TY - JOUR
T1 - Beyond bulk
T2 - Density fractions explain heterogeneity in global soil carbon abundance and persistence
AU - Heckman, Katherine
AU - Hicks Pries, Caitlin E.
AU - Lawrence, Corey R.
AU - Rasmussen, Craig
AU - Crow, Susan E.
AU - Hoyt, Alison M.
AU - von Fromm, Sophie F.
AU - Shi, Zheng
AU - Stoner, Shane
AU - McGrath, Casey
AU - Beem-Miller, Jeffrey
AU - Berhe, Asmeret Asefaw
AU - Blankinship, Joseph C.
AU - Keiluweit, Marco
AU - Marín-Spiotta, Erika
AU - Monroe, J. Grey
AU - Plante, Alain F.
AU - Schimel, Joshua
AU - Sierra, Carlos A.
AU - Thompson, Aaron
AU - Wagai, Rota
N1 - Funding Information:
Essential support for this project came from the U.S. Geological Survey (USGS) John Wesley Powell Center for Analysis and Synthesis Working Group on Soil Carbon: “What lies below? Improving quantification and prediction of soil carbon storage, stability, and susceptibility to disturbance.” Additional funding was provided by the Max Planck Institute for Biogeochemistry, the European Research Council (Horizon 2020 Research and Innovation Programme, grant agreement 695101), the USGS Land Change Science mission area, and the US Department of Agriculture (Soil Carbon Working Group award 2018-67003-27935). We specifically acknowledge the intellectual and financial contributions of Dr. Susan Trumbore of the Max Planck Institute for Biogeochemistry. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Funding Information:
Essential support for this project came from the U.S. Geological Survey (USGS) John Wesley Powell Center for Analysis and Synthesis Working Group on Soil Carbon: “What lies below? Improving quantification and prediction of soil carbon storage, stability, and susceptibility to disturbance.” Additional funding was provided by the Max Planck Institute for Biogeochemistry, the European Research Council (Horizon 2020 Research and Innovation Programme, grant agreement 695101), the USGS Land Change Science mission area, and the US Department of Agriculture (Soil Carbon Working Group award 2018‐67003‐27935). We specifically acknowledge the intellectual and financial contributions of Dr. Susan Trumbore of the Max Planck Institute for Biogeochemistry. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Publisher Copyright:
© 2021 John Wiley & Sons Ltd. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
PY - 2022/2
Y1 - 2022/2
N2 - 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 (<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.
AB - 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 (<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.
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U2 - 10.1111/gcb.16023
DO - 10.1111/gcb.16023
M3 - Article
C2 - 34862692
AN - SCOPUS:85121353213
VL - 28
SP - 1178
EP - 1196
JO - Global Change Biology
JF - Global Change Biology
SN - 1354-1013
IS - 3
ER -