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Satoyama woodland management and mass
mortality of oak trees
ITÔ, HirokiForestry and Forest Products Research Institute
2014-10-23
Satoyama as
• Woodlands
• Landscapes
• Systems
Satoyama woodlands
19c. KyôtoOgura (2011)
Overuse
Underuse
Satoyama landscapesTakeuchi (2003)
Satoyama systemsFukamachi and Oku (2011)
Satoyama woodlands• Satoyama woodlands had been maintained to obtain
charcoal woods, fuel woods, green manure and other materials.
• Most of them were managed as pine forests or as coppices that were consisted of oaks.
• Most of them have been abandoned from 1960–70s because fossil fuel replaced charcoal and fuel woods.
• After 1990s, mass mortality of oak trees has expanded in Japan.
Some Satoyama woodlands are still
managed as coppices
Charcoal
Bed logs for mushroom cultivation
Coppices in EnglandRackham (1986)
Coppice management and species abundance
in floor vegetation
Study site
Inagawa Town
Coppice still managed
Coppice still managed
Stump
Pollard
Abandoned broadleaved forest
Abandoned pine forest
Coppice had more plant species in floor vegetation than abandoned forests (Itô et al. 2010)
Stand type
No.
spe
cies
0
10
20
30
40
50
60
70
1 2 3 4 5
year
2006
2007
2008
Cleared in 2007
Cleared in 2005
Cleared in 2001
Broad-leaved Pine
Coppices Abandoned forests
Stand type
Light-demanding herbaceous species can survive on coppice floor
Siphonostegia laetaオオヒキヨモギ, Red-listed (VU)
Monochasma sheareriクチナシグサ
Tricyrtis affinisヤマジノホトトギス
Simulation• Itô et al. (2012) constructed a simple simulation model to estimate
fluctuations of floor species abundance with 6 conditions:
• A: 1 of 10 stands were cleared each year
• B: 10 of 10 stands were simultaneously cleared every decade
• C: 5 of 10 stands were cleared every 5 years
• D: 10 of 10 stands were cleared each year
• E: abandoned broadleaved forest left unmanaged
• F: abandoned pine forest left unmanaged
1 2 3 4 5
6 7 8 9 10
10 10 10 10 10
10 10 10 10 10
1 1 1 1 1
6 6 6 6 6
1 1 1 1 1
1 1 1 1 1
A: 1 of 10 stands were cleared each year
B: 10 of 10 stands were simultaneously cleared every decade
C: 5 of 10 stands were cleared every 5 years
D: 10 of 10 stands were cleared each year
Result of the simulation suggested that shifting mosaic (A and C) would keep richer species in
floor (Itô et al., 2012).
Year
Expe
cted
num
ber o
f spe
cies
40
60
80
100
40
60
80
100
A
D
5 10 15 20
B
E
5 10 15 20
C
F
5 10 15 20
Itô et al. Fig.2
Summary
• Coppices under management can hold more floor species than abandoned forests.
• Shifting mosaic can keep stable floor species abundance.
Mass mortality of oak trees
Expansion of the mortality(Kuroda, 2008)
~1980 ~2007
Damaged volume of oak trees
0
10
20
30
40
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Stem
vol
ume
(×10
4 m3 )
Year(Forestry agency of Japan, 2014)
Cause
• The mortality is caused by a species of fungi (Raffaelea quercivora), which is dispersed by a species of beetle (Platypus quercivorus).
• Abandonment of Satoyama woodlands would affect it indirectly.
Platypus quercivorushttps://www.ffpri.affrc.go.jp/labs/seibut/bcg/bcg00039.html
Mortality of oak species
Quercus crispula Quercus serrata
Fagus is not vulnerable.
Evergreen Quercus (eg. Q. glauca) and Castanopsis are also influenced.
>
Case studies in Kansai area
• We studied 3 sites.
• Regeneration?
• What species are regenerating after the mass mortality?
KeihokuKutuki
Miyazu
Kutuki
KeihokuKutuki
Miyazu
樹高(m)
幹数(本)
051015202530
051015202530
051015202530
051015202530
051015202530
051015202530
051015202530
051015202530
plot 1
5 10 15 20
plot 2
5 10 15 20
plot 3
5 10 15 20
アカマツ
アカマツ(枯)
ミズナラ
ミズナラ(枯)
コナラ
コナラ(枯)
ソヨゴ
他
Pinus densiflora
Pinus densiflora (dead)
Quercus crispula
Quercus crispula (dead)
Quercus serrata
Quercus serrata (dead)
Ilex pedunculosa
Other species
Height (m)
Num
ber o
f ste
ms
樹高(m)
幹数(本)
024681012
024681012
024681012
024681012
plot 1
5 10 15 20
plot 2
5 10 15 20
plot 3
5 10 15 20
ミズナラ
ミズナラ(枯)
コナラ
コナラ(枯)
Quercus crispula
Quercus crispula (dead)
Quercus serrata
Quercus serrata (dead)
Height (m)
Num
ber o
f ste
ms
Species in the gaps
Magnolia salicifoliacanopy species
Magnolia obovatacanopy species
Ilex pedunculosasub-canopy species
• Regenerating trees
• Dense sub-canopy and shrub layer may suppress regeneration of tree species.
Keihoku
KeihokuKutuki
Miyazu
樹高(m)
幹数(本)
0
50
100
150
0
50
100
150
0
50
100
150
0
50
100
150
0
50
100
150
0
50
100
150
0
50
100
150
5 10 15
ミズナラ
ミズナラ(枯)
コナラ
イヌブナ
ソヨゴ
コバノミツバツツジ
他
Quercus crispula
Quercus serrata
Ilex pedunculosa
Other species
Height (m)
Num
ber o
f ste
ms
Quercus crispula (dead)
Fagus japonica
Rhododendron reticulatum
樹高(m)
幹数(本)
02468101214
02468101214
02468101214
5 10 15
ミズナラ
ミズナラ(枯)
コナラ
Height (m)
Num
ber o
f ste
ms
Quercus crispula
Quercus serrata
Quercus crispula (dead)
Species in the gaps
Fagus japonicacanopy species
Rhododendron reticulatumshrub species
Pieris japonicashrub species, deer unpalatable
• Regenerating trees
• Fagus japonica
• Effects of deer?
• Unpalatable species (eg. Pieris japonica) in the shrub layer
Miyazu
KeihokuKutuki
Miyazu
胸高直径(cm)
幹数(本)
01020304050
01020304050
01020304050
01020304050
01020304050
01020304050
01020304050
plot 1
0 10 20 30 40 50
plot 2
0 10 20 30 40 50
plot 3
0 10 20 30 40 50
plot 4
0 10 20 30 40 50
ミズナラ
ミズナラ(枯)
リョウブ
オオカメノキ
ハイイヌガヤ
クロモジ
他
Quercus crispula
Clethra barbinervis
Cephalotaxus harringtonia var. nana
Other species
Diameter at breast height (cm)
Num
ber o
f ste
ms
Quercus crispula (dead)
Viburnum furcatum
Lindera umbellata
胸高直径(cm)
幹数(本)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
plot 1
0 10 20 30 40 50
plot 2
0 10 20 30 40 50
plot 3
0 10 20 30 40 50
plot 4
0 10 20 30 40 50
ミズナラ
ミズナラ(枯)
Quercus crispula
Diameter at breast height (cm)
Num
ber o
f ste
ms
Quercus crispula (dead)
Species in the gaps
Viburnum furcatumsub-canopy species
Clethra barbinervissub-canopy species
Cephalotaxus harringtonia var. nanasub-canopy species
Dense Sasa undergrowthsuppresses seedling regeneration
Cephalotaxus harringtonia
var. nanaThere were some seedlings
under Sasa.
• Sasa covered most part of the forest floor.
• Few tree species regenerated in the gaps created by the mass mortality of oak trees.
Under threat of deer
Sika deerCervus nippon
Deer browsingdamages sprouting (Quercus glauca)
Deer-proof fencemore costs for wood production
Summary
• Coppices under management can maintain rich floor plant species.
• Mass mortality of oak trees may change woodland composition.
• Deer may impact managed coppices.