Intensive human land uses cause the biotic homogenization of algae and change their assembly process in a major watershed of China

• Published in: The Science of the total environment Vol. 871; p. 162115
• Main Authors: Liu, Yan, Jiang, Xufei, Li, Dianpeng, Shen, Jiachen, An, Shuqing, Leng, Xin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2023
• Subjects: Biodiversity; China; Dispersal limitation; Ecosystem; Functional beta diversity; Humans; Plants; Rivers; Species sorting; Taxonomic beta diversity; China; Functional beta diversity; Taxonomic beta diversity; Species sorting; Dispersal limitation
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.162115

Human land uses are a crucial driver of biodiversity loss in freshwater ecosystems, and most studies have focused on how cities or croplands influence alpha diversity while neglecting the changes in community composition (beta diversity), especially in algae. Here, we examined the taxonomic and functional composition of algae communities and their underlying drivers along the human land-use intensity gradient in the Huai River basin, the third largest basin in China. Our results indicated that the increased intensity of human land use caused biotic homogenization (decreasing compositional dissimilarity between sites) of algae communities in terms of both taxonomic and functional traits. Functional beta diversity was more sensitive to human land uses than taxonomic beta diversity. Furthermore, we found that the increased intensity of human land use altered algae assemblage processes. As opposed to the low- or moderate-intensity human land uses, in high-intensity groups, species sorting rather than dispersal limitations dominated algae community assembly. NO2-N, HCO3, and Fe were the major factors explaining the variance in the taxonomic and functional beta diversities of algae. Human land use reshaped the taxonomic and functional structures of algae, raising concerns about the ecological processes altered by human activity. [Display omitted] •High-intensity land uses cause algae community homogenization.•Response of functional traits to land-use change is more sensitive than taxa.•Only species sorting dominated community assembly in high-intensive land uses.•Moderate-intensive land use does not have significant effect on community composition.•We offered evidence for balance the land use expansion and biotic conservation.