Study On The Stand Growth And Yield Model Of Larix Principis-rupprechtii Plantation Based On Forest Vegetation Simulator (FVS)

In order to achieve the goal of the FVS system software’s localization,and build up the growth and yield model systems of the species in our nation, this article take the Larix principis-rupprechtii Forests of Hebei forestfloor as the research object, using the methods of stepwise linear regression and nonlinear regression and so on to fit model parameters, to establish5core growth and yield models of FVS system——DBH-height model, crown width (crown) models, DBH growth model, tree height growth model and volume model, which based on large numbers data of temporary stands and analysis wood and using the model forms of FVS system. All the model’s determination coefficients were reach the significant level, using t-test and the residual distribution of the test method to test the above model respectively, the test results showed that the predicted values and measured values was no significant difference, the residual distribution to comply with normal distribution, model fit well. Among the models, the DBH growth model and tree height growth model were the first time to set up the5-year growth as the dependent variable in our nation.In addition, trying to use collinearity diagnostics to screen the independent variable in the modeling process. The results show that, under the premise of using a large number of relatively independent of each independent variable, should to use collinearity diagnostics to decrease powers, otherwise, should be directed to the regression.