Aim: Although assembly processes have been studied in a wide range of taxa, determining assembly rules remains controversial, particularly in assemblages consisted of species with strong dispersal capacities. Moreover, few studies focused on communities in recently human‐created habitats. We tested two prevailing but opposing hypotheses, environmental filtering and limiting similarity, in waterbird communities across subsidence wetlands created by underground coal mining in China, with an aim to better understand assembly processes in communities composed of highly mobile species in human‐dominated landscape.Location: The North China Plain.Methods: We quantified taxonomic, functional and phylogenetic diversity of the waterbird assemblages in different seasons and compared the mean pairwise distances (MPD) and the mean nearest taxon distances (MNTD) with null models to examine whether co‐occurring species were clustered or overdispersed on the functional dendrogram or phylogenetic tree. Independent contributions of multi‐scale habitat variables therein were determined using a hierarchical partitioning method.Results: We showed asynchronous patterns of seasonal dynamics among the multiple diversity metrics, with highest species diversity during autumn migration. Generally, the co‐occurring species were functionally and phylogenetically clustered. Habitat variables had stronger effects on the functional structure than on the phylogenetic structure of the communities. The degree of functional clustering increased in older and larger wetlands, while the assemblages shifted from functional clustering to overdispersion with increasing habitat diversity, landscape connectivity and human disturbance.Main conclusions: The waterbird assemblages were mainly structured by environmental filtering, and the assembly processes were significantly affected by habitat variables, with stronger effects on functional diversity. Our study highlights the importance of environmental filtering and habitat variables in structuring assemblages dominated by species with high dispersal capacities and suggests that increasing habitat diversity and reducing disturbances will contribute to waterbird conservation in this human‐dominated landscape.

University campuses are important components of cities, harboring the majority of urban biodiversity. In this study, based on monthly bird survey data covering 12 university campuses located either downtown or in the newly developed areas in Nanjing, China, in 2019, we studied the assembly processes of each campus’s bird population and their main drivers by modeling a set of ecological and landscape determinants. Our results showed that (1) bird abundance and species diversity in the newly developed areas were significantly higher than in those downtown; (2) the phylogeny of bird communities in all universities followed a pattern of aggregation, indicating that environmental filtering played a major role in community assembly; (3) specifically, grass, water, and buildings were the main factors affecting each campus’s bird community’s functional and phylogenetic diversity, with the areas of grass and water habitats having a significant positive correlation with phylogenetic diversity, while the size of building areas was negatively correlated. Our results emphasize that habitat features play a decisive role in determining urban bird population diversity and community assembly processes. We suggest that increasing landscape diversity, e.g., by reasonably arranging the location and area of water bodies and grasslands and improving the landscape connectivity, could be a powerful way to maintain and promote urban bird diversity.

Landscape changes due to urban expansion may severely influence urban biodiversity through direct and indirect effects. Hence, a comprehensive understanding of the urban expansion effects on species diversity is essential for conservation biologists, urban planners, and policymakers to help design more practical and effective conservation strategies. Here, based on monthly bird survey data of 12 university campuses distributed in the center and the Xianlin university town of Nanjing city, we first compared the differences of the campuses bird species richness, Shannon-Wiener, and Simpson indices. Then, we analyzed the effects of a variety of landscape attributes on the campuses bird species richness. Unlike other studies, we also constructed a 2 km buffer area surrounding each campus and analyzed the effects of the landscape attributes of the buffer area on species richness. We found that bird species richness was higher in the campus of Xianlin compared to those in the center. Landscape attributes played an important role on bird species richness, especially for the determinants in the buffer area. Specifically, species richness, Shannon-Wiener, and Simpson indices increased with the increasing area of water and green space both within the campus and the buffer area. Not surprisingly, bird species richness and diversity were more affected by fragmentation of the buffer area, increasing with the aggregation index and decreasing with the splitting index. Our study emphasized that landscape attributes of both campuses and buffer areas determined bird species richness and diversity, offering several practical implications for urban biodiversity maintenance and eco-friendly urban planning.