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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-9 Ground disturbance and vegetation removal can increase the potential for the introduction and spread of noxious weeds and invasive species (Olson 1999; Levine et al. 2003). Non-native plant invasions have the potential to change the composition and diversity of native plants through competition, altering the natural fire regime, and by changing ecosystem processes (e.g., nitrogen cycling). Construction of access roads and the movement of construction equipment and other vehicles along these roads would increase the potential for the spread of noxious weeds and invasive species in the affected areas (Sheley et al. 1999; Gelbard and Belnap 2003). Non-native plants, such as cheatgrass (Bromus tectorum), create a more continuous fuel bed than native bunchgrasses, resulting in an increase in fire frequency and intensity (Brown 2000; Paysen et al. 2000). See Section 4.12 - Wildland Fire Ecology and Management for more information on potential wildland fire impacts. RDFs would be implemented to minimize the spread of noxious weeds and invasive species from Project activities and include the following: reseeding disturbed areas with certified weed-free, land management agency-approved native or non-native species; washing all equipment before entering the Project area and when leaving areas where noxious weeds are present; closing or rehabilitating new or improved access roads that are not required for ongoing maintenance activities or by the land management agencies; developing and incorporating a Fire Protection and Control Plan into the POD; and complying with all federal, state, and county noxious weed control regulations and guidelines. In addition, a Noxious Weed and Invasive Plant Management Plan would be developed in consultation with land management agencies and local weed control districts and would be incorporated into the final POD. Riparian areas can be particularly vulnerable to disturbance. The removal of vegetation along waterways can cause an increase in water temperature, an increase water velocity, and decrease wildlife habitat. Disturbance of soil in or near riparian areas may lead to erosion of the streambank and increase the deposition of sediment into waterways. In addition, removal of protective vegetation could also expose soil to potential wind and water erosion. This can result in further loss of soil and vegetation, as well as an increase in sediment input to water resources. Impacts to soil and geology are discussed in Section 4.15 Soils and Geology, impacts to water resources are described in Section 4.14 Water Resources, and Section 4.3 Wildlife and Special Status Wildlife Species discusses impacts to wildlife. RDFs to reduce impacts to riparian areas include: avoiding riparian areas and wetlands, where possible, and minimizing disturbance to drainage channels and stream banks. Finally, indirect effects could result from the fragmentation of connected vegetation types. Fragmentation refers to the breaking up of the contiguous areas of vegetation into smaller patches, which results in the creation of habitat edges (i.e., areas where two or more vegetation types meet) along a ROW. Edge areas have different microclimatic conditions and structure, which may lead to different species composition than the interior area (Saunders et al. 1991). Edge effects are typically more dramatic in forest and woodland vegetation communities compared with shrubland and grassland communities. As plant communities become smaller and more fragmented, they become more susceptible to outside influences such as invasive weed species. Habitat loss, degradation, and fragmentation has already occurred in the Project area by other transmission lines, roads, highways and interstates, Joint Base Lewis-McChord Yakima Training Center (JBLM YTC) training operations, non-native plant invasions, fire, alteration by livestock grazing, and conversion of sagebrush steppe to residential and agricultural development (JBLM YTC 2002; Rice et al. 2008; Shaw et al. 1999). RDFs would be implemented during construction, operation, and maintenance and are anticipated to be effective at reducing further degradation of habitat. RDFs include: minimizing the blading of native plant communities during construction, consistent with safe construction practices; utilizing existing roads where possible; implementing noxious weed and invasive plant control measures that would be developed as part of a Noxious Weed and Invasive Plant Management Plan that will be incorporated into the final POD; closing or rehabilitating new or improved access roads that are not required for ongoing maintenance activities or by the land management agencies; and reseeding disturbed areas with certified weed-free native or other acceptable species as detailed in the Reclamation, Revegetation, and Monitoring Plan.