International Journal of Forestry Research / 2009 / Article / Tab 2

Research Article

A Bark Thickness Model for White Spruce in Alaska Northern Forests

Table 2

Parameters of the six area models and the statewide model to estimate the bark thickness of white spruce in Alaska northern forests.

ModelEstimated right hand side of equations nRMSE

Copper River Valley0.412* + 0.037 × dbh*0.771000.030
Delta area0.115* + 0.043 × dbh*0.691000.086
Fairbanks area0.239* + 0.034 × dbh*0.741000.054
Kenai Peninsula0.313* + 0.038 × dbh*0.761000.028
Mat-Su Valley0.314* + 0.028 × dbh*0.591000.042
Tok area0.247* + 0.034 × dbh*0.541000.070
Alaska 0.303* + 0.035 × dbh*0.636000.064

Note: Response variable is the thickness of bark (cm), dbh stands for the diameter-at-breast height (cm). that the coefficient is significant at 0.01 level. , coefficient of determination; , number of sampled trees; RMSE, root mean square error.

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