Forests After Fire
While some seeds wait for light, others wait for fire.
By now it’s a familiar site, these sentinels of devastation. This is what remains of the Caldor Fire that started on August 14th, 2021, and burned for two months. It raged over three counties: El Dorado, Amador and Alpine in the El Dorado National Forest. 46-miles of Highway 50, a major route to South Lake Tahoe, was closed to traffic for a month. I recently drove through this area and was immediately sent back to another fire in another forest.
Seven years ago, I traveled to the Rim Fire near Yosemite. I wanted to learn how forests recover from fire. I met a man who’d discovered old forestry research maps from 1929. As we all know by now, the past seven years proves that climate events are accelerating in both severity and frequency. What I came away with seven years ago was a little hope that a forest could eventually recover.
The following is an essay I wrote for the Sacramento Bee as part of my freelance Op-Ed contributions in the Sunday Forum, 2011–2019. The series was called California Sketches, and combined short-form essay with my paintings. In revisiting this essay, I include photography that wasn’t in the original essay.
From “A Walk Through the Forest,” August 2014
After the Rim fire devastated more than 250,000 acres of the Sierra Nevada and part of Yosemite National Park last year, I wondered how forests recover from catastrophic fire and what the process looks like.
One answer can be found in an experimental research forest about 30 miles east of Sonora, in an area that hasn’t experienced a forest fire since 1889. An ecologist discovered old research maps that led to an experiment to measure how forests best recover from fire, to learn what creates a more diverse and resilient forest.
An ecologist finds research maps from 1929
Eight years ago, Eric Knapp, an ecologist with the U.S. Forest Service, discovered 1929 research maps in a dusty cupboard in his office. As if on a treasure hunt, he searched the National Archives and found corresponding records in old leather-bound ledgers. He followed the maps into the Stanislaus-Tuolumne National Forest and found the original research sites.
He found identification tags still nailed to the trunks. Knapp remapped each site to compare how the forest had changed over 85 years — from soil to shrubs to trees and to the forest canopy.
Knapp and his student assistants preserved the forest sites from the 1929 map and established new, adjacent study areas. They performed prescribed burns last fall. They are comparing two main management concepts, documenting restorative capacity- new growth and wildlife, in each of the two experimental areas. One, the variable groups of trees and spacing, characteristic of natural forest structure, and two, even spacing of a highly altered forest, as is often found in harvesting.
Knapp sends me into the burned experimental areas with his assistants. We move softly over hot, dusty soil, ash poofs into air with each step. One raven calls and several bright orange butterflies provide the only excitement in this hushed place.
Bark looks and feels like burned popcorn.
Ominous holes pit the forest floor, evidence of once mighty cedar, oak, fir and pine. The ground is deceptive. I’m warned to avoid areas where fire has devoured trunks and followed mighty roots far into the earth, leaving treacherous voids just under the surface.
Twenty months after the prescribed burns, I can clearly see the difference between the two experiments. In the first, variable spacing allows sun to reach the forest floor. While some seeds wait for light, others wait for fire. Lilac seeds that can hide in soil for a hundred years have been liberated, sprouting green shoots from the barren soil. Vibrant green oak leaves sprout from stumps.
In the second experiment, the shade of uniformly dense trees has prevented new growth. I touch the remnants of a pine bough, brittle, sharp and dangerous. The surviving canopy above provides the only color in this barren landscape.
Knapp is optimistic but says, “We don’t manage for short-term conclusions, but for long-term. Maybe in five years, we’ll have answers.” The original plots remain, quiet testimony as to how a forest wants to be.
The Rim fire is a landscape of extremes. Patchy forest and meadows are flourishing with grasses, lupine, lilies and tree seedlings. Vastly scorched areas, sterilized of life producing plants, must depend on man and the wind. Or take another 150 years to recover.
Next up: how fire threatens water sources. My 2014 visit to Hetch Hetchy, a major water source for the San Francisco Bay Area, was threatened by the Rim Fire.
