Modeling Contemporary Climate Profiles and Predicting their Response to Global Warming for Several Western Forest Species with Small Geographic Distributions
Authored By: M. V. Warwell, G. E. Rehfeldt, N. L. Crookston
Marcus V. Warwell, Gerald E. Rehfeldt, and Nicolas L. Crookston
USDA Forest Service Rocky Mountain Research Station
The Random Forests multiple regression tree was used to develop an empirically-based bioclimatic model for the U.S. distribution of Pinus leiophylla. Independent variables included 35 simple expressions of temperature and precipitation and their interactions. These climate variables were derived from a spline climate model for western U.S. that provides point estimates (latitude, longitude, and altitude) at a 1 km2 resolution. Analyses used presence-absence data from about 2245 permanent sample plots largely from FIA. Errors of classification for analyses of the occurrence of P. leiophylla were 0.1% for omission and 11% for commission. The mapped predictions of species occurrence using the species’ climate profile were more accurate than published range maps. The Hadley and Canadian general circulation models (GCMs) were then used to assess the response of the species contemporary climate profile to climate change. Results indicate little change in the total area occupied by the species’ island like distribution throughout the century. However, the species’ climate profile is projected to move 500km north to Colorado and upward in altitude 500m. No portion of its current range would retain a climate suitable for the species’ U.S. populations by the end of the century. In addition to analysis of P. leiophylla, this paper will also present results for bioclimatic models of several western species with small distributions which may predispose them to a greater threat from climate change. These models can be used to assess species suitability for a specific location (latitude, longitude and altitude) based on either contemporary or projected climates. The application of these modes as functional tool that managers can use to mitigate effects of climate change will be addressed.
Biodiversity Session - Thursday Afternoon
corresponding author:
Marcus V. Warwell
USDA Forest Service
Rocky Mountain Research Station
1221 S. Main
Moscow, ID 83843
208-883-2322
mwarwell@fs.fed.us
