Predicting Site Indices of Japanese Cedar Plantation in Niigata Prefecture using Environmental Factors

Abstract

The objectives of this study were (a) to evaluate the correlation of environmental factors with the site index of Japanese cedar, and (b) to develop the best-fit equation model for the site index. Multiple regression models for a site index of sugi plantation in Niigata Prefecture were constructed using environmental factors as independent variables. The environmental factors used were climate data (snow depth), soil type data and topographical data (aspect, slope, elevation, hillshade, distance from ridge, wetness and curvature). Through a backward stepwise procedure, the elevation, hillshade and soil type were selected for a best-fit regression model. In this model the multiple correlation coefficient was 0.523, and standard error estimate 2.84m.