青藏高原边缘区高寒草甸植物群落的特征

Features and plant diversity of alpine meadow communities in different edge regions of Qinghai-Tibetan Plateau

以甘肃天祝和玛曲为例,研究了青藏高原东北缘和东缘地区高寒草甸植物群落特征和多样性的分异性。结果显示,青藏高原东北缘和东缘地区高寒草甸植物群落的优势种均为高山嵩草(Kobresia pygmaea);东缘地区植物群落高度和盖度大于东北缘地区;植物群落均表现为双层垂直结构。东缘和东北缘地区高寒草甸植物群落的物种丰富度指数差异不显著(P>0.05);物种均匀度指数、α多样性指数、β多样性指数和地上生物量均表现为东缘地区显著大于东北缘地区。本研究结果说明,青藏高原周边地区高寒草甸群落特征、植物多样性和草地初级生产力具有较大分异性,因此,制订经营策略时应因地制宜,以维持高寒草甸的稳产和保育植物多样性。

A field survey in Maqu and Tianzhu Counties was conducted to determine the features and plant diversity of alpine meadow communities in northeast and east edge regions of Qinghai-Tibetan Plateau by calculating α and β diversity index and measuring community structure and aboveground biomass. Results showed that the dominant plants in the northeast and east regions were Korea capillifolia The community height and corerage in the east region were bigger than those of northeast regions. The vertical structure of alpine meadow was double layers in east and northeast regions. The richness index of alpine meadow com- munities and significantly difference between northeast region and east region,and evenness index of alpine meadow communities in east region was significantly bigger than that in the northeast region （P〈0. 05）. The diversity index of alpine meadow communities in east region was bigger than that in northeast regions. The β diversity index of alpine meadow communities in east region was significantly bigger than that in northeast region （P〈0.05）. The aboveground biomass of alpine meadow communities in east region was bigger than that in northeast region. This study indicated that the alpine meadow at the different regions showed an obvious differentiation in community features,plant diversity and primary productivity. It was suggested that grassland management measurements should be tailored by local requirement to maintain stable productivity and conserve the biodiversity of alpine meadow in Qinghai-Tibetan Plateau.