长白山北坡植物群落间物种共有度的海拔梯度变化

应用梯度格局法在长白山北坡海拔700-2600 m之间每100 m设置一样地,共计20块样地,应用Jaccard指数,对植物群落间物种共有度的海拔梯度变化进行了分析。不同海拔群落间的共有度,无论以哪一层次的植物种来表达,基本都以与其最相邻海拔的群落之间为最高。相邻海拔群落的不同层次物种间的共有度变化存在相似性和相异性;但如相邻海拔的两个群落属于不同植被类型,其共有度则较低。群落间物种共有度的峰值与谷点反映了植被的海拔梯度格局,且灌木种的物种更替在这些地段具有非常明显的规律。在同一海拔差群落间的共有度数值都非常接近,并均随着海拔差的增加呈明显的下降趋势,表明群落各层次物种的构成有很大的相关性。

The changes of co-possession of plant species between communities with altitudes on northern slope of Changbai Mountain

Twenty plots were investigated on northern slope of Changbai Mountain at an attitude interval of 100 m (from 700 to 2600 m). The species co-possession between plant communities at different altitudes was analyzed by Jaccard index. The analytical results showed that the co-possession calculated according to species in different layers or all species between adjacent communities was higher than that between disjunct communities. The co-possessions between adjacent communities calculated by species in different layers had comparability and dissimilarity. If the two adjacent communities belong to different types of vegetation, then their co-possession was lower. The peak values and valley values of species co-possession between communities along elevation gradient just matched vegetation gradient patterns, and species subrogation of shrubs had more obvious rule on northern slope of Changbai Mountain. Co-possessions between communities with same altitude difference were much similar, and it decreased as the increase of elevation difference, which showed that species compositions in different layers of the communities were highly related.