tree regeneration vulnerability to climate change ... · belledonne cerces field experiment...
TRANSCRIPT
Georges Kunstler, Emmanuel Defossez, Benoît Courbaud
Tree regeneration vulnerability to climate change:relative contribution of direct climate effect, plant interactions, herbivores & pathogens
Tackling climate change : the contribution of forest scientific knowledge. Tours 21 May 2012
Mountain Forests & climatic gradients
500 m 500 m
1000 m1000 m
2000 m2000 m
Quercus
FagusFagus QuercusQuercus
Fagus-Abies-Picea
Picea
PinusPinusClimate Change
Regeneration ?
Elevation range
Tree regeneration
Regeneration (Grubb 1977)
High vulnerability of seedlings
Seedling
ClimateT°/ precipitation
Direct & indirect climate effects on tree regeneration
Seedling
Adult tree
Insects herbivory
Soil µ-organismes
ClimateT°/ precipitation
Ground vegetation
Direct & indirect climate effects on tree regeneration
Seedling
Adult tree
Insects herbivory
Soil µ-organismes
ClimateT°/ precipitation
Ground vegetation
Direct & indirect climate effects on tree regeneration
?
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?
Field experiment
Spatio-temporal variation of climatic conditionsSpatio-temporal variation of climatic conditions- 10 sites- 10 sites- 3 years- 3 years
500 m 500 m
1000 m1000 m
2000 m2000 m
QuercusQuercus
FagusFagus - - QuercusQuercus
Fagus-Abies-Fagus-Abies-PiceaPicea
PiceaPicea
PinusPinus
800 800 mm
1400 m1400 m
2000 m2000 m
FagusFagus - - QuercusQuercus
FagusFagus - - AbiesAbies
Fagus-Abies-PiceaFagus-Abies-Picea PiceaPicea
Pinus uncinata Pinus uncinata
1500 m1500 m
2000 m2000 m
Pinus sylvestris Pinus sylvestris
Larix decidua Larix decidua
Pinus uncinata Pinus uncinata
Vercors
Belledonne
Cerces
Field experiment
Spatio-temporal variation of climatic conditionsSpatio-temporal variation of climatic conditions- 10 sites- 10 sites- 3 years- 3 years
Ground vegetation
Can
op
y o
pen
ess g
rad
ien
t
~ 13 000 seedlings
~ 160 000 seeds
Ele
vati
on
8 species : Quercus petraea, Fagus sylvatica, Abies alba, Picea abies, Larix deciduas, Pinus sylvestris, Pinus uncinata & Pinus cembro
Field experiment
NoGround
vegetation
x2
Monitoring of T° & soil water availability on each site
Bioclimatic variables
- Water availability- Water availability- Degree-day sum (>5.54 °C)- Degree-day sum (>5.54 °C)
Correlation => complex climatic Correlation => complex climatic gradientgradient
Seedling survival
Complex plants interactions
ClimateT°/ precipitation Individual based HB regression :
plants interactions coefficients - direct adult tree effect - direct ground vegetation effect - indirect adult tree effect
Coeff
icie
nts
+Facilitation
- Competition
Degree days sum
Direct ground vegetation
Direct adult tree
Indirect adult tree
Results
Low elevation species
High elevation species
Coeff
icie
nts
Direct effect
DDS
Degree days sum
Competition
Direct ground vegetation
Direct adult tree
Indirect adult tree
Results
Coeff
icie
nts
Indirect effect
Low elevation Species
Degree days sum
Indirect facilitation
Direct ground vegetation
Direct adult tree
Indirect adult tree
Results
High elevation Species
Few indirect effect
500 m 500 m
1000 m1000 m
2000 m2000 m
QuercusQuercus
FagusFagus - - QuercusQuercus
Fagus-Abies-Fagus-Abies-PiceaPicea
PiceaPicea
PinusPinus
800 800 mm
1400 m1400 m
2000 m2000 m
FagusFagus - - QuercusQuercus
FagusFagus - - AbiesAbies
Fagus-Abies-PiceaFagus-Abies-Picea PiceaPicea
Pinus uncinata Pinus uncinata
1500 m1500 m
2000 m2000 m
Pinus sylvestris Pinus sylvestris Larix decidua Larix decidua
Pinus uncinata Pinus uncinata
Vercors
Belledonne
Cerces
Insect herbivory field experiment
Leaf herbivory at vegetation peak Leaf herbivory at vegetation peak
% leaf area% leaf area
Degree-day sum
Fagus
Abies
P. uncinata
LarixPicea
P. cembro
Leaf folivory increase with DDS
% f
olivory
Quercus
Lower folivory for high elevation species
Insect herbivory results
Inoculum
Fagus sylvatica
sterilized
500 m 500 m
1000 m1000 m
2000 m2000 m
QuercusQuercus
FagusFagus - - QuercusQuercus
Fagus-Abies-Fagus-Abies-PiceaPicea
PiceaPicea
PinusPinus
Belledonne
Soil biota lab experiment
3 seeds per pots
Seedling survival
Soil biota
Seed
lin
g
su
rviv
al
Elevation
Sterilized
Negative soil biota effect at low elevation
Soil biota results
Seedling
Adult tree
Insects herbivory
Soil µ-organismes
Increasing Degree-day sum
Decreasing Water
Ground vegetation
Negative direct interaction increase
Seedling
Adult tree
Increasing Degree-day sum
Decreasing WaterPositive indirect interaction increase
Ground vegetation