Division of Plant and Soil Sciences, West Virginia University, 4100 Agricultural Sciences Building PO Box 6108, Morgantown, WV, 26506-6108, USA.
Institute of Water Security and Science, West Virginia University, 4121 Agricultural Sciences Building PO Box 6108, Morgantown, WV, 26506-6108, USA.
FEMS Microbiol Ecol. 2021 Jan 26;97(2). doi: 10.1093/femsec/fiaa256.
Freshwater ecosystems are susceptible to biodiversity losses due to land conversion. This is particularly true for the conversion of land from forests for agriculture and urban development. Freshwater sediments harbor microorganisms that provide vital ecosystem services. In dynamic habitats like freshwater sediments, microbial communities can be shaped by many processes, although the relative contributions of environmental factors to microbial community dynamics remain unclear. Given the future projected increase in land use change, it is important to ascertain how associated changes in stream physico-chemistry will influence sediment microbiomes. Here, we characterized stream chemistry and sediment bacterial community composition along a mixed land-use gradient in West Virginia, USA across one growing season. Sediment bacterial community richness was unaffected by increasing anthropogenic land use, though microbial communities were compositionally distinct across sites. Community threshold analysis revealed greater community resilience to agricultural land use than urban land use. Further, predicted metagenomes suggest differences in potential microbial function across changes in land use. The results of this study suggest that low levels of urban land use change can alter sediment bacterial community composition and predicted functional capacity in a mixed-use watershed, which could impact stream ecosystem services in the face of global land use change.
淡水生态系统容易因土地转换而导致生物多样性丧失。特别是将土地从森林转换为农业和城市发展用地时，这种情况更为明显。淡水沉积物中蕴藏着提供重要生态系统服务的微生物。在淡水沉积物等动态生境中，微生物群落可能受到许多过程的影响，但环境因素对微生物群落动态的相对贡献仍不清楚。鉴于未来预计土地利用变化的增加，确定相关的溪流理化性质变化将如何影响沉积物微生物组是很重要的。在这里，我们在美国西弗吉尼亚州的一个混合土地利用梯度上，对一个生长季节的溪流化学和沉积物细菌群落组成进行了描述。尽管各地点的微生物群落组成存在差异，但沉积物细菌群落的丰富度不受人为土地利用的增加影响。群落阈值分析表明，农业土地利用比城市土地利用对群落的恢复能力更强。此外，预测宏基因组表明，土地利用变化会导致潜在微生物功能的差异。本研究的结果表明，低水平的城市土地利用变化会改变混合流域沉积物细菌群落组成和预测的功能能力，这可能会影响全球土地利用变化背景下的溪流生态系统服务。
