山西庞泉沟银露梅群落物种多样性的海拔格局

采用样地调查的方法, 对山西庞泉沟银露梅(Potentilla glabra)群落的结构特征、物种多样性随海拔梯度的变化以及沿海拔梯度群落的相似性进行了研究, 并通过R语言对群落α多样性指数间的相关性进行了分析。结果表明: (1) 银露梅群落各层的α多样性指数除生态优势度指数(D)沿海拔梯度的变化不明显外, 其它各指数的变化基本一致。银露梅群落在海拔 1 700-1 900 m与2 100-2 300 m区间内, 灌木层和草本层的α多样性指数均较高, 在海拔1 900-2 000 m区间则较低。另外, 银露梅群落各α多样性指数间除J₂外均呈显著正相关。(2) 随着海拔间隔的增加, 灌木层和草本层的4个β多样性指数的变化均呈上升趋势, 并且草本层随海拔间隔的增加β多样性指数整体比灌木层高。(3) 银露梅群落Jaccard相似性指数随着海拔间隔的增大逐渐减小, 而当海拔达到2 300 m以上时, 群落间的相似性升高, 群落相对稳定。

Elevational Patterns of Community Species Diversity of Potentilla glabra in Pangquangou of Shanxi Province

We used the sample-plot survey method to examine the structural characteristics of the Potentilla glabra community; we analyzed the change in species diversity with changing altitude gradient and the similarity of the community along the altitude gradient, and the association between diversity indexes of the community. (1) At the same elevation gradient, the diversity index for community α showed the herb layer greater than the shrub layer. The ecological dominance index (D) did not differ by elevation gradient, and other indexes were basically consistent. The P. glabra community appeared between 1 700-1 900 m and 2 100-2 300 m, where the diversity index of the shrub and herb layers was higher, with lower index at 1 900-2 000 m. In addition, except for the J₂, all diversity indexes showed significant positive correlation. (2) With increasing altitude, the 4 diversity indexes for community β for the shrub and herb layers increased with increasing altitude; the diversity index was higher for the herb than shrub layer on the whole. (3) With increasing altitude, the Jaccard similarity index decreased. However, with sea level > 2 300 m, the similarity between communities increased and the community was relatively stable.