第九届青年地学论坛

Separating soil organic carbon (SOC) into particulate (POC) and mineral-associated organic carbon (MAOC) has advanced our understanding of the form and persistence of SOC. However, the global distribution, drivers, and future changes of POC and MAOC stock remain elusive. Here, we compiled a comprehensive database of POC and MAOC stock with 3,410 observations across six continents. Our analysis showed that the mean stock of POC was 4.75 ± 3.70 kg m^-2 and MAOC was 5.82 ± 2.96 kg m^-2 in 0-30 cm soil. Land cover and mean annual temperature were the key drivers for global POC and MAOC stock. The high-latitude tundra was identified as the loss hotspot of global SOC stock, primarily due to the loss of POC stock. The predicted increase in forest POC and MAOC stock was greater than that of other land cover, becoming the hotspot of SOC accumulation. Meanwhile, the POC stock increases while MAOC stock decreases in cropland under future climate scenarios. Our global estimation of POC and MAOC stock change under climate change highlights the importance of accounting for the different fractions of SOC, which provides new insights into combating climate change and implementing targeted measures.

Particulate organic carbon,Mineral-associated organic carbon,Global climate change