The Black Oak

Black oak grove on the Mt. San Bernadino Trail

The black oak is one of Southern California’s most beautiful non-coniferous trees. Getting its name from the dark color of its bark, the black oak is also the most colorful tree in Southern California. They grow old, large, and gnarly, and have a stately presence in the mixed oak and conifer woodlands in local mountains.

Spring

Summer

 

Fall

Black oak leaves express quite a range of color. In spring, they emerge a brilliant shade of magenta that slowly fades into a pale green. During Spring, the leaves take on a bright green hue shading into a deep green by late summer. In the fall, the black oak’s leaves turn a brilliant gold with a pleasing transition between light greens to yellows. Walk under a black oaks dark branches in winter, and you’ll kick your way through sizable piles of leaves.

Lone black oak on Kanaka Flat, Julian

There are not a lot of deciduous trees in Southern California. All of them reside along watercourses, which reflect a wetter ecology like Northern California. The black oak inhabit rolling hills and mountains above 4,000′ where it forms woodlands and forests with Jeffrey pine, incense cedar, white fir, and evergreen canyon oaks. These woodlands and forests are present in San Diego, although they are not as common as they once were.

Oak and Jeffrey Pine forest at Wooded Hill on Mt. Laguna

The black oak was an important staple food for people and animals alike. The people who lived of the oaks are long gone, leaving hikers and mountain bikers (and cars full of imported fire wood) as their companions. The oaks still do a tremendous job of feeding birds, though. Acorn nutcrackers collect acorns into thousands of wholes they’ve drilled into dead pines. The birds return to feast on the nuts during lean times.

Black oak in November at Observatory Campground

The trouble with the change to the black oaks environment is that foreign pests have been a problem. In the late 90’s, somebody used wood brought in from Mexico during camping trips. The wood carried the Gold Spotted Oak Borer, which is common (and defensible) in Mexico’s woodlands. However, black oaks have no defense, and when coupled with drought, which already weakens trees, black oaks have proven highly susceptible to the pest.

Spring leaves on the Five Oaks Trail to Volcan Mountain, Julian

During the 90’s and 00’s, San Diego lost a lot of black oaks to bark beetles imported from outside. Drought compounded things, and many dead black oaks began resembling bonfires waiting to burn. In 2003, the Cedar Fire burned hundreds of thousands of acres of San Diego’s backcountry, and it took a lot of black oaks in the Cuyamacas and Julian area down with it.

Early morning November on the Observatory Trail

Fortunately, black oaks are fire-adapted, unlike conifers which don’t have a defense for large, hot fires. Many of the black oaks burned over the last ten years have begun to re-sprout from their root systems. This is similar to chaparral plants like manzanita and laurel sumac which resprout from their root systems and take advantage of the newly created space. The black oaks will eventually return, barring further fires, droughts, and pests.

Spring sunrise on the Boucher Hill Trail

For now, many of these trees still grace some of the most beautiful parts of Southern California. Big Bear, Idyllwild, Palomar, and Julian all have them. Their presences adds some of the charm to these mountain hideaway towns. The populations in Big Bear and Palomar seem safe for now, although the oaks in Idyllwild have shown signs of bark beetle attacks. All the more reason to burn your firewood where you buy it to avoid importing pests.

 

A rare red-tinge after a snowstorm on the Mt. San Bernadino Trail