Effects of Environmental Factors on Bird Communities in Different Urbanization Grades: An Empirical Study in Lishui, a Mountainous Area of Eastern China

SIMPLE SUMMARY: In this study, we analyzed the differences in bird diversity in townships with different levels of development to identify the key factors that affect local bird diversity. The results showed that bird diversity increased in moderate urbanization in the mountainous area. At the township scale, bird diversity was determined by the combined effects of landscape diversity and landscape fragmentation. Under the premise of maintaining a high forest coverage rate, increasing landscape diversity and landscape fragmentation is conducive to improving the number, richness, and diversity of bird species. The effect of landscape diversity on bird species numbers, bird richness, and bird diversity is stronger than that of landscape fragmentation. In future urban development planning, heterogeneity and diversity of the landscape pattern can be increased by constructing an urban biological habitat in order to maintain and improve biodiversity. The results obtained in this study provide a practicable reference for formulating biodiversity conservation strategies and constructing reasonable and safe biodiversity patterns. ABSTRACT: The rapid development of urbanization has changed landscape patterns and biological habitats severely and, therefore, affected biodiversity. In this study, we selected 75 townships in Lishui, a mountainous area in eastern China, to conduct bird surveys for two years. We analyzed the birds’ composition characters in townships with different levels of development in order to identify the effects on bird diversity of the urban development level, land cover pattern, landscape pattern, and other factors. In total, 296 bird species from 18 orders and 67 families were recorded between December 2019 and January 2021. A total of 166 species of birds belonged to Passeriformes (56.08%). The seventy-five townships were divided into three grades by K-means cluster analysis. The average number of bird species, richness index, and diversity index were higher in G-H (highest urban development level) compared with the other grades. At the township level, landscape diversity and landscape fragmentation were the key factors that positively affected the bird species number, diversity index, and richness index. Landscape diversity had a greater effect than landscape fragmentation, particularly on the Shannon–Weiner diversity index. The diversity and heterogeneity of urban landscapes could be improved by constructing biological habitats in future urban development planning to maintain and increase biodiversity. The results obtained in this study provide a theoretical basis for urban planning in mountainous areas, and a reference for policymakers to formulate biodiversity conservation strategies, construct reasonable biodiversity patterns, and solve practical biodiversity conservation problems.