珍稀濒危植物堇叶紫金牛生存群落结构特征及物种多样性

以浙江省建德市绿荷塘森林公园堇叶紫金牛Ardisia violacea生存群落为对象,应用标准样地法和每木调查法调查了群落种类和结构特征,并用群落学方法计算了群落内乔木层各树种的重要值,采用Shannon-Weiner指数、Simpson指数、Pielou均匀度指数分别研究了群落内3个样地中乔木层、灌木层、草本层的物种多样性,并根据胸径级频率分布的形状,将主要乔木层树种的种群结构分为3种类型.结果表明:该群落资源丰富,共有维管束植物116种(含变种),隶属于47科79属.从生活型上区分来看,堇叶紫金牛生存群落中共出现木本植物83种,其中针叶树2种,常绿阔叶树48种,落叶阔叶树33种,群落以小高位芽植物和矮高位芽植物的种类较多.根据分布生境、群落结构和种类组成,可以将堇叶紫金牛生存群落分为3个类型:甜槠Castanopsis eyrei-栲树Castanopsis fargesii林,杉阔混交林和杉木Cunninghamia lanceolata人工林.在垂直结构方面,大体包括乔木层、灌木层、草本层,此外还有一些层间植物,而且种类较为丰富,并且3种类型群落的高度结构大致相同.在3个样地中灌木层中的物种丰富度指数均为最大.杉阔混交林中草本层的Shannon-Weiner指数最大,而甜槠-栲树林和杉木人工林中灌木层Shannon-Weiner指数最大.Simpson指数在甜槠-栲树林和杉木人工林中乔木层最大,而在杉阔混交林中灌木层最大.主要乔木层种群结构为单峰型的枫香Liquidambar formosana,拟赤杨Alniphyllum fortunei,马尾松Pinus massoniana为阳性乔木树种,无正常更新能力,在演替后期比较稳定的群落中,将最终衰退消失；间歇型的青冈Cyclobalanopsis glauca,木荷Schima superba,乌药Lindera aggregata等为不连续生长型,更新具有波动性和机会性,介于顶极群落先锋种和优势种之间；逆J-字型的杉木、甜槠、栲树、山矾Symplocos caudata等常绿阔叶乔木树种,为顶极群落的优势种.

Structural characteristics and species diversity of the endangered plant A rdisia violacea

To understand the A rdisia violacea plant community＇s structural characteristics so as to protect this rare and endangered plant, a survey of community structure and species diversity was conducted through quadrat sampling in Ltihetang Forest Park, Jiande City, Zhejiang Province. Using permanent plots and examining every individual within, all trees were identified and measured. To describe community population characteristics, importance values of tree populations were calculated, Raunkiaer＇s life-form spectrum was used, and species diversity of tree and shrub layers were analyzed using Shannon-Weiner. Simpson. and Pielouevenness indexes. The population age structure of the different tree layer species were categorized into three regeneration types： unimodal, sporadic, and inverse-J. Results showed 47 families, 79 genera, and 116 species of vascular plants. Raunkiaer＇s life-form spectrum revealed that micro-phanerophytes and nano-phanerophytes characterized the forest. Structural features of the community for the woody layer included two evergreen conifers species, 48 evergreen broadleaved trees species, and 33 deciduous broadleaved trees species. Using habitat, community structure, and species Composition, communities with Ardisia violacea were found in three forest community types： Castanopsis eyrei-Castanopsis fargesii, mixed Cunninghamia lanceolata- broadleaf, and Cunninghamia lanceolata. Vertical structure was composed of four layers： tree, shrub, herb and interlayer with the height structure being similar （P〉0.05）. Species richness in the three communities wasgreatest for the shrub layer （45, 30, 29, P〈0.05）. For the Shannon-Weiner index, the mixed Cunning- hamia lanceolata-broadleaved community herb layer was biggest （2.42, P〈0.01） ; whereas the Castanopsis eyrei-Castanopsisfargesii and Cunninghamia lanceolata community shrub layers were largest （2.61, 2.37, P〈 0.01 ）. For the Simpson index, the Castanopsis eyrei Castanopsis fargesii and the Cunninghamia lanceolata community tree layers were hugest （5.130, 6.957, P〈0.01） ; whereas the mixed Cunninghamia lanceolata- broadleaved community shrub layer was largest （6.097, P〈0.01 ）. Unimodal type species included Liquidambar formosana, Alniphyllum fortunei, and Pinus massoniana; sporadic type species included Cyclobalanopsis glauca, Schima superba, and Lindera aggregata; and inverse-J type species were Cunninghamia lanceolata, Castanopsis eyrei, Castanopsis fargesii, and Symplocos caudate. In allusion to the biological characteristics of Ardisia violacea, means of in situ conservation was supposed to be taken as the most important management countermeasure for the forest in the future. In addition, it should be done that intermediate selective cutting of the subordinate species in the tree and shrub layer so as to create a good condition for Ardisia violacea popula- tions regeneration and development. Ch, 2 fig. 7 tab. 29 ref. ]