镇雄县珙桐群落特征及种群更新研究

摘要

This paper conducted an investigation of Davidia involucrata community on 11 plots,a total of 1.6 hm2 in Zhenxiong County,of which 8 samples using 20m × 20m sampling method,3 samples measured by the feild method.The investigation focused on community species composition,floristic composition,structure characteristics and regeneration of Davidia involucrata.The results showed that:Davidia involucrata community was rich in species,a total of 6 families of ferns belonging to 7 genera and 8 species,54 families,102 genera and 123 species of angiosperms with feature of ancient,unique and strong;the Angiosperm Flora community composed in temperate type,accounting for about 60.95％;The structure of the community of Davidia involucrata was dominated by small leaf and high bud plants,indicating that the habitat was warm and humid;the diameter structure of Davidia involucrata showed obvious inverted pyramid shape,which indicated that the population was poorly renewed and in the recession stage.%采用典型抽样法在镇雄县珙桐分布区设置11个样地,其中8个样地采用20 m×20 m样方法,3个样地采用实测法,样地总面积计1.6 hm2,对珙桐群落进行野外调查,重点分析该地区珙桐群落的物种构成、区系特征及珙桐更新状况.结果表明,该地区珙桐群落植物种类十分丰富,共有蕨类植物6科7属8种,被子植物54科102属123种,且古老性、特有性强;群落被子植物的区系构成中以温带分布型为主,约占分布区类型的60.95％;珙桐群落中生活型以小型叶、高位芽植物为主,表明其生境较温暖湿润;珙桐群落径级结构呈现明显的倒金字塔形,表明种群更新较差,处于衰退阶段.