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.