For the timber supply analysis, Forest Service staff grouped areas where similar integrated resource management practices are implemented into management zones. This approach permits analysis of the different types of forests and the range of practices in the 100 Mile House Timber Supply Area. The area in each zone was estimated from existing plans and guidelines for integrated resource management in the timber supply area. The site specific practices implemented in any one area may differ from the practices used in the analysis.
Figure 5 illustrates the area within each of the zones. The information used in the analysis to describe the integrated resource management practices in each zone is described below.
Figure 5 Area within each management zone
• Selection management* zone (142,381 hectares) — dry-belt Douglas-fir forests managed using selection management which creates forests with a wide range of ages and sizes. A portion of the timber volume is removed in the first harvest. Future harvests occur approximately every 30 years, when a volume equal to the timber growth during that period is harvested.
• Special management zone (78,392 hectares) — areas where important non-timber forest resources such as scenic viewscapes, back-country recreational opportunities, wildlife habitat, and drinking water quality (e.g., Clinton Creek community watershed) require special timber management practices. To maintain the important features in this zone, for the analysis, no more than 15 per cent of the forest is permitted to be less than three metres tall at any time. To maintain older forests, 15 per cent of the forest must be greater than 150 years old at all times.
• Integrated resource management zone (497,658 hectares) — the remaining timber harvesting land base not assigned to another zone. The objective of this zone is to integrate all resource values. For the timber supply analysis, this zone is scheduled to be harvested in at least three entries so at any given time, a maximum of 30 per cent of the zone is permitted to be under three metres tall. In order to maintain older forests within the zone, 15 per cent of the forest must be more than 150 years old at all times.
