Do Newly Built Urban Parks Support Higher Bird Diversity? Evidence from the High-Density Urban Built-Up Area of Zhengzhou, China

Rapid urbanization has resulted in widespread habitat loss and fragmentation, threatening global biodiversity. Urban parks serve as essential refuges for wildlife within cities, particularly for birds, which are sensitive indicators of ecosystem health and habitat quality. In recent years, numerous Chinese cities have begun integrating biodiversity-friendly design approaches into new park development. However, the effectiveness of these strategies remains insufficiently evaluated. This study assesses the ecological performance of newly built parks by examining 11 recently constructed parks (within the past decade) and 9 historical parks in Zhengzhou, China’s high-density urban area. Monthly bird surveys were conducted across all 20 parks from May to December 2020, covering breeding, post-breeding, and overwintering seasons. Our findings reveal that new parks significantly outperformed old parks in bird abundance, species richness, Shannon diversity index, and functional diversity. Analysis of environmental variables at both local (within-park) and landscape (1-km buffer) scales showed that habitat diversity and multi-layered vegetation structure were the most influential local factors promoting bird diversity, while green space connectivity was the primary landscape-scale contributor. Notably, neither park area nor age significantly predicted diversity patterns. Based on these results, we propose three key planning strategies: (1) enhancing habitat diversity within parks to support species from various ecological niches; (2) implementing multi-layered vegetation planting to provide diverse food resources and nesting opportunities; (3) improving green space connectivity to facilitate species movement and population persistence within urban environments. These findings provide valuable insights for designing more effective biodiversity-friendly urban green spaces.