Microbial Ecology

, Volume 73, Issue 3, pp 630–644

Microbial Community Functional Potential and Composition Are Shaped by Hydrologic Connectivity in Riverine Floodplain Soils

  • William A. Argiroff
  • Donald R. Zak
  • Christine M. Lanser
  • Michael J. Wiley
Soil Microbiology

Abstract

Riverine floodplains are ecologically and economically valuable ecosystems that are heavily threatened by anthropogenic stressors. Microbial communities in floodplain soils mediate critical biogeochemical processes, yet we understand little about the relationship between these communities and variation in hydrologic connectivity related to land management or topography. Here, we present metagenomic evidence that differences among microbial communities in three floodplain soils correspond to a long-term gradient of hydrologic connectivity. Specifically, all strictly anaerobic taxa and metabolic pathways were positively associated with increased hydrologic connectivity and flooding frequency. In contrast, most aerobic taxa and all strictly aerobic pathways were negatively related to hydrologic connectivity and flooding frequency. Furthermore, the genetic potential to metabolize organic compounds tended to decrease as hydrologic connectivity increased, which may reflect either the observed concomitant decline of soil organic matter or the parallel increase in both anaerobic taxa and pathways. A decline in soil N, accompanied by an increased genetic potential for oligotrophic N acquisition subsystems, suggests that soil nutrients also shape microbial communities in these soils. We conclude that differences among floodplain soil microbial communities can be conceptualized along a gradient of hydrologic connectivity. Additionally, we show that these differences are likely due to connectivity-related variation in flooding frequency, soil organic matter, and soil N. Our findings are particularly relevant to the restoration and management of microbially mediated biogeochemical processes in riverine floodplain wetlands.

Keywords

Microbial community Hydrologic connectivity Riverine floodplain Soil Wetland restoration 

Supplementary material

248_2016_883_MOESM1_ESM.pdf (704 kb)
ESM 1(PDF 704 kb)

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • William A. Argiroff
    • 1
  • Donald R. Zak
    • 1
    • 2
  • Christine M. Lanser
    • 1
  • Michael J. Wiley
    • 1
  1. 1.School of Natural Resources and EnvironmentUniversity of MichiganAnn ArborUSA
  2. 2.Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborUSA

Personalised recommendations