SOIL ANALYSIS. for. Rancheria Forest Restoration Project Kern River Ranger District Sequoia National Forest Kern County, California.

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1 SOIL ANALYSIS for Kern River Ranger District Sequoia National Forest Kern County, California April 2013 Prepared/Approved by Fletcher Linton DATE 7/5/2013 Fletcher Linton Forest Botanist Sequoia National Forest

2 April 2013 Introduction The Sequoia National Forest, Kern River Ranger District is proposing the Rancheria Forest Restoration Project to provide ecological restoration and restore resilience to 5,879 acres of National Forest System lands near Alta Sierra in the Greenhorn Mountains of the southern Sierra Nevada. The project area is approximately six air miles west of Isabella Lake, Kern County, California, in Townships 25, 26, and 27 South and Ranges 31 and 32 East, Mount Diablo Base and Meridian. The as proposed is located primarily along the ridgeline of the Greenhorn Mountains adjacent to Rancheria Road from Shirley Peak to Davis Flat. The project area includes both general second-growth forest areas and pine plantations, with several hundred acres of chaparral. The proposed action would use a combination of commercial timber harvest, hand thinning, and prescribed fire/wildfire utilized for integrated objectives of ecological restoration. Thinned trees, hazard trees, and other vegetation found to be in excess of fuels and forest health needs would be utilized under a timber sale or other forest product contract. In addition to the proposed action, the Forest Service also evaluated the following alternatives: Under the No Action alternative (Alternative 1), no change from the current management direction or level of management intensity would take place. No fuels treatment, tree thinning/removal, or ecological restoration would be implemented. In Alternative 3, the Kern River Ranger District of the Sequoia National Forest proposes to treat 5,879 acres using a combination of hand thinning, and prescribed fire/wildfire utilized for integrated objectives. No mechanical treatment would be used. The Rancheria analysis area includes 5,879 acres of National Forest System (NFS) lands near Alta Sierra in the Greenhorn Mountains, entirely within Kern County. Elevations within the compartment range from approximately 5,050 feet on the south end at Greenhorn Creek to near 6,615 feet in the North end of the project area, near Shirley peak. Soils in the project are derived from moderately weathered granitic plutons, with some small meta-sedimentary and gabbro inclusions. Vegetation types within the project include mixed conifer pine and fir forest. These second-growth forests within the Rancheria project area are now overstocked with middle-aged trees and dominated by shade-tolerant white fir (Abies concolor) and incense cedar (Libocedrus decurrens). Although they are native to the area, this species composition is less resilient and less adapted to fire than the pine (Pinus ponderosa, P. lambertiana) and black oak (Quercus kelloggii) dominated forest ecosystem historically found in the area ( Oak Ridge runs through the middle of the Project). Soil Quality Standards Forest soil quality standards are taken from the 1988 Sequoia National Forest Plan, the 1990 Mediated Settlement Agreement, and the Sierra Nevada Framework (2001, 2004). The Forest soil quality objectives are tiered to, and are consistent with, Region 5 standards and guidelines. Soil loss should not exceed the average rate of soil formation.

3 Maintaining sufficient soil cover to prevent accelerated soil erosion. Use the California Soil Survey Committee Soil Erosion Hazard Rating to determine the kind, amount, and distribution of soil cover needed. Soil porosity should be at least 90% of its natural condition. A 10 percent reduction in porosity corresponds to a threshold bulk density that indicates detrimental compaction. Maintain soil organic matter in at least 85% of its original state in the upper 12 inches, and maintain at least 50% ground cover in litter and duff. Proposed Activities The two types of treatment types of concern for TES plants would be Restoration Thinning and Plantation Thinning. These treatments involve the use of mechanical equipment which has the potential to cause moderate to heavy soil disturbance. The mechanical Restoration Thinning prescription would apply to 842 acres of natural stands of second-growth conifer of mixed species and age classes. Mechanical Plantation Thinning would occur or 260 acres of existing pine plantations. All other treatments (hand thinning, and prescribed fire/wildfire) are of no concern for TES plant effects because they would be accomplished with hand tools resulting in low potential to cause moderate to heavy soil disturbance. In addition to the proposed action, the Forest Service also evaluated the following alternatives: Under the No Action alternative, no change from the current management direction or level of management intensity would take place. No fuels treatment, tree thinning/removal, or ecological restoration would be implemented. In Alternative 3 the Kern River Ranger District of the Sequoia National Forest proposes to treat 5,879 acres using a combination of hand thinning, and prescribed fire/wildfire utilized for integrated objectives. No mechanical treatment would be used. Background Except for Evans flat and Evans meadow, soils in the Rancheria Project area of the Kern River Ranger District area are developed from solid bedrock. The bedrock in this area is predominately a mix of four different granitic and granodiorite plutons of Cretaceous and late Cretaceous age. There are two small inclusions of Cretaceous Gabbro and Mesozoic meta-sedimentary rocks. This project is primarily within the higher elevation area of the southern Greenhorn Mountains. The relief consists of flat to moderate ridge tops and top-slopes to steep mid-slopes broken by small drainages and basins. The soil textures across the project are mostly loams and sandy loams which, in general, are resistant to mechanical compaction. The specific soil associations high erosion potential within the Rancheria Forest Health Restoration Project area are shown in the table below. The soil associations are shown with their percent in the project area, erosion hazard rating (EHR), predominant soil texture, and slope range. A high rating means accelerated erosion can occur, and the need for erosion control measures should be evaluated.

4 Soil Associations with High Erosion Hazard within the Project Area Soil Association Shaver Chaix Dome association Holland--Shaver association % Project area* 25% 15% Erosion Hazard Rating (EHR) High High Soil Texture sandy loam sandy loam, fine sandy loam Slopes % % A little more than a third of the soil associations within the treatment areas have high EHRs. Small inclusions of other soils total less than 20% (by area) within these soil associations. Inclusions within these tend to have similar characteristics as the association they occur with, but some of the EHRs can be lower than given above. The maximum EHRs are based on little or no vegetative cover present and on the long-term average occurrence of 2-year, 6-hour storm events. These ratings and their definitions are taken from the Sequoia National Forest Order 3 Soil Survey (USDA et al., 1996). Slope is the major overriding factor that determines a soil map unit s EHR. A particular soil-type complex with steeper slopes will have higher EHRs than the same soil-type complex on gentler slopes. On soil associations with high EHRs, accelerated erosion will occur in most years. Adverse effects on soil productivity and nearby water quality are likely to occur, especially during periods of above average storm occurrence. During management activities, erosion control considerations/mitigations are necessary in these areas to prevent accelerated erosion. A majority of the mechanical units are located in Shaver Chaix Dome association soils found in the central portion of the project area on the eastern side Oak ridge (the Greenhorn mountain crest). Elevations here range from 5,800 to 6,800 feet. This soil family is formed from residuum derived from granitic bedrock. All of the areas given a high EHR by the soil survey have slope ratings from 30 to 50 %. The Holland--Shaver association is also formed in residuum derived from granitic bedrock. This soil is found in the lower elevation south-eastern portions of the project area outside of all but one of the mechanical units. The soil association of most concern from mechanical restoration thinning is the Shaver Chaix Dome association. This soil is proposed ground-based mechanical treatments in Units 9, 11, 13, 14, 15, 16, 20, 21, 22, 23, 38, and 44. Mechanical yarding on this soil type could potentially cause moderate to high soil disturbance and subsequent soil erosion. As such, units within this soil type were targeted for pre-project soil quality evaluation. Surveys Both soil associations within the project area with high EHRs were field verified in multiple locations by a Forest Service soil scientist and silviculturist. The ground-based mechanical harvest layouts were also assessed and confirmed as well. Each of these soil associations were evaluated in the field for consistency with the soil survey. Both were found to be in agreement with the soil survey. The soil association of most concern (Shaver Chaix Dome association) was sampled for soil quality attributes in three locations proposed for ground based yarding. Some of the attributes measured were: the amount of soil organic cover; large woody debris; past erosion; and past disturbance. Existing disturbance, from past timber sales, was mostly light, while soil organic cover and large woody debris density greatly exceed the minimums for preserving soil productivity. Past erosion was minimal as well.

5 Analysis/Conclusion Both soil associations/families with high EHRs in the project area are not textures particularly susceptible to compaction, and soil organic cover is sufficient to minimize compaction effects throughout the project area. Additionally, mechanical disturbance will be limited to a small numbers of passes in any one area, because of treatment layout. Therefore, preventing these soils from compacting should not be difficult, and detrimental compaction will not be a problem. Within the Rancheria Forest Health Restoration Project area, most of the trees selected for treatments are solitary or small group selections. This will limit off-road yarding to a small number of passes in any one area. Also, on slopes greater that 35% (which includes half of the areas with high soil erosion potential) most of the yarding will be done in single passes. Existing soil organic cover and large woody debris densities greatly exceed the minimums for preserving soil productivity. Mechanical soil disturbance will be limited by low numbers of passes. All these factors will insure that mechanical soil disturbance will be light and that soil organic cover will be preserved. The implementation of best management practices (Appendix A) and treatment layout described above will make it possible to implement this project while conserving soil organic cover and minimizing soil disturbance, thus preventing accelerated erosion and detrimental compaction. As such, the Rancheria Forest Health Restoration Project will be consistent with soil conservation and productivity guidelines. Prepared by Fletcher Linton, Soil Scientist, Sequoia National Forest. References Sequoia National Forest 1988 Land and Resource Management Plan Sequoia National Forest 1990 Land Management plan and Mediated Settlement Agreement USDA Forest Service 2001/2004 Region 5, Sierra Nevada Framework Plan Amendment and Revision. USDA et al Sequoia National Forest Soil Survey

6 APPENDIX A Summary of Regional BMP s relevant to Conserving Soil Productivity Best Management Practices (BMP s) protect water quality, primarily by reducing unnatural erosion. These practices are enforced by the State Water Quality Board to implement Sate and Federal Clean Water Laws. The BMP s that will be part of this projects design also serve to implement soil quality standards to protect soil quality. Best management practice 1-3 is determination of surface erosion hazard for timber harvest unit design. The objective is to identify high erosion hazard areas in order to adjust treatment measures to prevent downstream water quality degradation. This is a preventive practice based on the California Soil Survey Committee erosion hazard rating. On site evaluation determines the need for erosion control measures. Best management practice 1-5 is limiting the operating period of timber sale activities. The objective is to ensure the purchasers conduct their operations including erosion control work, in a timely manner. Contract provision C6.3 must be in all timber sale contracts. This provision requires a plan of operations, including erosion work and slash treatment. Contract clause B6.31 requires the purchaser to provide an annual schedule of activities, including erosion control. Contract clause C6.313 limits the purchaser s operating period to periods when adverse environmental effects are not likely. Contact provision B6.6 can be used to close down operations under adverse operating conditions to protect resources. Best management practice 5-2 is slope limitations for mechanical equipment. The objective is to reduce erosion and sedimentation. This is a preventative measure to limit surface disturbance and keep surface water from concentrating.