Canadian Forest Service Publications
Recovering time trends in dominant height from stem analysis. 1996. Magnussen, S.; Penner, M. Canadian Journal of Forest Research 26: 9-22.
Issued by: Pacific Forestry Centre
Catalog ID: 4278
Availability: Order paper copy (free)
Site-index curves derived from stem analysis of trees with dominant height at the time of selection will underestimate dominant height of young trees and thus overestimate the performance and yield expectations of young stands. A simple model-based adjustment procedure is presented and tested on two artificial populations and two data sets from repeatedly measured plots. To recover a less biased height-age curve of dominant trees, estimates are needed of age-age correlations and the sampling intensity (standardized height difference) applied to the selection of site trees for stem analysis. Adaptation to different definitions of dominant height is possible. Results confirmed that the recovery procedure is very effective in reducing the relative bias. Bias reduction in excess of 40% can be expected during the first half of a rotation. Small but insignificant increases in bias were encountered during the second half of a rotation.