古田山木本植物功能性状的系统发育信号及其对群落结构的影响

The phylogenetic signal of functional traits and their effects on community structure in an evergreen broad-leaved forest

植物功能性状(plant functional trait)的进化历史及其与群落结构的关系是近年来生态学研究的热点问题之一。为探究植物功能性状受系统进化历史的影响程度,以及功能性状是否通过影响物种多度分布进而影响群落结构等问题,本研究以古田山24 ha永久性监测样地中的156种木本植物为对象,收集了叶片氮含量、叶片磷含量、叶面积、木质密度、比叶面积和种子重量6种功能性状的数据,用K值法检验了各个功能性状的系统发育信号(phylogenetic signal),并运用系统发育独立比较(phylogenetic independent contrasts,PIC)的方法分析了各个性状与多度的关系。结果显示,所有6种功能性状都表现出较强的系统发育信号,表明本区域木本植物系统发育历史显著地影响这些功能性状;另一方面,叶氮含量、叶磷含量、叶面积、木质密度和比叶面积与物种多度显著相关,而种子重量与物种多度没有显著的相关性,表明群落内不同物种的资源获取方式可显著地影响群落的结构。

The phylogenetic conservatism of plant functional traits and its association with community structure are important topics in ecological research. Plant functional traits are simultaneously affected by their evolutionary background, local habitat conditions and large-scale climate. In this study we asked whether functional traits have a significant phylogenetic signal and significantly affect species abundance in a community. For this objective, we used data from a 24 ha Gutianshan forest plot, which included species abundance and six functional traits of 156 woody species： leaf nitrogen content, leaf phosphorus content, leaf area, wood density, specific leaf area and seed mass. We found that all functional traits showed significant phylogenetic signal, suggesting that all functional traits are significantly affected by their evolutionary history. We also found that species abundance was correlated with leaf nitrogen content, leaf phosphorus content, leaf area, woody density and specific leaf area except seed mass, suggesting that resource acquisition significantly affects species abundance distribution in a community, and that these functional traits impact community structure in different ways.