Persistence of Wildlife Populations in Low-Diversity Renewable Wind-Energy Landscapes

Abstract

The global benefits of increased renewable energy production can come at a cost to local biotic communities and even regional ecosystems. For example, wind energy developments kill birds and bats, and fragment habitat for terrestrial vertebrates within developed project areas. If sensitive species are extirpated, patterns of biotic interactions may be altered at wind farms. In this study, I assessed whether wind energy developments produced other significant ecological costs. Specifically, I determined whether wind farms reduced community diversity and affected the persistence of wildlife populations. I examined this question first by comparing richness, abundance, and diversity of species and communities at wind farm sites, relative to similar reference sites in the San Gorgonio Pass of Southern California. Secondly, I used a focused demographic study of side-blotched lizards, Uta stansburiana, to identify whether altered wind farm habitats still supported viable populations of common terrestrial vertebrates. I found that wind farms, when compared to study areas without wind turbines, were often noisier and more disturbed, with less diverse communities of plant and predators. On wind farms, the probability of endemic plant presence declined, while presence of non-native plants increased. For populations of U. stansburiana, I found no differences in demographic parameters between wind farm and non-wind farm sites, suggesting that wind farms may be viable wildlife habitats for common terrestrial prey species. While some differences in community composition and diversity were evident, I noted that wind farms were able to support many of the same species found in nearby natural areas. And yet, wind energy technology was associated with local declines in diversity, which may affect the sustainability of this technology in local ecosystems.