Why are Wildfires so Prevalent in California

After a fire in the California chaparral, the cycle of life continues. Some plants, like chamise, sprout quickly from their low crowns. Others, like the twisted Bishop pine, spread their seeds on land now free from competition. From a human point of view, the land heals, but for this biome, adapted to a fire every twenty years or so, life regenerates, as it has for centuries, as it is meant to do.


Two special kinds of plants grow in some areas of California. A group of plants hat tolerates fire, or even promotes it to kill the competition, is the pyrophytes, the fire-plants. Another group does not merely tolerate wildfire; it needs it to produce the next generation. These are the pyrophiles, which translated from the Greek means the fire-lovers. For millennia, parts of California have had an ecology which depends upon periodic cleansing fire.


After a fire in the Giant Sequoias of the Sierras, seeds sprout that might start new groves. New Sequoias grow only in mineral soils, in full sunlight, and free from competition. Seeds may sprout in the damp duff beneath the underlayer in spring, but will die as the duff dries out with advancing summer. Wildfire clears the glades of competing species that would shade out seedlings.


Fire also brings currents of hot air into the high crowns of these trees, drying and opening the cones. So the seeds land on soil that has been cleared for them. These plants need fire to live. Not massive annihilating fires, but cyclic fire that comes perhaps every twenty-five years. Small fires suppress White Fir. These shorter trees are thought to form ladders which intense fires can climb into the crowns of the ancient Sequoias and kill them, when fires are rare.


Yet California also has large and growing cities. From these cities come a fraction of the population, whether comfortable or struggling, who want to move back to the land. Fire is suppressed in California, to protect the lives and property of these people, as well as grazing, agricultural, timber, and mining interests. Many small fires are not allowed to happen. Fires, when they finally break free, are huge, and bring devastation.


The Coast Redwood has bark that is thick and full of tannin, and resists fire. Its foliage starts high, as its lower branches die and fall off in the shade of these tall trees. When a tree falls, whether from insects, accident, or man, new trees sprout in a line along its trunk. And fairy rings form, new trees around the circle where a huge old tree was burned away. Without fire, some experts believe, these coastal enclaves would hold Western Hemlock, a pretty tree, but not the soaring Redwood.


Much of California has a Mediterranean climate, with a hot dry season and a cool rainy one. One plant adaptation to this climate is a tolerance to or even a need for fire. Paradoxically, California has huge wildfires because we suppress fire. If small fires have room to burn, if damages from small fires are tolerated, if zoning and insurance regulations are formulated in a way that accepts the realities of this climate, then this green and golden state can live with our rejuvenating fires.