山西五台山主要针叶树种树高—胸径曲线模型研究

Developing models for height-diameter curves of main conifer species of Wutai Mountain in Shanxi Province

建立适用于五台山地区主要针叶树种的最优树高—胸径曲线模型,旨在为五台山地区主要针叶树种,尤其是为山西省重点保护植物臭冷杉的森林调查和经营管理提供参考。本研究在山西臭冷杉省级自然保护区内建立2个10000 m^(2)的固定样地,以臭冷杉、华北落叶松和青杄为研究对象,选择Richard,Logistics,Weibull,Korf,二次多项式,Schumacher,Sloboda,幂函数等8种树高—胸径曲线模型作为备选模型,以决定系数(R^(2))和均方根误差(RMSE)作为模型拟合效果的评价指标,利用检验数据进行精度检验,从中筛选出拟合精度最佳的模型。结果表明:8种模型对臭冷杉、华北落叶松和青杄的树高与胸径关系的拟合效果均较好,决定系数R^(2)均在0.700以上。二次多项式模型H=0.728+0.939 D-0.010 D 2是臭冷杉的最优树高—胸径曲线模型;华北落叶松和青杄的最优树高—胸径曲线模型均为Sloboda模型,其中华北落叶松最优树高—胸径曲线模型为H=34.087 e^(-4.787)e-^(0.485 D 0.447),青杄最优树高—胸径曲线模型为H=32.383 e-^(3.501)e-^(0.195)D^(0.679);Schumacher模型的拟合效果最差。

The optimal height-diameter curve model for main conifer species was established to provide reference for forest investigation and management of main conifer species in Wutai Mountain,especially Abies nephrolepis which is the key protected plant in Shanxi Province.In this study,two permanent sample plots of 10000 m^(2)were established in Shanxi Abies nephrolepis Provincial Nature Reserve.Taking A.nephrolepis,Larix principis-rupprechtii,and Picea wilsonii as research objects,eight height-diameter curve models,i.e.,Richard,Logistics,Weibull,Korf,Quadratic polynomial,Schumacher,Sloboda,and Power function were selected as alternative models,while the coefficient of determination(R 2)and root mean square error(RMSE)were used as the evaluation indicators of the pros and cons of the model.After then,the accuracy was tested by using the test data.from which the model with higher goodness of fit was selected.The results showed that the eight models had a good fitting effect on the relationship between tree height and DBH of A.nephrolepis,L.principis-rupprechtii,and P.wilsonii.The coefficient of determination(R^(2))of the main conifer tree species were higher than 0.700.The quadratic polynomial model,H=0.728+0.939 D-0.010 D ^(2),was the optimal height-diameter curve model of A.nephrolepis.Sloboda model was the optimal height-diameter curve model of L.principis-rupprechtii and P.wilsonii.The optimal height-diameter curve model of L.principis-rupprechtii was H=34.087e^(-4.787 e-0.485 D 0.447).The optimal height-diameter curve model of P.wilsonii was H=32.383 e^(-3.501 e-0.195 D 0.679).Schumacher model had the worst fitting effect.