Agricultural land use impacts microbial community structure of streambed sediments

Abstract

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 83:225-236 (2019) - DOI: https://doi.org/10.3354/ame01905 Agricultural land use impacts microbial community structure of streambed sediments Caitlyn A. Griffith1, Peng Shang2, YueHan Lu2, Ethan J. Theuerkauf3, Antonio B. Rodriguez4, Robert H. Findlay1,* 1Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama 35401, USA 2Department of Geological Sciences, The University of Alabama, 201 7th Ave, Tuscaloosa, Alabama 35485, USA 3Illinois State Geological Survey, Prairie Research Institute, The University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA 4University of North Carolina, Institute of Marine Sciences, 3431 Arendell St, Morehead City, North Carolina 28557, USA *Corresponding author: rfindlay@ua.edu ABSTRACT: Agricultural land use is known to adversely affect freshwater ecosystems, and recent studies have shown that it can significantly alter dissolved organic matter (DOM) concentrations and quality. DOM quantity and quality are key determinants of microbial community structure in streams and have been linked to changes in community abundance and composition. Considering the vital ecological role sediment microbes play in stream ecosystems, it is important to understand how agricultural land use changes affect stream microbial community structure. This study was conducted to determine if variation in sediment microbial biomass community structure could be attributed to differences in agricultural land use. Microbial biomass, microbial community structure, and stream water parameters were compared on 2 dates from 6 sites representing a gradient of agricultural land use from 18 to 64% within the Bear Creek Watershed in northwest Alabama, USA. Total microbial biomass, determined as phospholipid phosphate, was strongly influenced by sediment surface area and, to a lesser extent, correlated with sampling date and land use. Sediment microbial community structure, determined by phospholipid fatty acid analysis, was significantly correlated to percent agricultural land use in the watershed, as well as stream water DOM humification index, and sediment δ15N values and surface area. Microbial community structure also differed between sampling dates. These findings demonstrate that agricultural land use is linked via alteration of stream water and sediment organic matter to changes in sediment microbial structure which may, at least in part, account for widely observed changes in stream ecosystem functioning associated with agricultural activities. KEY WORDS: Microbial community structure · Streams · Agricultural land use · DOM Full text in pdf format Supplementary material PreviousNextCite this article as: Griffith CA, Shang P, Lu Y, Theuerkauf EJ, Rodriguez AB, Findlay RH (2019) Agricultural land use impacts microbial community structure of streambed sediments. Aquat Microb Ecol 83:225-236. https://doi.org/10.3354/ame01905 Export citation Mail this link - Contents Mailing Lists - RSS Facebook - Tweet - linkedIn Cited by Published in AME Vol. 83, No. 3. Online publication date: October 02, 2019 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2019 Inter-Research.