(an article for an upscale El Dorado County neighborhood magazine)
Oak Trees: Symbols of Serrano
By Betty Sederquist
For the first people of California, oak trees were life itself. Indeed, a Maidu creation myth declared that the Creator’s first act after forming dry land was to cause a great oak tree with 12 varieties of acorns to spring up. Legend has it that when a white man cut this tree in the 1840s, the stump flowed with blood. As every fourth-grader knows, acorns were the main food of the California Indians. Leached of tannic acid and pounded into a flour-like substance, acorn meal is loaded with nutrients. Natives most prized black oak acorns because of their size and high fat content.
Today most of us look to oaks for their beauty, not their food. El Dorado Hills is blessed with an abundance of these magnificent trees. Of the 18 to 20 species of oaks found in the state, six thrive in El Dorado Hills. The dominant front yard tree for Serrano homes is the oak, and the oak is also the backyard tree of choice for homes backing onto open space. Oak trees add to property values, but they’re also important for other reasons, says Virginia Meyer, a local botanist and college professor who enthusiastically advocates for these trees. “Once you get to know them, you become aware of other forms of life that depend on oaks.” She adds, “No part of an oak is not used by some kind of animal.” She points out that acorn woodpeckers, for example, have evolved a complex family structure in which aunt and uncle birds take care of nieces and nephews. If their oak tree homes are destroyed, the family falls apart. The medium-sized, red-capped birds harvest acorns directly from oaks and cache them in small holes in communal storage trees known as “granaries.” Up to 15 birds will share and defend a granary.
Of California’s 169 terrestrial mammals, at least 60 use oak communities to sustain themselves. Mule deer and bears find the acorns to be delectable. There are stories from Gold Rush times of grizzlies pounding their weight against oaks in an effort to drop their acorns. Insects thrive in oak woodlands, and the birds that depend on them.
Many animals that depend on oaks for food and shelter in turn sustain the trees. An individual scrub jay, for example, may bury up to 5,000 acorns in a season but will only relocate and consume a third to a half of them. Western gray squirrels also do their part in burying acorns and forgetting them.
Sometimes the life forms are smaller. For example, oaks host more gall insects that any other native tree or shrub in the West. Tiny wasps are responsible for the galls, which can take on many different forms: tiny cups, saucers, stars, balls, sea urchins and more.
Oak species vary according to micro-habitats. “We have a transition from valley grasslands to the foothills which include a mosaic of different types of grasses and oak woodlands,” says Meyer. “What you have depends on several things: soil type, direction of the slope, availability of water, ratio of rock to soil, and the fire regime—what kinds of fires have passed through the area.”
California oaks have adapted amazingly to the hot, dry conditions typical of a California summer. Indeed, watering local oaks in the summer can kill the tree (see side article). The blue oak in particular thrives in these harsh conditions. Common in El Dorado Hills, this deciduous, slow-growing tree typically has a single trunk and light-colored bark. Thriving in dry, rocky places, the blue oak’s grayish-green leaves reflect light and the waxy coating keeps water in.
As El Dorado Hills has grown, the folks responsible for planning growth have taken oak preservation seriously. In developing Serrano, for example, Parker Development Company’s strategy has been to build around trees when possible. Road construction has accommodated heritage oaks, and the trees are a beautiful feature of the golf course. Of necessity, a few trees have been removed. Parker Development has made a concerted effort to replace these trees in open space plantings. Blue and valley oak acorns were harvested in September 2004 in nearby undeveloped Marble Valley south of Highway 50 and Bass Lake Road. The current planting along El Dorado Hills Boulevard, done by Circuit Rider Productions of Sonoma County, involves 9,600 protective tubes, with three to five acorns in each tube. Circuit Rider anticipates a survival rate of 50 percent or less. Serrano’s goal is to support 70 live oak trees per acre throughout the 125 acres of open space. Last year’s plantings cost $86,000. Since the inception of the revegetation program, Parker has spent approximately $300,000. For its tree preservation and planting efforts, Serrano won a 2005 Award of Excellent in The National Arbor Day Foundation’s Building for Greener Communities National Conference last September in Nebraska City, Nebraska.
Several areas in El Dorado Hills offer great oak viewing. Try walking the trail along New York Creek for views of several species. Wild Oaks Park on El Dorado Hills Boulevard features most of the common oaks of the area.
In the language of the Pomos, one of California’s Native tribes, their word for oak, chiskale, means “beautiful tree.” And in that way, an abundance of beauty blesses El Dorado Hills.
