资源环境科技发展态势分析平台

Tree species associated with different mycorrhizal fungi play a crucial role in the carbon (C) cycling of forest ecosystems, while their effects on soil respiration (R-S) and the underlying mechanisms remain uncertain. In this study, we used a common garden experiment that included five monocultures (two arbuscular mycorrhizal - (AM) and three ectomycorrhizal-associated (ECM) temperate tree species) to explore the effects of mycorrhizal associations on the R-S and the driving factors. Our specific objectives were to (1) compare the R-S between the AM and ECM stands, and (2) explore the driving factors of the R-S. We found that the R-S in the AM stands was significantly greater (34.3%) than that in the ECM stands. The R-S was significantly and positively correlated with microbial biomass C (C-mic), fine roots biomass (B-root), or soil water content (W-5), but negatively with forest floor mass (F-mass) or soil dissolved organic C content (C-dis). The best-fitted models of R-S explained 46.3%, 38.3%, and 45.4% of the variations in the R-S for the AM stands, the ECM stands, and the combined dataset, respectively. However, the factors contributing to the R-S varied with mycorrhizal groups. The R-S of the AM stands was mainly influenced by C-mic, B-root, root C/N ratio, F-mass, and C-dis, whereas the R-S of the ECM stands was mainly affected by litter C/N ratio, C-dis, soil dissolved nitrogen content, soil temperature and W-5. These findings highlight the significance of shifts in AM or ECM tree abundance due to forest management and global change in forest C cycling.