星斗山常绿落叶阔叶混交林木本植物叶功能性状及其多样性特征分析

为探究亚热带常绿落叶阔叶混交林中木本植物叶功能性状的变异特征,以及群落功能多样性在海拔梯度下的响应规律。该研究以鄂西南地区的星斗山国家级自然保护区海拔1 200～1 700 m的常绿落叶阔叶混交林为研究对象,对群落内木本植物的叶面积(LA)、比叶面积(SLA)、叶干物质含量(LDMC)、叶厚度(LT)、叶氮含量(LNC)、叶磷含量(LPC)6种叶功能性状的变异特征进行了分析,并分析了群落水平下木本植物叶功能性状和功能多样性对海拔变化的响应。结果表明:(1)星斗山保护区内木本植物叶面积、比叶面积、叶干物质含量、叶厚度、叶氮含量和叶磷含量平均值分别为151.49 cm~2、247.98 cm~2/g、34.08%、0.21 mm、16.59 mg/g和0.04 mg/g,其变异幅度依次为206.96%、57.00%、28.15%、52.38%、24.83%和76.92%。(2)在植物科、叶习性、生活型和树高4个因素中,科类群对6种叶功能性状的影响最大,其次为叶习性。(3)海拔对叶面积、叶干物质含量、叶磷含量影响极显著(P0.001),但对比叶面积、叶厚度和叶氮含量无显著影响(P0.05)。(4)不同海拔梯度上群落生物承载量、功能丰富度、功能分离度和功能离散度均达到显著差异(P0.05),仅功能均匀度在海拔梯度上差异不显著。

Analysis of Leaf Functional Traits and Functional Diversity of Woody Plants in Evergreen and Deciduous Broad leaved Mixed Forest of Xingdoushan

This paper characterized the variation in leaf functional traits of woody plants in a subtropical evergreen and deciduous broad leaved mixed forest, and the response of community functional diversity to altitude gradient, which was located in the altitudes from 1 200 and 1 700 m in Xingdoushan National Nature Reserve in southwest Hubei. The leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf thickness (LT) and leaf nitrogen content (LNC) of woody plants in the forest community, and the variation characteristics of six leaf functional traits in leaf phosphorus content (LPC) were analyzed. The response of leaf functional traits and functional diversity of woody plants to altitude changes was also analyzed. The results showed that: (1) the average leaf area, specific leaf area, leaf dry matter content, leaf thickness, leaf nitrogen content and leaf phosphorus content of woody plants in the Xingdoushan Nature Reserve were 151.49 cm², 247.98 cm²/g and 34.08%, 0.21 mm, 16.59 mg/g and 0.04 mg/g, respectively, and their variation ranges were 206.96%, 57.00%, 28.15%, 52.38%, 24.83% and 76.92%. (2) Among the four factors of the family, leaf habit, life form and tree height category, the family had the greatest influence on the six leaf functional traits, followed by leaf habit. (3) The altitude had a significant effect on leaf area, leaf dry matter content and leaf phosphorus content (P<0.001). However, its effect on leaf area, leaf thickness and leaf nitrogen content were not significant (P>0.05). (4) The biological activity, functional richness, functional divergence and functional dispersion of the community were significantly different on different altitude gradients (P<0.05), only the functional evenness was not significantly different in the altitude gradient (P>0.05).