黄龙山白皮松林林隙物种多样性动态

运用Margalef丰富度指数（R）、Shannon-Wiener多样性指数（H′）、Pielou均匀度指数（Js）和生态优势度指数（λ）对黄龙山白皮松林不同大小和不同发育阶段林隙的物种多样性的动态规律进行了研究。结果表明:林隙中草本层、灌木层、乔木层植物的Shannon-Wiener多样性指数在Ⅲ级林隙（400~600 m²）时最大，随着林隙面积的增大，Shannon-Wiener多样性指数呈下降趋势，各生长型多样性指数在林隙发育的中前期（45~90 a）达到最大值，随着林隙年龄的增加而减少；草本层、灌木层和乔木层植物的Margalef丰富度指数和Pielou均匀度指数的变化趋势总体上与Shannon-Wiener多样性指数一致，生态优势度指数与Shannon-Wiener多样性指数几乎相反；乔木层植物的Shannon-Wiener多样性指数随林隙大小和年龄的变化趋势较灌木层和草本层植物变化缓慢，灌木和草本对林隙微生境的时空变化很敏感；R、H′、Js和λ在白皮松林不同大小和不同发育阶段林隙中表现显著性差异。

Gap Dynamics of Species Diversity in Pinus bungeana Forest in Huanglong Mountain

The dynamic patterns of the species diversity in gaps of different sizes and developmental stages in Pinus bungeana forest were studied by using Margalef richness index (R), Shannon-wiener index (H′), Pielou evenness index (Js) and ecological dominance index (λ). The results showed that the Shannon-Wiener indices of the herb, shrub and tree layers reached the highest in the conditions of gap gradient Ⅲ（400-600 m²） and the pro-metaphase of gaps (45-90 a), which declined with the increase of gap area and age. The general trend of R and Js were consistent with H′ in the herb, shrub and tree layers, while the ecological dominance index was opposite to H′. With the change trend of gap sizes and gap developmental stages, the Shannon-Wiener indices of tree layers were relatively slower than shrub and herb layers, which were very sensitive to the temporal-spatial changes in the gaps microhabitat; R, H′, Js and λ showed significant differences among different gap sizes and developmental stages.