Early Height Growth and Site Index for Planted Red Pine in North Central Ontario

Abstract Height-growth, site-index curves, and growth intercepts were developed from internode and stem-analysis data using dominant trees in 25 plots located in red pine plantations aged 26 to 37 yr. Height-growth curves were based on breast-height age because growth below breast height (1.3 m) was slow and erratic. Growth intercepts using the first three to five internodes above 1.5 m gave the best estimates of site index (dominant height at 20 yr breast-height age)for trees that were between 3 and 5 yr breast-height age; site-index estimation equations gave the best estimates for trees older than 10 yr breast-height age. These computed height-growth curves and growth intercepts and observed site index in north central Ontario were similar to other regions. The excellent growth observed in this study suggests that red pine should be given greater emphasis in future reforestation programs in north central Ontario. North. J. Appl. For. 12(1): 23-29.