Rhizosphere allocation by canopy-forming species dominates soil CO2 efflux in a subarctic landscape.
New Phytol
; 227(6): 1818-1830, 2020 09.
Article
en En
| MEDLINE
| ID: mdl-32248524
ABSTRACT
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 CO2 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 km2 of treeline birch (Betula pubescens) forest and willow (Salix lapponum) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 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 CO2 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.
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Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Suelo
/
Ecosistema
Tipo de estudio:
Prognostic_studies
País como asunto:
Europa
Idioma:
En
Año:
2020
Tipo del documento:
Article