Botany and Wetlands Study Report - McMillen, LLC

Botany and Wetlands Study ReportSoutheast Alaska Power Agencythese acidic, wet, low‐nutrient environments (EPA 2011). Soils in moss muskegs are typicallyorganic peat deposits that accumulate over unconsolidated glacial till or impermeable glacialsilts, typically on gentle or nearly level slopes. Moss muskegs often have no significant inflow oroutflow of water other than precipitation, thus ponded areas, a result of a high water table,occur within the wetland. These wetlands function as areas of surplus water and peataccumulation creating a stable microclimate and habitat for waterfowl and wildlife, includingcranes, black bear, amphibians, mink, and deer. In the analysis area, one moss muskeg wasobserved north of Track Creek on the southwestern shore of Swan Lake (Figure 4). Plantsobserved in this wetland included small cranberry (Vaccinium oxycoccos), bog blueberry(Vaccinium uliginosum), alpine laurel (Kalmia microphylla ssp. occidentalis), bog Labrador tea(Ledum groenlandicum), cottongrass (Eriophorum spp.), sundews (Drosera spp.), threeleafgoldthread (Coptis trifolia), smoothstem sedge, few‐flowered sedge (Carex pauciflora), tuftedbulrush (Trichophorum cespitosum), sphagnum moss (Sphagnum spp.) and scattered stuntedtrees including lodgepole pine (Pinus contorta), red alder and Sitka alder. Approximately, 1.5acres (1.1 percent) of the analysis area consists of muskeg habitat.4 PROJECT EFFECTSThis section describes the direct and indirect effects on rare and sensitive plants, generalvegetation, and wetland resources from the proposed action.Direct and indirect effects are estimated for rare and sensitive plants based on the impacts toknown populations and suitable habitat from the proposed project analysis area. Direct andindirect effects for general vegetation and wetland resources are estimated based on the acresof the analysis area that would be temporarily or permanently impacted by the proposedproject.4.1 Identified Issues and Concerns for Sensitive PlantsThree sensitive plant species with potential habitat in the Swan Lake Expansion analysis areahave been documented on the Ketchikan‐Misty Fiords Ranger District (edible thistle, lesserround‐leaved orchid, and Kruckeberg’s swordfern). Five sensitive plant species with potentialhabitat in the analysis area are suspected on the Ketchikan‐Misty Fiords Ranger District(spatulate moonwort, mountain lady’s slipper orchid, large yellow lady’s slipper orchid, Calder’slovage, and Alaska rein orchid) (Table 1). These eight species, and the potential project effects,are briefly described below. Although they have the potential to occur in the analysis area, noneof these species were located during field surveys of the analysis area associated with the SwanLake Expansion Project.Swan Lake Hydroelectric Project January 2013FERC Project No. 2911 Page 17 Version: Agency Review