APPLICATION OF THE KALMAN FILTER MODEL IN SITE INDEX EQUATION CONSTRUCTION

Extension of the Richards biological growth function has been applied extensively to describe height growth patterns or to develop site inde x equations. We introduce a linear filter model to achieve the same go als. Although derivation of the filter model involves more computation , it compares well with the Richards growth model in accuracy when app lied to a black spruce (Picea mariana (Mill.) B.S.P.) stem analysis da ta set from northern Ontario. The main advantage of the filter model, however, is that it can be used as a base-age invariant site index mod el.