Environmental Assessment

ALTERNATIVE DESCRIPTION – ALTERNATIVE 2 – PROPOSED ACTION CHAPTER 2
percent of the unit area upon completion of harvest activities and/or machine piling of slash (unit H19).
Three (3) of those units; H07, H38, and H41, currently exceed the 20 percent detrimental soil standard
(Table 3-4, Soils Report). Thirty-three (33) acres would be subsoiled to reduce detrimental soil impacts
to or below the 20 percent standard, or in the case of the three units that currently exceed the standard, to
a level below the existing level. Subsoiling would be accomplished using a D6 or comparable crawler
tractor pulling a winged subsoiler to a maximum depth of 24 inches.
Units H10, H23, and H28 are also proposed for subsoiling even though post-harvest detrimental soil
impacts are not projected to exceed the 20 percent standard (Table 3-4, Soils Report). Approximately two
(2) acres would be subsoiled in units H10 and H23, primarily to obliterate and decommission system
roads. Approximately 14 acres would be subsoiled in unit H28 to rehabilitate logging facilities (skid
trails and landings) following shelterwood harvest in unit H28. In thinning units these facilities would be
retained for future use; no such use is expected in unit H28 in the next 30 years.
Non-commercial harvest could be accomplished with either the use of the same or similar types of
mechanized equipment to fall and remove the material if commercial markets develop for some or all of the
material or by hand felling and leaving on site. Where mechanized equipment was not used, all felling
would be accomplished by hand using chain saws. Mechanized equipment would not be used in units P1
and P2.
Assuming that machinery is utilized to harvest small diameter trees, two (2) additional units; P04 and
P19, are projected to exceed the 20 percent standard upon completion of management activities. P04
currently exceeds the 20 percent standard; P19 does not (Table 3-4, Soils Report). A total of 10 acres
would be subsoiled to reduce detrimental impacts. In unit P19, subsoiling would reduce the level of
detrimental impacts to 20 percent. In Unit P04, subsoiling would reduce the level of detrimental soil
impact to 23 percent or two (2) percent below current levels.
Fuels Reduction Treatments in Xeric Shrublands and Forest Stands (20,170 acres)
This alternative also proposes fuel reduction treatments on an additional 20,170 acres. Proposed
treatments would reduce the risk of a wildfire damaging or destroying structures at the Pine Mountain
Observatory, the facilities at the Antelope and Pine Mountain electronic sites, and the Bonneville Power
Administration (BPA) substation in the Sand Springs Area. Treatments along Roads 18, 23, and 2017,
major travel routes within the planning area, would improve safety for visitors and firefighters entering
and leaving the planning area. All treatments would reduce fuel loadings and break up vertical and
horizontal fuels, reducing the risk of crown fires as well as the risk of a large scale, high intensity wildfire
fire adversely affecting other resource values including wildlife habitat and cultural resources.
A total of 9,553 acres would include pretreating by the falling of all trees four (4) inches dbh and smaller
using chain saws and then underburning. Ignition would be by hand.
A total of 147 acres (units F28, F29, F31, and F40) along Roads 18 and 23 would be pretreated by felling
all trees four (4) inches dbh and smaller followed by machine piling the slash in random locations using a
ground based tractor with a brush rake. All piles would be burned and residual vegetation mowed.
Vegetation height after mowing would be at least six to eight (6 to 8) inches in height. These units are all
located along primary travel routes and would help to provide safe travel routes.
A total of 2,140 acres would be pretreated by falling all trees less than four (4) inches dbh followed by
machine piling, burning of the piles, and underburning. No hand or machine fireline would be
constructed.
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