Predicting the occurrence, vulnerability and future distribution of major tree species in the Pacific Northwest in response to climatic change

Nicholas C Coops, Univ, British Columbia, nicholas.coops@ubc.ca (Presenter)
Richard H. Waring, Oregon State University, richard.waring@oregonstate.edu (Presenter)

In the Pacific Northwestern (PNW) region of North America, climatic conditions have significantly warmed since a predominantly cool period between 1950 and 1975. To assess the implications of this shift in climate, we first mapped monthly climatic data from 1950 – 2005 at 1 km resolution across the region and then translated the resulting seasonal climatic variation as it affected photosynthesis and growth of Douglas-fir (Pseudotsuga menziesii) using a process-based growth model (3-PG). Next, we used automated decision-tree analyses to predict the distribution of different coniferous species by creating a suite of rules associated with the relative constraints that seasonal drought, atmospheric humidity deficits, suboptimal and subfreezing temperatures imposed on the growth of Douglas-fir. The resulting models agreed well (r2 average = 0.82) with both presence and absence data recorded for 15 coniferous species on 22,771 field survey plots.

To assess the effect of changes in climatic conditions, the decision-tree models were run annually for each species for the period between 1976 and 2005 to define areas that: (1) remained within or (2) fell outside the mean range of climatic conditions during the earlier cool period for more than half of the years. Based on these criteria, 70% of the 15 native species of conifers analyzed remained suitably adapted within their original ranges, while 30% were deemed vulnerable. Some species showed potential for range expansion of up to 50%, while others were predicted to show major constrict ions. We used the approach to predict the likelihood of major disturbance since 2000 across forested areas in 25 recognized ecoregions (EPA Level III classification) and found good agreement ( r2 = 0.65) with disturbance recorded between 2005-2009 with the MODIS Disturbance Index. The analysis was extended through the rest of the 21st century using climatic projections from the Canadian global circulation model.

Presentation: 2011_Poster_Coops_147_297.pdf (2041k)

Presentation Type:  Poster

Session:  Global Change Impact & Vulnerability   (Tue 11:30 AM)

Associated Project(s): 

• Waring, Richard: Predicting current and future outbreaks of insect and disease attacks on native tree species in the Pacific Northwest with a physiologically-based model ...details

Poster Location ID: 147