Land use-induced soil carbon loss in the dry tropics nearly offsets gains in northern lands

作者：Huan Wang, Philippe Ciais, Hui Yang, Pete Smith, Giacomo Grassi, Clemens Schwingshackl, Panos Panagos, Yinon M. Bar‐On, Stephen Sitch, Frédéric Chevallier, Paul I. Palmer, Xiaojun Li, Songbai Hong, Jinfeng Chang, Clément Albergel, Lei Fan, Kai Wang, Laibao Liu, Frédéric Frappart, Jean‐Pierre Wigneron · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-64929-3 · 被引用次数：5 · 研究领域：Soil Carbon and Nitrogen Dynamics、Peatlands and Wetlands Ecology、Fire effects on ecosystems

Soil carbon changes are difficult to measure globally, and global models are poorly constrained. Here, we propose a framework to map annual changes in soil carbon and litter (SOCL) as the difference between the net land CO2 flux from atmospheric inversions and satellite-based maps of biomass changes. We show that SOCL accumulated globally at a rate of about 0.34 ± 0.30 ( ± 1 sigma) billion tonnes of carbon per year (PgC yr−1) during 2011-2020. The largest SOCL sink is found in boreal regions (0.93 ± 0.45 PgC yr−1 in total) particularly in undisturbed peatlands and managed forests. The largest losses occur in the dry tropics (−0.50 ± 0.47 PgC yr−1) and correspond with agricultural expansion from land use change, cropland management and grazing. By contrast, forests in the wet tropics act as a net soil carbon sink (0.32 ± 0.35 PgC yr−1). Our findings highlight the large mitigation opportunities in the dry tropics to restore agricultural soil carbon. Soil carbon loss from human agriculture-related land use in the dry tropics largely offsets gains in northern lands, leading to a small net sink of 0.34 ± 0.30 PgC yr−1 at a global scale.