1. Comparison of sensitivity of landscape- fire-succession models to variation in terrain, fuel pattern and climate GCTE Task 2.2.2 Relationships between Global Change and Fire Effects at Landscape Scales

2. Contributors Geoff CaryAustralian National University Robert KeaneUSDA Forest Service Robert GardnerAppalachian Laboratory, U. Maryland Sandra LavorelUniversité Joseph Fourier, France Mike FlanniganCanadian Forest Service Ian DaviesAustralian National University Chao LiCanadian Forest Service Jim LenihanUSDA Forest Service Scott RuppUniversity of Alaska Florent MouillotCarnegie Inst. of Washington, Stanford

3. Context Interactions between fire, climate and vegetation strongly influence landscape dynamics Simulation models are a critical tool for understanding these dynamics There has never been a uniform comparison that objectively evaluates model behaviour

4. Context Inherent difficulties in comparing models that were developed for a variety of purposes: Difficulty in obtaining validation data Difficulty in removing bias from the context in which the model was originally developed

5. Approach Unique approach to resolving these difficulties Standardise the variation in terrain, fuel pattern and climate Compare the sensitivity of model output to variation in terrain, fuel pattern and climate (i.e. not validation)

6. Models and native landscapes EMBYRYellowstone NP FIRESCAPESouth-east Australia LAMOS-DSGeneric (Corsica) LANDSUMNorth-west US SEM-LANDWest-central Alberta

7. Models and native landscapes Lattice models Link fire ignition, fire spread, succession and fire effects Large landscapes, long duration Represent a variation in LFSM formulation

8. Experimental design TreatmentLevelsReplicates Terrain Flat1 map/level Rolling Mountainous Fuel clumping Fine10 maps/level Coarse Climate Observed10 single years Warmer & wetter /level Warmer & Drier

9. Terrain Valley Mid slope Peak 50 km Elevation range Flat 1250 m Rolling 625 – 1875 m Mts 0 – 2500 m Landscape position

10. Fuel clumping Low Moderate High 50 km Fine 25 ha clumps Fuel loads Coarse 625 ha clumps

11. Weather – Glacier National Park

12. Climate scenarios Temperature Precipitation Warmer / Wetter + 3.6 o C x 1.2 Warmer/ + 3.6 o C x 0.8 Drier

13. Replication and simulations Terrain (3 levels)1 map / level Fuel clumping(2 levels)10 maps / level Climate (3 levels)10 single years / level 3 x 2 x 10 x 3 x 10 = 1800 single year simulations / model Fires affected fuel load/age Vegetation succession “removed”

14. Analysis Sensitivity of ln (area burned) to Terrain Fuel pattern Climate change Inter-annual variation in climate … and their interactions Variance in area burned explained (r 2 ) by factors and interactions amongst them determined from fully factorial GLM (SAS)

15. Results Variation in climate explained considerable total variance for some models Model Weather replicate r 2 EMBYR 0.33 * FIRESCAPE 0.09 * LAMOS-DS 0.04 * LANDSUM 0.33 * SEM-LAND 0.54 *

16. Climate Climate change explained considerable total variance in area burned for most models Model Climate r 2 Effect EMBYR 0.03 * (0.04)WW < WD = OB FIRESCAPE 0.42 * (0.46) OB < WW = WD LAMOS-DS 0.28 * (0.29) OB < WW = WD LANDSUM 0.18 * (0.27) OB < WW < WD SEM-LAND 0.37 * (0.81) OB < WW < WD

17. Fuel Fuel explained considerable total variance in area burned for EMBYR Model Fuel r 2 Effect EMBYR 0.21 * (0.32)Fine < Coarse FIRESCAPE 0.02 * Fine < Coarse LAMOS-DS 0.00 LANDSUM 0.00 * Fine < Coarse SEM-LAND 0.01

18. Terrain Terrain explained considerable total variance in area burned for FIRESCAPE Model Terrain r 2 Effect EMBYR 0.00 FIRESCAPE 0.29 * (0.32) Flat < Rolling < Mountainous LAMOS-DS 0.00 LANDSUM 0.00 SEM-LAND 0.00

19. Summary SourceNo. models where: r 2 > 5% Pr > F (0.001) Terrain 11 Fuel 14 Terrain * fuel Weather replicate 45 Terrain * weather replicate Fuel * weather replicate Terrain * fuel * weather replicate Climate 45 Terrain * climate Fuel * climate Terrain * fuel * climate Climate * weather replicate 35 Terrain * climate * weather replicate Fuel * climate * weather replicate Terrain * fuel * climate * weather replicate

20. Conclusion Models largely sensitive to annual variability in weather Important to understand changes in climate variability Importance might diminish with particular changes in climate

21. Conclusion Models generally more sensitive to climate than fuel pattern or terrain Warmer/wetter and warmer/drier climates result in significant increases in area burned More important to understand climate trends and annual variability in weather, than fuel pattern or terrain, in explaining variation in area burned at the landscape scale

22. Conclusion Individual models sensitive to fuel pattern and weather because key processes represented in them.