Effects of hydrology and past land-use on carbon and microbial communities in restored wetlands

Session: Wetland Restoration in the Great Lakes Basin: Research and Innovation (2)

Benjamin Hamilton, Rochester Institute of Technology, [email protected]
Carmody McCalley, Rochester Institute of Technology, [email protected]
Christy Tyler, Rochester Institute of Technology, [email protected]
Nathan Eddingsaas, Rochester Institute of Technology, [email protected]
Andre Hudson, Rochester Institute of Technology, [email protected]

Abstract

Multiple wetland ecosystem services such as carbon sequestration and nutrient removal are influenced by microbial communities and dissolved organic matter (DOM). We examined DOM composition, carbon metabolism, and microbial communities in three created wetlands to characterize patterns in these factors across created systems. The wetlands have distinct hydrology, vegetation and antecedent land-use, including a gravel mine repository, agricultural field, and cow pasture. Porewater and soil were collected from each wetland in spring, summer, and fall. DOM was analyzed using NMR spectroscopy, soil microbial community composition was determined using 16S ribosomal sequencing, and CO₂ and CH₄ production rates were measured in anaerobic soil incubations. The wetland built on former agricultural fields had DOM with significantly higher proportions of carbohydrates in the spring and higher proportions of CRAM in the summer and fall than the other sites, as well as seasonal patterns of CRAM and Alkyl proportions. Average CH₄/CO₂ production ratios were approximately 1:1 for all sites in the spring and summer and approached 3:1 in the fall, with no differences in gas production between sites. This suggests that while DOM characteristics and microbial communities in restored wetlands are impacted by site characteristics, these differences have less effect on carbon metabolism.