Abstract:

The traits and biodiversity of alpine grassland community at different habitats (terraces, north-facing slope, ridges, south-facing slope) were investigated and evaluated in the Zhuaxixiulong Township of Tianzhu County, Gansu Province. The effects of habitat factors on grassland productivities were explored in order to provide an evidence for the rational use of different grassland habitats. Results showed that the number of species was no significantly different, whereas the community structures of the grasslands differed significantly between mid- and late-growing seasons at the same habitat. The coverage of vegetation in terraces and north-facing slop was higher than that in south-facing slope, and the vegetation coverage differed significantly between ridge and north-facing slop at the end of July (P<0.05). The aboveground biomasses of grasslands differed significantly between different tested habitats except ridges and south-facing slope in early September (P<0.05). The number of species, Margelef index and Shannon-Wiener index of grassland vegetation were ordered as terraces

Key words: Alpine grassland, Habitat types, Biodiversity, Jaccard similarity

摘要：

对甘肃省天祝藏族自治县抓喜秀龙乡境内不同生境条件下（阶地、阴坡、山脊、阳坡）高寒草甸草原生长季中期、末期的草地植被状况进行调查究，并进行生物多样性评价，旨在探寻生境因子对草地生产力的影响，为不同生境草地合理利用提供依据。结果表明：相同生境下草地植被在生长季中期和末期物种数量差异不显著，但其群落结构差异显著。植被盖度为阳坡<山脊<阶地<阴坡，阶地与阴坡盖度均显著高于阳坡（P<0.05），7月底山脊盖度与阴坡差异显著（P<0.05）；地上生物量为山脊<阳坡<阶地<阴坡，其中样地间除9月初山脊与阳坡生物量差异不显著外，其余均差异显著（P<0.05）。同一时期不同生境条件下植被物种数目、群落物种丰富度Margelef指数、物种多样性Shannon-Wiener指数均为阶地<阳坡<山脊<阴坡，各生境间群落均匀度Pielou指数变化规律不明显，可能不适用于高寒草地的评价。植被群落相似性系数差异变化表明生境对草地群落组成结构的影响显著。

关键词: 高寒草地, 生境类型, 生物多样性, 相似性