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Biased reserve networks alter climate change impacts.
Pyke, Christopher *,1, 1 National Center for Ecological Analysis and Synthesis, Santa Barbara, CA
ABSTRACT- Human activities are altering the geographic distribution of habitat while simultaneously changing climate patterns. This creates dynamic landscapes where species are squeezed into smaller ranges with increasing limitations on available habitat. Biological reserves are set aside to promote species survival; however, reserves are rarely designed explicitly to proportionally represent the full range of environments inhabited by target organisms. Often networks of biological reserves protect only a relatively small, potentially biased sample of regional conditions. This problem may result in counter-intuitive distributions of remaining environmental conditions under combinations of climate and land-use change. This study explored these implications for reserve networks in California. The study combined a broad-scale analysis of climatic conditions available to wildlife across the state with a detailed analysis of changes in hydrologic regimes for vernal pool wetlands in the Central Valley of California. Models of regional climate change and land-use change were combined with geographic data about the distribution of land management to estimate the availability of climatic conditions to species under a series of scenarios for the years 2040 and 2100. The results indicate substantial bias in the distribution of climatic conditions in existing biological reserves for most species. Lands managed for combinations of resource extraction and biodiversity value (so-called working lands) can make up the difference and, in combination with reserves, provide adequate climatic representation. In the Central Valley, climate change alone could shift the distribution of hydrologic conditions toward longer, more frequent periods of inundation. However, existing reserves are biased toward the drier portions of the region and if habitat outside reserves is lost, the surviving wetlands will experience drier conditions even under wetter climate scenarios. These findings indicate that establishing reserve networks that proportionally represent current climate can contribute to a predictable and more manageable response to climate change.
Key words: land-use change, California, climate change, reserves