生物多样性 ›› 2023, Vol. 31 ›› Issue (2): 22139.  DOI: 10.17520/biods.2022139

• 研究报告: 植物多样性 • 上一篇    下一篇

亚热带常绿阔叶林林分结构对物种组成变异的驱动作用: 从局域到区域尺度

杨欣1,2, 姚志良2,3, 王彬2,4, 温韩东2,5, 邓云2,6, 曹敏2,5, 张志明4, 谭正洪1,4,*(), 林露湘2,6,*()   

  1. 1.海南大学生态与环境学院, 海口 570228
    2.中国科学院西双版纳热带植物园热带森林生态学重点实验室, 昆明 650223
    3.中国科学院大学, 北京 100049
    4.云南大学生态与环境学院暨云南省高原山地生态与退化环境修复重点实验室, 昆明 650091
    5.云南哀牢山森林生态系统国家野外科学观测研究站, 云南景东 676209
    6.云南西双版纳森林生态系统国家野外科学观测研究站, 云南勐腊 666303
  • 收稿日期:2022-03-29 接受日期:2022-05-25 出版日期:2023-02-20 发布日期:2022-06-23
  • 通讯作者: *谭正洪, E-mail: tan@ynu.edu.cn;林露湘 linluxa@xtbg.ac.cn
  • 基金资助:
    中国科学院战略性先导科技专项(B类)(XDB31030201)

Driving effects of forest stand structure of a subtropical evergreen broad-leaved forest on species composition variation: From local to regional scales

Xin Yang1,2, Zhiliang Yao2,3, Bin Wang2,4, Handong Wen2,5, Yun Deng2,6, Min Cao2,5, Zhiming Zhang4, Zhenghong Tan1,4,*(), Luxiang Lin2,6,*()   

  1. 1. School of Ecology and Environment, Hainan University, Haikou 570228
    2. CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223
    3. University of Chinese Academy of Sciences, Beijing 100049
    4. School of Ecology and Environmental Sciences & Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Yunnan University, Kunming 650091
    5. National Forest Ecosystem Research Station at Ailaoshan, Jingdong, Yunnan 676209
    6. National Forest Ecosystem Research Station at Xishuangbanna, Mengla, Yunnan 666303

摘要:

林分结构可以表征森林群落光的可利用性和光环境的异质性, 对群落物种组成的变异具有重要驱动作用。然而, 目前还鲜有研究将林分结构用于解释群落物种组成的变异。本研究以哀牢山亚热带中山湿性常绿阔叶林20 ha森林动态监测样地及其周边区域按公里网格设置的19个1 ha森林动态样地为研究对象, 将林分结构参数、环境因子和空间结构变量共同作为解释变量, 采用基于冗余分析的变差分解和层次分割方法, 在局域和区域尺度上同时解析群落物种组成变异的驱动因素。结果表明, 在局域和区域尺度上, 纳入林分结构后均提高了对物种组成变异的解释率。在局域尺度上, 加入林分结构作为解释变量后, 单纯的空间结构的解释率明显下降, 林分结构与环境因子累计贡献了41.0%的解释率。在区域尺度上, 林分结构与环境因子累计贡献了23.0%的解释率。从局域到区域尺度, 环境过滤的相对作用明显增强。林分结构指示的光的可利用性对林冠下方的树种组成具有较强的塑造作用, 今后的研究应进一步探讨林分结构对亚热带常绿阔叶林物种组成变异的驱动机制。

关键词: 林分结构, 尺度效应, 激光雷达, 光的可利用性, 哀牢山

Abstract

Aim: The variation of species composition can be partitioned into two components which are explained by environment and space, and can be used to further explore the niche process and neutral process of community assembly. Forest stand structure characterizes the light availability and heterogeneity under forest canopies, and it is a major driving factor in the variation of species composition for forest communities. However, few studies have applied forest stand structure to explain the variation of species composition within forest communities. In this study, we sampled 19 separate 1-ha forest dynamics plots established among grids of 1 km2 (regional scale) near the 20 ha subtropical mid-mountain moist evergreen broad-leaved forest dynamics plot (local scale, less than 1 km2) in Ailao Mountains as a research platform. Using forest stand structure, environmental factors, and spatial structure variables as the explanatory variables for the species composition variation. We resolved the driving forces of species composition variation at local and regional scales, with an emphasis on the role of forest stand structure in driving the variation of species composition.

Methods: Based on a long-term community survey and airborne LiDAR data, we used redundancy analysis (RDA) and variance partitioning to analyze how environment, spatial structure, and forest stand structure were related to species composition variation in a subtropical evergreen broad-leaved forest at both local and regional scales. To explore the main factors driving the variation of species composition, we analyzed the relative importance of individual explanatory variables using commonality analysis and hierarchical partitioning method.

Results: Inclusion of forest stand structure as an explanatory variable increased the response rate of the variation of species composition at both local and regional scales. However, inclusion of forest stand structure as an explanatory variable resulted in a significant decrease in the rate of spatial structure at the local level. The cumulative contribution of forest stand structure and environment to the variation in species composition was 41.0% at the local level. At the regional scale, forest stand structure and environment contributed a cumulative explanatory rate in species composition was 23.0%.

Conclusions: This study confirms that, for subtropical broad-leaved evergreen forests, forest stand structure characterizing the light environment is an important driver of the variation in species composition, which deepens our understanding of the role of environmental filtering in driving the variation in species composition and remedies the traditional under-consideration of environmental factors. From local to regional scales, the role of purely spatial structure declines sharply to negligible levels. However, the relative importance of environmental filtering is significantly enhanced from the local to the regional scale. Light availability may have a strong effect shaping species composition below the forest canopies. This new relationship between forest stand structure on species composition warrants future studies to explore the causal mechanisms of how forest stand structure drives species composition variation in subtropical broad-leaved evergreen forests.

Key words: forest stand structure, scale effect, LiDAR, light availability, Ailao Mountains