Global turnover of soil mineral-associated and particulate organic carbon.

Zhou, Zhenghu; Ren, Chengjie; Wang, Chuankuan; Delgado-Baquerizo, Manuel; Luo, Yiqi; Luo, Zhongkui; Du, Zhenggang; Zhu, Biao et al. · Nat Commun · 2024

basic_science · Level V

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Abstract

Soil organic carbon (SOC) persistence is predominantly governed by mineral protection, consequently, soil mineral-associated (MAOC) and particulate organic carbon (POC) turnovers have different impacts on the vulnerability of SOC to climate change. Here, we generate the global MAOC and POC maps using 8341 observations and then infer the turnover times of MAOC and POC by a data-model integration approach. Global MAOC and POC storages are <math xmlns="http://www.w3.org/1998/Math/MathML"> <msubsup><mrow><mn>975</mn></mrow> <mrow><mn>964</mn></mrow> <mrow><mn>987</mn></mrow> </msubsup> </math> Pg C (mean with 5% and 95% quantiles) and <math xmlns="http://www.w3.org/1998/Math/MathML"> <msubsup><mrow><mn>330</mn></mrow> <mrow><mn>323</mn></mrow> <mrow><mn>337</mn></mrow> </msubsup> </math> Pg C, while global mean MAOC and POC turnover times are <math xmlns="http://www.w3.org/1998/Math/MathML"> <msubsup><mrow><mn>129</mn></mrow> <mrow><mn>45</mn></mrow> <mrow><mn>383</mn></mrow> </msubsup> </math> yr and <math xmlns="http://www.w3.org/1998/Math/MathML"> <msubsup><mrow><mn>23</mn></mrow> <mrow><mn>5</mn></mrow> <mrow><mn>82</mn></mrow> </msubsup> </math> yr in the top meter, respectively. Climate warming-induced acceleration of MAOC and POC decomposition is greater in subsoil than that in topsoil. Overall, the global atlas of MAOC and POC turnover, together with the global distributions of MAOC and POC stocks, provide a benchmark for Earth system models to diagnose SOC-climate change feedback.