Canadian Forest Service Publications

Quantifying growth responses of black spruce and jack pine to thinning within the context of density management decision-support systems. Newton, P. 2015. Open Journal of Forestry 5: 409-421.

Year: 2015

Available from: Great Lakes Forestry Centre

Catalog ID: 36458

Language: English

CFS Availability: PDF (request by e-mail)

Available from the Journal's Web site.
DOI: 10.4236/ojf.2015.54035

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Abstract

Models for quantifying the growth responses of black spruce (Picea mariana (Mill) BSP.) and jack pine (Pinus banksianaLamb.) to precommercial thinning (PCT) treatments were developed. They accounted for the increased rate of stand development arising from PCT treatments through temporal adjustments to the species and site specific mean dominant height-age functions. Analytically, they utilized a relative height growth modifier consistent with observed density-dependent height repression effects. A phenotypic juvenile age-mature age correlation function was used to account for the intrinsic temporal decline in the magnitude of the PCT effect throughout the rotation. The resultant stand development patterns were in accord with theoretical and empirical expectations when the response models were integrated into algorithmic variants of structural stand density management models.

Plain Language Summary

Based on approaches deduced from previous research findings and empirical observations from density control experiments, genetic worth effect response models were developed for black spruce (Picea mariana (Mill) BSP.) and jack pine (Pinus banksiana Lamb.) plantations. The models accounted for the increased rate of stand development arising from the planting of genetically-improved stock through temporal adjustments to the species-specific site-based mean dominant height – age function. The models utilized a relative height growth modifier based on known estimates of genetic gain. The models also incorporated a phenotypic juvenile age - mature age correlation function in order to account for the intrinsic temporal decline in the magnitude of genetic worth effects throughout the rotation. Integrating the functions into algorithmic variants of structural stand density management models produced stand development patterns that were consistent with axioms of even-aged dynamics.

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