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武夷山脉是我国大陆东南生物多样性最为富集的关键地区,其主峰黄岗山西北坡具有典型的垂直带谱。为探讨其植物物种多样性沿海拔梯度的变化特征,依植被类型于黄岗山西北坡设置5个海拔梯度(900~2000 m,从低到高分别记为海拔梯度1、2、3、4、5),采用α和β多样性指数进行评估。结果显示:随海拔的上升,样地物种的平均科数、平均属数、平均种数和乔木的平均株数及其种数均呈下降的趋势,且海拔梯度1与海拔梯度3、4及5均呈显著性差异(P<0.05)。群落α多样性指数在海拔梯度上呈减小的变化趋势,其中Gleason丰富度指数海拔梯度间差异性与物种平均种数一致,Shannon多样性指数只有海拔梯度1与海拔梯度5间呈显著性差异(P<0.05),Pielou均匀度指数则差异不显著。而群落β多样性指数和物种平均密度在海拔梯度上呈先减小后增大的“V”型变化。乔木的多样性指数未表现出与群落多样性指数相同的变化趋势,但其Pielou均匀度指数在海拔梯度上的差异性表现一致。综合物种多样性和植物密度结果表明:低海拔梯度的植被群落具有较高的物种多样性,中海拔梯度的植物密度最低。
Wuyishan Mountains is the key area where the southeast China’s biodiversity is most abundant. Its main peak, Huanggang Mountain, has a typical vertical band spectrum. In order to explore the variation characteristics of plant species diversity along the altitudinal gradient, five altitudinal gradients (900-2000 m) were set up on the northwestern part of Huanggang Mountain according to vegetation types, and recorded as altitude gradient 1, 2, 3, 4, 5), using alpha and beta diversity indices for evaluation. The results showed that with the elevation increasing, the average number of families, the average number of genus, the average number of species and the average number of trees and the number of trees in the sample plots all showed a decreasing trend. And the altitude gradient 1 and the altitude gradient 3, 4 and 5 All showed significant difference (P <0.05). The diversity index of community α showed a decreasing trend at the altitude gradient. The difference of the Gleason abundance index in the altitude gradient was the same as that of the species. The Shannon’s diversity index was only significant between the altitude gradient 1 and the altitude gradient 5 (P <0.05), Pielou evenness index was not significantly different. However, the community β diversity index and species mean density decreased first and then increased at the altitudinal gradient. The diversity index of arbors did not show the same trend as the community diversity index, but the Pielou evenness index showed the same performance in altitude gradient. The results of comprehensive species diversity and plant density show that the plant communities with low altitude gradient have higher species diversity and the plants with mid-altitude gradient have the lowest density.