1. Predicting current and future tree diversity in the Pacific Northwest I R S S Richard Waring 1 & Nicholas Coops 2 1 Oregon State University 2 University of British Columbia Richard Waring 1 & Nicholas Coops 2 1 Oregon State University 2 University of British Columbia

2. Process-based Model of GPP & NPP Environmental Modifiers VPD Soil Water Tmin Frost Quantum / Radiation Use Efficiency x PAR x  PAR Rainfall GPP & NPP Additional 3-PGS Modifiers

3. Environmental constraints on photosynthesis for Douglas-fir in the Pacific NW, U.S.A. soil water evaporative demand suboptimal temperature Frost limitations

4. Current environmental constraints on photosynthesis for Douglas-fir in British Columbia, Canada Soil drought Evaporative demand (D) Suboptimal temperature Frost frequency

5. Species differences in sensitivity to environment soil drought evaporative demand Suboptimal temperaturefrost sensitivity

6. Different adaptations sort environmental distributions of NW tree species Common namescientific nameenvironmental adaptations Sitka sprucePicea sitchensis (Bong.) Carrmost sensitive to humidity deficits & temperature extremes ponderosa pinePinus ponderosa Dougl. ex Loud.more adapted to drought, frost, and humidity deficits than Douglas-fir western juniperJuniperus occidentalis Hook.most adapted to drought and high VPD lodgepole pinePinus cortorta Dougl. ex Loud.most tolerance of frost Douglas -firPseudotsuga menziesii (Mirb.) Franco adapted to intermediate environmental conditions western hemlockTsuga heterorphylla (Raf.) Sarg.more sensitive to humidity deficits and to drought than Douglas-fir

7. Defining different species environmental tolerances in reference to Douglas-fir Sitka spruce lodgepole pine Ponderosa pine Frost tolerant Drought tolerant Drought adverse

8. 3737 USDA Forest Service Forest Inventory & Analysis Plots

9. Current range predictions (left) vs. FIA plots data(right) of western hemlock(upper) and Sitka spruce (lower )

10. Current Range Predictions (left) and FIA plot locations (right) for ponderosa pine (upper) and lodgepole pine (lower)

11. Reported range of lodgepole pine in B.C. Little’s range map Present on field plots

12. Model predicts progressive reduction in range of lodgepole pine with environment favoring other species in BC 2020 2050 2080

13. Summary Process-based models weight environment limitations as they affect photosynthesis and growth Approach simplified by relating to most widely distributed species Decision trees analysis automatically defines environmental thresholds for different species Predictions of present range good, and potential to predict future ranges, taking into account competition with other species.