Comparison and Selection of Correlation Models between Root Diameter and Breast Height Diameter of Pinus densata in Northwest Yunnan
A total of 862 Pinus densata sample trees were surveyed in northwest Yunnan,including 824 effective sample trees.618 modeling sample trees were systematically extracted,and 206 inspection sam-ple trees were tested.10 univariate linear or nonlinear regression equations were selected to fit the model parameters of breast height diameter D and root diameter DR,and their applicability was tested.The re-sults showed that the model D=-2.710599+0.938673DR-0.000911DR2 had a relatively small sum of squared deviations(SSR)value,a total relative error(RS)of 0,a correlation coefficient(R2)of 0.987,an estimation accuracy of 99.44%,the residual plot was most uniformly and randomly distributed around the horizontal axis,and the maximum coefficient of variation of model parameters was 32.3%,in-dicating the stability of the model.There was no significant difference between the measured and esti-mated values of the test sample,indicating that the model was optimal.
Pinus densataroot diameterbreast height diametercomparison and selection of correlation modelsnorthwest Yunnan
NETL
NSTL
万方数据
