Vulnerability of mineral-associated soil organic carbon to climate across global drylands
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Date
Authors
Díaz-Martínez, Paloma
Maestre, Fernando T.
Moreno-Jiménez, Eduardo
Delgado-Baquerizo, Manuel
Eldridge, David J.
Saiz, Hugo
Gross, Nicolas
Le Bagousse-Pinguet, Yoann
Gozalo, Beatriz
Ochoa, Victoria
Journal Title
Journal ISSN
Volume Title
Publisher
Nature Research
Abstract
Mineral-associated organic carbon (MAOC) constitutes a major fraction of global soil carbon and is assumed less sensitive to climate than particulate organic carbon (POC) due to protection by minerals. Despite its importance for long-term carbon storage, the response of MAOC to changing climates in drylands, which cover more than 40% of the global land area, remains unexplored. Here we assess topsoil organic carbon fractions across global drylands using a standardized field survey in 326 plots from 25 countries and 6 continents. We find that soil biogeochemistry explained the majority of variation in both MAOC and POC. Both carbon fractions decreased with increases in mean annual temperature and reductions in precipitation, with MAOC responding similarly to POC. Therefore, our results suggest that ongoing climate warming and aridification may result in unforeseen carbon losses across global drylands, and that the protective role of minerals may not dampen these effects.
Description
DATA AVAILABILITY :
The data associated with this study are publicly available via figshare (https://doi.org/10.6084/m9.figshare.24678891) (ref. 68).
EXTENDED DATA : EXTENDED DATA FIG. 1. Locations of the 326 plots surveyed across global drylands. Locations are shown as red circles on a global aridity (1 – annual precipitation/potential evapotranspiration) map for drylands (areas with aridity > 0.35), on a less arid-to-more arid color scale. EXTENDED DATA FIG. 2. Effects of climate on particulate organic C (POC) and mineral-associated organic C (MAOC) in dryland soils with organic C contents below and above the median. EXTENDED DATA FIG. 3. Importance of climate, biotic factors, and soil biogeochemistry in random forest models of particulate organic carbon C (POC) and mineral-associated organic carbon C (MAOC) in global drylands. EXTENDED DATA FIG. 4. Effects of soil biogeochemistry on particulate organic C (POC) and mineral-associated organic C (MAOC) contents across global dryland soils. EXTENDED DATA TABLE 1. Summary statistics of the numeric predictors and covariates used to examine the response of particulate organic carbon (POC) and mineral-associated (MAOC) contents to climate across global drylands. EXTENDED DATA TABLE 2. Categorical covariates used to examine the response of particulate organic carbon (POC) and mineral-associated (MAOC) contents to climate in global drylands.
EXTENDED DATA : EXTENDED DATA FIG. 1. Locations of the 326 plots surveyed across global drylands. Locations are shown as red circles on a global aridity (1 – annual precipitation/potential evapotranspiration) map for drylands (areas with aridity > 0.35), on a less arid-to-more arid color scale. EXTENDED DATA FIG. 2. Effects of climate on particulate organic C (POC) and mineral-associated organic C (MAOC) in dryland soils with organic C contents below and above the median. EXTENDED DATA FIG. 3. Importance of climate, biotic factors, and soil biogeochemistry in random forest models of particulate organic carbon C (POC) and mineral-associated organic carbon C (MAOC) in global drylands. EXTENDED DATA FIG. 4. Effects of soil biogeochemistry on particulate organic C (POC) and mineral-associated organic C (MAOC) contents across global dryland soils. EXTENDED DATA TABLE 1. Summary statistics of the numeric predictors and covariates used to examine the response of particulate organic carbon (POC) and mineral-associated (MAOC) contents to climate across global drylands. EXTENDED DATA TABLE 2. Categorical covariates used to examine the response of particulate organic carbon (POC) and mineral-associated (MAOC) contents to climate in global drylands.
Keywords
Mineral-associated organic carbon (MAOC), Particulate organic carbon (POC), Drylands, Climate change, Soil carbon, Soil biogeochemistry, Environmental chemistry, SDG-13: Climate action, SDG-15: Life on land
Sustainable Development Goals
SDG-13:Climate action
SDG-15:Life on land
SDG-15:Life on land
Citation
Díaz-Martínez, P., Maestre, F.T., Moreno-Jiménez, E. et al. Vulnerability of mineral-associated soil organic carbon to climate across global drylands. Nature Climate Change 14, 976–982 (2024). https://doi.org/10.1038/s41558-024-02087-y.