SECTION 3.3 SOILSa123.g.akamai.net/7/123/11558/abc123/forestservic... · Section 3.3 – Soils 3-98 SECTION 3.3 SOILS_____ I. INTRODUCTION Vegetation management activities that can

Section 3.3 – Soils 3-98

SECTION 3.3

SOILS____________________________________

I. INTRODUCTION Vegetation management activities that can effect soil quality and productivity, and create detrimental soil conditions were identified as issues of concern during project scoping. This analysis describes the existing condition of the soil resource within the BCLMP area, and evaluates potential direct, indirect, and cumulative effects of three action alternatives and a no action alternative to soil quality and soil productivity within activity units. A. OVERVIEW Soil Quality Forest Service Manual (FSM) 2550 defines soil quality as:

The capacity of a specific kind of soil to function, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation and ecosystem health. There are two aspects of the definition: inherent soil quality and dynamic soil quality. Inherent Soil Quality is an aspect of soil quality relating to a soil’s natural composition and properties as influenced by the factors and processes of soil formation, in the absence of human impacts. Dynamic Soil Quality is an aspect of soil quality relating to soil properties that changes as a result of soil use and management or over the human time scale.

Forest Service Manual Section 2550 and the Region 1 Supplement 2500-99-1 provide direction for maintaining soil quality. Soil quality is maintained when erosion, compaction, displacement, rutting, burning, and loss of organic matter are maintained within defined soil quality standards. Region 1 guidelines state that detrimental soil disturbance should be limited to 15% or less of the activity area, not including system roads. While detrimental soil disturbances are the basis for the effects analysis, not all soil disturbances have a detrimental effect on soil productivity. Several factors that influence soil quality are described below, including soil productivity (physical soil characteristics, organic matter and nutrients, soil organisms), soil erosion, and mass wasting / soil stability.


Soil Productivity FSM 2550 defines soil productivity as:

The inherent capacity of the soil resource to support appropriate site-specific biological resource management objectives, which includes the growth of specified plants, plant communities, or a sequence of plant communities to support multiple land uses.

Characteristics that influence soil productivity include physical soil characteristics, organic matter and soil organisms.

Physical Soil Characteristics

Soil properties and forest productivity can be affected by heavy equipment used for harvest and site preparation but these impacts vary greatly with site conditions and operational practices (Ares et al., 2005). The physical characteristics of concern are soil depth, the amount of pore space in the soil, and the density of the soil. Some commercial timber sale activities and site preparation can compress or compact soils and if soils are wet enough cause rutting and puddling. All of these changes to the physical soil characteristics reduce the amount of pore spaces. This in turn reduces the movement of water and air into and through the soil and impedes root growth through soils, reducing a plant's ability to take up water and nutrients. Compaction and other physical soil disturbances alter the amount of carbon dioxide and oxygen in the soil, affecting both plants and animals that live in or on the soil.

Organic Matter and Nutrients

Organic matter in its various forms contributes to soil productivity. Humus is decomposed organic matter. Duff and litter consist of fresh or partially decomposed leaves, needles, and twigs that are still recognizable on the surface of soils. Large woody debris consists of woody stems greater than three inches in diameter (Harvey, et al. 1994, p.10). Decomposed large woody debris supplies moisture to plants after the soils dry out. All organic matter provides water and nutrients for soil organisms and plants, though the contribution of nutrients from large woody debris, in some forests, is relatively minor (Prescott and Laiho, 2002, p. 390).

Soil Organisms

Soil organisms, including fungi and bacteria, drive nutrient cycling by decomposing organic matter, which releases nutrients for plant growth. Soil organisms depend on organic matter for the nutrients they need to carry out their life processes. Decomposed large woody debris provides important habitat for the survival of mycorrhizae fungi. These fungi form a symbiotic relationship with tree roots, increasing water and nutrient uptake by the trees and the fungi (Perry, et al. 1990, p. 268).

Soil Erosion Soil erosion is the detachment and movement of soil particles by water, wind, ice, or gravity. Erosion occurs when the soil lacks protective vegetative cover. Soil erosion reduces the


productivity of the land by loss of water, soil organic matter, nutrients, biota, and depth of soil (Pimentel and Kounang, 1998). Water is the main cause of soil erosion on steep forested slopes. Erosion is usually minimal on undisturbed forest soils for two reasons: first, abundant organic matter provides a protective blanket on the soil surface that reduces the impacts of raindrops and allows water to move into the soil; second, the surface soil below the organic layer is by its nature porous, allowing water to move rapidly into and through the soil profile. Soil erosion can occur when the surface soil is compacted or when the loose surface soil and its protective layer of organic material are changed by management activities. Compaction, rutting, and puddling reduce the movement of water into the soil and tend to channel and concentrate water. As a result, water runs off (overland flow) and carries soil particles with it. Natural occurrences, such as fire, remove organic matter from the soil surface. When organic matter is removed, soil pores can be plugged by impact from raindrops resulting in overland flow and soil erosion.

Mass Wasting / Soil Stability Mass wasting, also known as mass movement, or slope movement, is the geomorphic process by which soil, regolith, and rock move downslope under the force of gravity. Types of mass wasting includes creep, slides, flows, topples, and falls, each with their own characteristic features, and take place over timescales from seconds to years. Mass wasting can either be natural or man-caused disturbances. Mass failures can result when a sequence of natural events, such as high precipitation or snowmelt, are followed by a trigger such as an earthquake. Some areas are prone to mass wasting because of the nature of the geology or soil. Human disturbances such as roads can cause mass failures if road surface drainage is concentrated enough to saturate soils. Mass failures triggered by human causes are detrimental soil disturbances. These disturbances cause long-term changes in soil productivity that last centuries. B. REGULATORY FRAMEWORK Custer Forest Plan The Forest Plan (USDA 1986) contains Forest-wide management standards in Chapter II (page 25):

• Soil and water resources will be managed to maintain or improve quality of watershed, including soil productivity and water quality. BMP’s will be applied to project activities to assist in meeting or exceeding state water quality standards (see FSH 2509.22).

FSH 2509.22, Soil and Water Conservation Practices, was updated in 1995 (USDA 1995a).

Forest Service Region 1 Guidelines Regional Forest Service guidelines require that National Forest System lands be managed to prevent permanent impairment of land productivity, and maintain or improve soil quality (USDA


1999). Soil quality is maintained when erosion, compaction, displacement, rutting, burning, and loss of organic matter are maintained within defined soil quality standards. Region 1 guidelines state that detrimental soil disturbance should be limited to 15% or less of the activity area, not including system roads. If an area would exceed 15% detrimental disturbance as result of a project, then the project must include actions to mitigate cumulative impacts so the total impact is less than 15%. If the existing condition of an activity area already exceeds 15%, then the project must result in a net improvement in soil condition. While detrimental soil disturbances are the basis for the effects analysis, not all soil disturbances have a detrimental effect on soil productivity.

II. A. INTRODUCTION

AFFECTED ENVIRONMENT FOR SOIL QUALITY

This section describes the major soil types found in the BCLMP area, summarizes field surveys that were conducted to document the existing condition, and discusses the components of the soil quality that could be affected by proposed activities including soil productivity (physical soil characteristics, organic matter and soil organisms), soil erosion, and mass wasting / soil stability. B. SOIL TYPES The NRCS (formerly SCS) mapped the soils of the Ashland RD as part of the Soil Survey of Powder River Area, which was published in June 1971 (USDA SCS, 1971). This information is available at http://www.nris.mt.gov/nrcs/soils/index.asp (main page) with a link to the soil survey, and was used to map soils in the project area. Metadata is available at: http://soildatamart.nrcs.usda.gov/Metadata.aspx?Survey=MT611&UseState=MT For the BCLMP, the Forest Service conducted a GIS analysis to determine the dominant mapped soils in the BCLMP area. Proposed treatment units in the BCLMP area were overlayed by alternative on the digital soils layer. Refer to Appendix A, Maps 28 – 33, which identify treatment codes (Maps 28, 30 and 32) and unit numbers (Maps 29, 31, and 33). Note that the unit numbers were only assigned to commercial treatment units originally proposed under Alternative A. Noncommercial treatment areas were never assigned unit numbers but are still designed on Maps 28, 30, and 32 by prescription code. Table 3.3.1 contains a list of the soil map units in the BCLMP area, which correspond to the soil types shown on the soils maps. The majority of the soils in the BCLMP area is mapped as associations and undifferentiated units. The predominate soil map units in the BCLMP area include the Cabba Association (6,051 acres), Ringling-Cabba Association (3,395 acres), and Campspass-Barvon Association (1,506 acres).

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Table 3.3.1: Soil Map Units in the BCLMP Area1 Map Unit Symbol

Acres Soil Map Unit Name Soil Series Taxonomic Classification

Ca 6,051 Cabba association, 15 to 50 percent slopes

Cabba TYPIC USTORTHENTS, LOAMY, MIXED (CALCAREOUS), FRIGID, SHALLOW

Cb 1,506 Campspass-Barvon association, 15 to 50 percent slopes

Campspass TYPIC EUTROBORALFS, FINE, MONTMORILLONITIC

Barvon ENTIC HAPLOBOROLLS, FINE-LOAMY, MIXED

Ec 16 Elso silt loam, 15 to 45 percent slopes Elso USTIC TORRIORTHENTS, LOAMY, MIXED (CALCAREOUS), FRIGID, SHALLOW El 120 Elso silt loam, 8 to 15 percent slopes

Fe 0 Farland silt loam, 2 to 4 percent slopes Farland TYPIC ARGIBOROLLS, FINE-SILTY, MIXED Fh 5 Farland silt loam, 4 to 8 percent slopes

Fk 139 Farland-Cabba association, 4 to 8 percent slopes

Fl 685 Farland-Cabba association, 8 to 20 percent slopes

Fm 41 Farland-Rockland association, 0 to 6 percent slopes

Fd 1155 Farland and Havrelon soils, 4 to 8 percent slopes

Farland TYPIC ARGIBOROLLS, FINE-SILTY, MIXED

Havrelon TYPIC USTIFLUVENTS, FINE-LOAMY, MIXED (CALCAREOUS), FRIGID

Fs 1 Fort Collins silt loam, 4 to 8 percent slopes

Fort Collins

BOROLLIC HAPLARGIDS, FINE-LOAMY, MIXED

Hm 111 Heldt silty clay loam, 4 to 8 percent slopes

Heldt BOROLLIC CAMBORTHIDS, FINE, MONTMORILLONITIC

Me 31 McRae silt loam, 4 to 8 percent slopes McRae USTOLLIC CAMBORTHIDS, FINE-LOAMY, MIXED, MESIC

Mg 570 Midway and Elso rocky soils, 35 to 75 percent slopes

Midway TYPIC USTORTHENTS, CLAYEY, MONTMORILLONITIC (CALCAREOUS),


Map Unit Symbol

Acres Soil Map Unit Name Soil Series Taxonomic Classification

Mt 28 Midway-Elso association, 8 to 35 percent slopes

FRIGID, SHALLOW Mw 31 Midway-Thurlow association, 8 to 15

percent slopes Ro 49 Remmit-Ocean lake fine sandy loam, 8 to

25 percent slopes Remmit USTOLLIC CAMBORTHIDS, COARSE-

LOAMY, MIXED, MESIC Ocean Lake

USTIC TORRIPSAMMENTS, MIXED, FRIGID, SHALLOW

Rs 91 Ringling silty loam, 20 to 50 percent slopes

Ringling TYPIC HAPLOBOROLLS, LOAMY-SKELETAL OVER FRAGMENTAL, MIXED

Rt 3,395 Ringling-Cabba association, 15 to 50 percent slopes

To 12 Thurlow silty clay loam, 4 to 8 percent slopes

Thurlow USTOLLIC HAPLARGIDS, FINE, MONTMORILLONITIC, MESIC

Sl 16 Shale outcrop Total 14,053

1

Soil Map Units listed are commonly associations of one or more soil types. For example, the Farland-Cabba association (Fk) consists of about 70% Farland silt loam and 30% Cabba silt loam. These associations are described in the 1971 Powder River Soil Survey. For the purposes of displaying soil types for the BCLMP area, similar soil types were grouped together on the soils maps in Appendix A. For example, all the Farland soil types (Fe, Fh, Fk, Fl, Fm, Fd) are identified as Farland.


In 1980, the BLM and NRCS conducted a three-week field review of soil mapping units for parts of the Powder River area, specifically BLM lands around Broadus. The results of this review redefined some of the map units that were mapped as part of the original Powder River Area Soil Survey. This review found that the Cabba association map unit consists mainly of deep and moderately deep soils with around 20 to 35 percent Cabba soils, and that the published soil survey under represented the amount of deep and moderately deep soils, and over represented the amount of shallow soils in the Cabba Association map unit in the areas reviewed. This finding is important in this analysis, as the effects of management on deeper soils might have less severe or different limitations than on shallow soils. The major soil components in these map units are Cabba, Midway, Farland, and Ringling (Table 3.3.1). These soils are well-drained medium textured soils. Cabba and Midway are generally less than 20 inches to shale beds. Other important soils are Havrelon, Campspass, and Barvon (Table 3.3.1). These are deep, well drained medium textured soils. As described in the published soil survey, rock outcrop and shallow soils make up approximately 7,030 acres, which is slightly less than half of the BCLMP area, though these shallow soils may be over-represented.

C. FIELD SURVEYS Soil scientists and other resource specialists surveyed proposed treatment units in the BCLMP area. The objectives of the field review were to:

1. Assess current soil quality condition of the proposed units; 2. Determine consistency of soil mapping to existing conditions on the land; and 3. Assess the suitability or unsuitability of the area for native surface temporary roads.

All units that were identified as having previous commercial timber were visited and assessed for existing soil quality condition by a soil scientist.

Field review of proposed treatment units consisted of a rapid assessment of representative sites (2005) and intense sampling of 19 sites (2007). Additional soils monitoring has been completed on the Custer NF since 2007 to assess long term soils effects following timber harvest. These reviews are described below.

Rapid Assessment In 2005, soils were surveyed using a rapid assessment method, which consisted of traversing representative units and verifying soil survey information, as well as visually estimating existing disturbance. The Forest soil scientist traversed proposed representative treatment units to identify litter depth, soil shallowness (<20 inches to bedrock), previous disturbance, coarse woody debris, evidence of landslides and general soil condition. Digital photos taken during this field review are available in the project record.


Evidence of very old stumps was visible in some units. These stumps were highly decomposed and widely spaced, and some of them were associated with old trails or wagon roads. They were fairly narrow with incised wheel tracks, and covered with grass and in many cases, covered with post/pole size trees consistent with vegetation found throughout the unit. Over all litter depth ranged from ½ inch to 3 inches thick, and averaged 1.4 inches across 190 sampled sites. Similar to the 1980 field review by the BLM and SCS (see page 3-95), the results of this field survey found that shallow soils are over represented in the 1971 published soil survey, and that the Cabba association map unit in this area are comprised of approximately 50% deep and moderately deep soils and 30% to 40% shallow soils.

Intense sampling

In 2007, soils were intensely sampled on 19 sites following the 2007 Northern Region Soil Quality Monitoring Protocol to determine the percentage of area in each of four disturbance classes and to validate the 2005 traverse review. The four disturbance classes are summarized in Table 3.3.2 below. Note that any single visual attribute was sufficient for establishing the soil disturbance class. Based on the amount of observed disturbance, sites were assigned a disturbance rating, which is listed in Table 3.3.3 for each of the 19 sampled sites. Table 3.3.2: Soil Disturbance Classes Disturbance Class

Soil Surface Soil Compaction Physical Soil Condition

Class 0 No evidence of past equipment operation. No depressions or wheel tracks evident. Forest floor layers present and intact. No soil displacement evident. No management-generated soil erosion. Litter and duff layers not burned. No soil char. Water repellency may be present.

Class 1 Faint wheel tracks or slight depressions evident and are <5 cm deep. Forest floor layers present and intact. Surface soil has not been displaced and shows minimal mixing with subsoil. Burning light: Depth of char < 1 cm. Accessory: Litter charred, or consumed. Duff largely intact. Water repellency is similar to pre-burn conditions.

Compaction in the surface soil is slightly greater than observed under natural conditions. Concen-trated from 0-10 cm in depth.

Change in soil structure from crumb or granular structure to massive or platy structure, restricted to the surface 0-10 cm. Platy structure is non-continuous.

Class 2 Wheel tracks or depressions are 5 to 10 cm deep. Accessory: Forest floor layers partially intact or missing Surface soil partially intact and may be mixed with subsoil. Burning moderate: Depth of char 1- 5 cm. Accessory: Duff deeply charred or consumed. Surface-soil water repellency increased compared to the pre-burn condition.

Increased compaction is present from 10-30 cm in depth.

Change in soil structure from crumb or granular structure to massive or platy structure, restricted to the surface 10-30 cm. Platy structure is generally continuous. Accessory: Large roots may penetrate the platy structure, but fine and medium roots may not.

Class 3 Wheel tracks and depressions highly evident with depth >10 cm. Accessory: Forest floor

Increased compaction is deep in the soil

Change in soil structure from granular structure to


layers are missing. Evidence of surface soil removal, gouging, and piling. The majority of surface soil has been displaced. Surface soil may be mixed with subsoil. Subsoil partially or totally exposed. Burning High: Depth of char > 5 cm. Accessory: Duff and litter layer completely consumed. Surface soil is water repellent. Surface reddish or orange in places.

profile (> 30 cm in depth).

massive or platy structure extends beyond 30 cm in depth. Platy structure is continuous. Accessory: Roots do not penetrate the platy structure.

A disturbance class rating of 2 or 3 was assumed to be detrimental and is based on transect data. Two sites had disturbance class 2 based on identified platy or massive structure. However, these sites also had more litter than average and few notes on the extent of roots and pores. In addition no data was collected on actual bulk density. No disturbance class 3 was identified. See Project Record for transect data field notes. There was also some discussion between soil scientists on what is detrimental. In other monitoring a disturbance class 2 was not considered detrimental. Discussion notes are included in the Project Record. In addition to determining the disturbance class, groundcover was described using toepoint sampling, and coarse wood was measured using a modified Brown’s method along 50 foot transects. Key measurements taken at each of these sites are provided in Table 3.3.3 for each of the 19 sites, and include the following attributes:

• Depth of litter • Depth of the A horizon • Texture • Structure • Percent ground cover (litter, basal

vegetation, bare ground, coarse wood, and rock)

• Coarse woody debris (tons/acre) • Aspect • Slope • Disturbance class

The field review indicated that ground cover included an average of 67.2% litter, 22.2% basal vegetation, 2.2% bare ground, 7.2% coarse wood, and 1.2% rock. Coarse woody debris averaged 6.2 tons/acre. A majority of the sampled soils are coarse textured, having a high cobble and gravel content (Table 3.3.3). This is a sign that they will resist erosion. A majority of these sites also have subangular blocky or granular structures. This is an indicator that these sites do not have residual compaction or detrimental effects from historic management. Sites with massive or platy structures (1 and 7) may have enduring compaction effects and little pore space for root elongation and water infiltration. There is very little bare ground, a sign of resistance to erosion and some sites have high coarse woody debris content, reflecting a buildup of woody material from fire exclusion. Of all the sites sampled in 2007, six percent was found in detrimental condition (disturbance rating 2). However, these sites have “coarse textured soils with a high cobble and gravel content, which resists erosion. A disturbance classification rating of 2, based on platy soil structure containing roots and channels within and between the platy structure may not necessarily be detrimental. In addition, the rating if 2 indicates that these conditions exist between the depths of 15 and 30 cm. They do not exist deeper than 30 cm.


Table 3.3.3: Key Measurements for Intensively Sampled Sites in the BCLMP Area. Inches Percent Ground Cover Site Litter Depth Depth

A Texture Structure Litter Basal Veg Bare Ground Coarse Wood Rock CWD Aspect Slope Disturbance

Class

1 3 1 co sa lo platy/SAB 64 12 6 16 2 29 NE 18 2

2 1 3 co sa lo SAB/gran 70 12 2 12 4 2.5 East 15 1

3 0 1.5 gr sa cl SAB 76 14 6 2 2 0 East 33 1

4 1.5 1 gr sa lo granular 66 16 0 18 0 11.8 NW 8 1

5 2 1 gr sa lo SAB/gran 80 14 2 4 0 0 NE 50 1

6 1 0.5 gr sa lo granular 78 10 0 12 0 3.6 North 35 1

7 2 0 gr sa lo massive 70 20 0 4 6 2.2 NE 19 2

8 2 9 loam SAB/gran 44 48 0 8 0 1.7 North 24 1

9 1.5 1 cl loam granular 60 28 0 10 2 5 North 28 1

10 2.5 1 cl loam SAB 66 24 2 8 0 0 North 17 1

11 2 1 cl loam SAB 70 26 0 4 0 0 North 12 1

12 3 0.5 co sa lo granular 76 14 0 6 4 21.1 North 26 1

13 1.5 7 loam SAB 68 24 0 8 0 11.2 North 17 1

14 1.5 0.5 co loam SAB 74 20 0 6 0 7 North 35 1

15 3.5 1 gr sa loam SAB 56 34 0 10 0 9.8 North 18 1

16 0 4 gr cl loam SAB 64 28 6 2 0 2.5 NE 4 1

17 1.5 4 sa loam granular 62 34 0 4 0 5 East 7 1

18 0.5 4 vc sa loam SAB 66 26 4 2 2 3.6 East 6 1

19 1.5 1.5 gr loam SAB 66 18 14 2 0 2.2 East 21 1

Note: This table is a summary of intensively sampled sites. Transect data can be found in Robinson, 2010 field notes filed in the Project Record. co=cobbly, sa=sand, lo=loam, gr=gravelly, cl=clay, vc=very cobbly, SAB=subangular blocky, gran=granular, veg=vegetation, CWD=coarse woody debris.


Forest Wide Soils Monitoring A soil monitoring project was completed during the summers of 2009-2010 on the Custer National Forest, Sioux and Ashland Ranger Districts to review the current physical condition of soils that have under gone management disturbance (e.g. timber harvesting, cattle grazing, etc.) within the last 15 years. A total of 187 bulk density soil samples were collected from 22 cutting units, including sites within the BCLMP area (EO6, EO25, and EO33). These cutting units ranged from no recent management activity (controls) to units that were disturbed 1-5, 6-10, and 11-15 years ago. The primary management disturbance occurring in these units was timber harvest. Different types of silvicultural prescriptions (i.e. seed tree, shelterwood, and commercial thin) were also reviewed at as a measure of harvest intensity. Data for a majority of cutting units sampled did not show many of the visual indicators associated with the higher disturbance classes (e.g. deep rutting, surface soil displacement, compaction, etc.). The preliminary results of this monitoring project indicate that detrimental soil conditions approach zero approximately five to ten years after commercial timber harvest activities. A complete copy of this interim monitoring report (Robinson and Lane, 2009-2010) is provided as Appendix F of this FEIS.

Conclusions Based upon the results of the 2005 and 2007 field review, and continued forest wide monitoring of detrimental soil impacts, the soil scientist determined:

1. The areas proposed for mechanical treatment (regeneration harvest and commercial thinning) currently meet soil quality standards. It is estimated that current soil disturbance in all proposed mechanical treatment units is in the 1% to 2% range, and in only a few cases where existing unclassified roads occur does soil disturbance approach more than 2% of a unit;

2. It appears the published Powder River Area Soil Survey (USDA SCS 1971) under-

estimates the amount of deep and moderately deep soil mapped in the Cabba association map unit; and

3. There appear to be few areas that are not suitable to be used as temporary roads or

trails.


III. EFFECTS OF ACTION ALTERNATIVES (A, B, &C) A. ASSUMPTIONS, METHODOLOGY & SCIENTIFIC ACCURACY, AND

INFORMATION USED FOR SOILS ANALYSIS The soils effects analysis assumes that all of the practices outlined in Design Features and Mitigation Measures Specific to the Action Alternatives (Chapter 2, Table 2.14) would be implemented and be effective. The effects analysis will:

1) Show the expected amount of soil disturbance resulting from implementation of the alternatives, and

2) Describe the risk that the expected amount of disturbance would be exceeded. The soils analysis is based on the current soil condition and analyzes the effects to soil quality caused by implementation of the proposed management activities. Soil effects are a result of detrimental soil disturbances. The Forest Service Manual FSM R-1, Supplement No. 2500-99-1 defines Detrimental Disturbance as the condition where established soil quality standards are not met and the result is a change in soil quality. This Manual also states that at least 85 percent of an activity area be maintained in satisfactory soil conditions. The Forest Service Manual defines the Regional soil quality guidelines in terms of detrimental soil disturbance, which includes:

• Compaction • Rutting • Displacement • Severely-burned Soil • Surface Erosion • Soil Mass Wasting (Mass Failure)

While detrimental soil disturbances are the basis for the effects analysis, not all soil disturbances have a detrimental effect on soil productivity. For example, loss of less than one inch of topsoil over less than 100 square feet is not a detrimental soil disturbance nor is light compaction that causes less than a 15 percent increase in bulk density or that does not elevate bulk density to levels that impede root growth (USDA 1999). B. DESCRIPTION OF SPATIAL AND TEMPORAL BOUNDS USED FOR

EFFECTS ANALYSIS Direct, indirect and cumulative effects are discussed in terms of the activity areas. The Region 1 Supplement 2500-99-1 (see project record) defines an activity area as a land area affected by a management activity to which soil quality standards are applied. Examples include timber harvest units, landings and temporary roads; mechanized fuel treatment units; and prescribed burn units. Activities outside of the locations of proposed management are not subject to a cumulative effects analysis because they do not overlap spatially with the lands being proposed


for management in the BCLMP. Soil effects do not extend off of the piece of ground where they occur. This analysis addresses the potential effects of this project on soil productivity over the next rotation of trees, which is approximately 120 to 200 years. Compaction lasts 10 to 70 years (Gonsior 1983, p. 13 - 16). Monitoring of 10-20 year old timber sales on the Custer National Forest showed very few areas having compaction that is considered detrimental soil disturbance, indicating recovery of the compacted soils has occurred (see project record for Interim Soil Quality Monitoring Report, Robinson and Lane, 2009-2010) Reductions in organic matter content recover quickly as vegetation grows. Organic debris accumulates on the surface and roots grow and are decomposed in the soil. These organic materials break down and release nutrients and improve the quality of the soil by improving its structure and reducing compaction and other detrimental soil disturbances. Loss of organic matter is a short-term change lasting about 10 years once vegetation returns to the soil. Soil erosion would be controlled through the use of erosion control measures, using BMPs such as applying slash, limiting mechanical treatment on steep slopes and others. In addition, bare soils would either be vegetated with native seed or would naturally recover as vegetation returns to the disturbed sites. Any erosion that occurs would be short lived, most likely occurring during the time between the soil disturbance and the implementation of erosion control measures. C. DIRECT AND INDIRECT EFFECTS TO SOIL QUALITY FROM ACTION

ALTERNATIVES Summary of Action Alternatives The Action Alternatives include a combination of mechanical and non-mechanical treatments, and prescribed fire to reduce surface, ladder and canopy fuel loads. Mechanical mastication is also a potential tool of post commercial activity fuels treatment. FSM 2500 requires at least 85 percent of an activity area be maintained in satisfactory soil conditions. No more than fifteen percent detrimental soil disturbance is allowed per activity area (i.e. treatment unit). Detrimental soil disturbance may be minimized by:

• Limiting the area used for skid trails and landings, and • Implementing timing and equipment requirements (project design criteria) that have the

potential to reduce the amount and degree impacts on the skid trails.

Minimizing the area occupied by landings and skid trails to reduce the detrimental effects on soil productivity from changes in physical soil properties are recommended in several papers (Adams, 1998; Garland, 1997; Williamson and Nielson, 2000). For example, Garland (1997) noted that designated skid trails spaced 100 feet apart, impacts 11 percent of the harvest area.


A design feature (Chapter 2, Table 2.14) requires field operation when soils are free of excess moisture (not wet), or frozen. The ground would be deemed too wet to operate if the equipment would form ruts or smear the soil. Forest Service personnel would determine when conditions are adequate for operations. Operating equipment on skid trails when the soils are drier than field moisture capacity may further minimize soil disturbance. Startsev and McNabb (2001), and McNabb et al., (2001) found that soil compaction is reduced when soils are drier than field capacity. Williamson and Nielson (2000) noted that rutting and puddling are most often associated with logging on soils that are wet. Generally, soils on the Ashland RD are dry during the summer and this condition often lasts through September. Most summer logging would occur when soils are dry. Operating on low soil moisture conditions has the potential to reduce the detrimental disturbance on skid trails. Thus the area with detrimental disturbance has potential to be less than the area of skid trails and landings. Proposed mechanized treatment (cable or tractor) for proposed treatment unit by alternative is summarized in Appendix D. The majority of units would be harvested by tractor logging with whole tree yarding. Under Alternative A, 123 acres on nine units would be harvested by cable logging. Alternatives B and C do not propose any cable logging, as the nine units would not be treated in these alternatives. Appendix D identifies proposed activities by unit number. The information in this table includes the prescription, harvest system (cable or tractor), acres by alternative, whether there was previous commercial harvest in the unit, soil quality review, and the estimate percent of detrimental soil disturbance that currently exists, and 10 years post treatment.

Soil Productivity Disturbance impacts on soil productivity are dependent on the type of soil in the harvest operations area and the location of organic matter in the soil profile (Page-Dumroese, et al. 2000).


All direct effects on soil physical characteristics would occur within the boundaries of the proposed activity areas. More specifically, most detrimental effects would be concentrated on the skid trails, temporary roads and landings. Reduced productivity is caused by detrimental soil disturbances such as soil compaction, displacement, rutting, or soil erosion. Under all of the action alternatives, the proposed treatment areas would be harvested using designated trails and landings that are laid out to occupy less than 15 percent of the activity unit. To the extent feasible, trails and landings will utilize existing roads and trails in treatment units that were previously harvested (Units 17, 29, 61, 7B, 16, 44A, 44B, 49A, 49B, and 49C). Reuse of existing roads and trails will reduce the amount of new disturbance, as will operating under low moisture, or over snow or frozen ground. Roads and trails may not be used during wet periods.


As displayed in Table 3.3.3, many of the soil textures that were sampled are considered coarse textured soils. Coarse textured soils may be able to better withstand compaction effects compared to fine textured soils. In some cases, an increase in compaction of coarse textured soils might be beneficial to plant growth by allowing water to be held in the soil and making it more available to plants, rather than draining through the soil profile. During the past two decades, the level of concern for maintaining soil productivity has increased and along with this has come implementation of management practices that better protect the soil. These changes include use of designated skid trails, operating when soils are dry or when winter conditions would protect soil productivity, ripping skid trails and other restoration activities. Restoration.

Under all action alternatives, skid trails and landings would be lightly ripped upon completion of the prescribed treatment. The goal would be to reduce soil compaction and meet the direction provided in Region 1 Supplement 2500-99-1 (USDA 1999). Several studies discuss the effectiveness of ripping as a soil restoration activity. Studies cited by Froehlich and McNabb (1983) showed up to 39 percent improved seedling survival and growth after tilling compacted soils. The same study showed height growth gains of 8 to 73 percent. A publication by Dick, et al. (1988) found rehabilitation treatments of subsoiling (tilling) restored biological processes that were reduced by soil compaction. In general, tilling or scarifying a compacted soil improves productivity by reducing the resistance of soil to root penetration, and providing improved soil drainage and aeration to enhance seedling establishment and tree growth (Bulmer 1998, p 10 and 13) and improve the environment for soil organisms. The goal of soil restoration is to set the stage for the soil to begin the recovery process. Soil restoration is not an immediate result of ripping, planting, or any other activity.

Cable Logging.

Under Alternative A, approximately 123 acres would be cable logged in nine treatment units. No cable logging is proposed in Alternatives B and C as these treatment units were eliminated. Cable logging has less detrimental soil disturbance compared to ground based tractor logging. There are no skid trails. In addition, Forest Service contracts require one end of the log to be suspended for cable harvest systems, which further minimizes detrimental soil disturbance.

Slash Piling.

Under all action alternatives, mechanical slash piling or fuel reduction that is not hand thinning would be accomplished with excavators, or similar machines that are light on the ground. This method reduces the aerial extent of detrimental soil impacts from the site preparation activities. Chippers mounted on tracked equipment similar to small excavators or a skidsteer (or bobcat) would create soil effects similar to this equipment. No additional excavated disturbance will occur and the equipment will operate on existing litter/slash layer.


As described in Chapter 2 and Appendix B, fuel loads in treatment units within the interior of the BCLMP area would be reduced to a range of three to seven tons per acre. Fine fuel loads (0-3”


diameter) would not exceed three tons per acre. Coarse Woody Debris (CWD) in the 3-12”+ diameter range would be retained when available, and at a minimum of four tons per acre. Fuel loads in treatment units adjacent to private land would be reduced to a range of three to five tons per acre. Fine fuel loads would not exceed two tons per acre. CWD would be retained when available, and at a minimum of three tons per acre. All of the proposed treatments are designed to increase the resiliency of this area to future wildfire. As a result the amount of organic matter and its associated nutrients would be reduced. In all cases, the amount of material left on site would be more than that left by a severe wildfire. In a study in northwestern Montana that looked at logging followed by slash burning, Jurgenson et al (1981) concluded there would be no long-term depletion of nitrogen reserves and that losses of nutrients associated with organic matter are temporary changes. The total amount of nutrients on a site would likely be reduced where large amounts of organic matter would be removed. However, the plant available nutrients (those released from organic matter) would increase because sun and moisture would be increased in the treated stands, conditions that speed the breakdown of the remaining organic matter and the release of nutrients (Harvey et al., 1994). After project implementation competition between trees would be reduced because fewer trees would remain on the sites. This situation could result in more available nutrients and water for the remaining trees (Powers et al., 2005). Whole Tree Yarding

. As described in Appendix B, all but 123 acres of the commercial treatments in Alternative A, and all of the commercial treatment in Alternatives B and C would be tractor logged and whole tree yarded to achieve desired fuel levels.

Ground based timber harvests that utilize whole tree yarding have the highest risk of reducing organic matter and affecting nutrient content of the site. In whole tree yarding, the entire tree including the branches and needles, minus those that break off when the tree falls to the ground, are taken to the landing. However, Forest Service contracts require one end of the log to be suspended for tractor harvest systems, which reduces detrimental soil disturbance. At the landing, the branches and needles are trimmed off the tree and put into a pile. This process can remove a large amount of organic material and associated nutrients from the activity area. However, the effect on the ground and on productivity depends on the inherent productivity of the soil, how much organic matter is left behind and whether it is enough to provide what the next forest requires to grow and be healthy. Harvey et al. (1994) state that it is difficult to resolve the loss of nutrients on sites with high fire potential. One potential result of this proposed project would be to reduce the risk of wildland fire by reducing the amount of fuels within the activity areas and by reducing the spacing of the remaining trees. More nutrients and organic matter would remain on all these sites after treatment than compared to a similar site burned by a severe wildfire. All harvest prescriptions would leave a portion of the existing stand on the site. How much of the existing stand remains is dependent on the silvicultural prescription for each stand. The


proposed treatments are described in detail in Appendix B. Timber management that leaves trees on the ground also leaves nutrients on the site for sustaining the future forest. Excavator Piling.

Excavator piling will be used in association with mechanical treatment to reduce fuel loadings and achieve desired fuels objectives (see Appendix B). The amount of organic matter on the site would be reduced but not eliminated after project implementation.

Chipping or Mastication.

Alternative A would treat approximately 2,073 acres by hand thinning or mechanical mastication. Alternative B would treat approximately 2,179 acres by hand thinning or mechanical mastication. Alternative C would treat approximately 1,849 acres by hand thinning or mechanical mastication.

Chipping is an option for reducing the amount of fuels on some activity areas after treatments are complete or in some non-commercial treatment areas. Chipping or mechanical mastication, which shreds brush and trees into woodchips, is increasingly prescribed for wildfire mitigation as an alternative to tree thinning and burning the resulting slash. Chipping is carried out by equipment similar to a small excavator, skidsteer, or bobcat, and reduces the size of fuels from large or coarse wood to fine and medium size wood/fuel. There would be no creation of roads or trails and the equipment would operate on the existing slash/litter layer. In addition, chipping leaves all the treated organic material on the soil surface where it contributes to the nutrient supply for the future forest. Much of the existing literature indicates that there is little effect on soil compaction, erosion, or soil nutrients (Hatchett, et. al., 2006; Hunter et. al. 2007; Moghaddas and Stephens, 2008; Moghaddas and Stephens, 2007) though studies are limited. Owen, et. al. (2009) suggests that mechanical mastication has less detrimental soil impact than slash pile burning and may reduce the occurrence of exotic plants. Monitoring of recent mastication treatments on the Sioux Ranger District indicates that these areas meet regional soil quality guidelines (see Ekalaka Hills Mastication Project, Soil Quality Monitoring Report, September 2009 in the Project Record). Tracked equipment, if used, would further minimize disturbance. Any new ground disturbance will be due to operation of the equipment used for mechanical mastication and will not exceed Regional Soil quality guidelines (USDA FS September 14, 2010, Appendix B Soil Disturbance Classes, National Soil Disturbance Monitoring Protocol). Hand Treatments.

Under Alternative A, 2,118 acres would be hand thinned, and an additional 2,102 acres would be either hand thinned or mechanically thinned via mastication. Under Alternative B, 2,206 acres would be hand thinned, and an additional 2,179 acres would be either hand thinned or mechanically thinned via mastication. Under Alternative C, approximately 1,767 acres would be hand thinned, and 1,849 acres would be either hand thinned or mechanically thinned via mastication. In these units, some of the hand-thinned material would be put into small hand piles and burned.

Because the hand piles are small (approx. 8’ x 8’ x 6’) , the amount of area disturbed by burning them are usually less than 10 feet in diameter and they would burn with low amounts of heat.


The amount of nutrients lost during burning would be minor. The ash where the hand piles are burned would contain nutrients available to nearby vegetation.

The amount of heat generated by small hand piles is less than that created when large machine generated piles burn (approx. 12’ x 30’ x 60’). As a result, the amount of nutrients that go up with the smoke would be minor. As discussed by DeBano, et al. (1999, p.112) the effect would not likely be adverse to soil productivity because nutrient replenishment mechanisms remain on the site. These mechanisms include the presence of nitrogen fixing organisms, both plant and microorganisms, organic matter that is left on the soil surface, and living vegetation on the site. As these areas are generally small, recruitment from adjacent areas would occur.

Vegetation and soil microorganisms remaining in the harvested sites would use and store nutrients released from organic matter, preventing nutrients from leaching from the site. The amount of nutrients leached as a result of the proposed project would be less than the loss after wildland fires because of the presence of living trees, shrubs, grasses, and forbs left in the treatment units. Prescribed Fire.

The action alternatives include the use of prescribed fire to reduce fuel loads. Alternative A would burn 8,057 acres, Alternative B would treat 8,054 acres, and Alternative C would treat 7,562 acres.

The proposed burning would occur under conditions that promote light or moderate burn temperatures, which would keep the soil effects within or less than the natural range of variability resulting from wildfire. These less severe burn conditions would preserve the productive potential of the soils. The amount of nutrients available to plants would increase as a result of the burning. The proposed burn conditions would allow many plants to quickly return to the burned sites from unburned roots and seeds in the soil (Certini, 2005, Neary et al., 2007). Vegetation that returns after the fire would take up the available nutrients, keeping them on the site and reducing the risk of nutrients leaching beyond the reach of plants. Native forest vegetation would remain on the site, including some of the existing trees and new trees.

Soil Organisms

Because the amount of detrimental physical soil changes would be minimized, and because organic matter in various forms would remain on the proposed units, the effects to soil microorganisms would be minor. Soil microorganisms are mobile. They can move from undisturbed sites to disturbed sites. Thus their loss is not permanent. A variety of organic matter will remain on all sites, including living trees and other forest vegetation. In addition, the organic layer on the soil surface will be retained over at least 85 percent of the area, providing habitat and nutrients for soil microorganisms.

Soil Erosion The action alternatives involve varying amounts of hand thinning, mastication thinning and timber harvest. See Tables 2.1, 2.2 and 2.3 in Chapter 2, and Appendix B.


Soil erosion would be unlikely to occur as a result of the chipping or hand treatments. Lopping and scattering slash would add cover to the soil surface, reducing the risk of erosion. Burning hand piles would create small areas of disturbance that would be unlikely to erode because slopes are gentle and the disturbance is of small extent. Mastication / chipping is carried out by equipment similar to a small excavator, skidsteer, or bobcat. There would be no creation of roads or trails and the equipment would operate on the existing slash/litter layer. In addition, chipping leaves all the treated organic material on the soil surface where it contributes to the nutrient supply for the future forest. Management activities that leave organic matter on the soil surface also reduce soil erosion. Using these management tools in the proposed project would minimize soil erosion. Mechanical equipment operation would be most likely to cause soil erosion. Implementing the following best management practices would minimize the risk of soil erosion:

• Reduce the area where equipment operates, • Locate landings on relatively flat ground that can be drained, • Locate skid trails on slopes less than 35 percent that have soils with a low or

moderate erosion hazard and • Use erosion control features such as water bars, planting vegetation, and placing slash

on disturbed soils.

Mass Wasting / Soil Stability The proposed mechanized treatments are planned for a landscape with slopes generally less than 30 percent, which greatly reduces the risk of mass failures. One area of concern that was identified is the existence of old slumps. These features in the project area were found below Road 44094 in NW1/4 Section 23. They consist of a series of flat benches and rolling rounded hills. These features now appear to be stable and have commercial size trees growing in them. A treatment unit was dropped from this area prior to release of the DEIS due to steep slopes and bad access. Treatment units proposed under the existing Action Alternatives within the NW quarter of section 23 do not have any of these characteristics. In the event that these features are found within a proposed treatment unit, the sale administrator shall consult with the Forest Soil Scientist or Hydrologist before establishing any temporary roads or skid trails in the area. If possible, these areas could be excluded from proposed mechanical treatment by adjusting cutting unit boundaries. This one area of concern suggests that in general, the area has a low mass failure risk. Implementation of road BMP’s associated with this project would reduce concentrations of road surface drainage, thereby reducing the risk of mass failures associated with road drainage.

Temporary Road Construction and Road Obliteration Alternative A (the Proposed Action) would require construction of 18.2 miles of temporary roads, Alternative B would require 15.2 miles, and Alternative C would require 5.7 miles.


Many of the proposed temporary roads access multiple cutting units. Tables 3.3.4, 3.3.5, and 3.3.6 show the length of the proposed temporary roads, the units accessed by each road, and to which the disturbance was assessed.


Table 3.3.4: Alternative A: Temporary Roads Temporary

Road Units Accessed Length

(Miles) Area disturbed

(sq. ft.) Total Area

Disturbed (acres)

1 60 0.38 23,787.4 0.55

2 58, 59 0.1 6,274.3 0.14

3 56 0.12 7,598.11 0.17

4 54, 55 0.74 47,188.1 1.08

5 51, 52, 53 0.82 52,157.4 1.2

6 48, 52 0.73 46,433.9 1.07

7 51 0.19 12,191.3 0.28

8 47A, 47B, 48 0.27 17,180.5 0.39

9 47B, 48 0.05 3,400.48 0.08

10 49A, 48 0.13 7,984.94 0.18

11 44D, 45A, 45B 0.11 6,853.26 0.16

12 42, 43, 44C, 44D 0.4 25,513.1 0.59

13 33A 0.03 1,997.49 0.05

14 30 0.19 12,205.1 0.28

15 31A 0.13 8,491.97 0.19

16 31B 0.27 17,393.6 0.4

17 20, 23A, 23B, 23C 0.91 57,661.3 1.32

18 23B, 23C 0.18 11,708.5 0.27

19 23A, 23C, 23D 0.27 16,848.6 0.39

20 28 0.34 21,426.6 0.49

21 15, 16, 17 0.12 7,861.69 0.18

22 27 0.03 1,693.41 0.04

23 15, 16, 17, 27 0.43 27,363.5 0.63

24 19 0.07 4,498.36 0.1

25 13 0.26 16,181.7 0.37

27 12 0.33 20,727.5 0.48

28 9, 10A, 10E 0.35 22,119.5 0.51

29 9 0.06 3,691.37 0.08

30 8 0.32 20,150.9 0.46

31 8 0.36 22,745.7 0.52

32 5 0.17 11,046.7 0.25

33 1C, 2, 3, 4 0.65 41,163.2 0.94

34 1A, 1B 0.89 56,392.8 1.29

35 3, 4 0.28 17,763.5 0.41

36 1C, 2 0.31 19,656.3 0.45

37 1A, 0.14 8,711.28 0.2


Temporary Road

Units Accessed Length (Miles)

Area disturbed (sq. ft.)

Total Area Disturbed (acres)

38 1A 0.13 8,497.05 0.2

39 1A 0.11 6,743.12 0.15

40 5, 7B 0.34 21,772.4 0.5

41 5 0.02 1,444.12 0.03

42 EO 11 0.74 46,639.8 1.07

43 EO 12 0.08 4,873.05 0.11

44 EO 11 0.15 9,681.32 0.22

45 EO 11 0.11 7,030.25 0.16

46 EO 11 0.14 8,681.03 0.2

47 EO 8, EO 9, EO 10 0.63 40,225.9 0.92

48 EO 5, EO 6 0.48 30,493.3 0.7

49 EO 15, EO 16, EO 17 0.43 27,180.1 0.62

50 EO 22, EO 23 0.75 47,364.6 1.09

51 EO 22 0.25 16,053.6 0.37

52 EO 23 0.09 5,598.77 0.13

53 EO 21 0.13 8,370.18 0.19

54 EO 21 0.1 6,298.91 0.14

55 EO 24 0.03 1,716.43 0.04

56 EO 24, EO 25 0.26 16,592.9 0.38

57 EO 25, EO 26 0.07 4,272.29 0.1

58 EO 25, EO 29, EO 30, EO 31, EO 32 1.12 70,674.5 1.62

59 EO 27, EO 28 0.38 24,319.2 0.56

60 EO 28 0.17 10,732.6 0.25

61 EO 28 0.11 7,194.64 0.17

62 EO 28 0.1 6,063.21 0.14

63 EO 28 0.17 11,014.9 0.25

Alt. A Total 18.24 1,155,592 26.53

Table 3.3.5: Alternative B: Temporary Roads

Temporary Road




1 60 0.38 24,076.8 0.55

2 58 0.1 6,336.0 0.15

3 56 0.12 7,603.2 0.17

4 54 0.74 46,886.4 1.08

5 51, 52, 53 0.82 51,955.2 1.19


Temporary Road




6 48, 52 0.73 46,252.8 1.06

8 47B, 48 0.27 17,107.2 0.39

9 47B, 48 0.05 3,168.0 0.07

12 42, 43 0.21 13,305.6 0.31

14 30 0.21 13,305.6 0.31

15 31A 0.18 11,404.8 0.26

16 31B 0.27 17,107.2 0.39

17 23A, 23B, 23C, 23D 0.69 43,718.4 1.00

18 23B, 23C 0.18 11,404.8 0.26

20 28 0.33 20,908.8 0.48

23 15, 16, 17 0.33 20,908.8 0.48

25 13 0.07 4,435.2 0.10

27 12 0.33 20,908.8 0.48

28 9, 10E 0.16 10,137.6 0.23

31 8 0.36 22,809.6 0.52

32 5 0.3 19,008.0 0.44

33 1C, 2, 3, 4 0.65 41,184.0 0.95

34 1A, 1B 0.89 56,390.4 1.29

35 3, 4 0.28 17,740.8 0.41

36 1C, 2 0.31 19,641.6 0.45

37 1A 0.21 13,305.6 0.31

40 5, 7B 0.34 21,542.4 0.49

44 EO11 0.44 27,878.4 0.64

45 EO 11 0.11 6,969.6 0.16

47 EO 8, EO 9, EO 10 0.63 39,916.8 0.92

48 EO 5, EO 6 0.48 30,412.8 0.70

49 EO 15, EO 16, EO 17 0.43 27,244.8 0.63

50 EO 23 0.89 56,390.4 1.29

51 EO 23 0.19 12,038.4 0.28

52 EO 23 0.11 6,969.6 0.16

53 EO 21 0.21 13,305.6 0.31

56 EO 24, EO 25, EO 26 0.39 24,710.4 0.57

58 EO 25 0.1 6,336.0 0.15

59 EO 27, EO 28 0.33 20,908.8 0.48

61 EO 27, EO 28 0.19 12,038.4 0.28

62 EO 28, EO 29, EO 30, EO 31, EO 32, EO 34 0.92 58,291.2 1.34

63 EO 28 0.26 16,473.6 0.38

Alt. B Total 15.19 962,438.4 22.09


Table 3.3.6: Alternative C - Temporary Roads Temporary

Road Units Accessed Length

(Miles) Area Disturbed

(sq. ft.) Total Area

Disturbed (acres) 1 60 0.38 24,076.8 0.55

2 58 0.1 6,336.0 0.15

3 56 0.12 7,603.2 0.17

4 54 0.74 46,886.4 1.08

5 51, 52, 53 0.82 51,955.2 1.19

6 48, 52 0.73 46,252.8 1.06

8 47B, 48 0.27 17,107.2 0.39

9 47B, 48 0.05 3,168.0 0.07

12 42, 43 0.21 13,305.6 0.31

23 15, 16, 17 0.33 20,908.8 0.48

25 13 0.07 4435.2 0.10

27 12 0.33 20,908.8 0.48

28 9, 10E 0.16 10,137.6 0.23

48 EO 5, EO 6 0.48 30,412.8 0.70

62 EO 28, EO 29, EO 30, EO 31, EO 32, EO 34 0.92 58,291.2 1.34

Alt. C Total 5.71 361,785.6 8.31

As described in Chapter 2, temporary roads will be closed and obliterated after management activities are completed. Closure of temporary roads and obliteration would occur using a variety of methods such as scarifying/ripping in a random pattern across the contour of the roadbed, restoring to contour if a cut-slope exists, scattering of debris (where available), seeding (with native vegetation), signing, obstructing with boulders, stumps, or logs, and re-seeding disturbed areas with a noxious-weed free native seed mix appropriate for site conditions. Entrances to some of these roads would be obliterated for a minimum distance of 100 feet or as needed to a length the road would not be seen from the open system road It is difficult to assess the amount of detrimental disturbance associated with temporary roads in the project area. There is a range of type of temporary roads in the project area. Some have cut and fill slopes, while some are on mostly flat ground and only have the vegetation and top soil scrapped off. All temporary roads will be obliterated and restored at the end of the project, per BMPS and project mitigation specifications. Restoration of roads and trails has a high degree of success (Froehlich and McNabb, 1983; Dick, et al. 1988). It is estimated that around one-third to one-quarter the original disturbance would be detrimental. The disturbance to units accessed by multiple temporary roads would still be within the Regional Soil Quality Guidelines (USDA 1999), as shown by results of all previous monitoring which included the effects of temporary road. Commercial timber harvest plans currently include Road 41338A to be used for access to units and as a haul road. The existing District Travel Management Plan (USDA 2009a and 2009b) does not designate this road as open for public use, nor does it identify a need for administrative


use. This road would be decommissioned at the conclusion of the project to maintain consistency with the Travel Management Plan. In addition to Road 41338A, there are other classified and non-classified roads the District Travel Management Plan does not designate as open for public use, nor does it identify a need for administrative use. These roads are also proposed for decommissioning or obliterated as part of the BCLMP Proposed Action. The net result being no permanent new roads would be constructed and approximately 2.1 miles of road identified for decommission or obliteration. (See Appendix A, Map 4, Map 9, Map 13 for road locations.)

Summary of Direct and Indirect Effects to Soil Quality The proposed treatment units all currently meet soil quality standards and will meet soil quality standards at completion of the project (Appendix D). The effects analysis shows that regional soil quality standards can be met by implementing BMPS and design criteria (#7, pages 2-21 to 2-22), using designated skid trails that occupy less than 15 percent of the harvest area, and operating ground-based equipment when soils are dry, by operating in winter on snow or frozen soils, or by operating equipment on a dense slash mat. A design feature prohibits equipment operation on designated roads and trails under wet conditions. The proposed units would retain various amounts of live trees per acre, which would retain and contribute a large amount of nutrients on site. Please refer to Appendix B, which describes desired stand conditions, and Appendix E, which summarizes the amount of large mature trees (> 9” dbh) that will be retained on the landscape. In addition, most of the living forbs, grasses and shrubs would remain along with much of the material on the ground. All of the units would have an active microorganism-rich organic layer on the soil surface. All units would also have 3 to 7 tons of a mixture of coarse to fine woody material left on the units. D. CUMULATIVE EFFECTS OF ACTION ALTERNATIVES Cumulative effects occur when past, present, or foreseeable activities overlap in both time and space with the proposed activities. Thus, cumulative effects to the soils resource are limited to the activity area where the proposed activities would occur. In other words, cumulative effects would occur only where proposed activities occur where previous management has affected soil conditions or where future management may affect soil conditions. Activities outside of the locations of proposed management are not subject to cumulative effects for soils because they do not overlap spatially with the lands being proposed for management in the BCLMP. Soil effects do not extend off of the piece of ground where they occur. The risks of cumulative effects were assessed within each proposed activity area. Cumulative effects consist of the impacts from all past, present, future and proposed activities that overlap in time and space with the proposed project.


Past Activities As Appendix D indicates, ten units proposed for treatment under Alternative A have experienced previous timber harvest. Proposed units 17, 29, and 61 are seed tree removal prescriptions, which call for removing overstory seed trees resulting from a previous harvest or disturbance. Other units identified as having previous commercial timber sale activities include: 7B, 16, 44A, 44B, 49A, 49B, and 49C. Firewood cutting along roads has had minimal effects on soil productivity because it is carried out by hand and the fine branches and needles are left in the woods. Grazing, firewood gathering, camping, and other recreational activities have contributed past disturbance, through the removal of organic matter, compaction, rutting, and displacement. The amount of detrimental disturbance from these activities is incorporated into the existing condition by activity area (see Appendix D). The sum of all past and existing disturbances meets or exceeds regional soil quality guidelines.

Reasonably Foreseeable Future Activities Upon review of the cumulative effects activities table in Chapter 2, Table 2.18, the only reasonably foreseeable future activities that will have an effect on soil productivity in the activity areas are grazing, recreation, and firewood gathering. All other reasonably foreseeable activities do not overlap the activity areas in space or time. The continuation of livestock grazing activities will overlap with the proposed treatments for all alternatives in both time and space. They could potentially contribute to cumulative effects, through the continuation of impacts such as compaction, displacement, and rutting, however, the existing condition indicates it is not detrimental (Appendix D). In addition, if grazing management changes in the future by reducing the timing, duration, and intensity of grazing impacts may decline. Firewood gathering and recreation activities will also continue and could potentially contribute additional effects such as removal of organic matter, compaction, and displacement. These effects are not expected to persist and be as extensive as would be found in the proposed treatments as the equipment used is different and no off road vehicle use is usually permitted.

Combined Effects from Past, Proposed, Ongoing and Foreseeable Activities Cumulative effects on soils are the combination of the existing detrimental disturbance from past activities combined with the estimated disturbance that would result from the proposed project, as well as any impacts from reasonably foreseeable future projects. The units with the highest risk of exceeding the regional soil standards are those that had past activities and still have some detrimental soils disturbance (Units 17, 29, 61, 7B, 16, 44A, 44B, 49A, 49B, and 49C). This risk is low since monitoring past timber sales indicates detrimental soil disturbance is less than three to six percent and estimated disturbance of this proposed project will be less than 15%. Refer to Appendix D.


E. REQUIRED DISCLOSURES FOR ACTION ALTERNATIVES Short-term Uses vs. Long-term Productivity There may be short term impacts associated with Action Alternatives as pointed out in the discussion on direct and indirect effects, but these impacts are not expected to lead to decreases in long-term productivity.

Irreversible/Irretrievable Commitments Irreversible commitments are permanent. No irreversible commitments are identified. Irretrievable commitments are temporary. Please see the section above on direct and indirect effects of the Proposed Action alternative for temporary effects. Unavoidable Adverse Effects No unavoidable adverse effects are expected.

Forest Plan Consistency of Action Alternatives A Forest wide management standard for soil and water quality management states:

Soil and water resources will be managed to maintain or improve quality of watershed, including soil productivity and water quality. Best Management Practices will be applied to project activities to assist in meeting or exceeding state water quality standards.

The existing condition for detrimental soil disturbance ranges from three to six percent for all commercial units. Water and soil quality design features (#7, pages 2-21 to 2-22) require best management practices (Appendix C) to be implemented that will minimize detrimental soil disturbance from proposed treatment. Post harvesting monitoring of past timber harvest on the Custer National Forest indicates that detrimental soil conditions approaches zero approximately five to ten years after commercial timber harvest activities (Project Record, Soil Quality Monitoring Data; Robinson and Lane, 2009-2010). The effects analysis shows that with the implementation of design features and soil and water BMPs, detrimental disturbance ten years after project implementation will be the same as the existing condition (i.e. no effect). Detrimental disturbance is less than 15% pre and post treatment, and complies with Region 1 Soil Quality Standards. The project also includes approximately 2.1 miles of road obliteration, which will improve overall watershed health. These management activities maintain soil productivity and comply with the forest wide management standard cited above. F. CONCLUSIONS FOR ENVIRONMENTAL CONSEQUENCES OF

ACTION ALTERNATIVES The existing condition indicates there is less than three to six percent detrimental soil disturbance within activity areas. The effects analysis shows that regional soil quality standards can be met post treatment by:


• Using designated skid trails, • Operating ground-based equipment when soils are dry, operating in winter on snow or

frozen soils, or by operating equipment on a dense slash mat. • Implementing soil and water BMPs (#7, page 2-21 to 2-22 and Appendix C) • Restoration of landings and heavily used skid trails

All Action Alternatives would meet all Forest Plan management direction and Regional Soil quality standards and guidelines post treatment (Appendix D). This is shown in the effects analysis and through the results of monitoring previous projects similar to the proposed treatments (page 3-108 and Appendix F).

IV. EFFECTS OF ALTERNATIVE D ON SOIL QUALITY – NO ACTION

A. DIRECT AND INDIRECT EFFECTS OF ALTERNATIVE D – NO ACTION ON SOIL QUALITY

A No Action scenario provides a baseline to evaluate the effects of the Action Alternatives. The effects on soils are discussed as changes over time on soil productivity and soil erosion.

Soil Productivity Doing nothing would not cause short-term effects on the soil resource over and above the existing condition. No additional thinning, fuels reduction, prescribed burning, or road management activities would disrupt the natural soil processes.


Additional soil compaction, rutting, puddling, or soil displacement would not occur with the No Action alternative. Soils that are undisturbed would remain so and would gradually recover.


With no action, all standing dead trees would eventually fall over and contribute coarse woody debris. Needles and branches would remain on the site and fall to the ground. Soil organisms would decompose the organic materials thus adding humus to the soil. Nutrients associated with this material would slowly become available for plant growth. As the tree canopies close in and shade the soil surface, decomposition rates would slow, allowing organic matter and nutrients to accumulate on the soil surface. This process would continue until another major disturbance such as fire or a windstorm opens the tree canopy and speeds up the recycling process again. If a fire burns hot enough and severe enough it could remove the majority of organic material and could cause widespread nutrient loss through volatilization, and erosion.

Soil Organisms

Soil microorganisms are mobile. Thus their loss is not permanent. As minor natural disturbances occur soil organisms will continue to move from undisturbed sites to disturbed sites.


These processes would continue until another major disturbance such as fire occurs in the area. If severe enough it could remove the majority of organic material and if a fire burns hot enough could cause widespread nutrient loss, hydrophobicity, and soil loss. If this were to occur soil organisms might be reduced and in some cases lost for a period of time.

Soil Erosion With no action as long as adequate vegetative cover protects the soil surface, erosion will not be a concern. However, as major disturbances occur and changes the vegetative cover erosion may become more noticeable and an issue. This would especially true if a major fire were to occur over a large area. As a fire burns hotter and consumes more vegetative material there is a higher likelihood of bare soil, hydrophobicity, and potential erosion.

Mass Failure / Soil Stability Mass failure and soil stability will continue to be minor issues with no action alternative. Natural occurring instances of soil instability may take place from time to time but as long as adequate vegetative cover is maintained these should not be large-scale features or frequent occurrences. B. CUMULATIVE EFFECTS TO SOIL QUALITY FROM ALTERNATIVE D

NO ACTION Future grazing management, dispersed camping, recreation, and firewood gathering may continue to impact soil condition. Some impacted areas may improve while other different areas may receive new impacts. Based on existing condition and monitoring, these impacts are expected to be less than three percent of an activity area. Fire suppression may indirectly cause fuels to accumulate in the proposed treatment areas. Future wildfires that are not successfully suppressed may burn in some stands at a higher than typical intensity, causing more detrimental soil disturbance. High, prolonged heat can cause physical, chemical, and biological changes to the soil that reduce soil productivity. Without fire, soil productivity would remain stable as organic matter is contributed to the soil. C. REQUIRED DISCLOSURES FOR ALTERNATIVE D

NO ACTION Irreversible/Irretrievable Commitments of No Action Alternative Irreversible commitments are permanent. No irreversible commitments are identified. Irretrievable commitments are temporary. Please see the section above on direct and indirect effects of the No Action alternative for temporary effects.


Unavoidable Adverse Effects of No Action Alternative Please see discussion above.

Forest Plan Consistency of No Action Alternative All Forest Plan management direction would be met by the No Action alternative. D. CONCLUSIONS FOR ENVIRONMENTAL CONSEQUENCES OF NO

ACTION ALTERNATIVE The soil analysis indicates that the No Action alternative would not create additional detrimental soil conditions due to management actions. Soil quality and soil productivity meet Forest Plan and Regional Soil Quality Standards.

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SECTION 3.3 SOILSa123.g.akamai.net/7/123/11558/abc123/forestservic... · Section 3.3 – Soils 3-98 SECTION 3.3 SOILS_____ I. INTRODUCTION Vegetation management activities that can