver
y oc
casi
onal
ly.
Th
is s
ub-
com
mu
nit
y is
mai
nly
fou
nd
on
wet
ter
soil
s, a
nd
alo
ng
wit
h t
he
Mol
inia
an
d H
ypn
um
sub-
com
mu
nit
ies,
is
pri
mar
ily
fou
nd
on
low
lan
d s
ites
wh
ere
burn
ing
is n
o lo
nge
r p
ract
ised
.
Des
cham
psi
a fl
exu
osa
ofte
nes
pec
iall
y ab
un
dan
t w
ith
occ
a-si
onal
Hol
cus
mol
lis
and
Fes
tuca
ru
bra;
Gal
ium
sax
atil
ean
d P
oten
till
a er
ecta
fre
quen
tw
ith
occ
asio
nal
Ru
mex
ace
-to
sell
a.
Des
cham
psi
a fl
exu
osa
may
be
abu
nd
ant
but
not
wit
h a
ssoc
i-at
es l
iste
d o
pp
osit
e.
Hyp
nu
m c
up
ress
ifor
me
and
Dic
ran
um
sco
par
ium
com
mon
and
som
etim
es a
bun
dan
t.
Cal
luna
vul
gari
s an
d D
esch
amps
iafl
exu
osa
ofte
n t
he
only
pla
nts
,w
ith
occ
asio
nal
Poh
lia
nu
tan
s.
Vac
cin
ium
myr
till
us
or, m
ore
loca
lly,
V. v
itis
-id
aea,
V. i
nte
r-m
ediu
m o
r E
mp
etru
m n
igru
mco
mm
on o
r lo
call
y ab
un
dan
tw
ith
occ
asio
nal
to
freq
uen
tC
amp
ylop
us
par
adox
us,
Gym
noc
olea
in
flat
a,B
arbi
lop
hoz
ia f
loer
kii,
Cla
don
ia c
hlo
rop
hae
a,C
. flo
erke
ana
and
C. s
quam
osa.
94
This community is typically dominated byCalluna vulgaris, but the cover, height and structure of the sub-shrub canopy vary markedlydepending on the intensity and timing of burningand grazing. Erica cinerea, a constant, is frequentbut generally subordinate to heather and persistsbelow taller Calluna canopies. Vaccinium myrtillus, by contrast, is at most occasional and V. vitis-idaea is scarce. Empetrum nigrum ssp.nigrum can occur, but mainly in sub-communityH10b. The restricted occurrence of these sub-shrubs is a contrast with Calluna vulgaris –Vaccinium myrtillus heath (H12).
Apart from the abundance of the two constant sub-shrubs there are two other distinctive floristicfeatures of this type of heath. These are firstly thehigh frequency of grasses and to a lesser extentsedges and dicotyledons, and secondly the striking contribution that the ground layer makesto this community. Deschampsia flexuosa is themost consistent grass throughout, with Agrostiscanina and Nardus stricta occasional to frequent.In certain sub-communities Festuca ovina,Anthoxanthum odoratum, Agrostis capillaris andMolinia caerulea become very common. Carexbinervis and C. pilulifera are very characteristic ofthis community. After burning, mixtures of theseplants can become patchily abundant andDeschampsia flexuosa and C. pilulifera temporar-ily dominant. There are typically only a fewdicotyledons, but Potentilla erecta is a constant and Galium saxatile is fairly common.
After burning, a local abundance of Polytrichumpiliferum, P. juniperinum and encrusting Cladonia
species can develop. In exposed stands there isoften a patchy carpet of Racomitrium lanuginosumand fruticose lichens. However, more importantthan these species in the community as a whole arebulky pleurocarpous mosses such as Hypnumcupressiforme s.l., Pleurozium schreberi andHylocomium splendens, with Rhytidiadelphus tri-quetrus and R. loreus also occurring occasionally.These species, with Dicranum scoparium, becomeabundant with the maturing and opening up of theCalluna bushes.
This heath is characteristic of acid to circum-neutral and generally free-draining soils in thecool oceanic lowlands and upland fringes ofnorthern and western Britain. The soils on whichthis community is found can be quite moist as aresult of the climate and the superficial pHbeneath the community can be anywhere between3.5 and 6. It occurs widely through the moreoceanic parts of Scotland, with outlying stands inWales, western England and around the east-central Highlands.
In more exposed situations it may be consideredas an edaphic or climatic climax, but often burning and grazing are important in controlling itscomposition and structure. Steady grazing pressurepushes the vegetation towards the Festuca ovina –Agrostis capillaris – Galium saxatile grassland (U4)or, over more base-rich soils, the Festuca ovina –Agrostis capillaris – Thymus praecox grassland(CG10). After fire, heavy grazing can precipitate a run-down of the heath to swards in which Nardusstricta or Juncus squarrosus play an important partor permit the spread of Pteridium aquilinum.Release from grazing and burning, in all but themost exposed sites, would theoretically permit pro-gression to scrub and woodland, although in manyareas natural seed parents are now scarce.
H10 Calluna vulgaris – Ericacinerea heath
95
H10
Su
b-sh
rub
can
opy
ofte
n s
hor
t in
a g
rass
yh
eath
wit
h f
requ
ent
Fest
uca
ovi
na,
F. r
ubr
a,A
gros
tis
cap
illa
ris,
An
thox
anth
um
od
ora-
tum
an
d G
aliu
m s
axat
ile
and
occ
asio
nal
Cam
pan
ula
rot
un
dif
olia
,Su
ccis
a p
rate
nsi
san
d H
yper
icu
m p
ulc
hru
m.
Dic
ran
um
sco
-p
ariu
m,P
leu
rozi
um
sch
rebe
ri a
nd
Hyl
ocom
ium
sp
len
den
sp
atch
y.
H10
d
Th
ymu
s p
raec
ox–
Ca
rex
pu
lica
ris
sub-
com
mu
nit
y
Th
is h
eath
is
fou
nd
on
rel
ativ
ely
base
-ri
ch b
row
n e
arth
soi
ls a
nd
is
very
sim
-il
ar t
o H
10c
wit
h C
allu
na
vulg
aris
an
dE
rica
cin
erea
bot
h a
ble
to s
how
pro
mi-
nen
ce a
nd
wit
h h
erbs
an
d b
ryop
hyt
esbo
th b
ein
g of
str
uct
ura
l im
por
tan
ce.
Her
e th
ere
are
add
itio
nal
pre
fere
nti
als,
mak
ing
this
th
e m
ost
spec
ies-
rich
su
b-co
mm
un
ity.
Th
e sp
ecie
s li
sted
abo
vear
e m
ost
freq
uen
t to
geth
er w
ith
Car
exp
anic
ea a
nd
Th
ymu
s p
raec
ox. A
mon
gth
e br
yop
hyt
es D
icra
nu
m s
cop
ariu
man
d t
he
ple
uro
carp
s re
mai
n v
ery
com
-m
on; a
dd
itio
nal
ly R
hyt
idia
del
ph
us
triq
uet
rus
and
Bre
ute
lia
chry
soco
ma
are
freq
uen
t.
Th
is s
ub-
com
mu
nit
y is
loc
al i
n
occu
rren
ce b
ut
can
be
fou
nd
on
Sky
e,R
um
an
d U
ist
and
sca
tter
ed l
ocal
itie
sth
rou
gh t
he
Hig
hla
nd
s an
d S
outh
ern
Up
lan
ds.
H10
c
Fes
tuca
ovi
na
– A
nth
oxa
nth
um
od
ora
tum
sub-
com
mu
nit
y
Cal
lun
a vu
lgar
is i
s st
ill
abu
nd
ant
but
Eri
ca c
iner
ea m
ay o
ften
be
co-d
omi-
nan
t. T
he
sub-
shru
bs a
re u
sual
ly s
hor
t,co
mm
only
for
min
g a
mos
aic
wit
h a
gras
sy t
urf
. Mos
t fr
equ
ent
her
e ar
e th
egr
asse
s an
d o
ther
sp
ecie
s li
sted
abo
ve.
Car
ex b
iner
vis
and
C. p
ilu
life
ra a
real
so c
omm
on. D
icot
yled
onou
s h
erbs
are
mor
e n
um
erou
s th
an i
n 1
0a a
nd
10b.
Pot
enti
lla
erec
ta a
nd
Gal
ium
sa
xati
le a
re b
oth
ver
y co
mm
on w
ith
occa
sion
al r
ecor
ds
for
seve
ral
spec
ies
.B
ulk
y p
leu
roca
rpou
s m
osse
s ar
e co
n-
sist
ent
and
dis
tin
ctiv
e h
ere
wit
h f
re-
quen
t H
ypn
um
cu
pre
ssif
orm
e s.
l.,
Ple
uro
ziu
m s
chre
beri
,Hyl
ocom
ium
sple
nd
ens
and
als
o D
icra
nu
m
scop
ariu
m.
Th
is s
ub-
com
mu
nit
y is
com
mon
in
sou
th-w
est
Sco
tlan
d.
Dan
thon
ia d
ecu
mbe
ns
very
com
mon
wit
h o
ccas
ion
al t
o fr
equ
ent
Car
ex p
uli
cari
s, V
iola
rivi
nia
na,
Lin
um
cat
har
ticu
m,
Pru
nel
la v
ulg
aris
an
d P
rim
ula
vulg
aris
.
Com
bin
atio
ns
of s
uch
sp
ecie
s ra
re.
Com
bin
atio
ns
of s
uch
sp
ecie
s ra
re.
H10
a
Typ
ical
su
b-co
mm
un
ity
In t
his
, th
e m
ost
spec
ies-
poo
r su
b-co
m-
mu
nit
y, C
allu
na
is t
ypic
ally
dom
inan
tan
d a
bun
dan
t in
pio
nee
r an
d b
uil
din
gre
grow
th a
fter
bu
rnin
g. E
rica
cin
erea
is
very
fre
quen
t an
d c
an b
e p
rom
inen
t.V
acci
niu
m m
yrti
llu
s is
occ
asio
nal
an
dE
mp
etru
m n
igru
m n
igru
m a
nd
Eri
cate
tral
ix s
carc
e. M
onoc
otyl
edon
s ar
efe
w w
ith
Des
cham
psi
a fl
exu
osa
very
freq
uen
t an
d s
omet
imes
pro
min
ent.
Mol
inia
cae
rule
ais
pre
fere
nti
al a
nd
pat
chil
y ab
un
dan
t w
ith
occ
asio
nal
Sci
rpu
s ce
spit
osu
s an
d J
un
cus
squ
arro
-su
s. C
arex
bin
ervi
s is
wel
l re
pre
sen
ted
.A
par
t fr
om P
oten
till
a er
ecta
an
dG
aliu
m s
axat
ile,
dic
otyl
edon
s ar
e ve
ry s
par
se. T
he
grou
nd
lay
er i
s al
sop
oor
in s
pec
ies
and
of
low
cov
er.
Th
is s
ub-
com
mu
nit
y is
fou
nd
th
rou
gh-
out
the
ran
ge o
f H
10.
Em
pet
rum
nig
rum
ssp
. nig
rum
quit
e co
mm
on a
nd
Sci
rpu
sce
spit
osu
s p
atch
ily
pro
min
ent
wit
h f
requ
ent
Car
ex p
anic
eaan
d C
. pil
uli
fera
an
d o
ccas
ion
alH
up
erzi
a se
lago
. R
acom
itri
um
lan
ugi
nos
um
com
mon
an
dof
ten
abu
nd
ant
amon
g d
egen
er-
atin
g bu
shes
wit
h p
atch
es o
fC
lad
onia
un
cial
is a
nd
C
. im
pex
a.
Em
pet
rum
nig
rum
ssp
. nig
rum
and
Sci
rpu
s ce
spit
osu
s oc
ca-
sion
al a
t m
ost
and
Mol
inia
caer
ule
a ve
ry c
omm
on a
t lo
wco
vers
wit
h f
requ
ent
Car
ex
bin
ervi
s an
d o
ccas
ion
al J
un
cus
squ
arro
sus.
Cam
pyl
opu
s p
ara-
dox
us,
Sp
hag
nu
m c
apil
lifo
liu
man
d D
iplo
ph
yllu
m a
lbic
ans
occa
sion
al t
o fr
equ
ent.
H10
b
Ra
com
itri
um
la
nu
gin
osu
msu
b-co
mm
un
ity
Th
is i
s fo
un
d o
n e
xpos
ed s
ites
wh
ere
the
sub-
shru
b ca
nop
y is
mor
e op
enan
d C
allu
na
vulg
aris
is
the
usu
al
dom
inan
t. E
rica
cin
erea
is
freq
uen
t,V
acci
niu
m m
yrti
llu
s oc
casi
onal
an
d E
mp
etru
m n
igru
m s
pp
.nig
rum
is
pre
fere
nti
al a
nd
qu
ite
com
mon
.G
rass
es a
re s
par
se w
ith
sca
tter
ed t
uft
sof
Des
cham
psi
a fl
exu
osa
oth
er g
rass
esve
ry o
ccas
ion
al.
Car
ex b
iner
vis
is r
are,
its
pla
ce b
ein
g ta
ken
by
Car
ex p
ilu
lif-
era
and
C. p
anic
ea. S
cirp
us
cesp
itos
us
is a
lso
freq
uen
t.
Pot
enti
lla
erec
ta
is t
he
only
fre
quen
t d
icot
yled
onH
up
erzi
a se
lago
is
pre
fere
nti
ally
com
-m
on. T
her
e ar
e su
bsta
nti
al a
reas
of
the
grou
nd
lay
er w
ith
Rac
omit
riu
m l
anu
gi-
nos
um
th
e m
ost
abu
nd
ant
mos
s, a
nd
freq
uen
t H
ypn
um
cu
pre
ssif
orm
e s.
l.L
ich
ens
are
wel
l re
pre
sen
ted
.
Th
is s
ub-
com
mu
nit
y is
typ
ical
of
the
Wes
tern
Isl
es a
nd
Sh
etla
nd
.
96
Calluna vulgaris is the only constant sub-shrubfound in this community and is often abundant,although cover may be discontinuous and patchyin younger or grazed stands. Other frequent sub-shrubs are Erica cinerea and Empetrumnigrum ssp. nigrum, and each can be locally abundant, to the exclusion of Calluna itself.Sometimes Rosa pimpinellifolia is plentiful, andtogether with Erica tetralix and Salix repens isfound in transitions to wetter heath.
Carex arenaria is constant, but no more than moderately abundant and often senile, exceptwhere the sand is locally mobile. Ammophila arenaria is also frequent throughout, though usually sparse. In more species-poor stands thesemay be the only species, but often there is someFestuca rubra (or F. ovina) with Agrostis capillarisand Anthoxanthum odoratum and less commonlyPoa pratensis. Variation among dicotyledons ismodest, but Galium verum, Lotus corniculatus,Viola riviniana and Thymus praecox all occurquite frequently with several other herbs.
There may be hypnoid mosses such as Hypnumcupressiforme s.l., Pleurozium schreberi, Hylo-comium splendens and Rhytidiadelphus tri-quetrus in the turf. On areas of bare ground acro-carps such as Polytrichum juniperinum, P. pilifer-um and Ceratodon purpureus may be patchilyabundant.
This is the characteristic sub-shrub vegetationof stabilised, base-poor sands on dunes and plainsaround the coasts of Britain. The heath is largelyconfined to sands with a pH of less than 5 and canonly establish on sediments with surface stabilitysuch as found on older dunes and on consolidatedsand plains. It is very local along the coasts ofwestern England and Wales, becoming commonerin Scotland.
The community develops in primary successionby colonising fixed dune grasslands on acid sandsor where more lime-rich sands have becomeleached. Relief from grazing is probably importantfor its establishment but once established predationby herbivores, along with variation in regional cli-mate and substrate, influences its composition andstructure, and ultimately, grazing maintains thecommunity against reversion to grassland or pro-gression to scrub and woodland.
H11 Calluna vulgaris –Carex arenaria heath
97
H11
Eri
ca c
iner
ea c
onst
ant
and
Air
ap
raec
ox f
requ
ent
but
Em
pet
rum
nig
rum
nig
rum
,Agr
osti
s ca
pil
lari
san
d G
aliu
m s
axat
ile
are
rare
.D
icra
nu
m s
cop
ariu
m c
omm
on
and
som
e of
Cla
don
ia f
urc
ata,
C. f
loer
kian
a,C
. pyx
idat
a,C
. gra
cili
s an
d C
. fol
iace
a in
an
ofte
n e
xten
sive
car
pet
of
lich
ens.
H11
a
Eri
ca c
iner
ea s
ub-
com
mu
nit
y
Th
is s
ub-
com
mu
nit
y is
pro
min
ent
in s
outh
ern
are
as w
her
e ra
infa
ll i
sre
lati
vely
low
. Cal
lun
a vu
lgar
is a
nd
Eri
ca c
iner
ea a
re g
ener
ally
co-
dom
i-n
ant
wit
h E
rica
cin
erea
som
etim
esco
lon
isin
g fi
rst.
Ros
a p
imp
inel
lifo
lia
is a
dis
tin
ctiv
e in
vad
er. F
estu
caru
bra/
ovin
a is
ver
y co
mm
on w
ith
scat
tere
d s
hoo
ts o
f C
arex
are
nar
iaan
d L
uzu
la c
amp
estr
is. O
ther
her
bsar
e oc
casi
onal
. Th
e d
isti
nct
ive
elem
ent
is t
he
cryp
toga
ms,
oft
enoc
cup
yin
g th
e bu
lk o
f th
e gr
oun
d.
Hyp
noi
d m
osse
s ar
e sc
arce
an
d m
ost
obvi
ous
are
the
lich
ens,
par
ticu
larl
yC
lad
onia
sp
p.,
incl
ud
ing
thos
e li
sted
abov
e. C
orn
icu
lari
a ac
ule
ata
and
Hyp
ogym
nia
ph
ysod
es a
re a
lso
com
-m
on, s
omet
imes
wit
h P
elti
gera
can
i-n
a an
d l
ow-g
row
ing
Usn
ea s
pec
ies.
Th
is i
s th
e m
ost
wid
esp
read
su
b-co
mm
un
ity
but
it i
s re
pla
ced
loc
al-
ly b
y th
e E
mp
etru
msu
b-co
mm
un
ity
in n
orth
an
d e
ast
Sco
tlan
d.
Eri
ca c
iner
ea a
nd
Air
a p
raec
ox o
nly
occa
sion
al a
t m
ost,
bu
t E
mp
etru
mn
igru
m n
igru
m,A
gros
tis
cap
illa
ris
and
Gal
ium
sax
atil
e ve
ry f
requ
ent.
Cla
don
ia a
rbu
scu
la a
nd
C. i
mp
exa
can
be
pat
chil
y p
rom
inen
t bu
tst
retc
hes
of
lich
en-r
ich
tu
rf a
re
not
ch
arac
teri
stic
.
H11
b
Em
pet
rum
nig
rum
ssp
. nig
rum
sub-
com
mu
nit
y
Cal
lun
a vu
lgar
is a
nd
Em
pet
rum
nig
rum
,wh
ich
for
ms
larg
e p
atch
es,
are
the
co-d
omin
ants
her
e, e
spec
ial-
ly i
n t
he
cool
er w
ette
r n
orth
of
Bri
tain
. Fes
tuca
ru
bra/
ovin
are
mai
ns
com
mon
am
ong
freq
uen
tC
arex
are
nar
ia a
nd
Lu
zula
cam
pes
tris
wit
h o
ther
sp
ecie
s as
list
ed a
bove
. Hyp
noi
d m
osse
s ar
em
ore
pro
min
ent
wit
h H
ypn
um
cup
ress
ifor
me,
Ple
uro
ziu
m s
chre
-be
ri,R
hyt
idia
del
ph
us
triq
uet
rus
and
Hyl
ocom
ium
sp
len
den
s an
dle
ss c
omm
only
Pti
lid
ium
cil
iare
.L
ich
ens
are
mor
e p
atch
y.
Th
is s
ub-
com
mu
nit
y is
fou
nd
loc
al-
ly i
n n
orth
an
d e
ast
Sco
tlan
d.
Th
e as
soci
ates
lis
ted
op
pos
ite
are
all
scar
ce i
n i
mp
over
ish
ed m
ixtu
res
of C
allu
na
vulg
aris
an
d C
arex
ar
enar
ia.
H11
c
Sp
ecie
s-p
oor
sub-
com
mu
nit
y
Cal
lun
a vu
lgar
is i
s ov
erw
hel
min
gly
dom
inan
t w
ith
on
ly o
ccas
ion
al o
rev
en n
o bu
shes
of
oth
er s
pec
ies.
Car
ex a
ren
aria
rem
ain
s co
nst
ant
but
gras
ses
may
on
ly b
e re
pre
sen
ted
by a
few
tu
fts
of A
nth
oxan
thu
mod
orat
um
or
Des
cham
psi
a fl
exu
osa.
Oth
er h
erbs
are
als
osp
arse
. Bry
oph
ytes
may
in
clu
de
hyp
noi
d s
pec
ies
and
Dic
ran
um
sc
opar
ium
.
Th
is s
ub-
com
mu
nit
y ca
n b
e fo
un
dth
rou
ghou
t th
e ra
nge
of
H11
.
98
This heath is generally dominated by Calluna vulgaris and includes most of the Calluneta fromless oceanic sub-montane areas where burning iscommonly practised, including many grousemoors. Here a predominance of building-phaseCalluna is found, but a more open cover of degen-erate Calluna can often also be present. Vacciniummyrtillus is constant though it is usually subordi-nate to Calluna and is most vigorous out of reachof grazing animals. Vaccinium vitis-idaea is alsofound, sometimes with local prominence, andErica cinerea may also be present on drier slopes.Empetrum nigrum ssp. nigrum is frequent, form-ing mats after burning, but then becomes reducedafter the Calluna has regrown.
In many stands herbs are rare. OnlyDeschampsia flexuosa is frequent throughout.When grazing is regular there may be additionalherbs including Festuca ovina, Agrostis capillaris,A. canina, Nardus stricta, Potentilla erecta and Galium saxatile.
The ground-layer is often prominent withbulky mosses characteristic, such as Dicranum scoparium, Pleurozium schreberi, Hypnumcupressiforme s.l. and Hylocomium splendens,together with larger Cladonia species. Encrusting
lichens and Polytrichum species can be abundantin the years following burning.
This community is the typical sub-shrub community of acidic to circumneutral, free-drainingmineral soils throughout the cold and wet sub-mon-tane zone generally between 200 m and 600 m. Thesoils on which it occurs are widespread throughoutthis zone, developing from a variety of siliceous par-ent materials, intrusive igneous rock or coarse glacio-fluvial gravels. Despite being free-draining the soilsare normally moist for the majority of the yearbecause of the climate and the superficial pH is usu-ally between 3.5 and 4.5. It is extensive in the east-central Highlands but also important in south-eastScotland, the Lake District, parts of Wales and theSouth-West Peninsula and the North York Moors. Inplaces like the southern Pennines, where air pollu-tion is severe, it is largely replaced by Calluna vul-garis – Deschampsia flexuosa heath (H9).
Burning and grazing are the major influenceson floristics and structure, although climatic andedaphic difference play some part in determiningvariation within the community. Successionaldevelopments are usually held in check by burning and grazing and without these moststands would probably progress to scrub andwoodland. Continuous heavy grazing favours theloss of sub-shrub vegetation to grassland and insome instances, particularly after burning, mayresult in the spread of Pteridium aquilinum.
H12 Calluna vulgaris –Vaccinium myrtillus heath
99
H12
Vac
cin
ium
vit
is-i
dae
a an
d E
mp
etru
mn
igru
m n
igru
m f
requ
ent,
wit
h o
ccas
ion
alJu
ncu
s sq
uar
rosu
s an
d B
lech
nu
m s
pic
ant.
H12
b
Vac
cini
um v
itis
-ida
ea–
Cla
doni
aim
pexa
sub-
com
mun
ity
Th
is i
ncl
ud
es m
ost
of t
he
rich
er s
tan
ds
of t
his
hea
th, w
hic
h d
evel
op a
nu
mbe
rof
yea
rs a
fter
bu
rnin
g.
Alt
hou
ghC
allu
na
vulg
aris
is s
till
th
e ge
ner
ald
omin
ant
it i
s fr
equ
entl
y ac
com
pan
ied
by V
acci
niu
m m
yrti
llu
s,V.
vit
is-i
dae
aan
d E
mp
etru
m n
igru
m n
igru
m a
nd
occa
sion
ally
wit
h E
rica
cin
erea
. Her
bsar
e ge
ner
ally
sp
arse
wit
h o
nly
sca
t-te
red
pla
nts
of
Des
cham
psi
a fl
exu
osa,
and
occ
asio
nal
Pot
enti
lla
erec
ta,
Jun
cus
squ
arro
sus
and
Ble
chn
um
sp
i-ca
nt.
Bry
oph
ytes
an
d l
ich
ens
are
mor
en
um
erou
s in
clu
din
g th
e sp
ecie
s li
sted
abov
e.
Su
b-sh
rub
cove
r ex
ten
sive
an
d v
arie
dw
ith
Vac
cin
ium
vit
is-i
dae
a es
pec
iall
yfr
equ
ent
and
sp
ecie
s li
sted
op
pos
ite
typ
ical
ly s
carc
e.
Cry
pto
gam
flo
ra v
ar-
ied
an
d o
ften
abu
nd
ant,
wit
h b
ulk
yp
leu
roca
rps
pro
min
ent,
Hyl
ocom
ium
sple
nd
ens
ofte
n jo
inin
g P
leu
rozi
um
sch
rebe
ri a
nd
Hyp
nu
m ju
tlan
dic
um
.C
lad
onia
im
pex
a,C
. un
cial
is a
nd
C.
pyx
idat
a co
mm
on.
H12
c
Ga
liu
m s
axa
tile
– F
estu
ca o
vin
asu
b-co
mm
un
ity
Th
is s
ub-
com
mu
nit
y is
fou
nd
on
bet
ter
soil
s an
d a
fter
bu
rnin
g, o
ften
fol
low
edby
gra
zin
g. C
allu
na
vulg
aris
is
less
dom
inan
t an
d w
ith
oth
er s
ub-
shru
bsfo
rms
an o
pen
gro
wth
wit
hin
a g
rass
ysw
ard
. Des
cham
psi
a fl
exu
osa
is jo
ined
by a
var
iety
of
her
bs i
ncl
ud
ing
thos
eli
sted
abo
ve. W
her
e th
e so
ils
are
less
base
-poo
r, s
pec
ies
such
as
Lotu
s co
rnic
ula
tus,
Lath
yru
s m
onta
nu
s,S
ucc
isa
pra
ten
sis,
Vio
la r
ivin
ian
a an
dA
nem
one
nem
oros
a ca
n b
e lo
call
yab
un
dan
t. B
ryop
hyt
es r
emai
n q
uit
eva
ried
, bu
t li
chen
s ar
e fe
w a
nd
of
low
cove
r.
Vac
cin
ium
vit
is-i
dae
a an
d E
mp
etru
mn
igru
m n
igru
m b
oth
sca
rce
in r
ath
ersp
ecie
s-p
oor
hea
th, u
sual
ly o
ver-
wh
elm
ingl
y d
omin
ated
by
Cal
lun
avu
lgar
is.
H12
a
Ca
llu
na
vu
lga
ris
sub-
com
mu
nit
y
Veg
etat
ion
is
typ
ical
ly s
pec
ies-
poo
rw
ith
Cal
lun
a vu
lgar
isov
erw
hel
min
gly
dom
inan
t an
d o
ther
su
b-sh
rubs
of
low
cove
r. V
acci
niu
m m
yrti
llu
s is
ver
y fr
equ
ent
and
Eri
ca c
iner
ea c
omm
on,
but
both
on
ly a
s sc
atte
red
sh
oots
.
Oth
er v
ascu
lar
asso
ciat
es a
re f
ew.
Des
cham
psi
a fl
exu
osa
is f
requ
ent
assc
atte
red
sh
oots
an
d s
par
se p
lan
ts o
fP
oten
till
a er
ecta
and
Pte
rid
ium
aqu
il-
inu
m a
re q
uit
e co
mm
on. T
he
grou
nd
cove
r is
not
ext
ensi
ve a
nd
on
lyD
icra
nu
m s
cop
ariu
m,H
ypn
um
jut-
lan
dic
um
an
d P
leu
rozi
um
sch
rebe
rioc
cur
freq
uen
tly
as s
catt
ered
sh
oots
.
Cal
lun
a vu
lgar
is n
ot s
o ab
un
dan
t as
usu
al, a
nd
oth
er s
ub-
shru
bs o
f ge
ner
ally
mod
erat
e co
ver
in a
gra
ssy
hea
th, w
ith
freq
uen
t F
estu
ca o
vin
a,A
gros
tis
cap
il-
lari
s,N
ard
us
stri
cta,
Gal
ium
sax
atil
ean
d P
oten
till
a er
ecta
an
d o
ccas
ion
alC
arex
pil
uli
fera
,Cam
pan
ula
rot
un
dif
o-li
a an
d P
olyg
ala
serp
ylli
foli
a. L
ich
ens
not
ext
ensi
ve, o
ften
pat
chy.
100
This heath has a dwarfed mat of sub-shrubs withfew vascular associates, but with a prominentlichen flora. Calluna vulgaris is the most frequentspecies, generally prostrate and forming a carpetor in wave-like bands or on solifluction terraces.Among other sub-shrubs Empetrum nigrum ismost important, usually as ssp. hermaphroditum,but with ssp. nigrum at lower altitudes. It may beintermixed in the mat or forming clumps.Loiseleuria procumbens is quite frequent andabundant, but Arctostaphylos uva-ursi is at mostoccasional. Both Vaccinium myrtillus and V. vitis-idaea are common, but always subordinatein cover.
The other vascular associates are few andsparse. Deschampsia flexuosa and Carex bigelowiiare most frequent with species such as Scirpus cespitosus, Agrostis canina and Molinia caeruleaat lower altitudes and Juncus trifidus becomingoccasional at higher levels. Huperzia selago is alsofrequent in higher altitude stands.
Lichens are important structurally. Cladoniaarbuscula is especially common and, where thereis some shelter, may be abundant. It is usuallymixed with C. rangiferina which locally may beco-dominant. Also constant are C. uncialis,Cetraria islandica, Alectoria nigricans and
Cornicularia aculeata. Among these, bryophytesare generally few and rarely of any abundance.Racomitrium lanuginosum is constant and canform locally conspicuous patches.
This heath is the characteristic sub-shrub vegetation of base-poor soils, over exposed ridgesand summits of mountains, in parts of Britain witha cold continental climate. It is found on soilswith a superficial pH of between 4 and 5, and frequently a humic surface above pervious acidicbedrocks and superficials. It is most widespreadthrough the east-central Highlands of Scotland,thinning out westwards into the central Grampiansand north-west Highlands where it is progressive-ly replaced by its oceanic counterpart Calluna vul-garis – Racomitrium lanuginosum heath (H14).There are a few fragmentary localities in northernEngland and Wales.
It is a vegetation type of unsheltered slopes generally between 600 m and 900 m where thereare almost constant strong winds which frequent-ly clear the ground of snow and subject the vege-tation not only to reduced precipitation but also tothe effects of frequent and severe frosts and subse-quent thaws. Burning and grazing may have cur-tailed its range in suitable localities in the moresoutherly uplands, but in the eastern Highlandsthe vegetation seems to be largely unaffected by treatments and the community can be considereda climax.
H13 Calluna vulgaris – Cladoniaarbuscula heath
101
H13
Vaccinium species common andLoiseleuria procumbens frequent in anearly prostrate mat, with Cladoniacrispata, C. coccifera, Ochrolechiafrigida and Thamnolia vermicularisoften found.
H13a
Cladonia arbuscula – Cladoniarangiferina sub-community
This sub-community is found atlower altitudes or more shel-tered sites where larger Cladoniaspecies, as above, are especiallyabundant, often exceeding thesub-shrubs in cover. Cladoniaimpexa can also be found, but C. gracilis and C. crispata arescarce. The most common sub-shrub is Calluna vulgaris butEmpetrum nigrum is very common, often as ssp.nigrum. Vaccinium species areonly occasional.
Deschampsia flexuosa onlyoccasional and Carex bigelowiiscarce but Erica cinerea and E.tetralix occasional among thesub-shrubs, sometimes with Scirpus cespitosus andMolinia caerulea. Cetrarianivalis and Cladonia gracilisuncommon, but C. arbusculaand C. rangiferina especiallyabundant.
H13b
Empetrum nigrum ssp. hermaphroditum – Cetrarianivalis sub-community
On bleak exposed sites at higheraltitudes lichens remain abun-dant, but Calluna vulgaris or occa-sionally Empetrum nigrum her-maphroditum is dominant. BothVaccinium myrtillus and V. vitis-idaea are more frequent than inH13a but usually have low cover.Loiseleuria procumbens is occa-sional. Cladonia arbuscula is stillthe most frequent lichen but iscommonly joined by the specieslisted above. Mosses only make aminor contribution and the fewvascular associates are present asscattered individuals.
Vaccinium species less fre-quent and Loiseleuriaprocumbens and listedlichens occasional at most.
H13c
Cladonia crispata – Loiseleuriaprocumbens sub-community
Calluna vulgaris is again the usualdominant, but one or both subspeciesof Empetrum nigrum are common andcan be abundant. In the flattened sub-shrub mat there is a mixed carpet oflichens including the species listedabove. The herbs comprise scatteredshoots of Carex bigelowii, Huperziaselago and Deschampsia flexuosa.
Deschampsia flexuosa very com-mon with occasional Diphasiumalpinum and Juncus trifidus.Cetraria nivalis frequent andCladonia gracilis and C. bellidiflora occasional.
102
This heath consists essentially of a dwarfed sub-shrub mat with Calluna vulgaris usually predominant, together with Racomitrium lanugi-nosum. Other sub-shrubs play a subordinate role,but may be common. Most frequent is Empetrumnigrum, with the two subspecies characterisingopposite ends of the altitudinal range (ssp. nigrumpreferentially common towards lower levels andssp. hermaphroditum largely confined to higher altitudes). Erica cinerea is also frequent.
Other vascular associates are few and usually scattered. Deschampsia flexuosa, Huperzia selago, Carex pilulifera, Potentilla erecta andScirpus cespitosus are all frequent, and Carexbigelowii becomes common at higher altitudes.
The extensive woolly carpet of Racomitriumlanuginosum which can be up to 5-10 cm thick isthe most noticeable feature of this community.Hypnum cupressiforme s.l. is also very frequent insome stands, often with several other mosses andoccasional hepatics. Lichens are common and var-ied but not abundant, and species like Cetrarianivalis and Alectoria ochroleuca are absent.Cladonia arbuscula and C. uncialis are the mostfrequent, and Sphaerophorus globosus andCornicularia aculeata are also common through-
out. Cladonia impexa is frequent at lower alti-tudes and Cladonia gracilis, C. bellidiflora,Cetraria islandica and Ochrolechia frigida occuroften at higher altitudes.
This community is the typical sub-shrub community of base-poor soils on windsweptplateaux and ridges at moderate to fairly high altitudes in the cool oceanic climate of the moun-tains of north-west Scotland. It can be found up to750 m, although this can extend up to 1000 m inthe east; to the west and north, on islands likeSkye, Orkney and Shetland, it can extend down tobelow 250 m. The community is found on thebase-poor rankers and podzolic soils which arewidespread in this region, with a superficial pHbetween 4 and 5 and a humic surface. It is verymuch a community of the north-west Highlandswith scattered occurrences in the centralGrampians.
Like its eastern counterpart Calluna vulgaris –Cladonia arbuscula heath (H13) it is found overgentle to moderately steep slopes which areexposed to fairly constant strong winds that clearthe snow which might otherwise provide shelterin the coldest months. Although it is sometimesgrazed by sheep and deer, it is unlikely that thisfactor is important in maintaining the characteris-tic composition and physiognomy, and this vege-tation can be regarded as the natural climax insuch exposed situations in its range.
H14 Calluna vulgaris –Racomitrium lanuginosum heath
103
H14
Arc
tost
aph
ylos
uva
-urs
i co
nst
ant
wit
hfr
equ
ent
A. a
lpin
us,
Em
pet
rum
nig
rum
nig
rum
an
d E
rica
cin
erea
. Sci
rpu
sce
spit
osu
s co
mm
on w
ith
Mol
inia
caer
ule
a an
d C
arex
bin
ervi
s oc
casi
onal
. Dic
ran
um
sco
par
ium
,D
iplo
ph
yllu
m a
lbic
ans
and
Ple
uro
ziu
m s
chre
beri
fre
quen
t.
H14
a
Fes
tuca
ovi
na
sub-
com
mu
nit
y
Cal
lun
a vu
lgar
is o
r R
acom
itri
um
lan
ugi
nos
um
or
mix
ture
s of
th
e tw
od
omin
ate
the
vege
tati
on m
at w
ith
oth
er s
pec
ies
pla
yin
g on
ly a
min
orro
le. E
mp
etru
m n
igru
m s
sp. n
igru
man
d h
erm
aph
rod
itu
m a
nd
Eri
caci
ner
ea a
re o
nly
occ
asio
nal
an
d i
nso
me
stan
ds
Lois
eleu
ria
pro
cum
ben
sca
n b
e p
rom
inen
t. M
ore
stri
kin
g is
th
e va
riet
y of
her
bace
ous
asso
ciat
es.
Des
cham
psi
a fl
exu
osa
is l
ess
com
mon
than
usu
al, b
ut
Car
ex b
igel
owii
is
fre-
quen
t w
ith
C. p
ilu
life
ra,H
up
erzi
a se
la-
go a
nd
Pot
enti
lla
erec
ta. M
ore
pre
fer-
enti
al a
re t
he
spec
ies
list
ed a
bove
.L
ich
en c
over
is
com
par
ativ
ely
low
bu
t C
lad
onia
un
cial
is i
s ve
ry c
omm
on.
Th
is a
nd
th
e A
rcto
stap
hyl
os s
ub-
com
-m
un
ity
are
fou
nd
at
the
low
est
alti
-tu
des
an
d m
ost
shel
tere
d s
ites
occ
u-
pie
d b
y th
e co
mm
un
ity.
Em
pet
rum
nig
rum
her
map
hro
dit
um
and
her
bs a
nd
lic
hen
s li
sted
op
pos
ite
occa
sion
al a
t m
ost.
Fes
tuca
ovi
na
and
Agr
osti
s ca
nin
a ve
ry c
omm
on, s
ome-
tim
es w
ith
An
ten
nar
ia d
ioic
a,C
arex
pan
icea
,Th
ymu
s p
raec
ox a
nd
Eu
ph
rasi
a m
icra
nth
a.
H14
b
Em
pet
rum
nig
rum
ssp
. h
erm
ap
hro
dit
um
sub-
com
mu
nit
y
Cal
lun
a vu
lgar
is g
ener
ally
abu
nd
ant
wit
h R
acom
itri
um
lan
ugi
nos
um
som
e-ti
mes
co-
dom
inan
t bu
t of
ten
su
bord
i-n
ate.
Th
e va
riet
y of
her
bs c
har
acte
ris-
tic
of H
14a
is n
ot f
oun
d a
lth
ough
Des
cham
psi
a fl
exu
osa
and
Car
exbi
gelo
wii
are
ver
y fr
equ
ent
and
Pot
enti
lla
erec
ta,H
up
erzi
a se
lago
an
d C
arex
pil
uli
fera
rem
ain
com
mon
.M
ost
dis
tin
ctiv
e ar
e th
e cr
ypto
gam
sw
ith
sev
eral
ple
uro
carp
ous
mos
ses
and
th
e ty
pic
al l
ich
en f
lora
of
the
com
mu
nit
y w
ith
ad
dit
ion
al s
pec
ies,
incl
ud
ing
thos
e li
sted
abo
ve.
Th
is i
s th
e ty
pic
al f
orm
of
this
su
b-co
mm
un
ity
and
is
fou
nd
at
the
hig
hes
tal
titu
des
of
the
ran
ge o
f H
14.
Em
pet
rum
nig
rum
nig
rum
an
d
Eri
ca c
iner
ea a
t m
ost
occa
sion
al.
Arc
tost
aph
ylos
sp
ecie
s an
d t
he
her
bsan
d b
ryop
hyt
es l
iste
d o
pp
osit
e ve
rysc
arce
.
H14
c
Arc
tost
ap
hyl
os u
va-u
rsi
sub-
com
mu
nit
y
Cal
lun
a vu
lgar
is a
nd
Rac
omit
riu
mla
nu
gin
osu
m r
etai
n t
he
rep
rese
nta
tion
of H
14b
but
the
sub-
shru
bs a
re
mor
e va
ried
wit
h E
rica
cin
erea
an
dE
mp
etru
m n
igru
m s
sp. n
igru
m a
t th
eir
pea
k of
fre
quen
cy, a
nd
loc
ally
abu
nd
ant
Arc
tost
aph
ylos
uva
-urs
i an
d
A. a
lpin
us.
Am
ong
the
vasc
ula
r as
soci
-at
es C
arex
big
elow
ii i
s ve
ry s
carc
e. I
nth
e br
yop
hyt
e m
at D
icra
nu
m s
cop
ari-
um
an
d l
arge
r p
leu
roca
rps
such
as
Hyp
nu
m c
up
ress
ifor
me
s.l.
an
dP
leu
rozi
um
sch
rebe
ri m
ake
thei
rbi
gges
t co
ntr
ibu
tion
. In
th
e li
chen
flo
raC
lad
onia
im
pex
a is
com
mon
tog
eth
erw
ith
th
e co
mm
un
ity
spec
ies.
Th
is a
nd
th
e F
estu
ca s
ub-
com
mu
nit
yar
e fo
un
d a
t th
e lo
wes
t al
titu
des
an
dm
ost
shel
tere
d s
ites
occ
up
ied
by
the
com
mu
nit
y.
Em
pet
rum
nig
rum
her
map
hro
dit
um
con
stan
t w
ith
fre
quen
t N
ard
us
stri
cta
and
Dip
has
ium
alp
inu
m a
nd
som
e-ti
mes
wit
h a
n e
xten
sive
lic
hen
cov
er,
incl
ud
ing
Cet
rari
a is
lan
dic
a,C
lad
onia
grac
ilis
an
d O
chro
lech
ia f
rigi
da.
104
Prostrate juniper, referable to Juniperus communisssp. nana, is occasional in a wide variety of sub-shrub heaths. Here, however, it is consistentlydominant in the sub-shrub mat, accompanied by asmall but distinctive group of oceanic hepatics.The mat is generally less than 10 cm high, fairlycontinuous in the best stands, but it may form amosaic with islands of vegetation on tracts of barerock and debris. Several other sub-shrubs are wellrepresented: Calluna vulgaris and Erica cinereaare especially frequent and the former often fairlyabundant. Arctostaphylos uva-ursi and A. alpinusare less common, and Empetrum nigrum ssp. her-maphroditum is occasional.
Vascular associates are typically few and are usually scattered in the mat. Deschampsia flexuosa,Scirpus cespitosus and Potentilla erecta are constant,with Huperzia selago, Solidago virgaurea, Dactyl-orhiza maculata, Polygala serpyllifolia, Succisapratensis, and Antennaria dioica more occasional.
In some stands the cryptogam flora is similar toother kinds of dwarfed sub-shrub heath. In typicalexamples of this community, however, the speciesRacomitrium lanuginosum, Cladonia uncialis, C. imp-exa, Sphaerophorus globosus and Corniculariaaculeata, which are common in all these otherkinds of heath, are joined by Pleurozia purpurea,Frullania tamarisci and Diplophyllum albicans whichare not. Where the sub-shrub canopy is well-devel-oped the total cover of the cryptogams is much lessthan in the typical moss-heaths of the region.
This heath is confined to humic rankers at moderate altitudes in the cool oceanic climatealong the western seaboard of the north-westHighlands and some of the Western Isles. Soildevelopment under this community is typicallyrudimentary with just shallow accumulations ofdecaying juniper and bryophyte litter on Cambrianquartzite screes. Although perhaps once morewidespread throughout the north-west Highlands,the community is now of rather patchy occurrencealong the western side of the more northerly moun-tains with especially good stands on Beinn Eigheand Foinaven. The community is replaced in thecontinental climate of the east-central Highlands bythe Juniperus communis ssp. communis – Oxalisacetosella woodland (W19).
It is confined to the lower portion of the altitu-dinal ranges of the other dwarf sub-shrub heathsand, although the vegetation mat is typically blownclear of snow, is not usually found in the kind ofseverely exposed situations of which the othercommunities are so characteristic. This communi-ty is given some protection against the effects ofgrazing by the rocky ground on which it is typical-ly found, but it is readily damaged by burning.
No sub-communities.
H15 Calluna vulgaris – Juniperuscommunis ssp. nana heath
Although Arctostaphylos uva-ursi is found as anoccasional in a variety of heath types, it is mostoften found in this community, which has a dis-tinct boreal character. Calluna vulgaris is alwayspresent and is the most usual dominant, forming acanopy 20-40 cm high and having a substantialtotal cover. Arctostaphylos uva-ursi is constantand can become modestly abundant in gaps with-in the heather cover. Erica cinerea is also verycommon but of low cover. In many stands there issome Vaccinium myrtillus and V. vitis-idaea.
Quite commonly there are small amounts ofGenista anglica, but herbaceous associates are fewexcept in the Pyrola media – Lathyrus montanussub-community. The only constant grass isDeschampsia flexuosa and this can be joined byLuzula multiflora and L. pilosa.
Bryophytes are variable, with the bulkier moss-es often strongly associated with particular stagesin the heather regeneration cycle. Hypnum jutlandicum, Pleurozium schreberi and Dicranumscoparium, however, are very common overall andHylocomium splendens is also a constant throughmuch of the community.
Lichens also differ in their representation, withonly Cladonia impexa constant and, in manystands, of low cover. Fruticose species such as C. arbuscula and C. rangiferina tend to follow thelarger pleurocarps in developing among the moreshady and humid conditions of older heathercanopies. Hypogymnia physodes and, less com-monly, Cetraria glauca can be seen on decayingwoody stems.
This heath is characteristic of base-poor to cir-cumneutral soils at moderate altitudes, generallybetween 250 m and 600 m altitude, in the coldcontinental climate of the east-central Highlandsof Scotland. It is found on a variety of acid soils developed from lime-poor parent material. Itoccurs widely but fairly locally through the east-central Highlands with especially good representation in Speyside.
The community forms an important part of grouse-moor in the central Highlands and althoughedaphic differences play some part in determiningfloristic variation in the community, their effectsare often overlain and modified by the influenceof burning which ultimately maintains this vege-tation as a plagioclimax. Stretches of moorlandincluding stands of the community are often opento livestock but there is little information on theimpact of grazing on this vegetation.
H16 Calluna vulgaris –Arctostaphylos uva-ursi heath
105
H16
Arc
tost
aph
ylos
uva
-urs
i of
ten
ext
en-
sive
wit
h C
allu
na
vulg
aris
,Eri
caci
ner
ea a
nd
Vac
cin
ium
sp
ecie
s.F
estu
ca o
vin
a co
mm
on w
ith
oc
casi
onal
Agr
osti
s ca
pil
lari
s an
dA
nth
oxan
thu
m o
dor
atu
m. T
he
rich
her
b fl
ora
incl
ud
es f
requ
ent
Pot
enti
lla
erec
ta,P
yrol
a m
edia
,Vio
la r
ivin
ian
a,La
thyr
us
mon
tan
us,
Hyp
eric
um
pu
l-ch
rum
,An
emon
e n
emor
osa,
Trie
nta
lis
euro
pae
a,G
aliu
m s
axat
ile
and
Lot
us
corn
icu
latu
s.
H16
c
Cla
don
iasp
p. s
ub-
com
mu
nit
y
Alt
hou
gh A
rcto
stap
hyl
os u
va-u
rsi
isso
met
imes
qu
ite
abu
nd
ant,
Cal
lun
avu
lgar
isis
mor
e of
ten
ove
rwh
elm
ingl
yd
omin
ant.
Bot
h E
rica
cin
erea
an
dG
enis
ta a
ngl
ica
occu
r fr
equ
entl
y.
T
he
her
bs o
f su
b-co
mm
un
ity
H16
a ar
e h
ard
ly e
ver
fou
nd
. Am
ong
the
bryo
ph
ytes
th
e ch
arac
teri
stic
mos
ses
Hyl
ocom
ium
sp
len
den
s an
dP
leu
rozi
um
sch
rebe
ri a
re v
ery
pat
chy,
bu
t H
ypn
um
jutl
and
icu
m a
nd
Dic
ran
um
sco
par
ium
rem
ain
fre
quen
tof
ten
wit
h a
lit
tle
Poh
lia
nu
tan
s. P
eat-
encr
ust
ing
lich
ens
are
mos
t n
otic
eabl
e,p
arti
cula
rly
the
Cla
don
ia s
pec
ies
list
ed a
bove
.
Vac
cin
ium
myr
till
us
abse
nt,
V. v
itis
-id
aea
and
Em
pet
rum
nig
rum
nig
rum
scar
ce, a
nd
hyp
noi
d m
osse
s p
atch
y.S
cirp
us
cesp
itos
us
and
Car
ex p
ilu
life
raco
mm
on a
nd
lic
hen
s ex
ten
sive
on
area
s of
bar
e gr
oun
d w
ith
fre
quen
tC
lad
onia
un
cial
is,C
. im
pex
a,C
. flo
-er
kean
a,C
. coc
cife
ra a
nd
C. s
quam
osa.
H16
b
Va
ccin
ium
myr
till
us
– V
acc
iniu
mvi
tis-
ida
easu
b-co
mm
un
ity
Arc
tost
aph
ylos
uva
-urs
i re
mai
ns
con
-st
ant
her
e bu
t C
allu
na
vulg
aris
is
usu
-al
ly d
omin
ant
and
wit
h t
he
sub-
shru
bsm
enti
oned
abo
ve. I
n c
ontr
ast
wit
hH
16a,
her
bs a
re s
carc
e th
ough
Fes
tuca
ovin
a,C
arex
pil
uli
fera
,Pot
enti
lla
erec
ta,L
uzu
la m
ult
iflo
ra,L
. pil
osa
and
Lis
tera
cor
dat
a ar
e oc
casi
onal
.C
ryp
toga
ms,
how
ever
are
mor
e d
iver
se a
nd
ext
ensi
ve w
ith
th
e bu
lky
ple
uro
carp
s H
ypn
um
jutl
and
icu
m,
Ple
uro
ziu
m s
chre
beri
an
d H
yloc
omiu
msp
len
den
s of
ten
abu
nd
ant.
Lar
ger
lich
ens
are
also
mor
e ap
par
ent
incl
ud
ing
seve
ral
Cla
don
ia s
pec
ies.
Cal
lun
a vu
lgar
is u
sual
ly a
str
ong
dom
i-n
ant
wit
h A
rcto
stap
hyl
os u
va-u
rsi
subo
r-d
inat
e an
d a
ssoc
iate
s li
sted
op
pos
ite
occa
sion
al a
t m
ost.
H16
a
Pyr
ola
med
ia–
La
thyr
us
mon
tan
us
sub-
com
mu
nit
y
Arc
tost
aph
ylos
uva
-urs
i is
mos
t p
rom
i-n
ent
in t
his
su
b-co
mm
un
ity,
on
les
sac
idic
bro
wn
ear
th s
oils
, for
min
g a
pat
chw
ork
wit
h C
allu
na
vulg
aris
.E
rica
cin
erea
can
hav
e a
hig
h c
over
and
th
e tw
o V
acci
niu
m s
pec
ies
are
com
mon
. Gen
ista
an
glic
a is
fai
rly
freq
uen
t. T
he
mos
t st
riki
ng
feat
ure
is
the
asso
ciat
ed h
erb
flor
a d
evel
oped
in
mor
e m
esot
rop
hic
con
dit
ion
s.G
rass
es a
re m
ore
com
mon
wit
hF
estu
ca o
vin
a fr
equ
entl
y jo
inin
gD
esch
amp
sia
flex
uos
a to
geth
er w
ith
the
her
bs l
iste
d a
bove
. Th
e m
osse
sch
arac
teri
stic
of
H16
are
com
mon
, bu
tno
t ab
unda
nt, i
nclu
ding
the
pre
fere
ntia
lR
hyt
idia
del
ph
us
triq
uet
rus.
Vac
cin
ium
myr
till
us
com
mon
lyac
com
pan
ies
V. v
itis
-id
aea
in a
sp
arse
un
der
stor
ey w
ith
Em
pet
rum
nig
rum
nig
rum
in
term
ingl
ed. H
ypn
oid
mos
ses
ofte
n e
xten
sive
wit
h C
lad
onia
arb
us-
cula
an
d C
. ran
gife
rin
aal
so f
requ
ent.
106
Arctostaphylos alpinus occurs with some frequency in various kinds of dwarfed sub-shrubheath, but is most typical of this communitywhere it is a constant, although usually a subordi-nate one, in the woody mat which is normally lessthan 10 cm tall. It is usually dominated by stuntedbushes of Calluna vulgaris with stretches of barestones between. Empetrum nigrum ssp. hermaph-roditum is strongly preferential to higher altitudesand ssp. nigrum is largely confined to lower situa-tions. Loiseleuria procumbens is characteristicallyfound with E. nigrum ssp. hermaphroditum, andErica cinerea with E. nigrum ssp. nigrum.Vaccinium myrtillus is common throughout butother Vaccinium species are scarce.
There are few herbs. Huperzia selago is the commonest and a constant, and is often accompa-nied, at higher altitudes, by Diphasium alpinum,Carex bigelowii and Antennaria dioica. Desch-ampsia flexuosa is also frequent throughout,though more so at lower altitudes where Potentillaerecta, Scirpus cespitosus and Carex piluliferaoccur most commonly.
More conspicuous are the lichens which form apatchy mosaic. Cladonia arbuscula and C. unc-ialis are constant. Preferential to higher altitudesare Cetraria glauca, C. islandica, Cornicularia
aculeata, Alectoria nigricans and Sphaerophorusglobosus. Mosses are not abundant. Racomitriumlanuginosum is constant, though in smallamounts, and Hypnum jutlandicum becomes frequent at lower altitudes.
This heath is the typical climax sub-shrub vegetation of rather base-poor moder soils oververy exposed ridges and crests at moderate to fairly high altitudes in the cold and humid climateof the mountains of north-west Scotland. It isfound at higher altitudes than the Calluna vulgaris – Racomitrium lanuginosum heath (H14)which has a similar distribution, and its normalrange is between 500 m and 750 m, although it canexceptionally be found up to 900 m, and down to250 m along the north Scottish coast and onOrkney. It is typically found on humic poorrankers and more occasionally mature podzolisedsoil that have been derived from a variety of lime-poor parent materials. This community isconfined to the north-west Highlands, the northScottish coast and Orkney.
The community may be lightly grazed by sheep and deer but this probably has little effecton its floristics or physiognomy. The inhospitableenvironment and the harsh conditions maintainthe vegetation as a climax. Burning is very delete-rious and may cause damage from which recoveryis extremely slow if not impossible. Burning mayhave eliminated this community from many sitesthroughout its range.
H17 Calluna vulgaris –Arctostaphylos alpinus heath
107
H17
Empetrum nigrum ssp. hermaphrodi-tum and Loiseleuria procumbens constant with frequent Carex bigelowii,Diphasium alpinum, Antennariadioica, Cladonia uncialis, C. arbuscula,C. gracilis, C. pyxidata, C. bellidiflora,Cetraria glauca, C. islandica, Alectorianigricans and Sphaerophorus globosus.
Loiseleuria procumbens occasional,but Empetrum nigrum ssp. hermaphro-ditum replaced by ssp. nigrum andwith Erica cinerea becoming common.Potentilla erecta very frequent withScirpus cespitosus and stricta oftenpresent. Cladonia uncialis and C. arbuscula remain common butlichen flora not so varied or abundant.
H17a
Loiseleuria procumbens –Cetraria glauca sub-community
In this distinctive sub-community mixtures of Calluna vulgariswith subordinate Arctostaphylos alpinus, Loiseleuria procumbensand Empetrum nigrum ssp.hermaphroditum make up the bulk of the mat with scattered Vaccinium myrtillus and occasional V. vitis-idaea,Arctostaphylos uva-ursi, Juniperuscommunis nana and Salix herbacea.Deschampsia flexuosa occurs sparselywith the above herbs and other moreoccasional species. Small patches of Racomitrium lanuginosum are frequent and there is a rich and extensive lichen flora includingthe species listed above.
H17b
Empetrum nigrum ssp. nigrumsub-community
Calluna vulgaris dominates the sub-shrub mat with Arctostaphylosalpinus constant and Empetrumnigrum ssp. nigrum and Erica cinereaas common associates. Vaccinium myrtillus is again sparse withoccasional Arctostaphylos uva-ursi.Carex bigelowii is less common and Deschampsia flexuosa more frequentthan in H17a, with the other associateslisted above. Among bryophytes Hypnum jutlandicum frequently joins Racomitrium lanuginosum. Lichensare not so varied or abundant as inH17a, but Cladonia uncialis and C. arbuscula remain very common.
108
This community includes a variety of moss-richand grassy sub-shrub vegetation, in whichVaccinium myrtillus is the most frequent ericoid,with Calluna vulgaris only occasional and oftenlacking in vigour. Other sub-shrubs can make asizeable contribution to the canopy; in particularEmpetrum nigrum, usually ssp. hermaphroditum,is most frequent, often forming patches.Vaccinium vitis-idaea is also common.
Among vascular associates Deschampsia flexuosaand Galium saxatile are constant throughout, withNardus stricta, Agrostis canina ssp. montana andPotentilla erecta all very frequent. In some standsthese species account for virtually all the herbaceous cover. The grasses Festuca ovina, Agrostiscapillaris and Anthoxanthum odoratum occur atleast occasionally and increase in frequency andabundance in some sub-communities.
The other element, which is usually promi-nent, comprises bulky mosses. Dicranum scopari-um, Pleurozium schreberi and Hypnum cupressi-forme s.l. are very common throughout, Hylo-comium splendens is also conspicuous and therecan be frequent Rhytidiadelphus loreus, R. squar-
rosus, Plagiothecium undulatum, Dicranummajus and Racomitrium lanuginosum. Somelichens occur frequently although an extensivecarpet is never found. The most common speciesare Cladonia arbuscula, C. impexa and C. uncialis.
This community is typical of moist but free-draining, base-poor to circumneutral soilsover steeper slopes at moderate to high altitudesthrough the uplands of northern Britain. It is large-ly confined to altitudes above 400 m and canextend up to 800 m. It occurs over a wide varietyof bedrocks on a variety of soil profiles whichhave a superficial pH of 3.5-5.5. Typically, howev-er, the soils have a well-developed humic layer.This community is widespread through theuplands of Britain but is particular common innorthern Scotland, where the heart of its rangeoccurs in the central and eastern Highlands, withmore sporadic occurrences to the north-west.
At higher levels this vegetation is probably a natural climax with the floristics and distributionof the community being influenced by snow-lie,but towards the sub-montane zone quite extensivestands of the vegetation have been bioticallyderived as a result of woodland clearance and pasturing. In other places treatments such as burn-ing and grazing have precipitated its spread on toblanket peats.
H18 Vaccinium myrtillus –Deschampsia flexuosa heath
109
H18
Su
b-sh
rubs
oft
en c
o-d
omin
ant
wit
hA
lch
emil
la a
lpin
a an
d/o
r gr
asse
sam
ong
wh
ich
Fes
tuca
ovi
na,
Agr
osti
sca
pil
lari
s an
d A
nth
oxan
thu
m o
dor
a-tu
m a
re e
spec
iall
y co
mm
on. L
uzu
laca
mp
estr
is,C
arex
pil
uli
fera
an
d
C. b
iner
vis
also
com
mon
wit
hP
oten
till
a er
ecta
an
d o
ccas
ion
alC
amp
anu
la r
otu
nd
ifol
ia,V
iola
ri
vin
ian
a an
d R
anu
ncu
lus
acri
s.
H18
c
Ra
com
itri
um
la
nu
gin
osu
m–
Cla
don
iasp
p. s
ub-
com
mu
nit
y
Th
is i
s so
met
imes
dev
elop
ed w
her
ep
eaty
soi
ls h
ave
been
bu
rned
or
ond
egra
ded
bla
nke
t p
eats
. Vac
cin
ium
myr
till
us
or m
ixtu
res
of t
his
wit
hE
mp
etru
m n
igru
m a
re u
sual
ly d
omi-
nan
t, w
ith
sp
arse
pla
nts
of
Cal
lun
a vu
lgar
is a
nd
Vac
cin
ium
vit
is-i
dae
a.D
esch
amp
sia
flex
uos
a an
d F
estu
caov
ina
are
very
fre
quen
t an
d c
an b
eab
un
dan
t, w
ith
oth
er g
rass
es o
nly
occa
sion
al. C
arex
big
elow
ii i
s in
fre-
quen
t bu
t lo
call
y ab
un
dan
t. A
par
t fr
om G
aliu
m s
axat
ile
her
bace
ous
dic
otyl
edon
s ar
e u
nco
mm
on. T
he
only
co
mm
on p
leu
roca
rps
are
Ple
uro
ziu
m
sch
rebe
ri a
nd
Hyp
nu
m c
up
ress
ifor
me
s.l.
Lic
hen
s, h
owev
er, a
re b
est
rep
re-
sen
ted
in
th
is s
ub-
com
mu
nit
y,
par
ticu
larl
y th
e sp
ecie
s li
sted
abo
ve.
Th
is s
ub-
com
mu
nit
y is
fou
nd
th
rou
gh-
out
the
ran
ge o
f H
18.
Cal
lun
a vu
lgar
is s
par
se, a
nd
Ble
chn
um
spic
ant
abse
nt
and
ple
uro
carp
s ra
ther
pat
chy.
Rac
omit
riu
m l
anu
gin
osu
mco
mm
on a
nd
lic
hen
s qu
ite
con
spic
u-
ous,
Cla
don
ia a
rbu
scu
la b
ein
g lo
call
yab
un
dan
t an
d C
. im
pex
a an
d
C. u
nci
alis
occ
asio
nal
.
H18
a
Hyl
ocom
ium
sp
len
den
s–
Rh
ytid
iad
elp
hu
s lo
reu
ssu
b-co
mm
un
ity
Th
is s
ub-
com
mu
nit
y is
gen
eral
lyfo
un
d i
n a
nd
aro
un
d s
now
-bed
s on
acid
ic s
oils
. Su
b-sh
rubs
are
gen
eral
lyd
omin
ant
wit
h V
acci
niu
m m
yrti
llu
su
sual
ly m
ost
abu
nd
ant,
bu
t E
mp
etru
mn
igru
m i
s oc
casi
onal
ly c
o-d
omin
ant
and
in
som
e st
and
s w
ith
Vac
cin
ium
viti
s-id
aea
or V
. uli
gin
osu
m.
Des
cham
psi
a fl
exu
osa
is v
ery
com
mon
and
som
etim
es a
bun
dan
t, b
ut
gras
ses
are
not
as
abu
nd
ant
as i
n H
18b.
A h
igh
freq
uen
cy o
f B
lech
nu
m s
pic
ant
is d
iag-
nos
tic.
Bry
oph
ytes
att
ain
th
eir
mos
td
iver
se a
nd
ext
ensi
ve c
over
her
e,
par
ticu
larl
y th
e sp
ecie
s li
sted
abo
ve.
Lic
hen
s ar
e ge
ner
ally
mu
ch l
ess
obvi
ous,
th
e on
ly f
requ
ent
spec
ies
bein
g C
lad
onia
arb
usc
ula
.
Th
is s
ub-
com
mu
nit
y is
fou
nd
th
rou
gh-
out
the
ran
ge o
f H
18.
Su
b-sh
rubs
gen
eral
ly s
tron
gly
dom
i-n
ant
wit
h t
he
list
ed h
erbs
op
pos
ite
occa
sion
al a
t m
ost.
H18
b
Alc
hem
illa
alp
ina
– C
are
x p
ilu
life
rasu
b-co
mm
un
ity
Th
is s
ub-
com
mu
nit
y is
fou
nd
at
low
eral
titu
des
an
d f
avou
rs s
un
nie
r as
pec
tsw
ith
les
s h
um
ic a
nd
som
etim
es l
ess
base
-poo
r so
ils.
Gra
zin
g of
ten
pla
ys
an i
mp
orta
nt
par
t in
its
dev
elop
men
t.V
acci
niu
m m
yrti
llu
s ca
n b
e qu
ite
abu
nd
ant
but
Em
pet
rum
nig
rum
issc
arce
r th
an i
n H
18a.
Eri
coid
s as
aw
hol
e ar
e of
ten
co-
dom
inan
t w
ith
Alc
hem
illa
alp
ina
in t
he
can
opy
and
/or
wit
h g
rass
es w
hic
h a
re b
est
rep
rese
nte
d h
ere.
Th
ere
is a
var
iety
of
dic
otyl
edon
ous
her
bs i
ncl
ud
ing
the
spec
ies
list
ed a
bove
. Bu
lkie
r m
osse
sca
n b
e qu
ite
freq
uen
t bu
t n
ot w
ith
th
esa
me
abu
nd
ance
an
d v
arie
ty a
s in
H18
a. L
ich
ens
are
spar
se.
Th
is s
ub-
com
mu
nit
y is
esp
ecia
lly
char
acte
rist
ic o
f th
e B
read
alba
ne-
Clo
va r
egio
n.
Cal
lun
a vu
lgar
is q
uit
e co
mm
on a
mon
gth
e su
b-sh
rubs
wit
h B
lech
nu
m s
pic
ant
freq
uen
t.
Mos
ses
form
ing
an e
xten
-si
ve g
rou
nd
car
pet
wit
h H
yloc
omiu
msp
len
den
s an
d
Rh
ytid
iad
elp
hu
s lo
reu
sjo
inin
g P
leu
rozi
um
sch
rebe
ri a
nd
Dic
ran
um
sco
par
ium
.
110
This community consists essentially of a very lowmat, 5-10 cm high, of sub-shrubs with an abun-dance of lichens, often marking stands with a yel-lowish tinge. Lichens are more extensive anddominant than in the Calluna vulgaris – Cladoniaarbuscula heath (H13). Calluna vulgaris is uncom-mon overall and Vaccinium myrtillus is the mostconsistent sub-shrub, being co-dominant in moresheltered situations, although sparse in exposedsites. Vaccinium vitis-idaea is less common, butconstant, and V. uliginosum scarce overall.Empetrum nigrum, almost always ssp. hermaph-roditum, is frequent and can exceed Vacciniumspecies in its cover.
Vascular associates are few but Carex bigelowii,a constant, is frequent and often abundant andmay be co-dominant with the ericoids and lichens.The other common and constant plant isDeschampsia flexuosa. Festuca ovina is also fairly frequent together with several herbs, such asGalium saxatile, in sub-community H19a.
Bryophytes are generally not important andRacomitrium lanuginosum is only abundant inone sub-community. Dicranum fuscescens is quite
frequent or there may only be sparse shoots ofPolytrichum alpestre and P. piliferum.
Much more important are the lichens, particular-ly larger fruticose species such as Cladonia arbuscu-la and C. uncialis, both constants, and less common-ly C. rangiferina and C. gracilis, mixtures of whichcan exceed the sub-shrubs in total cover. Cetrariaislandica and Cornicularia aculeata are also verycommon, often with a variety of other species.
This heath is typical of base-poor soils on moderately sheltered and snow-bound slopes athigh altitudes, particularly in the more continen-tal mountains of northern Britain. The vegetationis strongly montane, being found mainly above650 m up to 1000 m or even beyond, and usuallystands are found in sites with some shelter so thatthere is winter protection from lying snow. It ischaracteristic of acid soils with a superficial pH ofabout 4. It has a similar range to that of H13, beingstrongly concentrated in the central and easternHighlands of Scotland, particularly the Grampians,but also in the mountains of the north-west andthe Southern Uplands and with scattered locali-ties in northern England.
Floristic variation reflects differences in expo-sure and soil type, but overall the vegetation is aclimatic climax.
H19 Vaccinium myrtillus –Cladonia arbuscula heath
111
H19
Vac
cin
ium
myr
till
us
and
Car
exbi
gelo
wii
usu
ally
co-
dom
inan
t am
ong
the
vasc
ula
r p
lan
ts, w
ith
Fes
tuca
ovin
a/vi
vip
ara.
Gal
ium
sax
atil
e fr
e-qu
ent
and
Pot
enti
lla
erec
ta o
ccas
ion
al.
H19
c
Em
pet
rum
nig
rum
ssp
. her
ma
ph
rod
i-tu
m–
Cla
don
iasp
p. s
ub-
com
mu
nit
y
Mix
ed m
ats
of V
acci
niu
m m
yrti
llu
san
d E
mp
etru
m n
igru
m h
erm
aph
rod
i-tu
m p
rovi
de
the
bulk
of
the
vasc
ula
rco
ver,
bu
t ar
e of
ten
exc
eed
ed b
y th
eli
chen
cov
er.
Vac
cin
ium
vit
is-i
dae
aca
n b
e m
oder
atel
y ab
un
dan
t an
d t
her
eis
of
ten
a l
ittl
e C
allu
na
vulg
aris
.D
esch
amp
sia
flex
uos
a is
th
e on
ly
com
mon
gra
ss a
nd
sp
ecie
s li
ke C
arex
pil
uli
fera
an
d G
aliu
m s
axat
ile
are
atth
eir
mos
t in
freq
uen
t. R
acom
itri
um
lan
ugi
nos
um
is
acco
mp
anie
d b
y p
ref-
eren
tial
ly c
omm
on P
leu
rozi
um
sch
re-
beri
,Dic
ran
um
sco
par
ium
an
dP
tili
diu
m c
ilia
re. L
ich
ens
are
very
exte
nsi
ve, w
ith
th
e m
ost
com
mon
spec
ies
list
ed a
bove
.
Th
is s
ub-
com
mu
nit
y is
wid
esp
read
on
gran
itic
an
d q
uar
tzit
ic m
oun
tain
s.
Em
pet
rum
nig
rum
her
map
hro
dit
um
very
com
mon
wit
h l
ich
ens
very
abu
n-
dan
t in
th
e m
at. C
lad
onia
ran
gife
rin
a,C
. gra
cili
s an
d O
chro
lech
ia f
rigi
da
are
pre
fere
nti
ally
fre
quen
t an
d C
. bel
lid
i-fl
ora,
C. p
yxid
ata
and
Cet
rari
a n
ival
ism
ore
occa
sion
al. R
acom
itri
um
lan
ugi
-n
osu
m f
requ
ent
but
not
abu
nd
ant.
H19
b
Ra
com
itri
um
la
nu
gin
osu
msu
b-co
mm
un
ity
Th
e m
at i
s d
omin
ated
by
vari
ous
mix
ture
s of
Vac
cin
ium
myr
till
us,
Car
ex b
igel
owii
,lic
hen
s an
d
abu
nd
ant
Rac
omit
riu
m l
anu
gin
osu
m.
Em
pet
rum
nig
rum
,mos
tly
ssp
. her
-m
aph
rod
itu
m,i
s fa
irly
com
mon
, bu
tV
acci
niu
m v
itis
-id
aea
is v
ery
pat
chy.
Sal
ix h
erba
cea
is o
ccas
ion
al a
s is
th
era
re m
oss
Kia
eria
sta
rkei
bu
t bo
th c
anbe
loc
ally
abu
nd
ant.
Oth
er v
ascu
lar
asso
ciat
es a
re e
ith
er o
ccas
ion
al, a
sab
ove,
or
very
occ
asio
nal
. Th
e li
chen
cove
r is
var
ied
; Cla
don
ia a
rbu
scu
laca
n b
e ab
un
dan
t bu
t m
ay b
e p
atch
yan
d m
ixed
car
pet
s ar
e m
ore
usu
al
wit
h C
. un
cial
is,C
etra
ria
isla
nd
ica,
Cor
nic
ula
ria
acu
leat
a an
dS
ph
aero
ph
oru
s gl
obos
us.
Th
is s
ub-
com
mu
nit
y is
fou
nd
bot
h i
nce
ntr
al a
nd
nor
th-w
est
Sco
tlan
d.
Fes
tuca
ovi
na
and
Gal
ium
sax
atil
e ca
noc
cur
occa
sion
ally
bu
t n
ot i
n a
ny
abu
n-
dan
ce.
H19
a
Fes
tuca
ovi
na
– G
ali
um
sa
xati
lesu
b-co
mm
un
ity
Vac
cin
ium
myr
till
us
is o
ften
abu
nd
ant
and
co-
dom
inan
t w
ith
Car
ex b
igel
owii
.E
mp
etru
m n
igru
m i
s so
met
imes
fou
nd
and
Vac
cin
ium
vit
is-i
dae
a is
mos
t fr
equ
ent
and
abu
nd
ant
her
e.D
esch
amp
sia
flex
uos
a is
mod
erat
ely
abu
nd
ant
and
Gal
ium
sax
atil
e is
ago
od d
iagn
osti
c sp
ecie
s. T
he
lich
enel
emen
t is
pro
min
ent
alth
ough
not
so
exte
nsi
ve a
s in
su
b-co
mm
un
ity
H19
c.C
lad
onia
arb
usc
ula
is s
omet
imes
co-
dom
inan
t w
ith
th
e va
scu
lar
pla
nts
an
dC
. un
cial
is i
s m
oder
atel
y ab
un
dan
t.
Th
is s
ub-
com
mu
nit
y is
mor
e ch
arac
-te
rist
ic o
f th
e li
me-
rich
roc
ks b
etw
een
Bre
adal
ban
e an
d C
lova
, alt
hou
gh t
he
pH
of
the
soil
su
rfac
e is
sti
ll s
tron
gly
acid
.
Rac
omit
riu
m l
anu
gin
osu
m s
omet
imes
quit
e ab
un
dan
t in
a r
ath
er p
atch
yli
chen
cov
er. A
lch
emil
la a
lpin
a fr
e-qu
ent
in s
mal
l am
oun
ts, w
ith
occ
a-si
onal
Sal
ix h
erba
cea
and
Ju
ncu
s tr
ifid
us.
112
This community brings together a variety of vegetation types in which Vaccinium myrtillusand/or Empetrum nigrum ssp. hermaphroditumoccur, occasionally with other sub-shrubs such asV. vitis-idaea, and are co-dominant with Racom-itrium lanuginosum or hypnaceous mosses.Vaccinium myrtillus and E. nigrum form a lowmat, usually less than 10 cm high, appearing as apatchy mosaic of bushes among the moss carpet.At lower altitudes Juniperus communis ssp. nanaand Erica cinerea can show local prominence.
Among vascular associates Carex bigelowii,Festuca ovina/vivipara, Deschampsia flexuosaand Galium saxatile are all constant and frequent.There are few other common herbs, although thegrasses may include frequent Nardus stricta.Huperzia selago and Potentilla erecta are frequentin some stands and may be accompanied byThymus praecox, Viola riviniana and Carexpilulifera.Much of the distinctive character of this vegetation type depends on the cryptogams.
Racomitrium lanuginosum is very important,forming a woolly carpet, and it is found with avariety of other bulky mosses. Hypnum cupressi-forme s.l., Hylocomium splendens, Rhytid-iadelphus loreus and Pleurozium schreberi are allconstant and can be prominent. Additionally,Polytrichum alpinum and Dicranum scopariumare found in many stands. Common hepatics arePtilidium ciliare and Diplophyllum albicans, buttheir greatest variety is found in the Bazzania –Mylia sub-community. Lichens are less important,but Cladonia uncialis and C. arbuscula are most frequent throughout and may be modestly abundant, with C. gracilis and Cetraria islandicaalso common.
This heath is characteristic of humic, base-poorsoils on fairly exposed slopes and summits atmoderate to high altitudes, in the cool oceanicmountains of north-west Scotland, extending toSkye, and scattered through the Grampians.Almost always, the bedrocks underlying thisheath are siliceous in character.
Climatic differences and some modest varia-tion in edaphic conditions influence the floristics,but this is essentially climax vegetation.
H20 Vaccinium myrtillus –Racomitrium lanuginosum heath
113
H20
Vac
cin
ium
vit
is-i
dae
a ve
ry s
carc
e, b
ut
Cal
lun
a vu
lgar
is,E
rica
cin
erea
an
dJu
nip
eru
s co
mm
un
is n
ana
occa
sion
alw
ith
Alc
hem
illa
alp
ina
som
etim
es c
o-d
omin
ant.
Pot
enti
lla
erec
ta,T
hym
us
pra
ecox
,Vio
la r
ivin
ian
a an
d C
arex
pil
uli
fera
fre
quen
t.
Dip
lop
hyl
lum
alb
ican
s an
d A
nas
trep
taor
cad
ensi
s so
met
imes
fou
nd
bu
t co
m-
bin
atio
ns
of t
hes
e ot
her
bry
oph
ytes
rare
.
H20
c
Ba
zza
nia
tri
cren
ata
– M
ylia
ta
ylor
isu
b-co
mm
un
ity
Her
e th
e ge
ner
al f
lori
stic
fea
ture
s ar
eas
in
H20
b th
ough
Ble
chn
um
sp
ican
tan
d J
un
cus
trif
idu
s ar
e fr
equ
ent.
Th
eco
mm
un
ity
mos
ses
are
wel
l re
pre
sen
t-ed
bu
t d
isti
nct
ivel
y th
ere
is a
ran
ge o
fco
nsp
icu
ous
bryo
ph
ytes
, in
clu
din
gA
tlan
tic
hep
atic
s as
lis
ted
abo
ve.
Lic
hen
s ar
e ge
ner
ally
sp
arse
.
Th
is s
ub-
com
mu
nit
y is
ver
y m
uch
con
fin
ed t
o th
e w
ette
st r
egio
ns
and
even
th
en i
t is
res
tric
ted
to
suit
able
cold
an
d d
amp
asp
ects
.
Vac
cin
ium
vit
is-i
dae
a ve
ry c
omm
onan
d a
ll o
ther
lis
ted
ass
ocia
tes
scar
ce.
H20
a
Vio
la r
ivin
ian
a–
Th
ymu
s p
raec
oxsu
b-co
mm
un
ity
Th
e su
b-sh
rub
mat
is
mor
e va
ried
th
an u
sual
in
th
e co
mm
un
ity.
Em
pet
rum
nig
rum
her
map
hro
dit
um
and
Vac
cin
ium
myr
till
us
can
bot
h b
eab
un
dan
t, b
ut
Alc
hem
illa
alp
ina
can
be c
o-d
omin
ant
and
mor
e lo
call
yJu
ncu
s co
mm
un
is s
sp. n
ana
or E
rica
cin
erea
may
occ
ur
wit
h s
par
se s
hoo
tsof
Cal
lun
a vu
lgar
is. H
erbs
ch
arac
teri
s-ti
c of
H20
, su
ch a
s F
estu
ca o
vin
a/vi
vip
ara,
Des
cham
psi
a fl
exu
osa
and
Gal
ium
sax
atil
e, r
emai
n v
ery
freq
uen
tan
d a
re jo
ined
pre
fere
nti
ally
by
the
her
bs l
iste
d a
bove
. Th
e cr
ypto
gam
flor
a is
poo
r, w
ith
Rac
omit
riu
m
lan
ugi
nos
um
as
the
typ
ical
dom
inan
t,bu
t ot
her
ple
uro
carp
s ar
e le
ss f
requ
ent
and
Dip
lop
hyl
lum
alb
ican
s is
th
e on
lyco
mm
on h
epat
ic.
Th
is s
ub-
com
mu
nit
y ex
ten
ds
the
ran
geof
H20
in
to t
he
mil
der
foo
thil
ls o
f th
ew
este
rn s
eabo
ard
an
d S
kye.
Ric
h a
nd
lu
xuri
ant
pat
chw
ork
ofbr
yop
hyt
es p
rese
nt
amon
g th
eR
acom
itri
um
lan
ugi
nos
um
car
pet
wit
hD
icra
nu
m s
cop
ariu
m,P
lagi
oth
eciu
mu
nd
ula
tum
,Sp
hag
nu
m c
apil
lifo
liu
m,
Myl
ia t
aylo
ri,D
iplo
ph
yllu
m a
lbic
ans,
Ple
uro
zia
pu
rpu
rea,
Baz
zan
ia t
ricr
ena-
ta,S
cap
ania
gra
cili
s,S
. orn
itho
podi
-oi
des,
Ana
stre
pta
orca
dens
isan
dA
nth
elia
jula
cea
freq
uen
t.
H20
d
Rh
ytid
iad
elp
hu
s lo
reu
s–
Hyl
ocom
ium
sp
len
den
ssu
b-co
mm
un
ity
Alt
hou
gh R
acom
itri
um
lan
ugi
nos
um
is
gen
eral
ly r
edu
ced
in
cov
er, t
he
gen
eral
vege
tati
on f
eatu
res
acco
rd w
ell
wit
hth
e co
mm
un
ity
as a
wh
ole.
Vac
cin
ium
viti
s-id
aea
is p
refe
ren
tial
ly c
omm
on,
Car
ex b
igel
owii
an
d D
esch
amp
sia
flex
-u
osa
are
freq
uen
t an
d G
aliu
m s
axat
ile
and
Fes
tuca
ovi
na/
vivi
par
a ar
e m
ore
occa
sion
al. T
he
mos
s m
at i
s d
isti
nct
ive
wit
h d
omin
ance
pas
sin
g to
th
e sp
ecie
sli
sted
abo
ve. T
he
Atl
anti
c h
epat
ics
fou
nd
in
H20
c ar
e ab
sen
t.
Th
is s
ub-
com
mu
nit
y is
loc
al t
hro
ugh
-ou
t th
e ra
nge
of
H20
.
H20
b
Cet
rari
a i
sla
nd
ica
sub-
com
mu
nit
y
Mix
ture
s of
Em
pet
rum
nig
rum
ssp
.h
erm
aph
rod
itu
m a
nd
Vac
cin
ium
myr
-ti
llu
s w
ith
abu
nd
ant
Rac
omit
riu
mla
nu
gin
osu
m a
re u
sual
ly d
omin
ant.
Gra
sses
lik
e F
estu
ca o
vin
a/vi
vip
ara,
Des
cham
psi
a fl
exu
osa,
Nar
du
s st
rict
a,A
gros
tis
can
ina
and
An
thox
anth
um
odor
atu
m t
end
to
be p
rom
inen
t, b
ut
the
rich
nes
s of
vas
cula
r p
lan
ts i
n H
20a
is a
bsen
t. B
ryop
hyt
es a
re n
ot n
um
er-
ous
alth
ough
com
mu
nit
y co
nst
ants
are
all
com
mon
wit
h f
requ
ent
Hyp
nu
mcu
pre
ssif
orm
e s.
l. a
nd
Pol
ytri
chu
mal
pin
um
. Th
e li
chen
flo
ra i
s a
litt
leri
cher
th
an u
sual
wit
h t
he
spec
ies
list
ed a
bove
pre
sen
t.
Th
is i
s th
e m
ost
wid
esp
read
an
d c
om-
mon
su
b-co
mm
un
ity
over
all.
Rac
omit
riu
m l
anu
gin
osu
m r
edu
ced
in
cove
r w
ith
dom
inan
ce o
ften
pas
sin
g to
mix
ture
s of
Ple
uro
ziu
m s
chre
beri
,H
yloc
omiu
m s
ple
nd
ens
and
Rh
ytid
iad
elp
hu
s lo
reu
s.
Bu
lky
ple
uro
carp
s ca
n b
e co
mm
on
but
not
abu
nd
ant
amon
g th
e d
omin
ant
Rac
omit
riu
m l
anu
gin
osu
m c
arp
et, b
ut
the
lich
en c
arp
et i
s ri
cher
wit
h f
re-
quen
t C
lad
onia
gra
cili
s,C
etra
ria
isla
nd
ica
and
Cor
nic
ula
ria
acu
leat
a,an
d o
ccas
ion
al C
lad
onia
leu
cop
hae
a,S
ph
aero
ph
oru
s gl
obos
us
and
Ale
ctor
ian
igri
can
s.
114
This community has a mixed canopy of sub-shrubs, usually 30-50 cm high, with a damp layerof luxuriant bryophytes. Calluna vulgaris is usual-ly the dominant ericoid, although Vaccinium myr-tillus is constant and Empetrum nigrum, almostalways ssp. hermaphroditum, very frequent. Ericacinerea is also frequent, but patchy. Other sub-shrubs are only occasional.
Deschampsia flexuosa and Potentilla erecta areconstant and very common though usually presentas sparse, scattered individuals. More distinctive-ly Blechnum spicant is constant and Solidago virgaurea and Listera cordata frequent. There areonly occasional records for other vascular associates.
The bryophytes form an extensive and lush car-pet. Constant throughout are bulky hypnaceous mosses such as Hypnum cupressiforme s.l.,Rhytidiadelphus loreus, Pleurozium schreberi andHylocomium splendens, with Plagiothecium undu-latum, Dicranum scoparium and D. majus alsovery common. Particularly distinctive is the highfrequency and local abundance of Sphagnumcapillifolium. Racomitrium lanuginosum becomesmore frequent at higher altitudes. The most spec-tacular enrichment in this element comes fromoceanic hepatics and this community is a major
locus for the ‘mixed northern hepatic mat’.Species such as Scapania gracilis, Mylia taylori and Diplophyllum albicans can be foundthroughout, but the Mastigophora – Herbertussub-community has an additional range of Atlanticspecies, forming a unique vegetation found at high-er altitudes in north-west Scotland where summertemperatures are lower and rainfall higher. Lichensare fairly insignificant, Cladonia impexa being theonly species occurring commonly throughout.
This heath is highly characteristic of fragmen-tary humic soils, developed in situations with acool but equable climate and a consistently shadyand extremely humid atmosphere. It is almostwholly confined to low to moderate altitudesthrough the oceanic mountains of north-westScotland and on Skye, with outliers on Orkney, insouth-west Scotland and the Lake District.
It is largely restricted to steep, sunless slopes ofnorth-west to easterly aspect, often with rock outcrops and blocky talus, among which crevicesprovide additional shade. In some situations thismay not be a climax community but a result ofwoodland clearance, but towards the upper end ofits altitudinal limits this heath appears to form anatural component of vegetation patterns con-trolled largely by variations in local climates andsoils. It is sometimes lightly grazed, but burningis very damaging and recovery is probablyextremely slow. It seems certain that the extent ofthis community has been reduced by burning.
H21 Calluna vulgaris –Vaccinium myrtillus – Sphagnumcapillifolium heath
115
H21
Empetrum nigrum hermaphroditum frequent and locallyabundant among the sub-shrubs with especially rich andluxuriant cryptogam carpets among which there is frequentRacomitrium lanuginosum, Mylia taylori, Scapania gracilis,Bazzania tricrenata, Pleurozia purpurea, Diplophyllum albicans, Anastrepta orcadensis, Mastigophora woodsii,Herbertus aduncus hutchinsiae, Cladonia uncialis and C. arbuscula.
Empetrum nigrum hermaphroditum local and combina-tions of listed cryptogams rare, but Dicranum scopariumcommon with frequent fronds of Pteridium aquilinum.
H21b
Mastigophora woodsii – Herbertus aduncus ssp. hutchinsiae sub-community
Calluna vulgaris is usually the most abundant sub-shrub,but the canopy is short and more mixed than in H21a. Thebryophytes are extremely well developed. Among the moss-es all the community constants occur frequently. The hepat-ics, however, are most abundant, tingeing the vegetationwith a variety of colours. They include the species listedabove with other rarer Atlantic hepatics.
This sub-community is restricted in range, being confined to the more shaded and humid habitats in north-westScotland.
H21a
Calluna vulgaris – Pteridium aquilinumsub-community
This sub-community occurs in sites which cannot supportthe full range of hepatics. Calluna vulgaris is generally astrong dominant in this taller and more species-poorheath. Vaccinium myrtillus is very common with Ericacinerea and Vaccinium vitis-idaea occasional. Other vascu-lar plants are sparse, but distinctive is Pteridium aquil-inum with occasional Oxalis acetosella, Viola rivinianaand Luzula sylvatica. Bryophytes can have fairly highcover, but comprise almost entirely the community constants.
This sub-community is found throughout the range of H21.
116
This heath has a mixed cover of sub-shrubs over amoist cover of bryophytes similar to that of Calluna vulgaris – Vaccinium myrtillus –Sphagnum capillifolium heath (H21). However,here the canopy is not as tall, being mostlybetween 10 and 30 cm high, and Calluna vulgarisis not invariable in its dominance (Vacciniummyrtillus is dominant in the Polytrichum – Galiumsub-community). Empetrum nigrum ssp. her-maphroditum is constant, as is V. vitis-idaea(although less frequent), and V. uliginosum is rare.Erica cinerea is absent.
The vascular associates are distinctive because,with constant Deschampsia flexuosa, there is frequently a little Rubus chamaemorus andCornus suecica. Eriophorum vaginatum can belocally abundant and there are records forPotentilla erecta, Melampyrum pratense,Listera cordata, Juncus squarrosus and Nardusstricta.
Bryophytes are always conspicuous and sometimes very abundant. Dicranum scopariumand the hypnaceous mosses Pleurozium schreberi,Hylocomium splendens and Rhytidiadelphusloreus are the most consistent and constant,although Sphagnum spp. can also have a highcover, with the constant S. capillifolium being
especially common and several other specieslocally abundant. A variety of other mosses andhepatics are variable in their occurrence. Lichensare typically less prominent, although Cladoniaarbuscula is constant and can show modest abundance.
This heath is characteristic of wet, base-poorpeats at moderate to high altitudes (mainly between500 m and 800 m), where there is protection againstextremes of dryness and winter cold by virtue of anoceanic influence or locally prolonged snow-lie.The profiles found beneath this community aretypically poorly-developed, often consisting ofjust a layer of bryophyte or ericoid humus restingdirectly on blocky talus, derived from a variety ofpervious bedrocks. It is almost entirely confined tothe central and north-west Highlands of Scotland.In the former region it is typical of early snow-bedswhere it is mainly present as the Polytrichum –Galium sub-community. In the north-west High-lands, where the climate is ameliorated by theoceanic climate, this heath is generally representedby the Plagiothecium – Anastrepta sub-community.
Climatic and edaphic factors maintain thisheath as a climax vegetation in most situations,although at its lowest limits it falls within the alti-tudinal range of historical pine forest. It is some-times affected by grazing and burning where thesetreatments are applied to the surrounding heaths.Burning is deleterious to the floristic richness ofthe community.
H22 Vaccinium myrtillus –Rubus chamaemorus heath
117
H22
Carex bigelowii frequent in small amounts with a rich and extensive patchwork of cryptograms, among whichRacomitrium lanuginosum, Plagiothecium undulatum,Ptilidium ciliare, Anastrepta orcadensis, Barbilophozia floerkii, Cladonia bellidiflora, C. uncialis, C. leucophaea,C. gracilis and C. impexa are very common.
Carex bigelowii and cryptogams listed opposite all veryscarce, but Gallium saxatile and Blechnum spicant frequentas scattered individuals and Polytrichum commune verycommon among usually plentiful hypnaceous mosses.
H22b
Plagiothecium undulatum – Anastrepta orcadensissub-community
Calluna vulgaris is often a strong dominant in a tallercanopy with Empetrum nigrum ssp. hermaphroditum occasionally abundant. Vaccinium myrtillus usually has lowcover and V. vitis-idaea occurs unevenly. Cornus suecica,Rubus chamaemorus and Deschampsia flexuosa are allmore patchy than in H22a, though Eriophorum vaginatum iscommon as scattered shoots. Carex bigelowii and Huperziaselago are preferential at low frequencies. The cryptogamsare distinctive with both hypnaceous mosses andSphagnum spp. prominent together with a number ofAtlantic hepatics including the species listed above. Lichensare also more numerous in this sub-community with theabove species present and Cladonia arbuscula constant.
This sub-community occurs throughout the range of H22and is particularly well-developed in the north-westHighlands.
H22a
Polytrichum commune – Galium saxatile sub-community
Vaccinium myrtillus is generally dominant in a low sub-shrub canopy with Calluna vulgaris and/or Empetrumnigrum ssp. hermaphroditum sub-dominant. Vacciniumvitis-idaea is fairly common but of low cover. Cornus sueci-ca and Rubus chamaemorus are most consistently frequenthere though not abundant. Deschampsia flexuosa is ratherpatchy and Blechnum spicant and Galium saxatile are preferentially common. Hypnaceous mosses, especiallyHylocomium splendens and Rhytidiadelphus loreus, areplentiful with Sphagnum capillifolium patchily abundant.Lichens are rare apart from scattered Cladonia arbuscula.
This sub-community is largely restricted to the centralHighlands.
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The Joint Nature Conservation Committee is the forumthrough which the three country nature conservation agencies –the Countryside Council for Wales (CCW), English Nature(EN) and Scottish Natural Heritage (SNH) – deliver theirstatutory responsibilities for Great Britain as a whole andinternationally. These responsibilities, known as the specialfunctions, contribute to sustaining and enriching biologicaldiversity, enhancing geological features and sustaining natural systems.
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