Ecosystems

, Volume 17, Issue 5, pp 792–807

Impacts of Saltwater Incursion on Plant Communities, Anaerobic Microbial Metabolism, and Resulting Relationships in a Restored Freshwater Wetland

  • Kristine N. Hopfensperger
  • Amy J. Burgin
  • Valerie A. Schoepfer
  • Ashley M. Helton
Article

DOI: 10.1007/s10021-014-9760-x

Cite this article as:
Hopfensperger, K.N., Burgin, A.J., Schoepfer, V.A. et al. Ecosystems (2014) 17: 792. doi:10.1007/s10021-014-9760-x

Abstract

Saltwater incursion carries high concentrations of sea salts, including sulfate, which can alter anaerobic microbial processes and plant community composition of coastal freshwater marshes. We studied these phenomena in a recently restored wetland on the coastal plain of North Carolina. We measured water inundation patterns, porewater chemistry, microbial process rates, plant tissue chemistry and iron plaque on plant roots, and quantified plant community composition across a hydrologic and salinity gradient to understand the potential interactions between saltwater incursion and changes in microbial processes and plant communities. Plant communities showed no obvious response to incursion, but were structured by inundation patterns and plant growth form (for example, graminoid versus forb). Saltwater incursion increased chloride and sulfate concentrations in surface and porewater, and drove resulting spatial patterns in anaerobic microbial metabolism rates. Plots experiencing saltwater incursion had higher sulfate reduction rates and were dominated by graminoid plant species (for example, sedges, rushes, and grasses). Graminoid plant species’ roots had greater iron plaque formation than forb and submerged species, indicative that graminoid plant species are supplying more oxygen to the rhizosphere, potentially influencing microbial metabolism. Future studies should focus on how plant and microbial communities may respond to saltwater incursion at different time scales, and on parsing out the influence that plants and microbes have on each other as freshwater wetlands experience sea level rise.

Keywords

microbial processesfreshwater marshmethanogenesissulfur reductioniron reductionporewater chemistryecosystem processes

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Kristine N. Hopfensperger
    • 1
  • Amy J. Burgin
    • 2
  • Valerie A. Schoepfer
    • 2
  • Ashley M. Helton
    • 3
    • 4
  1. 1.Department of Biological SciencesNorthern Kentucky UniversityHighland HeightsUSA
  2. 2.School of Natural ResourcesUniversity of Nebraska-LincolnLincolnUSA
  3. 3.Department of BiologyDuke UniversityDurhamUSA
  4. 4.Department of Natural Resources and the Environment & The Center for Environmental Sciences and EngineeringUniversity of ConnecticutStorrsUSA