不同干扰类型对高寒草甸群落结构和植物多样性的影响  

The influence of disturbance on community structure and plant diversity of alpine meadow

作　　者：江小蕾 张卫国[2] 杨振宇 王刚[1] 

机构地区：[1]兰州大学干旱农业生态国家重点实验室,兰州730000 [2]兰州大学草地农业科技学院,兰州730020 [3]甘肃省玛曲县畜牧局,甘肃玛曲747300

出　　处：《西北植物学报》2003年第9期1479-1485,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家重点基础研究发展规划项(G2000018600)资助

摘　　要：对高寒草甸天然草地进行了施肥、围栏和放牧 中牧和重牧 处理,研究不同干扰类型对草地植物多样性的影响.结果表明,施肥使草地植物群落物种组成贫乏,群落结构趋于简单,物种多样性减少;中等程度放牧增加了群落结构的复杂性,丰富度指数和多样性指数均最高,支持 中度干扰理论 ;重度放牧,由于干扰过于剧烈而减少了物种优势度和多样性;而轻度干扰的围栏草地,群落由少数优势种所统治,多样性也不高.物种数 S 、丰富度指数 Ma 、Shannon-Wiener指数 H' 、Simpson指数 D 的排列顺序均为:施肥草地<围栏草地<重牧草地<中牧草地;均匀度指数 Jsw 的变化趋势与上述各指数相同;优势度指数的变化趋势则相反,为施肥草地>围栏草地>重牧草地>中牧草地.4种干扰类型草地群落的生活型功能群基本一致,均由多年生禾草、多年生杂类草和莎草类组成,但各功能群在群落中所占比重及各功能群内所含物种数则大不相同.说明不同干扰类型对草地植物群落的物种组成、多样性格局及系统功能等方面产生不同的影响.The main purpose of this study was to examine the effects of disturbance nutrient addition, enclosure,(middle and heavy) grazing on community structure, plant diversity, and functional group. The results showed that nutrientaddition leads to a decrease in species diversity; middle grazing increases the complexity of plant community and plant diversity, supporting the hypothesis of intermediate disturbance; heavy grazing, because of it serious influence on plant community, results in a low richness and diversity index; while enclosure, the light disturbance, with the community dominated by few species, have lower diversity too. The five diversity indices (species number, richness index, ShannonWiener index, Simpson index and evenness index) changes in an increasing order, as follows: nutrient addition < enclosure < heavy grazing < middle grazing.However,the dominance shows a reverse trend. The plant species within four disturbance communities were classified into functional groups based on the differences in life form. Although the four communities had the similar functional groups,which all was composed of perennial grasses, perennial forbs and sedges, the proportion of each group in different community and the species diversity within the functional groups are quite different. This result suggests that the type of disturbance had different effect on species compositions, diversity patterns and ecosystem functioning in alpine meadow pasture. 

关 键 词：高寒草甸 干扰 群落结构 植物多样性 

分 类 号：Q948.158[生物学—植物学] S812-05[农业科学—草业科学]