A Site Index Formula for Peatland Black Spruce in Ontario

Site index formulas were derived for peatland black spruce (Picea mariana [Mill.] B.S.P.) in northern Ontario based on stem analysis of 60 dominant and codominant trees. Nonlinear regression analysis and a biological growth function were employed to express both height as a function of site index and stand age and also site index as a function of stand height and age. Analysis of results indicates that peatland black spruce has a different pattern of height growth than that shown by Plonski's site index curves, particularly for site indices less than 8 m and stands older than 80 years.