珍稀濒危植物细果秤锤树群落物种组成与生态位分析

  目的  基于群落生态学研究濒危植物细果秤锤树Sinojackia microcarpa的生境适应性和种间相互关系，有利于展开细果秤锤树的保护与扩繁。  方法  基于浙江省建德市细果秤锤树典型种群保护样地的群落调查与生境数据，分析物种组成、生态位特征、优势种种间联结关系。  结果  ①细果秤锤树样地内共记录到胸径≥1 cm的木本植物401株，隶属于35科50属51种。样地上层木中重要值≥1%的物种共16种，重要值排在前4位的物种从大到小依次为毛竹Phyllostachys edulis、柏木Cupressus funebris、板栗Castanea mollissima和细果秤锤树，这4个物种重要值之和为49.85%。②细果秤锤树与上层木树种樟树Cinnamomum cmphora、与下层木树种檵木Loropetalum chinensis的生态位相似性最高，且生态重叠值大于0.5。细果秤锤树与茶Camellia sinensis、檵木、毛花连蕊茶Camellia fraterna等物种负联结，表明它们之间存在显著的竞争关系。  结论  个体数量稀少，生境条件较差，在资源受限时种间竞争激烈等是细果秤锤树濒临灭绝的关键原因。表8参33

Species composition and niche of Sinojackia microcarpa, a rare and endangered plant

  Objective  The purpose is to study the habitat adaptability and interspecific relationship of the endangered plant Sinojackia microcarpa based on population ecology, which is beneficial to its effective protection and propagation.   Method  Based on the community survey and habitat data of typical population of S. microcarpa in Jiande, Zhejiang Province, the species composition, niche characteristics, and the linkage between dominant species were analyzed.   Result  (1) A total of 401 woody plants with diameter at breast height (DBH)≥1 cm were recorded, belonging to 51 species, 50 genera, and 35 families. There were 16 species with an important value≥1% in the upper wood of the sample site, and the top 4 species with an important value ranging from large to small were Phyllostachys edulis, Cupressus funebris, Castanea mollissima, and S. microcarpa. The sum of the important values of these 4 species was 49.85%. (2) S. microcarpa had the highest niche similarity with the upper wood species such as Cinnamomum cmphora, as well as the lower wood species such as Loropetalum chinensis. The ecological overlap value was greater than 0.5. The negative interspecific association between S. microcarpa, Camellia sinensis, Loropetalum chinensis and Camellia fraterna suggested that there was significant competition between them.   Conclusion  Rare individuals, poor habitat conditions, and fierce interspecific competition when resources are limited are the key reasons for the extinction of S. microcarpa. Ch, 8 tab. 33 ref.]