Botany and Wetlands Study Report - McMillen, LLC

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Botany and Wetlands Study ReportSoutheast Alaska Power AgencyAs described above, the project analysis area includes a narrow perimeter of land around SwanLake and a stretch approximately 0.8 mile along Lost Creek extending up the banks to anelevation of 350 feet. Most of the lake perimeter, including the banks of the four main creeksentering the lake, is characterized by very steep forested slopes. Rock outcrops, avalanchechutes, and waterfalls also occur along the lake perimeter (Appendix C). The vegetation growingon the steep slopes is primarily coniferous forest with a dense shrub understory. Shrublands andareas of herbaceous vegetation typically occur in or adjacent to avalanche chutes and waterfalls.In addition to forest and shrublands, there is a riparian vegetation community associated withLost Creek. Various wetland types are also found dispersed throughout the analysis area (seeSection 4.2 below). Plant communities in the analysis area are largely unaltered by humanactivity.3.2 Sensitive PlantsA total of 18 plant species and one lichen have been designated as Sensitive on the AlaskaRegional Forester’s list; 16 of these are known or suspected to occur on the Tongass NationalForest (Appendix A). Of the species with habitats similar to those present within the Swan LakeExpansion analysis area, three of these species have been documented on the Ketchikan‐MistyFiords Ranger District. The Ketchikan‐Misty Fiords Ranger District is also within the potentialrange of an additional five species, which are suspected to occur on the District. Table 1summarizes the general habitat requirements of the eight plant species that are either known tooccur or suspected to occur on the Ketchikan‐Misty Fiords Ranger District and for whichpotential habitat may be present within the analysis area. No populations of sensitive specieswere located during surveys of the analysis area.3.3 Rare PlantsThe target rare plant species list for this project is the AKNHP 2012 Rare Vascular Plant List(Appendix B). The list includes species with a State Ranking of S1, S2, and S3. As noted earlier,the list changes periodically with plants added or dropped as additional information on plantviability, distribution, and taxonomy is learned. Even though boreal bedstraw (Galiumkamtschaticum), broadlipped twayblade (Listera convallarioides) and Choris’ bog‐orchid(Platanthera chorisiana) are not included on the 2012 AKNHP Rare Vascular Plant List, they areconsidered species of interest for the Tongass National Forest.Populations of two rare plant species: northern bugleweed (Lycopus uniflorus) and Pacificbuttercup (Ranunculus pacificus), were found during surveys within the analysis area (Figure 2;Table 2). Additionally, populations of five plant species: boreal bedstraw (Galiumkamtschaticum), Choris’ bog‐orchid (Platanthera chorisiana), maidenhair spleenwort (Aspleniumtrichomanes ssp. trichomanes), brightgreen spleenwort (Asplenium trichomanes‐ramosum), andbog adder’s‐mouth orchid (Malaxis paludosa) that were on the AKNHP 2008 Rare Vascular PlantList (AKNHP 2008) but were subsequently removed were found in the analysis area or as noted,just outside of the analysis area (Table 2).Swan Lake Hydroelectric Project January 2013FERC Project No. 2911 Page 9 Version: Agency Review
Botany and Wetlands Study ReportSoutheast Alaska Power AgencyTable 1. Known or Suspected Sensitive Plants in the Ketchikan‐Misty Fiords Ranger DistrictScientific Name Common Name Presence 1/ HabitatBotrychium spathulatum Spatulate moonwort Suspected Maritime and upper beach meadows,well drained open areas, limestone,alpine habitats, disturbed areasCirsium edule var. macounii Edible thistle Known Moist to mesic meadows, open forests,talus slopes, in subalpine to alpine areasCypripedium montanum Mountain lady’s slipper Suspected Open forest, beach meadows, peatlands,wet meadowsCypripedium parviflorum var.pubescensLarge yellow lady’sslipperSuspected Peatlands, occ. on limestone substrates,open forested habitats, dry meadowsLigusticum calderi Calder’s lovage Suspected Limestone, wet to moist sites in thesubalpine and alpine, rock habitatsPiperia unalascensis Alaska rein orchid Suspected Forested areas, dry to mesic meadows,roadsides and forest/ muskeg edges,streamsidesPlatanthera orbiculataLesser round-leavedorchidKnownA variety of habitats, most commonly inforested habitats and along the forestedmuskeg edge. Found in both old andyoung growth.Polystichum kruckebergii Kruckeberg’s swordfern Known Sheltered cracks in ultramafic outcrops1/ Known -- known to occur in the Ketchikan-Misty Fiords Ranger District.Suspected -- suspected to occur in the Ketchikan-Misty Fiords Ranger District.Table 2. Rare Plants Observed within the Analysis AreaCommon NameMaidenhairspleenwort 1/Brightgreenspleenwort 1/BorealGaliumbedstraw1/, 2/NorthernbugleweedBog adder’smouthorchid 1/Scientific NameAspleniumtrichomanesssp.trichomanesAspleniumtrichomanesramosumkamtschaticumLycopusuniflorusMalaxispaludosaGlobalRank/StateRank Typical Habitat Population Location in the Analysis AreaG5 / S4G5 / S4G5 /S4 2/,3/G5 /S3S4 3/G5 / S4Cliffs, dry to mesicnon-limestone rocksCliffs, dry to mesicrocksMoist woods,thickets, meadowsWet meadows,streambanks,roadside ditchesOpen Sphagnumbogs, swampywoodsMarshes, thicketedges, wet habitatsAlong streams and1 population (2 small sub-populations)along the north shore of Swan Lake; anadditional population is located along anexisting road in the project area but is not inthe analysis area.1 small population along an existing road inthe project area road, which is not in theanalysis area.1 population along a stream terrace of LostCreek.2 populations; 1 scattered around shore ofSwan Lake and 1 along an existing road inthe project area but is not in the analysisarea.1 small population; in muskeg on southshore of Swan Lake.Choris’bog-orchid1/, 2/PlatantherachorisianaG3G4 /S4 3/1 small population; in muskeg on shore ofSwan Lake.Pacific buttercup Ranunculus G31 small population in the Lost Creek area.pacificus /S3S4 meadows1/ Species listed on the 2008 AKNHP Rare Vascular Plant List but dropped from the 2012 list (AKNHP 2008; AKNHP2012).2/ Not included on the 2012 AKNHP Rare Vascular Plant List but considered species of interest for the Tongass NF.3/ Indicates that the rank is preliminary (AKNHP 2012) Sources: Hitchcock and Cronquist 1973; Hulten 1968.Swan Lake Hydroelectric Project January 2013FERC Project No. 2911 Page 10 Version: Agency Review
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