Predicting Total Height from Diameter Using Nonlinear Models in Pinus roxburghii

Height of the trees is not only used to estimate the product available from trees and to determine the productive capacity of the particular land but also used in forest management and research activities. In this research, predictability of total height from diameter at breast height for chir-pine ( Pinus roxburghii ) by using nonlinear models was examined. Total height and diameter at breast height of 180 trees were measured by using Suunto Clinometer and diameter tape respectively. The measured data were subjected to previously developed robust and strong statistical models, and evaluated by using different test statistics. Among those, H = e (-0.276) D 0.925 explained the greatest proportion of variations of height (R 2 adj .=0.910) and minimum root mean square error (RMSE=1.221) and showed desirable behavior of flexibility and robustness. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 147-152 DOI: http://dx.doi.org/10.3126/njst.v14i1.8935