Final Environmental Impact Statement
Final Environmental Impact Statement
Final Environmental Impact Statement
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Vestal <strong>Final</strong> <strong>Environmental</strong> <strong>Impact</strong> <strong>Statement</strong> Chapter 3<br />
management area, per the 2009 Black Hills Monitoring and Evaluation Report (USDA<br />
Forest Service 2010). Based on this data the objective is currently exceeded in MAs 4.1<br />
and 5.1 and is near achievement in MA 5.4.<br />
Table 17. Existing Percentages of Very Large Sized Pine Acres by Management Area<br />
Forest-Wide MA<br />
Objective<br />
MA 4.1 - Existing MA 5.1 - Existing MA 5.4 - Existing<br />
36<br />
10% 20% 13% 9%<br />
The Vestal project area contributes to these forest-wide percentages. Currently, there are<br />
approximately 974 acres of SS4 pine which have an average tree size of very large in the<br />
Vestal project area. These stands are located in all three of these management areas.<br />
There are approximately 50, 208 and 716 acres of pine stands with an average tree size of<br />
very large in MAs 4.1, 5.1 and 5.4, respectively.<br />
Late Succession<br />
Late succession, or structural stage (SS) 5, is defined in the Forest Plan glossary as<br />
follows: “This structural stage is characterized by very large trees (16+ inches dbh).<br />
Trees are at least 160 years in age….Late succession ponderosa pine may occur in dense<br />
stands, but may also grow in the open or in park-like stands” (Mehl 1992).<br />
Forest Plan direction for SS5 is included in the management area objectives, as discussed<br />
earlier. The Vestal project area contains approximately 107 acres of identified late<br />
succession (SS5) pine forest in the project area and contributes to the existing forest-wide<br />
percentages for MA’s 4.1, 5.1 and 5.4. Late succession forest is at high risk for MPB<br />
infestation and a very high fire hazard rating.<br />
Currently there are approximately 10,267 acres of SS4B and approximately 2,700 acres<br />
of 4C in the project area; these stands would be available to grow into older, denser late<br />
successional stands. These stands would also be susceptible to morality from MPB<br />
infestation and wildfire. An additional 1,270 acres of SS3B (low MPB risk) would also<br />
be available to grow into SS5 stands in the future as additional replacement stands.<br />
Mountain Pine Beetle<br />
There is currently a mountain pine beetle epidemic occurring within the project area<br />
(USDA Forest Service 2011b, also Appendix H). All measures of beetle activity indicate<br />
a rapidly exploding beetle situation with a significant increase in tree mortality over the<br />
past three years (Allen 2011a). Stand conditions across the project area are largely (61%)<br />
at high risk to increasing mountain pine beetle caused mortality (Table 18). Combine the<br />
high stand hazard with the high risk of a large resident beetle population in place would<br />
indicate that tree mortality is going to keep increasing and likely increase at a rapid level.<br />
For a dramatic depiction of how quickly MPB caused mortality is occurring in this<br />
project area refer to the two pictures on page 2, Chapter 1, which dramatically display<br />
changes over a two year period.<br />
Tree mortality from mountain pine beetle is most evident in the northern and western<br />
portions of the project area, at this time. Field surveys completed in the fall of 2011<br />
indicate that approximately six trees were infested by MPB in 2011 for every single tree