天童常绿阔叶林林窗对植物群落更新和物种多样性的影响

发布时间：2018-04-25 08:53

本文选题：林窗 + 非林窗　；参考：《华东师范大学》2017年硕士论文

【摘要】：林窗作为一种经常发生的小规模干扰,在维持森林群落的物种多样性、养分循环和群落结构的稳定上具有重要作用。林窗的出现会改变群落局部原有的环境,从而可能会引起不同生活型树种的更新发生变化,进而造成群落局部区域物种多样性的改变。在亚热带常绿阔叶林内,常绿树种与落叶树种广泛共存是该植被类型植物种类组成的重要特点之一。因此,在亚热带常绿阔叶林中研究林窗对常绿和落叶树种更新的影响,进而研究对物种多样性的影响,具有重要意义。本研究以浙江天童20ha森林动态监测样地为平台,对样地内149个冠林窗以及与其对应的非林窗进行跟踪调查。通过分析常绿树种和落叶树种的补员率与生长速率,以及林窗和非林窗的物种组成,用以探讨林窗对不同生活型树种更新的影响。利用随机取样的方法,使林窗与非林窗的植物个体密度相等,计算物种多样性指数,排除密度因素,分析林窗对物种多样性产生的影响。希望能够更加全面地了解林窗在植物群落中所起到的作用。本研究的主要结果如下:1、经过5年时间,林窗中落叶树种多度和重要值有所增加,且落叶树种的物种数增加较多;而非林窗的变化幅度则相对较小。加之,两次调查间,以及两次调查内林窗的Jaccard指数均显著小于非林窗,即林窗的物种组成,在时间和空间的变化幅度更大,说明林窗能够显著改变群落局部区域的物种组成,增加落叶树种的比例,促进常绿和落叶树种共存。2、林窗中常绿树种和落叶树种的补员率分别显著高于非林窗(p0.05),中林窗和大林窗中落叶树种的补员率分别为205.8%和269.15%,显著高于常绿树种的75.64%和82.26%(p0.05),而在非林窗中,常绿树种和落叶树种的补员率无显著差异。说明与非林窗相比,林窗促进了植物的更新,在林窗面积较大时,对落叶树种更新的促进作用大于常绿树种。林窗中常绿树种和落叶树种的生长速率分别为33.69%和144.34%,均显著高于非林窗的18.96%和20.36%(p0.01),且林窗中落叶树种的生长速率显著高于常绿树种(p0.01)。说明在本研究中,林窗有效地促进了植物的生长,尤其是促进了落叶树种的生长。3、2010年时林窗与非林窗的物种多样性不存在显著差异,且林窗内个体数相比于非林窗较少,说明2010年所调查的大部分林窗可能为刚形成的林窗。加之,2015年林窗的物种多样性均显著高于2010年(p0.05),而2015年非林窗的物种多样性与2010年不存在显著差异。说明在早期林窗中的物种多样性会随着时间的推进而显著增加。2015年时,大林窗的Inverse Simpson指数和Exp(H')显著大于非林窗(p0.05),说明当面积较大时,林窗能够增加局部区域物种多样性。综上所述,在亚热带常绿阔叶林中,林窗的形成,会增加落叶树种的补员率和生长速率,使得林窗中落叶树种的比例增加,进而改变了局部区域的物种组成,促进常绿和落叶树种的共存,增加了该区域的物种多样性。
[Abstract]:As a regular small scale interference, the forest window plays an important role in maintaining the species diversity, nutrient cycling and community structure stability in the forest community. The emergence of the forest window will change the local environment of the community, which may cause more new changes in the species of different species of life, and then cause the local regional species of the community. In the subtropical evergreen broad-leaved forest, the widespread coexistence of evergreen and deciduous trees is one of the important characteristics of the species composition of the vegetation type. Therefore, it is important to study the influence of the forest window on the evergreen and deciduous species regeneration in the subtropical evergreen broad-leaved forest and to study the effect on the species diversity. 149 canopy windows and its corresponding non forest windows in the 20ha forest dynamic monitoring site of Zhejiang Tiantong were tracked and investigated. By analyzing the rate and growth rate of the evergreen and deciduous trees, as well as the species composition of the forest window and the non forest window, the effects of the forest window on the regeneration of different living species were discussed. Using the method of random sampling to make the plant individual density of the forest window and the non forest window equal, calculate the species diversity index, exclude the density factor and analyze the effect of the forest window on the species diversity. We hope to understand the role of the forest window in the plant community more comprehensively. The main results of this study are as follows: 1, after 5 years, The number and important value of deciduous tree species in the forest window increased, and the number of species of deciduous trees increased more, but the variation of non forest windows was relatively small. In addition, the Jaccard index in the two investigations and the two surveys were significantly smaller than those of the non forest windows, that is, the species composition of the forest windows, which showed a greater change in time and space. The forest window can significantly change the species composition in the local area, increase the proportion of deciduous tree species and promote the coexistence of evergreen and deciduous tree species.2. The rate of the complement of evergreen and deciduous trees in the forest window is significantly higher than that of the non forest window (P0.05). The supplemental rate of the medium and Dalin window and the deciduous tree species in the middle and forest windows is 205.8% and 269.15% respectively, which is significantly higher than that of evergreen. 75.64% and 82.26% (P0.05) of tree species, but in the non forest window, there is no significant difference between evergreen and deciduous tree species. 33.69% and 144.34% were significantly higher than 18.96% and 20.36% of non forest windows (P0.01), and the growth rate of deciduous tree species in the forest window was significantly higher than that of evergreen tree species (P0.01). In this study, the forest window effectively promoted the growth of plants, especially in the growth of the growing tree species, which did not exist in the species diversity of the forest windows and the non forest windows at.32010 years. There were significant differences, and the number of individuals in the forest window was less than that of the non forest windows, indicating that most of the forest windows investigated in 2010 might be a newly formed forest window. In addition, the species diversity of the forest windows in 2015 was significantly higher than that in 2010 (P0.05), but the species diversity of the non forest windows in 2015 was not significantly different from that in 2010. The Inverse Simpson index and Exp (H') of Dalin window are significantly greater than that of non forest windows (P0.05) when the species diversity increases significantly with time, which indicates that when the area is larger, the forest window can increase the species diversity in the local area. In summary, the formation of the forest window in the subtropical evergreen broad-leaved forest will increase the rate of the filling of the deciduous trees. And the growth rate increases the proportion of deciduous tree species in the forest window, and then changes the species composition of the local region, promotes the coexistence of evergreen and deciduous species, and increases the species diversity in the region.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S718.5

【参考文献】