Carbonera Creek - Ecology

Ecology

Riparian woodland vegetation is located Carbonera Creek and its tributaries. The 1990 Earth Metrics EIR identifies broadleaf deciduous trees as dominating this habitat and are able to survive because of the year-round presence of fresh water. Examples of such trees present in the riparian zone include California bay laurel (Umbellularia californica), boxelder (Acer negundo), California Sycamore (Platanus racemosa), black cottonwood (Populus trichocarpa), Bigleaf maple (Acer macrophyllum), white alder (Alnus rhombifolia), and various willows (Salix spp.). Invasive root systems of these trees are important in erosion control and their dense canopy provides food and shelter for a variety of birds and mammals, yielding high habitat value. The lush cover afforded by this habitat also provides wildlife with a suitable environment for breeding. Additional vegetation found along creek banks includes California blackberry (Rubus vitifolius), Himalaya blackberry (Rubus procerus), poison oak (Rhus diversiloba), baltic rush (Juncus balticus), redwood sorrel (Oxalis oregana), snowberry (Symphoricarpos rivularis), Coastal wood fern (Dryopteris arguta), and other herbaceous species and decaying vegetation.

The plant community Northern coastal scrub also exists in the Carbonera Creek catchment basin. This community is scattered throughout the basin, typically situated on windy, exposed sites with shallow, rocky soils. The community is dominated by California sagebrush (Artemisia californica); toyon (Heteromeles arbutifolia); coyote brush (Baccharis pilularis; California yerba santa (Eriodictyon californicum); and manzanita (Arctostaphylos spp.)

Within the Carbonera Creek watershed is one of the three known Maritime Coast Range Ponderosa Pine forests, a rare assemblage of vegetation narrowly restricted to sandy, infertile Zayante soils formed over Santa Margarita Sandstone. This habitat is only found in coastal Santa Cruz County and is found in a part of the Carbonera Creek catchment in the southwestern part of the City of Scotts Valley on the slopes of Mount Hermon, extending to the south. The surface soil and subsoil drain very rapidly and do not retain enough water to support local climax species such as Coast redwood or Douglas fir. The Ponderosa Pine (Pinus ponderosa) withstands the stresses of this xeric habitat and typifies the open plant community, which also supports rare species of flora such as the Bonny Doon manzanita (also called the silver-leaved manzanita) (Arctostaphylos silvicola) and the endangered Ben Lomond wallflower (Erysimum teretifolium). There are two Federally listed endangered species of insects within this sparse forest.

Aquatic species include Steelhead trout (Onchorhynchus gairdneri, formerly Salmo gairdneri) and Chinook salmon (Onchorhynchus tshawytscha), which migrate up the San Lorenzo River and its tributaries, including Carbonera Creek. For instance, these migratory fish species spawn in Carbonera Creek gravels downstream of the Santa's Village Area.