For better or worse, California is know for its incredibly agreeable climate. Winters here are extremely mild with rain being the most common form of precipitation, except at the highest elevations. What plants that do drop their leaves, mostly do so in response to lack of water, rather than in preparation for the coming of winter. This week's photo shows the canopy of healthy leaves on a coast live oak, a species native to California that keeps its leaves year-round. Backlit by the sun at about noon, it is hard to imagine that this is the middle of winter.
California lives under the sway of what is commonly known as a Mediterranean climate. Named for the cool, wet winters and hot, dry summers found in the countries surrounding the Mediterranean Sea, the seasonal changes in California match these conditions. Because of these wide seasonal variations, the plant communities blanketing the hills and valleys of California host some of world's greatest diversity of plant species. This is characteristic of the plant communities found in other Mediterranean climates around the world like South Africa, Chile, and Australia. While the species that comprise the plant communities in each of these areas are completely different, they share characteristics that are advantageous for survival in such a climate regime.
One such characteristic that is all too familiar to people in California is the propensity to burn. Because rains are restricted primarily to the months between November and March, the soil and plants become quite dry by the end of summer when hot, dry winds sweep down from the Great Basin area of North America toward the Pacific Ocean. Tinder dry at these times, the slightest spark can set off massive wildfires that consume tens of thousands of acres, and that can burn for weeks.
Known in California as Chaparral, this plant community has evolved to make fire part of its reproductive cycle. Many chaparral species have thick waxy leaves that prevent water loss, but that also serve as a great fuel source for fire. Similarly, many of these species are able to re-sprout from the root crowns below the scorched surface of the soil.
Perhaps the worst aspect of chaparral is that humans have decided that the places where it grows are also great places to build homes. As a result, the almost annual occurrence of fire in our mountains now potentially threatens many multimillion dollar homes that the fire protection services of local and state governments are forced to protect. Rather than avoiding these places as sites for homes, people continue to build new homes, or rebuild homes damaged or destroyed by fires in these same locations.
I've often heard it said that the definition of insanity is doing the same thing over and over again, and expecting a different result.
This week's photo was taken with a Canon EF 17-40 mm f/4 lens on an EOS 10D dSLR. The lens was zoomed to 40 mm and the exposure set to 1/90 sec at f/5.6 and ISO 100.