湖北长阳光叶珙桐群落优势乔木种群生态宽度与重叠

Niche Breadths and Overlaps of Dominant Arbor Populations in Davidia involucrata var.vilmoriniana Community in Changyang County of Hubei Province

采用样方法进行不同资源位群落调查,利用生态位宽度和生态位重叠公式研究了湖北省长阳光叶珙桐(Davidia involucratavar.vilmoriniana)群落14个优势种群的生态位.结果表明:光叶珙桐、华西枫杨(Pterocarya in-signis)、大叶青冈(Cyclobalanopsis jenseniana)、水青树(Tetracentron sinense)的生态位宽度较大,其Bi和Ba值分别为1.8478、0.8031,1.5881、0.6336,1.3969、0.4171和1.3482、0.452 4;白辛树(Pterostyrax hispidus)的生态位宽度较小,其Bi和Ba分别为0.5466和0.0941.光叶珙桐群落中生态位重叠值大于0.1的有56对,占总对数的60.2%,生态位重叠程度较大,表明光叶珙桐群落中因利用相同的资源位而产生的种间竞争较激烈,群落结构可能具有一定的不稳定性.

A field plot sampling method was employed to investigate community niche of Davidia involucrate var.vilmoriniana community in Changyang county,Hubei Province.Parameters of niche breadth and niche overlap were calculated to show community characteristics of 14 dominant species.The results showed that niche breadths of D.involucrate var.vilmoriniana,Pterocarya insignis,Cyclobalanopsis jenseniana and Tetracentron sinense were larger than other species,with Levins（Bi） and Hurlbert′s（Ba） values being 1.8478 and 0.8031,1.5881 and 0.6336,1.3969 and 0.4171,1.3482 and 0.4524 respectively.While,the niche breadths of Pterostyrax hispidus had smaller niche breadth,with Bi and Ba values being 0.5466 and 0.0941.The niche overlap degree was large between species in D.involucrate var.vilmoriniana community,with values larger than 0.1 accounting for 60.2%,suggesting that the inter-specific competition is intensive and the community structure is probably instable.