Hardy Griesbauer

Douglas-fir (Pseudotsuga menziesii) is a commercially importantconifer in British Columbia and it is one of the province’s mostgenetically diverse tree species, spanning climatic conditions rangingfrom semi-arid habitats where it is a climax species occurring inuneven aged stands to wet interior rainforests where it is a long-livedseral component in more even-aged stands with a mixture of otherspecies. Characterizing changes in tree population sensitivity toclimate variation across the range of conditions where Douglas firoccurs in B.C. will help to predict their future competitive abilities,productivities, local abundances and geographical transferability. Their sensitivities will likely vary among populations adapted todifferent climates, and population responses may be particularlypronounced at their climatic limits in B.C.’s northern interior.

 To examine the climate sensitivities in interior Douglas-fir across a wide range of climatic conditions, growth responses to inter-annual climate fluctuations are being conducted in about 30-35 mature populations in southern and central B.C. Growth responses are being characterized by standard dendroecological methods. Detrended growth chronologies in each population are being compared to historical variation in key climate variables (generated from local climate data and ClimateBC) to quantify the sensitivity to climate fluctuations within and between Douglas-fir populations. The climate-growth relationships among interior Douglas-fir populations will then be used to generate “responses surfaces” to be applied in the conceptualizations of a landscape model to predict Douglas-fir response to future climate change.