Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Section 3.5. Biological Resources
Grassland Communities
Grassland communities found on the Project site include non-native annual
grassland, wildflower fields, purple needlegrass grassland, and coastal prairie.
Each of these is described below.
Non-native Annual Grassland
Non-native annual grassland vegetation is the principal plant community in the
watershed, totaling approximately 877.5 acres. The dominant grass species are
soft chess and Italian ryegrass, but dense stands of medusahead are also present.
The grasslands are heavily grazed and support an abundance of invasive nonnative
species, including bellardia, parentucellia, purple star-thistle, yellow starthistle,
artichoke thistle, and Italian thistle. Additionally, non-native annual
grasslands support widespread, but low density, native grassland species,
including bunchgrasses.
Non-native annual grasslands support numerous small mammals such as deer
mice, California meadow vole, western harvest mouse, which in turn become
prey for raptors including red-tailed hawk, American kestrel, and great-horned
owl. Additionally, state species of special concern, northern harrier and golden
eagle, and state fully protected white-tailed kite have been documented to use the
site for foraging. These communities also provide foraging and nesting habitat
for burrowing owl. Individual owls have been documented to use the Action area
as wintering habitat and have been recorded numerous times in the areas north of
Highway 37.
Wildflower Fields
Wildflower fields are plant communities dominated by native herbaceous
wildflowers. This plant community, which is present on about 15.5 acres of the
Project site, primarily occurs at scattered locations within the watershed, mostly
on upper hill slopes. Non-native annual grasses are still a major component of
this plant community, but they occur at lower densities and are of smaller stature,
and the wildflowers exhibit a conspicuous floral display. Both soft chess and
Italian ryegrass are co-dominant grasses with a third non-native grass, little
quaking grass. Conspicuous native wildflowers in this community include
Johnny-jump-up, common yarrow, annual agoseris, stemless morning-glory,
valley tassels, purple owl's-clover, California poppy, royal larkspur, blue dicks,
lomatium, yellow lotus, miniature lupine, western lupine, sky lupine, dye
popcornflower, checker mallow, dwarf sac clover, pinpoint clover, small-headed
clover, Johnny tuck, Ithuriel's spear, purple sanicle, and narrow-leaved mule-ears.
Extensive stands of Johnny-jump-up (Viola pedunculata) were also reported to
occur in this community (Wetlands and Water Resources 2005b). Wildflower
fields support similar wildlife species as is described for non-native annual
grasslands.
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
3.5-15
April 2012