Climate change and the recent five-year drought in California have now rendered 129 million trees dead in the Sierra Nevada mountains. As a result, they are more susceptible to catastrophic wildfires like we’ve seen this fall in the state’s coastal areas. California’s Sierra Nevada Conservancy has an informative webpage and videos dedicated to educating the public about the urgent need to manage the forests better.
The first video describes the immediate need for action, particularly given the forests’ role as a carbon sink, which could turn to carbon emitter without better management:
The next video shows the risk of continued fire suppression and need for more controlled burns:
The final video shows what controlled burns can do to restore the forest ecosystem and provide carbon benefits:
But as UC Berkeley forest expert Van Butsic described in a recent interview with Water Deeply, the solutions will be controversial, most likely requiring “mechanical thinning” in forests that some environmental groups oppose. Yet as the videos above make clear, the price of continued inaction and fire suppression will only exacerbate the environmental catastrophe we are facing in these beautiful mountains.
I was fortunate to spend many childhood summers in the Sierra Nevada forests around Lake Tahoe, exploring and enjoying. But as a child, I had no idea that the seemingly pristine forests that I loved, which seemed so ancient and enduring, were in fact new environments, the product of complete ecological devastation starting in the late 1800s.
Lake Tahoe forests used to feature massive, thousands-year-old pine trees, spaced well apart on land where the underbrush was cleared out by regular forest fires, usually intentionally set by the local Washoe Indians. The Washoe summered by the Lake and wintered in the Nevada desert. These trees were so big they rivaled Sequoias in size.
But when the Washoe were systematically displaced and killed by invading Americans in the mid-1800s, with a corresponding loss in decision-making authority over land use, the forests were placed at tremendous risk. With gold discovered nearby and then silver in Nevada, the huge mining companies that went to work needed lumber for their mines. They began completely clear-cutting the forests, and the wealth from the mines enriched San Francisco and made it the city we know today. The pattern of clear cut scars are still visible in the mountains above Sand Harbor in Nevada, where loggers constructed giant flues to send the old growth trunks shooting down into the lake below, to be barged off to Nevada.
In the wake of this annihilation and forest fire suppression, fast-growing fir trees moved in. These fir trees weren’t as drought and fire resistant as the pines they out-competed and replaced, and they grew up in clumps, all of the same generation.
So the result for the past century has been a thick, overgrown forest, prone to intense wildfires that devastate the landscape and lead to erosion and a repeat of the ill-fated, fast-growth cycle. And now with climate change increasing the severity of the droughts and intensity of the summer heats, these fires are only becoming more common and severe.
In short, the American invasion of these forested lands has been a complete ecological and aesthetic disaster. It will take thousands of years to restore the forests to their previous glory, assuming a changing climate doesn’t wipe the forest species out completely. But we might as well begin now.
With that in mind, I’ve enjoyed exploring Burton Creek State Park in the Tahoe Basin in the last 15 years especially, as long-term work to restore the forests has begun. CalFire has been systematically thinning the overgrown firs and clearing the forest floor into burn piles. Here’s an example from this summer:
And now with the first snowfall in the mountains, CalFire has begun burning these piles, with the results visible here:
The foresters have been leaving behind the pine trees, focusing only on firs which can be shipped to build homes in the American southeast. One day, if climate change doesn’t get them, these pine trees will grow large like their ancestors. Their pine needles will kill off and prevent rival trees from growing below, leading to a clear under-story. The forest will once again tolerate and benefit from regular “cool” fires that don’t destroy the big trees. Here’s an example from an area that was thinned about five years ago:
I’ll never live to see these forests restored to their old glory, but you can see examples of intact old-growth forest in places like D.L. Bliss State Park on Emerald Bay on the Lake.
But in the meantime, I’m glad to be witnessing the beginning of the rebirth of these lands, as the once unhealthy forests become healthy again.
California’s unprecedented drought is finally bringing down some of the big trees in the state. After four years of little rain, they’re starting to succumb in droves. I was struck by this when in Yosemite a few weeks ago. Huge stands of pines looked like ghosts, dotting the mountains almost like fall colors in the east. The picture above (not mine) illustrates it to some extent.
The Brown Administration in California is trying to make lemonade out of these lemons. Specifically, they want to clear the trees out rather than have them burn in destructive, out-of-control wildfires and then use the biomass to generate electricity. As the San Gabriel Valley Tribune reports:
The governor is asking various state agencies, including Caltrans and Cal Fire, to identify the areas where dead trees pose the highest risks. “He is directing state agencies to remove dead and dying trees in those areas,” said Greg Renick, information officer with the Governor’s Office of Emergency Services Southern Region.
He said the governor is asking the state to provide counties in affected areas with heavy equipment, such as wood chippers. Caltrans can use the wood chips as mulch, according to the proclamation. Brown may use his emergency powers to increase the days allowed for burning tree waste. He may ask the California Public Utilities Commission to fast track new bio-fuel plants using tree waste from impacted areas.
I’m all in favor of using this kind of biomass, as well as biomass from thinning forests more generally, as feedstocks for energy production. Our forests in California and across the west are badly overgrown after 19th century clear-cutting followed by a century or more of forest fire suppression. We need to improve the health of the forest and ensure that these feedstocks don’t just burn up in catastrophic wildfires, returning more carbon to the atmosphere. Instead, we can use that carbon to offset petroleum and other fossil fuel emissions through bioenergy.
