Emulating boreal forest disturbance dynamics: Can we maintain timber supply, aboriginal land use, and woodland caribou habitat?

Abstract

The effects on timber supply incurred by implementing an ecosystem-based management strategy were evaluated in an eastern Canadian boreal forest management unit. Standard linear programming was used to test the effects of four key policy issues: (1) aim for a targeted forest age structure inspired by natural fire regime and forest dynamics (multi-cohort approach), (2) agglomerate harvest blocks in operating areas to reproduce natural disturbance patterns at the landscape scale, (3) maintain cumulated clearcutting and natural disturbance rates inside the historical range of variability, and (4) exclude from harvest areas of potential interest to aboriginal people. The targeted forest age structure was achieved with a minimum reduction of periodic timber supply, but only after 50 years. Compared to a "business-as-usual" scenario, inclusion of the first three policy issues resulted in a 3% to 11% reduction in planned timber supply and a restoration period requiring that 43% to 67% of the productive area be excluded from clearcutting activities for the next 50 years. Such results require that partial cutting not be confined to operating areas eligible for clearcutting. Further exclusion of forest areas of potential interest to aboriginal people resulted in an additional 4% to 10% decrease in planned timber supply. Validation of the coarse filters used in this study (first three policy issues) was done using habitat requirements of woodland caribou (Rangifer tarandus caribou). Almost all scenarios induced a disturbance rate likely to allow a self-sustaining woodland caribou population within 25 years.Keywords: ecosystem-based management, EBM, multi-cohort management, timber supply, boreal forest, aboriginal people, forest management scenarios, linear programming, woodland caribou FRÉSUMÉLes effets sur l'approvisionnement en matière ligneuse découlant de l'implantation d'une stratégie d'aménagement écosys-témique ont été analysés dans le cas d'une unité de la forêt boréale sous aménagement forestier dans l' est du Canada. Une programmation linéaire standard a été utilisée pour évaluer les effets de quatre principales politiques : (1) chercher à établir une structure d'âge cible de la forêt découlant du cycle naturel des feux de forêts et de la dynamique forestière (approche avec plusieurs cohortes), (2) rapprocher les blocs de coupe dans les zones exploitées afin de reproduire les patrons de perturbation naturelle à l' échelle du paysage, (3) maintenir les niveaux cumulatifs de coupe à blanc et de perturbations naturelles à l'intérieur de l'intervalle habituel de variabilité et (4) exclure les coupes d' exploitation dans les zones d'intérêt potentiel pour les peuples autochtones. La structure d'âge cible de la forêt a été atteinte suite à une réduction minime de l'approvisionnement périodique en matière ligneuse, mais seulement après 50 ans. Comparativement au scé-nario « usuel », l'inclusion des trois premières politiques a entraîné une réduction de 3% à 11% de l'approvisionnement planifié en matière ligneuse...

Viewing forests through the lens of complex systems science

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A framework to optimize the restoration and retention of large mature forest tracts in managed boreal landscapes

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A Multi-Criterion Evaluation Process for Determining Cost-Effective Harvesting Systems in Fragmented Boreal Forests

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