四川老君山自然保护区常绿阔叶林群落结构特征与微地形分布

Community Structure and Microtopography Patterns of Evergreen Broad-Leaved Forest in Sichuan Laojunshan National Natural Reserve

采用样带与典型群落调查法对四川省老君山国家级自然保护区常绿阔叶林群落结构特征进行调查,并对其与微地形分布关系进行分析,结果表明:海拔、坡位、坡向、坡度等山地微地形条件对群落结构及物种分布影响显著.从山坡到山脊变化过程中,各样地平均高度、最大高度、平均胸径以及较大高度级和胸径级的物种个体比例减少,物种多样性也呈减小趋势,优势种逐渐突出.各样地之间物种组成存在显著差异(p<0.001),物种随地形因子表现出不同的空间分布,五爪槭(Acer oliverianum Pax)是海拔1480m左右山坡样地的优势树种,叶萼山矾(Symplocos phyllocalyx C.B.Clarke)是海拔1700m左右山脊样地优势树种.

Evergreen broad-leaved forest is widely distributed in the subtropical regions of China, and it plays a very important role in the global biological diversity and natural environment conservation also. In order to reveal community structure and micro topography patterns of evergreen broad-leaved forest in Laojunshan National Natural Reserve, Sichuan Province, six plots were set up from the slop to the ridge. The results showed that microtopographic factors including elevation, slope position, aspect and slope degree had a strong influence on community structure and species distribution. The mean height and DBH, maximum height, and the proportion of individuals belonging to larger height and DBH class decreased from the slop to the ridge, species diversity decreased gradually also. Species composition among various plots varied significantly （P 〈 0. 001 ）. The Acer oliverianum Pax is the dominant species on the slop plots, and the Symplocos phyllocalyx C. B. Clarke is the dominant species on the ridge plots.