Lost Bear Timber Sale EA - Attachment B 



late into the spring Erosivity is moderate and can be controlled with standard drainage features These 

 soils have a limited dry season of use. 



SECTION 36 T14N, R14W 



Predominate soils in the proposed harvest area are Evaro and Winkler gravelly loams on moderate 

 slopes to steep slopes Evaro soils have a silt loam volcanic ash surface over deep very gravelly loams 

 from quartzite and argillites. Evaro soils occur mainly on north and easterly aspects and support 

 lodgepole and larch stands in the section These soils are well drained, but are sensitive to rutting and 

 compaction if operated on in the spring. Winkler soils are similar but without an ash surface and a longer 

 season of use Primary soils concerns are avoiding compaction and displacement of shallow ash surface 

 soils during skidding and slash disposal. The slopes up to 45% are well suited to tractor operations. 



ENVIRONMENTAL EFFECTS ON SOILS 



The No-action alternative would have little effect on soil resources. Existing roads with inadequate 

 drainage will continue to erode without maintenance. Existing skid trails that are revegetating, will 

 continue to slowly stabilize. 



Harvest Effects of action alternative: 



The pnmary risks to long-term soil productivity (quality) are erosion, rutting, compaction and 

 displacement of surface soils by equipment operation and road construction. 



Equipment operation will be limited to moderate slopes and periods when soils are dry, frozen or snow 

 covered to minimize the area and degree of detrimental soil effects. Wet sites and steep slope will have 

 equipment restriction zones. Erosion on skid trails, landings and roads can be controlled by standard 

 drainage practices. 



Cumulative effects can occur from repeated entries into the harvest area. Past harvest in section 36 has 

 left some effect on the soils, with main skid trails still evident. Skidding and slash disposal mitigation 

 measures will limit the area impacted and therefore present low risk of cumulative effects assuming 

 future stand entries would likely use existing trails and landings. 



HARVEST DESIGN MITIGATION MEASURES: 



Potential soil impacts can be avoided or reduced to acceptable levels by implementation of BMP'S and 

 the following recommendations 



* Tractor skidding will be limited to slopes less than 40% on the granitic Ambrandt, Elkner and Ovando 

 soils in section 14. The logger and sale administrator will agree to a general skidding plan prior to 

 equipment operations to limit area in trails and protect residual trees. Designate skid trails on steeper 

 portions of units. Use existing trails wherever possible. Skidding will be limited to 45% on all other sites. 



* Limit equipment operations to periods when soils are relatively dry, (less than 20%) to minimize soil 

 compaction, rutting, and maintain drainage features Check soil moisture conditions prior to equipment 

 start-up! Some moister conditions are accepted on harvest units where tractors remain on designated 

 trails and timber will be winched to trails. 



* Localized moist sites within harvest units will be protected by equipment restriction zones where need- 

 ed and winch trees out. 



* Slash Disposal- Harvest and slash disposal treatments will retain 10-15 tons/acre large woody debris 

 and a majority of fine slash well distributed for nutrient cycling and long-term productivity This can be 

 accomplished by in-woods processing or return skidding slash concurrent with harvest operations. On 

 areas of high slash concentration the forest officer would approve the most appropriate treatment from 

 the following options. 1 ) Lop and scatter slash, 2) excavator pile and redistribute slash as needed on 

 slopes up to 50% 3) Dozer pile with slash blade on slopes up to 30% using caution to avoid excessive 



