The Rim Fire Recovery Project 

Soil Report 

August 20, 2014 

Soil Scientist 

Eldorado National Forest 
Rim Recovery Soil Report

2

Introduction

This section describes the regulatory framework that applies to management of soil resources on 

Stanislaus National Forest System lands and analyzes effects to these resources associated with the 

alternatives proposed by the Rim Fire Recovery Project. Soil quality indicators are analyzed to assess 

project effects on soil productivity and soil hydrologic functions. Several soil quality measures have been 

developed to support analysis of these indicators, including effective soil stability and soil cover, porosity 

(compaction) surface soil organic material (includes displacement), soil organic matter and hydrologic 

function. The geographic scope of the soil quality analysis is generally limited to the footprint of the 

proposed vegetative treatment units. Changes to soil productivity are not expected to occur outside of the 

proposed treatment units except in landings located near proposed treatments. To a limited extent, effects 

associated with changes to soil hydrologic function could potentially extend outside of the units and is 

analyzed in the Watershed Report for the project.

Analysis Framework: Statute, Regulatory Environment, Forest Plan and 

Other Direction

The Rim Fire Recovery Project is designed to fulfill the management direction specified in the 1991

Stanislaus National Forest Land and Resource Management Plan (STF LRMP) (USDA 2010), as 

amended by Sierra Nevada Forest Plan Amendment (SNFPA) Final Supplemental environmental impact 

statement (FSEIS) and Record of Decision (ROD) (USDA 2004).

Direction Relevant to the Project as it Affects Soil Resources 

National Forest Management Act (NFMA) of 1976 (which amended The Forest and 

Rangeland Renewable Resources Planning Act of 1974)

As described in Forest Service Manual Chapter 2550 (USDA, 2010), this authority requires the 

maintenance of productivity and protection of the land and, where appropriate, the improvement of the 

quality of soil and water resources. NFMA specifies that substantial and permanent impairment of 

productivity must be avoided.

Stanislaus National Forest Land and Resource Management Plan (LRMP) 

Forest Plan standards and guidelines provide the relevant substantive standards to comply with NFMA. 

The 2010 LRMP (USDA, 2010) establishes standards and guidelines to prevent significant or permanent 

impairment of soil productivity, including: 

• Forest projects and activities shall be conducted to maintain or improve soil productivity (36 CFR 

219.27(a)(1), 219.27(a)(2), 219.27(b)(5), 219.27(f)). Forest Soil Quality Standards and Best 

Management Practices will be implemented. 

o Soil properties or conditions should not be altered to the degree that it would result in a 15 

percent or more reduction in inherent productivity potential of the soil. 
Rim Recovery Soil Report

3

 Soil Cover: Manage soil cover to avoid a High Erosion Hazard condition, as defined 

by the R-5 Erosion Hazard Rating (EHR) method (USDA FSH 2509.22, 1990). Soil 

cover should be in place prior to seasonal precipitation. 

 Soil Porosity: Maintain soil porosity above 90 of its natural condition on at least 85% 

of a treatment unit or activity area (90 percent where aerial logging systems are 

used). Plantable landings and skid trails will be tilled if compacted. Standard does not 

apply to system roads, administrative sites, or livestock driveways and bedding 

grounds. 

 Surface Organic Matter: Provide for a mix of duff, small woody debris less than 3 

inches in diameter, and large woody debris, mostly decaying and unmerchantable

logs (minimum 5 logs per acre), represents a range of decomposition classes as 

defined in the Soil Management Handbook, FSH 2509.18, Chapter 2. Standard may 

be waived in fuel break areas where fuel loading would be a safety hazard. 

 Soil Organic Matter: Maintain topsoil organic matter to at least 85% of its original

total in the top 12 inches. Applies to areas dedicated to growing vegetation. Stockpile 

topsoil to rehabilitate disturbed areas such as borrow pits, mined areas, material 

storage sites, etc. 

 Best Management Practices (BMPs): Implement BMPs to mitigate environmental 

impacts of erosion, compaction, and soil displacement. Require special soil 

mitigation to use ground skidding equipment on slopes steeper than 35%. Require 

special soil mitigation to use ground skidding equipment on soils that erode, displace, 

or compact easily. Where actual or potential slope instability is identified, specific 

mitigating measures will be developed by an interdisciplinary team including a 

geologist. 

• Design and implement management practices that maintain or improve soil hydrologic function and 

soil environmental health. 

o Soil Hydrologic Function: Infiltration and permeability are not reduced to ratings of 6 of 8 as 

defined in Region 5 Erosion Hazard Rating System (Chapter 50, R-5 FSH 2509.22). 

o Soil Environmental Health: Soil reaction class, buffering or exchange capacities, or biological 

populations are not altered to the degree that significantly affect soil productivity, soil 

hydrological function, or the health of humans and animals. Develop local threshold values 

and submit to Regional Forester for standardization among forests. 

National Forest Service Manual for Soil Management 

Forest Service Manual 2550 (USDA, 2010) establishes the management framework for sustaining soil 

quality and hydrologic function while providing goods and services outlined in Forest land and resource 

management plans. Primary objectives of this framework are to inform mangers of the effects of land 

management activities on soil quality and to determine if adjustments to activities and practices are 
Rim Recovery Soil Report

4

necessary to sustain and restore soil quality. Soil quality analysis and monitoring processes are to be used 

to determine if soil quality conditions and objectives have been achieved.

Forest staff is to determine soil quality indicators and measures that are appropriate for the proposed 

activities. Most soil quality indicators are observations and measurements taken at the soil surface and in 

the upper mineral soil since this region of the soil profile strongly influences soil hydrology and long term 

soil productivity. Forest staff is directed to estimate the type, amount, and degree of change to soil 

indicators that the proposed activity may produce by using appropriate analysis methods, scientific 

literature, past monitoring results, and knowledge of local site and soil characteristics. In most cases, 

qualitative estimates of the effects of management activities on soils are considered sufficient to meet 

analysis objectives.

The major objective of soil quality monitoring is to ensure that ecologically sustainable soil management 

practices are applied. Soil quality monitoring is to be used to validate and refine management decisions. 

Monitoring information collected allows land managers to determine if land management plan desired 

conditions are being achieved. The focus of project level monitoring is observation and documentation of 

the implementation of soil protection prescriptions.

Region 5 National FSM Supplement for Soil Management 

Region 5 FSM 2500 chapter 2550 Supplement (USDA 2012a) establishes soil functions (support for plant 

growth (productivity) function, soil hydrologic function, and filtering and buffering function) that the 

region will use to assess soil conditions. The analysis standards are to be used for areas dedicated to 

growing vegetation. They are not applied to lands with other dedicated uses, such as system roads and 

trails or developed campgrounds.

Region 5 2011 Amendment to the Forest Service Soil and Water Conservation 

Handbook

The Pacific Southwest Region (Region 5) of the USDA-Forest Service has recently adopted an 

amendment to the Forest Service Handbook, Section 2509.22, Chapter 10 (Water Quality Management 

Handbook) (USDA 2011). This handbook improves and replaces the BMPs presented in Water Quality 

Management for Forest Service Lands in California. The Forest Service water quality protection program 

relies on implementation of prescribed BMPs. These best management practices are procedures and 

techniques that are incorporated in project actions and have been determined by the State of California to 

be the most effective, practicable means of preventing or reducing the amount of pollution generated by 

nonpoint sources to a level compatible with water quality goals. Improvements to Forest Service BMPs, 

as presented in the 2011 Handbook amendment, include more detailed descriptions of individual BMPs 

(section 12), a requirement that site-specific BMPs be included in timber sale contracts (section 13), and 

direction that legacy sites (sites disturbed by previous land use that is causing or has potential to cause 

adverse effects to water quality) within timber project boundaries will be restored or improved. 
Rim Recovery Soil Report

5

Additionally, the 2011 Handbook amendment establishes an expanded water quality management 

monitoring program (section 16). BMPs were developed by watershed specialists and included in detail in 

the Watershed Report.

National Best Management Practices

In addition to BMPs prescribed in the Region 5 amendment to the Forest Service Handbook, BMPs 

presented in National Best Management Practices for Water Quality Management on National Forest 

System Lands (USDA 2012b) are also applicable to activities proposed in the Project and are also 

included in detail in the Watershed Report.

Effects Analysis Methodology

Geographic and Temporal Bounds

The scope of the analysis for direct and indirect effects to the soil resource for all proposed activities is 

limited to the proposed treatment units and connected actions situated outside of the treatment units that 

are used to support the harvest and related activities, hazard tree removal and temporary roads. Table 1 

lists activities expected to affect the soil resources.

Table 1. Activities expected to affect soil resources with each Alternative

Activity Alternative 1 Alternative 3 Alternative 4

Tractor Harvesting (acres) 24,127 26,252 24,176

Skyline Harvesting (acres) 1,253 1,096 1,066

Helicopter Harvesting (acres) 2,930 3,035 2,568

Tractor/Skyline (acres) 16 16 16

Roadside Hazard Tree Removal (acres) 16,315 15,253 15,692

Watershed Treatment, mastication (acres) 0 1,215 1,215

Watershed Treatment, mastication pre-activity (acres) 0 93 93

Watershed Treatment, drop and lop (acres) 0 2,228 1,798

Total (acres) 44,641 49,188 46,624

Temporary Roads, new (miles) 3.9 9.5 8.4

Temporary Roads, existing (miles) 9.3 22.7 22.1

Temporary Roads, revert to existing (miles) 8.4 3.3 3.3

Total (miles) 21.6 35.5 33.8

The current soil conditions observed reflect the cumulative effects of past activities, regardless of when 

they took place, so there is no definite time frame or limit for the analysis. For example, if multiple 

activities have occurred in a given treatment unit over the past 50 years, it is not necessarily possible to 

separate the effects of older treatments from more recent ones. As a result, it is not practical to set a time 

constraint on those effects. The future timeframe for the soils analysis must extend until the resource has 

recovered from the impact of the proposed activities. The persistence of soil effects into the future can 

vary widely. For example, soil cover may recover within one to three years following a treatment. Soil 

compaction effects, however, may last for decades (Poff, 1996).
Rim Recovery Soil Report

6

Assumptions Specific to Soils

• Effective application of Best Management Practices for the action alternatives: In a burned soil 

environment, the natural filtering ability of the soil is greatly reduced and accelerated hillslope 

flow and erosion is expected with appropriate application of BMPs included in the project 

Management Requirements. See the Watershed Report for BMPs, monitoring requirements, and 

corrective actions.

• Modeling parameters: Because of the size of the fire, it is assumed that the parameter 

development used in erosion modeling and Erosion Hazard Rating analysis reflects site specific 

parameters. Based on the resolution of the tools used, this assumption holds for most of the 

parameters. However, the parameters based on topography add uncertainty to the models used in 

this analysis. For this reason, the erosion analysis in this report should only be used as a 

comparative tool rather than an absolute value prediction. Site monitoring during activities by 

implementation staff will verify EHRs assumptions for specific areas..

o Several assumptions were necessary for modeling of erosion and EHR analysis and 

include:

 All slopes are uniform. Generally, slopes are more complex than any modeling 

can account for. Linear mid slopes and variable bottom and top slopes based on 

the gradient of the slopes were generalized based on the slope gradient. Also soil 

cover values are assumed to be uniform over a modeled hillslope.

 The timing, intensity, quantity, and distribution of precipitation are significant 

factors in erosion and sedimentation and can be highly variable based on the type 

precipitation event, topography and elevation. This analysis assumes a uniform 

climate over the fire area based on a modeled weather station situated at 4600 

feet near the most intensely burned portion of the fire near Corral Creek. 

 The Hazard Tree portion of the project was modeled for each alternative. 

However, it is difficult to assign parameters to the intensity of this activity since 

the frequency and distribution of hazard trees is highly variable along roadways. 

Thus, even though this activity is likely to be less intense than it is in salvage 

logging units, it is conservatively assumed to be the same for this analysis

 Cover values: Pre-fire soil cover values were based on field surveys and 

remotely sensed data analysis and generalized over the fire area. It is not 

possible to know what the post fire implementation will be. For assigning postimplementation cover values, soil cover was increased in high fire intensity due 

to the expected activity fuels that will certainly be left behind after treatment. 

Cover values were decreased in low to moderate fire intensity. Although activity 

fuels in the moderate and low fire intensity areas will also increase, machine 

piling and prescribed fire to achieve fuels objectives will likely decrease soil 

cover compared with pre-salvage values.
Rim Recovery Soil Report

7

 In Alternatives 3 and 4, Management Requirements prescribe a cover value of 

50% or greater in the areas identified as sensitive for soils and hydrology during 

the development of the proposed project; for this project analysis termed 

Watershed Sensitive Areas (WSA). Therefore the Water Erosion Prediction 

Program (WEPP) and EHR are modeled with a minimum of 50% cover in those 

alternatives. However, some of the areas may not have enough standing material 

to achieve 50%. Also, for fuel objective to be met, ground fuels cannot exceed 

20 tons/acre. Depending on the average diameter of the downed material, it may 

not be possible to achieve 50% soil cover and less than 20 tons/acre. In 

Alternative 1, increases in soil cover were anticipated to be slight do to activity 

fuels, however cover is not expected to approach 50% in these areas. 

• Approximately 4300 acres of aerial mulch treatments were applied as part of the Burned Area 

Emergency Response implementation at a rate of up to 1.5 tons/acre and 100% soil cover. Most 

of these treatment acres were applied to areas designated in Alternatives 3 and 4 as sensitive areas 

(WSAs) by the soil scientist and hydrologist that will require efforts of 50% cover post 

implementation of salvage activities to mitigate effects of the harvest in addition to the Rim Fire. 

During analysis, the conservative assumption was made that no mulch would remain at the time 

of implementation or after. This likely will not be the case, but there will be decomposition and 

incorporation depending on soil moisture and intensity of equipment use.

• Soils that burned with high severity experienced enough heat penetration that enough combustion 

of soil organic matter occurred to be equivalent of soil displacement.

•

Data Sources

Soil Data

• Spatial and Tabular Data: Soil spatial data and soil property tables were acquired from the 

Natural Resources Conservation Services (USDA 2008). This data is the correlated data derived 

from the Stanislaus National Forest Soil Survey.

• Soil Interpretations: Soil interpretations were provided by the Region 5 Soil Interpretation Guide 

(USDA 1999)

• Soil Burn Severity (Appendix B): The Soil Burn Severity and information regarding post-fire 

soil conditions was provided by Rust et. al. (2012).

Remotely Sensed Data

• Vegetation Burn Severity Map (Appendix C): produced by the Remote Sensing Application 

Center based in Salt Lake City, Utah

• LiDAR(Appendix D for example): high resolution digital elevation model acquired and processed 

by the Forest Service Remote Sensing Lab based in McClellan, California. 
Rim Recovery Soil Report

8

• Multi-Spectral Imagery (Appendix D for example): high resolution satellite data acquired and 

processed by the Forest Service Remote Sensing Lab based in McClellan, California.

Map Base Layers: 

All map base layers, 10 meter Digital Elevation Model, and vegetation information was provided by the 

Stanislaus National Forest GIS staff.

Soil Quality Functions and Indicators 

For this soil analysis, Forest Service staff has developed soil quality functions and indicators that are 

appropriate for the proposed activities site conditions, and soil characteristics of the project area. Soil 

quality functions analyzed support plant growth function (soil productivity) and soil hydrologic function. 

Soil filtering and buffering function is the function of immobilizing, degrading, or detoxifying chemical 

compounds or excess nutrients. Because no activity is proposed that would affect the soil filtering or 

buffering capacity of the soil, they are not analyzed in detail.

Soil quality indicators have been developed to support analysis of these functions. While qualitative 

estimates of the effects of management activities on soils are generally considered sufficient to meet 

project analysis objectives, quantitative field survey results and remotely sensed information were used to 

describe the existing condition and to support the analysis of effects of management activities.

Soil Productivity

Soil productivity is the inherent capacity of a soil 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 (USDA 2010). The soil stores water, nutrients, and 

provides favorable habitat for soil organisms which cycle nutrients. Chemical, physical, and biological 

soil processes sustain plant growth which provides forage, fiber, wildlife habitat, and protective cover for 

watershed protection (USDA 2012a). Important measures of soil productivity include: soil cover, soil 

porosity, and surface organic matter.

Soil Productivity Indicator 1: Soil Stability and Effective Soil Cover

An adequate level of soil cover is needed to maintain soil stability and prevent accelerated erosion. 

Effective soil cover consists of low-growing vegetation (grasses, forbs and prostrate shrubs), plant and 

tree litter (fine organic matter), surface rock fragments, and may also include applied mulches (straw or 

chips). Effective soil cover is the most important soil property in maintaining soil stability and reducing 

erosion. Surface cover mitigates erosion primarily by intercepting and reducing the detachment energy of 

raindrops, improving soil porosity, preventing soil sealing, and increasing surface roughness (Larsen et. 

al. 2009).
Rim Recovery Soil Report

9

Ground cover protects soil from rainsplash erosion, 

slows surface runoff, and filters runoff. The percent 

bare soil is an important control on sediment production 

following timber salvage (Chase 2006). The presence 

of even a thin litter layer can substantially reduce soil 

erosion (Peterson 2009). Soil cover is the dominant 

control on post-fire sediment yields and generally does 

not begin providing protection to soil stability until a 

level of 50% is reached (Larsen et. al. 2009). Figure 1 illustrates from Pannkuk and Robichaud (2003) 

the coverage of 50% ponderosa pine needles.

Desired conditions for soils from FSH 2550 are that “an adequate level of soil cover is maintained to 

prevent accelerated erosion, and erosion prevention measures are effectively implemented following soil 

disturbing activities. Generally on slopes less than 35%, a minimum of 50% soil cover in a well 

distributed pattern is needed to maintain soil stability. Greater amounts of soil cover are generally needed 

for steeper slopes and in riparian zones.

Effective soil cover was estimated in field surveys. The field collected information was used to correlate

existing and potential soil cover with high resolution satellite imagery. The Erosion Hazard Rating (EHR)

(USDA 1990) system and the Water Erosion Prediction Program (WEPP) (Elliot 2010) were used to 

identify areas where accelerated erosion is likely to occur and to estimate the effects that management 

activities would have on erosion. 

Metrics for Indicator 1 are erosion rates as modeled by WEPP, erosion hazard as measured by EHR, and 

Effective Soil Cover. Table 5 summarizes the indicators for the existing condition for each alternative. A 

soil will be considered stable if EHR ratings are moderate or below, and soil cover values are greater than 

50%. Although threshold values for erosion rates are not established in Management Direction, this 

analysis uses the assumption that a soil is stable if erosion rates do not exceed rates of formation. The Tfactor rating is an interpretation of acceptable soil loss (tons/acre/year) which is related to the soil rate of 

formation. This interpretation is provided by the NRCS. Values for the soils within the fire area range 

from 1-5 tons/acre/year with 1 ton/acre equivalent to 2 sheets of paper.

Soil Productivity Indicator 2: Surface Organic Matter: 

The concept of surface organic matter is related to effective soil cover, but includes the quality of the 

material. The amount of organic material on top of the mineral soil is maintained at levels to sustain soil 

microorganisms and provide for nutrient cycling. The size, amount, and distribution of organic matter 

maintained on the mineral soil on a long-term basis is consistent with the amounts that occur given the 

local ecological type, climate, and normal fire return interval for the area. Surface organic matter is 

characterized by its level of decomposition; Oi is fresh material with no decomposition, Oe is organic 

Figure 1. 50% soil cover ponderosa pine (Pannkuk 2003)
Rim Recovery Soil Report

10

material with intermediate decomposition, and Oa is highly decomposed organic material with the 

original structure (needles and leaves) no longer discernible. The importance of the surface organic matter 

is comprehensively reviewed by Neary et al. (2005). Generally surface organic matter is important for 

moisture retention, nutrient cycling and storage, soil stability, infiltration, thermal cover, soil fauna and 

flora habitat, and gas exchange. Effective cover analyzed as Indicator 1 can be any material that provides 

for soil stability and does not factor in the quality of the cover to soil function. For example, although the 

organic layers are consumed by fire, needle cast additions can improve effective cover while taking years 

to incorporate into the soil as organic matter 

Greater amounts of soil cover are generally needed for steeper slopes and in riparian zones (USDA, 

2012a). Field crews collected data on the quantity and quality of soil cover and logs on the ground. 

Although the quantity and quality of surface organic material is unknown prior to the fire, field 

observations related to the Vegetation Burn Severity Map (Figure 1.04-2) allows for a good correlation of 

existing and potential cover as related to the canopy change caused by the fire. To estimate surface 

organic material, it is assumed that the amount of heat in both the moderate and high soil burn severity 

areas incinerate enough surface organic material to affect the soil productivity of these areas.

Soil Productivity Indicator 3: Soil Organic Matter.

Soil organic matter, also known as soil humus, is the highly decomposed organic material that is 

incorporated into the mineral portions of the soil. Soil organic matter is important for holding soil water, 

cycling nutrients, and reducing soil strength. The amount of organic matter within the mineral soil, 

indicated by the color and thickness of the upper soil horizon, is within the normal range of characteristics 

for the site, and is distributed normally across the area. The upper soil horizon is not displaced or eroded 

to the degree or extent that soil productivity is decreased for the desired vegetation.

Impacts to soil organic matter generally come from both excessive soil heating and soil displacement 

from mechanical disturbances. Soil heating volatizes both the complex organic compounds and plant 

nutrients. Changes in the soil organic matter can affect soil nutrient cycling, water holding capacity and 

aggregate stability.

Metrics for soil organic matter (SOM) is the extent of soil depleted either by volatilization from fire or

displaced by project activities. Soil burn severity ratings of high were used to determine where SOM was 

volatized during the fire. High soil burn severity usually indicates penetration of heat into the soil and the 

consumption of fine roots and soil organic matter. This indicator was not directly measured by field 

crews, but was evaluated by the soil assessment team during BAER operations to develop the soil burn 

severity map. An analysis of existing and potential skid trail locations was used to identify areas where 

mechanical displacement of the SOM was likely. To survey the amount of existing disturbance within 

units, hand-digitizing of all disturbances based on LiDAR was completed. 
Rim Recovery Soil Report

11

For the purpose of this analysis, detrimental soil displacement is defined as occurring when either 2 

inches or 1⁄2 the total thickness (whichever is less) of the humus-enriched topsoil (A horizon) is removed 

from an area of 3 square feet or larger.

Indicators 4: Soil Porosity 

Soil porosity is the volume of pores in a soil that can be occupied by air, gas, or water and varies 

depending on the size and distribution of the particles and their arrangement with respect to each other. 

The two primary mechanisms for reducing soil porosity are compaction and soil sealing. The use of heavy 

forestry equipment and frequent stand entries increases bulk density and decreases the porosity of soils, 

which increases the potential for detrimental compaction (Powers et al 1998). Soil sealing is the process 

after a fire where fine soil particles fill the soil pores and reduce the flow of water through the voids.

The degree and extent of susceptibility to compaction is primarily influenced by soil texture, soil 

moisture, coarse fragments, depth of surface organic matter, ground pressure weight of the equipment, 

and whether the load is applied in a static or dynamic fashion. Soil compaction and increased soil strength 

can cause slowed plant growth, impeded root development, poor water infiltration, restricted percolation, 

increased overland flow during high precipitation events, and can cause plant nutrients to be relatively 

immobile or inaccessible (Poff, 1996). Recent research suggests that the effect of severe compaction on 

biomass productivity is highly dependent upon soil texture (Powers et al 2005). Within the Rim Recovery 

project area, soil textures of loam and clay loam produce widespread severe compaction ratings (Table 2).

The extent of detrimental soil compaction should not be of a size or pattern that will result in a significant 

change in production potential and should not result in common occurrences of overland flow and erosion 

within treated units (indicating that the infiltration and permeability capacity of the soil has been 

exceeded for the local climate).

Soil sealing and water repellency (hydrophobicity) resulting from a fire also affects area soil hydrologic

function. As summarized by Larsen et al. 2009, soil seals are a thin layer of dense soil at the mineral soil 

surface. Metrics for soil porosity is the amount of ground that was impacted by logging equipment and 

high soil burn severity with the assumption that primary and secondary skid trails will be decompacted 

with subsoilers or ripping shanks. Compaction was identified by field crews using an evaluation of soil 

structure, particularly platey structure. Field observations were then used to correlate disturbances 

identified using the same methodology used to identify displacement. Soil sealing, evaluated using soil 

burn severity, is likely to occur where ratings are high. The amount of existing disturbance within units is 

estimated using the LiDAR data set; however, this indicator is discussed qualitatively.

Methodology for Soil Resource Analysis

The following section is a summary of the methods used to document and analyze the affected soil 

environment and the effects of proposed activities. A detailed description of the analysis methods can be 

found in Appendix D of this report. 

Soil Description and Interpretation
Rim Recovery Soil Report

12

Soils information for this analysis was derived from Stanislaus National Forest Soil Survey and obtained 

from the Natural Resources Conservation Services (NRCS) Soil Data Viewer (SDV). The SDV provided 

both spatial and soil property information for both field survey and analysis.

There were 67 soil map units within the fire area. Because of the size of the fire, a soil map was 

generated and analysis was completed based on dominant soil series and closely related soils series in a 

map unit. A soil map unit is a collection of areas defined and named the same in terms of their soil 

components (e.g., series) or miscellaneous areas or both. Soil series are families of soils having similar 

profiles, and developing from similar original materials under the influence of similar climate and 

vegetation. The soil map is included in Appendix A and a table of soil percentages and relevant soil 

properties used in analysis is included in Table 2.

Site Observations

In the fall of 2013, specialists from multiple resource disciplines assessed soil condition measures within 

the fire boundary. The goals of field observations were to identify soil properties useful in confirming the 

accuracy of the soil survey and to identify existing soil conditions to help analyze cumulative effects and 

understand soil response to management. Field observations were also important to correlate the site 

conditions to remotely sensed data.

Site observation methods were developed for rapid assessment by field crews. Plot selection was 

stratified based on burn severity, soil type, topography, and visual satellite imagery expression. Site 

specific information collected by crews or remotely sensed in GIS included topography, soil physical 

properties, existing disturbance, and existing and potential soil cover. Ninety-seven plots were recorded.

Remotely Sensed Data Analysis

Analysis for this project utilized several remotely sensed sources of information to identify areas of soil

and vegetation burn severity, tree mortality, disturbances, and potential and existing covers. Unit-by-unit 

ocular analysis was completed the remotely sensed data sets. 

Erosion Modeling

The Water Erosion Prediction Program (WEPP) Disturbed WEPP batch program (Elliot 2010) was used 

to model predicted sedimentation resulting from the Rim Fire, salvage activities, and watershed 

treatments. Disturbed WEPP estimates erosion on an annual basis in contrast to WEPP ERMiT which is a 

storm driven model that is useful during the Burned Area Emergency Response (BAER) assessment. 

WEPP is a physically based erosion model which incorporates topography, soils, climate, vegetation and 

management activity. Because of the size and complexity of the fire, modeled erosion outputs should not 

be used as absolute values. The purpose of using modeled values is to illustrate relative risk from existing 

and management activities and to evaluate the relative change in sedimentation associated with proposed 

activities. Three batch models were created to model post-fire (existing condition), identified watershed 

sensitive area treatments, and salvage logging effects not within identified watershed sensitive areas. 
Rim Recovery Soil Report

13

Soil Erosion Hazard Ratings

The Region 5 Soil Erosion Hazard Rating System (USDA 1990) was used to rate the risk of soil erosion 

for all soils in the project area post fire, post implementation and incorporating watershed treatments. 

This system uses various physical soil properties along with climate and site-specific conditions to rate 

soils for hazard of sheet and rill erosion. For the Erosion Control Plan, Appendix E summarizes those 

units where EHR exceed a Moderate rating in greater than 15% of the unit.

Watershed Sensitive Areas

Watershed staff examined each unit of the alternatives for areas considered Watershed Sensitive Areas. 

Watershed Sensitive Areas are portions of the watershed that are at high risk of soil erosion and 

sedimentation due to the combined effects of the Rim Fire and potential recovery activities. Criteria for 

evaluating the existence of WSAs include: proposed recovery activities, burn severity including existing 

and future soil cover, topography including percent slope, slope shape, and slope length, proximity to 

intermittent and perennial drainages, and proximity to high runoff response soils.

Affected Environment

The Rim Fire started on August 17, 2013 in a remote area of the Stanislaus National Forest near the 

confluence of the Clavey and Tuolumne Rivers about 20 miles east of Sonora, California. Over the next 

several weeks it burned 256,283 acres, or about 400 square miles. The burned area within the forest 

boundary was 176,768 acres, including 22,340 acres of private land, for a total of 69% of the fire area. 

The remaining 31% occurred to the east in Yosemite National Park. (Fire acreage varies slightly by 

mapping or reporting sources).

The Rim Fire was the third largest wildfire in California history and the largest wildfire in the recorded 

history of the Sierra Nevada mountain range. It was also the largest forest fire, burning across a massive 

conifer dominated landscape. The two fires with more acreage were wind driven brush fires, near San 

Diego and in the northeast corner of California. 

CLIMATE

Climate in the Rim Fire Recovery project area consists of warm, mostly dry summers and cool, wet 

winters. Precipitation increases in elevation, with a range of about 30 to 50 inches per year across the fire 

area. Annual variation in precipitation can vary up to about 50 to 150% of average depending on wet or 

dry years. About 80% of the annual precipitation occurs from November through March. Rain dominates 

areas below about 4,000 feet though occasional snow occurs in the coldest months. Between 4,000 and 

5,000 elevation feet rain and snow is mixed, and above 5,000 feet snow is more common across the 

landscape. Warm frontal storms can raise snow levels to 7,000 feet or higher. The climate effects on post 

fire or management erosion is highly variable and dependent on the intensity and duration of the storms. 

Even though modeling in this analysis assumes a 5 year average precipitation year, the topographic relief 
Rim Recovery Soil Report

14

of the Sierra Nevada mountain range can generate extreme localized weather events. A fire the size of the 

Rim Fire can experience drastically different weather patterns within the fire perimeter during the same 

precipitation event.

GEOLOGY

The Rim Fire project area includes all three of the principal geologic types in the Sierra Nevada mountain 

range. Metamorphic rock occupies much of the lower elevations and the Sierra granitic batholith and relic 

volcanic flows generally occur at higher elevations. 

The main geomorphic feature in the project area is the Tuolumne River canyon, which has carved an eastwest chasm about 2,500 to 3,000 feet deep through the entire length of the fire area. The adjacent Clavey 

River has a similarly deep canyon in its lower reaches. The Jawbone Lava Cap lies atop the broad east 

ridge of the lower Clavey River, a remnant of an ancient lava flow that originated east of the Sierra 

Nevada mountain range prior to the Sierra uplift about 10 million years ago. North of the Tuolumne 

canyon the watersheds gradually rise to about 6,000 feet from Duckwall Mountain on the west to Woods 

Ridge on the east, near Cherry Lake. The landscape climbs to almost 7,000 feet west of Cherry Lake. 

Glaciation is another striking geomorphic feature in some eastern locations of the Rim Fire. Glacial 

periods up to about 90,000 years ago have scoured the upper portions of Tuolumne River canyon as well 

as Cherry and Eleanor Creeks. Remnant small glaciated alluvial deposits are found in some stream valleys 

in the fire area down to about 4,500 feet. 

FOREST VEGETATION

Vegetation is important for soil development, proper soil function, and soil protection. It shades soil to 

hold moisture, it is vital to the nutrient cycle, and provides cover that minimizes erosion. Mixed conifer 

and true fir are the two most common forest types present within the analysis area and because of the rich 

fire history within the perimeter of the Rim Fire, there are many shrub and hardwood stands intermixed 

within the forest communities. Within the project area, proposed treatments are primarily located in areas 

that have been substantially burned in order to recover the value of fire-killed trees. The Rim Fire had a 

substantial effect on the forested communities. Approximately 75% of the vegetation in areas proposed 

for treatments are burned with moderate or high vegetation burn intensity. As discussed in the Vegetation 

report for the project, the ability of forests to regenerate after stand replacing fire is highly dependent on 

seed sources. Natural seedling regeneration is more likely to occur and dominate in the mixed severity 

patches of fire and closer to the edge of high severity patches. The percent of grasses, forbs and brush 

within in the Rim Fire is expected to increase as fire severity increased. Therefore in areas of the fire 

where shrub development is rapid, it is expected that shade dominate trees and brush will likely be the 

dominant vegetation types into the future. 
Rim Recovery Soil Report

15

Existing Soil Condition

Soils within the project area are primarily derived from metamorphic rock in the lower elevations and the 

granitic rock at mid and higher elevations. A soil map can be found in Appendix A and Table 2 displays

the proportion of general soil groups per alternatives and the corresponding soil properties used in the 

analysis of this report. Field work during the BAER assessment and for this project verified the existing

soil survey information, investigated current soil conditions and effects of the fire, and management 

capabilities. 

The dominant soils within the analysis area are mostly loams, sandy loams, and loamy sands with 

gravelly to extremely gravelly texture modifiers, indicating high natural infiltration rates, and high rock 

content in many areas. These soils range from shallow to deep, reflecting a wide range of soil 

productivity and soil hydrologic groups. Specific dominant soils include the Holland, Josephine, 

Wintoner, and Fiddletown. Rock outcrop is also common, even dominant, in several map units. 

Although rock outcrop does not produce sediment, it commonly produces runoff which accelerates 

erosion on soils downslope; a condition considered in the identification of Watershed Sensitive Areas.

Table 2 Soil families and associated properties used in analysis

Family

Maximum Extent 

of Activities 

(Percent of Total 

Acres)

Soil Properties used in Analysis

TFactorSurface 

Texture

Subsurface 

Texture

Soil 

Depth, 

inches

Compaction 

Hazard

Dystric Lithic 

Xerochrepts

2.1 1 Cobbly loam Cobbly 

loam 20-40 Moderate

Dystric 

Xerochrepts

0.28 1 Cobbly loam

Coarse 

sandy 

loam

20-40 Moderate

Dystric 

Xerorthents

0.6 1 Coarse sandy 

loam

Coarse 

sandy 

loam

20-40 Slight

Entic 

Cyrumbrepts

0.06 3 Coarse sandy 

loam

Coarse 

sandy 

lowam

20-60 Moderate

Fiddletown

7.5 2

Gravelly to 

Bouldery 

sandy loam

Gravelly 

sandy 

loam

20-60 Slight

Gerle

5.4 4 Gravelly 

sandy loam

Sandy 

loam

40-

60+ Slight

Half Dome

0.17 3

Very 

Bouldery 

sandy loam

Cobbly 

sandy 

loam

40-

60+ Slight

Holland 35.6 4 Loam Clay loam 40-80+ Severe

Humic 

Dystroxerepts 0.1

Josephine 27.8 4 Gravelly loam Clay loam 20-60+ Severe

Lithic 

Xerumbrepts

3.7 1 Loamy sand Sandy 

loam 0-20 Slight
Rim Recovery Soil Report

16

McCarthy 4.1 3 Gravelly sandy loam

Sandy 

loam 20-60 Slight

Pinole

0.5 4 Gravelly 

loam Clay loam 60-80+ Severe

Rock Outcrop 0.8 1 Unweathered bedrock NA 0-10 Slight

Typic 

Dystroxerepts

0.4

Ultic Haploxeralfs 1.7 1 Sandy loam Loam Severe

Wintoner

9.1 4 Gravelly loam Clay loam 40-

60+ Severe

Xerolls 0.1 5 Loam Loam 40-60+ Severe

The majority of soils (approximately 75%) within the proposed action have a severe compaction rating

(high probability to be compacted by activities when moist) and these tend to be the highest productive 

soils in the project area, particularly the Holland and Josephine soils. Both compaction ratings and 

productivity are strongly correlated with soil texture. During surveys, field crews noted severe 

compaction rating on nearly all sampled legacy skid trails sampled confirming the potential of 

compaction in the project area. 

Fire history (Table 3) and past mechanical activities (Watershed report) have had the greatest influence 

on the existing soil condition. Table 5 summarizes the existing disturbance within the maximum extent of 

activities. 

Fire History Effects on Soil

Although many activities have occurred and affected the area of analysis (See Cumulative Watershed 

Effects, Watershed Report), the existing soil condition is most dominated by recent fire history. Table 3

summarizes the six largest fires areas affecting the Rim Fire perimeter.

Table 3 Soil Burn Severity for Selected Fires in Relation to the Rim Fire

Fire Name Fire 

Year

Fire Size Soil Burn Severity

Acres within 

Stanislaus National 

Forest, Rounded

High (%) Moderate (%) Low and 

Unburned Area 

(%)

Rim 2013 154,530 7 37 56

Stanislaus Complex 1987 147,100 36 20 44

Rogge* 1996 19,400 0 41 59

Granite 1973 17,100 55 30 15

Ackerson** 1996 11,300 19 14 67

Pilot 1999 4,000 46 25 29

*There was no high soil burn severity due to low fuel loading over much of the area because of new tree plantations after the Stanislaus Complex 

fire. **This fire was much larger overall, with most acreage in Yosemite National Park.
Rim Recovery Soil Report

17

Fire can have both beneficial and negative effects on the soil resources. Soils that burn with low severity 

can maintain soil cover, mineralize important nutrients from plant matter stored on the soils surface, 

reduce fuel loads that if allowed to accumulate could cause high burn severity to the soil, and stimulate 

herbaceous vegetation which helps facilitate nutrient cycling. Moderate to high severity fires can cause a 

loss of soil hydrologic function by sealing pores and degrading soil structure, it can cause a loss of soil 

productivity by processes of erosion, mass-wasting, and nutrient volatization, and it can allow exotic 

plants to establish which can affect soil productivity.

 

Although the Rim Fire was the largest fire in Sierra Nevada recorded history, the soil burn severity was 

relatively low. The Granite, Ackerson, and Stanislaus Complex fires and post-fire fuel reduction activities 

removed significant build-up of surface fuels so the heat intensity and residence time was not favorable to 

high SBS. Table 4 indicates that the SBS as a proportion of the action alternatives is much higher than the 

fire as a whole simply because very little tree mortality occurred in the unburned and low SBS portion of 

the fire. There is very little difference in proportion of burn severity between alternatives.

Table 4 Soil Burn Severity by Alternative

Burn 

Severity

Maximum Extent of 

Proposed Activities/ acres

Maximum Extent of 

Proposed Activities, %

Unburned 3409 7.2

Low 15038 31.8

Moderate 23012 48.6

High 5858 12.4

The direct effect fires have on soils is measured by the Soil Burn Severity (SBS). Whereas fire intensity 

measures the changes to the vegetation community, SBS indicates both changes to the above ground 

material that provides both existing and future soil cover and the effects to the soil properties caused by 

heat penetration below ground. SBS categories are summarized as follows (Parsons et al., 2010):

• Low: Surface organic layers are not completely consumed and are still recognizable. Soil 

structure and roots are unchanged, and vegetation will appear green.

• Moderate: Up to 80% of the pre-fire ground cover may be consumed. Fine roots may be 

scorched but not consumed. Soil structure is not changed and there is usually potential for some 

immediate cover recruitment.

• High: All or nearly all of the prefire cover and organic matter has been consumed, Soil structure 

may be completely obliterated or strongly impaired. Fine surface roots have been consumed and 

coarse roots extending from stump holes may be consumed. There is little to no chance for shortterm cover recruitment; cover will not return until vegetation regeneration occurs and snags begin 

to fall.
Rim Recovery Soil Report

18

A map of SBS for the entire fire area along with the perimeter of past fires is found in Appendix B. For a 

more detailed narrative of the effects the fire had on the soil, see the Rim Fire BAER Soil Report (Rust et. 

al. 2013)

The Rim project area has a relatively high level of displacement because soils that burned with high SBS 

volatize the organic material in the soil that contribute to soil productivity. For the project area, the fire 

has resulted in the existing condition close to threshold values with the effects concentrated in units where 

high sbs occurred. Although displacement of soil organic matter is the combined effect of both 

mechanical disturbance and fire process, fire process is the dominant impact to soil organic matter.

Mechanical Disturbance:

Mechanical equipment used in forest management activities compresses the soil by reducing pore size. 

This reduction in the pore space and the resulting increase in bulk density reduces the water holding 

capacity and gas exchange of soils. Compaction also increases the strength of soils which restricts the 

ability of roots to penetrate the soil matrix. During post-fire field surveys, compaction was found to be the 

most severe in the Josephine and Holland soils when skid trails and legacy temporary roads were benched 

and the surface loam soils were displaced exposing the subsoil with greater clay. In most units, there is an 

extensive skidding network resulting from past timber sales (green and salvage). The extent of this 

disturbance will be evaluated in LiDAR. During field surveys, plot centers were located at skid trails so 

the severity of disturbance could be evaluated. Most skid trails sampled revealed high levels of 

compaction with little recovery. Within these skid trail prisms, soil cover generally is similar to the 

surrounding areas. Vegetation that grows on these skid trails is either very stunted or non-existent 

reflecting a reduction of soil porosity and displacement of the soil organic material.

As mentioned above displacement of soil organic matter results from the combined effect of mechanical 

disturbance and combustion in high sbs areas. Displacement from mechanical disturbance is relatively 

small compared to the effects of displacement from the Rim Fire. Without fire, the displacement and 

compaction footprint would essentially coincide.

Summary of Existing Conditions

Table 5 summarizes the existing conditions within the maximum extent of activities, which includes all 

alternatives. The existing conditions include the effects from past fire and mechanical disturbance.

Table 5 Summary of Existing Condition of Indicators

Existing Condition

Indicator Acres %

Indicator 1

Soil 

Stability, 

Erosion

Average 

Erosion Rate, 

ton/acre (1)

3.11 ----
Rim Recovery Soil Report

19

Indicator 1

Soil 

Stability, 

Erosion 

Hazard 

Rating

Greater than 

Moderate 

Rating

(acres)

10,725 23

Indicator 1 Soil Cover

Area with 

less than 

50% cover

(acres)

25,322 53%

Indicator 2

Surface 

Organic 

Material

Area with 

less than 

50% cover 

(acres)

28,870 61%

Indicator 3 Soil Organic 

Matter

Area with 

expected soil 

productivity 

loss due to 

displacement

6062 13%

Indicator 4

Area with 

expected 

soil 

productivity 

loss due to 

compaction 

or loss of 

porosity

Area with 

expected 

soil 

productivity 

loss due to 

compaction 

or loss of 

porosity

932 2%

(1) Erosion rates for unburned areas tend to be 0.5 tons/acre or less.

Indicator 1: Soil Stability and Effective Soil Cover

In areas of moderate and high burn severity, nearly all of the soil cover and ground vegetation was 

consumed resulting in a lack of soil stability. Where fire-killed needles were not consumed, heavy 

needlecast has accumulated since the fire; in most areas, 100% soil cover has been attained. Although not 

apparent during field visits in the Fall of 2013, rapid resprout of shrubs and herbaceous plant communities 

is expected in the spring on those soils that burned with a moderate or less SBS which will increase the 

soil stability. 

Soil cover was not found to correlate well with Soil Burn Severity, however, generally soil cover values 

of 5-20% for High SBS, 5-50% for Moderate SBS and 50 to 100% for Low SBS and unburnt portions of 

the fire were observed immediately after the fire. Many areas of the fire saw soil heating that consumed 

most of the ground cover but left much of the canopy killed but the needle structure left intact. When 

field surveys were conducted in the Fall of 2013, those soils situated under a forest canopy of dead 

needles were observed to have thick needle cast layers with coverage approaching 100%.

Shrubs such as bear clover, manzanita and whitethorn are likely the first vegetation that will occupy areas 

of high and moderate SBS and these shrubs typically provide good soil cover in the first 2-3 years after 

wildfire. During field surveys, the presence of bear clover was noted. Burnt above ground bear clover 
Rim Recovery Soil Report

20

was observed throughout the fire area, particularly if the pre-fire canopy was less than 50%. In isolated 

pockets of the fire, resprouting of the bear clover was evident. Research is not clear on the revegetation of 

bear clover in relationship to burn severity, but Knapp et al (2012) noted seeds have higher mortality with 

increasing soil heating. This may delay the recovery of soil stability in the areas with high Soil Burn 

Severity.

Soil cover was substantially reduced due to the Rim Fire and predicted cover values when implementation 

would occur would remain low. After winter needle cast, it is expected that 53% of the soils in the 

analysis area will have less than the 50% soil cover threshold. With a paucity of soil cover, the soils will 

lack thermal cover and are expected to dry rapidly on the surface with warm weather, particularly on 

south facing slopes. In a drought year this could lead to significant reduction of soil stabilizing root 

regrowth. The low soil cover values significantly increases the erosion risk by exposing the soil to splash 

erosion and reduce the surface roughness.

Erosion Hazard Ratings were evaluated to determine if the level of soil cover was commensurate with a 

threshold value of Moderate or less. One would expect EHR values to be above threshold values in a 

majority of the fire area, however, EHR is highly dependent on slope. Low gradient slopes need very 

little soil cover to maintain a Moderate rating. Only 23% of the maximum extent of area is considered 

above threshold values of Moderate in the existing condition. As vegetation regrowth and downed woody 

material accumulates over time, the EHR values are expected to improve.

The Erosion Hazard Rating identifies areas at risk of erosion whereas the Water Erosion Prediction 

Program identifies the magnitude of erosion. Within the analysis area, the average erosion rate was 

predicted to be 3.1 tons/acre/year. Although this is below the T-Factor value of 4 tons/acre/year rated for 

most of the soils in the project area, this is an average. Erosion rates were found to exceed 20 

tons/acre/year with areas with an SBS rating of High and on steeper ground. 

During project development, key areas were identified by watershed staff where accelerated erosion is not 

only likely to happen before and after proposed activities, but there is a high probability that soil stability 

and water quality are at risk from the cumulative impacts of proposed activities. These areas are termed

Watershed Sensitive Areas (WSAs) for the purpose of this analysis. 

Indicator 2: Surface Organic Matter

Generally speaking, the fire consumed the surface organic material to the same extent as the soil cover. 

However, the nutrient rich highly decomposed organic material was consumed during the fire in the 

‘High’ and ‘Moderate’ SBS. Even though needle cast and crown breakage is expected to accumulate on 

these areas, they are still considered deficient in Surface Organic Material. Although the thin layer of 

needlecast is crucial for soil stability, it does not have the nutrient density, soil biology, protection from 
Rim Recovery Soil Report

21

soil sealing, water holding capacity, or moderation of infiltration that decomposed soil cover provides to 

the soil. 

The consumption of the duff layers often burns in a mosaic and the extent cannot be predicted although it 

is likely to be 100% in the ‘High’ SBS and a majority in the ‘Moderate’ SBS. At most, 61% of the 

analysis area is deficient in Surface Organic Material. Levels of Surface Organic Matter should be 

relatively unchanged in the Low SBS with the lightly decomposed material primarily being consumed. 

This material is nearly recovered with needlecast. Because the Surface Organic Material generally burns 

with much less intensity in Low SBS, there is an increase in short term soil nutrients delivered to the soil. 

It is not known how much the unburned and Low SBS portion of the analysis area was deficient in this 

indicator prior to the Rim Fire. It is likely that much of these areas were depleted during the 1987 

Stanislaus Complex and the 1973 Granite Fire and by the subsequent post-fire logging and reforestation 

activities.

Indicator 3: Soil Organic Matter

Soil Organic Matter (SOM) is depleted either by mechanical displacement or through thermal 

volatilization. SOM has been displaced within the fire area but has not yet been determined. In those 

areas that were mechanically displaced, the SOM was relocated to areas outside of the mechanical 

disturbance. Although the nutrients in these displaced soils that were not burned at ‘High’ SBS still 

remain within the units, the effect is localized and may not have as great of an effect on productivity on 

the unit as much as that SOM that was lost due to the fire. In the areas of ‘High’ SBS, carbon and 

nitrogen were likely volatized. Because Surface Organic Material is not present and vegetation recovery 

is likely to be delayed, C and N recovery could take several years as the site becomes colonized with 

shrubs and herbaceous species. 

Indicator 4: Soil Porosity

The fire did not reduce porosity through mechanical compaction; however, soil sealing is a significant 

factor in reduced soil porosity. Soil sealing is the process where fine soil particles and ash fill in the voids 

that transmit water vertically. Soil sealing generally occurs where the soil structure has been 

compromised allowing individual particles of soil to be into the voids or where enough ash can fill the 

soil pores and impede infiltration. Porosity change from the fire generally occurs in the areas of ’High’ 

and ‘Moderate’ SBS, and can be assumed to coincide with those ratings. Soil sealing is expected to be a 

relatively short-lived phenomenon and will naturally decrease as vegetation re-sprouts and provides 

vertical soil pores, ash and the thin soil layer erodes, and as freeze-thaw/biological processes incorporate 

the components of the ash into the soil structure.
Rim Recovery Soil Report

22

Although the analysis area has a long history of mechanical operations, soil strength level is conducive to 

favorable rooting environment for desired plant species over the vast majority of the project area. The 

maximum extent of detrimental compaction indicated by the 2013 surveys and LiDAR analysis has not 

yet been determined The compacted areas are primarily limited to existing temporary roads, skid trails, 

and dispersed recreation sites. Designated roads and trails are not considered in the analysis. It is clear 

that many of these compacted surfaces have impaired site productivity and many of them are the source 

of accelerated runoff and erosion prior to the fire. These compacted surfaces will be significant sources 

of accelerated runoff and gully erosion in precipitation events much smaller than what would cause 

significant hillslope erosion particularly where they are situated below an intensely burned slope. Slopes 

above Granite Creek, Corral Creek, Skunk Creek, and Reed Creeks are highly susceptible to the effects of 

the compacted soil surfaces.

Overall, the maximum extent of existing reduced porosity has not yet been determined

Environmental Consequences 

Chapters 1 and 2 of the EIS provide detailed information about the design features for the Proposed 

Action alternative. All mechanical harvest operations would adhere to standards and guidelines set forth 

in the timber sale administration handbook (Forest Service Handbook [FSH] 2409.15) and the best 

management practices as delineated in the Region 5 Amendment to the Forest Service Water Quality 

Management Handbook (USDA 2011a) and the National Best Management Practices for Water Quality 

Management on National Forest System Lands (USDA 2012). Timber sale contracts contain many 

standard provisions that help ensure protection of soil and water resources. These include provisions for 

an erosion control plan, road maintenance, skid trail spacing, and restrictions for wet weather operation.

The environmental consequences section looks at the direct, indirect, and cumulative effects of the 

Proposed Action (Alternative 1), the No-Action Alternative (Alternative 2), Alternatives 3 and 4 which 

are alternatives to the Proposed Action. 

Direct and Indirect Effects.

The effects to the soil resource by activities for each alternative are compared to the threshold values 

determined by Management Direction or by thresholds used as proxy. Threshold values are:

• Indicator 1: Soil Stability, Erosion Rates: Erosion Rates that exceed the T-Factor 

(tons/acre/year). The T-Factor is considered the maximum acceptable soil loss.

• Indicator 1: Soil Stability, Erosion Hazard Rating: EHR values are ‘Moderate’ or less in 

greater than 15% of a unit area.

• Indicator 1: Soil Cover: Soil cover values are at least 50% over 85% of a unit area.

• Indicator 2: Surface Organic Material: Duff layers are intact over at least 85% of an area.
Rim Recovery Soil Report

23

• Indicator 3: Soil Organic Matter: Where a minimum of 85% of the top 12 inches of soil is 

maintained over at least 85% of a unit. Soil Burn Severity and mechanical disturbance extent 

is used as a proxy measure for this indicator.

• Indicator 4: Soil Porosity: Soil porosity will not be reduced by 10% in areas greater than 

15% of a unit. Although porosity is not practical to measure, soil strength, root vigor, soil 

structural change and remotely sensed analysis is used as a proxy to determine the extent of 

soil porosity change great enough to reduce soil productivity.

The analysis of effects is limited to the proposed activities that are expected to change the values of the 

indicators as compared to the existing condition. Although many unknowns exist both in existing 

conditions and the intensity of the activities on a site specific area, conservative estimates were made 

which would likely overestimate the effects of the activities. By comparing the activity effects to 

threshold values, this analysis informs the decision maker of the relative risk each alternative has to the 

threshold values established in management direction. Road construction and rock quarry work would 

permanently remove those areas from soil productivity. Management direction is to analyze for impacts to 

soils for areas of soil function. Due to implemention of BMPs those activities are expected to result in 

effects that are limited in extent to those specific locations and are therefore not expected to significantly 

impact soil productivity in the project area. Activities analyzed include tractor logging, skyline logging, 

helicopter logging, road work, prescribed fire, watershed treatments, hazard tree removal along level 2 

roads, and Best Management Practices which would be implemented to maintain watershed health.

Cumulative Effects

When analyzing for cumulative effects, this analysis relies on current environmental conditions as a proxy 

for the impacts of past actions. This is because existing conditions reflect the aggregate impact of all 

prior human actions and natural events that have affected the environment and might contribute to 

cumulative effects.

This cumulative effects analysis does not attempt to quantify the effects of past human actions by adding 

all prior actions. The Council on Environmental Quality issued an interpretive memorandum on Jun 24, 

2005, regarding analysis of past actions which states, “agencies can conduct an adequate cumulative 

effects analysis by focusing on the current aggregate effects of past actions without delving into the 

historical details of individual past actions.” For these reasons, the analysis of past actions in this section 

is based on the existing conditions.

This analysis evaluated the effect of future projects for their cumulative effects. The spatial extent of 

effects on the soil is limited to those areas that have a direct or indirect effect to the soil. The activities 

expected to cumulatively effect the soils are limited to those activities associated with the Hazard Tree 

project that is proposed for Level 3-5 roads. 
Rim Recovery Soil Report

24

For a complete list of the past, present, and future projects planned for the Rim Fire area, refer to the 

project record.

Alternative 1 (Proposed Action)

Direct and Indirect Effects

Indicator 1: Soil Stability and Effective Soil Cover

The effects of soil stability and effective soil cover are directly related and analyzed together. Erosional 

processes, which are the direct measures of soil stability, are primarily changed by management activities 

when those activities affect soil cover and porosity. While it is not feasible to predict the soil cover 

following treatments for every location, general assumptions can be made in regards to the departure of 

soil cover from pre-existing levels based on proposed activities. Activities expected to affect soil stability 

and cover include harvest activities and fuels treatments.

The existing condition of soil stability and soil cover are above threshold values. The proposed activities 

of Alternative 1 will do little to change this indicator. There will be slight increases in soil cover due to 

activity fuels, but not enough of an increase in cover values (less than 50 percent) is expected where the 

Rim Fire resulted in deficiencies due to high vegetation severity. Erosion rates and Erosion Hazard 

Ratings will also remain little changed.

Shakesby et al. (1996) found that logging residue can decrease erosion and retain sediment in postfire 

logged sites. In general, harvest activities are expected to generate ground cover from both slash and 

breakage. However, there is conflicting research, indicating some areas may not have sufficient soil cover 

post treatment. Studies directly measuring the change in soil cover following salvage activities are 

limited; studies of fuel increases however can serve as a reasonable proxy. McIver and Ottmar (2007) 

found that post-fire logging in an Oregon Ponderosa pine forest increased the amount of material less than 

3 inches diameter to 2.8 tons/acre compared to 0.6 tons/acre in burned but unsalvaged stands. Donato et 

al. (2006) found that fine woody material increased above pre-fire levels following salvage logging of the 

2002 Biscuit Fire. Although these studies reported material in weight as opposed to percentage ground 

cover, they support the idea that logging activities generate fine material that translates into soil cover. 

However, Chase (2006) found that both tractor logging and cable logging increased the amount of bare 

soil compared to burned and unlogged control plots. The amount of bare soil decreased with helicopter 

logging. Chapter 3.05 (Fire and Fuels) also discusses the material expected to be left after salvage 

operations.

Fuel treatments are also expected to affect the amount of soil cover. Machine-piling with a rake- fitted 

dozer followed by burning is expected to reduce soil cover to less than 20 tons per acre, creating areas 

where soil cover may go below threshold values. Machine-piling is not intended to reduce the fine fuels in 

contact with the ground, but because of “sweeping” of the surface by the larger targeted material, some 

surface cover will likely be displaced to piles. Monitoring by project administrators is expected to keep 
Rim Recovery Soil Report

25

this displacement to a minimum. Pile-burning will have an impact on soil cover at the location of the pile. 

Fuel staff target 80 percent consumption of material in a pile, which will likely leave less than 50 percent

ground cover in that location. Burn piles will be dispersed throughout a unit and typically burn in a 

mosaic. The area extent of the piles is unknown; however it is expected that pile burning along with other 

soil disturbing activities will occupy less than 15 percent of a unit to conform to Forest Plan Standard and 

Guidelines.

A WEPP analysis was used to predict hillslope erosion. Skid trails and cable corridors are compacted 

surfaces with reduced ground cover that concentrate water and increase rill and gully erosion at water 

outlets or along the compacted surfaces. Proper installation of BMPs on skid trails will help minimize the 

increased sediment production due to salvage logging (Chase 2006). Decompacting of primary and 

secondary skid trails to increase infiltration and surface roughness along with implementation of BMPs is 

expected to minimize the erosion and sedimentation related to the concentration of hillslope water flow 

caused by skidding.

Soil cover and erosion were evaluated both at the area extent of the proposed salvage treatments and on a 

per unit basis. About 59 percent of the proposed action area currently has soil cover of less than 50

percent and 304 units are currently identified as likely to have less than 50 percent cover in more than 15

percent of the area. It is not expected that these values will change significantly as a result of proposed 

activities. Although effective soil cover is expected to increase in areas of high vegetation burn severity, it 

is unlikely that activity fuels will add enough soil cover to increase values above the 50 percent threshold 

in these areas. In the low and moderate vegetation burn severity, harvest and fuels activity are not likely to 

drop soil cover values below the 50 percent threshold since only activity generated material is treated 

during timber sale implementation

Table 6 shows modeling of the proposed activities which result in erosion rates dropping slightly for the 

project area from 3.1 tons per acre to 3.0 tons per acre, while the number of units where erosion rates 

exceeded acceptable soil loss increased slightly from 178 to 181. This increase is likely due to the 

decrease in cover values on steep slopes that are proposed for helicopter or skyline logging. EHR rates 

also will change little as a result of proposed activities. The number of units where the EHR exceeds 

‘Moderate’in over 15 percent of the unit stayed unchanged at 188 units. The small differences in erosion 

rates and the lack of change in EHR ratings are considered insignificant, but it is likely that erosion will

increase as a result of the proposed action.

The use and development of temporary roads is part of the connected action to timber harvest that is 

expected to affect both soil cover and soil stability. The temporary roads were not considered in the unitby-unit analysis and are addressed separately. About 4 miles of temporary roads will be constructed and 

18 miles of existing temporary roads will be used. Ten of those 18 miles of existing temporary roads will
Rim Recovery Soil Report

26

be obliterated. It is expected that temporary roads will be deficient in ground cover, however, subsoiling, 

recontouring, installation of waterbars, and application of ground cover will reduce the risk of erosion.

In summary, there is much uncertainty regarding the effects proposed activities will have on soil cover 

and erosion. Research on post-fire logging resulting in erosion is limited (McIver and Starr, 2001) and is 

not consistent. The lack of change from current conditions based on proposed activities did not show a 

substantial decrease or increase in EHR or erosion in the models used for this analysis. Although erosion 

may increase as a result of salvage activities, the magnitude, as Chou (1994) suggests is likely 

overwhelmed by the erosion and sedimentation resulting from the fire itself. What is clear from both 

research and modeling is that most of the analysis area will remain below minimum threshold values for

effective soil cover and will continue to exceed soil stability thresholds. 

Skid trails and cable rows provide a conduit for rill erosion formation thereby increasing the amount of 

erosion and sediment (Chase 2006). Management requirements are incorporated into the proposed action 

to mitigate the effects of logging effects on erosion and soil cover. Also, most temporary roads will be 

obliterated (only those currently operating under other special uses will remain). Madej (2001) found that 

the activities proposed for restoration of skid trails, landings and temporary roads reduced sediment and 

runoff significantly when applied to closing forest roads. 

Indicator 2: Surface Organic Matter

Proposed activities expected to affect surface organic matter include hauling, temporary road construction 

and prescribed burning. Harvest activities including the use of tracked feller-buncher type equipment will 

affect the surface organic matter with localized surface displacement, but will not have a detrimental soil 

effect on the stands where those activities occur. Long-term surface organic matter is more likely to occur 

as a result of skidding material to landings and cable yarding material along cable corridors. Removal of 

the material will be highest closer to landings and on portions of the cable corridors that do not support a 

fully suspended load. Fresh deposits of broken branches and needle cast will occur, but this accumulation 

is expected to be thin with surface coverage below threshold standards.

Long-term recovery of the soil organic material in high soil burn severity areas may be affected by the 

removal of the overstory. With the fine organic material and needles consumed in high severity vegetation

burn areas, surface organic matter recovery depends on snag recruitment and needle fall to the soil 

surface. During field surveys, those portions of the analysis area with the highest depletion of surface 

organic material correlate with thick stands of burned trees smaller than the 16 inch diameter at breast 

height that will not be removed. Therefore, material is likely to remain to decompose and rebuild soil 

organic layers over time. 

Piling of fuels is not expected to significantly affect surface soil organic matter; however, piling will

reduce the amount of material that could contribute to future surface organic matter. Tractor-piling with a 

rake is likely to cause limited disturbance and displacement of the organic soil layers as target material 
Rim Recovery Soil Report

27

sweeps the soil surface. The burning of piles is expected to generate enough heat to consume all soil 

organic layers although the extent is expected to be much lower than the threshold of disturbance of 15

percent extent.

Indicator 3: Soil Organic Matter

Displacement is the removal of surface layers of the mineral soil generally by mechanical means. All 

salvage activities have the potential to substantially displace the SOM. Feller-buncher activity will cause 

limited displacement. Displacement from harvesters is generally not considered detrimental displacement 

because the effects are localized. In ground based mechanical harvest units higher levels of displacement 

are likely to occur with skidding operations. Skidder tracks along with dragging of trees digs into the 

mineral soil surface and wedges the surface to the side. This creates berms and piles along the edges of 

skid trails. Skyline units are expected to have displacement along portions of the corridors, with higher 

displacement levels occurring closer to the landings. The most severe displacement is expected to occur 

on steeper temporary roads and skid trails. The steeper the slope on both temporary roads and skid trails, 

the more severe the displacement is likely to be due to cut-banking. Displacement results in the removal 

of nutrient rich loamy material exposing the high clay content subsurface. This subsurface is deficient in 

soil nutrients, reduces infiltration, and has higher natural soil strength impeding root penetration. Fox et 

al. (1989) found displacement caused by windrowing decreased forest productivity dramatically.

Displacement can also lead to channelized flow from entrainment between berms, reduced infiltration,

reduced surface roughness, and in the case of roads, high levels of compaction. While local displacement 

damages soil function, the activities resulting in negative effects will not exceed 15 percent of the area 

and impacts are not expected to be significant.

The other mechanism of displacement involves heat penetration into the mineral soil sufficient enough to 

char or volatize the organic compounds that form SOM. The diminishment of SOM caused by the Rim 

Fire dominates the existing condition condition with 72 units exceeding threshold values whereas no units 

exceed threshold values with mechanical disturbance; however, pile and jackpot burning is expected to 

produce enough heat where fuel loads exceed 20 tons/acre to consume SOM within the footprint of the 

piles. The extent and burn severity is unknown and is dependent on the size of the piles and distribution of 

fuels. The impact will be limited to the pile locations and small areas of high concentrations and therefore 

is not expected to be significant.

The development of skid trails will have the largest impact on SOM, but management requirements will

mitigate the effects; particularly reuse of existing mechanical disturbances where practical. It is clear from 

LiDAR analysis, there are units with little to no displacement 72 units where the existing condition 

exceeds the 15 percent threshold for disturbance. Existing skid trails will be reused where practical. For 

many of the tractor units, existing skid trails are expected to be adequate for salvage harvest and new skid 

trail development will be unnecessary or minimal. Displacement caused by new skid trails and temporary 
Rim Recovery Soil Report

28

road construction will be considered a long-term disturbance as no mitigations to replace displaced SOM 

are planned.

SOM will recover regardless of management activities in the long-term. SOM is expected to recover more 

rapidly in areas where SOM was displaced by fire, because nutrient cycling of ash and rapid vegetation 

regrowth of root dense, nitrogen-fixing shrubs will facilitate deposition of organic matter by decomposing 

roots and mineralization of decaying material in the soil. On soils where SOM will be impacted by 

mechanical activities, the recovery is expected to be slower because residual nutrients of the fire will be 

displaced and SOM replenishing vegetation will be stunted where compaction occurs. 

Indicator 4: Soil Porosity

Changes in porosity occur both by the reduction of soil pore space by force applied to the soil surface 

(compaction) and the filling of pores by soil and ash material (soil sealing). Heavy equipment use is 

expected to increase compaction within treated areas. For this project, the dominant soil is rated as high 

compaction hazard primarily because of the increasing clay at depth. Within tractor units, compaction is 

expected to increase depending on the number of passes and the weight of the machine. Feller-buncher 

harvesting equipment is considered low ground-pressure equipment and typically does not travel the same 

location more than twice. Compaction is therefore expected to be slight where mechanical harvesting 

occurs. 

Skidding operations, however, will detrimentally compact the soil. Williamson and Neilson (2000) found 

that most maximum compaction occurs after 3 passes of log-laden equipment. Landings are areas of high 

compaction because they support skidding equipment, processors, and log trucks but all landings will be 

deep tilled after use on this project. Management requirements confine the extent of detrimental 

disturbance from skid trail patterns to less than 15 percent of a unit. Through LiDAR analysis supported 

by field verification, it was determined that past activity has resulted in only 3 units exceeding threshold 

values based on reduced porosity. However, it is likely that more units will exceed 15 percent disturbance 

because the lack of ground cover will make the soil more susceptible to compaction. Management 

requirements, such as subsoiling, substantially decrease the negative effects of compaction. Powers 

(2002) observed that subsoiling significantly improved the porosity of soils. Subsoiling temporary roads, 

landings and skid trails will limit the extent and duration of effects in these areas. Detrimental disturbance 

is expected to be minimal in helicopter units. The risk of compaction will be increased in those sky line 

and helicopter units where feller-buncher type harvesters assist handfallers in removing trees. In these 

units where no skid trails will be used, detrimental compaction is not expected outside cable corridors.

Although the effects of soil sealing resulting from the fire may be reduced before implementation starts, it 

is likely that soil surface disturbance through mechanical harvest activities will further reduce the effects 

of soil sealing by exposing more developed soil structure. Compacted road surfaces reduce infiltration to 

near zero. Forest roads are the largest source of erosion. This is exacerbated in a burned environment 
Rim Recovery Soil Report

29

because the capacity of the landscape to moderate flow and trap sediment is greatly reduced (Peterson et 

al. 2009). The extent of new and temporary road construction is limited, and while compaction of these 

surfaces is severe, the limited extent of activities is not expected to result in significant impacts to forest 

productivity. 

Cumulative Effects

The Rim Fire resulted in significant impacts to soils within the analysis area including increases in 

erosion potential, loss of soil cover, loss of soil organic matter and reduction in soil porosity from soil 

sealing. With no other actions planned (Appendix B) within the Rim Recovery soil analysis area, the 

cumulative effects for Alternative 1 are the same as the direct and indirect effects of Alternative 1. The 

cumulative effect of Alternative 1 is expected to slightly improve soil cover from activity fuels and will

increase the porosity in existing skid trails, landings, and abandoned roads identified for use as temporary 

roads in the project; however in general the activities are not expected to substantially improve the soil 

indicators within the analysis area.

Alternative 2 (No Action)

Direct and Indirect Effects

Indicator 1: Soil Stability and Effective Soil Cover

Under Alternative 2, only indirect effects to soils occur. Soil cover for erosion protection will be limited 

to natural rates of accumulation. In areas of lower burn severity, needlecast from dead tree canopies will

continue to accumulate as ground cover at natural rates. Soil stability will remain reduced and erosion risk 

will remain elevated in the short term, for 1 to 3 years, until ground cover and vegetation are 

reestablished. Higher burn severity areas currently lacking effective soil cover will recover more slowly 

because woody material will be deposited naturally at a slower rate. Where the potential for soil cover to 

be added through needlecast is low, soil cover in the short term will mainly be added as dead trees shed 

branches and fall. Effective soil cover will only be fully reestablished after surface vegetation recovers. 

This will expose the soil to higher erosion potential over the next 3 to 5 years. Under this alternative, 

WSAs will not receive additional ground cover as proposed in Alternatives 3 and 4 and therefore the 

analysis area will not realize a reduction in erosion and sediment in areas identified as higher risk for 

sedimentation and erosion. Areas will have continued accelerated erosion for 3 to 5 years until soils

stabilize and vegetation cover returns. 

Indicator 2: Surface Organic Matter

The Fuels Report (project record) states that smaller diameter class snags will fall within the fire 

perimeter at the highest rate in the first ten years. Larger snags will persist for relatively longer time 

periods, but most snags will be expected to fall within 20 years post-fire (Hood, Chuck and Smith 2007). 

Within 10 years, surface fuels are projected to be 78 tons per acre. Within 30 years, surface fuels are 

projected to average 98 tons per acre due to dead trees falling over (Fuels Report). Richie (2013) showed 

that 10 years after the Black Mountain Fire, 80 percent of the basal area was on the ground. These 
Rim Recovery Soil Report

30

predicted fuel loading levels pose a risk to soil productivity if reburned in a subsequent wildfire. The fuel 

loadings predicted exceed the levels that cause severe soil heating in a fire (Brown et al. 2003). While it is 

not possible to accurately predict when a fire will reburn, predicted fuel loadings in Alternative 2 will 

create an elevated fire hazard leading to excessive soil heating damage. One study, in adjacent Yosemite 

National Park, examined the effects of multiple fires on vegetation in unlogged areas. Areas of high 

severity were more likely to burn with an increased area of high severity again in future fires, partly 

because of a post-fire vegetation shift from forest to brush or chaparral (Wagtendonk 2012). Areas that 

burned at low or moderate burn severity initially and maintained forest conditions were more likely to 

burn at low or moderate burn severity in later fires. 

Other studies show that if salvaged logged areas reburn, they may have higher overall vegetation burn 

severity and fire effects than areas that were unlogged (Fraver et al. 2011; Thompson 2007). Most studies 

on this topic analyze the vegetation effects of reburn. There are fewer studies that directly compare soil 

effects and associated fire risk or hazard in unlogged and salvage logged areas, therefore impacts to soils 

in this scenario are less clear. It is expected that fuel loading in contact with the soil surface is likely to be 

the most important variable in determining risk of fire damage to the soil during a reburn and this 

Alternative will provide far more down woody material than treated stands. 

Indicator 3: Soil Organic Matter

Without the proposed management requirements associated with soil ground cover in WSAs and other 

areas with elevated erosion rates, soil organic matter could be lost through surface erosion until soils 

stabilize. In lower burn severity areas, less soil organic matter will be lost due to erosion without 

alteration by active management, and in the long-term it will develop at natural rates. With increased fuel 

loadings described under indicator 2, it is possible that soil heating effects could increase in future fires. 

High surface temperatures, especially from burning downed logs, raise soil temperatures, resulting in 

increased volatilization of soil organic matter. Prolonged heating under burning logs will lead to lethal 

temperatures of greater than 122 degrees Fahrenheit for fungi and 212 degrees Fahrenheit (Boyer and 

Dell, 1980) for nitrifying bacteria at greater soil depths. The loss of SOM is probably the most serious 

concern in terms of long-term soil effects. SOM dynamics and nutrient cycling will continue to recover 

naturally, once vegetation becomes re-established.

Indicator 4: Soil Porosity 

Existing levels of compaction will not be improved or changed. Existing compaction on abandoned roads 

and skid trails will remain until natural processes restore soil porosity. Additional compaction will not 

occur; however, areas with compacted, benched-in skid trails will not be subsoiled and are likely to 

remain compacted for decades.
Rim Recovery Soil Report

31

Cumulative Effects

With no other actions planned (Appendix B) within the Rim Recovery soil analysis area, the cumulative 

effects for Alternative 2 are the same as the indirect effects of Alternative 2. The cumulative effect of 

Alternative 2 is not expected to improve soil cover or soil porosity.

Alternative 3 

While Alternative 3 includes less commercial salvage acres, the area of impact is increased through 

proposed biomass removal. Impacts of biomass removal will result in similar soil effects, as machinery 

used to accomplish the activities are the same. The proposed temporary road use increases by 14 miles 

with an increase of approximately 6 miles of new temporary roads. New road construction, however,

drops from 5.4 miles to 1 mile. The most substantial change, affecting the soil resource, is that Alternative 

3 provides additional soil cover on 3,536 acres using watershed treatments if post-activity soil cover is not 

greater than 50 percent in WSAs.

Direct and Indirect Effects

Indicator 1: Soil Stability and Effective Soil Cover

The effects of activities to soil stability and effective soil cover from salvage activities and road work 

activities would be similar to Alternative 1. The addition of soil cover in the WSAs improves the soil 

stability and the amount of effective soil cover substantially due to the targeted application of soil cover in 

areas identified as most erodible and lacking in soil cover. Table 6 displays the modeled erosion rate 

decreases from the existing 3.1 tons per acre per year down to 2.2 tons per acre per year for Alternative 3. 

The number of units where the average unit erosion rates exceeded T-Factor similarly will decrease when 

compared to the existing condition from 194 to 136 units. 

Improvement in effective soil cover is also expected to increase, but will not be as considerable as the 

erosion rate reduction. This is due to cover being added only in the highest potential erosion rate areas. 

Areas deficient in soil cover on gentle slopes are expected to remain deficient in soil cover until it 

recovers naturally over time. The area of Alternative 3 that is expected to have less than 50 percent soil 

cover will decrease as a result of proposed activities from nearly 60 percent to 53 percent. The number of 

units where the amount of soil cover is less than 50 percent in at least 15 percent of the unit is expected to 

decrease from 335 to 329 units.

The amount of area and number of units that are a ‘Moderate’ EHR rating or less improved with the 

modeled additions of soil cover, but not as dramatically as improvements in modeled erosion rates using

WEPP. The area of EHR ratings above ‘Moderate’ decreased by 1 percent from 22 percent to 21 percent

and the number of units that have more than 15 percent of the unit area with a rating of ‘High’ or ‘Very 

High’ decreased from 209 units to 203 units. Where EHR rating is improved from ‘Very High’ to ‘High’ it 

is still considered above thresholds set by management direction. Although assumptions are factored into 

all modeling, the improvement of erosion rates, EHR, and soil cover is substantial enough to conclude the 
Rim Recovery Soil Report

32

proposed activities in Alternative 3 will decrease erosion and increase cover sufficiently that they will

have a net benefit to the analysis area.

Indicator 2: Surface Organic Matter

The effects to surface fine organic matter will be the same as Alternative 1. The material added to the 

surface as a result of WSA treatments will not add to the surface organic matter. This material is 

undecomposed coarser material derived from non-commercial stems and will only cover 50 percent of the 

soil. Treatments will not add appreciably to soil productivity.

Indicator 3: Soil Organic Matter

Same as Alternative 1. 

Indicator 4: Soil Porosity

The effects to soil porosity will be similar to what is described for Alternative 1. The additional treatment 

will increase the amount of compaction within the analysis area. Additional areas of soil disturbance will

not be expected to increase the percent of compaction in any treated areas above the amount expected 

with Alternative 1. Soil disturbance within Alternative 3 will be reduced in areas where treatment 

proposed in Alternative 1 does not occur. However, existing compaction on skid trails and landings within 

untreated areas will also persist.

Cumulative Effects

Same as Alternative 1, except the addition of organic cover for watershed treatments would improve soil 

cover and reduce erosion rates as described in the direct and indirect effects of Alternative 3.

Alternative 4 

Direct and Indirect Effects

Indicator 1: Soil Stability and Effective Soil Cover

Table 6 shows the modeled erosion rate for Alternative 4 is similar to Alternative 3 with a decrease from 

3.0 tons per acre per year down to 2.2 tons per acre per year. On a unit-by-unit basis, the number of units

where the average unit erosion rates exceeded T-Factor similarly decreased over the existing condition 

from 186 units to 131 units. The area of Alternative 4 that has less than 50 percent soil cover decreases 

from nearly 59 percent to 52 percent. The number of units where the amount of soil cover is less than 50

percent in at least 15 percent of the unit decreases from 317 to 311 units. The amount of area and number 

of units at a ‘Moderate’ EHR rating or less increased, but improvements from added soil cover for EHR 

were not as dramatic as for modeled erosion rates with WEPP. The area of EHR ratings above ‘Moderate’ 

decreased by 2 percent from 22 percent to 20 percent and the number of units that are expected to have 

more than 15 percent of the unit area with a rating of ‘High’ or ‘Very High’ improved from 197 units to 

191 units which is the same change in the number of units as Alternative 3. 

Indicator 2: Surface Organic Matter
Rim Recovery Soil Report

33

Same as Alternative 3. 

Indicator 3: Soil Organic Matter

Same as Alternative 3. 

Indicator 4: Soil Porosity 

The effects to soil porosity will be similar to that described for Alternative 3. Soil disturbance within 

Alternative 4 will be reduced in areas where treatment is proposed in Alternative 3 does not occur. 

However, existing compaction on skid trails and landings within untreated areas will persist.

Cumulative Effects

Same as Alternative 1, except the addition of organic cover for watershed treatments would improve soil 

cover and reduce erosion rates as described in the direct and indirect effects of Alternative 4.

Summary of Effects Analysis across All Alternatives

Table 6 provides a summary of the effects across all alternatives for Indicators 1 and 2. Indicators 3 and 4 

are dependent on analysis of LiDAR by the Remote Sensing Lab and not yet complete. For Indicators 3 

and 4, the effects of each alternative are compared qualitatively. Indicators for erosion, soil cover, fine 

organic material, and soil organic material exceed threshold values used in the analysis. 

Indicator 1: Soil Stability and Effective Soil Cover

Alternatives 1 and 2 are similar in the effects to soil stability. High erosion rates and low cover values will

remain for both alternatives; however, slight improvements to average erosion rates occur in Alternative 1 

due to the addition of activity fuels. Conversely, the number of units where the erosion rates exceed 

acceptable soil loss increases in Alternative 1 due to the decrease in soil cover in areas that have near 100

percent soil cover in the existing condition. Because of the addition of 50 percent cover prescribed in the 

WSA units, Alternatives 3 and 4 show marked improvement in cover values, EHR and erosion rates. The 

treatments are prescribed in those areas where deficiencies in soil stability pose the greatest risk to 

watershed resources.

Indicator 2: Surface Organic Matter

Little change is expected in Surface Organic Matter between the four alternatives.

Indicator 3: Soil Organic Matter

Little change is expected in Soil Organic Matter between the four alternatives.

Indicator 4: Soil Porosity

The overall porosity for Alternatives 1, 3, and 4 is expected to improve due to implementing the 

management requirement to subsoil primary skid trails and temporary road prisms situated on existing 

disturbance. The soil supporting most of the existing skid trails within the proposed units have reduced 

porosity exceeding threshold values. Porosity decreases in areas off of skid trails may also occur, but the 
Rim Recovery Soil Report

34

effect is expected to be limited. Also, mechanical treatment in the action alternatives may increase the 

porosity by decreasing the effects of soil sealing. Porosity does not change under Alternative 2.

Table 6 Summary of Indicators by Alternative

Indicators Alternative 1

(357 units + HT)

Alternative 2

(No Action)

Alternative 3

(368 units + HT)

Alternative 4

(350units + HT)

# Indicator Metric Existing Post Existing Post Existing Post Existing Post

1 Soil Stability, 

Erosion

Average Erosion Rate (tons/acre) 3.1 3.0 3.1 3.1 3.1 2.2 3.0 2.2

Number of units exceeding acceptable soil 

loss 178 181 194 136 186 131

1 Soil Stability, 

Erosion Hazard 

Rating

Number of units with EHR greater than 

Moderate rating in greater than 50 percent 

of unit

188 188 209 203 197 191

Percent area greater than Moderate Rating 23 23 23 23 22 20 22 20

1 Soil Cover Number of units with more than 50 percent 

of unit having less than 50 percent soil 

cover

304 304 335 329 317 311

Percent area with less than 50 percent cover 58.9 58.9 60.0 60.0 59.5 52.8 58.7 51.5

2 Surface Organic 

Material

Percent area with less than 50 percent cover 

of surface organic material 61 61 61 61 61 61 61 61

3 Soil Organic 

Matter1

Number of units with more than 15% of the 

area with below threshold disturbance 72 - 97 - 90 -

4 Soil Porosity1 3 - 4 - 4 -

HT=Hazard Tree Removal (Roadsides)

1. The post activity values for indicators 3 and 4 are unknown due to the uncertainty of the extent existing disturbance will be used.

References

Chase, H.C. 2006. “Effects of a Wildfire and Salvage Logging on Site Conditions and Hillslope Sediment 

Production: Placer County”. Thesis

Boyer, D.E., and J.D. Dell. 1980. “Fire effects on Pacific Northwest Soils”. U.S. Forest Service Report R6 

WM 040. Pacific NW Forest Range Experiment Station, Portland, OR.

Brown, J.K., E.D. Reinhardt, and K.A. Kramer. 2003. “Course woody debris: Managing benefits and fire 

hazards in recovering forest, General Technical Report, RMRS-GTR-105”. USDA Forest Service, 

Donato, D.C.; Fontaine, J.B.; Campbell, J.L.; Robinson, W.D.; Kauffman, J.B.; Law, B.E. 2006. “Postwildfire logging hinders regeneration and increases fire risk”. Science. 311: 352.

Elliot, William J.; Hall, David E. 2010. Disturbed WEPP Model 2.0. Ver. 2013.07.01. Moscow, ID: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research Station. Online at 

<http://forest.moscowfsl.wsu.edu/fswepp>.
Rim Recovery Soil Report

35

Hood, Sharon M., Sheri L. Smith, and Daniel R. Cluck. 2007. "Delayed conifer tree mortality following 

fire in California." General Technical Report PSW-GTR-203, USDA Forest Service, Pacific Southwest 

Research Station, Albany, Calif, USA (2007).

Fox, T.R., Morris, L.A., Maimone, R.A., 1989. “The impact of windrowing on the productivity of a 

rotation age loblolly pine plantation”. In: Proceedings of the Fifth Biennial Southern Silviculture 

Research Conference, New Orleans, LA. USDA Forest Service General Technical Report No. SO-74, pp. 

133-140.

Fraver, S. T. Jain, J.B. Bradford, A.W. D’Amato, D. Kastendick, B. Palik, D. Shinneman, and J. 

Stanovick. 2011. “The Efficacy of salvage logging in reducing subsequent fire severity in coniferdominated forests of Minnesota, USA”. Ecological Applications, 21(6). 1895-1901.

Knapp, E. E., Weatherspoon, C. P., & Skinner, C. N. (2012). “Shrub seed banks in mixed conifer forests 

of northern California and the role of fire in regulating abundance”. Fire Ecology 8 (1): 32-48. doi: 10: 

4996/fireecology.

Larsen, I.J, MacDonald, L.H., Brown, E., Rough, D., and Welsh, M.J. 2009. “Causes of Post-Fire Runoff 

and Erosion: Water Repellency, Cover, or Soil Sealing?” Soil Sci. Soc. Am. J. 73:1393-1407

Madej M.A. 20012. “Erosion and sediment delivery following removal of forest roads” Earth Surf. 

Process. Landforms 26, 175-190.

McIver, J.; Ottmar, R. 2007. “Fuel mass and stand structure after postfire logging of a severely burned 

ponderosa pine forest in northeastern Oregon”. Forest Ecology and Management. 238: 268-279.

McIver J.D., Starr L. 2001. “A Literature Review on the Environmental Effecs of Postfire Logging” West. 

J. Appl. For. 16(4): 159-168.

Neary et al. 1999. "Fire effects on belowground sustainability: a review and synthesis." Forest Ecology 

and Management,: 51-71.

Neary, Daniel G.; Ryan, Kevin C.; DeBano, Leonard F., eds. 2005. (revised 2008). Wildland fire in 

ecosystems: effects of fire on soils and water. Gen. Tech. Rep. RMRS GTR-42-vol.4.

Pannkuk, C. D., and P. R. Robichaud, 2003. “Effectiveness of needle cast at reducing erosion after forest 

fires”, Water Resour. Res., 39(12), 1333,
Rim Recovery Soil Report

36

Parsons, A, PR Robichaud, SA Lewis, C Napper, JT Clark, 2010. Field Guide for Mapping Post-Fire Soil 

Burn Severity. USFS Rocky Mountain Research Station, General Technical Report RMRS-GTR-243.

Peterson, D. L., Agee, J. K., Aplet, G. H., Dykstra, D. P., Graham, R. T., Lehmkuhl, J. F., ... & Stuart, J. D. 

(2009). “Effects of timber harvest following wildfire in western North America”. USDA Forest Service. 

Pacific Northwest Research Station, General Technical Report PNW-GTR-776.(Portland, OR).

Poff, R. 1996. "Effects of Silvicultural Pratices and Wildfire on Productivity of Forest Soils." Status of the 

Sierra Nevada,: Vol. II (16): 477-493.

Powers et al. 1998. "Assessing soil quality: Practicable standards for sustainable forest productivity in the 

US." SSSA,: 53-80.

Powers, R.F. 2002. Effects of Soil Disturbance on the Fundamental, Sustainable Productivity of Managed 

Forests. USDA Forest Service General Technical Report. PSW-GTR-183. p.63-81

Powers, R.F.; Scott, D.A.; Sanchez, F.G.,; Voldseth, R.A.; Page-Dumroese, D.; Elioff, J.D.; Stone, D.M. 

2005. “The North American long-term soil productivity experiment: findings from the first decade of 

research.” Forest Ecology and Management. 220:31-50/ UT: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Research Station. 250 p.

Powers et al. 2005. "Long Term Soil Productivity." Forest Ecology and Management: 31-50.

Parsons, A, PR Robichaud, SA Lewis, C Napper, JT Clark, 2010. “Field Guide for Mapping Post-Fire Soil 

Burn Severity”. USFS Rocky Mountain Research Station, General Technical Report RMRS-GTR-243.

Ritchie, M.W.; Knapp, C.N.; Skinner, C.N. 2013. “Snag longevity and surface fuel accumulation 

following post-fire logging in a ponderosa pine dominated forest”. Forest Ecology and Management. 287: 

113–122.

Robichaud, P.R., W.J. Elliot, L. MacDonald, R. Coats, J.W. Wagenbrenner, S.A. Lewis, L.E. Ashmun, and 

R.E. Brown. 2011. “Evaluating Post-fire Salvage Logging Effects on Erosion”. Final Report Joint Fire 

Science Program 06-3-4-21. 21p

Rust, Brad, D. Young, C. Kvamme, M. Flores, and K. Takenaka. 2013. “BAER Assessment Soils Report 

– Rim Fire”. USDA, Technical. Sonora, California.

Thompson, J.R., T.A. Spies, L.M. Ganio. 2007. “Reburn severity in managed and unmanaged vegetation 

in a large wildfire”. PNAS, 104 (25). 10743-10748.
Rim Recovery Soil Report

37

USDA. 1988.Cumulative Off-site Effects Analysis, Interim Directive No. 1. Soil and Water Conservation 

Handbook. FSH.2509.22, chapter 20. San Francisco: USDA Forest Service, 

USDA. 1990. Soil EHR, R5 Amendment No. 2. Soil and Water Conservation Handbook. FSH 2509.22, 

Ch. 50. R5 Handbook Amendment, San Francisco: USDA Forest Service.

USDA. 1999. Pacific Southwest Region Soil Interpretations. Technical, Vallejo: USDA Forest Service

.

USDA. 2000. Water Quality Management for Forest System Lands in California: Best Management 

Practices. Technical, Vallejo: USDA Forest Service.

USDA. 2004. Sierra Nevada Forest Plan Amendment Record of Decision. USDA Forest Service, Pacific 

Southwest Region, Vallejo, CA.

USDA. 2008. Soil Survey Geographic (SSURGO) database for Stanislaus National Forest Area. USDA 

National Resources Conservation Services (NRCS)

USDA. 2010a. Stanislaus Land and Resources Plan. 

USDA. 2010b. Forest Service Manual 2500, Chapter 2550--Soil Management. Manual, Washington, DC.: 

USDA Forest Service.

USDA. 2012a. Region 5 Soil Management Handbook Amendment – 2550 FSM Amendment, Vallejo: 

USDA Forest Service.

USDA. 2012b. National Best Management Practices for Water Quality Management on National Forest 

System Lands. Vol I. Technical, USDA Forest Service.

Wagtendonk, J.W.V., K.A.V Wagtendonk, and A.E. Thode. 2012. “Factors associated with the severity of 

Intersecting Fires in Yosemite” National Park, California, USA. Fire Ecology 8(1). 11-32.

Williamson, J.R. and W.A. Neilson. 2000. “The influence of forest site on rate and extent of soil 

compaction and profile disturbance of skid trails during ground-based harvesting”. Can. J. of For. Res. 

30: 1196-1205.
Rim Recovery Soil Report

38

Appendices

A. Generalized Soil Map

B. Soil Burn Severity Map of the Rim Fire Area

C. Vegetation Severity Map of the Rim Fire Area.

D. Methodology

E. Erosion Hazard Rating: Units that exceed Moderate rating in greater than 

15% of any unit.
Rim Recovery Soil Report 

39

APPENDIX A: Generalized Soil Map of the Stanislaus Portion 

of the Rim Fire.

fam tode Family 

A - Dystric Lithic Xerochrepts 

8 Dystric Xerochrepts 

c Dystric Xerorthents 

D Entic Cyrumbrepts 

E Fiddletown 

F Gerle 

G Half Dome 

H Holland 

Humic Dystroxerepts 

Josephine 

K Lithic Xerumbrepts 

L McCarthy 

M Pinole 

N Rock Outcrop 

0 Typic Dystroxerepts 

p Ultic Haploxeralfs 

Q V\lintoner 

R Xerolls 
Rim Recovery Soil Report

40

Appendix B: Soil Burn Severity of the Rim Fire Area 

Rim Soil Burn Severity 

Unburned 

- Low 

Moderate 

- High 
Rim Recovery Soil Report

41

Appendix C: Vegetation Severity of the Rim Fire Area
Rim Recovery Soil Report

42

Fire Severity 

- Unburned 

- Low Severity 

Moderate Severity 

- High Severity 
Rim Recovery Soil Report

43

Appendix D: Methodology

SOIL DESCRIPTION AND INTERPRETATION

Soils information for this analysis was derived from the Stanislaus National Forest Soil Survey and 

obtained from the Natural Resources Conservation Services (NRCS) Web Soil Survey (WSS). The WSS 

provided both spatial and soil property information used for both field survey and analysis. Specific 

interpretations and soil data properties were derived from the NRCS Soil Data Viewer (SDV) which is a 

GIS extension that helps the user analyze soils in a digital environment. Properties derived from the SDV 

include soil texture, depth, rock fragments, soil taxonomy, soil composition within a unit, and acceptable 

soil loss. 

There were 66 soil map units within the fire area. Because of the size of the fire, a soil map was 

generated based on dominant soil series in a map unit. A soil map unit is a collection of areas defined 

and named the same in terms of their soil components (e.g., series) or miscellaneous areas or both. Soil 

series are families of soils having similar profiles, and developing from similar original materials under 

the influence of similar climate and vegetation. The soil map is included in Appendix A of this report

SOIL EROSION HAZARD RATING

The Region 5 Soil Erosion Hazard Rating (EHR) System (USDA 1990) was used to rate the risk of soil 

erosion for all soils in the project area post fire, post implementation and incorporating watershed 

treatments. This system uses various physical soil properties along with climate and site-specific 

conditions to rate soils for hazard of sheet and rill erosion. The following parameters used in the 

evaluation of EHR are as follows.

• Soil Texture: Derived from SDV based on soil map unit

• Slope Steepness: A 10meter digital elevation model was used to derive the slope ranges 

used to evaluate EHR. Those ranges are 0-15%, 16-30%, 31-45%, and 46+% slopes.

• Aggregate Stability Adjustment: The only adjustment necessary for aggregate stability is 

for the alteration of soil structure caused by high soil burn severity. 

• Climate: The 2-year, 6-hour value derived from the Precipitation Frequency Atlas of the 

Western States Atlas, Volume 2.

• Infiltration and permeability: Infiltration is based on soil depth and soil texture which 

were derived from SDV.

• Runoff from Adjacent and Intermingled Areas: Applied ratings were based on the 

percentage of rock outcrop and shallow soils within a map unit.

• Soil Cover factors were based on vegetation burn severity maps, Worldview imagery and 

the forest vegetation layer. For post implementation soil cover, soil cover values were 

assumed to change little due to increases in activity fuels and cover recruitment from 

scorched crown. For the watershed treatment areas proposed for Alternatives 3 and 4, 

cover values were increased to 50% as proposed in management directions. It must be 
Rim Recovery Soil Report

44

recognized, however, that the 50% may not be attained in all cases due to lack of 

available material or fuel objectives not being met.

Erosion Modeling

The Water Erosion Prediction Program (WEPP) Disturbed WEPP batch program (Elliot 2010) was used to 

model predicted sedimentation resulting from the Rim Fire, salvage activities, and watershed 

treatments. Disturbed WEPP estimates erosion on an annual basis in contrast to WEPP ERMiT which is a 

strorm driven model that is useful during the Burned Area Emergency Response (BAER) assessment. 

WEPP is a physically based erosion model which incorporates topography, soils, climate, vegetation and 

management activity. Because of the size and complexity of the fire, modeled erosion outputs should 

not be used as absolute values. The purpose of using modeled values is to illustrate relative risk from 

existing and management activities and to evaluate the relative change in sedimentation associated 

with proposed activities. Three batch models were created to model post-fire (existing condition), 

watershed sensitive area treatments, and salvage logging effects not within watershed sensitive areas. 

Model inputs were derived as follows and specific attributes can be found in the WEPP batch 

spreadsheets located in the project record.

• Climate: A modeled climate was developed using Rock:Clim, the WEPP Climate simulator which 

modified the Hetch Hetchy climate station for climate conditions for the fire area.

• Soil: Soil texture and rock content inputs were acquired from the NRCS SDV and Official Soil 

Descriptions.

• Topography: Slope ranges were developed by using the 10 meter digital elevation model (DEM) 

with slope ranges represented by 10%, 30%, 50%, 70% and 90% slope inputs. Slope lengths and 

shapes were estimated using the DEM to associate slope ranges with topography.

• Treatment/Vegetation: 

o Existing condition: the treatment choice was based on the RAVG classification. If there 

was no change in canopy, the site was considered an unburnt site and a 20 year forest 

or shrubland was chosen depending on existing community. If there was a less than 

50% canopy change, the low severity fire was chosen for activity. If there was a 50-

100% change in canopy, high severity was used.

o Watershed sensitive areas post implementation: treatments were changed to short 

grass (Elliot 2013) in those areas with a 50-100%. When analyzed spatially, the 

watershed sensitive treatments replace the high burn severity salvage logging. All other 

values in the batch run are superfluous. 

o Salvage actions: For salvage logging operations a short-grass treatment was used (Elliot 

2013) regardless of burn severity.

• Cover:

o Existing conditions: Cover values for the existing condition are generally based on 

correlations between field observations and the RAVG burn severity. For low or 

moderated burn severities, soil cover tends to be between 90-100%. For low and 

moderate burn intensities, cover values were variable, but a conservative value of 30% 

were used, although during the time of implementation it is likely to be higher due to 
Rim Recovery Soil Report

45

soil cover storage in the canopy. For high burn severities, crews generally found little 

soil cover, especially effective soil cover. Because of standing stems and ongoing 

windthrow and branch breakage, 10% soil cover was used.

o Watershed sensitive areas post implementation: 50% cover was used based on 

management direction.

o Salvage actions: Soil cover was reduced by 20% (Elliot 2013) in all treatments except 

watershed sensitive area treatments where cover was increased to 50% and in areas 

with high intensity, cover values were increased to 20% to account for addition of 

activity materials.

SITE OBSERVATIONS

The goals of field observations were to identify soil properties useful in confirming the accuracy of the 

soil survey and to identify existing soil conditions to help analyze cumulative effects and understand soil

response to management. Field observations were also important to correlate the site conditions to 

remotely sensed data. 

Ninety seven plots were recorded. Site observation methods were developed for rapid assessment by 

field crews. Plot selection was stratified based on burn severity, soil type, topography, and visual 

satellite imagery expression. Site specific information collected by crews or remotely sensed in GIS 

include:

Topography: Topography is an important variable when determining erosion/runoff risk, soil moisture 

content, and ground cover associated with different plant communities. The following data was either 

gathered in the field or analyzed with digital elevation models on GIS.

• Slope magnitude and slope shape: As slope increases, the energy of flowing water increases, 

thereby increasing soil detachment and transport. Slope shape, whether concave, linear, 

convex, determines how water is concentrated along a hillslope.

• Aspect: The direction a slope faces determines the solar radiation of a hillslope. Plant 

communities and soil moisture drying rates and temperatures are influenced by aspect.

• Elevation: Elevation is a primary determinant on how much and what type of precipitation a soil 

receives and soil temperature. This influences runoff timing and intensity, plant communities, 

soil properties, and soil temperature.

Soil Parameters: Several soil parameters were observed to verify soil type and analyze for effects.

• Soil Texture: Most soil properties are dependent on soil texture, or the amount of sand, silt and 

clay. For this project, analysis of compaction and erosion were dependent on soil texture. This 

property was also used to verify soil type.

• Soil Depth: Water storage and potential erosion is dependent on soil depth. Field crews 

primarily looked at depth classes in the very shallow to deep range.
Rim Recovery Soil Report

46

• Rock content: The soils at observation points were broadly characterized as having greater than 

or less than 35% rock by volume in the upper 20 inches. The higher the rock content, the less 

prone a soil is to compaction but the higher the runoff and erosion rates are expected to be. 

• Rock Type: Rock type was broadly identified as granitic, volcanic, and sedimentary. This was 

used to help the soil scientist verify soil types.

• Identification of high runoff areas: Field crews noted the presence of high water runoff areas 

(shallow soils and rock outcrop). These areas were also identified by review of remotely sensed 

data. High runoff areas are important to recognize as potential initiation points of erosion in 

more productive soils downslope.

• Compaction intensity and disturbance extent: Field crews examined soil disturbance for 

compaction. Compaction was evaluated by examining soil structure. Categories included 

continuous platy structure indicating loss of soil productivity and soil hydrologic function, 

broken platy structure with vertical root penetration indicating past loss of soil productivity and 

soil hydrologic function but improving and functioning, and unaltered soil structure indicating 

little to no compaction. Observations were made on an existing disturbance with the 

assumption that ground not disturbed is not compacted.

Existing and potential soil cover. 

Soil cover is the most important soil characteristic estimate following a wildfire and any subsequent 

activities post fire. Observations were made to qualify the existing condition and to help watershed 

personnel correlate multi-spectral imagery with site characteristics. All values of cover were estimated 

in ranges to allow for rapid assessment.

• Standing non-commercial wood: The number of dead trees between 4 and 12 inches were 

estimated using a standard 1/10th acre plot sample. These trees were estimated to identify 

material that is available for use in cover either by natural recruitment or active recruitment 

using mechanical methods.

• Downed small (1-16”) and large (greater than 16”) wood greater than 10’ long: The amount of 

wood on the ground was estimated using a 117’ radius plot (1 acre). 

• Fine Soil Cover and Type: The percent fine soil cover was estimated visually and includes living 

and dead plant material. The quality of fine soil cover was also recorded and includes fresh 

needle fall, duff of mixed decomposition, mixed, straw, or chips.

• Potential cover type from harvested trees: A rating system was developed to estimate what type 

of cover is stored in the standing trees that meet the criteria for harvest. Descriptions include 

No Branches or Needles at the low end to Large and Fine Branches Present/Heavy Needle 

Present on the high end. 

• Rock Cover and Type: The amount of soil covered by rock fragments (2mm-24” in diameter) was 

visually estimated. 

• Bear Clover: Bear Clover is important soil surface stabilizing vegetation. Field crews noted the 

presence of pre-fire Bear Clover and whether it was sprouting post fire.
Rim Recovery Soil Report

47

REMOTELY SENSED DATA ANALYSIS

Analysis for this project utilized several remotely sensed sources of information to identify areas of both 

soil and vegetation burn severity, tree mortality, disturbances, and potential and existing covers. Unitby-unit ocular analysis was completed using each of the remotely sensed data sets. 

• Rapid Assessment of Vegetation Condition after Wildfire (RAVG): The Forest Service Remote 

Sensing Application Center (RSAC) produced a vegetation burn severity map based on changes 

in reflectance measured by LANDSaT satellite both before and after the fire. Values provided 

by RAVG proved to be a good indicator of existing soil cover and soil cover potential.

• Soil Burn Severity (SBS): Another product from RSAC, the SBS is a summary rating of soil 

condition post-fire, for the purpose of rapidly stratifying the burn area, identifying source areas 

of greater potential for runoff and erosion, and assisting other resource specialists in prioritizing 

where to spend limited field time. SBS is an integrative indicator of aboveground and

belowground fire effects, not merely a vegetative mortality rating. For this analysis, SBS was 

considered in EHR and erosion modeling with respect to structure alteration. However, in 

erosion modeling, soil cover values interpolated from RAVG were used.

• LiDAR: High resolution digital elevation model that was acquired in the fall of 2013. Standard 

DEMs used by the Forest Service have a resolution of 10 meters. LiDAR, however, has a 

resolution of 1 meter; a high enough resolution to see existing skid trails with constructed water 

bars. Figure 2 illustrates the relative differences between a 10 meter and a 1 meter DEM. Note 

the appearance of the skid trails with constructed water bars in the LiDAR imagery. Figure 2b 

illustrates an example of mechanical disturbance interpolated from LiDAR imagery.

Figure 2: Comparison of 10m DEM (left) to LiDAR derived 1m DEM (right)
Rim Recovery Soil Report

48

Figure 2b. Mechanical disturbance delineation. Color represents intensity.

 

• Worldview/Quickbird Satellite Imagery: High resolution multispectral imagery produced by 

DigitalGlobe (sample below). This imagery was extensively used to evaluate the need for 

watershed treatments and qualify potential soil cover. As seen in Figure 3, red top trees 

indicate healthy green vegetation that would not be harvested. Brown topped trees are dead 

trees with retained canopy and a substantial source of soil cover produced during needle fall. 

Black lines indicated in the imagery are dead trees with full combustion of needles, fine 

branches and often large branches; these areas are considered deficient in ground cover with a 

slow predicted recovery. Within the black areas, large woody materials consumed by the fire 

can be seen as white ash lines and patches.

Figure 3. Worldview imagery illustrating burn severity of the vegetation. Red indicating healthy canopy
Rim Recovery Soil Report

49

WATERSHED SENSITIVE AREAS (WSAs)

Watershed staff examined each unit of the alternatives for areas considered Watershed Sensitive Areas. 

Watershed Sensitive Areas are portions of the watershed that are at high risk of soil erosion and 

sedimentation due to the combined effects of the Rim Fire and potential recovery activities. . If postactivity soil cover is not greater than 50% in WSAs, cover additions through dropping non-commercial 

trees and lopping them into smaller pieces (drop and lop) or masticating the trees into chips or shreds 

would ensure ground contact.

Criteria for evaluating the existence of WSAs include: proposed recovery activities, burn severity, 

percent slope and slope shape, slope length, existing and potential soil cover, proximity to intermittent 

and perennial drainages, and proximity to high runoff response soils. 

The following criteria were evaluated as follows:

Proposed recovery activities: The identification of WSAs is dependent on the combined effects of the 

fire and recovery activities. Only treatment units where ground-based equipment is proposed were 

considered. This includes tractor units and helicopter and cable-yarding units where feller-buncher type 

equipment could be used for harvest activities. 

Burn Severity: The RAVG product was used as an initial stratification of site conditions. Canopy cover 

mortalities between 50 and 100% were considered as potentially deficient in soil cover. Both existing 

cover and immediate future cover recruitment is expected to be deficient.

Topography: The slope range of ground-based activities of 0-35% were considered in the identification 

of WSAs, however, delineations generally did not occur at slopes less than 15%. Below 15%, Erosion 

Hazard Ratings are considered moderate or below for all soil types. Bear Gully is the exception due to 

the identified extreme erosion potential of the terrace soils and the risk to the investment of past 

restoration activities. Slope shape strongly influences the degree that water concentrates. Slopes that 

are concave with the contour tend to concentrate water and increases risk that gullies may form below 

a burned slope. Slope length influences how much water can contributes to runoff and how much 

energy is accumulated from runoff. Some areas of high burn severity may not have much runoff 

potential because it burns in a mosaic, which tends to shorten slope lengths. Areas burned in a mosaic 

were not considered for treatments because the mosaic tends to act as filter areas.

Location of burned areas: The risk to forest resources such as water quality and soil productivity was 

considered. Most WSA treatments were identified in areas that had close proximity to intermittent and 

perennial streams so that threats to water quality from cumulative actions could be mitigated by the 

addition of additional ground cover. WSA treatments were also identified in areas where shallow, high 

runoff soils generally found on ridgetops were situated immediately upslope of large burned areas. 
Rim Recovery Soil Report

50

E. Erosion Hazard Rating: Units that exceed Moderate rating in greater than

15% of the unit (following page).
Rim Recovery Soil Report

51

A01A G03A O04 T27B A01B G12 O02A T27B A05C G14B O06 U01D

A01B G03B O05 T28 A03 G13A O02B U01B A08A G25 O07 U01DX

A02 G04 O06 U01 A04 G13B O03 U01C A08C G26 O08 U02

A03 G05 O07 U02 A05A G14A O04 U01D A09 H01 O09 U03

A04 G06 O08 U03 A05B G14B O05 U01DX A15 H02 O10A V01

A05 G07 O09 V01 A05C G25 O06 U02 AA01 H06 O11A V02

A08A G08 O10A V02 A08A G26 O07 U03 AA03 H09 O11B V03

A08C G09 O11A V03 A08C H01 O08 V01 AA04 H11 O11C V04A

A09 G10 O11B V04 A09 H02 O09 V02 AA07 H11X O201A V04B

A10 G11 O11C V05A A15 H06 O10A V03 AA08 H12 O201B V05B

A15 G12 O201 V05B AA01 H09 O11A V04A AA09 H12X P201 V10

AA01 G13 P201 V10 AA03 H11 O11B V04B AA11 H13A Q08 V13

AA02 G14A Q08 V13 AA04 H11X O11C V05B AA12 H13AX Q09 V13X

AA03 G14B Q09 V14A AA07 H12 O201A V10 AA13 H13B Q14A V14A

AA04 G25 Q14A V14B AA08 H12X O201B V13 B02 H13BX Q14B V14B

AA05 G26 Q14B V14C AA09 H13A P201 V13X B03 HT Q15 V14C

AA07 H01 Q15 V15 AA11 H13AX Q08 V14A B21 K01 Q16 V15

AA08 H02 Q16 W01 AA12 H13B Q09 V14B B22 K02 R01B W01

AA09 H03 R01A W02 AA13 H13BX Q14A V14C B22X L01 R04A W02

AA11 H04 R01B W03 B02 HT Q14B V15 B23 L02A R04B W03

AA12 H05 R02 W04 B03 K01 Q15 W01 B24X L02B R06A W04

AA13 H06 R03 W05 B21 K02 Q16 W02 B25X L02C R06B W05A

B01B H07 R04A W06 B22 L01 R01A W03 B32 L02D R07A W06A

B02 H08 R04B X01 B22X L02A R01B W04 C02 L02E R07B W06B

B03 H11 R06A X02 B23 L02B R02 W05A C03 L03 R12 X01A

B21 H12 R06B X03 B24X L02C R04A W06A C04X L04 R12X X01B

B22 H13A R07 X04 B25X L02D R04B W06B C05 L05A R15 X02

B23 H13B R08 X05 B32 L02E R06A X01A D01B L05B R16 X03

B24 HT R12 X06 C02 L03 R06B X01B D01C L07 R17X X04

B25 K01 R15 X07 C03 L04 R07A X02 D01E L201 R18 X05

B32 K02 R16 X08 C04X L05A R07B X03 D04A L202 R18X X06

B33 L01 R17 X09 C05 L05B R12 X04 D04B L203 R19A X07

C02 L02A R18 X10 D01A L07 R12X X05 D05 L204 R19B X08

C03 L02B R19A X100 D01B L201 R15 X06 D08 L205 R19D X09

C04 L02C R19B X101 D01C L202 R16 X07 D09 L206 R19DX X10

C05 L02D R19D X102 D01E L203 R17X X08 D11 M01 R19F X100

D01A L03 R19F X103 D04A L204 R18 X09 D12 M02A R20 X101

D01B L04 R20 X104 D04B L205 R18X X10 D13 M04A R22 X102

D01C L05A R22 X106 D05 L206 R19A X100 E03A M05A R23 X103

D01E L05B R23 X107 D08 M01 R19B X101 E03B M05B R24A X104

D04A L06 R24A X108 D09 M02A R19D X102 E04 M05C R25X X106

D04B L07 R24B X109A D11 M04A R19DX X103 E05 M05D R31 X107

D05 L202 R25 X109B D12 M05A R19F X104 F01 M05E R31X X108

D08 L203A R31 X109C D13 M05B R20 X106 F02A M05F R32 X109A

D09 L203B R32 X109D E01A M05C R22 X107 F02B M05G R33X X109B

D11 L204A R33 X109E E01B M05D R23 X108 F03 M06 R35A X109C

D12 L204B R35 X11 E02 M05E R24A X109A F11 M07 R35B X109D

D13 L205 R36 X110 E03A M05F R25X X109B F12 M08A R36 X109E

E01A L206 R37 X111 E03B M05G R31 X109C F13 M08B R37 X110

E01B M01 R38 X112 E04 M06 R31X X109D F14 M08C R38 X111X

E02 M02A S01 X114 E05 M07 R32 X109E F15 M08D R40B X112

E03A M04A S02 X115 F01 M08A R33X X110 F16 M08E S01 X114X

E03B M05A S03 X116 F02A M08B R35A X111X F17 M09 S02 X115

E04 M05B S04 X117 F02B M08C R35B X112 F18 M10 S03 X116

E05 M06 S05A X118 F03 M08D R36 X114X F19 M12 S04 X117

E06 M07 S05B X119 F11 M08E R37 X115 F20 M13 S06 X118

F01 M08A S06 X12 F12 M09 R38 X116 F21 M15 S08 X118X

F02A M08B S08 X120 F13 M10 R40B X117 F22A M16B S10 X119X

F02B M08C S10 X13 F14 M12 S01 X118 F22B M18 S11 X12

F03 M08D S11 X14 F15 M13 S02 X118X G01 M19 T01 X120

F11 M08E T01 X15 F16 M15 S03 X119X G01X M20 T02 X13

F12 M09 T02 X16 F17 M16B S04 X12 G02X M201 T03 X15

F13 M10 T03 X17 F18 M18 S06 X120 G03A M202A T04A X16

F14 M12 T04A X18 F19 M19 S08 X13 G03B M202B T04B X17

F15 M13 T04B X19 F20 M20 S10 X15 G04 M203 T04C X18

F16 M15 T04C X22 F21 M201 S11 X16 G05 M204 T04D X19

F17 M16B T04D X23 F22A M202A T01 X17 G06 N01A T04E X22

F18 M18 T04E X24 F22B M202B T02 X18 G07 N01B T20 X23

F19 M19 T20 X25 G01 M203 T03 X19 G08 N01C T21B X24

F20 M201 T21B X26 G01X M204 T04A X22 G08X N01D T23 X25

F21 N01 T23 X27 G02X N01A T04B X23 G09 N01E T23X X26

F22A N02 T24 X40 G03A N01B T04C X24 G10 N01F T24 X27

F22B N03 T25 X41 G03B N01C T04D X25 G11A N01G T25 X40

G01 O01 T26 Y01 G04 N01D T04E X26 G11B N01H T25X X41

G02 O02 T27A Y02 G05 N01E T20 X27 G11C N01I T26 Y01A

O03 Y03 G06 N01F T21B X40 G12 N01J T27A Y01B

G07 N01G T23 X41 G13A N02A T27AX Y01C

G08 N01H T23X Y01A G13B N02B T27B Y01D

G08X N01I T24 Y01B G14A N03 U01B Y02

G09 N01J T25 Y01C O03 U01C Y03A

G10 N02A T25X Y01D Y03B

G11A N02B T26 Y02

G11B N03 T27A Y03A

G11C O01 T27AX Y03B

Alternative 1 Alternative 3 Alternative 4