陆地生态系统土壤CO2排放对模拟增温的响应特征及影响因素OA北大核心CHSSCDCSTPCD

Global warming has become an indisputable fact.The research on the carbon cycle of terrestrial ecosystems has received extensive attention from all walks of life and is a key topic in current global change research.Soil CO2 emission is one of the largest fluxes of CO2 exchange between terrestrial ecosystems and the atmosphere,and how soil CO2 emission in terrestrial ecosystems respond to global warming and its influencing factors remains unclear,which limits the in-depth understanding of soil carbon cycle processes and influencing mechanisms.This study aims to clarify the patterns and influencing factors of soil CO2 emission in terrestrial ecosystems under global warming.Based on the Chinese and English journal databases such as Web of Science,PubMed and CNKI,81 peer-reviewed papers was collected worldwide,65 research sites and 213 sets of relevant research data were extracted.We used Meta-analysis to explore the response of soil CO2 emission in terrestrial ecosystems to simulated warming,and analyzed its correlation with altitude,climate,soil water content,bulk density(BD),pH,soil total nitrogen(TN),and soil organic carbon(SOC).The results showed an overall significantly positive response of soil CO2 emission to simulated warming in terrestrial ecosystems,with+13.1%,+18.0%,and+5.9%(P＜0.05)in agricultural,forest,and grass ecosystems,respectively.Forest ecosystems showed the strongest positive response to the simulated warming.Warming can promote soil respiration for a short period of time,but with the increase of warming duration,the sensitivity of soil respiration to temperature will be reduced,and the adaptability to temperature changes will be weakened,thereby the response of soil respiration to warming will be weakened.The response are affected by environmental factors,soil characteristics and other experimental conditions,and the most conditions show significant positive response to warming,and different influencing factors interact and influence each other.Warming generally alters plant biomass,soil nutrient content,microbial quantity and activity,thus affecting vegetation rhizosphere respiration and soil respiration rates.Correlation analysis showed that elevation had significantly negative effect on soil CO2 emission,while mean annual temperature,mean annual precipitation,soil water content,and depth of instrument embedded in soil had significantly positive effects on soil CO2 emission.These results have important implications for understanding the spatial and temporal patterns of global soil carbon emissions,and provide a theoretical basis for accurately evaluating the function of soil carbon sinks and their persistence in the context of global warming.