甘肃小陇山锐齿栎群落生物多样性特征分析

Analysis of biodiversity characteristics of Quercus aliena var. acuteserrata community on Mt.Xiaolong in Gansu

生物多样性是当前群落生态学研究的一个重要方面。为此,选择了地处我国南北交界的秦岭西段北坡——甘肃小陇山的锐齿栎群落作为研究对象,经过大量野外实地调查和室内数据分析,认为:(1)研究区锐齿栎群落乔木层物种多样性测度结果为:平均物种多样性指数H=1.483,平均均匀度指数Jsw=0.67,平均丰富度指数R=9。这与亚热带常绿阔叶林和暖温带阔叶落叶林相比较,具有明显的过渡性特征;(2)乔木层物种多样性沿海拔梯度在阴、阳坡存在两种不同的分布模式。在阳坡,物种多样性沿海拔梯度呈直线上升分布模式;在阴坡,物种多样性对海拔梯度呈不很敏感的分布模式,对阴、阳坡进行对比,阴坡多样性、均匀度和丰富度均大于阳坡,优势度相反;(3)经过采伐干扰,恢复20年后,与保护区相比,乔木层物种丰富度有所增大,多样性和优势度有所降低,均匀度没有产生明显变化。

The paper chooses Quercus aliena var. acuteserrata community as research material which lies on north aspect of western Qinling mountain.We make conclusions through plenty of wild investigations and inside analysis as the follow: (1) The average species diversity index ( H ) is 1.483;the average evenness index ( Jsw ) is 0.67 and the average richness index ( R ) is 9 in tree layer,it shows obviously transition comparing with the subtropical forest and the temperate forest.(2) There are two distributed patterns of species diversity along the elevation gradient.The species diversity increases with the elevation gradient,it shows the linear model on sunny slope facing;the species diversity have no obviously relationship with elevation on shade exposure.There are bigger diversity,evenness and richness on shade slope facing than that of on the sunny slope facing,the dominance shows inverse pattern to that of the diversity.(3) The species richness in tree layer increases,the diversity and the dominance decrease,the evenness have no change after 20 years recovered since it was disturbed comparing to that of protected region in same community.