Environmental Assessment

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AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 complete loss of thermal cover in affected areas. Alternative 1 has the greatest risk of a bark beetle attack and/or potential for a high intensity wildfire that would likely result in the loss of all or most the existing cover. Impacts to soils and vegetation from a wildfire given the relatively low quality of these sites could take multiple decades if not a century or longer. This is evident by large areas within the 1959 Aspen Flats fire, which at present remain devoid of thermal and hiding cover, 47 years later. A wildfire ignited today is more likely to be of a higher intensity due to greater fuel loadings. The more recent Skeleton, Paulina, and Evans West fires have also eliminated large areas of both tree and shrub cover, including important browse species such as bitterbrush. Local experience suggests that recovery of bitterbrush will also likely take several decades. Without planting, recovery of thermal cover to current levels would likely take multiple decades depending upon the severity and intensity of the fire. Bark beetle attack and wildfire events would be expected to have less impact in lodgepole pine stands. Similar to such events in ponderosa pine, existing thermal cover would be lost. The generally rapid regeneration characteristic of lodgepole pine and its adaptability to stand replacement fire events suggests that recovery of thermal cover in these stands would likely occur at a much faster rate than in ponderosa pine stands experiencing a similar event. Recovery could occur within 4 to 6 decades. Alternative 2 (Thermal Cover): would result in the removal of 1,727 acres of optimal and acceptable thermal cover. Almost all, 98 percent, of the reduction is associated with vegetation treatments; the remaining 2 percent with fuel reduction treatments. Thermal cover across forested habitats at project scale would decline to 690 acres or 2.6 percent of those acres. Within WRHUs, thermal cover would encompass 665 acres or 2.6 percent of the WRHU acreage. The percentage drop is greatest in the winter range only, declining to 614 acres or 2.8 percent of the acreage. Alternative 3 (Thermal Cover): would result in the removal of approximately the same number of acres as Alternative 2, 1,749 versus 1,727 acres, but results in fewer acres and lower percentages of acceptable and optimal thermal cover. Cover levels would decline to 720 acres or 2.7 percent of the forested habitat acres at project scale; 656 acres or 2.5 percent of the WHRU acres; and 615 acres or 2.8 percent of the winter range only acres. Similar to Alternative 2, almost all, 99 percent, is associated with vegetation treatments; the remaining one (1) percent with fuel reduction treatments. Alternatives 2 and 3 (Thermal Cover): Alternative 2 would result in a decline in thermal cover, including optimal and acceptable, from nine (9) percent of the acres across the entire planning area to 2.6 percent. Under Alternative 3, existing optimal thermal cover would be retained by including it in the retention portion of the unit. No optimal thermal cover would be lost under this alternative and would remain at less than 2 percent across the planning area. Within WRHUs, the decline under Alternative 2 would be from the current eight (8) percent average to 2.6 percent. There would be no change under Alternative 3 which would remain at 1.9 percent. Post-thinning canopy closures would drop to approximately 20 percent in treated stands under both alternatives. Areas targeted for vegetative treatments contain the higher quality cover, particularly thermal cover. But these acres also are at the highest risk for bark beetle infestation. Although such treatments result in an immediate short-term reduction in cover, over the longer term, cover levels, both thermal and hiding, would be expected to slowly increase. Pretreatment of understory trees, trees four (4) inches dbh and less, during post-harvest fuel reduction treatments would result in very little loss of thermal cover habitat. Cover in these tree sizes is primarily associated with foliage (i.e. hiding cover). Evidence from treatments in other similar stands suggests 3-24
AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3 that the reduction in cover assuming all trees four (4) inches dbh and smaller are removed is estimated at approximately 2.6 percent. This is attributed to the duel overlapping canopies of the understory and overstory trees (Silviculture Report, page 26). Thermal cover within the General Forest land allocation is generally not available for use by mule deer during the critical winter months because of its location at elevations above both biological and land allocation winter range. Although the decrease in thermal cover within that LRMP allocation has the greatest percentage decline under both alternatives; 90 percent (248 acres existing; 25 acres remaining) under Alternative 2 and 74 percent (248 acres existing, 64 acres remaining) under Alternative 3; the effects on wintering mule deer under normal conditions would be difficult to measure. For example, heavy snow winters when deer move off Forest, areas are inaccessible to deer and the effect would be negligible. Thermal Cover - Table 3-12 displays the effects of vegetation and fuel reduction treatments on the acres of thermal cover present in the planning area by Alternatives 2 and 3. Thermal cover acres only include optimal and acceptable cover; i.e. stands that contain canopy closures of 30 percent or greater. Table 3-12 Effects of Vegetation and Fuel Reduction Treatments on Thermal Cover for Alternatives 2 and 3 WRHU or LRMP Allocation General Forest 42 Current Thermal Cover (Alt 1) Acres of Optim al Acres of Accepta ble Alt 2 Post-Treatment Cover Reductions Optimal Acceptable Alt 3 5 243 -4 -4 Lavacicle 0 297 0 0 Mahogany 35 430 -28 0 Pine Mountain (summer range only) Pine Mountain (winter range only) 421 523 - 400 - 415 3-25 Alt 2 - 219 - 219 - 133 - 345 Alt 3 - 180 - 224 - 133 - 412 0 113 0 0 -2 -37 Potholes 5 105 -5 0 -53 -49 TePee Draw 19 334 -19 0 Totals: WRHU Winter Range Only 485 1,932 - 456 0 WR onl y; 419 gro ss - 302 - 1,2 71 - 280 - 1,2 78 Forested Habitats (Acres of Potential Thermal Cover) Alt 2 Alt 3 Post-Treatment Thermal Cover (Pct Forested Habitats / Pct desired condition 30% in WRHUs) Alt 2 Alt 3 782 782 25 / 3% 64 / 8% 1,46 5 5,91 2 5,07 7 1,12 3 558 0 7,73 4 26,5 50 25,7 68 21,8 14 1,46 5 5,91 2 5,07 7 1,12 3 5,59 2 7,73 4 26,5 50 25,7 68 21,8 14 78 / 5% 73 / 5% 304 / 5% 199 / 4% 111 / 10% 332 / 5.6% 117 / 2.3% 76 / 6.7% 52 / 1% 61 / 1% 32 /
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United States Department of Agricul
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Abstract: The Opine Planning Area i
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PROJECT LOCATION CHAPTER 1 Figure 1
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PURPOSE AND NEED CHAPTER 1 commerci
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PLANNING DIRECTION - MANAGEMENT ALL
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PLANNING DIRECTION - MANAGEMENT ALL
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OTHER PLANNING DIRECTION & STRATEGI
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OTHER PLANNING DIRECTION & STRATEGI
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ANALYSIS ISSUES CHAPTER 1 The Opine
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ANALYSIS ISSUES CHAPTER 1 overstock
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ANALYSIS ISSUES CHAPTER 1 Soils The
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ALTERNATIVE DESCRIPTIONS CHAPTER 2
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AFFECTED ENVIRONMENT & ENVIRONMENTA
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AGENCIES AND PUBLICS CONSULTED CHAP
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Environmental Assessment

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