Post on 19-Jul-2020
transcript
Do lichens prevent pine stand
reclosure in the boreal forest?
Marine Pacé PhD student in environmental sciences
Nicole Fenton, David Paré, Yves Bergeron
Introduction
Pine stands on sandy soil in the boreal forest
Productive pine stand
1/15
Introduction
Canopy opening
Pine stands on sandy soil in the boreal forest
Productive pine stand
1/15
Introduction
Lichen woodland Stable alternative state*
Pine regeneration
deficit
Pine stands on sandy soil in the boreal forest
Productive pine stand Canopy opening
* Jasinsky and Payette 2005 1/15
Lichen woodland
Productive pine stand
Introduction
Feather mosses including Pleurozium
Lichens
Pine stands on sandy soil in the boreal forest
Canopy opening
Stable alternative state
Pine regeneration
deficit
1/15
Introduction
Do lichens play a role in maintaining open lichen woodlands in the boreal forest?
Suspect 001
Pine stands on sandy soil in the boreal forest
Productive pine stand Canopy opening
Lichen woodland Stable alternative state
Pine regeneration
deficit
Introduction
Do lichens affect jack pine germination and/or growth?
Question :
And if so, how?
2/15
Experimental design
Tree Ground cover Fertilization
Jack pine
bare soil
vs
Feather mosses
vs
Lichen
Control vs Fertilized
Application of various treatments…
X
3/15
Stage of growth Design
Germination Ex situ*
Seedling growth Ex situ*
Young tree growth
In situ Ex situ*
… at different stages of pine development
* Substrate from the field
Experimental design
4/15
Stage of growth Design Treatment application
Germination Ex situ*
Direct exposition
Seedling growth Ex situ*
Young tree growth
In situ Ex situ*
Direct exposition
Indirect exposition
Experimental design
… at different stages of pine development
* Substrate from the field 4/15
Germination
Results G
erm
inat
ion
su
cces
0.
00.
20.
40.
60.
81.
0
Index
Réu
ssite
ger
min
atio
n
0.0
0.2
0.4
0.6
0.8
1.0
Index
Réu
ssite
ger
min
atio
n
0.0
0.2
0.4
0.6
0.8
1.0
Index
Ré
uss
ite g
erm
ina
tion
5/15
Germination
Positive effect of the ground cover
*
0.0
0.2
0.4
0.6
0.8
1.0
Index
Réu
ssite
ger
min
atio
n
0.0
0.2
0.4
0.6
0.8
1.0
Index
Réu
ssite
ger
min
atio
n
0.0
0.2
0.4
0.6
0.8
1.0
Index
Ré
uss
ite g
erm
ina
tion
A B
Ge
rmin
atio
n s
ucc
es
Results
5/15
Seedling growth D
ry b
iom
ass
(g/p
ot)
0.0
0.2
0.4
0.6
0.8
1.0
Index
Bio
ma
sse
sè
ch
e(g
/pla
ntu
le)
Results
6/15
0.0
0.2
0.4
0.6
0.8
1.0
Index
Bio
ma
sse
sè
che
(g/p
lan
tule
)
0.0
0.2
0.4
0.6
0.8
1.0
Index
Bio
ma
sse
sè
ch
e(g
/pla
ntu
le)
Results Seedling growth
Dry
bio
mas
s (g
/po
t)
6/15
0.0
0.2
0.4
0.6
0.8
1.0
Index
Bio
ma
sse
sè
che
(g/p
lan
tule
)
***
Positive effect of feather mosses
0.0
0.2
0.4
0.6
0.8
1.0
Index
Bio
ma
sse
sè
ch
e(g
/pla
ntu
le)
a
b b
Results Seedling growth
Dry
bio
mas
s (g
/po
t)
6/15
Young tree growth ex situ
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C- C+ M- M+ L- L+-15
-10
-50
5
Rel
ativ
e gr
ow
th (
SU)
6
4
Ro
ots
0
Ab
ove
2
Results
7/15
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C- M- L-
-6-4
-20
2
Negative effect of lichens on root growth
A A A
ab
a b
≈
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C- M- L-
-6-4
-20
2
Results Young tree growth ex situ
Rel
ativ
e gr
ow
th (
SU)
6
4
Ro
ots
0
Ab
ove
2
7/15
R
elat
ive
gro
wth
(SU
)
3
Ro
ots
0
A
bo
ve
3
Young tree growth in situ
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C CO M MO L LO
-3-2
-10
12
3
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C M L
-3-2
-10
12
3
Results
8/15
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C CO M MO L LO
-3-2
-10
12
3
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C M L
-3-2
-10
12
3
Negative effect of lichens on pine growth
A B
?
Results R
elat
ive
gro
wth
(SU
)
3
Ro
ots
0
A
bo
ve
3
Young tree growth in situ
8/15
Index
Rela
tive d
iffere
nce
betw
een in
itial a
nd f
inal b
iom
ass
es
(%)
C M L-8-6
-4-2
02
4
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C M L-8-6
-4-2
02
4
Rel
ativ
e gr
ow
th (
SU)
-8
Ro
ots
-
2
0
A
bo
ve
4
Young tree growth ex situ – indirect exposition
Results
9/15
Index
Rela
tive d
iffere
nce
betw
een in
itial a
nd f
inal b
iom
ass
es
(%)
C M L-8-6
-4-2
02
4
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C M L-8-6
-4-2
02
4
A A A
a a
b * ≈
Results
Negative effect of the lichen leachates on root growth
Rel
ativ
e gr
ow
th (
SU)
-8
Ro
ots
-
2
0
A
bo
ve
4
Young tree growth ex situ – indirect exposition
9/15
Young tree growth ex situ
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C- C+ M- M+ L- L+-15
-10
-50
5
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C- C+ M- M+ L- L+-15
-10
-50
5
Negative effect of lichens on root growth
A A A
ab
a b
Rel
ativ
e gr
ow
th (
SU)
1
5
10
R
oo
ts
0
A
bo
ve
5
≈
Results
10/15
≈
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C- C+ M- M+ L- L+-15
-10
-50
5
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C- C+ M- M+ L- L+-15
-10
-50
5
A A A
ab
a b
Rel
ativ
e gr
ow
th (
SU)
1
5
10
R
oo
ts
0
A
bo
ve 5
Results Young tree growth ex situ
10/15
≈
Young tree growth ex situ
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C- C+ M- M+ L- L+-15
-10
-50
5
Index
Rela
tive d
iffe
rence b
etw
een initia
l and f
inal bio
masses (
%)
C- C+ M- M+ L- L+-15
-10
-50
5
***
A A A
ab
a b
B B B
c c
abc
Results
Positive effect of fertilisation regardless of the cover
Rel
ativ
e gr
ow
th (
SU)
1
5
10
R
oo
ts
0
A
bo
ve 5
10/15
Suspect 001
* Reference = bare soil
Results Lichen and feather moss effects on pine growth*
11/15
Suspect 001
Results
* Reference = bare soil
Lichen and feather moss effects on pine growth*
11/15
Suspect 001
Results
* Reference = bare soil
Lichen and feather moss effects on pine growth*
11/15
Suspect 001
Results Lichen and feather moss effects on pine growth*
* Reference = bare soil 11/15
Lichen has a globally negative effect on pine growth: some clues on is M.O.?
Suspect 001
Results
* Reference = bare soil
Lichen and feather moss effects on pine growth*
11/15
Suspect 001
Results
* Reference = bare soil
Lichen has a globally negative effect on pine growth: some clues on is M.O.?
Lichen and feather moss effects on pine growth*
11/15
Discussion Effect via soil moisture
Higher moisture under lichens …
12/15
Discussion
… Related to different rates of evapotranspiration …
Effect via soil moisture
12/15
Discussion
… But also to the emission by lichens of a slimy substance that reduced the drainage …
Effect via soil moisture
12/15
Discussion
… Contrasted effects depending on the stage of pine development.
Effect via soil moisture
12/15
Discussion Effect via soil moisture
… Contrasted effects depending on the stage of pine development.
12/15
Discussion
NPK
Overall less soil nutrients under lichens …
NPK
Effect via soil nutrients
13/15
Discussion
High fertilization = should reduce the difference between lichens and feather mosses
NPK NPK
Soil nutrients
13/15
Discussion
… However, the positive effect of fertilization is the same regardless of the ground cover …
NPK NPK
Soil nutrients
13/15
Discussion
… And tree growth on lichen ground cover remains lower despite the fertilization …
NPK NPK
Effect via soil nutrients
13/15
Discussion
The negative effects of lichen are not only linked to soil nutrients.
NPK NPK
Effect via soil nutrients
13/15
Discussion
Negative effect of lichen leachates on tree growth Direct effect …
Effect via soil solution
14/15
Discussion
…Or indirect via the soil biological communities
Effect via soil solution
14/15
Conclusion
Suspect 001
• Lichens affect jack pine development at different stages
• Effect via nutrients, but not only… • Effect via the soil solution, allelopathy ?
15/15
Conclusion
Suspect 001
Lichens are likely to contribute to the absence of stand reclosure in the boreal forest.
• Lichens affect jack pine development at different stages
• Effect via nutrients, but not only… • Effect via the soil solution, allelopathy ?
15/15
Thanks for your attention !
Aknowlegments
Hugues, Linda, Nicole, Franck, Denis, Sylvie, Armand, Michel, Marie-
Hélène, Serge, Sébastien, Jacques, Fanny, Laurence, Samuel, Jonathan, Pauline, Lili, Benjamin, Roch, Danielle, Danièle, Marc, Raynald, Marie…
And to all the people who have contributed to this study… Thanks !