澜沧江上游德钦县亚高山、高山草地群落类型及其特点

Community Types and Their Features of Alpine and Subalpine Meadow on Deqin County of Southeastern Tibetan Plateau

采用样方调查方法获得 94个草地群落样方 ,对澜沧江上游德钦县亚高山、高山草地群落类型及其特点进行了初步分析。结果表明 ,该县亚高山、高山草地群落类型存在 2 0个类型。在放牧干扰下 ,大多数群落类型处于退化状态 ,相互之间存在明显的群落替代关系 ;调查发现群落中每平方米内平均含 8种草本植物 ,平均盖度 6 2 .4% ,地上平均生物量是 485 9kg hm2 ,平均可食率为 6 1.5 % ;鸢尾群落、牛旁群落和小狼毒群落是草地严重退化后形成的典型有毒害群落类型 ;长期的高强度放牧虽然增加了群落类型多样性 ,但减少了群落内物种多样性。总体而言 ,长期的放牧干扰降低了德钦草地的生物多样性的质量及其生态服务功能 。

The study was conducted in Deqin County in the northeastern Yunnan Province in an effort to understand the present situation of the subalpine and alpine meadow. Community plot method was employed. 94 plots were investigated and their species composition, community coverage, and community structure were examined. The types and features of subalpine and alpine meadow were analyzed. The results displayed there are at least 20 community types of meadow existing in subalpine and alpine region of the Deqin County. Most types were on the way of degradation and obvious interactive substitution was found among those communities. Iris japonica community, Actium lappa community, and Stellera chamaejasme community were the most typical and poisonous types formed under the situation of meadow degradation seriously. There was average 8 species existing in one square meter and average coverage was 62.4%. The aboveground biomass was 4859 kg/hm 2 and average edible rate was 61.5%. An important finding is that the long_term high_intensity grazing increased community diversity but decreased species diversity in a community. Totally speaking the long term grazing regime existing lowered the value and ecological services of biodiversity in Deqin County, contributing to unsustainable development of alpine and subalpine meadow ecosystems.