Potential conflicts between timber supply and habitat protection in the boreal mixedwood of Alberta, Canada: a simulation study

Abstract The boreal mixedwood forests of northern Alberta, Canada, are now being brought under management for pulpwood production. A simulation modelling exercise was undertaken to evaluate the sustainability of planned logging operations, and to explore their potential effects on wildlife habitat. Model inputs include the species composition and age structure of the forest, annual coniferous and deciduous volume requirements, and descriptions of natural stand mortality and regeneration, operational constraints, and silvicultural policies. Simple habitat suitability submodels simulate the effect of changes in forest composition on wildlife species. The model was used to explore the implications of a variety of management policies over a 73 000 km 2 forest estate in the mixedwood region. Simulations of current harvesting plans indicate that projected levels of harvesting may be sustainable, but many wildlife species will lose substantial amounts of preferred habitat. Harvesting can probably not be sustained without converting most of the region's characteristic mixed-species stands to production of single species. Alternative plans which maintain unharvested reserve areas can protect habitat (areas of mixed stands in particular) for some wildlife species, but may entail significant increases in operating costs or reductions in harvest levels. Furthermore, the reserve strategies we considered are able to maintain only between 12% and 41% of high-quality habitat for species dependent upon older stands of commercially valuable timber. Because species have different habitat requirements, increased protection for some species may exacerbate habitat losses for others.