基于长期历史数据的直径结构预测模型

The Prediction Model of Diameter Distribution Based on Long-Term Investigation Data

系统的结构决定系统的功能。森林是复杂的生态系统,作为系统,它理所当然地遵循着结构决定功能这一系统法则（惠刚盈等,1995）。林分的直径结构是体现林分特征最基础也是最重要的因子之一（亢新刚等,2003）。

Diameter distribution is one of the key factors to reflect the characteristic of forest stand.Based on the longterm investigation data on the Jingouling Forest Farm which belongs to the Wangqing Forestry Bureau in Jilin Province,negative-exponential function was used to model the diameter distribution in different years.The parameters a and K were calculated.Result shows that a and K were decreasing along time.Thus,a and K were supposed as functions of time.After the estimating of a and K,the diameter distribution model was established.Then we used this model to predict the diameter distribution,and compared with the observed diameter distribution.Result shows the model we draw in this study is well-behaved.The diameter distribution was usually used to present the instant structure of stand in previous study.This study shed light on the prediction model of diameter distribution,and also it is very important in forest modeling.