SBCT Final EIS - Govsupport.us

Chapter 5 – Environmental Consequences5.2.10.4 Impacts from Maneuver TrainingSignificant Impacts Mitigable To Less Than SignificantImpact 6: Introduction and spread of invasive plants and noxious weeds. Military activities increasethe threat of spreading noxious weeds through training and increased use of roads and trails.Maneuver training would occur at SBMR, DMR, KTA, and PTA. Brigade- and battalion-leveltraining would primarily occur at PTA, and the frequency of maneuver training at PTA is notexpected to increase above existing levels. The Keamuku Parcel would be used for maneuver trainingas well, and would remain a nonlive-fire area. Platoon- and company-level training would primarilyoccur at the other areas, and would increase in frequency; however, SBCT maneuver trainingtypically covers a larger area, potentially extending training into areas that have not been used asfrequently. Additionally, roads and trails, including Helemano Trail, Dillingham Trail, and DrumRoad, would be improved and use would increase. Maneuver training under Alternative A would beexpected to affect the introduction and spread of invasive species at SBMR, DMR, KTA, and PTA inthe following ways:• Movement of troops and equipment across the landscape would increase the likelihood ofnonnative plant introductions;• Disturbance of native vegetation creates an open ecological niche that nonnative plants caninvade;• Fires would put native plant species at competitive disadvantage.Regulatory and Administrative Mitigation 6: Impacts from noxious weeds from maneuver trainingwould be significant, but mitigable to less than significant. Mitigation measures are the same as thosedescribed previously under Impacts from Range Construction.Impact 7: Impacts to Threatened and Endangered Species. Following the establishment of HelemanoTrail, Dillingham Trail, and Drum Road, units would transport materials and equipment on theseimproved routes. Additionally, the military vehicle trail between Kawaihae Harbor and PTA would beimproved and extended to provide off-highway transport of vehicles, personnel, and equipment. Thiswould result in direct and indirect effects on listed species and their critical habitat by potentiallycausing the take of federally listed species and the degradation of critical habitat. A wildfire coulddamage special status plant and wildlife communities. The presence of large, loud vehicles wouldlimit wildlife migration and would interrupt corridors for natural dispersal of species among theseareas. Dust, soil erosion, and runoff would continue to affect the areas that surround the roadadversely, including valuable freshwater resources. The loss in habitat value occurs primarily in thoseareas surrounding the trails that are exposed to increased noise, car fumes, general activity, andinvasive species, and areas downstream that are subject to runoff and erosion problems.Regulatory and Administrative Mitigation 7: All species management in regards to impacts would befollowed as described the Oahu and Hawaii Biological Opinions (USFWS 2003c and USFWS2003d). Additional mitigation measures that would be implemented by the Army are discussed inMitigation 1 above.Less Than Significant ImpactsImpacts to vegetation. Maneuver training would occur at SBMR, DMR, KTA, and PTA. Brigade- andbattalion-level training would primarily occur at PTA, but the frequency of maneuver training at PTAis not expected to increase above existing levels. The Keamuku Parcel would be used for maneuverFebruary 2008 5-52 2/25th SBCT Final EIS