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TAHOE NATIONAL FOREST, AMERICAN RIVER RANGER DISTRICT
BIG HOPE PROJECT
FIRE & FUELS SPECIALIST REPORT
Introduction In August 2013, the American Fire burned approximately 27,400 acres, 22,500 acres on the American River Ranger District of the Tahoe National Forest and 4,900 acres on adjacent private lands. The fire burned roughly 38 percent of the North Fork of the Middle Fork of the American River Watershed, with portions of the Black, Secret, Manila and Screwauger Canyon watersheds experiencing the highest vegetative burn severity resulting in large areas of standing dead trees. The Big Hope Project is being proposed as a management response to the American Fire. The proposed management actions are designed to recover the economic value of fire-killed trees, reduce public safety hazards along portions of roads and trails and at trailheads and recreation sites, reduce the danger and difficulty of suppressing future wildfires, and re-establish forested conditions and habitats in burned forest stands.
Purpose and Scope The purpose of this report is to analyze and compare predicted current and future wildfire characteristics from the proposed alternatives (action and no action) addressed in the Big Hope Project Environmental Analysis (EA) on the American River Ranger District, Tahoe National Forest, Placer County, California. In particular, this analysis will focus on the following effects:
• The direct effect of the proposed action and no action alternatives on existing and future wildfire potential characteristics within the treated areas.
• The indirect effect of the proposed action and no action alternatives on existing and future wildfire characteristics and probable control options adjacent to the treated areas.
• The cumulative effect of the proposed action and no action alternatives on existing and future wildfire potential characteristics within the Big Hope Analysis Area.
• The direct, indirect and cumulative effects of the proposed action and no action alternatives on air quality.
Background Before the American fire, the Big Hope Project area was comprised of even-aged mixed conifer plantations, dense white fir stands and scattered uneven aged sierran mixed conifer stands. There were no recorded instances of wildfire in the majority of the fire area since 1908, the earliest reliable date available. Elevations in the fire area range from 2240 feet above sea level along the North Fork of the Middle Fork of the American River to 7080 feet at Duncan Peak. Slopes range from near flat to near vertical. Prior to European settlement, the average natural fire return interval for the Big Hope area ranged from 11 to 26 years with more than 90% of the landscape burning less than 16 years (Safford et. al., 2011). The landscape has been heavily influenced over the last 100 years by mining, grazing, logging, and fire suppression activities. At the stand level, the combination of these activities had
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created overstocked stands with high accumulations of surface fuels, often under an unbroken “fuel ladder” of understory vegetation extending to the forest canopy. Illustration 1 below shows the 2013 American Fire, with historic fire areas shown from 1908. Illustration 1. American River Ranger District Fire History
Post-fire conditions were assessed through remote sensing and field observations. The burn severity of the fire was mapped utilizing The Rapid Assessment of Vegetation Condition after Wildfire (RAVG) process. The RAVG products are based on a seven-class basal area loss layer modeled from the relative differenced Normalized Burn Ratio surface. In the context of RAVG analysis, basal area loss measures the percent change in basal area or tree cover (relative number of live trees on the site) from the pre-fire condition. Basal area loss is expressed as four classes of percent change in tree cover and is measured in square feet. Basal area loss does not describe a permanent loss of basal area within a forest, but simply describes the amount of change in the live tree cover immediately (30 days after) wildfire containment.
The seven-class layer is grouped into four classes for the Geographic Information Systems (GIS) overlay analysis and subsequent RAVG table and map generation. The data tables and maps are created using existing vegetation maps overlain with basal area loss results. Existing Vegetation Types (EVTs) are grouped and used for the GIS overlay analysis.
The seven-class basal area loss layer contains the following classes:
• Class 1 = 0% basal area (BA) loss
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• Class 2 = 0% - less than 10% BA loss • Class 3 = 10% - less than 25% BA loss • Class 4 = 25% - less than 50% BA loss • Class 5 = 50% - less than 75% BA loss • Class 6 = 75% - less than 90% BA loss • Class 7 = 90% or greater BA loss
The seven-class basal area loss layer is grouped into the following four classes for the GIS overlay analysis:
• Class 1 = 0% - less than 25% BA loss • Class 2 = 25% - less than 50% BA loss • Class 3 = 50% - less than 75% BA loss • Class 4 = 75% - 100% BA loss
In the low severity burn areas (GIS overlay classes 1 and 2), fifty to ninety percent of existing surface fuels were consumed, with most trees less than ten inches diameter at breast height (dbh) killed. Most trees over ten inches dbh have varying degrees of scorch, but initially survived. In the moderate severity burn areas (GIS overlay classes 2 and 3), pockets of trees in all size classes are completely killed. In the high severity Burn areas (GIS overlay classes 3 and 4), up to one hundred percent of the trees are dead, with most foliage completely consumed. Surface fuels and associated ground cover in moderate and high severity burn areas has been greatly reduced, if not entirely eliminated. Illustration 2 below shows the RAVG burn severity for the American Fire. The areas of highest fire severity were not confined to specific elevations, slopes, or aspects. Overall, fire severity was a mix of low and moderate severity with several large patches of high burn severity.
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llustration 2. RAVG burn severity for the American Fire
Table 1 quantifies the Fire Severity within the Big Hope Project Area and the total American Fire Area.
Table 1.Basal Area Mortality from the American Fire
Fire Severity (BA Mortality)
Total 0- 50% 50 - 75% > 75% Project Area (Acres/Percent)
4,354 Acres 43%
923 Acres 9%
4,811 Acres 48%
10,088 Acres*
Total American Fire Area (Acres/Percent)
16,879 Acres 62%
2,325 Acres 8%
8,222 Acres 30%
27,436 Acres
*The total acreage of the burn severity categories within Big Hope treatment areas is less than the total acreage of proposed treatment area. 477 acres of the treatment unit area fall outside of the RAVG burn severity GIS data. Guiding Regulations and Policies The Big Hope Fire Recovery Project is designed to fulfill the management direction specified in the 1990 Tahoe National Forest Land Resource Management Plan (LRMP) as amended by the 2004 Sierra Nevada Forest Plan Amendment (SNFPA). Proposed management activities are designed to comply with the standards and guidelines as described in the LRMP and SNFPA. The American Fire area falls within six Management Areas (MAs) described in the LRMP:
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Management Area 84 (Humbug-Sailor). This MA is located on the gently to moderately sloped uplands overlooking the North Fork of the American River canyon. Of the approximately 215 acres of the fire area that fall within this MA, 50 acres of restoration treatments including tree planting, salvage logging and roadside hazard tree removal are proposed. The major resource emphasis for this MA is vegetation management. Management Area 90 (Divide). This MA encompasses the Foresthill Divide Road from the Chicken Hawk area to the junction of the Soda Springs Road. Of the approximately 2080 acres of the fire area that fall within this MA, 1100 acres of restoration treatments including tree planting, salvage logging and roadside hazard tree removal are proposed. Roadside visual quality and fuel break construction and maintenance are major resource management emphases for this MA. Management Area 91 (Sunflower). This MA is encompassed by Sunflower Hill on the north, MA 89 (French) on the south and east, and Duncan Peak on the west. Of the approximately 1635 acres of the fire area that fall within this MA, 185 acres of restoration treatments, primarily roadside hazard tree removal are proposed. Timber and range management are major resource management emphases for this portion of MA 91. Management Area 92 (Peavine). Approximately 18’600 acres, 68 percent of the American fire area falls within this MA. Approximately 8100 acres of restoration treatments including tree planting, salvage logging and roadside hazard tree removal are proposed in this MA. Timber and range management are major resource management emphases for MA 92. Management Area 98 (Eldorado). This MA is located primarily in the Middle Fork of the American River watershed. Of the approximately 18600 acres of the fire area that fall within this MA, 1060 acres of restoration treatments including tree planting, salvage logging and roadside hazard tree removal are proposed. Timber and range management are major resource management emphases for this portion of MA 98 Management Area 99 (Mosquito). This MA contains the roadside corridor (visual foreground) of the Mosquito Ridge Road from the western forest boundary to Red Star Ridge. Of the approximately 110 acres of the fire area that fall within this MA, 70 acres roadside hazard tree removal are proposed Roadside visual quality and fuel break construction and maintenance are major resource management emphases. Management Area 104 (Grouse Falls). This MA is located on Grouse Creek, a mile above its confluence with the North Fork of the Middle Fork American River, just outside the American Fire perimeter. The falls are in a steep, rugged canyon, reached only by a primitive trail. Because of its location and the steep canyons of Grouse Creek and North Fork of the Middle Fork of the American River, the area receives limited recreation use. No restoration activities are planned for this MA.
Management Intent and Objectives The 2004 SNFPA Appendix A, Part D directs the forests to “determine the need for ecosystem restoration projects following large, catastrophic disturbance events” (including wildfire) and that “salvage harvest of dead and dying trees may be conducted to recover the economic value of this material and to support objectives for reducing hazardous fuels, improving forest health, reintroducing fire, and/or re-establishing forested conditions.”
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Broad-scale forest plan goals include:
• Treating fuels in a manner that accelerates dispersal of coarse woody debris compared to untreated areas, thereby contributing to more effective fire management.
• Treating hazardous fuels in a cost-efficient manner to maximize program effectiveness.
• Actively restoring fire-adapted ecosystems by accelerating development of mature forest habitat.
• Strategically placing treatments across landscapes to interrupt potential fire spread and facilitate wildfire management tactics and objectives.
Overall Big Hope Project objectives for fire and fuels management include:
• Reducing volume of standing dead timber, thereby reducing the danger and difficulty of managing future wildfires.
• Reducing snag hazards on roads, trails and other areas that typically provide access, egress and staging areas for fire suppression, fuels management, and other forest operations and projects.
• Reestablishing the fuel characteristics of resilient, fire-adapted forests. Intensity Criteria Pertaining to Resource The effects of treatment on fuels and potential fire behavior are evaluated using the following measurement indicators. Surface Fuel Load: The predicted surface fuel loads (tons per acre), as computed by the Fire and Fuels Extension to the Forest Vegetation Simulator (FFE/FVS) are reported under the direct and indirect effects for each alternative. FFE/FVS is a model used to summarize current stand conditions, predict future stand conditions under various management alternatives, and update inventory statistics (Dixon, 2002). Fuel loads are reported in tons per acre for the following fuel classes:
• Forest duff. Forest duff is the fermentation and humus layers of the forest floor. It does not include the freshly cast material in the litter layer. The top of the duff is where needles, leaves, and other castoff vegetative material have noticeably begun to decompose. Individual particles usually will be bound by fungal mycelium. When moss is present, the top of the duff is just below the green portion of the moss. The bottom of the duff is mineral soil.
• Forest Litter. Forest Litter is the surface layer of the forest floor and consists of freshly fallen leaves, needles, twigs, bark, and fruits (Brown 1974).
• Downed woody material from one to three inches in diameter. • Downed woody material from three to six inches in diameter. • Downed woody material from six to twelve inches in diameter. • Downed woody material greater than twelve inches in diameter. • Herbs (grasses, forbs, etc.) and shrubs. • Standing trees greater than three inches dbh, both live trees and dead snags
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The volume and condition of surface fuels is critical in determining fire potential. Fine (less than three inches in diameter) dead surface fuels respond to ambient environmental conditions and determine the rate of spread and intensity at the fire front. Larger dead surface fuels respond more slowly to environmental conditions, but may extend fire residence times and be more difficult to extinguish. Live surface fuels typically become more susceptible to ignition as the dry season progresses. In the post-fire environment, standing dead trees greater than three inches dbh present considerable challenges to fire management resources. These snags are not only susceptible to ignition from wildfires, but are more likely to fall suddenly the longer they stand. Fire suppression forces often cannot safely attack fires burning in areas of high snag density, regardless of fire intensity or rate of spread. The volume of surface fuels remaining after the American Fire vary with fire intensity, but begin to rise quickly as new vegetation colonizes the burned area, and fire killed and damaged vegetation begins to decompose and fall to the forest floor. The volume of standing dead trees peaks within a year of the fire event, then gradually declines as the trees fall. Reduced surface fuel volumes and lower volumes of standing dead snags greater than three inches dbh under the proposed action represent desired conditions for fire and fuels management. Flame Length: Flame length (measured in feet) is influenced by fuel type, fuel arrangement, fuel moisture, and weather conditions. Fuel type and fire intensity in turn influence fire line production rates by different suppression resources. Increased flame lengths indicate an increase in fire intensity and the likelihood of high mortality in naturally regenerated, newly planted and fire-survived stands. Predicted flame lengths that do not significantly increase under the proposed action represent acceptable conditions for fire and fuels management. Tools Used to Predict Impacts Effects of the proposed alternative on fuels and future wild fire characteristics are compared to the no-action alternative. FFE/FVS was used predict surface flame lengths, surface fuel loads, and standing dead timber greater than three inches dbh before and after the proposed treatments. Forest stand data collected before the fire was “burned” in a simulated wildfire under severe and moderate fire weather conditions. These outputs were then compared to post-fire field observations for representative accuracy. The model was used to quantify existing conditions and to predict the effects of alternative treatments on fuel loads and high intensity fire potential. Modeled results are used to highlight the relative differences resultant of the proposed action against the no action alternative. Assumptions Made:
• Baseline stand data is representative of conditions in the pre-fire Big Hope Project area.
• Model outputs predict existing and future potential wildfire effects under severe and moderate fire weather and fuel moisture conditions within the treatment areas. While rare, severe weather conditions occur annually during the summer fire season. Historically, ignitions occurring under severe weather and fuel moisture conditions exceed initial attack suppression capabilities and become large, high severity wildfires.
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Alternative 1, the Proposed Action (see Chapter 2 of the EA for a full description of the proposed action) Ground-based harvesting and follow-up fuels treatments
• Fire killed trees greater than twelve inches dbh would be considered for commercial timber harvest.
• Non-merchantable fire killed trees may be felled and left in place, or left standing. • In the majority of the treated stands activity generated fuels will be lopped and
scattered to a depth not to exceed 18 inches (particularly in areas of low to nonexistent surface fuels) as a follow-up fuels treatment and site preparation for tree planting.
• Mechanical treatments may be used to disperse activity fuels and prepare sites for tree planting. Mechanical treatments may include masticating, or machine piling and burning activity and residual fuels.
• Tree planting activities would include site preparation (as needed), variable spacing, cluster planting, establishment of founder stands, or natural regeneration (where appropriate), and follow up release treatments.
Cable harvesting and follow-up fuels treatments
• Fire killed trees greater than twelve inches dbh would be considered for commercial timber harvest.
• Non-merchantable fire killed trees may be felled and left in place or left standing. • In the majority of the treated stands activity generated fuels will be lopped and
scattered to a depth not to exceed 18 inches (particularly in areas of low to nonexistent surface fuels) as a follow-up fuels treatment and site preparation for tree planting.
• Hand treatments may be used to disperse activity fuels and prepare sites for tree planting. Hand treatments may include lopping and scattering to a depth not to exceed 18 inches or piling and burning activity and residual fuels.
• Tree planting operations will include site preparation (as needed), variable spacing, cluster planting, establishment of founder stands, or natural regeneration (where appropriate), and follow up release treatments.
Roadside hazard tree removal
• Hazard trees would be identified using the Hazard Tree Guidelines for Forest Service Facilities and Roads in the Pacific Southwest Region (Angwin et al. 2012).
• Merchantable fire-killed trees would be felled and removed. • Non-merchantable fire killed trees may be felled and left in place, or left standing.
(The analysis of direct and indirect effects assesses standing snags greater than 3 inches dbh (in tons per acre).)
• In the majority of the treated areas activity generated fuels will be lopped and scattered to a depth not to exceed 18 inches (particularly in areas of low to nonexistent surface fuels) as a follow-up fuels treatment and site preparation for tree planting.
• Mechanical treatments within the hazard tree removal areas may be used to disperse activity fuels and prepare sites for tree planting. Mechanical treatments may include masticating, or machine piling and burning activity and residual fuels.
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• Tree planting operations will include site preparation (as needed), variable spacing, cluster planting, establishment of founder stands, or natural regeneration (where appropriate), and follow up release treatments.
Tree planting in high severity burn areas
• Tree planting will generally occur in identified areas of moderately high to very high fire severity, as well as all salvage harvest areas and identified areas of roadside hazard tree removal.
• Tree planting operations will include site preparation (as needed), variable spacing, cluster planting, establishment of founder stands, or natural regeneration (where appropriate), and follow up release treatments.
Alternative 2, No Action
• No treatments would occur in any areas.
DIRECT, INDIRECT AND CUMULATIVE EFFECTS ANALYSIS
Alternative 1, Proposed Action American Fire area includes approximately 22,500 acres of national forest land and 5,000 acres of private land. Within this area, approximately 3,443 acres (thirteen percent) would be salvage logged. 5,519 acres (fifteen percent) would host roadside hazard tree removal operations. A total of 7,295 acres (twenty seven percent) would be reforested. Under the proposed action, approximately thirty eight percent of the entire fire area would host fire restoration treatments (Table 2.) Table 2. Summary of the Big Hope Project proposed action treatment activities
Activities Acres Treated Total Salvage Harvest1 3,443 Tractor Salvage Harvest 3,008 Aerial Salvage Harvest 435 Total Roadside Hazard Tree Removal2 5,519 Total Tree Planting3 7,295 Tree Planting Areas With Mechanical Site Preparation and Release
• Mastication on 2,476 acres • Mechanical Piling on 1,148 acres
3,624
Tree Planting Areas With Hand Site Preparation and Release 445 Tree Planting Areas With Mechanical Release Only (no site preparation) 1,332 Tree Planting Areas With Hand Release Only (no site preparation) 1,894 Total Footprint of Treatment Areas4 10,566
1 Roadside hazard tree removal overlaps 2,248 acres of the identified salvage harvest and planting areas. 2 Calculation assumes 200 feet along both sides of road segments; however, hazard tree frequencies and distances are extremely variable. 3The tree planting total includes the 3,443 acres planned for planting within salvage harvest areas.
1 Roadside hazard tree removal overlaps 2,248 acres of the identified salvage harvest and planting areas. 2 Calculation assumes 200 feet along both sides of road segments; however, hazard tree frequencies and distances are extremely variable. 3 The tree planting total includes the 3,443 acres planned for planting within salvage harvest areas. 4 The total “footprint” acreage figure does not include overlap with other treatment areas. It represents the actual landscape footprint.
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4 The total “footprint” acreage figure does not include overlap with other treatment areas. It represents the actual landscape footprint.
Direct and Indirect Effects Analysis Salvage Harvest and Roadside Hazard Tree Removal Treatment in these areas is assumed to consist of removal of merchantable fire-killed trees. Fire-killed trees are burned trees that either (1) have no green needles or (2) meet the criteria of a 0.7 Probability of Mortality (Pm) in the Marking Guidelines for Fire-Injured Trees in California, Report # RO-11-01 (Smith and Cluck 2011). A major criterion used would be evidence of significant wood boring and bark beetle activity as detailed in (Smith and Cluck 2011). Commercial-sized trees being considered for this project are a minimum of 12 inches dbh, however, the minimum diameter could increase during project implementation to ensure harvest of sound, utilizable timber. Non-commercial trees may be felled and left on site to reduce public safety hazards along roads, trails, and recreation sites, to reduce overhead hazards of future tree planting efforts or to provide soil stability. Non-commercial trees that remain standing would eventually fall and add to surface fuel loadings on site. Where feasible and appropriate, activity generated fuels (logging slash, etc.) would be removed by burning or biomass utilization. Activity generated fuels not removed would be lopped and scattered to a depth not to exceed 18 inches or masticated (particularly in areas of low to nonexistent surface fuels) as a follow-up fuels treatment and site preparation for tree planting. Hazard trees would be felled along roads and recreation trails, as well as at trailheads and other recreation sites within the Big Hope Project Area. Hazard trees with commercial value (generally greater than 10 inches dbh depending on timing of removal) would be commercially harvested. The limbs and tops of cut trees would generally be lopped and scattered to a depth not to exceed 18 inches. Non-merchantable hazard trees could also be felled and left on site. Chart Series 1 illustrates expected results from salvage harvest and hazard tree removal in areas of high burn severity. Chart 1.1 Average Surface Fuels in High Severity Burned Stands
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Chart 1.1 illustrates the predicted trend in surface fuel loads under the proposed action (“12 in min dbh Cut”) and no action (“Existing Condition”) alternatives. Prior to the fire there was an average of approximately 30 tons per acre of total surface fuels. After the fire, there is approximately 10 tons per acre. If no action is taken, average surface fuels would increase to approximately 45 tons per acre within 20 years. Under the action alternative surface fuels consumed in the 2013 fire are replaced with material brought to the ground with the salvage harvest. Because the majority of large snags would be removed and not allowed to remain in the stand, fuel loadings are expected to remain relatively constant within the treatment areas for the next 20 years. No activity fuels are removed in this illustration, any activity fuels removed by site preparation or plantation release activities could further lower fuel loads under the proposed action. Chart 1.2 Average Number of Snags Greater Than 3” dbh in High Severity Stands
Chart 1.2 illustrates the predicted volume of standing snags greater than 3 inches dbh under the proposed (“12 in min dbh Cut”) and no action (“Existing Condition”) alternatives. While not completely eliminated, the hazard to future firefighters, forest workers and forest visitors
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Year
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Existing Condition
12 in min dbh Cut
0.0010.0020.0030.0040.0050.0060.00
Tons per Acre
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Existing Condition
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from falling snags in the treatment areas are reduced from approximately fifty tons per acre under the no action alternative, to under ten tons per acre under the proposed action. Chart 1.3 Average Flame Lengths in High Severity Stands
Chart 1.3 illustrates predicted future flame lengths under the proposed (“12 in min dbh Cut”) and no action (“Existing Conditions”) alternatives during high and moderate fire danger conditions in the fire areas that experienced high severity in the American Fire. In both alternatives, predicted flame lengths increase to over ten feet under high fire danger conditions, and remain under four feet (generally recognized to be the limit of control for direct attack fire suppression methods (Deeming et al. 1977)) under moderate fire danger conditions (which is approximately ninety percent of overall fire conditions, based on fire weather records from the last ten years). This increase is primarily due to the increased ratio of fine dead surface fuels to larger and live fuels after the fire, and the predicted higher mid-flame windspeeds due to reduced vegetation in the burned area. While the predicted flame lengths are initially somewhat higher under the proposed action, they become statistically equal over time. No activity fuels are removed in this illustration, any fuels removed or dispersed by site preparation or plantation release activities could further reduce flame lengths under the proposed action. Chart Series 2 illustrates expected results from salvage harvest and hazard tree removal in areas of low to moderate fire severity. Chart 2.1 Average Surface Fuels in Low and Moderate Severity Burned Stands
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2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032
FL (feet)
Year
Flame Length High Severity Stands Average
Existing Conditions/HighFire Danger
Proposed Action 12 mindbh Cut/High FireDanger
ExistingConditions/ModerateFire Danger
Proposed Action 12 mindbh Cut/Moderate FireDanger
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Chart 2.1 illustrates the predicted trend in surface fuel loads under the proposed (“12 in min dbh Cut”) and no action (“Existing Condition”) alternatives. Prior to the fire there was an average of approximately 30 tons per acre of total surface fuels. After the fire, there is approximately 10 tons per acre. If no action is taken, average surface fuels would increase to approximately 20 tons per acre within 20 years. The similarity in results for both alternatives reflected in this chart illustrates the relatively low number of trees greater than 12 inches dbh killed by the fire in stands with low to moderate vegetation burn severity, thus the lower volume of salvage logging activity generated fuels. Surface fuels brought to the ground with the salvage harvest are initially somewhat higher than those accumulating under the no action alternative, but become statistically equal over time. The surface fuel load increases at a virtually equal rate under both alternatives. No activity fuels are removed in this illustration, any fuels removed by site preparation or plantation release activities could further lower fuel loads under the proposed action. Chart 2.2 Average Number of Snags Greater Than 3” dbh in Low and Moderate Severity Stands
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2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032
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ExistingCondition
12 in mindbh cut
0.002.004.006.008.00
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Existing Condition
12 in min dbh cut
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Chart 2.2 illustrates the predicted volume of standing snags greater than 3 inches dbh under the proposed (“12 in min dbh Cut”) and no action (“Existing Condition”) alternatives. While not completely eliminated, the hazard to future firefighters, forest workers and forest visitors from falling snags in the project area are reduced from approximately six tons per acre under the no action alternative, to under two tons per acre under the proposed action. Chart 2.3 Average Flame Lengths in Low and Moderate Severity Stands
Chart 2.3 illustrates predicted future flame lengths under the proposed (“12 in min dbh Cut”) and no action (“Existing Condition”) alternatives. In the low to moderate burn severity stands, predicted flame lengths remain under four feet in both alternatives and under moderate and high fire danger conditions for twenty years. Predicted flame lengths are statistically equal. No activity fuels are removed in this illustration, any fuels removed or dispersed by site preparation or plantation release activities could further reduce flame lengths under the proposed action. Plating Trees in Burned Areas Areas of national forest lands that experienced moderate to high vegetation burn severity effects would be hand planted with 1 and 2-year-old mixed conifer seedlings. Planting strategies designed meet desired future conditions may include variable spacing, cluster planting, and establishment of founder stands. Surviving and colonizing hardwoods would be retained and encouraged. Site preparation and future release activities would be determined by planting area conditions (e.g., slopes, soils, quantity of downed trees, quantity of small diameter snags, re-sprouted vegetation, etc.). Site preparation and future release are done utilizing mechanized equipment or by hand, based on site conditions. Fire killed and/or resprouting vegetation within planting areas (standing and/or on the ground) may be lopped and scattered, masticated, chipped, or piled and burned to provide a safe, operable planting area and to benefit future fire and fuels management objectives (see explanation of tree planting strategy in Chapter 2 of the EA). To release the planted seedlings, competing vegetation may be similarly treated within one, three, or five years after planting. The effects of reforestation on future wildfire behavior cannot be accurately modeled for the Big Hope Project due to the highly variable nature of existing fuel conditions, and the
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Existing Conditions/ModerateFire danger
Proposed Action 12 min dbhCut/Moderate fire Danger
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different locations, degrees, and techniques of site preparation, planting, and plantation release activities. Consideration of the purpose, need and long term objectives of planting trees in the Big Hope Project support the following basic conclusions:
• Proposed planting areas generally burned with moderate to high severity in the American Fire. Surface fuels are greatly reduced, if not completely consumed. This reduction of fuels reduces the likelihood, size, and severity potential of future wildfires until these surface fuels regenerate.
• Site preparation and plantation release activity generated fuels that are not removed from the site (e.g. mastication) would be dispersed to the surface, accelerating decomposition and reducing heavy concentrations of dead fuel. Depending on existing surface fuel conditions (quantities), this management strategy may increase the risk of plantation loss to wildfire until the activity fuels decompose.
• Site preparation and plantation release activities that remove fuel (e.g., burning, biomass utilization) would maintain low surface fuel loads and prevent the development of ladder fuels, significantly decreasing the probability of high intensity fire for ten or more years into the future.
Summary of Direct and Indirect Effects for Alternative 1 Significant reduction to near total elimination of surface and small understory (ladder) fuels is a persistent characteristic of the areas that burned with moderate and high severity effects within the Project Area. This change in fuel loading and composition is expected to reduce wildfire intensities and rates of spread for several years. However, high snag densities and a complex arrangement of fallen trees, broken tops and branches intermixed and suspended within an increasingly heavy shrub component would eventually limit the ability of firefighters to safely and effectively control future wildfires, particularly in strategic locations that could be used for future fire suppression actions. Salvage logging and planting trees in moderate and high fire severity fire areas would generate some surface fuel, but the important factors in future fire behavior would be the naturally sprouting vegetation, the planted trees, and the wildfire-reduced volume of fine dead surface fuels. Reestablishment of a mixed conifer forest through planting would result in a wildfire risk (principally to the planted trees) in or immediately adjacent to these plantations. The potential for higher fire severity increases approximately five years after planting. Without plantation management, predicted fire severity increases until the trees overtop competing shrubs and begin to self-prune. Salvage logging and planting trees in low fire severity fire areas may generate concentrations of surface fuel, principally where the trees are felled. These “pockets” would produce a temporary and localized increase future fire severity potential as the activity fuels disperse and decompose. Since the majority of the dominant and co dominant trees in these areas survived the fire, naturally sprouting vegetation and associated development of surface and ladder fuels is expected to be less than moderate and high severity stands. The American fire reduced mean surface fuel loads by over sixty percent even in low severity burn areas. Consequently, the areas of elevated fire severity potential (from harvest generated slash) are relatively small, isolated, and surrounded by large areas of drastically reduced fuels.
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The primary adverse effect of the proposed action is the risk to reforested areas as surface fuels accumulate and the planted trees grow. While fire severity levels would remain reduced throughout the burn area, future fires could ruin tree planting efforts under high fire danger conditions. Established plantation management practices (Site preparation, variable stocking, thinning, pruning, weeding, brush removal, etc.) greatly reduce the possibility of a plantation killing wildfire. Mastication of competitive vegetation in or near plantations would contribute positively to tree health and vigor, but would not necessarily reduce future fire danger due to fuels remaining on site. Removal of on-site fuels through burning or biomass utilization is most effective in reducing the possibility of a plantation killing wildfire. The American Fire dramatically reduced surface fine fuel loads, old deep duff and litter layers, and ladder fuel continuity across a wide area. This overall reduction in potential severe fire behavior is expected to persist for years. The proposed action would temporarily contribute to the surface fuel load, but not enough to significantly increase fire danger. As they grow and without future management, plantations could be vulnerable to wildfires under high fire danger conditions. Cumulative Effects for Alternative 1 In order to understand the contribution of past actions to the cumulative effects of the proposed action and alternatives, this analysis relies on current environmental conditions as a proxy for the impacts of past actions. This is because existing conditions reflect the aggregate impact of all prior human actions and natural events that have affected the environment and might contribute to cumulative effects. This cumulative effects analysis does not attempt to quantify the effects of past human actions by adding up all prior actions on an action-by-action basis. There are several reasons for not taking this approach. First, a catalog and analysis of all past actions would be impractical to compile and unduly costly to obtain. Current conditions have been impacted by innumerable actions over the last century (and beyond), and trying to isolate the individual actions that continue to have residual impacts would be nearly impossible. Second, providing the details of past actions on an individual basis would not be useful to predict the cumulative effects of the proposed action or alternatives. In fact, focusing on individual actions would be less accurate than looking at existing conditions, because there is limited information on the environmental impacts of individual past actions, and one cannot reasonably identify each and every action over the last century that has contributed to current conditions. Additionally, focusing on the impacts of past human actions risks ignoring the important residual effects of past natural events, which may contribute to cumulative effects as much as human actions. By looking at current conditions, we are sure to capture all the residual effects of past human actions and natural events, regardless of which particular action or event contributed those effects. Third, public scoping for this project did not identify any public interest or need for detailed information on individual past actions. Finally, the Council on Environmental Quality issued an interpretive memorandum on June 24, 2005 regarding analysis of past actions, which states, “agencies can conduct an adequate cumulative effects analysis by focusing on the current aggregate effects of past actions without delving into the historical details of individual past actions. The cumulative effects boundaries considered in this analysis begin with the proposed treatment areas themselves. Changes in fire behavior potential are most readily evident and easily modeled within the treated areas. FFE/FVS predictions of future fuel characteristics
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and surface flame length was modeled for twenty years after the 2013 fire and salvage logging operations. After twenty years successfully reforested areas are expected to begin overtopping resprouting shrubs. In other areas, brush and shrubs will become the dominant vegetation for the foreseeable future. The proposed treatments are also expected to positively influence wildfire behavior outside of the treated areas. (Finney 1999) suggests that fire spread rates can be reduced, even outside of treated areas, if a fire is forced to flank areas where fuels have been reduced or otherwise modified. The treated areas, particularly those with reduced fuels from site preparation and/or plantation release activities would slow the spread and reduce the intensity of oncoming fires, thereby reducing severe fire effects in both treated and untreated areas. There are also cumulative effects associated with the American fire area as a whole. Typically, wildfire “scars” support varying but consistently reduced degrees of fire intensity many years after they occur (Collins et al 2008). As a result of the fuels consumed in the 2013 fire, it is likely wildfires within the American fire perimeter will be smaller, less destructive and easier to control for ten or more years to come, depending on the fuel conditions at the point of ignition. Future fires will likely exhibit lower intensity and rates of spread upon entry into the American area for at least the next five to ten years. Expected effects of the Big Hope proposed actions, together with cumulative effect of the fire itself are less intense, more easily and economically managed future wildfires within the entire Big Hope analysis area. Suppression and suppression repair actions taken during and immediately after the American Fire affected the environment. They included aerial drops of water and fire retardant chemicals, burning and chipping of fuels along control lines, construction of containment lines by heavy equipment and hand crews, live-tree and snag falling, and construction of personnel and equipment staging areas, helicopter landing areas, and cleared areas to provide for firefighter safety. Fire suppression repair activities included returning roads, containment lines, staging areas, helicopter landing areas, safety zones to as close to pre-incident conditions as possible, applying erosion control measures to containment lines; removing debris resultant of suppression actions from stream channels, and covering exposed soil with natural vegetation to protect soil structure. These activities alter the environment by removing vegetation, compacting soils or introducing or spreading invasive species. Such activities generally caused localized effects, but are not considered significant relative to fuels, fire, and air quality. Burned Area Emergency Rehabilitation (BAER) activities were taken to mitigate effects of the fire which might cause imminent danger to life, property, or natural resources. Rehabilitation efforts focused on restoration and improvement of drainage functions, mastication of dead vegetative material to reestablish soil cover in high severity burn areas, reduce erosion and limit damage to roads. Actions taken for BAER did not have measurable effects relative to fuels, fire, or air quality. The Hoedad Planting Project is designed to re-establish young plantations on approximately 557 acres that were lost during the American Fire (Illustration 3). This includes site preparation prior to planting and future release (manual or mechanical removal of competing vegetation). The site preparation is being done to reduce competing vegetation around
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planted seedlings. Since this project reestablishes previously existing young plantations, does not involve salvage of merchantable timber, is widely dispersed and covers approximately two percent of the fire area, it is not considered significant relative to fuels, fire, and air quality. Illustration 3. Hoedad Planting Project Area
The Ford Roadside Hazard Tree Removal Project (Illustration 4) is designed to remove roadside hazard trees (approximately 5 miles or up to 250 acres) within the American Fire area on two motor ways that provide access to large portions of the District and are heavily used by the public. The majority of hazard trees proposed for removal occur in high severity burned areas; however, hazard trees in mixed severity burned areas would also be included wherever burned trees pose a risk to the roadway. Since this project covers approximately one percent of the fire area, it is not considered significant relative to fuels, fire, and air quality. Illustration 4. The Ford Roadside Hazard Tree Removal Project
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The Tahoe National Forest personal use firewood program allows the purchase of a permit to cut and remove wood for fuel from National Forest lands. Most of this material consists of fallen trees found along forest roads, and non-merchantable logs from past logging operations. Unused material left behind by firewood gathering does not contribute significantly to the surface fuel loading due to the dispersed nature of these activities. Areas of the Big Hope Project analysis area not hosting salvage or roadside hazard tree removal operations will be open to seasonal firewood cutting, with activity areas opening after logging operations. Firewood would continue to be removed near forest system roads, resulting in a cumulative reduction of large fuels within the analysis area. Several commercial logging operations on private property within and near the analysis area are currently active. Approximately 5,000 acres, or nineteen percent of the American Fire area, burned on private land within the greater Tahoe National Forest. The California Department of Forestry has approved harvest plans for 3,168 acres, 62 percent of the private land and eleven percent of the overall burned area in 2014. It is unlikely any additional salvage logging will occur on private land, due to topographical constraints and the necessity for expedience when harvesting dead or dying trees. The apparent management strategy for these areas is timber salvage, with rapid reforestation for commercial timber production as a long term goal. Sub merchantable timber and woody debris is being piled and burned on these projects, greatly reducing surface fuel loads. These treatments are expected to positively influence wildfire behavior within and outside of the logged areas. Cumulative Effects Summary for Alternative 1
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The 2013 American Fire dramatically reduced surface fine fuel loads, old deep duff and litter layers, and ladder fuel continuity across a wide area. The Big Hope project, combined with past, present and reasonably foreseeable future actions described above, would have minor cumulative effects on existing and future wildfire characteristics and potentially significant positive cumulative effects on wildfire control operations within the Big Hope analysis area.
Alternative 2, No Action
Direct and Indirect Effects Analysis Under this alternative, no treatments would occur in any areas. The charts illustrating surface fuel loading, amounts of standing snags, and flame lengths in high vegetation burn severity and low/moderate vegetation burn severity presented for Alternative 1 in the preceding sections also display effects for Alternative 2 (displayed as existing condition in the charts). Under Alternative 2, many historically forested areas would not return for decades, replaced by dense shrub and brush fields. Surface and ladder fuels will reestablish and begin to accumulate. Initially, lack of fuels in the burned area generally will not support large high intensity wildfires. As fire killed vegetation falls into a growing volume of live vegetation, wildfires may be expected to grow in intensity, size and suppression difficulty, and the trend of increasing stand replacing wildfire, with associated ecosystem impacts, will not change (Miller et al 2008). Because the Tahoe National Forest Fire Management Plan (TNF FMP) requires all wildfires be fully controlled as soon as possible, naturally occurring low intensity fires will be extinguished upon discovery. As wildfire intensities or a high volume of standing dead trees preclude direct suppression with ground forces, indirect tactics, heavy equipment and aircraft would be utilized. Burned areas and suppression and emergency rehabilitation costs would increase. Cumulative Effects Surface fuel loads will increase as grasses, shrubs and trees re-colonize the burned area and fire killed trees decay and fall. Fine dead surface fuel layers (the result of generations of plant life cycles) take much longer to regenerate. While the large dead standing and fallen snags influence future fire intensity and residence times (the duration of thermal impact of the fire on a specific area) in their immediate vicinity, they do not directly dictate overall fire behavior. Large dead snags primarily affect suppression efforts by posing an unacceptable level of risk to firefighters. Dead snags ignite easily from, and produce airborne firebrands which complicate control measures. Standing dead trees, burning or not, may fall without warning at any time and in any direction. Decayed trees may fall as a direct, unintentional result of typical fire suppression or other forest activities. Fallen trees block existing roads and trails, and may significantly reduce fuel break construction rates and compromise fire control lines. Existing and future projects are the same as those listed in the proposed action. The proposed action’s objectives of reducing the danger and difficulty of managing future wildfires, reducing snag hazards, and reestablishing the fuel characteristics of resilient, fire-adapted forests would not be met. While the beneficial impacts of other past, present, and reasonably foreseeable future actions on fire and fuels management would be realized under the no action alternative, long-term beneficial effects under the proposed action, particularly those related to opportunities for safe and efficient future fire suppression tactics and more rapidly re-establishing forested conditions, would not be realized. The cumulative effect
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under the no action alternative would be a landscape that over the 10-year future cumulative effects temporal scale would be more at risk of wildfires that would be difficult to control due to the high levels of standing and fallen snags and a complex arrangement of fuels.
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DIRECT, INDIRECT, AND CUMULATIVE EFFECTS TO AIR QUALITY Air Quality Standards, Laws and Responsible Agencies Air quality is managed through federal, state, and local laws and regulations. The Environmental Protection Agency (EPA) has the primary federal role of ensuring compliance with the requirements of the Clean Air Act (CAA). The EPA issues national air quality regulations, approves and oversees State Implementation Plans (SIPs), and conducts major enforcement actions. States and local Air Pollutions Control Districts (APCDs and Air Quality Management Districts (AQMDs) have the primary responsibility of carrying out the development and execution of SIPs, which must provide for the attainment and maintenance of air quality standards.
The state of California also sets Ambient Air Quality Standards which must be equal to or higher than the national standards. Since the state of California has an approved SIP, the enforcement of the CAA is primarily carried out by the California Air Resources Board (CARB), with assistance from the EPA in the areas of scientific research, expert studies, engineering designs and money to support clean air programs.
Attainment Status The original Air Quality Act was passed in 1963. This act was followed by the Clean Air Act Amendments in 1970, 1977, and 1990. The Clean Air Act Amendments of 1970, Section 109, requires the EPA to set National Ambient Air Quality Standards for pollutants considered harmful to public health and the environment. These pollutants include carbon monoxide (CO), lead, nitrogen dioxide (NO2), and particulate matter less than 10 microns in diameter (PM10), particulate matter less than 2.5 microns in diameter (PM2.5), ozone, and sulfur dioxide. These are called criteria air pollutants because the agency has regulated them by first developing health-based criteria (science-based guidelines) as the basis for setting permissible levels. One set of limits (primary standard) protects health; another set of limits (secondary standard) is intended to prevent environmental and property damage. A geologic area that meets or surpasses the primary standard is called an attainment area; areas that don’t meet the primary standard are called nonattainment areas. The current attainment status for the Mountain Counties Air Basin, the location of the Big Hope Project is shown in Table 3 below.
Table 3 Current State and Federal Attainment Status For the Mountain Counties Air
Basin* Criteria Pollutant State Attainment
Status Federal Attainment Status
Carbon Monoxide
Unclassified
Unclassified/Attainment
Lead Attainment Attainment**
Nitrogen Dioxide Attainment Unclassified/Attainment
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PM10 Non-attainment Unclassified
PM2.5 Unclassified Unclassifiable/Attainment
Ozone Non-attainment Non-attainment
Sulfur Dioxide Attainment Unclassified
*Source: California Environmental Protection Agency, Air Resources Board
** United Stated Environmental Protection Agency
Non-Attainment Pollutants
Currently, Placer County is not within California state attainment standards for ozone or PM 10. Ozone is a severe eye, nose, and throat irritant and increases susceptibility to respiratory infections. It is an oxidant, and can cause substantial damage to synthetic rubber, textiles, and other materials. Ozone also produces leaf discoloration and cell damage in plants. Ozone is not emitted directly, but is formed by a photochemical reaction in the atmosphere. Ozone precursors, which include volatile organic compounds and oxides of nitrogen (NOX), react in the presence of sunlight to form ozone. Because photochemical reaction rates depend on air temperature and the intensity of ultraviolet light, ozone is primarily a summer air pollution problem. PM10 are particles of solid matter suspended in air. Sources of PM10 can be manmade or natural. Naturally occurring PM10 may originate from dust, wildfires or plant pollen. Human activities, such as the burning of fossil fuels in vehicles, prescribed fire and heavy traffic on dirt roads can also generate significant amounts of PM10. Increased levels of fine particles in the air are linked to health hazards such as heart disease, altered lung function and lung cancer.
Estimating Emissions The NEPA Air Quality Analysis Desk Reference (CH2M Hill 1995) is a planning guide developed for the Forest Service to assist in estimating air pollutant emissions for projects and activities such as the Big Hope Project. For the Big Hope Project, tables and formulas from the guidebook were used to estimate the direct air quality effects from the action alternatives, which include prescribed burning and equipment emissions. Inputs are based on stand data, on fuel characteristics, typical prescribed burning conditions, and the volume of material estimated to be removed or burned after treatments have been completed. Emissions estimates of PM10, PM2.5, CO, volatile organic compounds (VOC), and oxides of nitrogen (NOX) are summarized below. All referenced are from the above guidebook. Equipment hours are based on average production rates for similar projects. These outputs are used as the principle indicator of air quality impact. Estimated annual maximum PM10, PM2.5, CO, VOC, and NOX emissions for the Big Hope Project under the action alternative is illustrated in Chart 3. Since the alternative based emissions will be spread over several years, implementation of any alternative is not expected to exceed deminimus thresholds for these criteria pollutants. Emissions will be minimized by the mitigation measures listed below.
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Chart 3.
Mitigations Prescribed Burning
The American River District does not expect a significant increase in the amount of prescribed fire activity in the future. Air quality requirements and other weather related constraints are expected to limit the amount of prescribed fire in a given year to levels similar to the range of activity of the last 10 years. In the 2013-2014 burning season the district applied prescribed fire to approximately 165 acres. While there is the potential for an increase in prescribed fire activity in the Mountain Counties airshed, the same restrictions that affect the program on the American River District are likely to limit activity on adjacent federal, state and private lands. State air quality requirements related to prescribed fire are very strict and the regulation of such burning activity is likely to increase. The District is also using more mechanical fuel treatment methods (such as biomass removal and mastication) to reduce the potential for air quality problems associated with prescribed burning.
During the implementation of the Big Hope Project any required air quality coordination would take place between the Forest Service and the Placer County Air Pollution Control District (PCAPCD). This air quality coordination would follow the Smoke Management Guidelines for Agricultural and Prescribed Burning contained in Title 17 of the California Code of Regulations. These Guidelines are intended to provide for the continuation of agricultural burning, including prescribed burning, as a resource management tool, and provide increased opportunities for prescribed burning and agricultural burning, while minimizing smoke impacts on the public. The regulatory actions called for are intended to assure that each air district has a program that meets air district and regional needs.
The Smoke Management Guidelines include a daily burn authorization system that would regulate prescribed burning implemented under Big Hope Project action alternative. This
1
10
100
1000
PM-10 PM-2.5 CO VOC NOx
Big Hope Annual Emissions Outputs (Tons)
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authorization system is designed to minimize smoke impacts on smoke sensitive areas, avoid cumulative smoke impacts, and prevent public nuisance. The burn authorization system would not allow more burning on a daily basis than is appropriate for the meteorological or air quality conditions. The system specifies the amount, timing and location of each burn event. The burn authorization system is required to consider the following factors as necessary:
• Air Quality.
• Meteorological conditions expected during burning, including wind speeds and directions at the surface and aloft, and atmospheric stability.
• Types and amounts of materials to be burned.
• Location and timing of materials to be burned.
• Locations of smoke sensitive areas.
• Smoke from all burning activities, including burning in neighboring air districts or regions which may affect the district or region.
Mitigation Measures to reduce Smoke Emissions from Prescribed Fire: Proper mitigation measures to meet air quality requirements would be implemented under the Big Hope Project. A prescribed fire planner would coordinate with the PCAPCD to mitigate emissions from Fuel reduction burning. Burning permits would be acquired from the PCAPCD. The Air Quality District would determine permissive burn days. The CARB provides daily information on “burn” or “no burn” conditions. Burn plans would be designed and all fuel reduction burning would be implemented in a way to minimize particulate emissions. Prescribed fire implementation would coordinate daily and seasonally with other burning permittees both inside and outside the forest boundary to help meet air quality standards. Because of the mitigation measures applied and coordination with the CARB, any impacts are expected to be minimal. Particulate emissions from prescribed fire would be minimized by utilizing one or more of the following techniques:
Reduction: 1. Limit total mass of material burned
• Lop and scatter, chip (biomass) and masticate activity fuels in high intensity burn areas. • Whole tree yard activity fuels in salvage and hazard tree removal units. • Make activity fuels available for biomass utilization where feasible.
2. Encourage high-efficiency combustion:
• Encourage the flaming phase of combustion. • Limit the smoldering phase of combustion. Dilution: 1. Reduce the rate of release of emissions per unit area.
• Stagger ignitions temporally and spatially.
2. Burn during optimum meteorological conditions.
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• Moderately unstable atmospheric conditions are optimum for mixing and dispersion of emissions.
• Minimize burning when down slope flows of cool dense air may cause smoke to concentrate in low areas.
3. Coordinate daily and seasonally with other burning permittees both inside and outside the forest boundary to help meet air quality standards.
Class 1 Prevention of Significant Deterioration (PSD) Areas.
Class 1 areas include all international areas and National Parks greater than 6000 acres, national wilderness areas greater than 5000 acres that existed on August 7, 1977. This class provides the most protection to pristine lands by severely limiting the amount of additional man-made air pollution, which can be added to these areas. The closest Class 1 PSD area to the Big Hope Project site is the Desolation Wilderness which is about 25 miles southeast of the project area. Prevailing winds, local topography, the limited volume of potential pollution outputs from dust and prescribed fire smoke from the Big Hope Project, and the distance from the project area would make any impact to this Class 1 area unlikely.
Control of Dust
Fugitive dust could be caused by the construction and reconstruction of roads, skidding of logs, and biomass material, hauling operations on native or aggregate surfaced roads, and road maintenance and repair activities. Dust abatement techniques would be applied as necessary to all these activities to minimize unsafe conditions and meet air quality requirements. The primary techniques used for dust abatement is:
• The application of water during operations
• Application of dust palliatives such as magnesium or calcium chloride to roads to reduce dust as necessary
Because of the size of the Big Hope Project area, the small amount and dispersed nature of dust producing activities, and the favorable weather conditions within the normal operating season, in combination with the dust abatement techniques used, any adverse effects from dust are expected to be minimal.
Diesel Engine and other Motor Vehicle Emissions The potential for adverse effects from emissions from diesel engines and other motor vehicle is very low because of the relatively small number of vehicles from all forms of activities in the project area. The project area is a very rural environment with a minimal amount of commercial or residential development. It has a high level of air quality year-around. Recreational activity and forest management activities such as timber harvests are widely dispersed temporally and spatially on both National Forest and private land. In addition, the Federal and State requirements designed to protect and maintain air quality for diesel and other motor vehicle engines are applicable to all the equipment and recreational vehicles that operate within the project area. For these reasons, any adverse effects from the exhaust associated with diesel and other motor vehicles are expected to be minimal to the point of non-significance.
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Cumulative Effects on Air Quality. The Big Hope Project is dispersed through a large rural mountainous area with a low population density. Air quality is good throughout the year. The primary human activities that might affect air quality are logging and other construction activities that produce dust or the use of prescribed fire. Because this project area is large and the expected activities would be widely dispersed over space and time, and mitigations measures would be applied, both activity generated dust and smoke from prescribed fire that would result from cumulative past, present and future foreseeable actions are expected to remain at levels that meet both state and federal air quality standards for this area.
Because of the distances from the proposed project area, the nature of prevailing winds and the amount and timing of occurrences of dust and smoke, no communities are expected to experience adverse air quality effects from actions proposed by the Big Hope Project. Any adverse effects from prescribed burning would be minimized by the implementation of air quality regulation requirements and the standard mitigation measures applied to the application of prescribed fire on the American River Ranger District and adjacent National Forest, public and private lands.
Because of the distances from other potential sources of smoke (El Dorado National Forest and privately owned forest land), and the nature of the prevailing winds, cumulative smoke effects from these other sources in combination with the potential effects from the Big Hope Project are very unlikely
Since the proposed action would follow the Smoke Management Guidelines for Agricultural and Prescribed Burning contained in Title 17 of the California Code of Regulations it is expected that the current high level of air quality in the Big Hope Project Area and the American River Ranger District would be maintained. Overall smoke emissions from prescribed fire on the American River Ranger District are expected to remain within a range similar to the current level. The actual amount of emissions would vary from year to year based on weather and fuel conditions, and on the requirements for smoke management that result from coordination with the California Air Resources Board (CARB) within the Mountain Counties Air Quality Management District.
Increasingly, the American River Ranger District has used alternative methods to prescribed fire, such as thinning and biomass removal, that result in a net decrease in the potential for smoke emissions from forest fuels from both prescribed fire and wildfire.
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Definitions of Terms Used
Biomass. Commercial, pre-commercial or fuels treatment activity generated woody materials (brush, slash, etc.), in this case available for removal as an alternative fuel source.
Fine Dead Surface Fuel Loads. The sum of all dead surface fuels less than three inches in diameter including forest duff, litter, twigs and branches, expressed in tons per acre. Ladder Fuels. Continuous flammable vegetation occurring between the surface fuels and the canopy. Presence of ladder fuels increases the likelihood of crown fires and tree mortality within a stand. Masticate, mastication. A method of vegetation/fuels treatment where understory vegetation (shrubs and saplings) is mechanically shredded and scattered. Mastication eliminates ladder fuels but does not reduce surface fuel volumes. Mid-Flame Windspeed. The velocity of the winds taken at the mid-height of the flames. Mid-Flame Windspeed will directly affect the direction of movement of the flaming front and is important in fire spread calculations. The midflame windspeed is determined by fuel overstory exposure and surface fuel characteristics. Rates of (Fire) Spread. The relative activity of a fire in extending its horizontal dimensions. In this case, it is expressed as rate of forward spread of the fire front in feet per minute. Surface Flame Lengths. The length of the flame in a spreading surface fire within the flaming front. Flame length is measured from midway in the combustion zone to the average tip of the flames. Whole Tree Yarding. A method of commercial or pre-commercial thinning where the majority of activity fuels (limbwood, leaves etc.) are transported to landings for future disposal (burning or biomass utilization).
References Safford, H.D., K. van de Water, and D. Schmidt. 2011. California Fire Return Interval Departure (FRID) map, 2010 version. USDA Forest Service, Pacific Southwest Region and The Nature Conservancy-California. URL: http://www.fs.fed.us/r5/rsl/clearinghouse/r5gis/frid/ Miller, J. D., & Thode, A. E. (2007). Quantifying burn severity in a heterogeneous landscape with a relative version of the delta Normalized Burn Ratio (dNBR). Remote Sensing of Environment, 109, 66−80. USDA Forest Service. 1990. Tahoe National Forest Land Resource Management Plan (posted for amendments) (pages 564, 591, 595, 600, 622, 628, 647). Sierra Nevada Forest Plan Amendment: Final Supplemental Environmental Impact
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Statement – Record of Decision. 2004. USDA Forest Service, Pacific Southwest Region. R5-MB-046. Dixon, Gary E. comp. 2002. Essential FVS: A user’s guide to the Forest Vegetation Simulator. Internal Rep. Fort Collins, CO: U. S. Department of Agriculture, Forest Service, Forest Management Service Center. 226p. (Revised: January 17, 2013) Brown, James K.; Oberheu, Rick D.; Johnston, Cameron M. 1974. Handbook for inventorying surface fuels and biomass in the Interior West. Gen. Tech. Rep. INT-129. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experimental Station. 48 p. Brown, James K. 1980. Influence of harvesting and residues on fuels and fire management. In: Proceedings, Environmental consequences of timber harvesting in Rocky Mountain coniferous forests; 1979 September 11-13; Missoula, MT. Gen. Tech. Rep. INT-90. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station: 417-432. Angwin, Peter a, Daniel R. Cluck, Paul J. Zambino, Brent W. Oblinger, William C. Woodruff, (2012). Hazard Tree Guidelines for Forest Service Facilities and Roads in the Pacific Southwest Region. US Forest Service, Pacific Southwest Region Report # RO-12-01. Smith, Sheri L and Daniel R. Cluck, (2011). Marking Guidelines for Fire-Injured Trees in California. US Forest Service, Pacific Southwest Region Report # RO-11-01. Deeming, J.E. 1977. The National Fire Danger Rating System. Gen. Tech. Rep. INT-GTR-39. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 63 p p. Finney, Mark A., (1999). Design of Regular Landscape Fuel Treatment Patterns for Modifying Fire Growth and Behavior. Forest Science 47(2). USDA Forest Service, Rocky Mountain Research Station Collins, Brandon M., Jay D. Miller, Andrea E. Thode, Maggi Kelly, Jan W. van Wagtendonk, Scott L. Stephens, (2008). Interactions Among Wildland Fires in a Long-Established Sierra Nevada Natural Fire Area. Ecosystems DOI:10.1007/s10021-008-9211-7. Miller, J. D., H. D. Safford, M. Crimmins, and A. E. Thode, (2008). Quantitative Evidence for Increasing Forest Fire Severity in the Sierra Nevada and Southern Cascade Mountains, California and Nevada, USA. Ecosystems DOI: 10.1007/s10021-008-9201-9. USDA Forest Service. 2008. Tahoe National Forest Fire Management Plan (Page 4). CH2M Hill 1995. A desk reference for NEPA Air quality analyses. Prepared for Forest Service, U.S. Department of Agriculture; March 1995.
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