Mediterranean Region
Michael Ellis

There are five areas of the world that biologists refer to as Mediterranean Regions. Obviously one is the area around the Mediterranean Sea. Another is the extreme southern tip of Africa, the so-called Cape Region, the next is Chile and a bit of Argentina, The fourth is the northwest coast of Australia and the last is the state of California. A casual look at local landscaping plants reveals this international flavor in our yards and parks — French broom, Hottentot Fig (ice plant), eucalyptus, and pampas grass, just to name a few. When the Spanish first visited Mexico the wild hillsides reminded them of Spain, especially areas where the chapparo oak grew, a dense and shrubby tree. So they named those areas the chaparral.

These regions are characterized mild winters, that is usually no severe killing frosts or heavy snow. Precipitation is limited to the winter months, but it sometimes comes in very large amounts. Spring is followed by a very hot and dry extended summer. Tropical storms occasionally create lightning in the fall touching off wild fires. In other words periodic floods and catastrophic fires have always been part of this biological scene, even without the influence of humans.

Plants have evolved to cope with these conditions. After floods sweep through low-lying areas, alders and willows rapidly recolonize. Seeds of nettle, cattail, rushes, and tule immediately germinate and begin growing. Some areas of Pt Reyes devastated by the Great Flood of Jan. 4th, 1982 are now covered with alders; some trees over 25′ tall.

We average only three lightning days a year in the Bay area, but that’s enough to make fire a definite part of the scene. The thick, fibrous bark of redwoods protects the tree from burning; some of the trees in Muir Woods have lived through a hundred fires. The so-called fire pines (Grey, Bishop, and Monterey) do burn but their seeds actually require heat to germinate. And thousands of baby pines sprout immediately after a fire. Shrubs in the chaparral are full of oils and resins; they burn quickly right down to the ground. But they rapidly bounce back, sprouting from underground protected root crowns. In 1984 small areas of Mt. Tam were purposely burned; they have totally recovered.

We often succeed in suppressing fires and controlling floods. This gives us the comfortable illusion that humans are in control. The terrible fire in Oakland is a slap in the face from nature and a reminder that we are part of and not above nature.

That’s the deal living on this planet. When you build a house in a flood zone, expect it to flood, when you build a house in a fire zone expect it to burn. When you build a house on an earthquake fault, expect it to shake. It’s OK to be disappointed when it happens, just don’t be surprised.

This is Michael Ellis with a Perspective.



Posted on

November 6, 2010