A good year for acorns

I woke up this morning with the cognizance that my summer blankets were no longer keeping me warm. The calendar confirmed my suspicion that fall is upon us.

With the equinox, it is not only the calendar that indicates autumn. Light breaks the morning later and later. The cool crisp air of dawn and dusk shimmers as if diffused through crystal. Farmers markets sell the season's late summer tomatoes and the first harvest of winter squash.

Most conspicuously, the jays and squirrels herald the changing season as they frantically gather and store seeds.

Although not as pronounced as the northeast, Southern California does show signs of yet another year ending. Reading the trees will tell you. The fluorescent green of new spring growth turns to a dark hearty green in summer and then to brown in the fall. If it is a tree that does not lose its leaves, look to the layers of dust that accumulate until the first rains.

But even beyond the foliage, the fruits of the trees share a story. Large green-red cherries dangle from the hollyleaf cherry (Prunus ilicifolia). Single samaras of the velvet ash (Fraxinus velutina) spin wildly to the ground.

But most prolific this year are the acorns, dripping from the oaks. This year seems to be a mast year—a year when one tree species produces an abundance of fruit. This year, it's the acorn.

Not just for squirrels

Acorns hold a formidable history in California and worldwide because oaks are widely distributed across the continents. Once the staple of many native people, the use of the acorn has diminished with increased commercial farming, except for some Native American cultures and in Korea. Dotorimuk, acorn jelly, and dotori gook soo, acorn noodles, are common foods eaten daily in Korea.

Because of their high nutritional value, acorns are prized by other animals. Birds, insects and mammals of all sizes often depend on acorns to see them through the winter. As much as 25 percent of a deer's fall diet could be made up of acorns.

Although percentages of nutrients vary between species, all acorns are an excellent source of protein, carbohydrates, fats, minerals, and vitamins such as calcium, phosphorous, potassium and niacin.

Because acorns are filled with tannins, many mammals have adapted to digest tannic acids. Different acorn species contain different amounts of tannins, and animals have been observed to prefer those acorns with a lower acid content.

While not physiologically adapted to digesting tannic acid, humans have culturally adapted by devising multiple ways to leach the tannins from the acorns. Leaving acorns buried in the ground, submerging acorns in running water or even placing them in the tank of a toilet are just a few of many effective ways to leach acorns. The book, "It Will Live Forever: Traditional Yosemite Indian Acorn Preparation," written by Beverly Ortiz as told by Julia Parker, is an excellent narrative on the cultural and nutritional necessity of acorns.

In the Santa Monica Mountains, three common acorns are known to the birds and mammals: the valley oak (Quercus lobata), the scrub oak (Quercus berberidifolia) and the coast live oak (Quercus agrifolia). You may also come upon the canyon live oak (Quercus chrysolepis), although not as frequently.

In a nutshell

Acorns are the fruiting body of the Quercus flower and begin growing in summer. They are green in late summer and early autumn and begin to brown later in the fall. For easier identification, both the acorn and the cup, which covers the top of the acorn and attaches to the tree, should be available.

Acorns of the valley oak are narrow and conical. I find that they often seem to develop ridges or stripes that run lengthwise down the acorn. They grow between 1¼ and 2 inches long. The acorn cups are deep and bowl-shaped, only covering the base of the acorn.

Differing in both shape and size, the scrub oak acorns are shorter and more egg-shaped, not ending in a point. They grow between approximately ½ and 1¼ inches long. Their acorn cup encloses 33 percent of the nut and has warty scales.

Somewhere between the valley oak and the scrub oak are the coast live oak acorns; long and slender, they range from conical to eggshaped. They grow between ¾ and 1½ inches long. Having thick papery scales, the cup covers approximately 25 percent of the acorn.

As fall comes upon us, I look fondly to the animals gathering acorns and remember the words of Julia Parker. In making a distinction between gathering and collecting, she advises, "Gathering implies respectfully taking only what you need and respectfully giving back for what you take . . . (collecting) implies a more wanton thoughtless hoarding, with no attention paid to the method used or quantity taken. . . . It is only by gathering responsibly that one guarantees the future harvest."

So gather well.

Meghan Walla-Murphy can be reached at the following e-mail: mwallamurphy@yahoo.com.