Environmental Assessment

AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3
To measure the impacts of the proposed actions under each of the two action alternatives, or in the case of
the No Action Alternative, the lack of action, the following issue measures were applied.
1) Change in extent of detrimental soil conditions following proposed harvest and mitigation
treatments within the individual activity areas proposed for vegetation and fuel reduction
treatments.
2) Amount of coarse woody material (CWM) and surface organic matter that would likely be retained
to protect mineral soil from erosion and provide both short and long-term nutrient supplies for
maintaining soil productivity on treated sites (Soils Report page 4).
Scope of the Analysis
The soil resource may be directly, indirectly, and cumulatively affected within each of the activity areas
proposed within the project area. An activity area is defined as “the total area of ground impacted
activity, and is a feasible unit for sampling and evaluating” (FSM 2520 and Forest Plan 4-71). Activity
area boundaries are considered to be the smallest identified area where the potential effects of different
management practices would occur. Thus, the discussion of soil effects and soil quality standards focuses
primarily on the units proposed for silvicultural and fuel reduction treatments (Soils Report page 4).
Quantitative analyses and professional judgment were used to evaluate the issue measures by comparing
existing conditions to the anticipated conditions which would result from implementing the action
alternatives. This analysis also considered the effectiveness and probable success of implementing the
management requirements, mitigation measures, and Best Management Practices (BMPs) which are
designed to avoid, minimize or reduce potentially adverse impacts to soil productivity.
For the purposes of this analysis and discussion, short-term effects are defined as changes to soil
properties that would generally revert to pre-existing conditions within 5 years. Long-term effects are
those changes that would remain for periods of five (5) years or longer (Soils Report page 5).
Environmental Effects
Alternative 1 - There would be no change in current levels of detrimental soil impacts present in the
planning area. Such impacts are primarily associated with timber management activities that occurred
between 1974 and 1997. During that time period, 5,248 acres were treated with a variety of silvicultural
treatments. This included the construction and use of temporary roads, log landings, and primary skid
roads. The amount of detrimental impacts associated with these existing logging facilities is estimated at
approximately 956 acres.
This alternative would defer opportunities for soil restoration treatments that reduce the extent of existing
impacts and help move conditions toward a net improvement in soil quality (Soils Report, page 22). The
amount of detrimentally disturbed soil associated with existing logging facilities is included in estimated
amounts of detrimental soil conditions in Table 3-28.
The planning area was originally ground-based railroad logged during the 1930s; visual evidence of
logging facilities from that period is difficult to locate due to the abundance of vegetation and forest litter.
The low bulk density and low compaction potential associated with volcanic ash soils has resulted in
natural processes – freeze thaw cycles, revegetation, etc. – having restored or continuing to restore soil
quality on these sites over time. Therefore, these impacts are not included in the estimated impacts of
past activities (Soils Report page 9).
There are approximately 297 miles of system roads occupying an estimated 474 acres which have
converted soils to a non-productive condition. No new roads would be constructed and no system roads
would be closed or decommissioned under this alternative. There would be no change in either the
number of miles of roads or the number of acres converted to a non-productive condition.
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