【摘要】 通过对青藏高原东缘高寒草甸生态系统 8个草地类型植物群落样地定位监测资料进行结构特征及物种多样性分析研究 ,结果表明 ,青藏高原东缘高寒草甸草地草群盖度大、物种丰富 ,但大多数草地多样性随退化程度的加重而降低 ,优良牧草所占比例不高 ,总的反映出退化演替的趋势 ,超载、鼠虫危害、人为干扰以及全球气候变化等因素是草地退化的主要原因。从群落结构特征来看 ,不同类型群落演替阶段依次为原生植被 (Ⅵ、Ⅶ )、轻度退化 (Ⅰ、Ⅲ、Ⅳ、Ⅴ )、重度退化 (Ⅱ、Ⅷ ) ;群落物种丰富度指数 (S)依次为Ⅲ >Ⅴ >Ⅵ >Ⅶ >Ⅰ >Ⅳ >Ⅱ >Ⅷ ;物种多样性指数依次为Ⅵ >Ⅴ >Ⅶ >Ⅲ >Ⅰ >Ⅱ >Ⅷ >Ⅳ ,表现出原生植被的物种多样性指数明显高于不同退化程度的群落类型。因此 ,加大力度保护高原生态环境 ,尽快遏制草地退化趋势应为当务之急更多还原

【Abstract】 Through analysis and study of the data of the location observation on the structural feature and species diversity on the 8 types of grassland of the alpinemeadow ecosystem in the eastern edge of the Qinghai Tibetan Plateau, the result showed that the plant coverage was well and the species was rich on the alpine meadow type of grassland in the plateau. However, the diversity and the ratio of good quality grass were low on the most grassland. It indicated that the trends of degradation succession, which resulted mainly from overgrazing, pest, human interference and the global climate change etc. In the community structural feature, the succession stages of the community were original vegetation (Ⅵ,Ⅶ), slight degradation (Ⅰ,Ⅲ,Ⅳ,Ⅴ) and heavy degradation (Ⅱ,Ⅷ) successively. The richness index of species in the community (S) wereⅢ>Ⅴ>Ⅵ>Ⅶ>Ⅰ>Ⅳ>Ⅱ>Ⅷ successively. The species diversity index wereⅥ>Ⅴ>Ⅶ>Ⅲ>Ⅰ>Ⅱ>Ⅷ>Ⅳsuccessively, indicating that the species diversity index of the original vegetation was obviously higher than that of degraded communities. Therefore, it is a pressing task at present to enhance the protection of highland environment so as to stop grassland degradation as soon as possible.更多还原