Southern California is always in the news for devastating wildfires torching whole neighborhoods to the ground, so surely the state could benefit from controlled burning, right? That's what fire managers thought for a long time. In their efforts to control the annual blazes, they frequently set fire to the chaparral, a dense, thorny, shrubby tangle of vegetation that covers the canyon-sides.
All that burning did absolutely nothing to lessen wildfires or mitigate the damage they caused. Now researchers are beginning to understand why that is. Controlled burns help reduce the prevalence and impact of wildfires in certain kinds of forests where, if left to themselves, the woodlands will ignite every 10 to 15 years.
But chaparral isn't that kind of vegetation. When experts studied the geological record, they realized that, on its own, chaparral goes up in flames only once every 100 years or so. And when it does, it regenerates very slowly. So by regularly burning the chaparral, fire managers had inadvertently rid the landscape of natural, fire-resistant species and let invasive, more flammable vegetation take its place [source: Oskin]. In this particular case, in other words, controlled burning was counterproductive.
There is no general rule for how (and whether) controlled burning is beneficial. It all depends on the region. Local species and weather determine what works best and where. Take, for instance, the computer modeling about carbon capture mentioned earlier. Those simulations were conducted in a northern Arizona ponderosa pine forest. The results don't necessarily apply elsewhere.
In fact, a forestry expert in Oregon doubts that a northeastern forest that's managed with controlled burning would hold more carbon than one that wasn't. While it seems that controlled burning carried out in southeastern woodland helps the atmosphere, the same cannot necessarily be said of other forests.
Nevertheless, controlled burns help the environment in other ways. By maintaining open canopies, fire can improve a forest's structure and variety, making it more resilient to climate change [source: Gearin]. Paradoxically, it seems we might be able to use this great, destructive force to mitigate the damage we've done to the ecosystem.
Author's Note: How Controlled Burns Work
Lighting a fire in my woodstove every winter morning is the closest I come to a controlled burn. A few weeks ago, the controls failed when we had a chimney fire. It's nerve-wracking enough to watch a stovepipe turn red with heat, but when the top of the chimney is shooting out flames, it's time to call 911. Fortunately, the fire burned itself out and all was well. But 20 minutes of semi-uncontrolled burning were more than enough for me to relearn respect for the power of fire.
More Great Links
- Choi, Charles. "Humans Used Fire 1 Million Years Ago." Discovery News. April 2, 2012. (April 21, 2016) http://news.discovery.com/history/archaeology/human-ancestor-fire-120402.htm
- Dickman, Kyle. "Will America's Worst Wildfire Happen in New Jersey?" Rolling Stone. April 20, 2016. http://www.rollingstone.com/culture/features/will-americas-worst-wildfire-disaster-happen-in-new-jersey-20160420
- Ellis, Erle C. et al. "Used Planet: A Global History." Proceedings of the National Academy of Sciences. Vol. 110, No. 20. Pages 7978-7985. April 29, 2013. (April 21, 2016) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3657770/
- Environmental Protection Agency. "Wildfires and Prescribed Burning." (April 19, 2016) https://www3.epa.gov/ttnchie1/ap42/ch13/final/c13s01.pdf
- Erickson, David. "Study Finds That Climate Change Is Increasing Length of Wildfire Seasons Across the Globe." Missoulian. July 18, 2015. (April 26, 2016) http://missoulian.com/news/local/study-finds-climate-change-is-increasing-length-of-wildfire-seasons/article_f702047f-6627-5745-93ea-1ac29b095123.html
- Gearin, Conor. "Controlled Fires Could Actually Save Forests and Fight Climate Change." Nova Next, PBS. Oct. 30, 2015. (April 19, 2016) http://www.pbs.org/wgbh/nova/next/earth/controlled-fires-could-actually-save-forests-and-fight-climate-change/
- Johnson, A. Sydney and Philip E. Hale. "The Historical Foundations of Prescribed Burning for Wildlife: a Southeastern Perspective." USDA Forest Service. (April 18, 2016) http://originwww.nrs.fs.fed.us/pubs/gtr/gtr_ne288/gtr_ne288_011.pdf
- Minnesota Department of Natural Resources. "The Benefits of Prescribed Burning on Private Land." 1994. (April 18, 2016) http://files.dnr.state.mn.us/assistance/backyard/privatelandhabitat/benefits_prescribed_burning.pdf
- Montiel, Cristina and Daniel Kraus (eds.). "Best Practices of Fire Use — Prescribed Burning and Suppression Fire Programmes in Selected Case-Study Regions in Europe." European Forest Institute. 2010. (April 18, 2016) https://www.ucm.es/data/cont/docs/530-2013-10-15-efi_rr2449.pdf
- National Park Service. "Giant Sequoias and Fire." (April 19, 2016) https://www.nps.gov/seki/learn/nature/fic_segi.htm
- Oskin, Becky. "Fighting Fires: You're Doing It Wrong." LiveScience. Jan. 14, 2013. (April 21, 2016) http://www.livescience.com/26257-fighting-chaparral-fires-myths-busted.html
- Ryan, Kevin C. et al. "Prescribed Fire in North American Forests and Woodlands: History, Current Practice, and Challenges." Frontiers in Ecology and the Environment. 2013. Vol. 11, Iss. 1. Pages e15-e24. (April 18, 2016) http://www.fs.fed.us/rm/pubs_other/rmrs_2013_ryan_k002.pdf
- Snowdon, Wallis. "Alberta Family Devastated by Wildfire Shares Survival Story." CBC News. April 20, 2016. (April 18, 2016) http://www.cbc.ca/news/canada/edmonton/alberta-family-devastated-by-wildfire-shares-survival-story-1.3545506
- Swain, Glenn. "Burning a Forest to Save It." The New York Times Blog. Sept. 26, 2012. (April 18, 2016) http://green.blogs.nytimes.com/2012/09/26/burning-a-forest-to-save-it/?_r=0
- Williams, Gerald W. "References on the American Indian Use of Fire in Ecosystems." USDA Forest Service. May 18, 2001. (April 18, 2016) http://www.wildlandfire.com/docs/biblio_indianfire.htm