The following forest management practices are used in all management zones and were included in the timber supply analysis.
• Wildlife - Wildlife habitat requirements were accounted for in the timber supply analysis by requiring that 20 per cent of the timber harvesting land base has trees older than 80 years at all times and by deducting sensitive wildlife areas from the database for the analysis. Trees which provide wildlife habitat such as snags and large, old trees are retained on cutblocks.
• Basic silviculture - British Columbia laws require that harvested areas which are expected to produce timber in the future must be reforested with ecologically acceptable species within a specified time frame. The most common silvicultural practices on moist sites are to clearcut harvest, prepare the site for reforestation if needed, then plant and brush if needed. On interior dry belt Douglas-fir sites, selection management using partial cutting harvesting techniques is used.
• Harvestable ages - Minimum harvestable age is defined as the time it takes for forests to grow to harvestable size based on minimum average tree size and volume per hectare. The minimum harvestable ages used in this timber supply analysis range from 80 years for lodgepole pine to 120 years for other species.
• Green-up - To provide wildlife cover and promote watershed stability, the forest cover in a harvested area must be at least three metres tall before the adjacent timber can be harvested.
• Forest health and unsalvaged losses - Losses of timber to fire, wind damage, insects, disease and animals are minimized, and damaged timber is salvaged where and when feasible. Annual losses which are not salvaged are estimated to be 26,500 cubic metres per year based on the average losses over a number of years. The actual loss fluctuates depending on pest populations, weather and other factors.
• Timber utilization - Within areas that are clearcut, all coniferous trees that are greater than the following dimensions and that can be manufactured into lumber are considered merchantable and must be removed:
• 10 centimetre top diameter
• 15 centimetre stump diameter for lodgepole pine; 20 centimetre stump diameter for all other species
• Soil conservation - Harvesting layout follows provincial guidelines which limit the amount of land that can be occupied by roads, landings and skid trails. For the timber supply analysis, almost 12 per cent of areas with forests less than 40 years old and 1.5 per cent of areas with forests older than 40 years within the timber harvesting land base were deducted from the database to account for roads, trails and landings that have become non-productive through harvesting. To account for future roads, landings and trails, areas with forests older than 40 years were reduced by a further 8.1 per cent.
