摘要
通过野外群落调查 ,分析了小五台山北坡植物物种多样性的垂直梯度变化。结果表明 :(1)小五台山北坡的物种丰富度随海拔的升高逐渐减小 ,物种组成趋于简单 ,乔木树种渐少。α多样性指数变化较小 ,但呈现出随海拔升高先增大、后减小的趋势。 (2 ) β多样性指数很好地反映了群落之间的变化。相异系数峰值出现在海拔 14 0 0 -15 0 0m处灌丛向森林的过渡带和海拔 2 6 0 0 - 2 70 0m处森林向亚高山草甸的过渡带。海拔 14 0 0 - 15 0 0m处出现的Cody指数极大值反映了灌丛群落向森林群落的变化 ,而Cody指数在海拔 2 10 0 - 2 2 0 0m的极大值反映了阔叶林和针叶林之间的过渡。 (3)作为小五台山两种最为重要的阔叶树种 ,白桦 (Betulaplatyphylla)和红桦 (Betulaal bo sinensis)沿海拔梯度出现明显的替代现象 ,随着海拔的升高 ,白桦逐渐为红桦所取代。
We analyzed patterns of plant species diversity along the northern slope of Mt. Xiaowutai based on 33 plots along an elevation gradient from 1250 m to 2850 m, at approximately 50 m intervals. Tree species richness decreased gradually with increasing elevation. However, α diversity index distributed along the altitudinal gradient in a unimodal pattern, i.e., α diversity peaked at the middle elevation. Changes in β diversity corresponded with the transition of vegetation types, i.e., β diversity peaked at the ecotones between different vegetation types. Both the community dissimilarity index and Cody index peaked at 1400-1500 m, 2100-2200 m, and 2600-2700 m, corresponding to the transitional zones of shrubs to forests, broad forests to coniferous forests, and forests to subalpine meadows, respectively. Altitudinal replacement of congeneric species was apparent for the two most important broadleaf tree species, white birch (Betula platyphylla) and red birch (Betula albo-sinensis). At lower elevations, the deciduous broad-leaved forest was dominated by white birch, which was replaced by red birch at higher elevations.
出处
《生物多样性》
CAS
CSCD
2004年第1期137-145,共9页
Biodiversity Science
基金
国家自然科学基金项目资助 (No .499710 0 2and 3 983 0 0 5 0 )
关键词
小五台山
北坡
垂直格局
物种多样性
植物
altitudinal pattern, Mt. Xiaowutai, northern slope, plant species diversity
