粉绿柯群落优势乔木的生态位与种间关联分析

Niches and interspecific associations of dominant trees in a Lithocarpus glaucus community

为更好地监测与保护濒危植物粉绿柯(Lithocarpus glaucus)种群,以广东阳春鹅凰嶂省级自然保护区的粉绿柯群落为研究对象,采用生态位测定法、方差比率法、χ^(2)检验等方法,结合Pearson相关系数和Spearman秩相关系数检验综合分析粉绿柯群落乔木层31种优势树的生态位和种间相互关系。结果表明:粉绿柯的重要值最大,生态位宽度优势明显(排名第2),仅次于天料木(Homalium cochinchinense)。粉绿柯与其余优势树种组成的30个种对中,25对种对的生态位相似性比超过0.50,26对种对的生态位重叠值超过0.50,说明粉绿柯与其余优势种生态习性相似较高。当资源有限时,各树种间存在竞争风险。研究区内31种优势乔木树种总体呈显著正关联,表明该地区粉绿柯群落处于相对成熟的演替后期阶段。χ^(2)检验、Pearson相关系数和Spearman秩相关系数检验综合分析结果表明,乔木层优势树种间的种间关联较为松散,各个树种倾向于独立分布。研究区粉绿柯群落目前正处于演替的后期阶段,资源利用充分,种间相关性较弱,各物种间存在竞争风险;粉绿柯种群生存状况良好,在没有人类活动干扰的条件下,粉绿柯有较强的生存潜力。为促进粉绿柯种群的恢复与壮大,可提升林内光照强度,适当移除群落中干枯及被风力摧倒的树木,限制与其生态位重叠程度大、有显著负关联的种群规模,以优化粉绿柯种群的生长环境。

We investigated the population of Lithocarpus glaucus,an endangered plant species,within the provincial nature reserve E’huangzhang,Yangchun,Guangdong,to enhance their monitoring and conservation efforts.Employing ecological niche measurements,variance ratio analysis,χ^(2) tests,and a combination of Pearson′s and Spearman′s rank correlation coefficients,we comprehensively analyzed the ecological niches and interspecific interactions among 31 dominant tree species in the L.glaucus community.Our findings reveal that L.glaucus ranks seconds in importance,after Homalium cochinchinense,with a significantly wide ecological niche.Among the 30 pairs of tree species combinations involving L.glaucus,the niche similarity ratios of 25 pairs were over 0.50,and the niche overlap values of 26 pairs were over 0.50,indicating high ecological similarity and overlap among the dominant species,suggesting potential competition in a resource scarce environment.Overall,the 31 dominant tree species exhibit significant positive associations,indicating that the L.glaucus community is in a relatively mature successional stage.The results of theχ^(2) test as well as Pearson′s and Spearman′s rank correlation coefficients show that the interspecific associations among dominant canopy species are relatively weak,suggesting independent distribution patterns.In summary,the L.glaucus community is currently in a late successional stage,utilizing resources efficiently,with weak interspecific correlations and potential competitive risks.The L.glaucus population thrives in environments free from human disturbances,demonstrating strong survival potential.To enhance their recovery and growth,we recommend increasing light intensity within the forest,selectively removing dead or wind-felled trees,and managing species population sizes with significant negative associations to optimize the growth environment.