极小种群野生植物浙江安息香的生态位和种间关系

Niche and interspecific relationship of the wild plant Styrax zhejiangensis with extremely small population

通过对分布于浙江省建德林场泷江林区桃花坞的浙江省特有极小种群野生植物浙江安息香(Styrax zhejiangensis)所在群落进行实地调查,采用Levins、Shannon、Pianka公式对浙江安息香的生态位特征进行分析,并运用χ^2检验、联结系数(association coefficient, AC)、共同出现百分率(percentage of co-occurrence, PC)进行种间联结性分析,为浙江安息香的保护提供理论依据。结果表明:1)浙江安息香的重要值为10.74%,位居灌木层物种第3位,是所在群落灌木层的优势种群之一。2)浙江安息香的Levins和Shannon 2种生态位宽度均较大,分别为6.557和1.977。3)与浙江安息香生态位重叠值最大的是柃木(Eurya japonica),说明浙江安息香与柃木具有相似的环境要求,但其之间有负联结倾向,说明二者在利用环境营养空间上会产生竞争并争夺资源。本研究认为,浙江安息香在其生长的阴湿环境下具有较强的生态适应能力,反映出该种群对生长环境的特殊要求。在资源不足的情况下,浙江安息香与箬竹(Indocalamus tessellatus)、柃木、大青(Clerodendrum cyrtophyllum)和冬青(Ilex chinensis)等产生资源竞争,是造成浙江安息香数量少的主要原因。本研究结果可为浙江安息香的保护提供科学理论依据。

Styrax zhejiangensis distributed in Taohuawu,Longjiang Forest Area,Jiande Forest Farm,Zhejiang Province,is a unique wild plant with extremely small population in Zhejiang Province.Based on the field investigation on the communities of S.zhejiangensis,the niche characteristics of S.zhejiangensis was analyzed by Levins’,Shannon’s and Pianka’s formulas,and the interspecific association was analyzed byχ^2 test,association coefficient(AC),and percentage of co-occurrence(PC)to provide a theoretical basis for the protection of S.zhejiangensis.The results were as follows:1)Being one of the dominant species in shrub layer in its community,S.zhejiangensis’s important value was 10.74%,which ranked the third in the species of shrub layer.2)Styrax zhejiangensis had larger niche breadths calculated by the Levins’and Shannon’s formulas,which were6.557 and 1.977,respectively.3)Eurya japonica had the biggest niche overlap value with S.zhejiangensis,which indicated that S.zhejiangensis had similar environmental requirements with E.japonica.However,there was a negative connection tendency between them,indicating that there was competition in the use of environmental nutrition space and the struggle for resources between them.The strong ecological adaptability of S.zhejiangensis in the humid environment revealed the special requirements of S.zhejiangensis for its growth environment.The main reasons for the scarcity of S.zhejiangensis were that it had competition for resources with Indocalamus tessellatus,E.japonica,Clerodendrum cyrtophyllum,Ilex chinensis and so on in terms of lacking resources.In summary,the above results provide a scientific and theoretical basis for protection of S.zhejiangensis.