青海高寒区不同人工林配置下草本群落生态位研究

以青海大通高寒区的青海云杉林、华北落叶松林、白桦林、云杉白桦混交林4种人工林群落为研究对象,运用Levins生态位宽度指数及Pianka生态位重叠指数,对不同人工林群落下草本群落的生态位宽度及生态位重叠度进行计算,从生态位角度揭示了不同树种配置下草本群落的生长状况,结果表明:不同人工林下草本群落的广生态幅物种不同,针阔叶混交林更有利于林下草本群落的生长和发育。生态位重叠指数表明:一般情况下,生态位较宽的物种之间存在较大的生态位重叠,但在一些林分中,生态位较窄的物种之间也存在着较大的生态位重叠,这种现象可能是不同草本种群对有限环境资源激烈竞争的体现,针阔叶混交林下草本种群在有限的空间中对资源的利用更加充分。

The Study on Herb Community Niche of Different Plantation Configuration in Alpine Region of Qinghai Province

In this study,the communities of Picea crasslia,Larix principis—rupprechtii,Betula platyphylla and Picea crasslia—Betula platyphylla were selected as objects.In order to show growth of herb community niche of different plantation communities from view of niche,the niche breadth and niche overlapping of herb community were measured by means of levins niche breadth and pianka niche overlapping indexes in different plantation communities.It showed that wide ecological amplitude of species was different in different plantation communities.Broad-leaved mixed forest was the best for vegetation development and regeneration.The niche overlap index suggested that the species with big niche breadth often had big niche overlapping.But in some plantation communities,the species with narrow niche breadth had big niche overlapping.This phenomenon may be due to different herb community competition with each other for limited environmental resources.Herb community of broad-leaved mixed forest can make better use of resources.