基于生长模型的林地“一张图”林分因子更新研究

Study of Data Updating for Forestry Land Resources on Single Map Based on Growth Model

林地“一张图”是森林资源管理体系的重要平台,运用林分生长模型对林地“一张图”林分因子更新具有现实意义。基于昆明市第4次森林资源二类调查数据,建立了24个树种(组)林分生长模型,通过模型链接实现林分平均树高、平均胸径、每公顷株数、每公顷蓄积和平均蓄积生长量的过程动态模拟。树高生长模型拟合优度R^2介于0.21~0.64之间,胸径生长模型拟合优度]R^2介于0.37~0.78之间,蓄积生长模型拟合优度R^2介于0.44~0.92之间;林分生长模型反演昆明市有林地蓄积量预测值与观测值相差37万m^3,云南省蓄积平均生长率反演昆明市有林地蓄积量预测值与观测值相差291万m^3。建立的24个树种(组)林分生长模型,能满足林地“一张图”林分因子更新要求,能动态掌握森林资源消长变化,可为林业政策的制定提供依据。

Single map of forestry land resources is important for forest resources management.Application of stand growth model in updating stand factors of forest resources is meaningful in forest management practices.24 growth models were established based on data set of 4th forest resources survey in Kunming,which illustrate dynamic growth process of average stand height,DBH,number of trees per hectare,volume per hectare and mean increment of volume by model link.Fitting goodness of height growth is between 0.21 and 0.64.Fitting goodness of DBH growth is between 0.37 and 0.78.Fitting goodness of volume growth per hectare is between 0.44 and 0.92.There is a difference of 0.37 million cubic meters between predictions through stand growth model and observations.There is a difference of 2.91 million cubic meters between predictions through volume growth rate in Yunnan province and observations.24 models for different tree species could meet the requirement of data updating for single map of forestry land,which could provide support for policy making in forest management by mastering fluctuation of forest resources.