The current forest management practices that were being approved and implemented in each zone when the timber supply analysis was initiated are briefly described below:
• Basic silviculture — British Columbia laws require areas that are harvested and expected to produce timber in the future to be reforested with ecologically acceptable species within a specified time frame (four to seven years was used in the analysis). The most common silvicultural practice is to clearcut harvest, allow for natural regeneration and/or plant, then brush and weed if needed.
• Incremental silviculture — Juvenile spacing, pruning, and commercial thinning are practised on some of the most productive sites in the Invermere Timber Supply Area.
• Protection — Forest losses due to wildfire, insects, diseases and blowdown are minimized as much as possible, and damaged timber is salvaged when feasible. Based on the best available information from the past 10 years, unsalvaged losses are estimated to be 63,597 cubic metres per year from the following sources:
• diseases (especially root rot) - 26,667 cubic metres
• insects (especially mountain pine beetle) - 18,050 cubic metres
• wildfire - 16,470 cubic metres
• other sources (including unsalvaged seed trees) - 2,410 cubic metres
• Riparian areas — Current management practices in riparian reserves mapped during the Land Use Planning process essentially preclude harvesting in order to protect water quality, fisheries and wildlife habitats, and biodiversity. Forest Practices Code requirements will soon identify riparian management zones adjacent to riparian reserves where some harvesting will be permitted.
• Wildlife/biodiversity — Eight per cent of the timber harvesting land base (18,946 hectares) has been designated for a network of forest ecosystems that connect important wildlife habitat throughout the timber supply area. This area was deducted from the timber harvesting land base for this analysis. During harvesting, current wildlife management practices include leaving a number of dead trees and larger trees, either individually or in clumps, to provide wildlife habitat.
• Harvestable ages — Minimum harvestable age is defined as the time it takes for forests to grow to harvestable size. The minimum harvest ages used in the timber supply analysis range from 70 to 160 years based on trees species and ecological information.
• Soil conservation — Harvesting layout follows provincial and regional guidelines. For the timber supply analysis, 10.5 per cent of the timber harvesting land base with forests less than 40 years old was deducted for existing roads and landings. To account for future roads and landings, 10.5 per cent of the land base with forests greater than 40 years old is deducted after these forests are harvested.
