Environmental Assessment

AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3
Table 3-28 summarizes current (Alternative 1), post-harvest, and post-rehabilitation detrimental soil
conditions within proposed vegetation treatment units under both Alternatives 2 and 3. It does not
include any detrimental soil impacts associated with fuel reduction activities outside of vegetation units or
reforestation activities as described previously. These activities would be accomplished without utilizing
mechanized harvest equipment, or in the case of fuel reduction units, would utilize equipment with
relatively low ground pressures and require two (2) or fewer passes to accomplish the work. It does
include roads, water sets, or other existing detrimentally impacted soils if those sites are included within
the treatment (activity) unit boundary. Unit by unit soil conditions are described in the Tables B-1
(Alternative 2) and B-2 (Alternative 3) in Appendix B. The following discussion provides further
summary discussion of the impacts of harvest activity in proposed harvest units.
Table 3-28 Projected Levels of Detrimental Soil Impacts by Alternative Following Timber Harvest Activity and
Subsoiling
Levels of
Detrimental Soil
Conditions
Existing Condition
(Alternative 1)
Following Harvest
Post-Project Condition
Following Subsoiling
Mitigation
Alternative 2 Alternative 3
Detrimental Soil Conditions Detrimental Soil Conditions
20% Total 20% Total
66 units
142 Ac.
61 units
834 Ac.
67 units
867 Ac.
4 units
77 Ac.
9 units
157 Ac.
3 units
66 Ac.
3-97
70 units
219 Ac.
70 units
991 Ac.
70 units
933 Ac.
75 units
221 Ac.
64 units
883 Ac.
72 units
1,101 Ac.
1 unit
58 Ac.
9 units
218 Ac.
1 units
53 Ac.
73units
279 Ac.
73 units
1,101 Ac.
73 units
1,154 Ac.
The analysis indicates that, to provide access to harvest units and facilitate ground-based logging
activities, Alternative 3 would result in 121 acres more soil disturbance following subsoiling mitigation
than would Alternative 2.
Alternative 2 proposes harvest activities on approximately 6,480 acres. Of this total, ground-based
equipment would be used in 70 harvest units totaling 6,451 acres. Approximately 29 acres in two units
(units P1, P2) would be treated without the use of ground-based equipment.
Within the 70 units proposed for harvest using ground-based equipment, there are an estimated 219 acres,
or approximately 3.4 percent of the proposed treatment acres, of detrimentally disturbed soil within 58 of
those 70 units. This includes logging facilities from past timber management activities in addition to sites
associated with other management facilities (water sets, OHV trails, etc.). This includes four (4)
proposed units, H07, H38, H41, and P04, which have pre-harvest detrimental soil conditions in excess of
20 percent of the unit area (Appendix B, Table B-1). Following harvest activities, the acreage of
detrimentally impacted soils would increase to approximately 991 acres, an increase of 772 acres, or
approximately 15.4 percent of the harvest acres. Detrimental soil conditions would remain at or below
the LRMP standard within 61 of the harvest units. Detrimental soil impacts would exceed 20 percent of
the unit area in the remaining nine (9) units (H02, H07, H19, H36, H38, H40, H41, P04, and P19).
Portions of 12 units would receive subsoiling treatments to rehabilitate 58 acres of detrimentally
compacted soil associated with roads, log landings and main skid trails. This would include the nine units
that are expected to exceed the LRMP standard plus three (3) additional activity areas (H10, H23, and
H28) where short segments of existing road would be decommissioned following project activities. The
analysis predicts that five (5) of the 12 units in which subsoiling would be applied would see a decrease in
the area associated with detrimental soil impacts (H07, H19, H38, H41, and P04). The remaining seven