摘要
用 7个指标反映三峡大老岭地区森林群落生境的地形特征 ,采用 DCCA排序方法定量分析不同地形因子对亚热带山地森林植被格局的影响及它们各自的生态意义 ;并分析它们的作用强度沿海拔的变化。结果表明 :1)DCCA排序的前 4个轴分别与海拔、坡位和坡度、坡向和坡面显著相关 ;山地森林植被存在多重尺度和方向的分异格局 ;2 )山地森林群落样方生境的热量、水分 (养分 )和光照条件可主要由海拔、坡位和坡度、坡向等地形特征分别反映 ;3)在垂直梯度上 :海拔的影响在海拔 6 0 0～ 80 0 m和 15 0 0～ 170 0 m最大 ;坡向影响的峰值在山顶带 ;坡度、坡位与坡形的影响在山地中部影响最大 ,其中坡度在海拔 6 0 0 m以下的影响也很显著 ;坡面的影响在山地中部最显著。
Seven indices were used to define the topographical characteristics of community habitats in mountain forest at Dalaoling in the Three Gorges region.Based on th at, a DCCA was used to quantitatively analyze the ecological roles of the topogr aphical parameters and their effects on the spatial patterns of subtropical moun tain forest communities; the altitudinal variations of their effects were also a nalyzed.The results suggest that: 1) the first 4 axes of DCCA are prominently ass ociated with elevation,position and slope exposure,and mountain aspect respectively; multi-scal e and directional multi-differentiation patterns were found in this mountain forest vegetation; 2) the temperature,moisture,nutrient and illumi nation conditions of the sampling habitats of the mountain forest communities ar e reflected by the topographical factors elevation,slope, position and exposure; 3) on the vertical gradient: the influence of elevat ion on vegetation was s trong at 600-800 m and 1500-1700 m; and that of exposure had the strongest effect on vegetation composition at the summit zone of the mountain; the slope ,position and shape of slope showed prominent effects in mid-slope regions,unde r 600 m the effect of slope angle was also strong; the effect of aspect was stro ngest in midslope regions.
出处
《植物生态学报》
CAS
CSCD
北大核心
2000年第4期430-435,共6页
Chinese Journal of Plant Ecology
基金
中国科学院植物研究所植被数量生态开放实验室基金!( L P95 0 9)
