福建琅岐岛台湾相思群落灌木层主要物种生态位与种间联结

Niche and Interspecific Association of Main Species in Shrub Layer of Acacia confusa Community in Langqi Island, Fujian Province

摘要:

为探究福建琅岐岛台湾相思(Acacia confusa)群落种间关系和群落演替动态，对其灌木层主要物种的生态位和种间联结特征进行了分析。结果表明，重要值和生态位宽度最大的物种为雀梅藤(Sageretia thea)，其竞争优势、环境适应能力最强; 灌木层主要物种的生态位相似性和生态位重叠较小，表明种间对环境资源的利用和要求存在较大差异，表现为较稳定的种间关系；灌木层主要物种的总体联结性为显著正联结，种对间正负联结比为1.72，检验显著率为7.35%，表明种对间联结程度较弱，独立性相对较强，物种竞争不激烈，群落处于相对后期且稳定的演替阶段；红锥(Castanopsis hystrix)与许多物种间存在垂直方向上对生境要求的互补性，生态位重叠较小，种间呈正联结关系；外来物种马缨丹(Lantana camara)与福建胡颓子(Elaeagnus oldhamii)存在一定的竞争，与灌木层其他主要植物之间的资源竞争不激烈，其对该群落的影响相对较小。琅岐岛台湾相思群落目前已发展为地带性的顶级群落，物种竞争不激烈，种间关系较稳定；而海岛上恶劣的环境和外来物种的扩散会导致植物生境资源短缺，迫使物种聚集在同一生境中共存，使植物对环境的利用程度减弱，因此需要加强控制外来物种数量并改善海岛生态环境，以维持海岛群落稳定发展。

关键词:琅岐岛;台湾相思群落;灌木层;生态位;种间联结

Abstract:

The niche and interspecific association of main shrub species in Acacia confusa community in Langqi Island of Fujian Province were analyzed to explore the interspecific relationship and succession dynamics of the community. The results showed that Sageretia thea had the largest importance value and niche breadth, and had the strongest competitive advantage and environmental adaptability. The niche similarity and niche overlap of the main species in the shrub layer were small, indicating that there were great differences in the utilization and requirements of environmental resources among the species, showing a relatively stable interspecific relationship. The overall association of the main species in the shrub layer was significant positive association, the positive and negative association ratio between species was 1.72, and the significant rate was 7.35%, indicating that the degree of association between species was weak, the independence was relatively strong, and the species competition was not fierce. The community was in a relatively late and stable succession state. There is vertical complementarity between Castanopsis hystrix and many other species, the niche overlap was small, and the interspecific association was positive. The alien species Lantana camara competed with Elaeagnus oldhamii to some extent, and the competition between Lantana camara and other main shrub plants was less intense, so its impact on the community was relatively small. The Acacia confusa community in Langqi Island had developed into a zonal climax community, the species competition is not intense, and the interspecific relationship is stable. The harsh environment and the spread of alien species on the island will lead to the shortage of plant habitat resources, forcing species to gather in the same habitat coexistence, so that the degree of plant utilization of the environment is weakened. Therefore, it was necessary to control the number of alien species and improve the ecological environment of islands in order to maintain the stable development of island communities.

Key words:Langqi Island;Acacia confusa community;Shrub layer;Niche;Interspecific association