冀北山地白桦树种生长预测模型研究

Study on the Growth Prediction Model of Birch Species in the Mountainous Area of Northern Hebei

树高、胸径和冠幅等林分参数不但可以预测森林蓄积量、生物量、林分结构等,还是森林资源调查及经营效果评价的重要因子。建立树高、胸径和冠幅预测模型可以为森林资源质量和林木生长状况的评价提供支撑。本文以冀北崇礼山地白桦树高、胸径及冠幅的实地测量数据为基础,采用林木生长常用的4种基础回归模型和2种经验模型进行生长关系预测研究。在所选取的基础回归模型和经验模型中,确定Richards经验模型为预测该地区白桦树高-冠幅、胸径-冠幅及树高-胸径关系的最佳模型,R^(2)为0.8以上。同时模型简单的幂函数和线性函数的拟合度也较好,对冀北崇礼山地的白桦生长研究也具有较强的适用性,模型精度评价指标决定系数R^(2)与经典Richards模型相差在8%以内。基于Richards经验模型构建的冀北崇礼山地白桦树高、胸径和冠幅生长关系,模型的精度评价指标较高具有一定的统计学意义,对冀北崇礼山地白桦的林分参数预测有重要的参考价值。

Stand parameters such as tree height,diameter at breast height and crown width can not only predict forest volume,biomass,stand structure,etc.but also be important factors for forest resource investigation and management effect evaluation.It can provide support for the evaluation of forest resource quality and forest growth status establishing prediction models for tree height,diameter at breast height and crown width.Based on the field measurement data of Betula platyphylla Suk height,diameter at breast height and crown width in the Chongli Mountains of northern Hebei,four basic regression models and two empirical models commonly used in forest growth are used to predict the growth relationship.Among the selected basic regression models and empirical models,the Richards empirical model is determined to be the best model for predicting the relationship between tree height-crown width,diameter at breast height-crown width and tree height-diameter at breast height in this area,and R^(2) is above 0.8.At the same time,simple power function model and linear function model have a good fit,and they all have strong applicability for the study of the growth of Betula platyphylla Suk in the Chongli mountain area of northern Hebei.The model accuracy evaluation index determination coefficient R^(2) differ from the Richards empirical model by 8%.Based on Richards empirical model,the relationship among height,diameter at breast height and crown width of Betula platyphylla Suk in Chongli mountain of northern Hebei Province has high precision evaluation index,which has certain statistical significance,and has important reference value for the prediction of stand parameters of BetulaplatyphyllaSuk in Chongli mountain of northern Hebei.