外来树种的引种对百山祖自然保护区原生植被植物物种多样性的影响

Effects of Introduced Trees on Biodiversity of Local Vegetation of Baishanzu Natural Protection Area

为了研究引栽日本冷杉、北美香柏、日本花柏、日本扁柏等外来树种对百山祖自然保护区原生植被植物物种多样性的影响,采用相邻格子样方法对以外来树种为优势种的百山祖主峰植物群落和原生的锅帽尖植物群落进行了野外调查,并对其植物群落的植物物种多样性作了分析比较。结果表明:百山祖主峰自引栽外来树种后,形成了以外来树种为优势种具乔木层、灌木层和草本层的植物群落结构,其各层次物种多样性的次序是灌木层>乔木层>草本层;与之相比的锅帽尖原生植物群落没有形成乔木层,其草本层的盖度较高,各层次的植物物种多样性的次序是灌木层>草本层。两者植物的物种多样性比较是百山祖主峰>锅帽尖;草本植物的物种丰富度比较是锅帽尖>百山祖主峰。说明外来树种的引栽提高了引栽点植物群落的木本植物物种多样性,降低了草本植物的物种多样性。值得关注的是随着引种的外来树种树高的增长,林分的郁闭,对本土植物生长所造成的影响性。

In order to study the effects of introduced trees like Abies firma, Thuja occidentalis, Chamaecyparis pisifera and Chamaecyparis obtusa on the biodiversity of vegetation in Baishanzu Natural Protection Area, we used an adjacent quadrates to study the vegetation of Mount Baishanzu which had dominant tree species of introduced trees and that of in Guomaojian Mount which had dominant tree species of local plants, and then compared the plant communities of the two places. It showed that after the introduction of foreign trees in Mount Baishanzu for years, there had formed vegetation of dominant trees that were foreign species, which had formed three layers of arbor, shrub and herb. The extent of biodiversity of three layers was ranked as shrub 〉 arbor 〉 herb; in Mount Guomaojian, there was no formation of the layer of arbor, and there was higher coverage rate of herb, biodiversity in herb layer was higher in Mount Guomaojian than that of Mount Baishanzu. This suggested that the introduction of foreign trees increased biodiversity in arbor layer but decreased in herb layer. It was worthwhile noting that the conse- quences of introduced trees on local plants after closure of increasing stand.