Modelling conifer species distributions in mountain forests of the Pacific Northwest


McKenzie, D., Peterson, D.W., Peterson, D.L. 2003. Modelling conifer species distributions in mountain forests of the Pacific Northwest. Forestry Chronicle 79:253-258.


Understanding the effects of climatic change on mountain forests, where snowpacks and short growing seasons limit tree establishment and growth, is a key concern for both ecologists and foresters. We quantified associations between climatic and biophysical variables and individual conifer species distributions in mountain forests with generalized linear models. For the majority of species, a unimodal response to moisture and temperature gradients was evident, suggesting that an environmental niche can be identified. Species known to respond to limiting factors in the abiotic environment showed the strongest associations with predictor variables. The models can improve forecasts of the potential redistribution of species on the landscape in response to climatic change, but disturbance, migration rates, and limits on regeneration are important sources of uncertainty. Nevertheless, by identifying climate-based niches of different species, we can identify effective strategies for reforestation and alert managers to particularly sensitive or vulnerable ecosystems and landscapes.