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Riparian Woodland
<br /> Vegetation
<br /> A variety of riparian trees and shrubs forms a corridor along the banks of the
<br /> Mokelumne River, and an isolated group of riparian trees is found along the shore of one
<br /> of the lakes (Figure 3). Approximately 16 acres of riparian habitat are found at the project
<br /> site. The width of the riparian corridor along the Mokelumne River varies from one row
<br /> of trees immediately adjacent to the river to an area several hundred feet wide.
<br /> Dominant overstory species include black walnut,oregon ash,white alder,valley oak,
<br /> cottonwood, black willow, and interior live oak. Woody understory shrubs and small trees
<br /> include elderberry, sandbar willow, red willow, yellow willow, buttonbush, and dogwood.
<br /> Other woody, vinelike plants include wild grape, himalayan blackberry, California rose,
<br /> poison-oak, and snowberry.
<br /> Herbaceous understory vegetation is found along the edge of the river and in wetland
<br /> areas within the corridor. Dominant species include mugwort, Bermuda grass, English
<br /> plantain, creeping wildrye, watercress, smartweed, stinging nettles, baltic rush, and
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<br /> dallisgrass.
<br /> Wildlife
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<br /> Riparian vegetation along the Mokelumne River provides habitat for a diverse group
<br /> of resident and migratory wildlife. The significant decline in California's riparian habitat at
<br /> local, regional, and statewide levels makes remaining riparian areas especially valuable.
<br /> Bird species observed in the riparian corridor include great egrets, Nuttall's
<br /> woodpeckers, Bewick's wrens, plain titmice, bushtits, yellow-breasted chats, and yellow
<br /> warblers. A heron rookery located approximately 0.5 mile upstream of the project site had
<br /> about 40 great blue heron and a few great egret nests in spring 1990 (Yee pers. comm.).
<br /> Raptors observed during field surveys include red-shouldered hawks,red-tailed hawks,
<br /> American kestrels,and turkey vultures. Red-shouldered hawks and Cooper's hawks may use
<br /> riparian habitats on the project site for roosting and nesting. Wintering raptors that occur
<br /> in the area include sharp-shinned hawks, osprey, and bald eagles(Yee, Estey pers. comms.).
<br /> Mammals such as striped skunks, raccoons, ringtails, gray foxes, bobcats, and
<br /> mountain lions have been observed in the project vicinity(Messersmith,Baker pers.comms.)
<br /> These species range through the area and utilize the riparian system for foraging, cover, and
<br /> travel. The riparian system on the project site is further enhanced by large, open spaces on
<br /> adjacent sides: Van Assen Park and the Teichert Aggregate quarry.
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