放牧干扰对祁连山高寒金露梅灌丛草甸群落的影响  

Effect of grazing disturbance on plant community of alpine meadow dominated by Potentilla froticosa shrub on Qilian Mountain

作　　者：盛海彦[1] 曹广民[2] 李国荣[1] 周靖靖[2] 焦文月[1] 李吉鹏[1] 张平[1] 

机构地区：[1]青海大学,青海西宁810003 [2]中国科学院西北高原生物研究所,青海西宁810001

出　　处：《生态环境学报》2009年第1期235-241,共7页Ecology and Environmental Sciences

基　　金：中国生态网络台站项目(2006);教育部“新世纪优秀人才支持计划”项目(NCET-04-G983)

摘　　要：以祁连山北支冷龙岭东段南麓的甘柴滩夏季牧场集体长期混合(藏系绵羊、牦牛)放牧的高寒金露梅Potentilla froticosa灌丛草场为对象,利用空间分布代替时间演替的方法,采用方格网法取样分析调查,对不同放牧压力梯度下金露梅灌丛群落的结构、组成、物种多样性、地上生物量进行研究,结果表明:①放牧居住点由远到近,放牧压力梯度不断增加,金露梅株高、密度、覆盖度、地上生物量和丛间草地的地上生物量均有不同程度的降低,地上的总生物量降低幅度达84.77%。金露梅株高与放牧压力梯度遵循对数方程;而金露梅密度、覆盖度、丛间草本地上生物量与放牧压力梯度呈幂函数关系。②随着放牧压力梯度断增加,金露梅灌丛下层群落的物种组成及其结构有显著变化。禾本科、莎草科和杂类草植物的地上生物量均有不同程度的下降,而杂类草的地上生物量占地上草本植物总生物量的比例由56.0%上升到79.69%;莎草科生物量占地上草本植物总生物量的比例略有所上升;禾本科的地上生物量占草本植物地上总生物量的比例由31.2%下降到9.6%。This study was carried out in collective-owned summer grassland in Ganchaitan, which is located at the south foot of eastern Lenglongling Mountain （a branch of north Qilian Mountain）, with yak and Tibetan sheep miscellaneously grazed on it. The grassland type could be classified as alpine meadow, dominated by Potentilla froticosa shrub （PFS）. This study, under grads grazing stress, focused on the community structure, composition, species diversity, above-ground biomass of PFS, by using pane net sampling based on spatial distribution in stead of temporal succession. Results showed that： Grazing stress negatively related to the distance between grazing area and resident area. The height, density, coverage, above-ground biomass of PFS, and the above-ground biomass of vegetation amongst PFS were increased with the grazing distance. Total above-ground biomass in resident area decreased 84.77%, compared to that in remote area. There are relationship of logarithmic function between the height of PFS and the grazing distance. There are exponential function relationship of grazing distance to the density, coverage and above-ground biomass of vegetation of PFS, ②The species composition and structure of the lower community of PFS were also affected by grazing stress. With the increasing of grazing stress, the hierarchy of community structure and the above-ground biomass of grasses, sedges and forbs decreased, while the biomass percentage of forbs and sedges increased （from 56% to 79.69% for forbs biomass, and a little bit increase for sedges biomass）. Grasses biomass took 31.2% of the total above-ground biomass at low grazing stress, and it decreased to 9.6% of the total above-ground biomass at high grazing stress.

关 键 词：金露梅灌丛 放牧干扰 群落 

分 类 号：Q948[生物学—植物学]