Vegetation and Silviculture Resource Report

Transcription

1 Bluff Mesa Hazardous Fuels Reduction Project Vegetation and Silviculture Resource Report Prepared for: Mountaintop Ranger District San Bernardino National Forest Prepared by: Joe Iozzi Silviculturist and Randy Fairbanks Forest Scientist February 2011

2 TABLE OF CONTENTS Introduction... 1 Issues Addressed and Environmental Components Analyzed... 1 Methodology... 2 Regulatory Direction... 2 Forest Goals and Desired Conditions... 2 Strategic Management Direction... 3 Guidance for Designing Actions and Activities... 4 Affected Environment... 6 Existing Vegetation... 6 Environmental Consequences Measures for the Effects Analysis No Action Alternative Proposed Action Treatment Level Treatment Level Treatment Level Treatment Level Borax application... Implementation of Design Features and Mitigation Measures... Direct and Indirect Effects... Cumulative Effects... References Appendix A - Stand Tables... Appendix B Comparison of Proposed Action and Diameter Cuts The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C , or call (800) (voice) or (202) (TDD). USDA is an equal opportunity provider and employer.

3 Introduction The Bluff Mesa Hazardous Fuels Reduction Project Vegetation and Silviculture Resource Report outlines the regulatory direction, the desired condition under the San Bernardino National Forest Land Management Plan (LMP), and provides an assessment of the current condition of the project area, and the potential effects of implementing the proposed action and the alternatives. The report utilizes information from previous fuels reduction analyses, recent stand exams, spatial data, and scientific studies related to silviculture and the environment in the Bluff Mesa project area (included in the project record). Issues Addressed and Environmental Components Analyzed The current issues relevant to silviculture within the Bluff Mesa Hazardous Fuels Reduction Project area were developed based on internal review and external scoping comments from the public. The primary issues surrounding silviculture are related to A) vegetation conditions, B) forest health, and C) human and ecological risk associated with fungicide application. The environmental components and indicators used to describe potential effects associated with these issues are summarized in Table 1 Table 1. Timber and vegetation issues addressed and environmental components analyzed within the Bluff Mesa Project Area Issue Desired Condition Summary Forests have a species mix more similar to pre-settlement composition, with a higher percentage of shade-intolerant species, especially pines. Stand densities are similar to those that existed prior to fire suppression (a canopy cover of 20 to 40 percent on drier slopes, less than 50 percent where Jeffrey pine once formed open, fire-maintained woodlands, and 50 to 80 percent on the most productive sites. Stands contain larger diameter trees. Environmental Component Indicator Vegetation Conditions Species Composition Density Large Tree Structure Representation of shade-intolerant tree species within the montane conifer forest. Specifically, the relative proportion of Jeffrey pine (shade intolerant) and white fir (shade tolerant) in terms of number of trees per acre. Representation of historic, firemaintained tree densities within the montane conifer forest as indicated by average canopy closure and number of trees per acre by size class. Representation of large-tree structure within the montane conifer forest as indicated by average stand diameter and density of trees > 24 and 36 in dbh. Forest Health Forests are more resistant to the effects of drought, insect and disease outbreaks, and stand-killing fires; they have species composition, stand density, and structure similar to conditions prior to widespread fire suppression. Resistance to: Effects of drought Insect and disease outbreaks Stand-killing crown fire Species composition, density, and structure in the montane conifer forest that exhibit resilience and the ability to survive disturbance without long-term loss of functional or structural elements. Measures include tree densities (trees per acre), relative densities by species, and size class distribution. Fungicide Application Forests do not suffer from widespread root rot and human health is not affected by treatments. Root rot Ecological and human risk, as measured by the area infected by Heterosbasidion annosum root disease and the potential for human exposure to treatments. Bluff Mesa Hazardous Fuels Reduction Project 1

4 Methodology Sources of vegetation information and data are: CalVeg vegetation mapping data, aerial photography (September 2003), and stand exam and diagnosis (2008 and 2009). Forest stand exams did not include canopy cover measurements; therefore, tree canopy cover was estimated for each tree in each plot using dbh/crown-width equations developed by Paine and Hann (1982). Regulatory Direction The San Bernardino LMP (USDA Forest Service 2005a, 2005b, 2005c) provides direction for the management of forest vegetation in the San Bernardino National Forest (SBNF). It consists of three parts that work together to facilitate the development of management activities. These parts include: forest goals and desired conditions for resources; strategic management direction; and guidance for designing actions and activities (design criteria). Forest Goals and Desired Conditions This section includes a discussion of forest goals and desired conditions relevant to silviculture (USDA Forest Service 2005a, pp ). The goals are responsive to both national priorities and the management challenges identified for the SBNF. Goal 1.1: Improve the ability of southern California communities to limit the loss of life and property and recover from high-intensity wildfires that are a natural part of the states, ecosystem. Goal 1.2: Restore forest health where alteration of natural fire regimes have put human and natural resource values at risk. Goal Reduce the potential for widespread losses of montane conifer forests caused by severe, extensive, stand replacing fires. Goal 6.2: Provide ecological conditions to sustain viable populations of native and desired nonnative species. Management Indicator Species (MIS) are selected because their population or habitat trends are believed to indicate the effects of management activities (36 CFR (a)(1) [1982]; 36 CFR [2005], and as a focus for monitoring (36 CFR (a)(6) [1982]). Three MIS were selected from Montane Conifer Forest, including two tree species: White Fir and California Black Oak. Desired conditions for the montane conifer forest include: Create forests that are more resistant to the effects of drought, insect and disease outbreaks, and stand-killing fires by restoring species composition, stand density, and structure to levels that existed prior to widespread fire suppression. Create forests that contain a species mix more similar to pre-settlement composition, with a higher percentage of shade-intolerant species, especially pines, and a lower degree of encroachment by shade tolerant white fir. Recreate stand densities similar to those that existed prior to fire suppression (a canopy cover of 20 to 40 percent on drier slopes, less than 50 percent where Jeffrey pine once formed open, firemaintained woodlands, and 50 to 80 percent on the most productive sites (San Bernardino LMP, pp 84-85). Encourage a stand structure that contains large-diameter trees. Bluff Mesa Hazardous Fuels Reduction Project 2

5 Strategic Management Direction The SBNF is divided into a series of geographical units called Places. Each Place has its own character and the LMP describes a theme, setting, desired condition and program emphasis (USDA Forest Service 2005b). The vast majority of the Bluff Mesa project area lies in Big Bear Place; however, the southeastern lobe of the project area, below the ridgeline, falls within the San Gorgonio Place. Big Bear Place Big Bear Place provides management emphasis at different levels for a variety of resources found within the project area. The following desired condition and program emphasis descriptions are pertinent to silvicultural resources for this project as it applies to the Big Bear Place (USDA Forest Service 2005b, pp ): Desired Condition: Big Bear Place is maintained as a rural, natural appearing landscape that functions as a recreation setting for water-oriented summer recreation and the surrounding mountains for winter sports activities. The valued landscape attributes to be preserved over time include the big-tree conifer forests to provide the alpine character, the lodgepole pine forests, and the rocky base of terrain providing numerous outcrops. Chaparral and forested areas are managed to provide fire protection for adjacent communities, recreation areas, and wildlife habitat. Habitat conditions for threatened, endangered, proposed, and sensitive species are improving over time; invasive nonnative species are reduced. Program Emphasis: Community protection from wildland fire is of the highest priority, and will be emphasized through public education, fire prevention, and fuels management. Forest health projects will be implemented to remove dead trees and reduce stand density that will result in a more natural pattern of low intensity fires and return intervals. In addition, these projects will focus on returning forest ecosystems to a more healthy condition. Reforestation projects will maintain tree diversity. San Gorgonio Place San Gorgonio Place provides management emphasis at different levels for a variety of resources found within the project area. The following desired condition and program emphasis descriptions are pertinent to the silvicultural resource for this project as it applies to the San Gorgonio Place (USDA Forest Service 2005b, pp ): Desired Condition: San Gorgonio Place is maintained as a naturally evolving and natural appearing landscape that functions as an alpine recreation setting containing wilderness and a wilderness portal. The valued landscape attributes to be preserved over time include the craggy silhouettes of the mountain peaks, the wind-carved alpine character, montane meadows, the ponderosa pine, mixed conifer, well-defined age-class mosaic in chaparral, the occurrence of rock outcrops, and natural appearing views from the scenic byway. Chaparral and forested areas are managed to provide fire protection for adjacent urban communities, recreation areas, and wildlife habitat, and to protect from type conversion to grass. Habitat conditions for threatened, endangered and sensitive species are improving over time. Habitat linkages are intact and functioning. Invasive nonnative plants are reduced over time. Program Emphasis: Community protection from wildland fire is of the highest priority. It will be emphasized through public education, fire prevention, and fuels management in cooperation with city, county and state agencies. Forest health projects will be implemented to remove dead trees, reduce stand density and promote pre-fire suppression era fire return intervals. Reforestation projects will maintain forest diversity. Enhancement of plant and wildlife habitat and linkage corridors for threatened, endangered and sensitive species will be emphasized in all Bluff Mesa Hazardous Fuels Reduction Project 3

6 management activities. An active program of prescribed burning/fuelbreak maintenance is expected to result in quality deer winter/summer range. Wildlife corridors will be maintained or enhanced. Guidance for Designing Actions and Activities The LMP describes design criteria or the rules that must be followed in implementing actions or activities (LMP, Part 3 Design Criteria for the Southern California National Forests). The first component of design criteria are the LMP standards that represent the fundamental requirements that define the parameters applicable to specific actions or activities. The second component are the laws, policies, and other direction that may be applicable to proposed actions or activities. Forestwide Standards Forestwide standards for silviculture in the LMP, Part 2 that are applicable to the Bluff Mesa project are shown in Table 2. Table 2. Relevant Forestwide Standards Associated with Silviculture and applicable to the Bluff Mesa Project (USDA Forest Service 2005b). Standard No. S1 S2 S3 S4 S5 S7 S8 S14 S15 Standard Long-Term Sustained Yield (36 CFR (c) (2)). No land is currently identified as suitable for timber sale production on Southern California National Forests, the allowable sale quantity (ASQ) is zero. Harvest may occur to meet wildlife, fuels, watershed or other needs. Appropriate Vegetation Management Practices (Including Limitations on Even-Aged Timber Harvest Methods) (36 CFR (c) (6)) include stocking control (thinning) and salvage of dead material, reforestation/restoration, and tree improvement in forest types found in the project area. Ground-based harvest systems will normally operate on slopes up to 35 percent, and on short steep pitches up to 50 percent. Ground based equipment will be used on steep slopes when supported by site and operation specific analysis. Cable or aerial systems will generally be used on sustained slopes greater than 35 percent. Maximum Size Openings Created by Timber Harvest (36 CFR (d) (2)). The maximum allowable opening acreage for the forest types present is 3 acres. This limit shall not apply where harvests are necessary as a result of catastrophic conditions, such as fire, insect and disease attack, windstorm, or drought. Design fuelbreaks in forests to be open; averaging no more than 40 percent crown closure along the center corridor with an understory of grasses, forbs, and small shrubs. Thinning of forests should favor retention of large-diameter trees. Crown closure and understory vegetation increase gradually, moving from the inside toward the outside of the shaded fuelbreak. Treat all freshly cut live or recently dead conifer stumps with a registered fungicide to prevent the establishment of annosus root disease. The minimum width for Wildland/Urban Interface (WUI) Defense Zones (as described by the Healthy Forests Restoration Act of 2003) for forested areas is 300 feet, the maximum width is 1,500 feet. Community protection needs within WUI Defense Zones take precedence over other requirements of other Forest Plan direction. Expansion beyond the minimum 300-foot width will be designed to mitigate effects to other resources to the extent possible. Where available and within the capability of the site, retain a minimum of 6 downed logs per acre (minimum 12 inches diameter and 120 total linear feet) and 10 to 15 hard snags per 5 acres (minimum 16 inches DBH and 40 feet tall, or next largest available). Exception allowed in WUI defense zones, fuelbreaks, and where they pose a safety hazard. Within riparian conservation areas retain snags and downed logs unless they are identified as a threat to life, property, or sustainability of the riparian conservation area. Bluff Mesa Hazardous Fuels Reduction Project 4

7 Program Strategies and Tactics Table 3 lists some of the San Bernardino National Forest program strategies and tactics that are most relevant to the Bluff Mesa Project (identified in the LMP, Part 2, Appendix B). Table 3. Relevant Additional Design Criteria Associated with Silviculture (USDA Forest Service 2005b, Appendix B). Additional Design Criteria Use vegetation management practices to reduce the intensity of fires and habitat loss due to catastrophic fires (WL 1). Thin conifer stands to prevent water stress and damage by bark beetles (FH 4). Implement vegetation management activities to reduce tree densities and fuel loading in Jeffrey Pine and mixed conifer forests to levels similar to those that characterize the forests of pre-suppression and early suppression eras. Restore species composition comparable to forests of the same eras with an emphasis on increasing the relative abundance of large-diameter shade intolerant species (FH 3). Treat fuel loading in montane chaparral to reduce the likelihood that fires originating in this type will generate crown fires in adjacent forested stands (FH 3). Manage chaparral in selected locations to protect life and property, to improved wildlife forage, and to protect watersheds from adverse impacts of large, destructive, high-intensity fires (FH 3) Direct Community Protection: Reduce the fire threat to communities using mechanical treatments, prescribed fire, and herbicides. Identify and schedule treatments for high risk and high value acres near communities, including the installation of Wildland/Urban Interface (WUI) Defense and Threat Zone vegetation treatments. Highest priority should be given to those evacuation routes, WUI Community Defense and Threat Zones, and communication site areas with substantial drought and insect-killed vegetation that present a significant threat to life and property in entire communities (Fire 2). Fuel breaks and Indirect Community Protection: Consider constructing new fuel breaks on land outside of wilderness or other special designations (Fire 5). Vegetation Management Treatments Treatments in the WUI Defense and Threat zones and resource protection areas may include the following vegetation management activities or combination of these vegetation management activities (as described in the LMP, Part 2, pgs ): Mortality Removal Removal of dead or dying vegetation to reduce fire hazard. Thinning Removal, mastication, shredding, or cutting of living trees from dense, overgrown stands. This treatment type usually includes follow-up removal of slash (small and medium diameter pieces of downed wood created from removal of trees) and is proven to move forests to more fire resistant conditions. Thinning is usually required prior to prescribed fire treatments. Shaded Fuelbreaks Planned shaded fuelbreaks are along roads and ridge-tops. Most fuelbreaks are constructed with hand or machine removal of vegetation and tree thinning, with follow-up maintenance using mechanical treatments or prescribed fire to kill re-sprouting vegetation. Fuelbreaks are designed to limit wildfire size by strategically removing fuels to limit fire spread at key topographical areas and to keep fires from spreading onto private lands. Prescribed Fire Prescribed fire may be implemented by burning piles of downed woody debris or broadcast burning (burning woody debris within a contained area across the forest floor) to reduce fuels such as downed woody debris and small trees, and remove low-lying branches of larger trees. Prescribed fire is a useful tool for maintaining the fire resistance and resilience of forested areas and may be applied to treatment areas as often as every 2 to 5 years. Bluff Mesa Hazardous Fuels Reduction Project 5

8 Affected Environment The Bluff Mesa Fuels Reduction Project area is approximately 1,600 acres and is located about 3 miles southeast of Big Bear Lake on the Mountain Top Ranger District of the San Bernardino National Forest (SNBF) in Southern California. It sits at the headwaters of Siberia Creek, a 5th field watershed which terminates at Bluff Lake. Bluff Lake is a 12-acre artificial lake, surrounded by about 120 acres of private land owned by the Wildlands Conservancy within the project area. The Wildlands Conservancy has numerous buildings and operates an environmental camp during the summer months. Existing Vegetation Composition and Structure The project area includes approximately 1,600 acres, occurring mostly between 7,500 and 8,000 ft. above mean sea level. It primarily contains two vegetation cover types: montane conifer forest and montane chaparral. Montane conifer forest covers the majority of the flatter portions of the mesa, while montane chaparral covers much of the steeper slopes on the south and west edges of the project area. Montane meadows also occur along Siberia Creek and a few stringers of riparian vegetation also occur. Table A-1 in Appendix A provides a summary of stand data based on stand exams completed in 2008 and Figure 1 shows the 30 mapped stands of the project area. The montane conifer forest is dominated by Jeffrey pine (Pinus jeffreyi) and white fir (Abies concolor var. lowiana), with lesser amounts of sugar pine (Pinus lambertiana) and ponderosa pine (Pinus ponderosa). Most of the area is covered by an older, relatively open forest consisting of multiple age classes. The shrub layer is relatively dense in many areas, and consists of the same species that occur in the montane chaparral type. Forests are variable in density, with open stands and stands of dense forest. Old skid trails, landings, and stumps are scattered throughout the montane conifer forest type which has been selectively logged. Table 4 presents a summary of characteristics for montane conifer forests in the project area. Most forest stands contain a number of large trees, typically in the range of 2 to 5 trees per acre, greater than 36 inches in diameter-at-breast-height (dbh). Forest stands contain 5 to 21 trees per acre greater than 24 inches dbh (average = 13), plus an average of 2 dead trees per acre in this size category. For comparison, in 1932 there was an average of 20 trees per acre greater than 24 inches dbh in mixed Jeffrey pine forests on the San Bernardino National Forest (Minnich et al. 1995). The trees greater than 24 inches dbh typically consist of 69 percent Jeffrey pine and 28 percent white fir, with the remainder consisting of other pines. Overall tree canopy closure in the montane conifer forests is relatively high, ranging from about 30 to 90 percent in most forest stands. Historically, montane conifer forest canopy closure ranged from 20 to 40 percent on drier slopes and was less than 50 percent where Jeffrey pine formed open, fire-maintained woodlands (San Bernardino LMP FEIS Volume 1). Current average tree canopy closure in the montane conifer forests (dominated by Jeffrey pine) in the project area is 58 percent. Shrub cover in the forest stands ranges from about 15 to 70 percent. Small areas of dense, younger pine forests are also included within the project area. Most of these are 20- to 40- year-old stands and are the result of plantations following the Bear Fire and other disturbance events; tree crown closure in those plantations is up to 100 percent. Bluff Mesa Hazardous Fuels Reduction Project 6

9 Figure 1. Mapped Stands in the Bluff Mesa project area. Bluff Mesa Hazardous Fuels Reduction Project 7

10 Table 4. Characteristics of Bluff Mesa Project Area Stands. General Cover Type 1/ # Stands and Acreage Trees per Acre (TPA) Category White Fir Live Trees per acre Jeffrey & Ponder. Pine Sugar Pine Other Total Live Trees Total Dead Trees per acre Tree Canopy Closure Shrub Canopy Cover Avg. Tree Canopy Base Height (ft.) Total TPA < Montane Conifer Forest Stands 21 stands 1,211 acres TPA >=6" < TPA >=24" 3 9 <0.5 < % 43% 12 TPA >=36" 1 2 < Total TPA Montane Chaparral Stands 7 stands 300 acres TPA >=6" TPA >=24" <0.5 16% 65% 13 TPA >=36" <0.5 < / Note that 2 stands in the project area are mapped as Montane Meadow and are not included in this table. Montane chaparral or shrub-dominated areas cover the majority of the southern and western edges of the project area and result from previous fires (Figure 2). The process of natural reforestation following crown fire appears to be very slow when the area becomes dominated by chaparral. Dominant species are manzanita (Arctostaphylos spp.), mountain whitethorn (Ceanothus cordulatus), and chinqapin (Chrysolepis sempervirens) that form almost impenetrable stands in some areas. Residual trees and tree seedlings and small forest patches occur in most areas mapped as montane chaparral stands. Shrub cover ranges from about 40 to 90 percent and tree cover ranges from about 5 to 30 percent. Table 4 presents a summary of characteristics of the project area stands that are dominated by montane chaparral. Montane meadows, which are grass- and herb-dominated plant communities, occur at some locations, primarily along Siberia Creek and Bluff Lake. A large meadow occurs on private land within the project boundaries, just east of Bluff Lake. A small portion of this meadow continues onto National Forest System (NFS) land on the west and east sides of the lake (stands 008 and 012 in Figure 1). Periodic fires are necessary to maintain these meadows and kill invading shrub and tree species. In the absence of periodic fires, the meadows will shrink in size. Several ESA- Bluff Mesa Hazardous Fuels Reduction Project 8

11 listed plant species are associated with these meadows. Lodgepole pines occur along the edges of the meadows, including one specimen that is one of the largest known lodgepole pines in existence (116 feet tall and 78 inches dbh). Narrow stringers of riparian vegetation occur along some drainages. Tree-size willows, primarily Scouler s willow (Salix scouleriana), occur within some riparian areas. Management Indicator Species Black Oak (Quercus kelloggii) California black oak was selected as an MIS in montane conifer forests and is being monitored to answer the question, Is fire or other disturbance occurring too infrequently in mid-elevation conifer stands to allow black oak and other shade-intolerant species to persist over time? Black oak is a gap-phase species that requires occasional openings in the forest canopy in order to regenerate. Its acorns are also an important food source for many forest animal species (California Department of Fish and Game 2002). Abundance of black oak, especially saplings, will indicate progress toward reducing forest stand densities and creating regeneration opportunities for light requiring tree species. This species is relatively rare in the immediate project area, likely because the majority is above its optimal elevation range. No black oaks were identified in the stand exam plots measured throughout the project area in White Fir (Abies concolor var. lowiana) White fir was selected as an MIS to answer the question, Are management activities changing montane conifer forest tree species composition to achieve density and age/size class distributions more similar to pre-suppression conditions? The abundance of shade-tolerant white fir has increased with the success of fire suppression in montane conifer forests once dominated by Jeffrey pine, ponderosa pine, and black oak (Stephenson and Calcarone 1999); thus it acts as an indicator of forest stand densification. Reduced abundance of small-diameter white fir and welldistributed large-diameter white fir in conifer stands will indicate a return to more historic stand conditions and meet the desired condition for this habitat. White fir is abundant in the project area and is represented by a wide range in age classes. However, white fir makes up the largest percentage of trees in the smaller size classes, except in the pine plantations. Fire Historically, Bluff Mesa was dominated by multi-layered, old-growth stands with large-diameter trees and frequent canopy openings. The more shade tolerant and fire-sensitive species (e.g., white fir) regenerated beneath overstory trees as well as in openings. Periodic fires, however, kept their numbers relatively low, especially in the understory (Weatherspoon et al. 1992). Frequent, patchy, low-to moderate-intensity surface fires maintained this open structure (Minnich et al. 1995), and species composition was dominated by shade-intolerant conifers (Jeffrey pine and sugar pine). Fires returned at intervals averaging 30 to 50 years, maintaining the open understories, reducing the density of shade-tolerant white fir, and favoring the recruitment of Jeffrey pine and sugar pine. This complex fire regime, along with other agents of disturbance (e.g., groups of trees killed by bark beetles), produced a variable, irregular patchwork of evenaged groups, most from less than an acre to several acres in size (Weatherspoon et al. 1992). Bluff Mesa Hazardous Fuels Reduction Project 9

12 For the most part, fires have been kept out of the Bluff Mesa area for the last century. The last major fire that intruded a small finger into the area was the Bear Fire in There have been a few lightning fires in the last 4 decades that were put out quickly. This lower frequency of fire is one reason that there is a growing population of white fir in the understory and a higher shrub cover within the project area. Due to the recent prolonged drought, many of the white fir have died along with stressed Jeffrey pine, which was attacked by insects. The increased fuel loading by these dead trees and the ladder fuels provided by smaller white fir, increases the likelihood of a more severe fire if one should occur. Bluff Mesa Hazardous Fuels Reduction Project 10

13 Figure 2. Recent Fire History and Fuel Treatment in the Project Area and Vicinity. Bluff Mesa Hazardous Fuels Reduction Project 11

14 Tree Mortality Most stands in the project area have experienced some level of tree mortality due to drought, insect attack, and/or disease. Stand exams completed in 2008 and 2009 indicate that there is an average of 5 dead trees per acre for trees 6 inches dbh and larger (the range is 0 to 20 trees per acre). Six stands (269 acres) have more than 10 dead trees 6 inches dbh and larger per acre (Table A-1 in Appendix A). Forest Insects and Pathogens Native insects and pathogens of forest trees perform important functions in natural ecosystems, including creating dead and down woody habitat for other species, recycling nutrients, and creating gaps for regeneration. However, they also increase fuel loading, contributing to fire hazards in forests (Stephenson and Calcarone 1999). Certain conditions can trigger major insect or disease outbreaks that result in substantial tree mortality. Insects and pathogens common to the Bluff Mesa area include: Annosus Root Disease: This fungus colonizes freshly cut conifer stumps and grows down through the woody tissue into the roots. The fungus is of widespread distribution in the North Temperate Zone, usually occurring in conifers, but occasionally in hardwoods. Two kinds of damage are associated with annosus root disease: tree mortality and serious wood loss through butt and stem decay. The incipient decay is a red wine-colored to reddish-brown stain. The stain has an irregular margin and is found in the interior of infected butts and roots. Wood with advanced decay often separates at the growth rings, exposing small (1-2 mm) pits on one side of the laminae. Otherwise, advanced decay is a white spongy rot interspersed with black flecks. Secondary attack of root disease-weakened trees by bark beetles is also common. Infected trees may be windthrown or broken off at the base, but usually die standing. This fungus infects its hosts in one of two ways: 1) by windblown spores deposited and germinating on freshly exposed wood, and 2) by mycelial extensions from diseased to healthy roots via root contacts and graphs. Annosus infection by wind-blown spores can be prevented by treating freshly cut stumps with borax, which contains borate (Stephenson and Calcarone 1999). Pine Beetle: Jeffrey pine beetle (Dendroctonus jeffrey) and mountain pine beetle (Dendroctonus ponderosae) have one generation per year and can attack and kill otherwise vigorous trees when beetle populations are high (Stephenson and Calcarone 1999). Jeffrey pine beetles are most often found in Jeffrey pine and mountain pine beetles in sugar pine. The mountain pine beetle is the most aggressive and destructive pine beetle in the United States. These two beetles became very active in the Big Bear area in 2003 and are responsible for much of the pine mortality visible today (Laura Merrill, Pers. Comm., cited in McCusker and Higgins 2009). Turpentine Beetle: The red turpentine beetle (Dendroctonus valens) infests freshly cut stumps and roots and lower bole of living trees, particularly those damaged by fire or root disease. This species rarely causes tree mortality but does contribute to the decline of trees that are then attacked by more aggressive species (Stephenson and Calcarone 1999). White Fir Pests: White fir is commonly host to a variety of pests, including true mistletoe (Phoradendron spp.), dwarf mistletoe (Arceuthobium abietinum), root diseases (including annosus), fir engraver beetles (Scolytus venralis) and roundheaded fir borer (Tetropoium abietis) (USDA Forest Service 1990). Bluff Mesa Hazardous Fuels Reduction Project 12

15 Ips Beetle: Ips species, also referred to as engraver beetles, that have several generations per year. Ips beetle populations may build up in slash to levels where small diameter trees and tops of mature trees in the vicinity are at risk for attack. Thus, proper sanitation is believed to be essential to the management of these beetles (Stephenson and Calcarone 1999). Past Timber harvest There is evidence of past small-scale timber harvest in the project area. Logging began in the general Big Bear area in the 1870s to supply local needs, but was limited by accessibility and slope. Up until about 1940, logging was limited in extent, confined to small areas (Robinson 1989), and appears to have been very limited in the Bluff Mesa area. Scattered stumps indicate a selective harvest, including the salvage of dead and dying trees, primarily beetle-infested and high-risk trees. Most logging occurred between the 1940s and 1980s. As a result, past skid trails are generally well healed and not always readily visible. Existing Fuel Breaks The Skyline fuel break is a 300-foot-wide fuel break along the east and northeast edge of the project area (Figure 2). It coincides with Roads 2N10 and 2N86 (300 feet on each side of the road). The effectiveness of this fuel break is diminished by the presence of large amounts of untreated fuel to the west of it. If a large fire were to occur to the west, it could easily overcome the fuel break. Bluff Mesa Hazardous Fuels Reduction Project 13

16 Environmental Consequences Measures for the Effects Analysis The alternatives are compared in terms of the following issues: Effects of the alternatives on meeting the desired conditions Effects of the alternatives on density in relation to historic, fire maintained densities in the montane conifer forest Effects of the alternatives on resistance to the effects of drought, insect and disease outbreaks and stand-killing crown fires in the montane conifer forest Effects of the alternatives on large tree structure in relation to representation of trees greater than 24 inches DBH in the montane conifer forest Effects of application of borax to freshly-cut stumps to prevent colonization by spores of Heterobasidion annosum root disease in terms of human and ecological risk No Action Alternative Under the No Action alternative, current management plans would continue to guide management of the project area. No fuels management activities would be implemented to accomplish project goals at this time. Road maintenance and repair and trail maintenance and repair would continue. Direct and Indirect Effects Desired conditions: The No Action Alternative would not contribute toward meeting the desired conditions identified in the Forest Plan. Vegetative conditions, fuel loads and forest health, would not be improved, and would likely continue to decline. Protection of communities in the WUI areas would not be improved. Stand densities would generally remain above desired levels. Stand density/resistance to drought, insects, and disease: Approximately 74 percent of the area occupied by forested stands currently has 50 percent or higher canopy closure, and 38 percent has 60 percent or higher. In addition, there is an overall average of 35 white fir trees per acre less than 6 inches dbh and four stands have more than 100 per acre. In the montane conifer forest, the shift in species composition toward shade-tolerant species (e.g., white fir) would continue, especially in the understory, and average stand densities would increase. These stands would continue to be at higher risk for mortality due to fire, insects, diseases, and drought. In the absence of fire or other disturbance, moderately dense stands would convert to high density stands, with no improvement toward the desired species composition and structure. The risk of bark beetle epidemics would increase during the next drought cycle, which would increase the risk of a stand-replacing crown fire. Average canopy base heights would remain relatively low, shrub cover would remain relatively high, and fuel loading (standing and down) would continue to increase; all of these factors would contribute to the increased risk of catastrophic fire. Recruitment of large trees would be slowed due to the continued density-related decline in tree growth and vigor. Large tree structure: Under the no action alternative, the large tree component within the project area would exhibit low resistance to beetle attack and higher risk of potential mortality from catastrophic wildfire. Mortality within the large tree component may increase due to continued competition from understory trees (Minnich et al. 1995). Losses would be especially Bluff Mesa Hazardous Fuels Reduction Project 14

17 pronounced under drought conditions. Recruitment of large trees would be slowed due to the continued density-related decline in tree growth and vigor. Human or ecological risk from borax application: Under the No Action Alternative, borax would not be applied because there would be no freshly cut stumps that would need to be treated. Therefore, there would be no human or ecological risk from treating stumps with borax. Cumulative Effects There would not likely be any immediate cumulative effects resulting from the No Action Alternative. However, over a period of years, the lack of fuels treatment in the project area would contribute to a greater risk of high-intensity fire in the general area around the project area, including the communities near Big Bear Lake and private property near Bluff Lake. This alternative could contribute to cumulative effects on forests, habitat, property, and human health in the event of a wide-scale catastrophic fire and the associated emergency fire fighting activities. Compliance with Forest Plan and Other Regulatory Direction The No Action Alternative would not be consistent with applicable Forest Plan goals. This alternative would not: Improve the ability of southern California communities to limit the loss of life and property and recover from high-intensity wildfires that are a natural part of the state s ecosystem (Goal 1.1). Fire risk would remain high. Restore forest health, where alteration of natural fire regimes have put human and natural resource values at risk (Goal 1.2). Fuel levels and continuity would remain high. Reduce the potential for widespread losses of montane conifer forests caused by severe, extensive, stand replacing fires (Goal 1.2.1). The majority of stands in the project area would have high density over the long term. Higher fuel levels and fuel continuity would increase the risk of catastrophic fire over the long-term. Provide ecological conditions to sustain viable populations of native and desired nonnative species (Goal 6.2). Conditions leading to a higher risk of catastrophic fire would not contribute to sustaining viable populations. Proposed Action Under the proposed action, the entire project area would be treated by one of eight treatment levels. To meet the primary purposes of providing for firefighter safety, community protection, and reducing the potential for stand-replacing fires, the proposed action includes the creation of a shaded fuelbreak at the top of the ridge along roads and trails near the edge of Bluff Mesa and the creation of narrower shaded fuelbreaks along several internal roads within the project area. Outside of these shaded fuelbreaks, the potential for stand-replacing wildfire would be decreased by reducing tree densities and removing excess surface fuels, while at the same time maintaining essential forest structure required by wildlife. In addition, some roads would be decommissioned while others would be converted from unauthorized roads to system roads. The treatments are shown in Figure 3. A summary of the treatments is provided below. Treatments are defined in terms of treatment objective and desired condition and presented in a comparative format in Table 4. Bluff Mesa Hazardous Fuels Reduction Project 15

18 Treatment Level 1 Treatment Level 1 would be the inner intensive portion of the main shaded fuelbreak to be constructed and it would cover approximately 85 acres. It would be located on top of the ridge near the west and south project area boundaries and would follow existing roads and trails in many locations. The main shaded fuelbreak would provide firefighters a defensible space from which to carry out firefighting operations in order to prevent wildfires to the south and west of the project area from burning rapidly up the ridge in the montane chaparral and then gaining a foothold as a crown fire in the montane conifer forest on top of the mesa. The primary type of treatment used to achieve fuelbreak objectives is mechanical thinning from below (low thinning), leaving the larger diameter trees, but reducing tree density sufficiently to meet the standard of no more than 40 percent crown closure in the defense zone (Forest Plan, Part 3, Appendix K). This type of thinning would result in an open forest structure that facilitates keeping a fire on the ground and out of the tree crowns. Trees would either be left individually spaced apart from each other, or may be in small clumps of two or three trees, where the clump is separated from other trees. In addition, slash and shrubs would be chipped, masticated, or piled and burned leaving only scattered individual shrubs outside the tree drip lines; shrub cover would be 10 percent or less (Figure 6). Prescribed burning may be used to clean up fine fuels. Lower limbs would be pruned from trees up to at least 12 feet. The main Bluff Mesa fuelbreak would include a corridor up to 600 feet wide (300 feet on either side of the roads and trails). Treatment Level 1 would occur down the center 200-ft wide corridor and Treatment Level 2 (see below) would be implemented within the remaining 400 feet width, which includes 200 feet on each side of the center corridor. Treatment Level 2 This treatment would be similar to Treatment Level 1, except less intensive. As noted above, it would be implemented in the outer 400 ft (200 ft on each side) of the Treatment Level 1 corridor. It would also be implemented along several internal roads in the project area, considered strategic as secondary fire-fighting zones, as well as escape routes for firefighters and residents of the private inholding around Bluff Lake. These fuelbreaks would be up to 200 feet wide (100 feet wide on each side of the roads). Thinning from below would be the primary treatment within Treatment Level 2, leaving the larger diameter trees, but reducing tree density sufficiently to produce an average tree crown closure between 40 and 50 percent. Scattered hard snags and down logs would remain in the corridor. Shrub cover would be reduced to 10 percent or less. Altogether, this treatment would cover about 245 acres (171 acres along the main Bluff Mesa fuel break and 74 acres along internal roads). Treatment Level 3 Treatment Level 3 is defined for threat zones outside of shaded fuelbreaks, where there are no special concerns for sensitive biological or cultural resouces.. This treatment level is designed to restore forest conditions similar to those experienced under historic fire regimes. The treatment objective is to reduce the potential for crown fire to be initiated in these stands. Three variations of Treatment Level 3 were developed and are described in the following paragraphs. Bluff Mesa Hazardous Fuels Reduction Project 16

19 Treatment Level 3a: To the west and south of the main shaded fuelbreak, where the vegetation is dominated by montane chaparral with pockets of conifer forest, the potential for standreplacing fires would be reduced and forest health would be improved using Treatment Level 3a. This treatment would cover about 482 acres (about 30 percent of the project area). The focus of this treatment is to break up the continuity of fuels that now exists and change fire behavior under most weather conditions, so that flame length and rates of spread are reduced. In the montane chaparral, this means the removal of up to 50 percent of the existing shrub cover creating a patchy or mosaic pattern. The scattered large trees that exist in these areas would be retained, although some seedlings and saplings would be removed with the shrub cover. In the conifer patches, stands would be opened up by thinning from below. Shrubs would be cleared from under the tree canopies and up to 20 percent of the existing shrub cover would be removed elsewhere. In all areas, sufficient down wood and snags would be retained to meet Forest Plan standards; however, some removal of dead and dying trees would occur. Treatment methods would include mechanical methods and hand clearing. Prescribed broadcast burning would occur in some portions of the chaparral and forest treatment areas, following thinning and the removal of ladder fuels, and after the development of the main fuel break (Treatment Level 1), in order to reduce surface fuels and reintroduce surface fire into the ecosystem. Prescribed burns are managed burns that are conducted only when weather conditions cause a fire to remain mostly on the forest floor and the smoke to be carried away from surrounding communities. Broadcast burns would only occur when weather conditions provide for safe burning around adjacent private property. Treatment Level 3b: This treatment level would be implemented in much of the flat to rolling terrain on top of Bluff Mesa, where the vegetation is dominated by montane conifer forest. As a result, the potential for stand-replacing fires would be reduced and forest health would be improved. This treatment would cover approximately 363 acres (about 23 percent of the project area). Similar to Treatment Level 3a, the focus of this treatment is to break up the continuity of fuels that now exists and change fire behavior under most weather conditions, so that flame length and rates of spread are reduced. In this area of montane conifers, thinning from below would be conducted resulting in more open stands (averaging about 50 percent canopy cover) dominated by large diameter trees. Canopy base height would average 10 to 15 feet. Shrubs would be removed beneath tree canopies and a minimum of 30 percent shrub cover would be maintained where possible. Sufficient down wood and snags would be retained to meet Forest Plan standards; however, some removal of dead and dying trees would occur. Treatment methods would include mechanical methods and hand clearing. Prescribed broadcast burning would occur in some areas, following thinning and the removal of ladder fuels, and after the development of fuel breaks (Treatment Levels 1 and 2), in order to reduce surface fuels and reintroduce surface fire into the ecosystem. Prescribed burns are managed burns that are conducted only when weather conditions cause a fire to remain mostly on the forest floor and the smoke to be carried away from surrounding communities. Broadcast burns would only occur when weather conditions provide for safe burning around adjacent private property. Bluff Mesa Hazardous Fuels Reduction Project 17

20 Table 5. Description of Treatment Levels Treatment level, Width/ WUI zone, and location Fire Behavior Objective Vegetation Type Hard Snag Retention Down Wood Retention Desired Shrub Canopy Cover Desired Stand Structure & Cover Treatment Level 1 Defense zone (85 acres) Fire Behavior Objective: Reduce flame length to 4 feet or less under 90th percentile 1 weather conditions. Shaded fuelbreak 200 ft. wide, along edge of Bluff Mesa Conifer Forest 0 snags; hazard trees would be removed 0 logs/acre (except soft and rotting logs) An average of 10% or less shrub cover The desired condition is an open structure averaging no more than 40% crown closure with an overstory featuring large diameter trees with 20-foot spacing between individual tree crowns (or groups of trees) and an understory of grasses, forbs and small shrubs. Canopy base height averages feet or greater. Montane Chaparral Same as above Same as above Same as above The desired condition is scattered trees emerging from discontinuous patches of chaparral. The canopy base height is 12 feet or greater or up to 50% of the tree height, whichever is less. Treatment Level 2 Defense zone (245 acres) Fire Behavior Objective: Reduce flame length to 4 feet or less under 90th percentile 1 weather conditions. 100 ft wide along both sides of strategic internal roads (important as secondary firefighting zones and as escape routes) and 200 feet wide along both sides of Treatment Level 1. Conifer Forest Montane Chaparral 5 of the largest hard snags per 5 acres; hazard trees would be removed Same as above 3 downed logs per acre (minimum 12 inches diameter, or the largest available, and 60 linear feet). An average of 10% or less shrub cover. The desired condition is an open structure averaging 40 to 50% crown cover with an overstory featuring large diameter trees with 10- to 20-foot spacing between individual tree crowns (or groups of trees) and an understory of grasses, forbs and small shrubs. Canopy base height averages 10 to 15 feet. Same as above Same as above The desired condition is scattered trees emerging from discontinuous patches of chaparral. The canopy base height is 12 feet or greater or up to 50% of the tree height, whichever is less. Bluff Mesa Hazardous Fuels Reduction Project 18