基于非线性度量误差的湿地松生长模型

A Growth Model for Pinus elliottii Based on the Nonlinear Measurement Error Method

基于样地调查数据选用理查德方程和Schumacher为基础模型,采用非线性度量误差方法求解模型,在最优基础模型中引入哑变量,建立可兼用于采脂与未采脂林分的湿地松人工林生长模型。结果表明:两类基础模型的拟合效果均较好,模型决定系数均超过了0.9,其中Schumacher模型为最优基础模型。在该模型引入哑变量后,拟合出的断面积与蓄积量模型决定系数提升为0.9927与0.9972,模型精度提升为96.1%与97.2%。对哑变量模型做配对t检验,其p值均大于0.05,表明模型可用于估测采脂与未采脂不同经营措施湿地松林分断面积与林分蓄积量,可作为湿地松林分蓄积量测算与林分经营的依据。

Based on the plot survey data,the Richard equation and the Schumacher model were used to fitting.The model was fited by nonlinear metric error method,the result showed the fitting effects of the two basic models were good,and the model determination coefficients were all over 0.9.The Schumacher model was the optimal basic model.After the dummy variable was introduced into the model,the calculated coefficient of the fracture area and the accumulation model was increased to 0.9927 and 0.9972,and the model accuracy is improved to 96.1%and 97.2%.Paired t-tests were performed on the dummy variable model,and the p-values were all greater than 0.05,indicating that the model can be used to estimate the splitting area and stand volume of Pinus elliottii forests with different management measures,such as fat-harvesting and non-removing fat,in order to measure the stock of Pinus elliottii forest stand.The forest management model provides a reference.