Beyond bulk: Density fractions explain heterogeneity in global soil carbon abundance and persistence

Autor: Susan E. Crow, Erika Marin-Spiotta, Carlos A. Sierra, Casey McGrath, Katherine Heckman, J. Grey Monroe, Sophie F. von Fromm, Alain F. Plante, Zheng Shi, Jeffrey Beem-Miller, Aaron Thompson, Marco Keiluweit, Shane Stoner, Caitlin E. Hicks Pries, Alison M. Hoyt, Corey R. Lawrence, Craig Rasmussen, Joseph C. Blankinship, Joshua P. Schimel, Asmeret Asefaw Berhe, Rota Wagai
Rok vydání: 2021
Předmět:
Zdroj: Global Change Biology. 28:1178-1196
ISSN: 1365-2486
1354-1013
DOI: 10.1111/gcb.16023
Popis: 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-1 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-1 soil) to climate varied among pools and with depth. Mineral-associated C in surface soils (
Databáze: OpenAIRE
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