对淮北相山混交林5个优势种叶片的生态解剖学观察表明,其叶片结构具有一定的旱生特征:表皮具发达的表皮毛或角质层,全栅等面叶或具发达的栅栏组织,维管组织发达。牡荆(Vitex negundo var. cannabifolia)和酸枣(Ziziphus jujuba var. spinosa)作为两个广布优势树种,叶片结构表现出很大的可塑性:1)同一群落环境(混交林)中,叶片结构随着季节的变化表现出发育可塑性(5月初的叶片比9月中旬更具有阳生叶的特点);2)不同恢复演替阶段的群落中,叶片结构随着群落环境的变化表现出环境可塑性,其变化趋势为:灌草丛(旱生/阳生)-灌丛(旱生/阳生)-落叶疏林(中生/阳生)-人工侧柏(Platycladus orientalis)林(中生/阴生)。这种可塑性既是植物适应其异质生境的一种重要机制,同时又是不同群落环境的反映。非参数相关分析表明,牡荆和酸枣的叶片结构受多个生态因子综合影响,其中水分和风速是影响叶片结构的主导因子。叶片的上表皮角质层厚度、气孔器密度、栅栏组织厚度、叶片厚度、木质部厚度、韧皮部厚度、维管束厚度等性状均与土壤含水量和空气相对湿度呈显著负相关,与风速呈显著正相关。

The results of eco_anatomical observations on the leaf blades of 5 dominant species in a mixed forest of Xiangshan Mountain, Huaibei, China, indicated that these species share some xeromorphic characteristics such as a developed epidermal cuticle or hairs, total_palisade or flourishing palisade tissue, and developed vascular tissue in middle vein. Ziziphus jujuba var. spinosa and Vitex negundo var. cannabifolia, the two dominant species widely distributed throughout Xiangshan Mountain, show great plasticity in their lamina structure in two aspects: 1) Within the same community, the lamina structure shows temporal developmental plasticity with leaves collected at the beginning of May being more characteristic of sun plants as compared to those in mid September; 2) In different successional community, lamina structure are indicative of environmental plasticity. The shrub_herb communities tend to have xeromorphic/sun leaves, shrub communities have xeromorphic/sun leaves, the sparse mixed forest has mesophytic/sun leaves, and the Platycladus orientalis forest has mesophytic/shade leaves. These differences in leaf anatomy reflect both the ability for plants to adapt heterogeneous habitats as well as differences in the environment of the different communities. The results of non_parameter correlation analysis showed that the lamina structure was influenced by many environment factors, with soil water content, relative humidity and wind velocity being the principle factors. Lamina anatomical characteristics, such as cuticle thickness of the upper epidermis, stomatal density, thickness of the palisade tissue, leaf thickness, xylem thickness and bundle thickness of the middle vein, all were negatively correlated to soil water content and relative humidity and positively correlated to wind velocity.