天然杨桦林的生长进程

The Growth Process of Poplar-Birch Natural Forests

采用固定标准地定位观测和临时标准地调查点面结合的方法,运用数量化I统计分析理论,将天然杨桦林的生长条件划分为IV个立地级,以I立地级为最佳。在立地分类的基础上,研究了天然杨桦林各立地级的生长进程,提出了天然杨桦林树高与胸径生长进程的3个阶段:速生期、均稳生长期和慢生长期。这为杨桦林的分类定向培育提供了理论的依据。

Combined oriented observation of permanent sample plots with investigation of temporary sample piots, the growth conditions of poplar - birch natural forests were divided into 4 site classes by using the statistical and analytical theory of quantitative model I , in which the site class I was the best. On the base of this, the growth process of poplar - birch natural forests in different site classes was studied. The growth processes of height and diameter at breast height were divided into three stages： fast growing period, stable growing period, and slow growing period. Results of this study provide a theoretical basis for the oriented cultivation of poplar - birch natural forests.