浙江文成珍稀植物多脉铁木群落结构及物种多样性

以浙江省文成县石垟林场的多脉铁木Ostrya multinervis群落为对象，采用标准样地法研究了该群落植物种类、数量特征、物种多样性和群落的垂直和径阶结构。结果表明:该群落资源丰富，共有维管束植物60种（含变种），隶属于40科52属，其中蕨类植物6科7属8种，裸子植物1科1属1种，被子植物33科44属51种。多脉铁木群落垂直结构明显，可分为乔木层、灌木层和草本层，其中乔木层优势树种为多脉铁木，灌木层优势种为披针叶茴香Illicium lanceolatum，草本层优势种为里白Diplopterygium glaucum。群落中的生活型以高位芽植物数量最多，占41.7%。群落中灌木层植物最为丰富，Shannon-Wiener多样性指数、Simpson优势度指数和Pielou均匀度指数均大于草本层和乔木层。整个林分乔木层树种的树高分布相对均匀，径阶分布为逆J字型，多脉铁木单一树种的垂直和径阶结构均为近正态分布，多脉铁木群落具有较高的物种多样性和群落稳定性。幼苗个体缺乏是导致其濒危的重要原因之一。建议在目前封山育林保护基础上，加强多脉铁木高效繁育技术研究，并适当进行人工抚育，以保证其种群的正常更新。

Structural characteristics and species diversity for survival of the rare plant Ostrya multinervis

Ostrya multinervis is an endangered species to China. To understand the O. multinervis plant community's structural characteristics and species diversity so as to protect this rare and endangered plant. A survey of the community structure and species diversity of O. multinervis was conducted through quadrat sampling at Shiyang Forest Farm, Wencheng County, Zhejiang Province. Using permanent plots and the technique of examining every individual, all trees in quadrats established in the community to quantify the community structural characteristics were identified and measured. Analysis included the Shannon-Wiener, Simpson, and Pielou indexes. Results showed 40 families, 52 genera, and 60 species of vascular plants with eight species of pteridophyte belonging to seven genera in six families, one species of gymnosperms belonging to one genus in one family, and 51 species of angiosperms belonging to 44 genera in 33 families. The vertical structure was composed of three layers:tree layer, shrub layer, and herb layer, in which O. multinervis was the dominant species in the tree layer, Illicium lanceolatum was the dominant species in the shrub layer, and Diplopterygium glaucum was the dominant species in the herb layer. Overall, phanerophytes accounted for the greatest number (41.7%). Species richness for the shrub layer was the largest of the three communities with the Shannon-Wiener, Simpson, and Pielou indexes larger than herb and tree layers(P < 0.05). Tree height distribution in the tree layer for whole trees was relatively uniform, the diameter order was an inverse J type species distribution, and tree height and diameter structure showed near normal distributions for O. multinervis. In summary, O. multinervis communities had a high species diversity and community stability, but were endangered by a lack of young individuals which could be overcome with closure of hillsides to facilitate afforestation, strengthening of research on highly efficient breeding technologies for O. multinervis, and implementation of artificial rearing measures to ensure a normal development of the population.