Green infrastructures and ecological corridors shape avian biodiversity in a small French city

摘要

In the context of increasing urbanization, preserving urban biodiversity has become a priority because biodiversity appears to be a key element when evaluating the well-being of urban residents. Recently, urban management has relied on a 'renaturing' strategy to improve biodiversity, but the benefits of these policies remain debated. In this study, we evaluated the effects of urban land use and green corridors on (1) urban avian biodiversity, and (2) the presence of the most common (top 70%) and least common (bottom 30%) bird species. We surveyed bird diversity at 102 sites during the Spring in a small French city, and performed a PCA on several habitat structures (e.g. roads, houses, grassy areas) to determine the level of urbanization of each site. Then, we tested with GLMMs the effects of land use (PC1), distance to the edge of the city, and distance to the corridor on bird diversity. We found a positive effect of green infrastructures on bird species richness, and this effect was reinforced by the proximity to the green corridor. Thus, bird species richness and the presence of common species were positively impacted by the presence of green areas, the proximity to the city edge and the proximity to the green corridor. The presence of the green corridor contributed significantly to the presence of rare species, which emphasizes its role in promoting avian biodiversity. Green corridors are a key element of the urban landscape because they allow less common species to colonize cities, and thus enhance urban biodiversity.