灵空山辽东栎林种群生态位特征

摘要

To determine important indicators of resource status, such as species, niche breadth {Bi and Ba), and niche overlap), a survey of datum plots for populations of trees (6 species), shrubs (8 species), and herbs (11 species) within a Quercus liaotungensis forest in the Lingkong Mountains of Shaanxi Province were studied using the niche breadth formulae of Levins and Hurlbert and the niche overlap formula of Levins. Results indicated that in the overstory, niche breadth for Quercus liaotungensis (Bi = 1.159 0 and Ba = 0.796 0) and Pinus tabuli-formis (Bi = 0.990 7 and Ba = 0.536 1) was greatest. In the shrub layer, niche breadth of Spiraea trilobata (Bi; = 1.095 0 and Ba = 0.509 0) was largest In the herb layer, niche breadth of Carex lanceolata (Bi = 1.309 7 and Ba = 0.948 5) was the most prevalent. Degrees of overlap existed among the various layers with the overlap indexes gradually decreasing from the overstory to the understory. Thus, species with a larger niche breadth had stronger resource utilization capabilities, and their niche overlap was greater than other populations.%利用样地调查数据,以物种重要值作为资源状态指标,应用Levins,Hurlbert生态位宽度公式和Levins生态位重叠公式对山西灵空山林区辽东栎Quercus liaotungensis群落6种乔木、8种灌木和11种草本进行了生态位宽度和生态位重叠计算.结果表明:灵空山林区乔木树种以辽东栎(Levins生态位宽度Bi=1.1590,Hurlbert生态位宽度Ba=0.7960),油松Pinus tabulaeformis (Bi=0.990 7,B1a=0.536 1)的生态位宽度值较大；灌木树种以三裂绣线菊Spireae trilobata(Bi=1.095 0,Ba=0.509 0)的生态位宽度值较大；而草本层中,披针薹草Carex lanceolata的生态位宽度值最大(Bi=1.309 7,Ba=0.948 5).乔木、灌木、草本层各种群之间均有不同程度的重叠,重叠指数依乔木、灌木、草本层逐渐减少,总的表现为生态位宽度较大的物种对资源利用能力较强,与其他种群间的生态位重叠一般较大.