Abstract

Biodiversity is declining worldwide, and this trend could potentially become more severe as climate conditions change. An integral component of proactive adaptive management planning requires forecasts of how changes in climate will affect individual species. This need has been identified my multiple federal agencies, including the U.S. Fish and Wildlife Service, National Park Service, Bureau of Land Management, and U.S. Forest Service.

 

The goal of this project was to assist land and wildlife managers in anticipating which species are most vulnerable to changes in climate in the Southwest, and how resources can best be invested to facilitate adaptation. Researchers evaluated the current and future breeding ranges of 15 bird and 16 reptile species in the western U.S. using a new approach that models variables such as temperature and precipitation, terrain ruggedness and soil type, and plants that are commonly associated with each species.

 

Results showed that two-thirds of the species examined could be expected to experience a decrease in range, while one-third could experience an increase. Climate variables were found to play a bigger role than landscape or plant variables in determining changes in species range. Researchers also found that as available habitat patches for birds and reptiles become more isolated, their ranges also contract. This finding suggests that strategic management actions focused on conserving and restoring connections between habitat patches could help lessen the severity of the projected range contractions.