A tipping point in carbon storage when forest expands into tundra is related to mycorrhizal recycling of nitrogen.
Ecol Lett
; 24(6): 1193-1204, 2021 Jun.
Article
em En
| MEDLINE
| ID: mdl-33754469
ABSTRACT
Tundra ecosystems are global belowground sinks for atmospheric CO2 . Ongoing warming-induced encroachment by shrubs and trees risks turning this sink into a CO2 source, resulting in a positive feedback on climate warming. To advance mechanistic understanding of how shifts in mycorrhizal types affect long-term carbon (C) and nitrogen (N) stocks, we studied small-scale soil depth profiles of fungal communities and C-N dynamics across a subarctic-alpine forest-heath vegetation gradient. Belowground organic stocks decreased abruptly at the transition from heath to forest, linked to the presence of certain tree-associated ectomycorrhizal fungi that contribute to decomposition when mining N from organic matter. In contrast, ericoid mycorrhizal plants and fungi were associated with organic matter accumulation and slow decomposition. If climatic controls on arctic-alpine forest lines are relaxed, increased decomposition will likely outbalance increased plant productivity, decreasing the overall C sink capacity of displaced tundra.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carbono
/
Micorrizas
Idioma:
En
Revista:
Ecol Lett
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Suécia