Supplemental Silviculture Report for Cold Canal Vegetation Project Wallowa-Whitman N.F. Wallowa Valley Ranger District

Transcription

1 Supplemental Silviculture Report for Cold Canal Vegetation Project Wallowa-Whitman N.F. Wallowa Valley Ranger District Location: T03S-R45&46E-Multiple Sections County: Wallowa Fifth Field Watershed: Lower & Upper Big Sheep Prepared by: Clint Foster Date: Introduction The Cold Canal Project Area covers 19,387 acres within the Lower and Upper Big Sheep Fifth Field Watersheds on lands administered by the Wallowa Mountains Office of the Wallowa-Whitman National Forest approximately ten air miles southeast of the town of Joseph, Oregon. Within the project area 20 commercial thinning units have been identified for restoration covering 877 acres, or four and half percent of the overall project area. In 1989 the Canal Fire burned just over 12,000 acres in the project area of which nearly 40 percent was characterized as a high severity stand replacing disturbance event. Across the Blue Mountains forest health has been in a steady decline for over a century due to a number of factors that can directly and indirectly be correlated to the aggressive suppression of naturally occurring wildfires. Historically, wildfire in the Blue Mountains kept forested systems in a state of ecological equilibrium with generally low intensity and low severity surface fires which naturally thinned out understory layers of shade tolerant species that if left unchecked can contribute to high intensity and high severity stand replacing fires. The absence of these low severity disturbance events, stand densities increase and the species composition shifts to a higher proportion of shade tolerant species. Once stand densities surpass upper management levels (75 percent of full stocking) and approach their maximum stocking levels for a given management species, site available resources become limited, suppression mortality becomes prevalent, stand growth stagnates, and the stand s overall health declined leading to a greater susceptibility to disease and insect infestation. When densities approach their maximums they lose their ability to resist both biological and physical disturbance, and their resiliency to these disturbance events declines markedly. Under this successional scenario both ecological and anthropogenic values have a greater probability of being lost in a catastrophic disturbance event. Each incremental disturbance compounds this risk primarily by adding hazardous fuels through both overstory tree mortality and the 1

2 prolific regeneration of shade tolerant species in the understory which create a vertical fuel ladder for surface fires to move into stand canopies. Management Direction Forest Plan Direction The 1990 Forest Plan (FP) for the WWNF, as amended, provides guidance through its established goals, objectives, desired future conditions, forest-wide standards and guidelines, and specific management area (MA) direction (USFS 1990). Forest Wide Standards and Guidelines The Forest Plan states the goals for the timber resources 1) to provide for the production of wood fiber to satisfy National needs and benefit local economies consistent with multiple resource objectives, environmental constraints and economic efficiency. 2) to provide fuelwood for personal and commercial uses. (FP 4-48) The Forest Plan states the goal for Insects and Disease is to control Forest pests to levels that are compatible with resource objectives. (FP 4-55) The Forest Plan states the goal for fuelwood as to provide fuelwood of all species as a renewable energy resource for personal and commercial uses. Management Direction Specific to Individual Management Areas The Forest Plan, pages 4-56 to 4-98; the descriptions provide specific multiple use direction to help reach management goals and objectives. Each existing management area is set forth as 1) a description which defines specific management area goals, objectives, and resource priorities, and 2) management areas in the Cold Canal project map 1. Management Area 1, (MA 1) Timber Production Emphasis The management goals for MA-1 are to emphasize wood fiber production on suitable timber lands providing relatively high levels of forage and recreation opportunities. Temporary forage increases result from silvicultural activities (FP 4-56). Wildlife. Maintain at least 30 percent of the forest land within a project area as cover, including marginal and satisfactory cover. Timber. Use timber management to convert unmanaged natural stands to vigorous managed stands Insects and Diseases. Prevent and/or suppress insects and diseases using integrated pest management techniques when outbreaks threaten resource management objectives. Activities might include stump treatment for root rots, 2

3 application of pesticides for defoliators and cone insects, early harvest, stocking control and species control. Management Area 3, (MA 3): Wildlife/Timber This management area provides a broad array of Forest uses and outputs with emphasis on timber production. However, timber management is designed to provide nearoptimum cover and forage conditions on big game winter ranges and selected summer ranges. (FP 4-60) Timber management will be similar to that of Management Area 1 but constrained to meet wildlife objectives Management Area 15 (MA 15): Old-Growth Preservation These areas are intended to maintain habitat diversity, preserve aesthetic values and to provide old-growth habitat for wildlife. Old-growth stands contain mature and over mature trees in the overstory and are well into the mature growth stage and usually contain a multi-layered canopy and trees of several age classes. Timber. Areas allocated to old-growth timber will have no scheduled timber harvest although salvage may occur following catastrophic destruction if a more suitable stand exists. Insects and Disease. Control of pests is encouraged where pests threaten destruction of an old growth stand. Where destruction of the old-growth is not likely, artificial control of pests will occur only when this can be accomplished without adverse effects on old-growth values. Management Area 6, (MA 6): Back Country This management area provides opportunities for dispersed recreation activities in areas undeveloped outside of wilderness. (FP 4-60) Timber management is allowed in the event of catastrophic tree mortality, to maintain or improve recreational or visual characteristics, or to prevent the spread of insects onto adjacent lands. Project treatments will only be occurring in the timber production (MA1) management areas. Fuels reduction thinning will occur within management areas MA1 and Old- Growth (MA15). There will be approximately 74 acres of MA15 treated by only treating non-commercial material smaller than 6 DBH. This will result in less competition for larger residual trees and improve the health and vigor of the stand while decreasing ladder fuels. The natural fuels units (prescribed fire) are in management areas MA1, MA15, and MA6. Existing Condition Since the Canal Fire in 1989, this area has grown back as dense stands of lodgepole 3

4 pine, interspersed with Western larch, Douglas-fir, and ponderosa pine. Fuel levels and stand densities are high, placing the natural resources in the area at high risk from wildfire impacts again. Fire suppression and historic logging practices have shifted sites dominated by early seral species of western larch, ponderosa pine, and Douglasfir to later seral species of grand fir and Engelmann spruce. The ponderosa pine and mixed conifer stands in this area have also grown in with trees and vegetation. The dense re-growth of lodgepole pine after the fire, and the dense conditions in adjacent stands, leave the area at high risk from impacts from wildfire, insects, and diseases. Collectively past management, to largely include fire suppression, historic logging, and grazing, has manipulated the stand structure and species composition in a way that has in turn changed ecological processes. High grade logging of the largest most valuable trees has left a deficiency across the planning area, and across many of the forests of the intermountain west, of large and long-lived fire resistant early seral species like Ponderosa pine and western larch. Decades of this type of forest management along with aggressive fire suppression has created stand conditions with an abnormal proportion of early seral species and a coinciding abnormal accumulation of hazardous forest fuels. These conditions in turn alter ecological processes like fire behavior as previously described, but also, as densities increase and stand canopies close, competition for site available resources becomes intense. Competition for these resources (light, water, nutrients) leads to suppression mortality, reduced vigor, and a greater vulnerability to destructive insects, disease, and parasitic plants. Although all the damaging biological agents that are currently found in the planning area stands are endemic, abnormally high stand densities can create conditions for epidemic levels of these types of disturbance. The reduction of light penetrating to the forest floor in many of these stands has created an understory devoid of forb and shrub species important for wildlife forage. The potential vegetation groups (PVG) of these selected stands as defined by Powell 2007, and determined through inventory of the project area are represented as follows: 63 percent Upland Forest, 28 percent Dry Upland Forest, and 9 percent Cold Upland Forest. Structurally, 65 percent of the stands are classified as being in the understory reinitiation stage of development, 24 percent in Old Forest Multi-storied stage of development and 11 percent is considered to be in both of these stages. Table 1 below summarizes the more relevant current stand metrics and conditions of the proposed commercial units in the Cold Canal Project Area. 4

5 Table 1: Cold Canal Harvest Units Current Stand Conditions Stocking level species Unit Acres PVG Plant Association Structural Stage QMD TPA >5" SDI BA/Ac >5" UMZ BA/Ac LMZ BA/Ac UF ABGR/BRVU UR DF 3 40 UF ABLA/VAME OFMS DF UF ABGR/LIBO3 UR PP 5 41 Dry UF ABGR/CARU UR PP 6 53 Dry UF PSME/CARU UR PP 7 4 UF ABLA/LIBO3 OFMS DF 8 52 UF ABGR/BRVU UR DF 9 27 UF ABGR/LIBO3 OFMS/UR DF Cold UF ABLA/VASC/POPU3 OFMS WL Dry UF ABGR/CARU OFMS PP Dry UF PSME/CARU OFMS PP UF ABGR/BRVU UR DF UF ABGR/BRVU OFMS/UR DF UF ABGR/BRVU UR DF Dry UF ABGR/CARU UR PP UF ABGR/VAME UR LPP 27 6 UF ABLA/LIBO3 OFMS/UR WL Dry UF ABGR/CARU UR PP Cold UF ABLA/VASC/POPU3 OFMS WL UF ABGR/BRVU UR DF 5

6 Desired Condition Although there are multiple objectives driving this project in accordance with the Multiple Use and Sustained Yield Act of 1960, the primary objects are to restore stand structure and composition within the historical range of variability (HRV). Restoring the structure and composition of these stands will significantly reduce surface and aerial fuel loading, which is a strong driver of stand replacing crown fires. For all treatments the object structurally is to move these stands towards an Old Forest Single Storied structure which represents the greatest resiliency to disturbance, particularly catastrophic wildfire, by promoting a structure, composition and density typical of early seral stands. When considering the projected effects of climate change including increases in average temperature, declining mountain snowpack, milder winters, prolonged summertime droughts and a correlating heightened susceptibility for epidemic insect infestations; the current conditions of these identified stands are not sustainable and warrant immediate management action. To address these forest health concerns in the Cold Canal Project Area, stands were selected for treatment based on their current stocking level, departure from HRV, fuel loading, proximity to the wildland urban interface, and operational efficacy based largely on topography and existing road infrastructure. Stands selected for commercial treatment within the project area are largely characterized as mature mixed conifer stands that are all stocked beyond their respective lower management zones based on series and plant association (Powell, 1999). The majority of the stands planned for treatment are currently stocked beyond their associated upper management levels. A HRV analysis was completed for tree density, species composition, and structural stage generally corroborates the position that these stands are overstocked and appropriate for a silvicultural treatment (see appendix HRV Analysis). The stands that have been identified for commercial thinning are all considered over-stocked with densities approaching or beyond the upper management zones for their respective tree species series and plant association. All the prescriptions designed for this project are thin from below treatments favoring fire resistant early seral species. Trees selected for removals under a thin from below prescription are generally suppressed, intermediate and some co-dominant trees that are considered undesirable because they are either a shade tolerant species or exhibit indicators of disease or insect infestation. The largest, healthiest, and most vigorous trees are selected for retention based on species and qualitative phenotypes like form and live crown ratio. To foster the greatest resistance and resiliency to disturbance events, mixed conifer stands are recommended to be managed by using the stocking level curves for the single species prescribing the fewest trees per acre (Chochran et al. 1994). Additionally, in accordance with the 1995 PACFISH (Eastside Screens) all 6

7 trees greater than 21 dbh regardless of species or evidence of disease, insect or parasitic plants (i.e. dwarf mistletoe) will be retained. This proposal is needed because there is a gap between the current conditions and the desired conditions within the project area. Within this area, the Forest Service recognizes a need for: Safer Wildland Urban Interface (WUI): The portion of Cold Canal that is within the Divide Camp and Little Sheep WUI areas would have fuel loadings, arrangement, and continuity that would support direct attack suppression efforts by firefighting personnel during a wildfire situation and reduce risk of fire spreading through the canopy and transitioning from the ground into the canopy (ground to crown fire). Resilient forests: At the landscape scale, the Cold Canal project area would have increased resiliency to natural disturbances. Reduced stand densities would improve forest health, and reduce the risk of loss to uncharacteristic occurrences of insect, disease, and wildfire. Direct and Indirect Effects of Alternative A on Forest Vegetation Past actions and fires would continue to affect the analysis area under Alternative A. The Canal Fire of 1989 converted much of the Cold Canal planning area to stand initiation structural stage (a new stand of young trees). Fire frequencies and intensities plus insects and diseases have had a major influence on species composition, stand densities, vertical stand structure and distribution of the vegetation in the Cold Canal planning area. In addition, human influence has altered the vegetation through fire exclusion, domestic livestock grazing, agricultural practices and vegetation management practices like timber harvesting, precommercial thinning and reforestation activities. In turn, this altered vegetation has modified the effects of some natural processes like wildfire, insect levels and plant pathogens, creating more extreme effects such as increased duration and intensities of insect outbreaks over historic levels (USFS 1995). Under the No Action alternative, stand structures that are over represented on this landscape (stand initiation, understory regeneration, and old forest multi stratum) would not be treated and would not develop more rapidly into stands having sufficient numbers of large trees with resilient stand structures. Under this alternative, existing management would remain unchanged. These stands would remain at high densities, with competition for resources and sunlight, until they began to self-thin the intermediate and overtopped trees. The shade tolerant species 7

8 such as grand fir would continue to grow in the understory, competing with the more insect and fire resilient early seral species such as ponderosa pine and western larch. No action would result in competition related mortality, minimal tree growth, smaller crown ratios with restriction on branch growth, and overall slower stand development. The forested stands are expected to continue to show evidence of increased insect activity, including mortality, and could reduce the already low numbers of early seral species. If a high severity wildfire occurred, large portions of the planning area could be reset to stand initiation stage and alter the species cover type. Current stand dynamic processes could be expected to continue until a disturbance of insect, disease or fire alters forested stand conditions. Thinning from below and crown release treatments in old forest would not occur. As a result, competition induced mortality would continue and increase as more shade tolerant trees become established and grow in the understory. Under-represented old forest single story stands would continue to decline as additional trees grow in the understory and over time, become converted into additional, already over represented old forest multi story stands (O Hara 1996). In addition, these remaining old forest stands would continue being at high risk of loss to insects, disease and wildfire. This risk would continue to increase over time. Stand improvement thinning would not occur on acres of post-burn stand initiation within the planning area. In these overly dense stands the growth rates would continue to decrease as the stands fill in beyond the site capacity. Once all the available growing space is filled, competition based mortality would accelerate, increasing fuel loading as additional dead trees fall to the ground. These stands would eventually convert to a stem exclusion stage with low site productivity and a single species, lodgepole pine, which would leave these stands at an even higher risk of loss to uncharacteristic fire, insects and disease (Powell 1999). Under the No Action alternative conifers would continue to encroach into aspen stands, which play a unique role on the landscape. These stands would not be treated to create conditions where fire can be used to remove other competing vegetation and material that would allow for more sprouting and promote regeneration of these stands. Periodic disturbance is necessary to maintain clone vigor (Long and Mock 2011). Quaking aspen would therefore continue to decline under this alternative, resulting in the loss of valuable wildlife habitat and the loss of this species within the planning area until a sufficient disturbance occurs to encourage sprouting. Stand densities may eventually decline under the No Action Alternative through competition- induced mortality. Stands would continue to be susceptible to disturbances due to both density related stress between trees competing for limited 8

9 resources and from stand structures having ladder fuels of smaller trees in dense stands. In addition to slow stand development, these stands would continue to be at higher risk for stand replacement fires. The risk of stand replacement fires can be reduced through reducing surface and ladder fuels, increasing live crown height, decrease crown density, while retaining the largest trees (Agee, 2002). Direct and Indirect Effects of Alternative B on Forest Vegetation Due to the limited options for treatment across the landscape, proposed treatments are not expected to result in measurable differences in stand structure or species composition on a landscape scale. However the individual stands that are treated are generally expected to move more rapidly toward stand conditions expected within the HRV, from younger, denser stands toward late and old single story conditions. Treatments are expected to sustain the early seral, large trees (ponderosa pine) that are not as well represented on the landscape. There may be opportunities for the early seral species to regenerate in the more open and disturbed areas. This activity would decrease the stand density, while also reducing the late seral species (grand fir) that compete with the early seral species. The proposed treatments would remove components within the understory, decreasing ladder fuels. Treatments in these stands would lead to a more sustainable and resilient forested structure after completion. Treatments under Alternative B would be intended to reduce stand densities, and would focus on retaining more fire-adapted, early-seral species (ponderosa pine, and western larch), and reducing the percent of late-seral species (grand fir). These changes would be expected to improve stand resilience and reduce the risk of impacts from insects, disease and wildfire. Under Alternative B, stand improvement activities would be expected to improve remaining trees health, vigor, and resistance to mountain pine beetle (Christiansen et al. 1987, Franceschi et al. 2005, Kolb et al. 1998, Shrimpton 1978). Reducing stand density, particularly by separating tree crowns, and reducing canopy layering, also reduces overall susceptibility to defoliating insects such as the Douglas-fir tussock moth and western spruce budworm (Schmitt and Powell 2005). Prescribed burning would result in a reduction of late seral species such as grand fir would be reduced in the understory because of their lack of fire resistance. Over the long term, with maintenance burns this could lead to a higher representation of early seral species in the midcanopy and understory. Small gaps where regeneration would be promoted may be created in area where spot torching occurs, but these would be small and relatively rare. These treatments would promote species and structural diversity in the planning area (Youngblood 2006). As fire burns through timbered areas, the trees in the understory with thinner bark and that are less fire tolerant, usually the late seral species, will have the greatest mortality. 9

10 In three units where quaking aspen trees exist, treatments would enhance and stimulate aspen stands by removing conifer trees less than 21 inches in diameter in and near the aspen clone area. Some aspen may be cut or burned which stimulates growth in aspen. Fencing stands to keep livestock, elk and deer out would prevent foraging of suckers allowing them to reach maturity. Direct and Indirect Effects of Alternative C on Forest Vegetation As in Alternative B, the effects on stand structural stage are very small but do move the area slightly toward historic range. An additional unit would be commercially thinned resulting in, reduced overstory stand density, higher overstory tree vigor and increased insect and disease resistance in this unit. In Alternative C, this stand improvement thinning would not occur in 13 units (approximately 2,909 acres). There would be less of a change in Alternative C than in Alternative B in terms of tree density due to this lack of tree improvement thinning. The health, vigor, resistance to mountain pine beetle would not be enhanced or promoted in these stands (Oliver and Larson, 1990). Mechanical thinning would not occur and these areas would continue on their current trajectory of stagnation with low growth rates and low species diversity. Understory recruitment would remain low to non-existent. The direct and indirect effects of the Cold Canal treatments in Alternative C are similar to those described in Alternative B with the main difference relating to acreage. Cumulative Effects of Alternatives A, B, and C on Forest Vegetation As in Alternative A, past actions, fires, and insects and disease have affected the vegetation in the Cold Canal planning area and modified the effects of some natural processes like wildfire, insect levels and plant pathogens, creating more extreme effects such as increased duration and intensities of insect outbreaks over historic levels (USFS 1995). The action alternatives (B and C) would help move the treated stands toward historic stand structures, lower stand density, and increased early-seral species composition. Commercial thinning in the understory reinitiation and old forest multi-strata structural stands would move these stands toward currently under represented structural stages, creating landscape diversity in the project area. With the exception of fire suppression most of the ongoing activities in the analysis area do not affect the old forest, stand density, and species composition to any measurable degree within the planning area. Fire suppression can postpone wildfire disturbances until effective hazardous fuel reduction treatments can be implemented. The treatments proposed in this project are intended to increase the resiliency of treated stands to the effects of moisture stress, insects, disease and wildfire. As a result, the proposed treatments are expected to increase the resiliency of treated stands to the projected effects of climate change in the planning area. 10

11 HRV Analysis for Forest Structural Stages: A HRV analysis was completed for forest structural stages of the forest vegetation affected environment. Because forest structure varies by biophysical environment, the HRV analysis was stratified by potential vegetation group. Forest structural stage HRV results are represented in Table 1. Table 1 Structural Stages HRV Cold Upland Forest Upland Forest Dry Upland Forest Historical Historical Historical Range Current Range Current Range Current Percentage Percentage Percentage Percentage Percentage Percentage Sources/Notes: Gray shading indicates structural stages that are above or below the historical range of variability. Historical ranges were derived from Powell (2012). The data used in these figures came from the FSveg- Sp R06 Extract Vegetation Polygons RSW stand data layer in GIS Big Sheep Stand Exam Data and photo interpretation. Table 1 above shows that the stand initiation stage is well above historic ranges in the cold and moist upland forest. The stand initiation stage occurs predominately where the Canal Fire occurred. The stem exclusion and old forest single stratum are both below the historic ranges for the area. Some of the stem exclusion and old forest single stratum stages may have been converted to the stand initiation stage due to the occurrence of stand replacing fires. The understory reinitiation and old forest multi strata are either within or above the historic ranges for the structural stages. The abundance of UR and OFMS is due to the ingrowth of a second cohort of late seral shade tolerant tree species. Forest Vegetation Species Composition: Table 2 summarizes the existing vegetation cover types for the forested vegetation within the project area. The project is dominated by three species; two of the species are mid-seral and late seral species Douglas-fir and grand fir. The concept of seral species here is probably best described in terms of tolerance, to shade, fire, drought, and the relative ability of a species to regenerate and establish new plants, and survive in a forested environment For example, ponderosa pine and western larch are very intolerant to shading. These species simply do not thrive if the crowns are shaded. Grand fir on the other hand is very tolerant to shade, but can also thrive in full sunlight. Douglas-fir is considered to intermediate in shade tolerance.

12 Conversely, grand fir is generally intolerant of repeated fire, whereas, ponderosa pine and western larch are much more tolerant of fire. Again Douglas-fir is intermediate in tolerance to fire. Other than lodgepole pine regeneration the planning area is lacking in early seral species such as ponderosa pine and western larch. The current dominant species are more susceptible to insects and diseases than the historically dominant species. The data used in these figures came from the FSveg-Sp R06 Extract Vegetation Polygons RSW stand data layer in GIS Big Sheep Stand Exam Data and photo interpretation. Table 2 Vegetation Cover Types Vegetation Cover Type Acres of Forested Ground Percentage in PAB Ponderosa pine Douglas-fir Western Larch 0 0 Lodgepole pine Grand fir Subalpine fir and Spruce Broadleaved trees (Aspen) 21.4 <1 Map 1 shows the locations of the vegetation cover types. The map shows the dominance of lodgepole pine in the Canal burn area in the western half of the planning area. It also shows the dominance of the late seral species grand fir and Douglas-fir in the areas that did not burn in the Canal Fire.

13 Map 1 Species Composition

14 HRV analysis for species composition: An HRV analysis was completed for the species composition (vegetation cover) for the project area. The species composition analysis below is a way to look at the landscape and determine if it is out of balance. The vegetation cover was stratified by the potential vegetation groups. The results of this are in table 3. Table 3 Vegetation Cover Type by PVG Vegetation Cover Type Cold Upland Forest Upland Forest Dry Upland Forest Historic Range Percentage Current Percentage Historic Range Percentage Current Percentage Historic Range Percentage Current Percentage Ponderosa pine Douglas-fir Western Larch Lodgepole pine Grand fir Subalpine fir and Spruce Broadleaved trees (Aspen) Grass-Forb Shrub Sources/Notes: Gray shading indicates species compositions that are either above or below the historical range of variability. Historical ranges were adapted by Powell (2012). Current percentage data used in these figures came from the FSveg-Sp R06 Extract Vegetation Polygons RSW stand data layer in GIS Big Sheep Stand Exam Data and photo interpretation. Table 3 above shows that each potential vegetation group has higher amounts of lodgepole pine than the historic range. The cold upland forest has less subalpine fir and spruce when compared to the historic ranges. The moist upland forest has an abundance of late seral species such as grand fir. The moist upland forest also has less Douglas-fir when compared to historic ranges. The dry upland forest has less early seral species such as ponderosa pine and western larch, however it has copious amounts of mid and late seral species such as grand fir and Douglas fir than the historic ranges. This suggests that the dry and moist upland forest have more late seral species than prior to wildfire suppression. This indicates that forested conditions are likely outside the sustainable range. Stand Density Table 4 summarizes the existing tree density classes for the forested acres of the Cold Canal planning area. It shows that the majority of the planning area is in the high and moderate

15 classes (60%) while the remaining 40% of the planning area is in the low density class. The data used in these figures came from the FSveg-Sp R06 Extract Vegetation Polygons RSW stand data layer in GIS. Table 4 Densities Tree Density Acres Percent of Total Low Moderate High HRV Analysis for Tree Density: An HRV analysis was completed for tree density classes of the forest vegetation affected environment. Because tree density varies by potential vegetation group, the HRV analysis was stratified by potential vegetation groups. The tree density HRV results are presented in table 5. Table 5 Densities for each PVG Tree Density Class (Basal Area, in square feet/acre at 10inch QMD) Range of Variation (Percentage of Area) Current Percentages in PAB Cold Cold Dry Dry UF Cold UF Dry UF PVG UF UF UF UF UF UF Low <70 <90 < Moderate High >110 >135 > Sources/Notes: Gray shading indicates tree density classes that are above or below the historical range of variability. Historical ranges taken from Powell (2012). The data used in these figures came from the FSveg-Sp R06 Extract Vegetation Polygons RSW stand data layer in GIS and Big Sheep Stand Exam Data. The table above (Table 5) gives a depiction of the target levels for basal area for each level of density and the percent of landscape area in percentage for each level of density. For example, in the low density class, the cold upland forest type shows that percent of the land should have a basal area of 70 or less. The high density class is above or within historic ranges of all three PVG s. This analysis suggests that the dry upland forest PVG portion of the affected environment has too little of the low density class and too much of the high density condition. In addition, the cold upland forest areas in the planning area have too little of the moderate density condition and too much of the high density condition. In the moist upland forest portions of the planning area there is not enough moderate density condition and the high density condition is at the high end of the range of variation. This indicates that there is an opportunity to use silviculture methods to move densities toward historic ranges.