Effects of wildfire in Redwood Country
Our timeless giants stand exposed among charred and smoldering wreckage that once was the forest floor. Any surviving green vegetation looks out of place. The ground is smothered in white ash, the shrubs are black coals, and tree trunks - once rainbow-colored with red bark, green lichen, and a full spectrum of fungi and critters - are reduced to grays. All of the majesty and grandeur, the near-deification we ascribe to the redwood forest, stands in question.
Yet this same fire ultimately gives new life to the forest. Untouched by our emotions, the forest is busy with rebirth.
Dan Porter, former director of science and planning for Save the Redwoods League in San Francisco, reminds us "Fire has given us the redwood forest that we have today. It shapes how the forest looks; it shapes how it feels."
Take literally the metaphor of fire sweeping through the forest floor. A typical naturally occurring wildfire in a redwood forest tends to stay within six to 10 inches of the ground. It burns the leaf litter and low-lying vegetation. It burns the bases of bushes, leaving only a faint skeletal form of the charred, thickest branches. Depending on the speed and temperature of the fire, it can burn through thick redwood bark and eventually hollow out lower tree trunks. The fire rarely gets too high in old forests, however, because the lowest branches, which fire would need for climbing, may be 100 feet up.
A healthy fire may give the forest much more than it takes away. Like many conifer forests, redwood groves may depend on fire to regulate their nutrient cycles. Because the redwoods are so tall and expansive, they soak in most of the sun's energy before it gets a chance to feed understory vegetation. Similarly, the redwoods' bark and root systems consume vast amounts of water from fog and rain. This means that understory vegetation tends to be sparse and slow-growing. Because redwoods can live for thousands of years without falling over and decomposing, their massive loads of nutrients stay stored in the trees longer instead of regularly replenishing the soil as quickly as tropical or northeastern deciduous forests.
The remedy is fire. By burning the understory and sweeping debris from the forest, fires release stored nutrients into the soil, thus providing food for the many seeds and sprouts to follow. Fires also open spaces creating habitat niches for a diverse array of wildlife.
After a wildfire, you will soon see huckleberry bushes sprouting from their enlivened root systems, fiddleheads bursting into bright green sword and chain ferns, and thick mats of sorrel blanketing the soft forest floor. As the birds return, their calls echo throughout the forest in waves of excited song. In short order, the forest has not only recovered, but may be healthier than before. As Porter notes, "Biodiversity - life - is tied to fire." A healthy fire can help "renew" a forest, turning an overcrowded, tangled, and dark environment into an open, ecologically diverse forest filled with color and sound.
Fire scientists find that redwood forests may have burnt every 6 - 26 years over the past 500 - 1,000 years. Archeological evidence indicates occupation of California's coast by Native Americans for the past 10,000 years, and so both culture and climate have probably helped shape the history of forest fires in California. The fires may be sparked by coastal thunderstorms, which are rare but regular. In addition, there is evidence that Native Americans throughout the West burned select forests. By continually opening up forest understories, this custom promoted constant ecological renewal and contributed to biologically diverse landscapes. The result: abundance of varied foods and other resources for the people and other animals and plants sharing the land.
Since European settlement, after decades of fire suppression, many Western forests other than redwood forests have grown overbearingly crowded with understory plants. Add to this a few years of drought and a lightning storm, and suddenly a massive forest fire starts blazing. With a tall, dry understory, the fire progresses from the forest floor to the medium-sized bushes, and eventually climbs to the tree branches themselves. When this happens, the fire doesn't merely sweep through the forest but it wholly consumes it. Scientists think coast redwood forests are less prone to such `crown fires' because they are relatively wet. Continued supression of fire, however, stands to influence fire behavior. Fire scientists are actively studying the effects of recent wildfires on the forest and its inhabitants.
Today less than 5% of California's ancient redwood forests remain standing. "We need a new conservation ethic that extends what conservationist Aldo Leopold said, what John Muir said - updated for the 21st century," Porter states. He's referring to an ethic that he has helped foster through his work with Save the Redwoods League and beyond. It's an ethic of cooperation and virtue, in which humans "once again become an integral part of the ecosystem." This is a practice of caring for the forests not simply because we appreciate them or need them, but because in fact we are part of them. To fulfill this ethic, we must expand our stewardship role from the forest to the fires. We must continue to learn about and participate in the curious abundance that fire can offer.
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To see the reviving effects of fire, try visiting a redwood forest after a wildfire.
- A wildfire swept through the Montgomery Woods State Natural Reserve in Mendocino County northwest of Ukiah in the summer of 2008. This is a good place to see how a forest looks just one year after a wildfire. To learn more about the park and for information about visiting, check out www.parks.ca.gov or call (707) 937-5804.
- In the winter of 2003 the Canoe Fire swept through Humboldt Redwoods State Park in Humboldt County. Take a trip to see how a forest looks nearly six years after a wildfire. To learn more about the park and for information about visiting, check out www.parks.ca.gov/?page_id=425 or call (707) 946-2263.
For more information on redwood and giant-sequoia parks, and to find festivals, tours, seasonal highlights, and more, visit Save the Redwoods League's new Google map and calendar of Events and Activities