A silvicultural decision-support algorithm for density regulation within peatland black spruce stands

Abstract

Determining the optimal density management regime for a given stand-level objective is a complex proposition faced by forest managers. Although decision-making for volumetric yield objectives has been greatly simplified with the advent of stand density management models, addressing new objectives arising from the paradigm shift towards the production of enhanced end-products and a broader array of ecosystem services remains a challenge when managing commercially-important boreal species. Consequently, the objectives of this study were to (1) develop an integrated modular-based structural stand density management model (SSDMM) and a corresponding algorithmic analogue for peatland black spruce ( Picea mariana (Mill.) BSP.) stands, and (2) given (1), demonstrate its utility as a crop planning tool within the context of silvicultural decision-making. The SSDMM was developed using 495 tree-list measurements obtained from 137 permanent and temporary sample plots, remeasurement data from 30 Nelder plots, and published relationships derived from diameter distribution and height–diameter modelling studies, density control experiments and sawmill simulation analyses. The resultant algorithm enabled the evaluation of the rotational consequences of competing density management regimes in terms of overall productivity, log-product distributions, biomass production and carbon yields, recoverable end-products and their associated monetary value, economic efficiency, duration of optimal site occupancy, structural stability, and wood fibre attributes. The utility of employing the model as a generic modelling platform for structural yield prediction for other species is also discussed.