3个优势科树种叶功能性状及其关联特性

以小尺度范围内的木兰科、壳斗科和樟科各8种木本植物为研究对象,从分类单元科与种、功能群角度分析了叶功能性状特征及其关联性。结果表明:壳斗科树种的叶柄直径(1.08±0.22)和比叶面积(SLA)(90.87±25.35)显著低于樟科和木兰科,而樟科和木兰科之间差别不明显。叶含氮量在科间没有显著差异。从功能群比较,常绿树种比叶面积(90.10±23.15)显著低于落叶树种(134.65±27.77),但单位叶面积含氮量常绿树种(1.95±0.50)显著高于落叶树种(1.31±0.26)。在不同功能群中,叶面积与叶柄质量有很好的拟合直线关系。叶氮含量仅在常绿树种与其他叶性状有较好的拟合直线关系。叶性状相关性系数大于0.900的有:群落水平物种间叶面积与叶柄质量之间;功能群水平常绿树种叶面积与叶柄直径和叶柄质量间,落叶树种叶柄质量与叶面积和叶柄长间。其他叶性状间也表现不同程度的相关性,表明叶性状之间存在生长发育非同步也即异速生长现象。

Leaf functional traits and correlations in the three dominant families (Magnoliaceae, Fagaceae and Lauraceae)

Leaf functional traits and correlations between them were analyzed according to the class units: family and species,and functional group for 8 tree species in Magnoliaceae,Fagaceae and Lauraceae individually.The results showed that petiole diameters(1.08±0.22) and SLA(90.87±25.35) of species in Fagaceae were significant lower than that in Lauraceae and Magnoliaceae,and there was no significant difference between Lauraceae and Magnoliaceae.Nitrogen content in leaves had no significant differences among Magnoliaceae,Fagaceae and Lauraceae.SLA of evergreen trees(90.10±23.15) was lower significantly than that of deciduous trees(134.65±27.77) according to the class-functional groups,but leaf nitrogen content(g/m2) was higher significantly in evergreen trees(1.95±0.50) than that in deciduous trees(1.31±0.26).Leaf area was linearly correlated with petiole mass for the trees in functional groups.However,leaf nitrogen content was linearly correlated with the other leaf traits only in evergreen trees.Correlation coefficients were greater than 0.900 between leaf area and petiole mass for community level,leaf area and petiole mass or petiole diameters for functional groups,petiole mass and leaf area or petiole length for deciduous trees.Certain correlations also existed among other leaf traits,which showed the growth and development of leaf were non-synchronization,namely allometric growth.