陕北南部侧柏林演替时期的划分及其特征

DIVISION OF SUCCESSIONAL PHASE IN THEPLATYCLADUS ORIENTALIS FOREST IN THE SOUTHLOESS PLATEAU OF THE NORTHERN SHANXI PROVINCE

用模糊聚类分析和对应因子分析方法将陕北南部森林次生演替侧柏林阶段划分为３个时期：初期、中期和晚期，各时期几个主要的群落特征和土壤特征的变化证实了这种划分的合理性。同时，结果还暗示在生境不一致的情况下以空间变化代替时间变化来研究群落演替有时可能是危险的。

By using fuzzy clustering analysis and correspondence analysis,the Platycladus orientalis forest stage of secondary forest succession in the south loess plateau of the northern Shanxi province was divided into three phase in this paper:initial phase,medium phase and terminal phase.This conclusion was certified by the change of community structure and soil characteristics in each phase and implied that it maybe misleading to study community succession through replacing time change with spatial change.