本研究基于巴里坤县国家级山地草原监测站10 a植物群落观测数据，探究了长期不同放牧管理方式（长期禁牧M0、冬季放牧M1和全年放牧M2）对新疆山地草原植物群落特征值、植物多样性及多样性与地上生物量之间关系的影响。结果表明：M0、M1和M2对优势种沙生针茅重要值无显著影响，M1和M2提高了非优势及草地退化的指示物种芨芨草、醉马草的重要值；随着放牧强度的增加，群落高度、盖度、密度、地上生物量及其响应比显著下降；Shannon-Wiener多样性指数、Simpson优势度指数和Pielou均匀度指数在各放牧处理下均无显著差异，但Margalef丰富度指数随放牧强度显著增加；M0处理地上生物量与Simpson优势度指数、Shannon-Wiener多样性指数和Pielou均匀度指数负相关，M1处理地上生物量与Margalef丰富度指数负相关。随着处理时间的增加，长期禁牧有利于退化草地的恢复，提高了群落特征值，在一定程度上有利于草地生产力的提高和群落稳定性的维持；放牧会影响生态系统中资源的再分配，导致物种多样性的增加，但是全年放牧管理方式下草地则退化加剧。

Mountain grassland are an essential component of pasture resources in the Xinjiang Uygur Autonomous Region. However, mountain grassland are highly vulnerable to human-associated disturbance and climate change. The responses of the mountain grassland plant community characteristics and diversity to different grazing managements in Barkol County, Xinjiang, are still unclear. In this study, three different grazing management treatments were set up in 2012 to investigate the response patterns of the plant community characteristics, diversity, and the relationship between the diversity and the aboveground biomass in the mountain grasslands. The three grazing management blocks were M0, M1, and M2, which represented the permanent grazing prohibition, winter grazing, and year-round grazing management, respectively. During the peak growing seasons of 2013, 2017, and 2022, the data regarding the number of species, height, coverage, density, and aboveground plant biomass were collected for further analysis. The results indicated that the different grazing managements had no significant impacts on the importance value of the dominant species, such as Stipa glareosa. However, the importance values of the nondominant species such as Neotrinia splendens and Achnatherum inebrians (Hance) Keng increased under winter and year-round grazing. As grazing intensity increased, plant height, coverage, density, aboveground biomass, and their response ratios declined significantly (P<0.05). There were no significant differences in the Shannon-Wiener diversity, Simpson dominance, and Pielou evenness indices in M0, M1, and M2. In contrast, the Margalef richness index elevated markedly (P<0.05), indicating that grazing provided more survival resources helpful for other species. In the permanent grazing prohibition block, the aboveground biomass was negatively correlated with the Simpson dominance, Shannon-Wiener diversity, and Pielou evenness indices. In the winter grazing block, aboveground biomass was negatively correlated with the Margalef richness index. Overall, the importance value of the dominant species showed no remarkable differences under varying grazing management, and its dominance remained unchanged. Except for the Margalef richness index, the other diversity indices were not significantly influenced by grazing. Winter and year-round grazing enhanced the vital value of unpalatable species, altering the composition of forage, which was not conducive to future animal husbandry development. In summary, as the enclosure time increased, permanent grazing prohibition was beneficial for restoring degraded grasslands, improving community characteristic values, improving grassland productivity, and maintaining community stability to a certain extent. Grazing would affect resource redistribution in the ecosystem, releasing ecological niches for more species, but year-round grazing led to intensified grassland degradation because of overgrazing pressure.