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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Rhizosphere allocation by canopy‐forming species dominates soil CO2 efflux in a subarctic landscape
AU - Parker, Thomas C.
AU - Clemmensen, Karina
AU - Friggens, Nina L
AU - Hartley, Iain P.
AU - Johnson, David
AU - Lindahl, Bjorn
AU - Olofsson, Johan
AU - Siewert, Matthias B
AU - Street, Lorna
AU - Subke, Jens-Arne
AU - Wookey, Philip A.
PY - 2020/9/1
Y1 - 2020/9/1
N2 - In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO 2 efflux remain poorly resolved. In order to identify the role of canopy-forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km 2 of treeline birch (Betula pubescens) forest and willow (Salix lapponum) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO 2 fluxes and belowground productivity. Girdling birches reduced total soil CO 2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO 2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.
AB - In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO 2 efflux remain poorly resolved. In order to identify the role of canopy-forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km 2 of treeline birch (Betula pubescens) forest and willow (Salix lapponum) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO 2 fluxes and belowground productivity. Girdling birches reduced total soil CO 2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO 2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.
KW - Arctic
KW - ectomycorrhizal fungi
KW - girdling
KW - rhizosphere
KW - shrub expansion
KW - soil CO efflux
KW - treeline
U2 - 10.1111/nph.16573
DO - 10.1111/nph.16573
M3 - Journal article
VL - 227
SP - 1818
EP - 1830
JO - New Phytologist
JF - New Phytologist
SN - 1469-8137
IS - 6
ER -