Soil respiration (R_S) is the largest terrestrial carbon (C) flux to the atmosphere, and it can be influenced by changing input of plant C from above- and/or below ground. Especially in tropical and sub-tropical ecosystems, the contributions of litter respiration (R_L), autotrophic respiration (R_A) and mineral soil respiration (R_M) are still poorly understood. In the present study, R_S was measured under untreated control (CT), root exclusion (NR), litterfall exclusion (NL), and combined litterfall and root exclusion (NRNL) in a subtropical Cunninghamia lanceolata plantation and a secondary Castanopsis carlesii forest for three years. In addition, litter input, litter and soil chemistry, and microbial biomass and community structure (PLFAs) were assessed. R_S was significantly higher in the C. carlesii forest than in the coniferous C. lanceolata forest. R_L and R_A were significantly higher in the C. carlesii forest than in the C. lanceolata forest, while there was no significant difference in R_M. R_M, R_A, and R_L contributed 55%, 29%, and 16% to R_S under C. lanceolata, and 39%, 32%, and 29% under C. carlesii, respectively. Above ground litter input and microbial biomass were lower in the coniferous C. lanceolata forest. Soil microbial biomass was significantly lower in NL, NR and NRNL in both forests. NL had most pronounced effects on the microbial community composition in the C. carlesii soil, whereas NR and NRNL affected the community composition in C. lanceolata soil. Overall, the unexpectedly small and only insignificant additive effects of litter exclusion and root exclusion in the combined treatment (NRNL) suggest that yet unresolved interactions had accelerated the decomposition of mineral soil organic matter and R_M under this lowest plant C-input scenario. Hence, in the case that above and below ground plant C inputs change simultaneously, effects on R_S and its components might be more complex than suggested by single-C-source manipulation studies.

土壤呼吸 (R _S ) 是最大的陆地碳 (C) 流向大气，它会受到来自地上和/或地下的植物 C 输入变化的影响。特别是在热带和亚热带生态系统中，凋落物呼吸（R _L）、自养呼吸（R _A）和矿质土壤呼吸（R _M）的贡献仍知之甚少。在本研究中，在亚热带杉木人工林和次生卡氏栲中，在未处理对照 (CT)、根排斥 (NR)、凋落物排斥 (NL) 以及凋落物和根排斥联合 (NRNL) 下测量了R _S森林三年。此外，还评估了凋落物输入、凋落物和土壤化学以及微生物生物量和群落结构 (PLFA)。C. carlesii森林中的R _S显着高于针叶C. lanceolata森林。C. carlesii森林中的R _L和 R _A显着高于C. lanceolata森林，而 R _M没有显着差异。R _M、R _A和 R _L对C. lanceolata下的R _S贡献了 55%、29% 和 16%，在C. lanceolata下贡献了39%、32% 和 29%C. carlesii，分别。针叶树C. lanceolata森林的地上凋落物输入和微生物生物量较低。两个森林中 NL、NR 和 NRNL 的土壤微生物生物量显着降低。NL 对C. carlesii土壤中的微生物群落组成影响最显着，而 NR 和 NRNL 影响C. lanceolata土壤中的微生物群落组成。总体而言，在联合处理（NRNL）中，凋落物排除和根排除的意外小且仅微不足道的附加效应表明尚未解决的相互作用加速了矿质土壤有机质和 R _M的分解在这种最低的工厂 C 输入情景下。因此，在地上和地下植物 C 输入同时变化的情况下，对 R _S及其成分的影响可能比单 C 源操纵研究所建议的更复杂。