Advanced   Register
XTBG OpenIR  > 西双版纳热带植物园毕业生学位论文  > 学位论文

title: 系统发育与功能维度的热带雨林树种个体生长和存活的邻体效应
Other Title: Phylogenetic and functional neighborhood effect on the survival and growth of woody species in a Chinese tropical rain forest
author: 乌俊杰
Advisor: 曹敏;  林露湘
Issued Date: 2016-11
Keyword: Janzen-Connell 假说;  系统发育距离;  环境过滤;  功能性状;  热带雨林
Major: 生态学
Abstract: 

树种的共存机制一直是群落生态学研究的核心问题之一。热带雨林具有丰富的树种多样性,生态学家提出各种假说和理论试图解释热带雨林群落的树种共存机制。两个或两个以上不同树种的个体在共同的时间和空间环境中的相互作用称为邻体效应。对邻体效应的研究有助于验证树种共存的相关假说和理论,还能够帮助进一步探讨群落构建的生态学机制。本研究以西双版纳20-ha 热带季节雨林动态样地(版纳大样地)内500 个2 m × 2 m 幼苗样方中的幼苗(高度大于或等于20 cm,基径小于1 cm)和所有成树(胸径大于等于1 cm)为研究对象,利用版纳大样地时间间隔5 年的2 次普查数据和幼苗样方时间间隔1 年的5次调查数据,从系统发育和功能性状的维度出发分析树种不同生活史阶段的个体生长和存活的邻体效应,探讨树种共存和群落构建的生态学机制。本研究获得以下两方面的结果:
1 环境过滤、同种负密度制约和系统发育密度制约对幼苗存活的影响
同种负密度制约机制(Janzen-Connell 假说)被认为是树种共存的重要机制之一。在此基础上,近年来,有研究发现幼苗个体的存活率随着邻体与其的系统发育相似性的升高而降低,形成系统发育负密度制约机制(Phylogenetic negative density dependence,PNDD)。然而同种邻体和与目标个体的系统发育距离较近的邻体对生境具有相同或相近的需求(环境过滤,Habitat filtering),会产生同种正密度制约和系统发育正密度制约(Phylogeneticpositive density dependence,PPDD),从而影响我们可观测到的同种负密度制约或系统发育负密度制约的强度和它们的可检测性。我们利用广义线性混合模型,通过分析影响10,000多株幼苗存活的邻体和环境因素,检测以上生态学机制在幼苗存活中的相对重要性。通过比较具有和不具有环境因子的模型,我们检测环境因子是否会影响同种负密度制约和系统发育负密度制约。最优模型表明同种负密度制约和环境是影响幼苗存活的重要因素,但我
们并没有发现系统发育负密度制约。环境因子会降低可检测到的同种负密度制约的强度,但对系统发育密度制约并没有显著影响。我们的结果表明在研究中忽略环境因子和系统发育密度制约会模糊同种和异种邻体对幼苗存活的作用。
2 环境过滤和邻体与目标个体间的功能性状相似性对成树存活与生长的影响
树种间功能性状的差异代表着对资源的需求和获取方式、生长和繁殖策略、忍受食草动物、病原菌和树种侵害的方式等方面的不同。树种间功能性状的相似程度是驱动群落功能组成和动态的重要因素。本研究要检验在树种的不同生活史阶段,邻体间的相互作用是否可以由邻体间的功能性状相似性来较好的预测出来。我们在不同的树木生长阶段建立了关于树木存活和生长的广义线性混合模型来估计功能性状相似性在影响邻体间相互作用中的相对重要性。我们共用到了版纳大样地内成树树种的11 种常用的功能性状数据。我们发现个体越大,存活率越高,生长率越低。邻体密度和依赖于功能性状相似性的邻体密度对个体存活没有显著影响。对于个体生长来说,邻体密度均表现负密度制约,依赖于功能性状相似性的邻体密度在小径级阶段有显著正作用,而到大径级阶段没有显著作用。我们的结果表明邻体间的相互作用会随着生长史阶段的不同而发生变化。
关键词:Janzen-Connell 假说;系统发育距离;环境过滤;功能性状;热带雨林

 

English Abstract: Species coexistence is a key issue in community ecology. Ecologists proposed many
hypotheses and theories to explain the coexistence of diverse tree species in tropical rain forests.Neighborhood effect refers to the interactions among coexisting individuals of different treespecies. The studies of neighborhood effect can reveal the mechanisms underlying communityassembly. The present study investigated the distribution of tree individuals at different life history stages in the 20-ha Xishuangbanna Forest Dynamics Plot (XSBN) in Mengla County,Xishuangbanna Dai Autonomous Prefecture, Yunnan Province, China. Two censuses for all
woody stems with basal diameter ≥ 1 cm were conducted in 2007 and 2012 respectively. 500 seedling quadrats (2 m × 2 m for each) were established in the plot and these seedlings in the quadrats were measured annually (for 5 times in total). By examing phylogenetic relatedness and functional similarity, we analyzed the neighborhood effect of the survival and growth of trees to explore ecological mechanisms underlying tree species coexistence and community assembly.
We got the following results of two aspects:
1 The effect of habitat filtering, conspecific negative density-dependence and phylogenetic
density dependence on seedling survival
Conspecific negative density-dependence (CNDD) is recognized as one of key mechanisms
underlying tree species coexistence. Some studies recently reported that seedling survival is also
negatively correlated with the phylogenetic similarity between neighbors and focal
individuals-termed phylogenetic negative density-dependence (PNDD). In contrast to CNDD or
PNDD, shared habitat requirements among conspecific or closely related individuals are thought
to be a cause of observed positive effects of conspecific or closely related neighbors, which may
affect the strength and detectability of CNDD or PNDD. In order to investigate the relative
importance of these mechanisms for tropical tree seedling survival, we used generalized linear
mixed models to analyze how the survival of more than 10,000 seedlings of woody plant species
related to neighborhood and habitat variables. By comparing models with and without habitat
variables, we tested how habitat filtering affected the detection of CNDD and PNDD. The
best-fitting model suggested that CNDD and habitat filtering played key roles in seedling
survival. While habitat filtering affected the detection of CNDD by reducing its apparent strength,
it did not explain the positive effects of closely-related neighbors. Our results demonstrate that a
failure to control for habitat variables and phylogenetic relationships may obscure the
importance of conspecific and heterospecific neighbor densities for seedling survival.
Degree Level: 博士
Place of Degree's Grantor: 北京
Grantor: 中国科学院研究生院
Content Type: 学位论文
URI: http://ir.xtbg.org.cn/handle/353005/10291
Appears in Collections:西双版纳热带植物园毕业生学位论文_学位论文

Files in This Item:

File SizeFormat
乌俊杰 博士学位论文.pdf2197KbAdobe PDFView  联系获取全文


全文许可: Creative Commons 署名-非商业性使用-相同方式共享 3.0

Recommended Citation:
乌俊杰. 系统发育与功能维度的热带雨林树种个体生长和存活的邻体效应[D]. 北京. 中国科学院研究生院. 2016.
Service
 Recommend this item
 Sava as my favorate item
 Show this item's statistics
 Export Endnote File
Google Scholar
 Similar articles in Google Scholar
 [乌俊杰]'s Articles
CSDL cross search
 Similar articles in CSDL Cross Search
 [乌俊杰]‘s Articles
Scirus search
 Similar articles in Scirus
Related Copyright Policies
Null
Social Bookmarking
  Add to CiteULike  Add to Connotea  Add to Del.icio.us  Add to Digg  Add to Reddit 
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Powered by CSpace