Evaluating height-age determination methods for jack pine and black spruce plantations using stem analysis data

Abstract

Six height-age determination methods (Graves, Lenhart, Carmean, Newberry, ratio, and ISSA) were evaluated for their accuracy and sensitivity to sample size in determining height-age pairs using stem analysis data from plantation-grown black spruce (Picea mariana [Mill.] B.S.P.) and jack pine (Pinus banksiana Lamb.) trees from Ontario, Canada. Twenty-three disks (sections) were used from 102 jack pine and 93 black spruce trees each for evaluation. The Graves, ratio, and Newberry methods were unbiased for determining height-age pairs for both black spruce and jack pine across the site productivity gradient and different crown classes. However, on the basis of the magnitude of height prediction bias, reconstructed tree profiles, and the amount of information required for height-age determination, the Graves method with at least 13 stem sections is recommended for height-age determination. Copyright © 2010 by the Society of American Foresters.