桂林岩溶石山常绿落叶阔叶混交林不同叶习性植物功能性状梯度分析

Gradient Analysis of Functional Traits of Different Leaf Habit Plants in Evergreen Deciduous Broad-leaved Mixed Forest in Karst Hills of Guilin,Southwest China

以桂林岩溶石山常绿落叶阔叶混交林不同叶习性树种为研究对象,在55个样方88种木本植物的6种功能性状数据的基础上,采用性状梯度分析法研究不同叶习性共存物种的性状差异和生态策略选择。结果表明,常绿树种的叶绿素含量、叶厚度、叶干物质含量和木材密度高于落叶树种,而落叶树种的叶面积和比叶面积高于常绿树种。落叶树种的生态位宽度大于常绿树种的生态位宽度。说明常绿树种采取维持生长、延长叶寿命为主的保守策略,而落叶树种采取以提高资源利用效率为主的积极策略。常绿和落叶树种6个功能性状的α值变化范围都比β值的变化范围大,说明共存物种之间的相互作用比环境因素对物种性状的影响更大,且群落内的作用强于群落间的作用。常绿和落叶树种β值的相关性很高,而α值的相关性很低。说明多个植物功能性状在所处群落中表现出更高的整体差异,功能性状在群落间的相关性大于群落内的相关性。性状间的不相关或弱相关表明,不同性状在2种叶习性树种的生长发育中表现出独立的维度。研究不同叶习性物种功能性状在环境梯度上的差异,对了解常绿和落叶物种的共存机制及群落构建和生物多样性维持机制具有重要意义。

In this paper,we studied different leaf habit tree species in the evergreen deciduous broad-leaved mixed forest of karst hills in Guilin,Southwest China.Based on the data of 6 functional traits of 88 woody plants in 55 plots,we used the trait-gradient analysis to study the coexistence of different leaf habit species trait differences and ecological strategy selection.The results showed that:there were significant differences in the functional traits between evergreen tree species and deciduous tree species.Leaf chlorophyll content(Chl),leaf thickness(LT),leaf dry matter content(LDMC)and wood density(WD)of evergreen tree species were higher than deciduous tree species,while lamina area(LA)and specific leaf area(SLA)of deciduous tree species were higher than evergreen tree species.The niche width of deciduous tree species was larger than evergreen tree species.It showed that evergreen tree species adopted a conservative strategy to maintain growth and extend leaf life,while deciduous tree species adopted a positive strategy to improve resource utilization efficiency.The range of the alpha value of the six functional traits of evergreen and deciduous tree species was larger than the beta value,indicating that the interaction between coexisting species had a greater impact on the species traits than environmental factors,and the role of within-site stronger than the role of among-site.There were high correlations between the beta component of evergreen and deciduous tree species,while low correlation was found between evergreen tree species and deciduous tree species in the alpha component.This suggested that multiple plant functional traits showed higher differences in the communities where they were located.The correlation between functional traits among communities was greater than that within communities.No-correlation or weak correlation between traits indicated that different traits showed independent dimensions in the growth and development of two leaf habit tree species.Studying the differences in the functional traits of different leaf habit species on environmental gradients is of great significance for understanding the coexistence mechanism of evergreen and deciduous species,community construction and biodiversity maintenance mechanisms.