太白红杉林径级和龄级结构的研究

在秦岭太白山，选取太白红杉3个林型组中的8种林型，设置20个样地，用样方分析法进行调查，共做样方180个，主要分析了太白红杉8种林型的径级和龄级结构及其密度变化规律等，根据它们的径级和龄级结构表现特征，划分为3种类型，结果表明用径级和龄级对太白红杉林进行客观描述存在着一致性，太白红杉年龄均值浮动区间的大小，说明太自红杉林种群在发育上存在着时间差异，还对造成太白红杉8种林型的这一径级和年龄结构的形成原因进行了探索，提出了相应的保护策略。

Size-class and Age-class Structures of Larix chinensis Forests

In Qinling Taibai Mountain,8 Larix chinensis forest-types were selected from 3 Larix chinensis forest-type groups and 20 stands were set up.180 plots in Larix chinensis population were investigated with the sampling method.The 8 Larix chinensis forest-types's structures of size-class and age-class and density changing were principally analyzed.Based on the appearance feature of size-class and age-class structures,the natural forests were classified into 3 types.The results showed that there was consistency in using size-class or age-class to objectively describe Larix chinensis forests and the fluctuating range of the average-age of Larix chinensis forests indicated that there were growth time differences among different Larix chinensis forest-types.In this study,the forming reasons of the size-class and age-class structure were probed,and some corresponding protecting strategies were proppsed.