中文摘要：

尽管雪盖子在在高山带组织植物差异起一个重要作用，在雪盖子和东方 Qinghai 西藏的高原上的高山草甸的种类差异之间的关系上有很少研究。在高山草甸的植物种类差异上估计雪盖子的效果，我们使用了 60 m ×的十平行横断为这研究的 1 m 并且在与雪深度联系的种类差异和作文描述了变化。与进六个班的雪深度的部门，最高的种类丰富(S) 和种类差异(H′) 与中间的雪深度发生了，即，班 III 和班 IV，随雪深度的增加显示出一条单峰的曲线。在雪深度和植物差异(丰富和香农索引) 之间的关系能被二次的方程描绘。在差异(S 和 H′) 和土壤水分含量之间没有明显的关系，它暗示另外的更重要的因素影响了种类差异。在我们的学习发现的差异的模式大部分被归因于结冰融化改变，一些生长期和家畜放牧的骚乱。而且，雪深度影响了种类作文，由 Sørensen 类似的索引评估了。另外，限制到一个雪深度班的几乎所有种类仅仅在班 III 和班 IV 被发现，显示中间的雪深度对许多高山的种类的幸存和生长合适。

英文摘要：

Although snow cover plays an important role in structuring plant diversity in the alpine zone, there are few studies on the relationship between snow cover and species diversity of alpine meadows on the eastern Qinghai-Tibetan Plateau. To assess the effect of snow cover on plant species diversity of alpine meadows, we used ten parallel transects of 60 m × 1 m for this study and described the changes in species diversity and composition associated with snow depth. With the division of snow depth into six classes, the highest species richness （S） and species diversity （H′） occurred with an intermediate snow depth, i.e., class Ⅲ and class Ⅳ, showing a unimodal curve with the increase in snow depth. The relationship between snow depth and plant diversity （both richness and Shannon index） could be depicted by quadratic equations. There was no evident relationship between diversity （both S and H′） and soil water content, which implied that other more important factors influenced species diversity. The patterns of diversity found in our study were largely attributed to freeze-thaw alteration, length of growing season and disturbances of livestock grazing. Furthermore, snow depth affected species composition, as evaluated by the Sorensen＇s index of similarity. In addition, almost all species limited to one snow depth class were found only in class Ⅲand class Ⅳ, indicating that intermediate snow depth was suitable for the survival and growth of many alpine species.