TABLE 3-3: Soil Interpretations for Fish Creek Complex Project Area 



Complete descriptions of the soils in the burned area are found in the Lolo National 



Forest- Land System Inventory (USFS 1989). 



The 60QC soils primarily on north aspects with volcanic ash surface soils and 

 tend to be more productive soils supporting ponderosa pine and Douglas fir, with 

 lesser areas of western larch and lodgepole pine. By contrast, north and easterly 

 aspects tend to have deeper soils, higher moisture and nutrient retention, and 

 associated (moderate) productivity. Primary concern for soil productivity is 

 maintaining the shallow topsoils by minimizing displacement, controlling erosion, 

 and retaining a portion of woody debris for long term nutrient cycling. Both map 

 units have moderate erosion risk that requires cable harvest or winch line skidding 

 to existing roads to avoid excessive disturbance. 



Map unit I3UA soils form the broader well drained stream terraces and alluvial 

 fans along Fish Creek, Thompson Creek, and Deer Creek drainages. These deep 

 soils are typically well drained supporting ponderosa pine and Douglas fir. Map 

 unit lOU includes the alluvial bottoms and flood plains adjacent to streams. 



Narrow alluvial deposits occur adjacent to Fish Creek, Thompson, Deer Creek, 

 and the smaller tributary creeks. These alluvial deposits are somewhat poorly 

 drained and seasonally wet supporting riparian species (willow, dogwood, and 



Fish Creek Salvage Environmental Assessment 



3-11 



