The Elder Creek Oak Woodland Preserve is a private preserve that encompasses 233 acres of primarily magnificently steep hills of blue oak woodland containing dozens of old-growth manzanitas–a biologist estimated the age of one at 250 years.
This preserve is located in the Elder Creek Watershed, which covers about 150 square miles and ranges in elevation from over 8000 feet to about 250 feet above sea level. Named biological communities within the watershed include: alpine, inland closed-cone coniferous forest, foothill scrub or mixed chaparral, blue oak woodland, oak savanna, riparian woodland, and valley grassland. Over 72 miles of streams and creeks make up the watershed, making it one of the longer ones on the west side of the northern Sacramento Valley.
Such a diverse land means there are many transitional zones between the differing plant communities–the riparian area of the Preserve being on one of them–with outliers being fairly common throughout. For example, finding black oak growing alongside douglas fir and canyon live oak at 3000 feet is not surprising, but finding them growing with buckeyes, silk tassel and blue oaks at 980 feet is quite astonishing!
The majority of the watershed is blue oak savanna (in most cases former woodland that has been “thinned”) and woodland. Blue oaks are incredibly well adapted to the dry-summer climate of about six rainless months in a row that include numerous days with temperatures well over 100-degrees Fahrenheit. These oaks, if situated in a drainage or seep, can grow rather vigorously and reach heights near 100 feet. In particularly dry locations, one arborist reported, they can grow so slowly that at 100 years of age they are only eight inches in diameter. This means there are many rather diminutive old-growth blue oaks in the watershed, dozens–maybe hundred–alone here on the Preserve.
Blue oaks are symbiotic with a wide variety of wildflowers including yampah, ookow, hound’s tongue, mule’s ears, and nearly the whole gamut of the lilies of northern California. We are just novice naturalists who dabble with identification, but we’ve counted over 100 species of forbs. The north slopes of the hills are particularly rich with species and are the densest with the common companions of blue oaks such as manzanita, toyon, mountain mahogany, spiny redberry, California buckeye, ferns, mosses and lichens. Several large patches of California brome and California melic are found in the hills and there are many large stands of purple needle grass as well. We share a seven-acre valley oak grove in the riparian area with our neighbor to the north, and within this grove there is a small, spring-fed grove of big leaf maple (very rare for such a low elevation). In the fall this is a favorite spot for black-tailed deer, great horned owls, wild turkeys and golden-crowned sparrows. In the winter, bobcats are frequently seen here and in the riparian willow/elder/California walnut/grape community in the sunken area that floods most winters. Titmice, acorn woodpeckers, flickers, nuthatches and bluebirds are year-round dwellers of blue oaks, and the seasonal community includes juncos, finches, tanagers and vireos. California quail frequent the low grassland and the shrubby areas.
Humans, deer, turkeys, pigs and coyotes are the common large animals of the watershed and the Preserve, and, occasionally, a bobcat, badger, skunk, porcupine, black bear or mountain lion makes an appearance. Beavers and river otters are present on the creeks, though their numbers are far too few.
Keystone species at the Preserve include woodrats, ground squirrels, bobcats, poison oak, valley oaks, blue oaks and acorn woodpeckers.
Other beloved species we encounter include brown and spotted towhees, Nuttall’s woodpeckers, black phoebes, woodrats, toads, treefrogs, and many others.