Plant litter-derived dissolved compounds leaching is an important process for soil carbon (C) sequestration and nutrient cycling. However, knowledge of the biotic and abiotic drivers of dissolved compound release from litter mixture remains limited. Here, we evaluated the loss of soluble C, N, and P during litter mixtures decomposition across an alpine treeline ecotone, and we sought to assess the relative importance of environmental conditions, litter diversity (functional dissimilarity (Rao) and community-weighted mean (CWM) traits), litter chemistry (C quality, nutrients, and stoichiometry) and microbe drive dissolved compound release during the decomposition process. The results showed that dissolved compound release from litter mixtures deviated from predictions based on litter monoculture, with predominantly synergistic effects, and the hierarchical drivers suggested: temperature strongly regulated the release of dissolved compounds and its non-additivity. In particular, freeze-thaw cycles and seasonal snow accelerated the synergistic effects on dissolved compound loss. Litter CWM and Rao traits only accelerated soluble C release and the synergistic effects of soluble P at the last stage of dissolved compound loss, respectively. Litter nutrients directly drove the release of soluble C and P at different stages. Litter C quality and microbes regulated the release of soluble C and P via direct effects, and stoichiometry had an indirect impact, which mainly before 40 % of initial mass loss. Yet, litter chemistry showed a minimal effect on soluble N release, so controls established for the release of soluble C and P might not be valid for soluble N during decomposition. Collectively, our findings advocate the decomposition environment and litter nutrients are key factors for controlling the dissolved compounds leaching, then followed by the interactions of litter C quality, stoichiometry, litter functional diversity, and microbe, which is important for understanding soil organic matter pool and soil fertility in alpine ecosystems.

来自植物凋落物的溶解化合物的浸出是土壤碳（C）隔离和养分循环的重要过程。然而，关于溶解化合物从垫料混合物中释放的生物和非生物驱动因素的知识仍然有限。在这里，我们评估了整个高山乔木过渡带凋落物混合物分解过程中可溶性C，N和P的损失，并试图评估环境条件，凋落物多样性（功能差异（Rao）和社区加权平均值（ CWM）性状，垫料化学性质（C品质，养分和化学计量）和微生物驱动分解过程中溶解的化合物释放。结果表明，凋落物混合物中溶解的化合物的释放与基于凋落物单一培养的预测不同，主要起协同作用，并提出了层次驱动因素：温度强烈调节溶解的化合物的释放及其非可加性。特别是，冻融循环和季节性降雪加速了对溶解化合物损失的协同作用。凋落物的CWM和Rao性状分别仅加速了可溶性C的释放以及可溶性P在溶解的化合物损失的最后阶段的协同作用。凋落的养分直接推动了可溶性碳和磷在不同阶段的释放。凋落物C的质量和微生物通过直接作用来调节可溶性C和P的释放，化学计量学具有间接影响，主要是在初始质量损失40％之前。然而，凋落物化学显示出对可溶性N释放的影响最小，因此为释放可溶性C和P而建立的控制对于分解过程中的可溶性N可能无效。