采用实地踏查及样方法,对浙江九龙山国家级自然保护区6 块样地内伯乐树(Bretschneidera sinensis Hemsl.)的分布和群落特征及种群结构进行了初步研究。调查结果表明:伯乐树分布于该保护区内海拔438 ~1 134 m 的低山区域,大多呈零星分布,数量少(仅23 株)且分布范围狭窄,分布总面积约15 hm² 。根据群落外貌和乔木层优势种,可将6 个样地分为3 种群落类型:落叶阔叶林,主要包括香椿-枫香树群落(Toona sinensis-Liquidambar formosana community)和赤杨叶群落(Alniphyllum fortunei community);针阔叶混交林,主要包括杉木-甜槠群落(Cunninghamialanceolata-Castanopsis eyrei community)、杉木-木荷群落(Cunninghamia lanceolata-Schima superba community)和马尾松-木荷群落(Pinus massoniana-Schima superba community);杉木- 毛竹林,即杉木- 毛竹群落(Cunninghamia lanceolata-Phyllostachys heterocycla ‘Pubescens’community)。在针阔叶混交林中伯乐树生长最好、分布数量最多,在 落叶阔叶林中生长较差。根据胸径和株高可将种群结构分为6 个径级,其中Ⅰ级幼苗和Ⅱ级幼树数量为0;Ⅲ级和Ⅳ级成年株数量分别占总株数的17. 39%和4. 35%;而Ⅴ级成熟株数量最多,占总株数的60. 87%;Ⅵ级衰老株数量也占总株数的17. 39%。研究结果表明:该伯乐树种群为衰退型种群,幼苗和幼树数量明显不足,因而,应加强人工繁育研究、有效扩大种群规模。

Distribution, community characteristics and population structure of Bretschneidera sinensis Hemsl. in six sampling plots in Zhejiang Jiulongshan National Natural Reserve were preliminarily studied by field survey and quadrat method. The investigation results show that B. sinensis distributs in hilly region of the reserve with altitude 438-1 134 m, and most distribute separately with a few amount (only 23 individuals) and narrow distribution range, and its distribution area is only 15 hm². According to community physiognomy and dominant species in arbor layer, six sampling plots can be divided into three community types: deciduous broad-leaved forest including Toona sinensis-Liquidambar formosana community and Alniphyllum fortunei community; coniferous and broad-leaved mixed forest including Cunninghamia lanceolata-Castanopsis eyrei community, Cunninghamia lanceolata-Schima superba community and Pinus massoniana-Schima superba community; and fir-bamboo forest, that is Cunninghamia lanceolata-Phyllostachys heterocycla ‘Pubescens’community. B. sinensis grows best with the most amount in coniferous and broad-leaved mixed forest, but worse in deciduous broad-leaved forest. Population structure of B. sinensis is divided into six diameter classes according to tree height and diameter at breast height. In which, the number of seedling in Ⅰclass and sapling in Ⅱclass all are zero; adult individual number in Ⅲand Ⅳclasses accounts for 17. 39% and 4. 35% of total individuals,respectively; while mature individual number in Ⅴclass is the most with 60. 87% of total individuals;aging individual number in Ⅵclass also accounts for 17. 39% of total individuals. It is suggested that the B. sinensis population is a decline type population with insufficient numbers of seedling and sapling, so artificial breeding research should be strengthened to effectively expand its population size.