文县杨生长过程分析及生长阶段划分

以甘肃省文县杨为研究对象,对其各生长因子(D1.3、H、V)的生长过程进行了分析,并采用有序样本分类法对其生长阶段进行了划分。结果表明:文县杨的D1.3、H及V生长过程均呈三次抛物线,但各生长因子的连年生长量和平均生长量最大值出现的年龄稍有差异,各阶段持续时间也不同;各生长因子平均生长量和连年生长量呈现不同的曲线类型;以D1.3、H及V三个因子进行有序样本分类,将文县杨生长过程可划分为幼龄阶段(1～4a)、速生阶段(5～11a)、稳定生长阶段(12～19a)、成熟阶段(20～27a)。

Increment process analysis and growing stage division of Populus wenxianica

Based on the trunk analysis data of the poplar species, Populus wenxianica collected in Wenxian, Gansu, the individual growing factors of diameter at breast heigh (DBH), height (H), volumn (V) were analyzed and the tree increment was divided into growing stages. The results showed that: the increment equations of DBH, H and V displayed cubic curves while the annual increment and the mean increment equations of each factor varied, and their maximum value appeared in different age periods. Because of the differences among the increment processes of DBH, H and V, we could aquire different results with different factors by means of ordinal data cluster. The increment processes of DBH, H and V were divided into four stages as follows: sapling stage (1～4a), fast growing stage (5～11a), stable growing stage (12～19a) and mature stage (20～27a).