Although the changes in the harvest forecasts are discussed here, it should be noted that Figures 2 through 5 in the original report would also change slightly. The amount of lodgepole pine shown in these land base and species summaries will be reduced.
Despite the reduction in the timber harvesting land base, the short-term harvest level is unchanged from the original analysis. Figure 1 shows the corrected base case harvest forecast, which starts at the present AAC of 1 237 000 cubic metres per year. After 30 years, the revised forecast differs from the original when the harvest level falls 2.8% from the initial level. This results in a long-term harvest level of 1 202 000 cubic metres per year. As in the original analysis, at some point beyond 200 years, the harvest level can increase but in this case, to 1 218 000 cubic metres per year.
The short-term harvest level in the 100 Mile House TSA base case is equal to the present AAC. This short-term level is primarily dependent upon the large volume of existing mature timber on the timber harvesting land base. Because the additional area removed has a lower than average timber productivity, the change to the existing amount of mature volume is relatively small.
The alternative harvest flows and the land base sensitivity analysis are shown here to demonstrate the pattern of change seen in almost all of the sensitivity analysis (Figures 1 and 2). In the original analysis, most of the harvest forecasts were at a steady level for the entire 200 year planning horizon. In the corrected analysis, most of the harvest forecasts start near the same level as in the original report. The sensitivity analysis, in general, has one of two flow patterns: (1) the harvest forecasts continue at the same level or (2) the initial level is held for 1 to 3 decades, followed by a small decrease to the long-term harvest level. Figure 2 illustrates examples of both these types of results.
The explanations contained in the original report of the major factors affecting timber supply over time are still appropriate. The reader is advised to check the original report for this information. The entire series of corrected sensitivity analysis graphs are available upon request from:
• 100 Mile Forest District, 300 S. Cariboo Highway, 100 Mile House, phone 395-7800;
• Cariboo Forest Region, 640 Borland Street, Williams Lake, phone 398-4345;
• Timber Supply Branch, first floor, 1450 Government Street, Victoria, phone 356-5947.
