燕山山脉天然次生油松林群落物种多样性及生态位分析

The analysis of community structure,species diversity and niche of natural secondary Pinus tabulaeformis Carr. stand in Yanshan moutains

通过植物群落学的调查方法,对位于冀北山地河北省围场县木兰围场自然保护区内不同立地条件下油松(Pinus tabulaeformis Carr.)天然次生林的群落特征、物种多样性及物种生态位进行了研究。结果表明:在木兰围场自然保护区内共记录到乔木树种1种,灌木6种,草本30种。灌木层和草本层的α多样性指数在一定海拔梯度下所呈现的趋势大致相同,都是比较典型的双峰曲线。随着海拔差的增大,群落间β多样性指数均呈逐渐增大的趋势。灌木层中土庄绣线菊(Spiraea pubescens Turcz.)的生态位宽度最大,草本层中披针苔草(Carex lanceolata Boott)、林地早熟禾(Poa nemoralis Linn.)和小红菊[(Dendranthema chanetii(Lvl.)Shih)]的生态位宽度最大。海拔1125m地段生态位重叠度最大的种群为照山白(Rhododendron micranthum Turcz.)和女娄菜(Melandrium apricum(Turcz.)Rohrb.),海拔1250m地段生态位重叠度最大的种群为细裂叶蒿(Artemisia tanace-tifolia Linn.)和阴地蒿(Artemisia sylvatica Maxim.),海拔1325m地段生态位重叠度最大的种群为披针苔草和隐子草(Cleistogenes caespitosa Keng)。

On the basis of investigation data from 3 plots of natrual secondary forests at different altitudinal gradients in the Mulan Weiehang Nature Reserve in Hebei province. Studies regarding characteristics of species diversity were conducted, important values of plant species in each layer were measured, and richness, evenness and diversity indices of species in each layer were estimated by means of many methods. Futhermore, niche breadth and niche overlap of main species were al- so calculated. The result showed that layers of communities and dominant species in each layer were obvious in natural sec- ondary forests in Mulan Weiehang Nature Reserve in Hebei province. In terms of important values, dominant species in tree layer was Pinus tabulaeformis Cart.. Dominant species in shrub layer were Spiraea pubescens Turcz. and Rhododendron mi- cranthum Turcz.. Dominant species in herb layer were Carex/anceohaa Boott and Poa nemoralis Linn. The changes of a species diversity of shrub layer and herb layer along altitudinal change were mainly the tmimodal model. Diversity index in- creased when the distance was high between the cormnunities. The greatest niche breadth was found for species of Spiraea pu- bescens Turcz. and Carex lanceolata Boott; The community which had largest niche overlap at low altitude was Rhododen- dron micranthum Turcz. And Melandrium apricum （ Turcz. ） Rohrb., the commnity was Artemisia tanacetifolia Linn. and Ar- temisia sylvatica Maxim. at middle altitude, the community was Carex lanceolata Boott and Cleistogenes caespitosa Keng at high altitude.