Aim: Core-satellite wetland networks are widespread worldwide, and exploring how biotic assemblages change over these networks can offer important implications for biodiversity conservation of these systems. We aimed to detect the spatial distribution patterns and assembly processes of waterbird communities within the wetland networks.

Location: The core wetland (Shengjin Lake located in the middle and lower reaches of the Yangtze River floodplain, China) and its surrounding satellite wetlands, i.e., reservoirs, aquaculture ponds, paddy fields and natural ponds.

Methods: We calculated and decomposed multi-faceted pairwise β-diversity (taxonomic, functional and phylogenetic) of waterbird assemblages within each type of satellite wetland and within counting points of the core wetland. The observed functional and phylogenetic β-diversity were compared with simulated means generated by null models. We also quantified community dissimilarities between satellite wetlands with Shengjin Lake, and tested whether the contribution of different satellite wetlands to regional β-diversity differed.

Results: Overall, taxonomic β-diversity and turnover were lower during summer, and all dimensions of these biodiversity metrics were lower in aquaculture ponds and Shengjin Lake. For most wetland types, taxonomic and phylogenetic β-diversity were primarily contributed by turnover, but nestedness dominated functional β-diversity. All dimensions of β-diversity and nestedness components increased with difference in wetland area. The observed functional and phylogenetic β-diversity did not deviate largely from null expectations during all seasons, indicating the dominance of neutral processes in the community assembly. Aquaculture ponds were more similar to Shengjin Lake in species compositions, functional strategies, and evolutionary relatedness during autumn and winter. Reservoirs and paddy fields generally contributed more to regional β-diversity of all three metrics.

Main conclusions: This study quantified how and why the spatial heterogeneity of waterbird communities differed across this wetland network, providing important implications for management and conservation of waterbirds and their habitats in core-satellite wetland networks.