Final published version
Licence: CC BY: Creative Commons Attribution 4.0 International License
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Plant functional type indirectly affects peatland carbon fluxes and their sensitivity to environmental change
AU - Whitaker, Jeanette
AU - Richardson, Harriett R.
AU - Ostle, Nicholas J.
AU - Armstrong, Alona
AU - Waldron, Susan
N1 - This is the peer reviewed version of the following article: Whitaker, J, Richardson, HR, Ostle, NJ, Armstrong, A, Waldron, S. Plant functional type indirectly affects peatland carbon fluxes and their sensitivity to environmental change. Eur J Soil Sci. 2021; 72: 1042– 1053. https://doi.org/10.1111/ejss.13048 which has been published in final form at https://onlinelibrary.wiley.com/doi/10.1111/ejss.13048 This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
PY - 2021/3/20
Y1 - 2021/3/20
N2 - The sensitivity of peatland carbon (C) fluxes to changes in climate and hydrology are uncertain due to the complex interactions between plants and peat properties. In this study we examine how peat cores taken from under three plant functional types (PFT) (bryophyte, graminoid and ericoid) differ in their biotic and abiotic properties and how this indirectly modulates the response of C fluxes to environmental change. Peat cores taken from under three PFTs had their aboveground vegetation removed to exclude direct plant-mediated effects, and were incubated in a temperature x water table factorial experiment at 12, 14 and 16 degrees C (air temperature) with the water table level -25, -15 or -5 cm below the peat surface. Carbon dioxide (CO2) and methane (CH4) fluxes were measured over 11 months. Emissions of CO(2)and CH(4)increased with temperature, with strong positive (CH4) and negative (CO2) interactions with increasing water table level. There were significant effects of removed PFT on the environmental sensitivity of CH4, but not CO(2)fluxes. CH(4)emissions were greatest in peat with graminoid PFT removed at the warmest temperature but these indirect effects were not explained by peat abiotic or biotic properties, which did not differ between PFTs. These results show that climate change-induced expansion of graminoids in northern peatlands will have direct and indirect effects on C fluxes and the stability of peatland C stores. These responses will be determined by the interactive effects of vegetation composition, hydrology and warming on methane-cycling microbial communities. HighlightsPeatland carbon flux strength under a changing climate is influenced by PFT. Peat from under graminoid PFT emits more methane than peat from under bryophyte or ericoid PFT. Prior PFT cover influenced methane emissions, but did not affect peat abiotic or biotic properties. Increases in graminoid cover with climate change could indirectly increase peatland methane fluxes.
AB - The sensitivity of peatland carbon (C) fluxes to changes in climate and hydrology are uncertain due to the complex interactions between plants and peat properties. In this study we examine how peat cores taken from under three plant functional types (PFT) (bryophyte, graminoid and ericoid) differ in their biotic and abiotic properties and how this indirectly modulates the response of C fluxes to environmental change. Peat cores taken from under three PFTs had their aboveground vegetation removed to exclude direct plant-mediated effects, and were incubated in a temperature x water table factorial experiment at 12, 14 and 16 degrees C (air temperature) with the water table level -25, -15 or -5 cm below the peat surface. Carbon dioxide (CO2) and methane (CH4) fluxes were measured over 11 months. Emissions of CO(2)and CH(4)increased with temperature, with strong positive (CH4) and negative (CO2) interactions with increasing water table level. There were significant effects of removed PFT on the environmental sensitivity of CH4, but not CO(2)fluxes. CH(4)emissions were greatest in peat with graminoid PFT removed at the warmest temperature but these indirect effects were not explained by peat abiotic or biotic properties, which did not differ between PFTs. These results show that climate change-induced expansion of graminoids in northern peatlands will have direct and indirect effects on C fluxes and the stability of peatland C stores. These responses will be determined by the interactive effects of vegetation composition, hydrology and warming on methane-cycling microbial communities. HighlightsPeatland carbon flux strength under a changing climate is influenced by PFT. Peat from under graminoid PFT emits more methane than peat from under bryophyte or ericoid PFT. Prior PFT cover influenced methane emissions, but did not affect peat abiotic or biotic properties. Increases in graminoid cover with climate change could indirectly increase peatland methane fluxes.
KW - carbon cycling
KW - climate change
KW - greenhouse gas emissions
KW - methane
KW - peat
KW - plant functional type
KW - METHANE DYNAMICS
KW - TEMPERATURE SENSITIVITY
KW - WATER-LEVEL
KW - SOIL
KW - NORTHERN
KW - CO2
KW - DIOXIDE
KW - EMISSIONS
KW - RESPONSES
KW - MOISTURE
U2 - 10.1111/ejss.13048
DO - 10.1111/ejss.13048
M3 - Journal article
VL - 72
SP - 1042
EP - 1053
JO - European Journal of Soil Science
JF - European Journal of Soil Science
SN - 1351-0754
IS - 2
ER -