不同植被类型植物物种多样性

Plant's diversity of different vegetation types

为了评价大面积人工种植杜仲对当地植物多样性的影响,以河南省汝阳县不同植被类型为研究对象,通过群落学调查,运用重要值、Shannon-Wiener物种多样性指数(H)、Simpson物种多样性指数(D)和均匀度指数(JH')等指标,统计分析杜仲人工林、温带落叶阔叶林(以下简称次生林)和撂荒地3种不同植被类型的植物物种多样性,探讨杜仲种植对植物多样性的影响。调查发现,杜仲林样地中出现植物82种,隶属39科63属,草本层为最发达的一层;次生林样地中出现植物70种,隶属32科62属,乔木层为最发达层;撂荒地样地中出现植物84种,隶属35科69属,无乔木层。杜仲林物种丰富度和多度均不亚于次生林和撂荒地,且杜仲林草本层物种丰富度和植株总数均高于次生林。统计分析显示,杜仲林乔木层、灌木层和草本层多样性指数H和D值、均匀度指数JH'值与其它两种植被类型相比无显著性差异(P>0.05)。因此,种植杜仲过程中采用合理密度,适当管理,不仅能提供叶、花、果等资源,而且能够丰富草本植物的种类和数量,增加植物物种多样性。

Human-driven ecosystem simplification has highlighted questions about how the number of species in an ecosystem influences its functioning. Biodiversity is now known to affect ecosystem productivity and stability of the ecosystem. In this study, different vegetation types in Ruyang County, Henan Province, China, were examined to evaluate the impact of large-scale planting of Eucommia ulmoides on local species diversity. The species diversity was analyzed using Shannon-Wiener diversity （H）, Simpson diversity （D）, and evenness （JH＇） indices in three different vegetation types： Eucommia ulmoides plantation, temperate fallen broad-leaved forest （referred to as secondary forest）, and abandoned land （old field）. The results indicated that there were 82 species belonging to 39 families and 63 genera in the Eucommia ulmoides forest, in which the herbaceous layer was the most developed. The secondary forest contained 70 species belonging to 32 families and 62 genera, and the tree layer was more developed than more developed than the herbaceous and shrub layers. The old field included 84 species of 35 families and 69 genera but lacked a tree layer. The richness and abundance of species in the Eucommia ulmoides forest were similar to those in the secondary forest and old field, whereas the richness and abundance of species in the herbaceous layer of the Eucommia ulmoides forest were higher than those in the secondary forest. Our results showed that the H, D, and JH indices of the three layers of the Eucommia ulmoides forest were not significantly different from those of the secondary forest and old field （P 〉 0.05 ）. Collectively, these results illustrate that, with a reasonable planting density and proper management, Eucommia ulmoides forests can not only provide us with leaves and fruit but can also enrich the amount and diversity of herbaceous plants, thereby increasing biological diversity.