生物多样性 ›› 2012, Vol. 20 ›› Issue (2): 159-167.DOI: 10.3724/SP.J.1003.2012.09242

• 研究报告 • 上一篇    下一篇

基于地形因子的天童地区常绿树种和落叶树种共存机制研究

谢玉彬1,2, 马遵平1,2, 杨庆松1,2, 方晓峰1,2, 张志国1,2, 阎恩荣1,2, 王希华1,2,*()   

  1. 1 华东师范大学环境科学系, 上海 200062
    2 浙江天童森林生态系统国家野外科学观测研究站, 浙江宁波 315114
  • 收稿日期:2011-12-29 接受日期:2012-03-13 出版日期:2012-03-20 发布日期:2012-04-09
  • 通讯作者: 王希华
  • 作者简介:* E-mail: xhwang@des.ecnu.edu.cn

Coexistence mechanisms of evergreen and deciduous trees based on topographic factors in Tiantong region, Zhejiang Province, eastern China

Yubin Xie1,2, Zunping Ma1,2, Qingsong Yang1,2, Xiaofeng Fang1,2, Zhiguo Zhang1,2, Enrong Yan1,2, Xihua Wang1,2,*()   

  1. 1 Department of Environmental Science, East China Normal University, Shanghai 200062
    2 Tiantong National Station of Forest Ecosystem, Ningbo, Zhejiang 315114
  • Received:2011-12-29 Accepted:2012-03-13 Online:2012-03-20 Published:2012-04-09
  • Contact: Xihua Wang

摘要:

位于亚热带的浙江天童和古田山常绿阔叶林大样地分布有较高比例的落叶树种, 那么它们与常绿树种的共存机制是什么? 常绿树种和落叶树种生态习性差异较大, 二者对生境的选择应有所不同, 我们推测生境分化可能是两类植物实现共存的主要机制。为检验该假设, 我们以天童20 ha动态样地调查数据为依托, 选择个体数≥20的55个常绿树种和42个落叶树种作为分析对象, 用典范对应分析(CCA)研究了地形因子对二者分布的影响差异, 用torus转换检验来分析常绿树种和落叶树种与各类地形生境的关联。结果如下: (1)CCA分析表明地形因子对常绿树种分布的解释量为19.2%, 对落叶树种分布的解释量为7.0%。(2)torus转换检验结果表明, 与沟谷成正关联的常绿树种和落叶树种的比例分别为16.4%和28.6%, 成负关联的比例分别为40%和7%; 与山脊成正关联的常绿树种和落叶树种的比例分别为41.8%和4.8%, 成负关联的比例分别为10.9%和47.6%; 与受干扰生境成正关联的常绿树种和落叶树种的比例分别为16.4%和42.9%。上述结果说明地形对常绿树种分布的影响大于落叶树种; 两个植物类群对生境的选择多呈现相反格局, 尤其是在沟谷生境和山脊生境, 这进一步表明生境分化是常绿树种和落叶树种共存的重要机制之一, 生态位理论在一定程度上能较好地解释亚热带常绿阔叶林物种多样性的维持。

关键词: 地形, 常绿树种, 落叶树种, 常绿阔叶林, 生态位理论, 生境关联, 共存机制

Abstract

The zonal vegetation of subtropical regions in China is recognized as the evergreen broad-leaved forest (EBLF), a forest that usually contains many deciduous tree species. Preliminary investigation of a 20-ha plot at Tiantong (East China) showed that the proportion of deciduous trees reached 52.6%. How do these evergreen and deciduous trees coexist? Up till now, this question lacks a sufficient answer. Evergreen and deciduous tree species often differ in ecological habits, and this niche differentiation may be manifested in distinct habitat preferences. These habitat differences may be an important point in explaining the mechanisms by which these two groups coexist. To test this hypothesis, on the basis of the aforementioned investigation at Tiantong 20 ha plot, 55 evergreen and 42 deciduous tree species with abundance more than 20 individuals were selected for analysis. Canonical Correspondence Analysis (CCA) was used to explore the influence of topographic factors on spatial distribution, and torus-translation tests were employed to test the significance of the species-topography (elevation, convexity, and slope) association. Results were as follows: (1) CCA analysis showed that the three topographic factors (elevation, convexity and slope) explained 19.2% of the distribution of evergreen trees and 7.0% of that for deciduous trees. (2) 16.4% of the 55 evergreen trees and 28.6% of the 42 deciduous trees showed a significantly positive association with the valley habitat, and the proportion of negative association with the valley habitat was 40% and 7% respectively; 41.8% evergreen trees and 4.8% deciduous trees showed a significantly positive association with the ridge habitat, and the proportion of negative association with the ridge habitat was 10.9% and 47.6% respectively; 16.4% evergreen trees and 42.9% deciduous trees were positively associated with the disturbed habitat. Our results showed that topographic factors significantly influence the distribution of evergreen and deciduous trees in the Tiantong plot, and this influence seems greater for evergreen trees. Evergreen and deciduous trees generally showed opposite trends in habitat preferences, especially in valley and ridge habitats. This indicates that habitat partitioning may be a major mechanism allowing the coexistence of evergreen and deciduous trees, and that the niche theory, to some extent, may be sufficient in explaining species diversity maintenance in subtropical evergreen forests.

Key words: topography, evergreen trees, deciduous trees, evergreen broad-leaved forest, niche theory, habitat association, coexistence mechanisms