Lowering water table reduces carbon sink strength and carbon stocks in northern peatlands

© 2022 The Authors. Global Change Biology published by John Wiley & Sons Ltd.

Bibliographische Detailangaben
Veröffentlicht in:Global change biology. - 1999. - 28(2022), 22 vom: 29. Nov., Seite 6752-6770
1. Verfasser: Kwon, Min Jung (VerfasserIn)
Weitere Verfasser: Ballantyne, Ashley, Ciais, Philippe, Qiu, Chunjing, Salmon, Elodie, Raoult, Nina, Guenet, Bertrand, Göckede, Mathias, Euskirchen, Eugénie S, Nykänen, Hannu, Schuur, Edward A G, Turetsky, Merritt R, Dieleman, Catherine M, Kane, Evan S, Zona, Donatella
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2022
Zugriff auf das übergeordnete Werk:Global change biology
Schlagworte:Journal Article carbon flux carbon stock drainage high latitude land surface model manipulation experiment permafrost thaw Greenhouse Gases Soil mehr... Carbon Dioxide 142M471B3J Carbon 7440-44-0 Methane OP0UW79H66
Beschreibung
Zusammenfassung:© 2022 The Authors. Global Change Biology published by John Wiley & Sons Ltd.
Peatlands at high latitudes have accumulated >400 Pg carbon (C) because saturated soil and cold temperatures suppress C decomposition. This substantial amount of C in Arctic and Boreal peatlands is potentially subject to increased decomposition if the water table (WT) decreases due to climate change, including permafrost thaw-related drying. Here, we optimize a version of the Organizing Carbon and Hydrology In Dynamic Ecosystems model (ORCHIDEE-PCH4) using site-specific observations to investigate changes in CO2 and CH4 fluxes as well as C stock responses to an experimentally manipulated decrease of WT at six northern peatlands. The unmanipulated control peatlands, with the WT <20 cm on average (seasonal max up to 45 cm) below the surface, currently act as C sinks in most years (58 ± 34 g C m-2  year-1 ; including 6 ± 7 g C-CH4 m-2  year-1 emission). We found, however, that lowering the WT by 10 cm reduced the CO2 sink by 13 ± 15 g C m-2  year-1 and decreased CH4 emission by 4 ± 4 g CH4 m-2  year-1 , thus accumulating less C over 100 years (0.2 ± 0.2 kg C m-2 ). Yet, the reduced emission of CH4 , which has a larger greenhouse warming potential, resulted in a net decrease in greenhouse gas balance by 310 ± 360 g CO2-eq  m-2  year-1 . Peatlands with the initial WT close to the soil surface were more vulnerable to C loss: Non-permafrost peatlands lost >2 kg C m-2 over 100 years when WT is lowered by 50 cm, while permafrost peatlands temporally switched from C sinks to sources. These results highlight that reductions in C storage capacity in response to drying of northern peatlands are offset in part by reduced CH4 emissions, thus slightly reducing the positive carbon climate feedbacks of peatlands under a warmer and drier future climate scenario
Beschreibung:Date Completed 18.10.2022
Date Revised 07.01.2023
published: Print-Electronic
Citation Status MEDLINE
ISSN:1365-2486
DOI:10.1111/gcb.16394