滨海防护林木麻黄和花吊丝竹混交林群落的种间关联和生态位分析

Interspecific Associationand Niche of Mixed Forest Communities of Casuarina equisetifoliaandDendrocalamus minor var.amoenusin the Windbreak of Sandy Coast

为了解东山岛滨海防护林木麻黄(Casuarina equisetifolia)和花吊丝竹(Dendrocalamus minorvar.amoenus)混交林群落的稳定性,采用样方法调查分析群落的种间关联和生态位。结果表明,群落总体的种间联结呈现不显著的正关联(VR=1.72,W=20.625),表明群落处于不稳定的动态演替状态。花吊丝竹和马缨丹(Lantana camara)、梵天花(Urena procumbens)和木麻黄表现出非常紧密的关联性和共现性(PC≥0.7,OI≥0.8,DI≥0.8)。马缨丹等外来植物生态位宽度较高,与花吊丝竹具有较高的生态位重叠,从而与花吊丝竹具有较高的正联结,使得群落处于不稳定状态。滨海防护林生境单一,优势物种习性相似,使花吊丝竹与多数物种形成强的正关联。受到环境资源的限制,强的正关联与物种生态位宽度较大有关。种对间强的正关联以及外来物种潜在的生存优势可能是影响群落稳定性的重要因素。

In order to understand the stability of mixed forest community of Casuarina equisetifoliaandDendrocalamus minor var.amoenusin the coastal windbreak of Dongshan Island,China,the inter-specific association and niche of the community was analyzed by using quadrat method.The results showed that there was no significant positive correlation among inter-specific associations as a whole(VR=1.72,W=20.625),indicating that the community was in an unstable dynamic succession state.Two species pairs;D.minor var.amoenusand Lantana camara,U.procumbensand C.equisetifoliahad high association and co-occurrence(PC≥0.7,OI≥0.8,DI≥0.8).The niche widthof invasive plant L.camarawas high,and the niche overlap withD.minor var.amoenuswas high,showing high positive correlation,making the population in an unstable state.The habitats of the coastal windbreak was simple,and the habits of dominant species were similar,so there was a strong positive interspecific association between D.minorvar.amoenusand other most species.Restricted by environmental resources,the strong positive association was related to the largeniche width of species.The strong positive interspecific association of species pairs and the potential competitive advantage of alien species might be an important factor affecting the stability of the community.