浙江天童常绿阔叶林演替阶段共有种的树木构型  

Tree architecture of overlapping species among successional stages in evergreen broad-leaved forests in Tiantong region, Zhejiang Province, China

作　　者：杨晓东[1,2] 阎恩荣 张志浩[1,2] 孙宝伟 黄海侠[1,2]  Ali ARSHAD 马文济[1,2] 史青茹 

机构地区：[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

出　　处：《植物生态学报》2013年第7期611-619,共9页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(31270475和31070-383)

摘　　要：树木构型是木本植物为响应光照变化在其空间建造结构上的配置模式和形态体现。研究演替不同阶段共有种构型的变化可以剔除植物谱系的影响,反映植物构型特征与光资源供给性的关系。该研究在浙江宁波天童、南山和北仑3个次生演替序列上选择了5个演替共有种,分4个群落高度层级,对照分析了树高、冠幅深度和面积、枝条伸展方向、基径、叶片盖度和聚集度构型性状随演替的变化,并分析了与冠幅曝光指数的线性关系。结果表明:1)随着演替进行,冠幅厚度和面积、叶片盖度、叶片聚集度和基径逐步增加,但在个别相邻演替阶段增加不显著;2)随着演替进行,植物的垂直枝比例降低,水平枝比例增加;3)演替过程中植物冠幅曝光指数在各层级内都呈现出减小趋势;4)构型性状和植物冠幅曝光指数间存在显著的线性回归关系(p<0.001)。总之,随着常绿阔叶林演替进行,演替共有种构型的变化反映了物种功能类群由阳性先锋植物向耐阴植物的转化,其中,植物对光资源的适应是导致构型变化的主要原因。Aims Tree architecture refers to the overall shape and size of the woody plants, as well as the spatial arrangement of its components in response to changing light. Variation in tree architecture of overlapping species among successional stages can be used to indicate relationships between tree architecture and light availability, because confounding effects resulted from plant phylogenetics are excluded. Our objective was to examine how tree architecture varies among overlapping species in different successional stages. Methods The study sites are located in Tiantong National Forest Park （29°52′ N, 121°39′ E）, Nanshan Mountain （29°52′ N, 121°41′ E） and Beilun Forest Park （29°50′ N, 121°52′ E） in Zhejiang Province, China. We measured tree height, crown depth and area, stem basal diameter, leaf coverage and convergence, stretch direction of branch and crown exposure index for five overlapping species in four vertical layers among successional communities in three sites. Linear regression analysis was conducted to examine the quantitative relationship between tree archi- tecture and crown exposure index. Important findings With the forest succession, crown depth and area, leaf coverage and stem basal diameter increased gradually, but did not show significant differences between adjacent successional stages in some cases. The proportion of dispersed leaves increased, but the proportion of clumped leaves decreased. Among four verti- cal layers, crown exposure index decreased through forest succession. There were significant linear relationships between crown exposure index and each of eight tree architectural traits （p 〈 0.001）. We conclude that variability in tree architecture among overlapping species through forest succession indicates a shifting pattem of plant func- tional groups from pioneer species to shade-tolerant species in evergreen broad-leaved forests. Light acclimatization is one of main factors driving variation in tree architecture.

关 键 词：冠幅曝光指数 常绿阔叶林 共有种 次生演替 树木构型 

分 类 号：S718.54[农业科学—林学]