Abstract:

The paper aims to explore the influence of topography on the pattern of vegetation on landscape scale. Based on the investigation of a large number of forest communities at Dalaoling Mountain in the Three Gorges, 7 indexes were used to figure out the topographical characteristics of habitats. The topographical pattern of different communities were analyzed with detrended canonical correspondence analysis (DCCA) ordination, and the influence of topographical factors, spatial factors and their interaction on the total variance of vegetative pattern were quantitatively partitioned. The results suggested that, the contribution of the 3 aspects is 9.50%, 5.94% and 6.81%, respectively. Topography shows dominant controlling effect on the vegetative pattern at Dalaoling. But 77.75% of the variance were not interpreted yet.

三峡大老岭森林物种多样性的空间格局分析及其地形解释
沈泽昊^1,2  张新时²  金义兴³

（1.  北京大学城市与环境学系，北京100871；2. 中国科学院植物研究所，北京100093；
3. 中国科学院武汉植物研究所，武汉430074)）

摘要：在对三峡大老岭地区森林的大量群落样方调查基础上 ,研究地形因子和取样尺度对群落不同层次α多样性水平及其空间格局的影响 ,结果表明 :①受地形、人为或自然干扰的影响 ,大老岭森林群落的α多样性存在海拔10 0 0m以下、海拔 110 0～ 170 0m和海拔 170 0m以上 3段不同的水平与变化特征 ;②对海拔 10 0 0m以上样方群落的 16种多样性指数的DCCA分析表明 ,群落乔、灌、草各层的多样性在多维地形因子梯度上表现出不同的格局 ;③本地地形因子对群落α多样性格局影响的大小顺序是 :坡位 海拔 坡向 坡面 坡度 坡形。④对海拔 10 5 0m和 16 70m处两个样方α多样性的多尺度对比分析表明 :高、低海拔的群落不同层次α多样性水平及其变化在各个尺度上差别明显。总之 ,地形对山地森林植物物种多样性格局显示了多方面和多尺度的影响 ;α多样性的海拔梯度格局在此未得到确证。

关键词： 三峡大老岭；α多样性；格局；地形

Key words: Dalaoling in the Three Gorges, spatial pattern of vegetation, topographic interpretation, canonical correspondence analysis, ordination