生物多样性 ›› 2021, Vol. 29 ›› Issue (9): 1186-1197.DOI: 10.17520/biods.2021205

• 研究报告:植物多样性 • 上一篇    下一篇

鼎湖山南亚热带常绿阔叶林植物功能性状变异与不同垂直层次个体生长的关联

李艳朋1,2, 倪云龙1,3, 许涵2, 练琚愉1,3,4,*(), 叶万辉1,3,4   

  1. 1.中国科学院华南植物园退化生态系统植被恢复与管理重点实验室, 广州 510650
    2.中国林业科学研究院热带林业研究所森林生态研究中心, 广州 510520
    3.中国科学院华南植物园广东省应用植物学重点实验室, 广州 510650
    4.南方海洋科学与工程广东省实验室(广州), 广州 511458
  • 收稿日期:2021-05-21 接受日期:2021-08-11 出版日期:2021-09-20 发布日期:2021-09-16
  • 通讯作者: 练琚愉
  • 作者简介:* E-mail: lianjy@scbg.ac.cn
  • 基金资助:
    中国科学院战略性先导科技专项(XDB31030000);国家重点研发计划(2017YFC0505802);中国森林生物多样性监测网络建设项目

Relationship between variation of plant functional traits and individual growth at different vertical layers in a subtropical evergreen broad-leaved forest of Dinghushan

Yanpeng Li1,2, Yunlong Ni1,3, Han Xu2, Juyu Lian1,3,4,*(), Wanhui Ye1,3,4   

  1. 1 Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650
    2 Forest Ecology Research Center, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520
    3 Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650
    4 Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458
  • Received:2021-05-21 Accepted:2021-08-11 Online:2021-09-20 Published:2021-09-16
  • Contact: Juyu Lian

摘要:

建立植物功能性状与群落动态之间的关联是功能生态学的核心问题之一。本文基于鼎湖山1.44 ha塔吊样地的两次调查数据, 通过采集样地内所有4,142株个体的6种植物功能性状, 对比分析了个体水平植物功能性状和物种水平功能性状均值对不同垂直层次(灌木层、亚冠层和林冠层)个体生长的影响差异。首先, 分析了不同垂直层次下各植物功能性状的变化趋势; 其次, 计算了不同垂直层次下各植物功能性状的种内和种间变异水平; 最后, 运用结构方程模型探讨了植物功能性状、光竞争以及地下竞争对不同垂直层次树木生长的影响。结果表明: (1)不同垂直层次下的植物功能性状表现出明显的分异, 由灌木层至林冠层, 叶面积、比叶面积和能量供求关系指数显著降低, 而叶片厚度和叶片干物质含量显著升高; (2)不同垂直层次下植物功能性状的种间变异均大于种内变异, 且林冠层的种内功能性状变异均大于灌木层和亚冠层; (3)基于个体水平植物功能性状的结构方程模型较物种水平功能性状均值对生长具有更高的解释程度, 且个体水平植物功能性状的引入更有利于提高对灌木层个体生长的预测能力; (4)光竞争和地下竞争主要通过影响功能性状间接影响植物生长。由灌木层至林冠层, 同种间的相互作用逐渐减弱, 异种间的相互作用逐渐增强。综上, 将个体水平植物功能性状纳入分析有助于更好地理解群落的结构和动态。

关键词: 垂直层次, 功能性状变异, 生物间的相互作用, 生长动态, 结构方程模型

Abstract

Aims: Establishing the relationship between plant functional traits and community dynamics is one of the core issues of functional ecology. Previous studies have found weak evidence of a relationship between functional traits and growth rate relationships in tree communities, highlighting the evidence that functional traits often fail to predict growth rate. It is therefore essential to advance a predictive approach to functional ecology. Since functional traits vary both among species and within species, linking functional traits at the individual level with plant growth will provide a path towards a more rigorous trait-based community ecology.
Methods: Based on the data from two survey of a 1.44-ha plot and the data of six plant functional traits from 4,142 individuals in Dinghushan, the effects of plant functional traits on plant growth were analyzed at the individual level and species level. First, the varied trends of different functional traits at different vertical layers (shrub layer, subcanopy layer and forest canopy layer) were explored. Second, the intraspecific and interspecific variations of each functional trait under different vertical layers were analyzed. Finally, the effects of plant functional traits, light competition and underground competition on tree growth were quantified using a structural equation model.
Results: Results suggest that: (1) Plant functional traits at different vertical layers exhibited significant differentiation. From the shrub layer to the canopy layer, leaf area (LA), specific leaf area (SLA) and energy supply-demand index (R) decreased significantly, while leaf thickness (LT) and leaf dry matter content (LDMC) increased significantly. (2) The interspecific variation of plant functional traits at different vertical layers is greater than the intraspecific variation, and the intraspecific variation of functional traits in the canopy layer is greater than that in the shrub layer and subcanopy layer. (3) The structural equation model based on plant functional traits at an individual level produces a higher degree of explanation for growth than at the species level. Furthermore, the introduction of plant functional traits at the individual level is more conducive to improving the ability to predict individual growth at the shrub layer. (4) Light competition and underground competition indirectly affect plant growth by affecting functional traits. From the shrub layer to the canopy layer, the interactions between conspecific individual gradually weakened and the interactions between different species gradually increased.
Conclusion: Our study highlights that analyzing plant functional traits at an individual level could help to better understand plant community structure and dynamics.

Key words: vertical layer, variation of functional trait, biotic interactions, growth dynamic, structural equation model