Long-term wetland biomonitoring highlights the differential impact of land use on macroinvertebrate diversity in Dongting Lake in China

Freshwater wetlands have experienced disproportionate biodiversity loss due to environmental change. The lack of long-term biological data limits our understanding of wetland biodiversity dynamics and principal drivers. Here, we combine aquatic biomonitoring with satellite-derived imagery and spatial-explicit analysis to assess the changes in macroinvertebrate diversity and driving factors from 1988 to 2017 in Dongting Lake, China. The results revealed declining macroinvertebrate alpha diversity (species richness and functional redundancy) but increased beta diversity (taxonomic and functional dissimilarity). An increase in nutrients due to changes in land-use intensity in the surrounding terrestrial ecosystem was the primary mechanism for the losses of species and functional groups. Alpha diversity changes were most influenced by land-use changes in adjacent land areas 1.5 kilometers from the sampling sites, while beta diversity was affected within 50 meters. Our results highlight a need for attenuating land-use effects by establishing protected buffer areas to protect biodiversity in the future.