As part of the provincial Timber Supply Review, the B.C. Forest Service has examined the availability of timber in the North Coast Timber Supply Area (TSA). This analysis assesses how current forest management practices affect the supply of wood available for harvesting over the next 200 years. It also examines the potential variation in timber supply stemming from uncertainties about forest growth and management actions. It is important to note that the various harvest forecasts included in this report indicate only the timber supply implications of current practices and the associated uncertainty of these implications. The forecasts are to be used for discussion purposes only; they are not intended to imply any particular allowable annual cut (AAC) recommendations.
The North Coast TSA covers a total of 1.95 million hectares, of which only about 114 000 hectares are currently considered available for timber harvesting under existing management practices. The area is dominated by hemlock and hemlock/amabilis fir stands.
The current AAC for the North Coast TSA is 600 000 cubic metres per year.
Visual quality and biodiversity objectives were not incorporated in the last analysis for the North Coast TSA. Since then, however, visual quality corridors have been established, the Khutzeymateen Valley has been given protected status for grizzly bear habitat, and proposed guidelines for ensuring biodiversity have been developed. The Inside Passage, Highway 16, and Work Channel visual quality corridors represent 8% of the area currently available for harvest. The Khutzeymateen Valley has been completely excluded from the harvestable land base. Interim harvesting guidelines meet some of the new biodiversity objectives. Other biodiversity guidelines which have not yet been implemented fully, may have impacts on the harvest forecast. This is addressed through sensitivity analysis.
Under current management assumptions, the analysis indicates that the current harvest level of 600 000 cubic metres per year can be maintained for another 6 decades, followed by a 10% decline per decade for 7 decades to a long-term harvest level of 301 000 cubic metres.
Many of the data and assumptions used in the analysis are subject to varying degrees of uncertainty. The harvest forecast is most sensitive to changes in harvest flow requirements.
Over the first 40 years, the harvest forecast is moderately affected
if existing stand yields have been overestimated and is slightly
affected if the timber harvesting land base has been overestimated.
The long-term harvest forecast is moderately affected by uncertainties
of regenerated stand volumes and the timber harvesting land base.
It is possible that the harvest level may have to begin declining
before decade 7. Overall, however, all forecasts presented
indicate that the current harvest level can be maintained for
at least a decade more without significantly reducing the future
options of resource managers.