川中半自然型防护林演替过程中的物种多样性

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

STUDY ON SPECIES DIVERSITY UNDER SECONDARY SUCCESSION OFSEMI-NATURAL PROTECTED FOREST IN CENTER OF SICHUAN

The semi-natural forest of Guansi River watershed, located in the central section of Sichuan Province, is one of typical protected forest types in the middle-upper stream of the Changjiang River. This paper dealt with the species diversity of the protected forest in this region and its trends in the course of secondary succession. Moreover, the correlative grade between the species diversity and several main environmental factors was also studied. The results showed that (1) the species diversity of the protected forest seemed low at present, and the mixed forest of pine-cypress-oak was the absolutely dominant community type, but the species diversity of different layers ( tree, scrub and herb layer, respectively) trended to become higher with the advance of the secondary succession; (2) the study of relationship between the diversity of woody plants and 9 environmental factors in each plot proved that the species diversity of the protected forest in the study area was obviously affected by soil pH value, external interference and soil moisture. Fig 2, Tab 3, Ref 16