Table 1-6 MFP Recommendations, Conflicts, and Proposed Decisions Affecting the Timber A In critical winter range, harvest in an orderly pattern and minimize the effects of cover removal. In other ranges, employ uneven-aged stand management only where prescribed for other purposes. large portion of the critical winter range will remain undisturbed by timber management activities, so normal timber management will seldom lead to adverse impact on the foraging area/cover area relationship. On the summer, spring, and fall range habitat diversity is provided by lands not subject to timber management. The small incremental advantage for big game from a more restrictive timber harvest program would not justify the economic losses. DEVELOPMENT OF THE PROPOSAL 1.2.5.2 Low Intensity Forest Management Lands Resource conflicts for the 47,840 acres of low intensity lands were essentially of the same types as those displayed in Tables 1-5 and 1-6 for high intensity lands. Inasmuch as harvest from low intensity lands is a trial program for one decade only, designed to generate specific information, none of the harvest would take place where resource conflict situations are identified. Adequate non-conflict areas are available to allow this program to proceed as planned during the decade. 1.2.5.3 Limited Forest Management Lands Lands in this category are excluded from high or low intensity management because of severe regeneration problems or fragile soils. The proposed decision is for no planned harvest from the 44,260 acres of limited management lands. Areas of conflict are similar to those of high and low intensity lands. Incidental harvest, should such be necessary, will be strictly governed by environmental assessments specific to the situation. 1.2.5.4 Minor Forest Products Sales of minor forest products--posts, poles, and particularly firewood --have been an incidental aspect of the timber management program. The demand for firewood, especially by private parties for personal use, has been increasing annually. Some of the demand is met with slash or debris from timber sales. Management of non-commercial forest forest land, primarily hardwoods, for firewood production was considered. Harvesting of firewood traditionally occurs above road cutbanks and within 200 feet of the road. The proposed decision is to manage hardwood stands for firewood on noncommercial sites with existing road access, except that no cutting would be conducted in streamside buffers and oaks would be managed primarily for wildlife. Commercial firewood sales would be made as demand developed. 1.2.6 Allowable Cut Determination The sustained yield allowable cut is determined in accordance with the objectives of the proposal and is based on the land use allocation arrived at through the Bureau planning system. Allowable cut in the proposal would be the annual harvest from high intensity lands. Volume attained through trial harvest on low intensity land, while planned and proposed for the first decade, is not predictable into the future and therefore would not be part of the proposal beyond the first decade. Within a 20-year planning horizon, the objective is to maximize sustainable yield of timber suitable for the production of lumber and plywood. For accuracy, allowable cut is computed and projected into the future on the basis of cubic feet. Since board feet Scribner is expected to remain the industry standard for the coming decade, the decadal allowable cut is converted to Scribner board foot equivalents, based on the age and size of timber expected to be included in sales during the decade. 1.2.6.1 Management Assumptions A wide range of possible management practices was considered. The practices used in the forest simulation model (described in Section 1.2.6.2) for high intensity lands are varied harvest, reforestation, and growth stimulation techniques. Prescribed harvest methods are a combination of the clearcut, two-stage shelterwood, and single tree selection systems, dependent on site suitability. Intensive planting is planned following the regeneration cut of a shelterwood regime or clearcutting. Minimum planned final harvest age would be 60 years. Approximately 1,600 acres would be converted to non-forest during the first decade due to completion of the permanent road system. It is expected to require an average of 4 years from the sale date of a clearcut or regeneration cut timber sale to establish a new stand of coniferous seedlings. The assumed regeneration period is predicated on successful plantation establishment within 1 year following a regeneration cut of the two-stage shelterwood system or clearcutting. Maximum time for removal of timber under a timber sale contract is 36 months, although the average time is less. Slash disposal and control of competing vegetation may be required prior to planting. The 4-year regeneration period is thus an estimate for use in the forest simulation model which is used to calculate the sustainable allowable cut level. This regeneration period is well within the Bureau limit of 5 years to qualify for sustained yield management. Use of genetically superior planting stock is not considered operationally feasible for the JKSYUs since sufficient supplies will not be available within the 20-year planning horizon. Genetic tree improvement is an ongoing BLM program for southwestern Oregon. When adequate supplies of genetically superior stock can be assumed the effect would be considered in allowable cut computation for the Jackson, Klamath, and Josephine SYUS. Use of herbicides for control of vegetative competition to favor growth of commercial coniferous species is proposed as part of timber stand reestablishment. Herbicides would be used for site preparation before planting on approximately 16,560 acres of high intensity lands during the first decade. Approximately 11,900 acres of established reproduction would be released from brush or grass competition by herbicide treatment during the same period. DEVELOPMENT OF THE PROPOSAL Intensive management practices enhance growth and productivity once a stand of commercial coniferous species is established. Three intensive management practices are considered suitable (for the JKSYUs) following harvest and regeneration. Precommercial thinning, commercial thinning, and fertilization are economically justified and result in net volume increases. Thinning at a 20-year interval is assumed, with precommercial thinning no earlier than age 13. Fertilization is planned and assumed in the simulation model immediately after precommercial thinning and every 10 years thereafter. Commercial thinning would be employed when stands reach commercial size--no sooner than age class 30. Each addition of an assumed practice increases the maximum potential harvest level in the computation of sustainable annual harvest. Table 1-7 shows the magnitude of potential harvest increase attributable to proposed treatments. Table 1-7 Effect of Assumed Practices on Annual Harvest Volume, High Intensity Lands 1.2.6.2 Mechanics of Computation The annual proposed allowable cut of 19.69 million cubic feet (115 MM bd. ft.) for the 258,597 acres of high intensity lands proposed for timber production was calculated with a computerized forest simulation model (SIMIX). The SIMIX model has three cutting method options: clearcut only three-stage shelterwood cut only combination clearcut and three-stage shelterwood cut Since the prescribed cutting methods for the lands in the Jackson and Klamath Sustained Yield Units are predominately clear cutting and two-stage shelterwood cutting, followed in each case by intensive planting, the net effects on stand establishment, yields and volumes per acre are very similar. Therefore, the clearcut option of the SIMIX program was utilized. The model projects the present forest 400 years into the future. Based on the management assumptions previously described and using local yield tables derived from tree form data gathered in the JKSYUS, the model determines the largest allowable cut sustainable over the 40 decade projection period. Age class distribution of forest stands, annual wood growth, wood volume, and acreage of certain treatments are also determined for each of the 40 decades. A 400-year projection is necessary to assure that the proposed allowable cut is at the highest level that can be sustained, ad infinitum, consistent with the BLM's policy for a constant or increasing flow of wood over time without any planned reduction. The projection is not to be construed as a 400-year timber management plan. As indicated in Figure 1-4, the most critical elements that influence the magnitude of the proposed allowable cut are total wood volume and annual wood growth, present and future. In the JKSYUs the proposed allowable cut is approximately four times the present current annual growth. This difference is primarily due to the preponderance of overmature stands in the JKSYUs, which are growing at low rates (or not at all) as a result of high natural wood loss caused by insects, disease, and tree mortality. As older stands are harvested and replaced with vigorous young-growth stands, two things would occur: The total wood volume would be reduced as existing overmature timber was removed, but total annual growth would increase over time. By the year 2038, growth would exceed the allowable cut, indicating that the cut theoretically could then be increased if all other things were to remain constant. It is approximately at this time that a forest comprised of an equal distribution of age class acreages, ranging from recently established stands through stands 70 years old, would be attained. From then on, total volume and annual growth would be in perpetual equilibrium and therefore annual cut would equal annual growth. |