Impacts of land-use intensity and land-use diversity on benthic macroinvertebrates assemblages in the Yangtze River basin, China

Global biodiversity is declining, with changes in land use identified as a primary driver-particularly shifts in land-use intensity and diversity within riparian zones. Urbanization and agricultural expansion have increased land-use intensity (LUI), leading to water quality deterioration and changes in aquatic environmental factors, which in turn impair the diversity of benthic macroinvertebrates. Increased land-use diversity (LUD) can provide a variety of habitats for benthic organisms in riparian zones, thereby enhancing the diversity of benthic macroinvertebrates. In this study, we investigated the taxonomic, functional, and phylogenetic diversity of benthic macroinvertebrates to evaluate their correlations with LUI and LUD in macroinvertebrate assemblages of the Yangtze River-the largest river in China. Results from the 2022–2023 field investigation showed that, within the 100–1000 m buffer zone: (1) Increased LUI significantly enhanced α -diversity (e.g., species richness) of benthic macroinvertebrates across all buffer widths, but exerted a significant negative effect on β -diversity; (2) Increased LUD showed no significant effect on α -diversity at any buffer width, but had a significant positive effect on β -diversity (except for the 100 m buffer zone); (3) The effects of LUI and LUD exhibited scale-dependent characteristics. For instance, widening the buffer zone weakened the positive effect of LUI on α -diversity. We further identified that LUI and LUD affected benthic macroinvertebrate diversity through key water quality parameters. These findings highlight that land use has left a profound imprint on river ecosystems. Therefore, it is critical to fully understand the impacts of LUI and LUD on large river ecosystems. • Land use intensity and diversity significantly changed benthic macroinvertebratese diversity in the Yangtze River Basin. • The effects of land use intensity and diversity on benthic macroinvertebrate diversity vary with buffer zone width. • Land use intensity and diversity can indirectly affect the benthic macroinvertebrate diversity by impacts water quality.