A Study on the Model of Theoretical Height-Diameter Curve of Pinus kesiya var. langbianensis

Based on the classic model of H=1.3+aD/(b+D), the height of dominant trees was introduced into the formula and a new model of the theoretical height-diameter curve for natural secondary forests of Pinus kesiya var. langbianensis was established as: H=1.3+(a₀+a₁Hd)D/(b+D). Slightly affected by site condition variation, and applied more simply than the classic one, the new model may more objectively demonstrate the varying rule of stem height corresponding to the diameter at breast height(D.B.H) at different site conditions. Therefore, the application field of height-diameter curve has been extended by the new model. Additionally, the new model has a clearer biological significance, for when the D.B.H is 0, the height H will be 1.3.