亚高山3种森林群落的结构特征与物种多样性

本文采用常规的群落学调查方法，研究了亚高山林区次生白桦（BF）、岷江冷杉（FF）和紫果云杉林（SF）的物种组成、叶面积指数（LAI）、年龄结构、胸径（DBH）分布和多样性指数等群落综合特征。结果表明：（1）BF群落中出现的雏管束植物有27科57属71种，FF群落中出现的维管柬植物有28科50属60种，SF群落中出现的维管束植物有27科36属39种；（2）BF、FF、SF群落的LAI分别为0．84（±0．11）、1．25（±0．30）和3．53（±0．22）；（3）FF、SF群落内的岷江冷杉、紫果云杉和方枝柏的树高、冠幅与胸径大小之间有显著的线性关系（R^2〉0．84），BF群落内的白桦树高、冠幅与胸径之间没有显著的线性关系（R^2〈0．10）。处于演替早期的森林群落物种多样性高于演替后期的物种多样性，演替后期的群落LAI高于演替初期的群落圳。可利用胸径大小与树高、冠幅之间的显著线性关系来评估亚高山“针叶树种”的冠幅和树高。

Research on Structural Characteristics and Species Diversity of Three Forest Communities in Subalpine Zones

In this paper, based on the traditional community investigation method, investigations were conducted on structural characteristics （ species composition, leaf area index （ LAI）, age-class structure, DBH distribution） and species diversity of three forest communities （that is, birch forest,fir-dominated forest and spruce-dominated forest） in subalpine zones. The results showed that： （ 1 ） as for vascular plants,there were 27 families,57 genera and 71 species in the birch forest （BF） ,28 families,50 genera and 60 species in the fir-dominated forest （FF） plots,and 27 families,36genera and 59 species in the spruce-dominated forest plots （SF）. （2）The LAI of BF,FF and SF were 0. 84（ ±0. 11） ,1.25（ ±0. 30） and 3.53 （ ± 0. 22）, respectively. （3） There was significantly linear correlation among tree height, crown width and DBH of needle trees （R^2 〉 0. 84）, but no significantly linear correlation for birch tress （ R^2 〈 0. 10）. Investigation results highlighted that there were lower species diversity, but higher LAI in laterstage successional forest communities than those in early-stage successional forest communities, and there was a significantly linear correlation among tree height, crown width and DBH of needle trees in subalpine zones.