3.0 Affected Environment - Knik Arm Bridge and Toll Authority

Knik Arm Crossing DraftFinal EIS
Affected Environment
Broadleaf forest
In the project direct effects Study Area, broadleaf forests are characterized by a canopy
dominated by paper birch with an understory composed of prickly rose, highbush cranberry
(Viburnum edule), fireweed, horsetails, and bluejoint reedgrass (KABATA 2006q). This
upland habitat type occurs across wide, flat areas and on low hills with well-drained soils.
In the indirect effects Study Area, broadleaf forests are characterized by a canopy of
cottonwood, aspen, or paper birch. Understory vegetation is highly variable, and may include
spirea, Labrador tea, tall blueberries, and rusty menziesia on more moist sites, and prickly
rose, and highbush cranberry, on drier sites. Common forbs include bluejoint reedgrass,
horsetails, and fireweed (USGS 1999).
Mixed needleleaf/broadleaf forest
In the project direct effects Study Area, mixed needleleaf/broadleaf forests have a canopy
dominated by white spruce and paper birch, with an understory of highbush cranberry, dwarf
dogwood (Cornus canadensis), lady fern (Athyrium filix-femina), prickly rose, and fireweed
(KABATA 2006q). This upland habitat type is common throughout the direct effects Study
Area, occurring over wide, flat areas with well-drained soil.
In the indirect effects Study Area, mixed forests are composed of an upper canopy mix of
paper birch, cottonwood, aspen, white spruce, and black spruce. Understory plant species
may include Labrador tea, horsetails and bluejoint reedgrass on more moist sites, and prickly
rose, highbush cranberry, dwarf dogwood, lady fern, and fireweed, on drier sites
(USGS 1999).
Tall and low shrub
In the direct effects Study Area, tall shrub habitat occurs along roadsides and on the coastal
bluff. This habitat type is dominated by a thick canopy of alder, with a sparse understory of
devil’s club, lady fern, horsetail, and bluejoint reedgrass (KABATA 2006q).
Dwarf shrub
In the indirect effects Study Area, dwarf shrub areas are characterized by plants generally
less than 1 foot tall and are dominated by dwarf birch and a variety of heath species. This
habitat type is common in peatland. Mosses (primarily Sphagnum sp.) are common in
peatland types (USGS 1999).
Dry and moist herb
Upland herb meadows are common throughout the direct effects Study Area, occurring
within the existing transmission line corridor. The dominant plant species is bluejoint
reedgrass, with prickly rose, devil’s club, red raspberry (Rubus idaeus), and red elderberry
(Sambucus racemosa) also present (KABATA 2006q).
12/18/07 3-189