东灵山亚高山草甸物种多样性变化及其影响因子

应用丰富度指数(R)、Simpson指数(λ)、Shannon-Weiner指数(H′)和均匀度指数(E1)研究了北京东灵山亚高山草甸7个群丛的植物种多样性.结果表明:由于生境不同群丛类型各异,进而导致各个指数在不同群丛间的变化.R和H′随海拔高度增加而下降,E1则随海拔升高而呈上升趋势.在旅游和放牧的双重干扰下,R和H′随干扰强度的增加而降低,E1则相反.旅游和放牧使物种向均匀化方向发展,同时促进了适口性差、耐践踏和伴人植物种类的生长.

CHANGES IN SPECIES DIVERSITY AND CONTRIBUTING FACTORS IN SUBALPINE MEADOWS IN DONGLING MOUNTAIN

Diversity in plant species in 7 associations in subalpine meadows on Dongling Mountain is studied using richness index (R), Simpson index (λ), Shannon- Weiner index (H') and evenness index (E_1), respectively. The results show that bcause of the different habitats of different types of association, which leads to variation of every index among different associations. The R and H' declines with increasing elevation.E_1 increase with mounting elevation. With the disturbing of traveling and grazing, the R and H' decrease with increasing disturbance degree, the E_1 of contrast. Tourism and grazing enable species to develop in the direction of uniformity, at the same time promoting growth of species unfit to eat, endurable to trample, and humanaccompanying.