Stream ecosystems are vital for industries, agriculture and health. Changes in land use disrupt the function of riparian landscapes and alter the environmental quality and biodiversity of adjacent streams. Recently, microbial community diversity has been shown to be a promising indicator of environmental changes resulting from increasing anthropogenic activity. The intensity and degree of land alteration can directly impact the biodiversity and function of stream microbial communities due to changes in underlying hydrology and increased pollutant load. Understanding the impact of anthropogenic land use change on stream microbial communities is important because microorganisms cycle nutrients and transform pollutants in stream sediments, which are hallmarks of ecosystem health. Here we examined the influence of disparate land uses on the spatial and temporal variation in microbial community structure at a fine temporal resolution. This study was conducted using an experimental watershed approach in the West Run watershed (Morgantown, WV) across six sites with diverse land use type (i.e., urban, agricultural, and forest). Samples were collected every two weeks from May to September 2017, from which microbial community composition was assessed by 16S rRNA gene sequencing.
Results/Conclusions
Community richness differed significantly across sites (P<0.01), but did not vary over time. Microbial community composition was significantly different between sites (P<0.01) and over time in a subset of sites. For example, the forested reference site differed significantly from the agricultural site from the early season through mid-summer (P<0.05). The urban site differed from the reference site (P<0.05) and forested site (P=0.05) in the early season only. These findings indicate microbial community composition is most influenced by land use (site), and further, that changes in land use may amplify community responses to seasonal changes.