海南尖峰岭热带林乔灌木层物种多样性沿海拔梯度分布格局

Elevation Patterns of Tree and Shrub Species Diversity of Tropical Forests in Jianfengling,Hainan Island

沿海南尖峰岭林区海拔梯度设立164块25m×25m样地,分析乔灌木层物种多样性沿海拔梯度的变化规律,同时分析森林采伐对这种分布格局的影响。结果表明:尖峰岭物种丰富,164块625m2样地共记录植株65144个,分属84科253属596种;原始林的物种丰富度沿海拔梯度呈现双峰型的分布格局,主要受尖峰岭地区水热、光照、群落特性等因素控制;径级择伐后森林物种丰富度沿海拔梯度波动上升;皆伐后森林物种丰富度随着海拔梯度剧烈波动;原始林的Simpson物种多样性指数随海拔增高而缓慢上升;径级择伐森林Simpson物种多样性指数首先随海拔增高而平缓上升,海拔800m处最高,之后缓慢下降;皆伐林中Simpson物种多样性指数随海拔增高先上升,海拔680m处达到一个峰值,然后下降,海拔850m处又开始继续上升;和原始林相比较,径级择伐森林总体而言沿海拔梯度的Simpson物种多样性指数有所上升,而皆伐森林的Simpson物种多样性指数有所下降。

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.