Final Environmental Impact Statement

Vestal Final Environmental Impact Statement Chapter 3
reduce the potential spread of MPB to forested stands on private land as well as National
Forest. Sanitation cuts would be done for up to five years in each stand if necessary to
remove newly infested trees. The proposed action acknowledges the fact that no amount
of treatment would completely eliminate the threat of MPB infestation, however
treatments such as those in the proposed action, would reduce that threat more than the
No Action alternative.
All commercial entries would be limited by operability and access limitations resulting in
something less than the total acres planned being actually treated with commercial
harvest. This would amount to no more than 12% of the planned commercial treatment
acres.
The result of this alternative is a lowered risk level and a decreasing level of MPB caused
mortality relative to the current epidemic (Table 29). The landscape is expected to
encompass thinned stands, some very open stands, and some openings as a result of the
varying levels and concentrations of infested trees. Aspen clones would increase in size
and viability as conifers are removed in and around them. As the infestation is slowed in
the treated stands, areas left at higher densities for wildlife habitat would be more likely
to avoid levels of mortality that reduce their structural stage condition.
Prescribed burning has little effect on the site structure following mechanical treatments
that create SS 3A or 4A. However, prescribed burning in combination with drought can
stress residual trees in mechanically-treated areas and leave them susceptible to mountain
pine beetle-caused mortality. Therefore prescribed burning would be delayed until after
mechanical treatments are completed and following the passing of the mountain pine
beetle epidemic.
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Table 27. MPB Risk Rating - Alternative 2 Compared to Existing Condition
Mountain Pine Existing Existing Alt 2 Alt 2
Beetle Risk Acres Percentage Acres* Percentage
Low 9,320 39 20,498 87
High 14,373 61 3,069 13
*Total acres of pine is reduced in Alternative 2 due to hardwood conversion treatment
Thinning treatments would increase growth on remaining trees and improve the overall
health of the stands because there would be more water, nutrients and sunlight for each
tree. Thinning can put stands at risk to windthrow and breakage, particularly where
drastic changes in density result. The potential for windthrow and breakage would be
minimized by thinning from below, i.e. harvesting mostly the smaller, shorter trees and
leaving the tallest trees that have had more wind exposure and developed more
sturdiness. This alternative would not be expected to result in a marked increase in
windthrow or breakage and it would be less than in Alternative 1.
Managed healthy stands would maintain options for future forest management. Some
reproduction of seedlings can be expected over time after thinning. This change in forest
structure may be treated in future entries with prescribed burns or mechanical treatments
to eliminate seedlings. Conversely, overstory removals, regeneration cuts or uneven-aged
treatments may be prescribed to enhance or maintain the diversity in structure that is
developed.