茂兰喀斯特森林林隙物种多样性的动态规律

Study on Dynamic Pattern of Species Diversity in Gaps of Karst Forest in Maolan Natural Reserve,Guizhou Province

分析了茂兰喀斯特森林不同大小和发育阶段林隙物种多样性的动态变化规律。结果表明:林隙中乔木、灌木、草本和藤本植物的多样性指数H′在140～210 m2时最大,随林隙面积的进一步扩大,H′呈下降趋势。乔木、灌木和草本的多样性指数H′在林隙形成的20～30 a间达最大值,随林隙年龄的增加而减小。藤本植物的多样性指数H′在林隙形成初期至40 a时逐渐增加,在40 a时达最大值,最大值出现时间较其他生长型滞后。各生长型物种丰富度指数R1和均匀度指数J的变化趋势总体上与物种多样性指数相一致,生态优势度λ值与物种多样性指数几乎相反。乔木和藤本植物的多样性指数随林隙大小和年龄的变化趋势较灌木和草本植物和缓,灌木和草本植物对林隙环境的时空变化最为敏感。

The change pattern of species diversity of different growth forms in gaps of different sizes and developmental stages in Maolan Karst forest was measured and analyzed by means of Marglef index, Shannon-Wiener index, Pielou index and Simpson index. The results showed that the species diversity index （Shannon-Wiener） of arbor, shrub, herb and liana reached the highest in gap size of 140 -210 m2, and decreased with gap size being larger. The species diversity index of arbor, shrub and herb reached the highest in the gap age of 20 - 30 years, and decreased with gap age. The species diversity index of liana increased gradually with gap development and reached the highest in 40 years. The highest value appeared much later than those of other growth forms. The general trends of species richness index of different growth forms were correspondent with those of species diversity index, and species evenness index were in opposite to those of ecological dominance index. Species diversity index of arbor and liana did not change much more significant than those of shrub and herb with change of gap size and gap age. Shrub and herb were much sensitive to temporal and spatial environmental change of gaps.