Nutrients Alter Methane Production and Oxidation in a Thawing Permafrost Mire
Abstract
Permafrost thaw releases nutrients and metals from previously frozen soils and these nutrients may affect important biogeochemical processes including methane (CH4) production and oxidation. Here we assessed how concentrations of nutrients, solutes, and metals varied across four plant communities undergoing permafrost thaw and if these geochemical characteristics affected rates of CH4 production and oxidation. We tested nutrient limitation in CH4 production and oxidation by experimentally adding nitrogen (N), phosphorus (P) and a permafrost leachate to peat across these four plant communities. The upper 20 cm of permafrost contained 715 ± 298 mg m−2 of extractable inorganic N and 20 ± 6 mg m−2 of resin-extractable phosphorus (Presin), for a N:P ratio of 36:1. These low amounts of Presin coincide with high acid-digestible aluminum (Al), iron (Fe), and P concentrations in the permafrost soil and suggest that P may accumulate via sorption and constrain easily available forms of P for plants and microbes. Permafrost leachate additions decreased potential CH4 production rates up to 80% and decreased CH4 oxidation rates by 66%, likely due to inhibitory effects of N in the permafrost. In contrast, organic and inorganic P additions increased CH4 oxidation rates up to 36% in the tall graminoid fen, a community where phosphate availability was low and CH4 production was high. Our results suggest that (1) inorganic N is available immediately from permafrost thaw, while (2) P availability is controlled by sorption properties, and (3) plant community, nutrient stoichiometry, and metal availability modulate how permafrost thaw affects CH4 production and oxidation.
Department
Soil Biogeochemistry and Microbial Ecology; Natural Resources and the Environment; Earth Sciences; Earth Systems Research Center
Publication Date
4-14-2022
Journal Title
Ecosystems
Publisher
Springer
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
Kashi, N.N., Hobbie, E.A., Varner, R.K. et al. Nutrients Alter Methane Production and Oxidation in a Thawing Permafrost Mire. Ecosystems 26, 302–317 (2023). https://doi.org/10.1007/s10021-022-00758-5
Rights
© 2022 The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature