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四川中部绵阳官司河流域的半自然型林是长江中上游地区防护林的一个较典型类型 .本文以它为研究对象 ,对群落的物种多样性及其在次生演替过程中的动态变化趋势进行了初步研究 ,并结合影响多样性的几个主要环境因子进行了相关性分析 .结果表明 :( 1)现阶段该防护林的植物种类组成和群落结构均较简单 ,松、柏、栎混交的针阔叶林占绝对优势 ,其物种多样性较小 ,但随着群落次生演替的进展 ,各层次的多样性趋于增加 ;( 2 )用灰色系统理论的关联度分析方法研究群落的物种多样性与主要环境因子的相关性是可行的 .经测定 ,研究区的土壤 pH值、外界干扰度和土壤含水量等指标对防护林的物种多样性有显著的影响 .图 2表 3参 16
The semi-natural forest in Mianyang, Guizhou Province, central Sichuan Province is a typical type of shelterbelt in the middle and upper reaches of the Yangtze River.The paper takes it as the research object, and conducts a survey on the species diversity of the community and its dynamic change trend in the secondary succession The results showed that: (1) The plant species composition and community structure of this shelterbelt are relatively simple at the present stage, and the needle of Pinus, cypress and oak The broadleaf forest occupies the absolute superiority and its species diversity is small. However, with the secondary succession of the community, the diversity at all levels tends to increase. (2) Using the gray system theory, the correlation analysis method is used to study the species The correlation between diversity and major environmental factors is feasible.It is determined that the indexes of soil pH, external disturbance and soil water content in the study area have a significant impact on the species diversity of shelterbelts.