异龄林生长的动态分析——兼小兴安岭和牡丹江林区冷杉异龄林的生长分析

异龄林既是一个自然生态系统,又是一个复杂的森林经营系统。一个经营工作者要对异龄林进行高效率的经营,就必须掌握现实林的动态变化规律,以便有目的地制定经营措施。异龄林系统从经营角度出发,可以划分成如下三个组成单元:进界生长量、向上生长量和枯损量。上述三个单元的相互作用构成了异龄林系统的动态变化规律。本文的主要目的就是通过对上述三个生长单元的动态进行模拟,寻找出异龄林的动态变化规律,所用方法是对每个生长单元用多个数学模型进行拟合,再通过统计量分析和实际验证从中选出最理想的模型,并据此对现实异龄林的动态进行预测。证明了以曲线形式反映异龄林的动态变化远优于线性形式。所用材料取自黑龙江省小兴安岭和牡丹江林区的冷杉(Abies nephrolepis)为主的异龄针阔混交林。

DYNAMIC ANALYSIS OF UNEVEN-AGED FOREST STAND GROWTH

Uneven-aged forest is not only a natural ecosystem, but a complicated forest management system. This system can be divided into three components-Ingrowth, Mortality, and Upgrowth in the view of management. The interaction of the three components made Uneven-aged stand into regular dynamics. Nonlinear models were developed for prediction of periodic ingrowth,mortality,and upgrowth by 4-cm diameter classes in north eastern mixed forest stand of Heilongjiacg province. Models were constructed using 5-year growth records on 35 permanent plots and 15 temporary plots with a br.oad range of age and size classes distributions. The fir (Abies nephrolepis) in all plots is more than 50 percent. The dynamic transition of uneven-aged forest stand was predicted using this group of models; In the last section of this paper, consideration in the formulation of the models and a disscussion of their use and limitation are also presented. It is indicated that nonlinear models are better than linear models.