桉树混交林生长特性及林下植物多样性分析

Analysis on Growth Characteristics and Understory Plant Diversities of Eucalypt Mixed Plantations

为给桉树混交林营建提供参考,采用典型样地法,研究尾巨桉(Eucalyptus urophylla×E. grandis)×马尾松(Pinus massoniana)×格木(Erythrophleum fordii)(MPEE)、尾巨桉×马尾松×大叶栎(Castanopsis fissa)(MPCE)、尾巨桉×马尾松(MPE)和尾巨桉纯林(PE)4种林分的生长特性及灌木和草本层物种组成和多样性变化规律。结果表明,MPE中的桉树单株材积显著高于其他林分,表明MPE对桉树单株生长有促进作用。混交林中,MPCE的总蓄积量最高。4种林分林下植物群落基本一致,共有41科64属68种植物;MPE混交林下植物种类较丰富,共有31科44属45种植物,其多样性指数整体高于其他林分类型。在尾巨桉纯林改造和升级过程中,应考虑营造尾巨桉×马尾松混交林,更有利于桉树生长和生态环境的稳定。

In order to provide reference for construction of eucalypt mixed plantations,growth characteristics of Eucalyptus urophylla×E.grandis×Pinus massoniana×Erythrophleum fordii(MPEE),E.urophylla×E.gran⁃dis×P.massoniana×Castanopsis fissa(MPCE),E.urophylla×E.grandis×P.massoniana(MPE),E.urophylla×E.grandis pure plantation(PE)as well as species compositions and diversities of shrub and herb layers were studied by typical plot method.Results showed that individual volume of eucalypt in MPE was significantly higher than that in other stands,indicating that MPE could promote individual growth of eucalypt.MPCE had the highest total accumulation among mixed plantation.Understory plant communities of four stands were basi⁃cally the same,with 68 plant species belonging to 41 families and 64 genera.Plant species under MPE were abundant with 45 plant species belonging to 31 families and 44 genera.Diversity indexes of MPE were higher than those of other stands as a whole.In process of transformation and upgrading of eucalypt pure plantation,construction of E.urophylla×E.grandis×P.massoniana mixed plantation should be considered,which was more suitable for eucalypt growth and stability of ecological environment.