Abstract
As a clean and green renewable energy source, wind power attracts more and more attention globally, and rapidly expands its use scale. There are conflicts between wind power development and bird protection. The impacts of wind farms on birds is a hot topic for ecologists and conservationists. To estimate the effects of wind turbines on avian species diversity and their functional and phylogenetic diversity, we conducted line transect surveys in January, March, April and May 2019. Thirty-two line transects were divided into four gradients according to the distance from the wind turbines, i.e., 100-300 m (6 transects), 300-500 m (13 transects), 500-700 m (8 transects), >700 m (5 transects). The results showed that a total of 76 resident breeding birds were recorded, belonging to 11 orders and 31 families. Passeriformes and Timaliidae had the highest species richness (53 and 12 species, respectively). Bird species richness, functional richness (FRic), and phylogenetic diversity (Faith's PD) were increased with increasing distance from the wind turbines. Specifically, bird richness, FRic and phylogenetic diversity increased little within 500 m of the wind turbines, whereas a significant increase occurred over 500 m from wind turbines. The community-weighted mean of dispersal ability showed an increasing trend with distance from the wind turbines. The standardized effect size of both mean pairwise functional/phylogenetic distance (SES.MFD and SES.MPD) were less than 0 in all transects, with about half of which being significantly lower than expected at random. This finding suggested that the impacts of wind farms on bird species, functional and phylogenetic diversity occurred within 500 meters from wind turbines, with a pattern of functional and phylogenetic clustering. The impacts of wind turbines on birds were multi-dimensional. It is therefore difficult to provide complete perspective on assessing the impacts of wind farms on birds when only considering species diversity.