This study uses a spatially explicit forest simulation model to assess the impact of climate change on ecosystem goods and services in mountain forests in Valais, Switzerland. The model projects increases in forest biomass at high elevations but decreases at low elevations, along with a shift to more drought-tolerant species at low elevations. Biodiversity is projected to increase at the landscape scale but decrease at low elevations and increase at middle and high elevations. Protection from rockfall is projected to decrease at the landscape scale in a non-monotonic way, decreasing at low and intermediate elevations but increasing at higher elevations. Changes in biodiversity and rockfall protection are generally positively correlated at the landscape scale but correlations vary over time

1. Assessing the impact of climate change
on the spatial distribution of multiple
ecosystem goods and services in
mountain forests.
Ché Elkin
Harald Bugmann
che.elkin@env.ethz.ch

2. Forest dynamics…..
… and climate change impacts
EGS
• Biodiversity
• Protection
(gravitational hazards)
• Forest harvest

3. Forest dynamics…..
… and climate change impacts
EGS
•Biodiversity
• Protection Spatial correlations?
(gravitational hazards) Changes through time?
• Forest harvest

4. Landclim: forest simulation model
Wind throw
Fire
Disease
• Spatially explicit (25 x 25 m cells) Harvest
• Dynamic, process based
• Modeling of succession
• Cohort based
• Dynamics of tree cohorts:
establishment, growth, mortality

5. Assessing the current and future
state of forest ecosystem goods
Visp
25 m
Species Cohort Biomass Stem #
(tones/ha)
Picea abies 1960 3.474 4
Picea abies 1995 0.011 12
Pinus cembra 1994 0.010 11
Abies alba 1982 0.020 2
Abies alba 1983 0.018 1
EGS
•Biodiversity
• Protection
• Forest Harvest

6. Case study: Valais, Switzerland
Visp
Climate scenario
IPCC 4: a1b
future climate
(2100)
current climate

7. Forest state: Forest biomass (tons /625m2)
Forest biomass
2000 2050 2100
Visp

8. Changes in species composition
Forest state through time (2000 – 2200)
Biomass
Biomass

9. EGS Dynamics
• Biodiversity
• Protection from gravitational hazards
• How do EGS response through time to
climate drivers ?
• How do EGS respond spatial to climate
drivers ?
• Where are EGS correlated?
• When are EGS correlated?

10. EGS changes
Biodiversity
Structural Shannon’s index
Protection against
gravitational hazards
Rock fall
2000 2050 2100

11. Shannon’s Structural Index
2010 2020 2030 2040 2050
2000 State
2060 2070 2080 2090 2100
2010 2050 2100

12. Rock fall protection
2010 2020 2030 2040 2050
State 2000
2060 2070 2080 2090 2100
2010 2050 2100

13. EGS correlations: transition
Biodiversity Rock fall
Transition correlation
• Changes in EGS through
time
• Assessment of drivers of
EGS change
2100 2100

14. EGS correlations
Correlations in EGS transitions
• Value normalized based on year 2000 maximum (landscape)
∆x = Xfuture – X2000
∆x > 0.15 2 Strong gain
0.05 < ∆x < 0.15 1 Weak gain
-0.05 < ∆x < 0.05 0 No change
-0.15 < ∆x < -0.05 -1 Weak loss
∆x < -0.15 -2 Strong loss

15. EGS Correlations: Transition
EGS correlation Positive correlations only
2001 2050 2100
2100
- 4 Negative correlation - 4 both EGS weaken
+ 4 Positive correlation + 4 both EGS strengthen

16. EGS Correlations: Transition
EGS correlation Negative correlations only
2001 2050 2100
2100
- 4 Negative correlation + 4 Rock fall strengthens, Biodiversity weakens
+ 4 Positive correlation - 4 Biodiversity strengthens, Rock fall weakens

17. Conclusions
Forest state
• low elevations: decrease in biomass, shift towards drought
tolerant species
• high elevations: increase biomass
Biodiversity
• increase at landscape scale
• decrease at low elevations, increase at middle/ high elevation
Rock fall
• decrease at landscape scale (not monotonic)
• decrease at low and intermediate elevations, but increase at
higher elevations

18. Conclusions
EGS correlations
Climate driven changes in rock fall and biodiversity are
generally positively correlated (at the landscape scale)
Positive correlations
• Low elevations: both decrease
• very High elevations: both increase
Negative correlations
• Time dependent (less spatial consistency)
• 2050 : rock fall strengthens , biodiversity weakens
• 2100: biodiversity strengthens, rock fall weakens

19. che.elkin@env.ethz.ch