A bioeconomic approach to assess the impact of an alien invasive insect on timber supply and harvesting: a case study with Sirex noctilio in eastern Canada

This study presents a model that assesses the potential impact of a new alien insect species, Sirex noctilio Fabricius, on pine timber supply and harvest activities in eastern Canada. We integrate the spread of S. noctilio with a broad-scale growth and harvest allocation model. Projections of pine mortality range between 25 x 106 and 115 x 106 m3 over 20 years depending on S. noctilio spread and impact assumptions. Our model suggests Ontario could experience the highest, most immediate losses (78% of the potential losses across eastern Canada), with Quebec sustaining most of the rest of the losses over the next 20 years. Potential losses of $86 to $254 million per year are simulated after 20 years. The net present value of total harvest losses after 28 years of outbreak ranges between $0.7 to $2.1 billion. Adaptation policies decrease shortterm losses by 46%-55% and delay larger harvest failures by 9-11 years. Without harvest adaptation, failures to maintain annual allowable cut levels may occur once the total area infested exceeds 15 x 106 ha. While better understanding and representing S. noctilio behaviour will involve a significant effort, there is a strong demand by policy makers for this kind of information. Cette etude presente un modele qui evalue l'impact potentiel d'une nouvelle espece d'insecte exotique, Sirex noctilio Fabricius, sur les stocks de bois de pin et les activites de recolte dans l'est du Canada. Les auteurs ont integre la propagation de S. noctilio a un modele de croissance a grande echelle et d'allocation de la recolte. Les projections concernant la mortalite du pin varient de 25 x [10.sup.6] and 115 x [10.sup.6] sur 20 ans selon les hypotheses de propagation et d'impact de S. noctilio. Leur modele indique que l'Ontario pourrait subir les pertes les plus elevees tres tot (78 % des pertes potentielles de tout l'est du Canada) et le Quebec, presque toutes les pertes a venir au cours de la periode s'etendant sur les 20 prochaines annees. Les pertes annuelles pourraient atteindre 86-254 millions $ apres 20 ans. La valeur actualisee nette des pertes totales de recolte apres 28 annees d'epidemie varie de 0,7 a 2,1 milliards $. Des strategies d'adaptation diminueraient les pertes a court terme de 46-55 % et retarderaient les pires recoltes de 9-11 ans. Sans adaptation de la recolte, l'incapacite a maintenir les niveaux de possibilite annuelle de coupe pourrait survenir lorsque la superficie totale infestee depassera 15 x [10.sup.6] ha. Bien que d'importants efforts restent a faire pour mieux comprendre et representer le comportement de S. noctilio, il y a une forte demande de la part des decideurs pour ce type d'informations. [Traduit par la Redaction]
Introduction The impact of alien invasive species on timber supply and harvest activities has been identified as one of the most immediate and potentially damaging threats to Canadian forests (Natural [...]