Abstract: Rhizosphere was a special micro-ecological system,which was important for understanding the interactions between soil and plant communities. The present study aims to investigate the distribution of nutrient and microbial biomass in rhizosphere soil and non-rhizosphere soil during degraded alpine meadow,and the correlation and difference of rhizosphere nutrient enrichment in dominant degraded grassland. The results showed that the microbial biomass C,N,P and nutrient content in rhizosphere soil were significantly higher than those in non-rhizosphere soil under different degrees of degradation (P<0.05). And increased with the degree of degradation decreased gradually;with the degree of degradation of alpine meadow,the carbon of rhizosphere microbial biomass,Nitrogen,phosphorus and nutrients all have nutrient enrichment effects,and their enrichment rates were severely degraded grassland > moderately degraded grassland > lightly degraded grassland > non-degraded grassland. Correlation showed that there was a significant positive correlation between MBC,MBN and TP,TN and SOC in rhizosphere and non-rhizosphere soil (P<0.01).The above results show that the effective nutrients of soil in the process of grassland degradation were enriched in the rhizosphere of plants,and the activation phenomenon,which is of great significance for people to further understand and regulate the nutrient cycle of the rhizosphere.

Key words: Alpine meadow, Rhizosphere and non-rhizosphere soil, Soil nutrients, Soil microbial biomass, Rhizosphere enrichment rate

摘要： 根际是一类特殊的微生态系统，对研究土壤与植物群落间的相互作用具有重要意义。本研究旨在探讨高寒草甸退化过程中根际与非根际土壤的养分和微生物量分布特征，以及优势植物根际养分富集的相关性和差异性。结果表明：不同退化程度条件下，根际土壤中微生物量碳、氮、磷和养分含量显著高于非根际土壤（P<0.05），且随退化程度加剧呈逐渐下降趋势；随高寒草甸退化程度的加剧，根际微生物量的碳、氮、磷和养分均出现富集效应，其富集率表现为重度退化草地 > 中度退化草地 > 轻度退化草地 > 未退化草地；由相关分析可知，根际与非根际土壤中微生物量碳和微生物量氮与全磷、全氮和有机碳之间均呈极显著正相关关系（P<0.01）。综上所述，草地退化过程中土壤的有效养分和微生物量在植物根际存在富集和活化现象，这对于人们进一步认识和调控根际的养分循环具有重要意义。

关键词: 高寒草甸, 根际土壤, 土壤养分, 土壤微生物量, 根际富集率