森林与草地生态系统外生菌根呼吸与丛枝菌根呼吸对土壤呼吸的相对贡献及影响因子—基于数据整合分析OA

Mycorrhizal respiration(RMyc)significantly affects the carbon cycling in terrestrial ecosystems,yet its contribution potential and main influencing factors remain unclear.In this study,a meta-analysis was conducted by using 105 datasets from 41 publications.By employing a mesh exclusion method to distinguish soil respiration components,we quantified the average contribution of RMyc to soil autotrophic respiration(RAuto)and total soil res-piration(RT),and compared the differences between arbuscular mycorrhizal(AM)and ectomycorrhizal(ECM)contributions.The results showed that the average contribution rates of RMyc to RAuto and RT were 38.55%and 16.87%,respectively.Specifically,the average contributions of AM and ECM to RT were 16.78%(ranging from 2.48%to 32.00%)and 16.73%(ranging from 3.00%to 54.47%),respectively.Correlation analysis indicated that the RMyc rate was significantly negatively correlated with absolute longitude,mean annual precipita-tion,soil total nitrogen,and soil total phosphorus,while it was significantly positively correlated with soil pH and fine root biomass.Over all,RMyc is an important component of soil respiration,and is affected by environmental factors,soil nutrient supply,and symbiotic relationships.This study revealed the contribution of mycorrhizal res-piration to soil carbon fluxes at a global scale,providing a scientific basis for improving soil carbon cycle models.