Alaska Department of Transportation & Public Facilities. Seward Highway, MP 75-90, Ingram Creek to Girdwood BR-BH-NH-OA3 (35) / 58105

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3 Alaska Department of Transportation & Public Facilities Seward Highway, MP 75-90, Ingram Creek to Girdwood BR-BH-NH-OA3 (35) / Vegetation Study March 2008 Prepared by: HDR Alaska, Inc C Street, Suite 305 Anchorage, Alaska 99503

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5 TABLE OF CONTENTS 1.0 Introduction and Purpose Project Environment Project Location Climate Geography and Geology Vegetation Methods Results and Discussion Forest Cover Types Open Sitka Spruce Forest Closed Balsam Poplar Forest Open Balsam Poplar Forest Scrub Cover Types Closed Tall Willow Scrub Closed Tall Alder Scrub Open Tall Willow Scrub Open Tall Alder Scrub Open Sweetgale-Graminoid Scrub Bog Herbaceous Cover Types Elymus Meadow Midgrass-Herb Meadow Hairgrass Meadow Bluejoint Meadow Bluejoint-Herb Meadow Sedge-Shrub Wet Meadow Halophytic Grass Wet Meadow Halophytic Sedge Wet Meadow Mixed Herb Meadow Halophytic Herb Wet Meadow Aquatic Herbaceous Cover Types Aquatic Herbaceous Unvegetated Cover Types Open Water Barren/Unvegetated References Cited... 19

6 Tables Table 1 Vegetation Cover Type Mapping Codes... 4 Table 2 Summary of Cover Types in the Project Area... 5 Table 3 Plant Species Summary for Open Sitka Spruce Forest Cover Type... 6 Table 4 Plant Species Summary for Closed Balsam Poplar Forest Cover Type... 7 Table 5 Plant Species Summary for Open Balsam Poplar Forest Cover Type... 7 Table 6 Plant Species Summary for Closed Tall Willow Scrub Cover Type... 8 Table 7 Plant Species Summary for Closed Tall Alder Scrub Cover Type... 9 Table 8 Plant Species Summary for Open Tall Willow Scrub Cover Type Table 9 Plant Species Summary for Open Tall Alder Scrub Cover Type Table 10 Plant Species Summary for Open Sweetgale-Graminoid Scrub Bog Type Table 11 Plant Species Summary for Elymus Meadow Cover Type Table 12 Plant Species Summary for Midgrass-Herb Meadow Cover Type Table 13 Plant Species Summary for Hairgrass Meadow Cover Type Table 14 Plant Species Summary for Bluejoint Meadow Cover Type Table 15 Plant Species Summary for Bluejoint-Herb Meadow Cover Type Table 16 Plant Species Summary for Sedge-Shrub Wet Meadow Cover Type Table 17 Plant Species Summary for Halophytic Grass Wet Meadow Cover Type Table 18 Plant Species Summary for Halophytic Sedge Wet Meadow Cover Type Table 19 Plant Species Summary for Mixed Herb Meadow Cover Type Table 20 Plant Species Summary for Halophytic Herb Wet Meadow Cover Type Figures Figure 1 Project Vicinity Map... 2 Appendices Appendix A - Plant Species list Appendix B - Representative cover type photographs Appendix C - Vegetation mapping (33 maps)

7 Vegetation Study 1.0 Introduction and Purpose The Alaska Department of Transportation and Public Facilities (DOT&PF), in cooperation with the Federal Highway Administration (FHWA), seeks to make improvements along a 15-mile segment of the Seward Highway, defined herein as the project area. The project area begins at milepost (MP) 75 (near Ingram Creek) and continues north for 15 miles, paralleling the shoreline of Turnagain Arm to the intersection of the Seward and Alyeska Highways near Girdwood at MP 90 (Figure 1). The MP segment is one of the few remaining segments in a series of planned improvements along the length of the Seward Highway between Potter Marsh in south Anchorage and Turnagain Pass (MP 68.5) that aims to extend the service life of the highway and improve safety. Vegetation mapping was completed for the Seward Highway MP Project. Dominant vegetation types were delineated and coded using Level IV of the Alaska Vegetation Classification System (Viereck et al., 1992). Vegetation was delineated for an area extending 250 feet from either side (500 feet total corridor width) of the existing highway centerline (Figure 1). The mapped area encompasses approximately 973 acres. This vegetation mapping will serve as the basis for discussion of potential project related impacts to vegetation and wildlife. The fieldwork for this study was conducted in conjunction with the wetland study during a threeweek period in August and September The study was conducted by biologists on staff at HDR Alaska, Inc. 2.0 Project Environment 2.1 Project Location The proposed project is located at the southern boundary of the Municipality of Anchorage, approximately 30 to 40 miles south of the Anchorage Bowl. The project corridor includes the intersection leading to Girdwood, the Twenty Mile River boat launch area, the Alaska Railroad Portage Station, and the Portage Glacier Road intersection which leads to the Begich-Boggs Visitor Center and the Whittier Tunnel. The highway is heavily used by truck, bus, recreational vehicle, and trailer traffic. The Seward Highway is the only road connection between the Kenai Peninsula and the rest of the state and also provides the sole surface connection to Girdwood and Whittier. 2.2 Climate The climate of the project area can be described as Humid Temperate, with both maritime and continental influences (DeVelice et al. 1999). The Western Regional Climate Center (WRRC) maintains a weather station at Girdwood, Alaska, in close proximity to the project area. Data recorded at this station for the past thirty years gives an average annual maximum temperature of 36.0 F and an average annual minimum temperature of 24.2 F (WRCC 2007). The normal temperature range for this area is 68 F to 10 F, summer to winter. Mean annual precipitation at the Girdwood station is inches, with September as the highest rainfall month (6.72 inches); and mean annual snowfall is inches (WRRC 2007). Seward Highway MP AKDOT&PF March 2008

8 Vegetation Study Precipitation in the region varies considerably with altitude. The Upper Turnagain Landscape Assessment (UTLA) (USFS 2004) notes that, in the general project area, normal precipitation in valleys is 20 inches, while alpine areas receive 90 inches. Normal snowfall is 20 inches and 100 inches, respectively. Figure 1 Project Vicinity Map 2.3 Geography and Geology The project area lies within a region referred to as the Upper Turnagain area, bounded by the Chugach Mountains to the north, Prince William Sound to the east, Turnagain Arm to the west, and the Kenai Mountains to the south. The Upper Turnagain Area is part of the Valdez Group (USFS 2004). Bedrock is dominated by undifferentiated sedimentary rock, consisting of graywacke, shale, slate, and conglomerates. Frost-shattered rocks in high alpine areas, colluvium and glacial drift on side slopes, and alluvium and glacially deposited materials on valley floors overly the bedrock. The physical landscape consists of high relief coastal and mountainous terrain. Glaciers have carved U-shaped valleys, surrounded by steep and rocky side slopes, in the Turnagain Arm area (DeVelice et al. 1999). Large glaciers still exist in the upper portions of area watersheds (USFS 2004). Area watersheds drain into the upper portion of Turnagain Arm. Seward Highway MP AKDOT&PF March 2008

9 Vegetation Study 2.4 Vegetation The UTLA identifies the project area as the Turnagain Arm Ecological Subsection (USFS 2004). This Subsection applies to the lowlands and sideslopes adjacent to Turnagain Arm, including the broad outwash plains. The Subsection is bounded by steep, rocky, glaciated sideslopes. Two dominant vegetation types are expected in alpine areas and on mountain sideslopes: dwarf scrublands and herbaceous vegetation. On the remaining sideslopes and in valley bottoms, the expected dominant vegetation types are mixed needleleaf and broadleaf forests. Much of the landscape is relatively undisturbed by human activities (USFS 2004), leaving climate, landform, and natural processes (e.g. glaciation, avalanches, and wildfires) as the primary factors influencing plant community cover types. 3.0 Methods HDR scientists conducted the fieldwork for this study over a three-week period between August 30 and September 19, Prior to fieldwork, locations of characteristic plant communities occurring at different landform positions, representative wetland or upland sites (based on aerial photography interpretation), as well as questionable areas were selected using a Geographic Information System (GIS). These selected field sampling locations were uploaded into handheld global positioning system (GPS) units. Once in the field, scientists used the waypoints in the GPS unit to navigate to areas needing investigation. Locations were studied using the USACOE 1987 wetland delineation manual s three-parameter method of determining an area s wetland status and methods described in the Alaska Interim Regional Supplement to the 1987 Wetland Delineation Manual (USACOE 1987, USACOE 2006). This included collecting detailed information on plant community composition. Upon arrival at a waypoint scientists either completed a standard Corps of Engineers wetland determination form or took detailed notes. Each sites plant community was characterized using the Alaska Vegetation Classification System (Viereck et al. 1992). The codes used are included in Table 1. Standard USACOE wetland determination data forms included in the 2006 Alaska Interim Regional Supplement Manual were completed at 42 sites. Additionally, photographs and observational data were collected at an additional 35 locations to document water bodies and sites that were similar to those where a data form had already been completed. In total, 77 locations were visited. Each location visited was logged into the GPS unit. Final vegetation mapping was completed for the project area primarily by using aerial photography interpretation. Vegetation mapping derived from air photo interpretation was compared to field-collected vegetation data (obtained from wetland delineation field efforts). If the vegetation mapping differed from field-collected data, the mapping was revised to match actual, on the ground conditions. The data was incorporated into a GIS database by digitizing the vegetation type boundaries onto a digital, orthorectified aerial photograph. Seward Highway MP AKDOT&PF March 2008

10 Vegetation Study Table 1 Vegetation Cover Type Mapping Codes Mapping Code Description Level I Level II Level III Level IV IA2a IB1c IB2c IIB1a IIB1b IIB2a IIB2b IIC2j Open Sitka Spruce Forest Closed Balsam Poplar Forest Open Balsam Poplar Forest Closed Tall Willow Scrub Closed Tall Alder Scrub Open Tall Willow Scrub Open Tall Alder Scrub Open Sweetgale- Graminoid Scrub Bog Forest Needleleaf Open (25-60% canopy) Forest Broadleaf Closed (60-100% canopy) Forest Broadleaf Open (25-60% canopy) Scrub Tall Scrub Closed (75-100% canopy) Scrub Tall Scrub Closed (75-100% canopy) Scrub Tall Scrub Open (25-75% canopy) Scrub Tall Scrub Open (25-75% canopy) Scrub Low Scrub Open (25-75% canopy) Sitka spruce Balsam poplar Balsam poplar Willow Alder Willow Alder IIIA1a Elymus Meadow Herbaceous Graminoid Dry Elymus IIIA1d Midgrass-Herb Meadow Sweetgale-graminoid Bog Herbaceous Graminoid Dry Midgrass-herb IIIA1e Hair Grass Meadow Herbaceous Graminoid Dry Hair-grass IIIA2a Bluejoint Meadow Herbaceous Graminoid Mesic Bluejoint meadow IIIA2b IIIA3g IIIA3h IIIA3i IIIB2a IIIB3d IIID1x IIID2x Water Barren Bluejoint-Herb Meadow Sedge-Shrub Wet Meadow Halophytic Grass Wet Meadow Halophytic Sedge Wet Meadow Mixed Herbs Meadow Halophytic Herb Wet Meadow Freshwater Aquatic Herbaceous Brackish Water Aquatic Herbaceous Herbaceous Graminoid Mesic Bluejoint-herb Herbaceous Graminoid Wet Subarctic lowland sedge-shrub wet meadow Herbaceous Graminoid Wet Halophytic grass wet meadow Herbaceous Graminoid Wet Halophytic sedge wet meadow Herbaceous Forb Mesic Mixed herbs Herbaceous Forb Wet Halophytic herb wet meadow Herbaceous Aquatic Freshwater Not identified Herbaceous Aquatic Brackish Water Not identified Open water - No Viereck classification code available Barren/unvegetated - No Viereck classification code available Seward Highway MP AKDOT&PF March 2008

11 Vegetation Study 4.0 Results and Discussion A total of 22 cover types, including 18 terrestrial, 2 aquatic, and 2 unvegetated types were identified in the 973-acre project area (Table 2). Twenty of these types match classes described in The Alaska Vegetation Classification (Viereck et al. 1992). HDR staff identified 110 separate plant species in the project area. A complete list of these species is included in Appendix A. In conjunction with the wetland study, cover estimates for plant species were completed at 42 sites. A breakdown of the number of wetland data forms collected at each vegetation cover type is included in Table 3. No data forms were completed in areas of open water (i.e., ponds, lakes, or streams), a single form was completed in a barren silt channel, and no forms were completed within any other unvegetated area. Wetland data forms are included in the Seward Highway MP Preliminary Jurisdictional Determination (HDR 2008). Table 2 Summary of Cover Types in the Project Area Vegetation Community Type Data Form ID #s Acres % Area Total Sites IA2a. Open Sitka Spruce Forest 130, 133, % 3 IB1c. Closed Balsam Poplar Forest % 1 IB2c. Open Balsam Poplar Forest % 1 IIB1a. Closed Tall Willow Scrub 110, % 2 IIB1b. Closed Tall Alder Scrub 101, 107, 111, 118, 123, 200, 213, % 8 IIB2a. Open Tall Willow Scrub 102, 202, 207, % 4 IIB2b. Open Tall Alder Scrub % 1 IIC2j. Open Sweetgale-Graminoid Scrub Bog 106, 226, % 3 IIIA1a. Elymus Meadow % 1 IIIA1d. Midgrass-Herb Meadow 215, 238, % 3 IIIA1e. Hair Grass Meadow % 1 IIIA2a. Bluejoint Meadow % 1 IIIA2b. Bluejoint-Herb Meadow 100, 120, 121, 222, % 5 IIIA3g. Sedge-Shrub Wet Meadow % - IIIA3h. Halophytic Grass Wet Meadow 135, % 2 IIIA3i. Halophytic Sedge Wet Meadow % 1 IIIB2a. Mixed Herbs Meadow 204, % 2 IIIB3d. Halophytic Herb Wet Meadow 124, % 2 IIID1x. Freshwater Aquatic Herbaceous % - IIID2x. Brackish Water Aquatic Herbaceous % - Open Water % - Barren/Unvegetated % 1 Total Cover types found in the project area are described below according to Viereck et al and Plant Community Types of the Chugach National Forest: south-central Alaska (DeVelice et al. 1999). Mapped types are divided into 5 categories for discussion. These categories are: forest, shrub, herbaceous, aquatic herbaceous, and unvegetated cover types. Photographs representative of each cover type are included in Appendix B. Figures showing the cover types mapped in the project area, overlaid on aerial photographs, are included in Appendix C, Figures 1 through 33. Seward Highway MP AKDOT&PF March 2008

12 Vegetation Study 4.1 Forest Cover Types Open Sitka Spruce Forest Within the project area, open Sitka spruce forest covers approximately 28.3 acres (2.9 percent of the mapped area) (Table 2). This cover type is most abundant along the steep mountain side slopes located east of the Seward Highway and Alaska Railroad in northern half of the project area, between Twentymile River and Girdwood Valley. General characteristics of this forest type include a dense overstory (35 to 55 percent cover) dominated by Sitka spruce with mixed mountain hemlock. The understory community is dominated by Sitka alder, devil s club, oval-leaf blueberry, strawberry-leaf raspberry, bunchberry dogwood, clasp-leaf twisted-stalk, and three-leaf foamflower. A complete list of plant species found within this cover type is included in Table 3. The Alaska Vegetation Classification System code for this community type is IA2a. Three data forms were completed for this cover type (data form ID numbers 130, 133, and 225). Representative photographs of this cover type are included in Appendix B, photographs 1 and 2. Table 3 Plant Species Summary for Open Sitka Spruce Forest Cover Type Sitka alder (Alnus sinuata) Kenai birch (Betula kenaica) Northern groundcone (Boschniakia rossica) Bunchberry dogwood (Cornus canadensis) Mountain woodfern (Dryopteris dilatata) Tall fireweed (Epilobium angustifolium) Sweet-scent bedstraw (Galium triflorum) Oak fern (Gymnocarpium dryopteris) Alpine heuchera (Heuchera glabra) Stiff clubmoss (Lycopodium annotinum) False azalea (Menziesia ferruginea) Single delight (Moneses uniflora) Devil's club (Oplopanax horridus) Sitka spruce (Picea sitchensis) Common red raspberry (Rubus idaeus) Strawberry-leaf raspberry (Rubus pedatus) European red elder (Sambucus racemosa) Three-leaf foamflower (Tiarella trifoliata) Mountain hemlock (Tsuga mertensiana) Oval-leaf blueberry (Vaccinium ovalifolium) Closed Balsam Poplar Forest Closed balsam poplar forests are scattered throughout the project area, typically occurring only in small isolated stands. Overall, this cover type was identified across approximately 7.6 acres, less than one percent of the mapped area (Table 2). This forest type is most common alongside developed areas between Girdwood and Portage, generally mapped as narrow linear bands situated northeast of the existing highway alignment and along the edges of several other small roads. General characteristics of closed balsam poplar forest include a dense canopy of balsam poplar (60 to 100 percent cover) with a varied understory influenced by the density of canopy cover. Shrub species, commonly alder and willow, decrease in density as balsam poplar stands mature and form a closed canopy (DeVelice 1999). Devil s club and high-bush cranberry are also common shrubs in this cover type. Common herbaceous plants include fireweed, clasp-leaf twisted-stalk, goastsbeard, woodfern, field horsetail, and bluejoint reedgrass (Table 4). Seward Highway MP AKDOT&PF March 2008

13 Vegetation Study The Alaska Vegetation Classification System code for this community type is IB1c. One data form was completed for this cover type (data form ID number 122). Representative photographs of this cover type are included in Appendix B, photographs 3 and 4. Table 4 Plant Species Summary for Closed Balsam Poplar Forest Cover Type Baneberry (Actaea rubra) Goatsbeard (Aruncus sylvester) Bluejoint reedgrass (Calamagrostis canadensis) Mountain woodfern (Dryopteris dilatata) Field horsetail (Equisetum arvense) Large-leaf avens (Geum macrophyllum) Cow-parsnip (Heracleum lanatum) Devil s club (Oplopanax horridus) Balsam poplar (Populus balsamifera) Clasp-leaf twisted-stalk (Streptopus amplexifolius) High-bush cranberry (Viburnum edule) Open Balsam Poplar Forest Open balsam poplar forests cover approximately 41 acres, or 4.2 percent of the mapped project area (Table 2). Similar to the closed balsam poplar forest type, this cover type also borders developed and disturbed, occurring mostly alongside the Highway and minor roadways, the railroad right-of-way, areas adjacent to drainages, and in transition zones between the needleleaf forest and scrub types. General characteristics of this cover type include an open canopy (25 to 60 percent cover) of balsam poplar (in the project area, the subspecies black cottonwood was observed) with Sitka alder dominating the tall shrub stratum. Common herbaceous species include yarrow, lady fern, and bluejoint reedgrass (Table 5). The Alaska Vegetation Classification System code for this community type is IB2c. One data form was completed for this cover type (data form ID number 212). Representative photographs of this cover type are included in Appendix B, photographs 5 and 6. Table 5 Plant Species Summary for Open Balsam Poplar Forest Cover Type Common yarrow (Achillea millefolium) Sitka alder (Alnus sinuata) Seawatch angelica (Angelica lucida) Alpine lady fern (Athyrium filix-femina) Bluejoint reedgrass (Calamagrostis canadensis) Small bedstraw (Galium trifidum) Sitka spruce (Picea sitchensis) Black cottonwood (Populus balsamifera trichocarpa) European red elder (Sambucus racemosa) 4.2 Scrub Cover Types Closed Tall Willow Scrub Closed tall willow scrub is a common and widespread cover type throughout the low-lying coastal areas of the project area. This cover type was mapped across 44 acres, or 4.5 percent of the project area (Table 2). General characteristics of this cover type include a dense overstory of tall (1.5 meters (5 feet) or taller) shrubs, dominated by willows. In general, total shrub cover is 75 percent or greater, with the dominant species including felt-leaf willow, Barclay s willow, or Sitka willow. Alder and Seward Highway MP AKDOT&PF March 2008

14 Vegetation Study balsam poplar were also present in the shrub canopy, often growing taller than the surrounding willow thicket. Understory species varied considerably by site and canopy cover, but is generally dominated by herbaceous plants (Table 6). The most common understory plants include bluejoint reedgrass and field horsetail. The Alaska Vegetation Classification System code for this community type is IIB1a. Two data forms were completed for this cover type (data form ID numbers 110 and 113). Representative photographs of this cover type are included in Appendix B, photographs 7 and 8. Table 6 Plant Species Summary for Closed Tall Willow Scrub Cover Type Common Yarrow (Achillea millefolium) Green alder (Alnus crispa) Sitka alder (Alnus sinuata) Thin-leaf alder (Alnus tenuifolia) Kneeling Angelica (Angelica genuflexa) Seawatch angelica (Angelica lucida) Goatsbeard (Aruncus sylvester) Alpine lady fern (Athyrium filix-femina) Bluejoint reedgrass (Calamagrostis canadensis) Merten's sedge (Carex mertensii) Hemlock-parsley (Conioselinum chinense) Tufted hairgrass (Deschampsia beringensis) Sea lyme-grass (Elymus arenarius) Tall fireweed (Epilobium angustifolium) Field horsetail (Equisetum arvense) Variegated horsetail (Equisetum variegatum) Sweet-scent bedstraw (Galium triflorum) Large-leaf avens (Geum macrophyllum) Cow-parsnip (Heracleum lanatum) Smooth alumroot (Heuchera glabra) Meadow barley (Hordeum brachyantherum) Vetchling peavine (Lathyrus palustris) Scotch lovage (Ligusticum scothicum) Sweetgale (Myrica gale) Balsam poplar (Populus balsamifera) Marsh cinquefoil (Potentilla palustris) Arctic raspberry (Rubus arcticus) Felt-leaf willow (Salix alaxensis) Barclay willow (Salix barclayi) Under-green willow (Salix commutata) Hooker's willow (Salix hookeriana) Sitka willow (Salix sitchensis) European red elder (Sambucus racemosa) Sitka burnet (Sanguisorba stipulata) Few-flower meadow-rue (Thalictrum sparsiflorum) European starflower (Trientalis europaea) Closed Tall Alder Scrub Closed tall alder scrub is common across a variety of landforms within the project area, including steep slopes, avalanche paths, and floodplains and along drainages, forest edges, and streambanks. Throughout southcentral Alaska, green alder is commonly the dominant species in low-lying areas and floodplain sites, while Sitka alder commonly dominates mountain slopes and avalanche paths (DeVelice 1999). This cover type occurs across approximately 59.5 acres, or 6.1 percent of the mapped project area (Table 2). Closed lader scrub is dominated by a dense canopy (75 percent or greater) of alder with mixed willow and balsam poplar. Two slightly different types of this community were observed in the project area, including a Sitka alder/field horsetail community and a Sitka alder/willow community. The Sitka alder/field horsetail was the most common type observed in the project area. General characteristics of this cover type include a dense canopy of Sitka alder with field horsetail dominating the undergrowth. This cover type is most common along streambanks and across the low-lying coastal flats of the project area. Seward Highway MP AKDOT&PF March 2008

15 Vegetation Study Sitka alder/willow was the second type observed in the project area. Sitka alder and both Barclay s and felt-leaf willow dominate the tall shrub layer. A minor cover of white spruce and black cottonwood is also scattered throughout the dense overstory. The herbaceous layer is generally sparse and varies in composition (Table 7). This type is most common across steep slopes, rock outcrops, and within avalanche paths. The Alaska Vegetation Classification System code for this community type is IIB1b. Eight data forms were completed for this cover type (data form ID numbers 101, 107, 111, 118, 123, 200, 213, and 233). Representative photographs of this cover type are included in Appendix B, photographs 9 and 10. Table 7 Plant Species Summary for Closed Tall Alder Scrub Cover Type Green alder (Alnus crispa) Sitka alder (Alnus sinuata) Kneeling Angelica (Angelica genuflexa) Seawatch angelica (Angelica lucida) Wormwood (Artemisia tilesii) Alpine lady fern (Athyrium filix-femina) Bluejoint reedgrass (Calamagrostis canadensis) Hemlock-parsley (Conioselinum chinense) Bunchberry (Cornus canadensis) Field horsetail (Equisetum arvense) Water horsetail (Equisetum fluviatile) Small bedstraw (Galium trifidium) Cow-parsnip (Heracleum lanatum) Devil s club (Oplopanax horridus) White spruce (Picea glauca) Balsam poplar (Populus balsamifera) Silverweed (Potentilla anserina) Felt-leaf willow (Salix alaxensis) Barclay willow (Salix barclayi) European red elder (Sambucus racemosa) Sitka burnet (Sanguisorba sitchensis) Sitka burnet (Sanguisorba stipulata) Sitka starwort (Stellaria sitchana) Common dandelion (Taraxacum officinale) Open Tall Willow Scrub Open tall willow scrub is the second most abundant vegetated cover type in the project area, covering approximately 92.9 acres, or 9.6 percent of the project area (Table 2). This cover type is most common across the broad flat coastal floodplain areas and outwash deposits located at the mouths of Twentymile, Portage, and Placer Valleys. General characteristics of this cover type include an open canopy (25 to 75 percent cover) dominated by a mix of willow species. Common co-dominant species seen include felt-leaf, Barclay s, and diamond-leaf willow. The understory is comprised of a mix of bluejoint reedgrass and a variety of forb species (Table 8). In wetter environments, including those subject to periodic tidal flooding, Barclay s willow is the dominant overstory with sweetgale, sedges, marsh cinquefoil, and field horsetail comprise the undergrowth. The Alaska Vegetation Classification System code for this community type is IIB2a. Four data forms were completed for this cover type (data form ID numbers 102, 202, 207, and 216). Representative photographs of this cover type are included in Appendix B, photographs 11 and 12. Seward Highway MP AKDOT&PF March 2008

16 Vegetation Study Table 8 Plant Species Summary for Open Tall Willow Scrub Cover Type Common Yarrow (Achillea millefolium) Green alder (Alnus crispa) Sitka alder (Alnus sinuata) Kneeling Angelica (Angelica genuflexa) Seawatch angelica (Angelica lucida) Bluejoint reedgrass (Calamagrostis canadensis) Sea lyme-grass (Elymus arenarius) Water horsetail (Equisetum fluviatile) Small bedstraw (Galium trifidum) Meadow barley (Hordeum brachyantherum) Vetchling peavine (Lathyrus palustris) Nootka lupine (Lupinus nootkatensis) Sweetgale (Myrica gale) Northern grass-of-parnassus (Parnassia palustris) Fowl bluegrass (Poa palustris) Silverweed (Potentilla anserina) Pink wintergreen (Pyrola asarifolia) Macoun's butter-cup (Ranunculus macounii) Felt-leaf willow (Salix alaxensis) Barclay willow (Salix barclayi) Under-green willow (Salix commutata) Hooker's willow (Salix hookeriana) Diamond-leaf willow (Salix planifolia) Sitka willow (Salix sitchensis) Sitka burnet (Sanguisorba sitchensis) European starflower (Trientalis europaea) Open Tall Alder Scrub Few areas of open tall alder scrub occur within the project area, covering approximately 13.4 acres, or 1.4 percent of the project area (Table 2). This cover type was observed across several small areas adjacent to disturbed road and railroad corridors as well as within small scattered patches across the coastal flats of Upper Turnagain Arm. General characteristics of this cover type is include an open canopy (25 to 75 percent cover) dominated by alder. White spruce and balsam poplar trees are often scattered across this cover type, overtopping the denser alder canopy. Common understory species include devil s club, European red elder, mountain woodfern, clasp-leaf twisted-stalk, and lady fern (Table 9). The Alaska Vegetation Classification System code for this community type is IIB2b. One data form was completed for this cover type (data form ID number 126). Representative photographs of this cover type are included in Appendix B, photographs 13 and 14. Table 9 Plant Species Summary for Open Tall Alder Scrub Cover Type Baneberry (Actaea rubra) Green alder (Alnus crispa) Lyre-leaf rockcress (Arabis lyrata) Goatsbeard (Aruncus sylvester) Alpine lady fern (Athyrium filix-femina) Mountain woodfern (Dryopteris dilatata) Sweet-scent bedstraw (Galium triflorum) Cow-parsnip (Heracleum lanatum) Devil s club (Oplopanax horridus) White spruce (Picea glauca) Balsam poplar (Populus balsamifera) Sitka willow (Salix sitchensis) European red elder (Sambucus racemosa) Clasp-leaf twisted-stalk (Streptopus amplexifolius) Open Sweetgale-Graminoid Scrub Bog Approximately 30.3 acres (3.1 percent of the mapped area) of sweetgale-graminoid scrub bogs were mapped in the project area (Table 2). This cover type is most abundant across low-lying wetland areas that are periodically flooded. Several widespread areas of this bog cover type are located along the coastal flats between Ingram Creek and Placer River, at the mouth of Girdwood Valley, and within a tidally influenced area situated between the highway and railroad west of Seward Highway MP AKDOT&PF March 2008

17 Vegetation Study Twentymile River. All of these areas have generally flat topography with the majority of the plant growth occurring on low hummocks surrounded by surface water. General characteristics of this cover type include a low scrub community dominated by sweetgale and interspersed with mixed willow and swamp birch. The herbaceous stratum is generally dominated by Lyngbye s sedge and marsh cinquefoil with a variety of other graminoid and forb species (Table 10). The Alaska Vegetation Classification System code for this community type is IIC2j. Three data forms were completed for this cover type (data form ID numbers 106, 226, and 239). Representative photographs of this cover type are included in Appendix B, photographs 15 and 16. Table 10 Plant Species Summary for Open Sweetgale-Graminoid Scrub Bog Type Bluejoint reedgrass (Calamagrostis canadensis) Sitka alder (Alnus sinuata) Kenai birch (Betula kenaica) Swamp birch (Betula nana) Paper birch (Betula papyrifera) Bluejoint reedgrass (Calamagrostis canadensis) Lyngbye's sedge (Carex lyngbyei) Western water-hemlock (Cicuta douglasii) Pale bastard toadflax (Comandra pallida) Tufted hairgrass (Deschampsia cespitosa) Marsh willow-herb (Epilobium palustre) Field horsetail (Equisetum arvense) Sweet-scent bedstraw (Galium triflorum) Buckbean (Menyanthes trifoliata) Sweetgale (Myrica gale) Sitka spruce (Picea sitchensis) Marsh cinquefoil (Potentilla palustris) Arctic raspberry (Rubus arcticus) Western dock (Rumex fenestratus) Barclay willow (Salix barclayi) Bebb willow (Salix bebbiana) Under-green willow (Salix commutata) Hooker's willow (Salix hookeriana) 4.3 Herbaceous Cover Types Elymus Meadow Open meadow communities dominated by sea lyme-grass cover approximately 13.4 acres, or 1.4 percent of the project area (Table 2). This cover type is characteristic of coastal and near-coastal shorelines and the upper parts of intertidal beaches; it is also found on floodplains, gently sloping hills, and estuaries. Sea lyme-grass is often the first species to colonize shifting sand dunes and gravel bars along the coast. As the substrate stabilizes, grasses, sedges, forbs, or low shrubs invade the meadow community (DeVelice 1999). Sea lyme-grass dominates this community type, often growing in dense, pure stands. Although no other species are consistent in this community type, sea lyme-grass often mixes with other grasses and forbs, including vetchling peavine, Scotch lovage, and Poa grass species (Table 11). Woody plants are scarce or absent in most sea lyme-grass meadows. The Alaska Vegetation Classification System code for this community type is IIIA1a. One data form was completed for this cover type (data form ID number 219). Representative photographs of this cover type are included in Appendix B, photographs 17 and 18. Seward Highway MP AKDOT&PF March 2008

18 Vegetation Study Table 11 Plant Species Summary for Elymus Meadow Cover Type Common Yarrow (Achillea millefolium) Seawatch angelica (Angelica lucida) Annual hawksbeard (Crepis tectorum) Sea lyme-grass (Elymus arenarius) Field horsetail (Equisetum arvense) Vetchling peavine (Lathyrus palustris) Scotch lovage (Ligusticum scothicum) Nootka lupine (Lupinus nootkatensis) Fowl bluegrass (Poa palustris) Kentucky bluegrass (Poa pratensis) Common dandelion (Taraxacum officinale) Midgrass-Herb Meadow The midgrass-herb meadow type covers approximately 12.1 acres, or 1.2 percent of the mapped area (Table 2). This cover type is scattered throughout the project area generally occurring in disturbed areas adjacent to the highway and railroad embankments. This cover type is dominated by a dense cover of grasses and broad-leaved forbs (Table 12). Common dominant grasses include tufted hairgrass, meadow barley, and seaside plantain. Codominant herbs include beach pea, sea lyme-grass, and common yarrow (Table 12). Willows may be scattered throughout the community but are generally scarce or absent. The Alaska Vegetation Classification System code for this community type is IIIA1d. Three data forms were completed for this cover type (data form ID numbers 215, 238, and 241). Representative photographs of this cover type are included in Appendix B, photographs 19 and 20. Table 12 Plant Species Summary for Midgrass-Herb Meadow Cover Type Common Yarrow (Achillea millefolium) Sitka alder (Alnus sinuata) Lyngbye s sedge (Carex lyngbyei) Tufted hairgrass (Deschampsia cespitosa) Sea lyme-grass (Elymus arenarius) Meadow barley (Hordeum brachyantherum) Beach pea (Lathyrus maritimus) Scotch lovage (Ligusticum scothicum) Sweetgale (Myrica gale) Northern grass-of-parnassus (Parnassia palustris) White spruce (Picea glauca) Seaside plantain (Plantago maritima) Barclay willow (Salix barclayi) Bebb willow (Salix bebbiana) Hooker s willow (Salix hookeriana) White clover (Trifolium repens) Hairgrass Meadow Open meadows dominated by hairgrass cover approximately 5.2 acres, less than one percent of the project area (Table 2). This cover type was scattered throughout areas in the northern portion of the project area (north of Portage Creek). In general, mapped hairgrass meadows are limited to disturbed areas directly adjacent the highway or railroad corridors. Many of the mapped areas occur as narrow, linear features paralleling the disturbed or barren corridors. General characteristics of this cover type include an open graminoid meadow dominated by tufted hairgrass. Other plant growth in this cover type is usually diverse, with small cover percentages of many other species. Other common species may include sea lyme-grass, Pacific silverweed, and seaside plantain (Table 13). Seward Highway MP AKDOT&PF March 2008

19 Vegetation Study The Alaska Vegetation Classification System code for this community type is IIIA1e. One data forms were completed for this cover type (data form ID number 210). Representative photographs of this cover type are included in Appendix B, photographs 21 and 22. Table 13 Plant Species Summary for Hairgrass Meadow Cover Type Lyngbye's sedge (Carex lyngbyei) Tufted hairgrass (Deschampsia beringensis) Sea lyme-grass (Elymus arenarius) Arctic rush (Juncus arcticus) Vetchling peavine (Lathyrus palustris) Sweetgale (Myrica gale) Northern grass-of-parnassus (Parnassia palustris) Seaside plantain (Plantago maritima) Silverweed (Potentilla anserina) Nootka alkali grass (Puccinellia nutkaensis) Seaside butter-cup (Ranunculus cymbalaria) Seaside arrowgrass (Triglochin maritimum) Bluejoint Meadow Bluejoint meadows cover approximately 8.2 acres, less than one percent of the mapped project area (Table 2). The largest area mapped of this cover type is located along the coastal flats near the mouth of Girdwood Valley. This area is immediately upslope of the upper intertidal zone of Turnagain Arm. Several other small areas of this cover type were identified near Ingram Creek and along the coastal flats between Peterson Creek and Twentymile River. General characteristics of these bluejoint meadows include a dense cover dominated almost exclusively of bluejoint reedgrass. Several other graminoid and forb species may be present but generally occur in low quantities and are scattered throughout. Table 14 lists other species identified in this cover type. The Alaska Vegetation Classification System code for this community type is IIIA2a. One data form was completed for this cover type (data form ID number 227). Representative photographs of this cover type are included in Appendix B, photographs 23 and 24. Table 14 Plant Species Summary for Bluejoint Meadow Cover Type Bluejoint reedgrass (Calamagrostis canadensis) Mud sedge (Carex limosa) Lyngbye's sedge (Carex lyngbyei) Western water-hemlock (Cicuta douglasii) Rough bentgrass (Agrostis scabra) Small bedstraw (Galium trifidum) Marsh cinquefoil (Potentilla palustris) Western dock (Rumex fenestratus) Marsh willow-herb (Epilobium palustre) Bluejoint-Herb Meadow Bluejoint-herb meadows cover approximately 8.4 acres of the project area, less than one percent of the mapped area (Table 2). This cover type is scattered across the project area, occurring in both costal flat areas and on steep mountain slopes east of the Seward Highway. Where situated on steep mountain slopes, this cover type is subject to periodic powerline right-of-way vegetation clearing practices by Chugach Electric Association. Bluejoint-herb meadows typically occupy many of the same landscape positions as bluejoint meadows. Both of these cover types are known to occur on floodplains, upland slopes from valley bottom to tree line, disturbed and undisturbed tidal foot slopes and raised tidal flats, low relief hills, undisturbed, disturbed, and dissected mountain side slopes, along streambanks, and in lowland fens and recently drained lake basins (DeVelice 1999). Seward Highway MP AKDOT&PF March 2008

20 Vegetation Study General characteristics of bluejoint-herb meadows include an open meadow community dominated equally by bluejoint reedgrass and other herb species, commonly including tall fireweed and horsetail species (Table 15). Other mixed shrub and forb species are scattered throughout this meadow community, however, are typically not in great abundance. The Alaska Vegetation Classification System code for this community type is IIIA2b. Five data forms were completed for this cover type (data form ID numbers 100, 120, 121, 222, and 235). Representative photographs of this cover type are included in Appendix B, photographs 25 and 26. Table 15 Plant Species Summary for Bluejoint-Herb Meadow Cover Type Green alder (Alnus crispa) Sitka alder (Alnus sinuata) Kneeling Angelica (Angelica genuflexa) Angelica sp Goatsbeard (Aruncus sylvester) Alpine lady fern (Athyrium filix-femina) Bluejoint reedgrass (Calamagrostis canadensis) Water sedge (Carex aquatilis) Lyngbye s sedge (Carex lyngbyei) Hemlock-parsley (Conioselinum chinense) Tufted hairgrass (Deschampsia cespitosa) Mountain woodfern (Dryopteris dilatata) Tall fireweed (Epilobium angustifolium) Marsh willow-herb (Epilobium palustre) Field horsetail (Equisetum arvense) Meadow horsetail (Equisetum pratense) Red fescue (Festuca rubra) Northern bedstraw (Galium boreale) Sweet-scent bedstraw (Galium triflorum) Large-leaf avens (Geum macrophyllum) Cow-parsnip (Heracleum lanatum) Beach pea (Lathyrus maritimus) Devil s club (Oplopanax horridus) Sitka spruce (Picea sitchensis) Large-flower bluegrass (Poa eminens) Marsh cinquefoil (Potentilla palustris) White water butter-cup (Ranunculus aquatilis) Common red raspberry (Rubus idaeus) Barclay willow (Salix barclayi) Sitka willow (Salix sitchensis) European red elder (Sambucus racemosa) Greene s mountain-ash (Sorbus scopulina) Northern burreed (Sparganium hyperboreum) Common dandelion (Taraxacum officinale) Few-flower meadow-rue (Thalictrum sparsiflorum) Narrow beech fern (Thelypteris phegopteris) European starflower (Trientalis europaea) Sedge-Shrub Wet Meadow Approximately 19.6 acres (2 percent of the mapped area) of sedge-shrub wet meadow were identified in the project area (Table 2). This cover type was mapped across low-lying wetland areas situated along the coastal flats of Upper Turnagain Arm. Surface water is common throughout this cover type. General characteristics of sedge-shrub meadows include a dense cover of Lyngbye s sedge mixed with sweetgale and low willow. Scattered throughout the community are assorted forbs including horsetail, vetchling peavine, Pacific silverweed, and marsh cinquefoil (Table 16). The Alaska Vegetation Classification System code for this community type is IIIA3g. No data forms were completed for this cover type. Representative photographs of this cover type are included in Appendix C, photographs 27 and 28. Seward Highway MP AKDOT&PF March 2008

21 Vegetation Study Table 16 Plant Species Summary for Sedge-Shrub Wet Meadow Cover Type Bluejoint reedgrass (Calamagrostis canadensis) Lyngbye's sedge (Carex lyngbyei) Water horsetail (Equisetum fluviatile) Vetchling peavine (Lathyrus palustris) Sweetgale (Myrica gale) Silverweed (Potentilla anserina) Marsh cinquefoil (Potentilla palustris) Barclay willow (Salix barclayi) Hooker's willow (Salix hookeriana) Halophytic Grass Wet Meadow Halophytic grass wet meadows were mapped across approximately 10.4 acres, or one percent of the project area (Table 2). This cover type was observed throughout the entire project area, generally located along the coastal side of the Seward Highway. Scattered areas of this type were often located within large low-lying wetlands that are subject to seasonal flooding by extreme high tides. General characteristics of halophytic grass wet meadows include dense cover of mixed salttolerant grasses and forbs (Table 17). Common species in nootka alkali grass, seaside plantain, sea lyme-grass, and tufted hairgrass. Some woody species such as Sitka spruce saplings and Barclay s willow were observed, however these were generally scarce or absent within most mapped areas. The Alaska Vegetation Classification System code for this community type is IIIA3h. Two data forms were completed for this cover type (data form ID numbers 135 and 230). Representative photographs of this cover type are included in Appendix B, photographs 29 and 30. Table 17 Plant Species Summary for Halophytic Grass Wet Meadow Cover Type Common Yarrow (Achillea millefolium) Rough bentgrass (Agrostis scabra) Sitka alder (Alnus sinuata) Kneeling Angelica (Angelica genuflexa) Seawatch angelica (Angelica lucida) Lyngbye s sedge (Carex lyngbyei) Hemlock-parsley (Conioselinum chinense) Tufted hairgrass (Deschampsia beringensis) Tufted hairgrass (Deschampsia cespitosa) Sea lyme-grass (Elymus arenarius) Field horsetail (Equisetum arvense) Red fescue (Festuca rubra) Small bedstraw (Galium trifidum) Meadow barley (Hordeum brachyantherum) Thread rush (Juncus filiformis) Vetchling peavine (Lathyrus palustris) Scotch lovage (Ligusticum scothicum) Marsh felwort (Lomatogonium rotatum) Nootka lupine (Lupinus nootkatensis) Sweetgale (Myrica gale) Northern grass-of-parnassus (Parnassia palustris) Sitka spruce (Picea sitchensis) Seaside plantain (Plantago maritima) Leafy white orchid (Platanthera dilatata) Large-flower bluegrass (Poa eminens) Fowl bluegrass (Poa palustris) Nootka alkali grass (Puccinellia nutkaensis) Seaside butter-cup (Ranunculus cymbalaria) Yellow rattle (Rhinanthus minor) Barclay willow (Salix barclayi) Sitka burnet (Sanguisorba sitchensis) Common dandelion (Taraxacum officinale) Seward Highway MP AKDOT&PF March 2008

22 Vegetation Study Halophytic Sedge Wet Meadow Halophytic sedge wet meadows are on of the most dominant vegetated cover type in the project area, covering approximately 97.5 acres, or 10 percent of the mapped area (Table 2). This wet meadow type is common across the broad flat, low-lying wetlands located at the mouths of Girdwood, Twentymile, Portage, and Placer Valleys. Many areas of this cover type on the coastal side of the Seward Highway are subject to periodic tidal flooding. General characteristics of this cover type include a dense cover dominated by Lyngbye s sedge. Other mixed species are present, however, are generally less-abundant and scattered throughout (Table 18). Open water is common throughout this cover type. The Alaska Vegetation Classification System code for this community type is IIIA3i. One data form was completed for this cover type (data form ID number 125). Representative photographs of this cover type are included in Appendix B, photographs 31 through 32. Table 18 Plant Species Summary for Halophytic Sedge Wet Meadow Cover Type Bluejoint reedgrass (Calamagrostis canadensis) Lyngbye's sedge (Carex lyngbyei) Mackenzie water-hemlock (Cicuta mackenziana) Tufted hairgrass (Deschampsia cespitosa) Meadow barley (Hordeum brachyantherum) Vetchling peavine (Lathyrus palustris) Northern grass-of-parnassus (Parnassia palustris) Large-flower bluegrass (Poa eminens) Mixed Herb Meadow Mixed herb meadows are common across the coastal terraces and coastal floodplains located near the mouths of Twentymile and Placer River Valleys. This meadow type covers approximately 52.3 acres, or 5.5 percent of the project area (Table 2). General characteristics of this cover type include a diverse community of mixed grasses and forbs. Common species include lupine, vetchling peavine, silverweed, tufted hairgrass, and sea lyme-grass (Table 19). Some areas may be exposed to seasonal flooding during high tide events, which may limit growth to only the salt tolerant species. Single and small groupings of willows are often scattered throughout this cover type. The Alaska Vegetation Classification System code for this community type is IIIB2a. Two data forms were completed for this cover type (data form ID numbers 124 and 205). Representative photographs of this cover type are included in Appendix B, photographs 33 through 34. Seward Highway MP AKDOT&PF March 2008

23 Vegetation Study Table 19 Plant Species Summary for Mixed Herb Meadow Cover Type Common Yarrow (Achillea millefolium) Seawatch angelica (Angelica lucida) Bluejoint reedgrass (Calamagrostis canadensis) Tufted hairgrass (Deschampsia beringensis) Sea lyme-grass (Elymus arenarius) Field horsetail (Equisetum arvense) Meadow barley (Hordeum brachyantherum) Vetchling peavine (Lathyrus palustris) Scotch lovage (Ligusticum scothicum) Nootka lupine (Lupinus nootkatensis) White sweetclover (Melilotus alba) Northern grass-of-parnassus (Parnassia palustris) White spruce (Picea glauca) Seaside plantain (Plantago maritima) Silverweed (Potentilla anserina) Marsh cinquefoil (Potentilla palustris) Yellow rattle (Rhinanthus minor) Barclay willow (Salix barclayi) Under-green willow (Salix commutata) Hooker's willow (Salix hookeriana) Common dandelion (Taraxacum officinale) White clover (Trifolium repens) Halophytic Herb Wet Meadow Only a few small areas of halophytic herb wet meadow were identified in the project area. These areas are located along the coastline west of the Seward Highway near the mouth of Twentymile River Valley. Overall, approximately 3.2 acres, less than one percent of the project area, were mapped in the project area (Table 2). General characteristics of this cover type include a diverse mix of forb and graminoid species with few willows scattered throughout (Table 20). In the project area, this cover type is exposed to short-term periodic flooding at extreme high tide events. The extent and duration of the tidal waters may play a role in the overall plant species abundance and diversity. The Alaska Vegetation Classification System code for this community type is IIIB3d. Two data forms were completed for this cover type (data form ID numbers 124 and 205). Representative photographs of this cover type are included in Appendix B, photographs 35 through 36. Table 20 Plant Species Summary for Halophytic Herb Wet Meadow Cover Type Common Yarrow (Achillea millefolium) Seawatch angelica (Angelica lucida) Sea lyme-grass (Elymus arenarius) Red fescue (Festuca rubra) Meadow barley (Hordeum brachyantherum) Arctic rush (Juncus arcticus) Vetchling peavine (Lathyrus palustris) Scotch lovage (Ligusticum scothicum) Marsh felwort (Lomatogonium rotatum) Nootka lupine (Lupinus nootkatensis) Northern grass-of-parnassus (Parnassia palustris) Fowl bluegrass (Poa palustris) Kentucky bluegrass (Poa pratensis) Nootka alkali grass (Puccinellia nutkaensis) Arctic dock (Rumex arcticus) Barclay willow (Salix barclayi) Common dandelion (Taraxacum officinale) Alsike clover (Trifolium hybridum) 4.4 Aquatic Herbaceous Cover Types Aquatic Herbaceous This cover type includes shallow ponds and lakes were aquatic vegetation grows. Two types of aquatic environments, freshwater and brackish water were identified in the project area. Approximately 55 acres (5.7 percent of the mapped area) this aquatic cover type was mapped in Seward Highway MP AKDOT&PF March 2008

24 Vegetation Study the project area (Table 2). Aquatic plants were not identified to species in the field; therefore these areas were classified to only Level III of the Alaska Vegetation Classification System (Viereck 1992). Freshwater aquatic herbaceous has an Alaska Vegetation Classification System code of IIID1, brackish water aquatic herbaceous has a code of IIID2. No data forms were completed for aquatic herbaceous areas. 4.5 Unvegetated Cover Types Open Water This cover type includes inundated areas that are generally void of vegetation. Approximately 57.7 acres (5.9 percent of the mapped area) were mapped in the project area (Table 2). Mapped areas include streams, ponds, lakes, and subtidal areas of Turnagain Arm. Open water areas do not have an Alaska Vegetation Classification System code, on the attached map set these areas are labeled as Water. No data forms were completed for open water sites Barren/Unvegetated This cover type identifies areas that are unvegetated or sparsely vegetated. In the project area, this cover type includes unvegetated mudflats, roads, railroads, buildings, disturbed fill embankments, and all other cleared or developed areas. Barren/unvegetated areas cover approximately acres (32.1 percent of the mapped area) of the project area (Table 2). Barren/unvegetated areas have do not have an Alaska Vegetation Classification System code, on the attached map set these areas are labeled as Barren. No data forms were completed for these areas. Seward Highway MP AKDOT&PF March 2008

25 Vegetation Study 5.0 References Cited DeVelice, R.L., C.J. Hubbard, K. Boggs, S. Boudreau, M. Potkin, T. Boucher, and C. Wertheim Plant Community Types of the Chugach National Forest: southcentral Alaska. USDA Forest Service, Chugach National Forest, Alaska Region Technical Publication R10-TP-76. Anchorage, AK. HDR Alaska, Inc Preliminary Jurisdictional Determination Seward highway MP Road and Bridge Rehabilitation Project (Project No. BR-BH-NH-OA3-1(35)/58105/ Prepared for The Alaska Department of Transportation & Public Facilities. Anchorage, AK. U.S. Army Corps of Engineers Alaska Interim Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Alaska Region, J.S. Wakeley, R.W. Lichvar, and C.V. Noble, eds. ERDC/EL TR U.S. Army Engineer Research and Development Center. Vicksburg, MS. U.S. Army Corps of Engineers Environmental Laboratory Corps of Engineers Wetlands Delineation Manual. Vicksburg, MS. U.S. Forest Service Upper Turnagain Landscape Assessment. Glacier Ranger District, USDA Forest Service, Chugach National Forest; Region 10, Alaska. Viereck, L.A.,C.T. Dyrness, A.R. Batten, and K.J. Wenzlick. (1992). The Alaska Vegetation Classification. United States Department of Agriculture, Forest Service, Pacific Northwest Research Station. General Technical Report PNW-GTR-286. Portland, Oregon. Seward Highway MP AKDOT&PF March 2008

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27 Vegetation Study Appendix A PLANT SPECIES LIST SEWARD HIGHWAY MP Alaska Vegetation Study

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29 Vegetation Study Common Name Scientific name Common Name Scientific name Common Yarrow...Achillea millefolium False azalea... Menziesia ferruginea Baneberry...Actaea rubra Single delight... Moneses uflora Rough bentgrass...agrostis scabra Sweetgale... Myrica gale Green alder...alnus crispa Devil's club... Oplopanax horridus Sitka alder...alnus sinuata Northern grass-of-parnassus... Parnassia palustris Thin-leaf alder...alnus tenuifolia White spruce... Picea glauca Kneeling Angelica...Angelica genuflexa Sitka spruce... Picea sitchensis Seawatch angelica...angelica lucida Leafy white orchid... Platanthera dilatata Lyre-leaf rockcress...arabis lyrata Seaside plantain... Plantago maritima Goatsbeard...Aruncus sylvester Large-flower bluegrass... Poa eminens Wormwood...Artemisia tilesii Fowl bluegrass... Poa palustris Alpine lady fern...athyrium filix-femina Kentucky bluegrass... Poa pratensis Swamp birch...betula nana Balsam poplar... Populus balsamifera Paper birch...betula papyrifera Silverweed... Potentilla anserina Northern groundcone...boschakia rossica Silverweed... Potentilla egedii Bluejoint reedgrass...calamagrostis canadensis Marsh cinquefoil... Potentilla palustris Water sedge...carex aquatilis Nootka alkali grass... Puccinellia nutkaensis Mud sedge...carex limosa Pink wintergreen... Pyrola asarifolia Lyngbye's sedge...carex lyngbyei White water butter-cup... Ranunculus aquatilis Merten's sedge...carex mertensii Seaside butter-cup... Ranunculus cymbalaria Western water-hemlock...cicuta douglasii Macoun's butter-cup... Ranunculus macoui Mackenzie water-hemlock...cicuta mackenziana Yellow rattle... Rhinanthus minor Pale bastard toadflax...comandra pallida Arctic raspberry... Rubus arcticus Hemlock-parsley...Cooselinum chinense Common red raspberry... Rubus idaeus Bunchberry...Cornus canadensis Strawberry-leaf raspberry...rubus pedatus Annual hawksbeard...crepis tectorum Arctic dock... Rumex arcticus Tufted hairgrass...deschampsia beringensis Western dock... Rumex fenestratus Tufted hairgrass...deschampsia cespitosa Felt-leaf willow... Salix alaxensis Mountain woodfern...dryopteris dilatata Barclay willow... Salix barclayi Sea lyme-grass...elymus arenarius Bebb willow... Salix bebbiana Tall fireweed...epilobium angustifolium Under-green willow... Salix commutata Marsh willow-herb...epilobium palustre Hooker's willow... Salix hookeriana Field horsetail...equisetum arvense Diamond-leaf willow... Salix plafolia Water horsetail...equisetum fluviatile Sitka willow... Salix sitchensis Meadow horsetail...equisetum pratense European red elder... Sambucus racemosa Variegated horsetail...equisetum variegatum Sitka burnet... Sanguisorba sitchensis Red fescue...festuca rubra Sitka burnet... Sanguisorba stipulata Northern bedstraw...galium boreale Greene's mountain-ash... Sorbus scopulina Small bedstraw...galium trifidum Northern burreed... Spargaum hyperboreum Sweet-scent bedstraw...galium triflorum Sitka starwort... Stellaria sitchana Large-leaf avens...geum macrophyllum Clasp-leaf twisted-stalk... Streptopus amplexifolius Oak fern...gymnocarpium dryopteris Common dandelion... Taraxacum officinale Cow-parsp...Heracleum lanatum Few-flower meadow-rue... Thalictrum sparsiflorum Smooth alumroot...heuchera glabra Narrow beech fern... Thelypteris phegopteris Meadow barley...hordeum brachyantherum Three-leaf foamflower... Tiarella trifoliata Arctic rush...juncus arcticus European starflower... Trientalis europaea Thread rush...juncus filiformis Alsike clover... Trifolium hybridum Vetchling peavine...lathyrus palustris White clover... Trifolium repens Beach pea...lathyrus maritimus Seaside arrow-grass... Triglochin maritimum Scotch lovage...ligusticum scothicum Marsh arrow-grass... Triglochin palustre Marsh felwort...lomatogoum rotatum Mountain hemlock... Tsuga mertensiana Nootka lupine...lupinus nootkatensis Stinging nettle... Urtica gracilis Stiff clubmoss...lycopidium annotinum Early blueberry... Vaccium ovalifolium White sweetclover...melilotus alba High-bush cranberry... Viburnum edule Buckbean...Menyanthes trifoliata Dwarf marsh violet... Viola epipsila ssp. repens

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31 Vegetation Study APPENDIX B REPRESENTATIVE COVER TYPE PHOTOGRAPHS SEWARD HIGHWAY MP Alaska Vegetation Study

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33 Open Sitka Spruce Forest Cover Type Photograph 1 Photograph 2

34 Closed Balsam Poplar Forest Cover Type Photograph 3 Photograph 4

35 Open Balsam Poplar Forest Cover Type Photograph 5 Photograph 6

36 Closed Tall Willow Scrub Cover Type Photograph 7 Photograph 8

37 Closed Tall Alder Scrub Cover Type Photograph 9 Photograph 10

38 Open Tall Willow Scrub Cover Type Photograph 11 Photograph 12

39 Open Tall Alder Scrub Cover Type Photograph 13 Photograph 14

40 Open Sweetgale-Graminoid Scrub Cover Type Photograph 15 Photograph 16

41 Elymus Meadow Cover Type Photograph 17 Photograph 18

42 Midgrass Herb Meadow Cover Type Photograph 19 Photograph 20

43 Hairgrass Meadow Cover Type Photograph 21 Photograph 22

44 Bluejoint Meadow Cover Type Photograph 23 Photograph 24

45 Bluejoint-Herb Meadow Cover Type Photograph 25 Photograph 26

46 Sedge-Shrub Wet Meadow Cover Type Photograph 27 Photograph 28

47 Halophytic Grass Wet Meadow Cover Type Photograph 29 Photograph 30

48 Halophytic Sedge Wet Meadow Cover Type Photograph 31 Photograph 32

49 Mixed Herb Meadow Cover Type Photograph 33 Photograph 34

50 Halophytic Herb Wet Meadow Cover Type Photograph 35 Photograph 36