Energy drives multi-faceted diversity patterns of benthic macroinvertebrates in China with important conservation implications

Biodiversity patterns at large scales and their driving mechanisms are central topics in macroecology and biogeography. China is a global biodiversity hotspot and is one of the countries with the richest macroinvertebrate assemblages on Earth. However, national-scale studies on macroinvertebrates diversity and their driving mechanisms are still lacking. Here, we aimed to analyze the spatial patterns of species, functional and phylogenetic α and β diversity by assembling a comprehensive dataset on the distribution of Chinese macroinvertebrates. We also evaluated the explanatory power of three hypotheses, i.e., ‘environmental heterogeneity’, ‘energy’, and ‘dispersal’, in explaining macroinvertebrates diversity patterns. The spatial patterns in China revealed lower species, functional and phylogenetic α diversity of macroinvertebrates in the northwest regions and higher diversity in the southeast, with major biodiversity hotspots concentrated in the Heilongjiang River, middle and lower reaches of Yangtze River, and Pearl River basins. Species, functional and phylogenetic β diversity were higher in the Northwest Inland River, Yellow River, and upper reaches of Yangtze River basins compared to other basins. All diversity facets were best explained by the energy factors with strong unique effects (explaining 84% of the total variation), and the influence of environmental heterogeneity and dispersal-related factor was weak. The Yalong River, upper reach of Min River and headwaters of Yellow River basins were identified as priority protected areas for macroinvertebrates diversity, while threats to biodiversity in the middle and lower reaches of Huai River, Tai Lake, and Qiantang River basins require greater attention. This study provides important information for the conservation and management of biodiversity and freshwater ecosystems both in China and globally. • There are significant spatial patterns in multi-faceted diversity among the nine major river basins of China. • Energy factors play the most important role in explaining the patterns diversity of macroinvertebrates. • Three sub-watersheds are identified as priority protected areas, and three sub-watersheds are identified as key areas of concern for macroinvertebrates diversity, respectively.