Beyond bulk: Density fractions explain heterogeneity in global soil carbon abundance and persistence.
Détails
ID Serval
serval:BIB_CF7AFE2867D7
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Beyond bulk: Density fractions explain heterogeneity in global soil carbon abundance and persistence.
Périodique
Global change biology
ISSN
1365-2486 (Electronic)
ISSN-L
1354-1013
Statut éditorial
Publié
Date de publication
02/2022
Peer-reviewed
Oui
Volume
28
Numéro
3
Pages
1178-1196
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: ppublish
Publication Status: ppublish
Résumé
Understanding the controls on the amount and persistence of soil organic carbon (C) is essential for predicting its sensitivity to global change. The response may depend on whether C is unprotected, isolated within aggregates, or protected from decomposition by mineral associations. Here, we present a global synthesis of the relative influence of environmental factors on soil organic C partitioning among pools, abundance in each pool (mg C g <sup>-1</sup> soil), and persistence (as approximated by radiocarbon abundance) in relatively unprotected particulate and protected mineral-bound pools. We show that C within particulate and mineral-associated pools consistently differed from one another in degree of persistence and relationship to environmental factors. Soil depth was the best predictor of C abundance and persistence, though it accounted for more variance in persistence. Persistence of all C pools decreased with increasing mean annual temperature (MAT) throughout the soil profile, whereas persistence increased with increasing wetness index (MAP/PET) in subsurface soils (30-176 cm). The relationship of C abundance (mg C g <sup>-1</sup> soil) to climate varied among pools and with depth. Mineral-associated C in surface soils (<30 cm) increased more strongly with increasing wetness index than the free particulate C, but both pools showed attenuated responses to the wetness index at depth. Overall, these relationships suggest a strong influence of climate on soil C properties, and a potential loss of soil C from protected pools in areas with decreasing wetness. Relative persistence and abundance of C pools varied significantly among land cover types and soil parent material lithologies. This variability in each pool's relationship to environmental factors suggests that not all soil organic C is equally vulnerable to global change. Therefore, projections of future soil organic C based on patterns and responses of bulk soil organic C may be misleading.
Mots-clé
Carbon, Climate, Minerals, Soil, Temperature, climate change, persistence, radiocarbon, soil carbon, soil fractions, soil organic matter, terrestrial carbon cycle
Pubmed
Web of science
Création de la notice
22/07/2024 10:08
Dernière modification de la notice
23/07/2024 5:56