Opposing seasonal temperature dependencies of CO2 and CH4 emissions from wetlands. Issue 4 (23rd November 2022)

• Record Type: Journal Article
• Authors: Li, Jinquan; Pei, Junmin; Fang, Changming; Li, Bo; Nie, Ming
• Is Part Of: Global change biology. Volume 29:Issue 4(2023)
• Page Start: 1133
• Page End: 1143
• Publication Date: 2022-11-23
• Subjects: carbon sink -- greenhouse gases -- methane -- temperature sensitivity -- wetland; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.16528
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: Wetlands are critically important to global climate change because of their role in modulating the release of atmospheric greenhouse gases (GHGs) carbon dioxide (CO2 ) and methane (CH4 ). Temperature plays a crucial role in wetland GHG emissions, while the general pattern for seasonal temperature dependencies of wetland CO2 and CH4 emissions is poorly understood. Here we show opposite seasonal temperature dependencies of CO2 and CH4 emissions by using 36, 663 daily observations of simultaneous measurements of ecosystem‐scale CO2 and CH4 emissions in 42 widely distributed wetlands from the FLUXNET‐CH4 database. Specifically, the temperature dependence of CO2 emissions decreased with increasing monthly mean temperature, but the opposite was true for that of CH4 emissions. Neglecting seasonal temperature dependencies may overestimate wetland CO2 and CH4 emissions compared to the use of a year‐based static and consistent temperature dependence parameter when only considering temperature effects. Our findings highlight the importance of incorporating the remarkable seasonality in temperature dependence into process‐based biogeochemical models to predict feedbacks of wetland GHG emissions to climate warming. Abstract : Seasonal patterns of temperature dependencies of CO2 and CH4 emissions estimated by using 36, 663 daily observations of simultaneous measurements of ecosystem‐scale CO2 and CH4 emissions in 42 widely distributed wetlands from the FLUXNET‐CH4 database. Monthly mean temperature dependence values of CO2 and CH4 emissions (a) and of the CH4 :CO2 emission ratio (b). Monthly mean temperature dependence values indicated by activation energies were estimated using mixed‐effects models after fitting Boltzmann–Arrhenius functions to the emission data with site‐level random effects on the activation energy and emission rate at a fixed temperature.