Environmental factors affecting the composition and diversity of avian community in mid- to late breeding season in urban parks and green spaces

Abstract

The importance of biodiversity in urban parks and green spaces has been increasingly emphasized. In this study, we focused on the avian community in urban parks and green spaces and aimed to elucidate its characteristics and affecting factors. Specific questions addressed are, (1) What ecological traits feature the avian communities in urban parks and green spaces? (2) What environmental factors are important in changing the structure or avian communities in urban area, such as species diversity and guild structure. The study sites were 20 urban parks or green spaces located in central urban area in Sendai, northern Japan. Bird surveys were conducted from middle to late breeding season. We measured environmental factors of stand and landscape level, including water related environment. The overall species number decreased in highly urbanized area, while diversity index ( H′) increased, probably because the species with low frequency did not occur in urban environment and increased equitability of the community. The result of CCA revealed that the characteristics of avian communities in Sendai City were determined by the prevalence of water-related environments and the predominance level of urban environment. Insectivores and foliage foraging species contributed to increasing overall species number, while ground foraging species negatively affected to the overall avian diversity of a community. These findings suggested that increased shrub in stand level was effective to increase the overall species number, and to be considered future design of the city parks.