[Niche and interspecific association of dominant tree species in Michelia odora community].

In order to understand the interspecific and ecological relationships of Michelia odora (extremely small population) community and strengthen the protection of wild M. odora resources in Junzifeng Nature Reserve, we studied the niche characteristics and interspecific associations of dominant tree species. The results showed that M. odora, Machilus chekiangensis, Schima superba, and Alniphyllum fortunei had obvious niche breadth advantages, which were the constructive species of the community. Among the 190 groups of species pairs among the 20 dominant tree species, 50.5% of species pairs had niche overlap value greater than 0.5. The degree of ecological niche differentiation among species was general. M. odora had large niche overlap with other 19 species, indicating a competitive risk when resources were insufficient. The overall associations of dominant tree species were significantly positive, indicating the community was at the late stage of relatively stable succession. The results ofχ2 test, asso-ciation coefficient, and Pearson correlation coefficient showed that all the significance ratios of interspecific association were lower, and that the independence among species was relatively strong. There was a positive correlation between interspecific association and niche overlap. The M. odora community was relatively mature, with full utilization of resources and stable interspecific relationship. To promote the rejuvenation and create a good habitat of M. odora population, the population size with large overlap with M. odora niche and significant negative association could be appropriately limited, while that with positive interaction could be increased.为了解君子峰自然保护区极小种群观光木群落的种间关系和生态联系,加强观光木野生资源的保护,对群落优势树种的生态位特征和种间联结性进行研究。结果表明: 观光木、浙江润楠、木荷、赤杨叶的生态位宽度优势明显,是主要建群种;20个优势树种的190组种对中,有50.5%的种对生态位重叠值大于0.5,物种间生态位分化程度一般;观光木与其他19个物种生态位重叠度普遍较高,当资源不足时,有竞争风险;优势树种的总体联结性表现为显著正联结,群落处于相对稳定的演替后期;χ2检验、联结系数和Pearson相关系数检验结果均显示,种间联结性的显著率极低,种间独立性较强;种间联结性与生态位重叠之间呈正相关。君子峰观光木群落较为成熟,资源利用充分,种间关系稳定,为促进观光木种群恢复和壮大,可适当限制与观光木生态位重叠度大、有显著负联结的种群规模,提高与之有正相互作用的物种比例,为观光木营造良好的生境。.