School of Life Science and Institute of Wetland Ecology, Nanjing University, Nanjing, 210000, China.
School of Life Science and Institute of Wetland Ecology, Nanjing University, Nanjing, 210000, China.
Sci Total Environ. 2023 May 1;871:162115. doi: 10.1016/j.scitotenv.2023.162115. Epub 2023 Feb 9.
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.
人类土地利用是淡水生态系统生物多样性丧失的关键驱动因素，大多数研究都集中在城市或耕地如何影响α多样性，而忽略了群落组成（β多样性）的变化，特别是藻类。在这里，我们沿着中国第三大流域淮河的人类土地利用强度梯度，检查了藻类群落的分类和功能组成及其潜在驱动因素。我们的结果表明，人类土地利用强度的增加导致藻类群落在分类和功能特征上的生物同质性（站点间组成差异的减少）。功能β多样性比分类β多样性对人类土地利用更敏感。此外，我们发现，人类土地利用强度的增加改变了藻类组合过程。与低强度或中等强度的人类土地利用相比，在高强度组中，物种分选而非扩散限制主导着藻类群落的组装。NO2-N、HCO3 和 Fe 是解释藻类分类和功能β多样性差异的主要因素。人类土地利用重塑了藻类的分类和功能结构，引起了对人类活动改变的生态过程的关注。
