绵阳官司河流域天然次生林种群的生态位特征

Niche Characteristics of Plant Populations in Natural Secondary Forests in the Guansi River Cacthment in Mianyang City,Sichuan Province

基于绵阳官司河流域天然次生林群落57块100 m^2的样地调查数据,以微地形地貌作为一维资源位状态,以物种的重要值为生态位计测的资源状态指标,对该流域主要乔木、灌木种群的生态位宽度、生态位相似性和生态位重叠进行了计算与分析。结果表明,主要优势种群的生态位宽度较大,乔木层主要优势种群马尾松、柏木、栓皮栎等Levins生态位宽度值分别为0.841、0.816、0.907,灌木层主要优势种群铁仔、三颗针、黄荆、火棘等Levins生态位宽度值分别为0.985、0.965、0.952、0.882。群落中各种群之间的生态位关系较复杂,生态位宽度较大的物种对资源利用能力较强,彼此之间的生态位相似性和生态位重叠值较大,对资源具有一定的共享性,存在生态位分离现象。种群之间的生态位相似比例和生态位重叠值分布状况,反映了该流域植被恢复过程中森林群落的生态位特征。

In this paper, based on the data collected from 57 plots （each plot has 100 m^2 in the size）, calculation and analysis are made of the niche breadths, niche similarity and overlapping of dominant trees and shrub populations in natural secondary forests of the Guansi River catchment with micro-topography and micro-physiognomy as the resource state and value of importance as the resource state descriptor of niche. The results have shown that the Levins＇niche breadths of Pinus massoniana, Cupressusfunebris, Quercus variabilis in arbor layer are 0. 841,0. 816 and 0.907, respectively, and those of Myrsine Africana, Berberis julianae, Vitex negurdo, Pyracantha fortuneana in shrub layer are 0. 985, 0. 965, 0. 952 and 0.882, respectively. The relation among the species is very complex. The index of both niche similarity and niche overlapping between the species with bigger niche breadth is generally higher, sharing the broader resource, but there is a niche separation in the resource state. Among the species in the communities, the proportion of niche similarity and the distribution of the niche overlapping index constitute the niche characteristics of natural secondary forests in the process of vegetation restoration in this area.