Abstract: The relationship between the diversity of tree and shrub species and the altitudinal gradient of Jianfengling was analyzed based on 164 25 m×25 m quadrats. We also analyzed the impacts of forest logging on the altitudinal patterns of tree and shrub species. Results showed that Jianfengling had abundant plant species. There were 65 144 individuals and 596 species in the 164 quadrats, which belong to 84 families and 253 genera. In the primary forests, the distribution of species richness along the altitudinal gradient showed a bimodal pattern, which was mainly controlled by the water, heat, light and community characteristics in Jianfengling. Species richness had an undulate increase along the altitudinal gradient in the diameter-limit logged forests but changed dramatically in the clear-cut forests. On the other hand, in the primary forests, Simpson species diversity index increased gradually along the altitudinal gradient. In the diameter-limit logged forests, it maintained a slow increase, but had a decline trend after 800 m. In clear-cut forests, it increased gradually along the elevation before 680 m and then declined until it rose again at 850 m. Furthermore, Simpson species diversity index increased after diameter-limit logging and decreased after clear-cutting by comparing with the primary forests along the altitudinal gradient.

Key words: species diversity, altitudinal gradient, diameter-limit logging, clear-cutting, Jianfengling