作 者 ：何中声, 刘金福, 郑世群, 洪伟, 吴则焰, 徐道炜, 吴承祯
期 刊 ：植物科学学报 2012年 30卷 2期 页码：133-140
Keywords:Castanopsis kawakamii, Forest gap, Species diversity, Stability,
摘 要 ：采用物种多样性指数和改进的M. Godron稳定性法研究林窗干扰对格氏栲(Castanopsis kawakamii)自然保护区天然林更新层物种多样性和稳定性的影响。结果表明:林窗干扰改善了微环境,表现在林窗和林下乔灌层树种重要值和多样性存在差异。林窗乔木层中丰富度指数R、优势度指数D、Shannon-Wiener指数H、均优多指数Z均高于林下,均匀度指数Js和群落优势度指数C低于林下;灌木层中R、D、H、Js、Z指数均高于林下,群落优势度指数C低于林下,林窗物种多样性更为丰富,生态优势种不明显,群落向复杂化和均匀化方向发展。林窗与林下乔木层Jaccard相似性系数Cj、Sorenson相似性系数Cs、Bray-Curtis指数CN相对较低,Morista-Horn指数CmH较高,林窗对树种更新具有促进作用;灌木层相似性系数Cj、Cs、CN、CmH均较高,物种组成基本一致。根据M.Godron稳定性原理拟合出稳定性模型,林窗和林下乔木层分别为对数模型与二次函数模型,林窗和林下灌木层最佳拟合模型均为对数模型。林窗乔木层植物处于稳定状态,林下乔木层植物不稳定;林窗和林下灌木层植物均处于稳定状态。林窗和林下乔木层树种中以桂北木姜子(Litsea subcoriacea)重要值最高,说明其在森林更新中占有重要地位,可能对格氏栲种群更新产生较大影响。林下乔木层中格氏栲重要值较低,格氏栲更新存在困难,而林窗干扰促进了格氏栲的向上生长和重要值的提升,可有效实现格氏栲种群的更新和恢复。
Abstract:The effect of forest gap disturbance on the diversity and stability of species in the regeneration layers of natural Castanopsis kawakamii forest were studied by applying biodiversity indices and improved M.Godron’s stability methods in C.kawakamii natural reserve.The results showed that: forest gap disturbance improved its micro-environment,as reflected in the differences in importance values and biodiversity in the tree and shrub layers of forest gap and understory.The biodiversity indices of richness index R,domination index D,Shannon-Wiener diversity index H,and evenness-dominance-abundance index Z in the forest gap tree layer were higher than those of the forest understory,while evenness index Js and community domi- nance C were lower than those of the forest understory.The biodiversity indices of R, D, H, Js, and Z in the forest gap shrub layer were higher than those of the forest understory,while C were lower than those of forest understory.Biodiversity in the forest gap was richer with less evident ecological dominant species,which indicated that the population in the forest gap was developing in the direction of complexity and homogeneity.The similarity coefficients of Cj, Cs, and CN were relatively low,while CmH was relatively high in the tree layer of the forest gap and understory,which demonstrated that the forest gap promoted the regeneration of trees.The similarity coefficients of Cj, Cs, CN, and CmH were relatively high without exception and the species composition in the forest gap were basically identical with those of the understory.According to the theory of M.Godron and the simulated the optimum stability model,the logarithm model and quadratic objective function model were the best stability models in tree layer of the forest gap and understory, respectively,and the optimum stability model of the shrub layer in both the forest gap and understory was the logarithm model.The plants in the tree layer of the forest gap were stable,but were unstable in the understory.The plants in the shrub layer of both the forest gap and understory were stable.The importance value of Litsea subcoriacea was the highest in the tree layer of the forest gap and understory,which showed that it played an important role in forest regeneration and would likely have a greater impact on the regeneration of C.kawakamii population.The importance value of C.kawakamii was relatively low in the tree layer of the forest understory,which impacted its regeneration.However,forest gap di-sturbance improved the upward growth and importance value of C.kawakamii,which could achieve the regeneration and restoration of the C.kawakamii population effectively.
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