Abstract: Due to the fragile nature of Qinghai-Tibet plateau,the productivity and diversity of alpine plant communities are extremely sensitive to climate change. At present,it is unclear how the alpine meadow diversity and productivity response to the climate change. In this study,the open top growth chambers (OTCs) was used to simulate the warming. By studying the changes of plant community species diversity and primary productivity in the alpine Stipa purpurea meadow ecosystem,the response of the alpine meadow to the warming effect was discussed. The results showed that:1) The temperature increase had a significant effect on the important values of some species in the alpine meadow (P<0.05),the Shannon-Wiener diversity index decreased significantly (P<0.05),the species richness index decreased significantly (P<0.05),and the total primary productivity of the community did not change significantly;2) There was no simple linear relationship between species diversity and primary productivity. The warming treatment made the soil water scarcity,which led to the weakening of the correlation between species diversity and primary productivity.

Key words: Qinghai-Tibet Plateau, Warming, Species diversity, Aboveground biomass, Vegetation change

摘要： 青藏高原因其环境脆弱的特征，高寒植物群落生产力和多样性对气候变化的响应极其敏感。当前，关于高寒针茅化草甸多样性和生产力对气候变化做出何种应答还不明确。本研究利用开顶气室法（Open top growth chambers，OTCs）进行模拟增温，通过研究高寒针茅化草甸生态系统植物群落物种多样性和初级生产力的变化，探讨高寒针茅化草甸对增温效应的响应。研究结果表明：1）温度升高对高寒针茅化草甸部分物种的重要值产生显著影响（P<0.05），群落Shannon-Wiener多样性指数显著下降（P<0.05），物种丰富度指数显著下降（P<0.05），群落的总初级生产力变化不显著；2）物种多样性与初级生产力之间不是简单的线性关系。因此，增温处理使得土壤水资源匮乏，导致物种多样性与初级生产力的相关性减弱。

关键词: 青藏高原, 增温, 物种多样性, 地上生物量, 植被变化