Plant-mediated CH4 exchange in wetlands: A review of mechanisms and measurement methods with implications for modelling

Mengyu Ge; Aino Korrensalo; Raija Laiho; Lukas Kohl; Annalea Lohila; Mari Pihlatie; Xuefei Li; Anna M Laine; Jani Anttila; Anuliina Putkinen; Weifeng Wang; Markku Koskinen

doi:10.1016/j.scitotenv.2023.169662

Plant-mediated CH₄ exchange in wetlands: A review of mechanisms and measurement methods with implications for modelling

Sci Total Environ. 2024 Mar 1:914:169662. doi: 10.1016/j.scitotenv.2023.169662. Epub 2023 Dec 28.

Authors

Mengyu Ge¹, Aino Korrensalo², Raija Laiho³, Lukas Kohl⁴, Annalea Lohila⁵, Mari Pihlatie⁶, Xuefei Li⁷, Anna M Laine⁸, Jani Anttila³, Anuliina Putkinen⁹, Weifeng Wang¹⁰, Markku Koskinen⁹

Affiliations

¹ Department of Agricultural Sciences, University of Helsinki, PO Box 56, Helsinki 00014, Finland; Institute for Atmospheric and Earth System Research (INAR)/Forest Sciences, University of Helsinki, PO Box 56, Helsinki 00014, Finland. Electronic address: [email protected].
² Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, Kuopio 80101, Finland; Natural Resources Institute Finland, Latokartanonkaari 9, Helsinki 00790, Finland.
³ Natural Resources Institute Finland, Latokartanonkaari 9, Helsinki 00790, Finland.
⁴ Department of Agricultural Sciences, University of Helsinki, PO Box 56, Helsinki 00014, Finland; Institute for Atmospheric and Earth System Research (INAR)/Forest Sciences, University of Helsinki, PO Box 56, Helsinki 00014, Finland; Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, Kuopio 80101, Finland.
⁵ Finnish Meteorological Institute, Erik Palménin aukio 1, Helsinki 00560, Finland.
⁶ Department of Agricultural Sciences, University of Helsinki, PO Box 56, Helsinki 00014, Finland; Institute for Atmospheric and Earth System Research (INAR)/Forest Sciences, University of Helsinki, PO Box 56, Helsinki 00014, Finland; Department of Agricultural Sciences, Viikki Plant Science Centre (ViPS), University of Helsinki, PO Box 56, 00014 Helsinki, Finland.
⁷ Institute for Atmospheric and Earth System Research (INAR)/Forest Sciences, University of Helsinki, PO Box 56, Helsinki 00014, Finland.
⁸ Geological Survey of Finland, PO Box 1237, 70211 Kuopio, Finland.
⁹ Department of Agricultural Sciences, University of Helsinki, PO Box 56, Helsinki 00014, Finland; Institute for Atmospheric and Earth System Research (INAR)/Forest Sciences, University of Helsinki, PO Box 56, Helsinki 00014, Finland.
¹⁰ College of Biology and the Environment, Nanjing Forestry University, 210037 Nanjing, China.

PMID: 38159777
DOI: 10.1016/j.scitotenv.2023.169662

Abstract

Plant-mediated CH₄ transport (PMT) is the dominant pathway through which soil-produced CH₄ can escape into the atmosphere and thus plays an important role in controlling ecosystem CH₄ emission. PMT is affected by abiotic and biotic factors simultaneously, and the effects of biotic factors, such as the dominant plant species and their traits, can override the effects of abiotic factors. Increasing evidence shows that plant-mediated CH₄ fluxes include not only PMT, but also within-plant CH₄ production and oxidation due to the detection of methanogens and methanotrophs attached to the shoots. Despite the inter-species and seasonal differences, and the probable contribution of within-plant microbes to total plant-mediated CH₄ exchange (PME), current process-based ecosystem models only estimate PMT based on the bulk biomass or leaf area index of aerenchymatous plants. We highlight five knowledge gaps to which more research efforts should be devoted. First, large between-species variation, even within the same family, complicates general estimation of PMT, and calls for further work on the key dominant species in different types of wetlands. Second, the interface (rhizosphere-root, root-shoot, or leaf-atmosphere) and plant traits controlling PMT remain poorly documented, but would be required for generalizations from species to relevant functional groups. Third, the main environmental controls of PMT across species remain uncertain. Fourth, the role of within-plant CH₄ production and oxidation is poorly quantified. Fifth, the simplistic description of PMT in current process models results in uncertainty and potentially high errors in predictions of the ecosystem CH₄ flux. Our review suggest that flux measurements should be conducted over multiple growing seasons and be paired with trait assessment and microbial analysis, and that trait-based models should be developed. Only then we are capable to accurately estimate plant-mediated CH₄ emissions, and eventually ecosystem total CH₄ emissions at both regional and global scales.

Keywords: Drivers; Mechanisms; Modelling; Plant CH(4) transport; Processes; Wetland plants.

Publication types

Review

MeSH terms

Biomass
Carbon Dioxide / analysis
Ecosystem*
Methane / analysis
Plants / metabolism
Soil
Wetlands*

Substances

Methane
Carbon Dioxide
Soil