Microbial necromass carbon (C) is a crucial soil organic carbon (SOC) component. In the context of alpine grassland degradation on the Qinghai-Tibet Plateau, the establishment of artificial grasslands is an effective restoration method; however, the accumulation of microbial necromass C and its contribution to SOC in these ecosystems, especially for the different plant species composition, remain unclear. We collected surface soil (0-10 cm) from artificial grasslands of four different types in 2022, including annual unicast Triticale and annual grass-legume mixed artificial grasslands sown last time in 2022, and perennial Elymus nutans and perennial Poa pratensis artificial grasslands sown in 2019. By measuring soil moisture and pH value, contents of amino sugars, and microbial biomass (MB) characteristics, we aimed to investigate the variations in microbial necromass C and its contribution to SOC and identify the factors influencing these processes. The content of microbial necromass C followed the order: perennial Elymus nutans > perennial Poa pratensis > annual grass-legume mixed > annual unicast Triticale. This was mainly because belowground biomass indirectly affected microbial necromass C by altering soil properties. The ratio of MB C/N and soil moisture were identified as the primary factors influencing the contribution of microbial necromass C to SOC. The contribution of microbial necromass C to SOC was more favorable under perennial grasslands with a low MBC/MBN ratio and high SWC than under annual grasslands. Thus, from the perspective of microbial necromass accumulation, perennial grasslands were the most suitable vegetation type for sustainable soil restoration.

微生物坏死物碳 (C) 是土壤有机碳 (SOC) 的重要组成部分。在青藏高原高寒草地退化的背景下，建立人工草地是一种有效的恢复方法；然而，微生物坏死物 C 的积累及其对这些生态系统中 SOC 的贡献，特别是对于不同植物物种的组成，仍不清楚。我们收集了 2022 年 4 个不同类型人工草地的表土（0-10 cm），包括 2022 年播种的一年生单播小黑麦和一年生草豆混合人工草地，以及 2022 年播种的多年生披碱草和多年生早熟禾人工草地。 2019.通过测量土壤湿度和pH值、氨基糖含量和微生物生物量（MB）特征，旨在研究微生物坏死物C的变化及其对SOC的贡献，并确定影响这些过程的因素。微生物坏死物C的含量顺序为：多年生披碱草>多年生早熟禾>一年生草豆混合>一年生单播小黑麦。这主要是因为地下生物量通过改变土壤性质间接影响微生物坏死物C。MB C/N 比和土壤湿度被确定为影响微生物坏死物 C 对 SOC 贡献的主要因素。在MBC/MBN比值低、SWC高的多年生草地上，微生物坏死物C对SOC的贡献比一年生草地更有利。因此，从微生物坏死物积累的角度来看，多年生草地是最适合可持续土壤恢复的植被类型。