Abstract
The impact of global warming on soil carbon cycling has become a core issue in climate change research. As a critical flux of carbon exchange between terrestrial ecosystems and the atmosphere, soil CO2 emissions have profound implications for the global carbon budget and climate change. However, the response mechanisms of soil CO2 emissions to warming in different ecosystems remain unclear. Using a meta-analysis approach, this study systematically integrated 380 publications, covering 265 research sites and 620 datasets, to investigate the response characteristics of soil CO2 emissions to warming and their key driving factors. Results showed that soil CO2 emissions exhibited a significant positive response under global warming, with notable variations in response intensity among different ecosystems. Forest ecosystems showed the strongest response, followed by agricultural and grassland ecosystems. Annual mean temperature, precipitation, and soil moisture were identified as the primary environmental factors driving soil CO2 emissions, exerting significant positive effects, while factors such as altitude showed negative impacts. Moreover, the dynamic changes in soil CO2 emissions were influenced by direct temperature increases and soil properties and ecosystem types. This study provides an important theoretical basis for understanding the spatiotemporal variations of soil CO2 emissions under global warming while offering critical data support and scientific insights for evaluating and managing soil carbon sink functions and predicting future climate change.
