Turnover structures in macrobenthic communities rather than nestedness in the Yellow River Delta wetland, China

Comprehending the triggers, such as turnover and nestedness, in structuring of macrobenthic communities is crucial for informing wetland biodiversity conservation strategies. Previous studies on macrobenthic communities in the Yellow River Delta wetland lacked beta-diversity analysis and did not consider the role of turnover and nestedness in different ecological zones. Therefore, we analyzed taxonomic, phylogenetic and functional alpha- and beta-diversities in the Yellow River Delta wetland, intertidal and offshore zones. The study revealed that the intertidal zone had higher polychaete abundance of species, while the offshore zone was dominated by a more mobile crustaceans and fish species. The findings of this study showed that alpha-diversity metrics for taxonomic, phylogenetic and functional dimensions were higher in offshore stations, whereas beta-diversity was higher in intertidal communities. Turnover contributed more significantly to taxonomic, phylogenetic and functional beta-diversities, highlighting changes not only happened in species composition but also in phylogenetic relationships and functional traits between the two zones. Additionally, the intertidal zone exhibited higher turnover, while the offshore zone had an increased proportion of nestedness component contribution, especially for functional beta-diversity. Correlation analysis indicated significant associations among three beta-diversities and their respective turnover and nestedness components. The correlation between taxonomic and phylogenetic aspects was stronger compared to the correlations between taxonomic and functional aspects as well as between functional and phylogenetic aspects. These findings enhance our understanding of the drivers of biodiversity in macrobenthic communities and underscore the importance of considering phylogenetic and functional dimensions in beta-diversity studies.