Opening the San Francisco Bay Bioregion Office of Biohabitats has been a very exciting opportunity for me. With my background and interest in both ecology and design and having lived in the Bay Area since my early childhood, I am pleased to be able to apply all of my skills to our current work in California. I did not, however, expect that I would use my design and ecology skills to choose a leaf for the San Francisco Bay Bioregion Office logo. In case you were not aware, each of Biohabitats’ bioregional offices has its own logo, complete with a leaf of a local, native tree that has significance in the bioregion. So, I undertook my quest for the perfect leaf.
While many people associate the Coast Redwood or the Giant Sequoia with California, many Californians think of the rolling golden hills of the oak savannah as the state’s dominant landscape. California is home to 18 species of Oak trees, with 30 distinct variety types covering about 13 million acres of the state in woodlands and forest.
Oak trees are a prominent landscape element in many of my childhood memories. I enjoyed many a picnic in the shaded, dome under the wide, arching canopy of gnarled branches. I continue to enjoy their beauty, shade, and the occasional climbing opportunity they provide. The large, twisted, low growing branches invite climbing, but also encourage reclining and lounging. And, of course, there is the teeming life associated with the trees: caterpillars, moths, spiders and salamanders. The amazing granaries of red headed woodpeckers; the perfect perch for a red-tailed hawk. Oh, the hours one can spend searching for and watching the diversity of life amidst these trees.
California’s oak savannahs and woodlands contain the highest biodiversity of California ecosystems, with more than 300 animal species depending on them for food and shelter. One must be respectful and careful, however. One of my leaf collection expeditions resulted in a wasp sting, as I inadvertently disturbed a ground nest in an old stump.
I specifically chose the California blue oak, Quercus douglasii as the tree for Biohabitats’ San Francisco Bay Bioregion office logo for a variety of reasons. The blue oak is California’s dominant oak species, covering over 18,000 acres of the state. In the San Francisco Bay Bioregion, oaks represent more than 95 % of the native tree species, with blue oaks comprising about a third of this number. A mature blue oak is a very majestic specimen. The blue tint of their leaves is due to the thick, waxy coating on the upper leaf surface that enables them to survive the dry hot summers in California, where they receive only 15 to 35 inches of rain during the winter and spring months. Being a designer, I also chose this tree due to the irregular and unique shape of the leaf. The leaves are typically between 3/4 to 1 1/2-inch long. They vary widely in shape and margin, with some being a simple oblong leaf, and others having irregular wavy margins or shallow lobes. The blue oaks range is exclusive to California. They can be found in the foothills bordering hot interior valleys in poor soils.
I hope that when you see the logo for the Biohabitats’ San Francisco Bay Bioregion, you will be reminded of the rolling, golden hills of the oak savannah, the diversity of life and habitats supported by the Bay Area and the state at large, and how we work to inspire communities to rediscover a sense of place through preserving indigenous ecosystems, restoring biological diversity, and inspiring ecological stewardship. I hope that you, too, have the chance to enjoy the sheer beauty of these oaks, the diversity of indigenous wildlife they support, and perhaps even a climb into or a picnic under these majestic trees.
Gaman, Tom and Jeffrey Firman. Oaks 2040: The Status and Future of Oaks in California. Produced by for the California Oak Foundation. November 2006 available online at www.californiaoaks.org/html/reference.html
Pavlik, Bruce, Pamela Muick, Sharon Johnson, and Marjorie Popper. Oaks of California. Cachuma Press and the California Oak Foundation. 1991