Peatlands are an integral part of the natural carbon cycle, but have often been drained and used for agricultural purposes. Rewetting of drained peatlands can help mitigate anthropogenic climate change, and their health and function as a carbon sink is integral to achieving a sustainable future. Rewetting reduces the output of carbon dioxide (CO₂) and nitrous oxide (N₂O) but comes with increased methane (CH₄) emissions. For coastal peatlands, the magnitude of CH₄ release may be reduced through rewetting with brackish water which is thought to simultaneously promote methanotrophy and inhibit methanogenesis. To investigate this assumption and elucidate the influence of biogeochemistry on CH₄ cycling, a 1-year intensive monitoring campaign of a recently rewetted coastal peatland was initiated in July 2022, with biweekly surface water and porewater sampling. The first results of this monitoring will be presented, including pH measurements, CH₄ and CO₂ concentrations, δ¹³C-CH₄, δ¹³C-CO₂, iron speciation, acetate, methylamines, major cations, anions, nutrients, and dissolved organic carbon as well as organic carbon fractions to characterize the biogeochemistry and the intricacies of methane production, consumption, and release at the site.

Primary Presenter: Sara Anthony, University of Rostock (sara.anthony@uni-rostock.de)

Authors:

Sara Anthony, Landscape Ecology, Faculty of Agricultural and Environmental Sciences, University of Rostock  (sara.anthony@uni-rostock.de)

Dominik Zak, Catchment Science and Environmental Management, Department of Ecoscience, Aarhus University; Department of Ecohydrology and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries  (doz@ecos.au.dk)

Klaus-Holger Knorr, Ecohydrology and Biogeochemistry Research Group, Institute of Landscape Ecology, University of Münster  (kh.knorr@uni-muenster.de)

Susanne Liebner, GFZ German Research Center for Geosciences, Helmholtz Centre Potsdam, Section Geomicrobiology; Institute of Biochemistry and Biology, University of Potsdam  (sliebner@gfz-potsdam.de)

Gerald Jurasinski, Peatland Science, Institute of Botany and Landscape Ecology, University of Greifswald; Landscape Ecology, Faculty of Agricultural and Environmental Sciences, University of Rostock  (gerald.jurasinski@uni-greifswald.de)