My Turn: Logging industry study misleads on climate and forest fires
April 22, 2008
The recent My Turn guest column by Tom Bonnicksen in Sierra Sun (Reduce fire threat, aid fight against global warming April 2) is a wildly misleading attempt by the timber industry to promote increased logging of California’s forests under the guise of reducing wildland fires and mitigating climate change. Bonnicksen fails to mention that logging is one of the major contributors to greenhouse gas emissions (Schlesinger, Biogeochemistry: an analysis of global change, Academic Press, 1997). Also, Bonnicksen’s Ph.D. is in forest policy, not forest science. The computer model he created, which he discussed in his My Turn, has not been peer-reviewed or published in any scientific journal. Bonnicksen is not a working scientist but, rather, is a spokesperson for a timber industry group called the Forest Foundation. Predictably, his opinion piece does not cite any scientific studies to support his claims. Bonnicksen’s computer model is fatally flawed because it makes grossly inaccurate assumptions. For example, Bonnicksen’s model is based upon the assumption that no natural growth of forest will occur after a wildland fire. In fact, some of the most productive forest growth occurs after fire, including in high severity fire areas in which most or all of the trees were killed (Shatford and others 2007, Journal of Forestry, May 2007). Fire converts woody material on the forest floor from relatively unusable forms into highly useable nutrients, which aids forest productivity. The rapid forest growth following wildland fire sequesters huge amounts of the greenhouse gas carbon dioxide in the new post-fire tree growth. Whatever carbon emissions occur from combustion during wildland fire and subsequent decay of fire-killed trees is more than balanced by forest growth across the landscape over time. The California Air Resources Board’s data reveals that current emissions from forest fires in California are less than 1 percent of those from fossil fuel consumption in this state, and that carbon sequestration from forest growth far outweighs carbon emissions from fire. Bonnicksen’s model also incorrectly assumes that, when fire-killed trees fall and decay, essentially all of the carbon in the wood is emitted into the atmosphere. In reality, much of the carbon ends up in the soil (Schlesinger 1997, see above). Bonnicksen greatly exaggerates the percentage of trees killed by fire, and provides no source for his estimates. He assumes roughly 90 percent mortality of large trees. However, the Forest Service’s own data shows that, contrary to popular myth, low and moderate severity effects (where most large trees survive) dominate current wildland fires in the Sierra Nevada (Miller and Thode 2007, Remote Sensing of Environment, Vol. 109; Odion and Hanson 2008, Ecosystems, Vol. 11). Even high severity fire is reduced, relative to its historic extent (Hanson 2007, Ph.D. Dissertation, UC Davis; Nagel and Taylor 2005, Journal of the Torry Botanical Society, Vol. 132). Historic fire regimes in California’s forests included a mix of low, moderate, and high severity effects (Beatty and Taylor 2001, Journal of Biogeography, Vol. 28). In fact, native species have evolved with fire over millennia in state forests, and many depend upon post-fire habitat. Interestingly, some of the highest levels of native biodiversity among animals and higher plants are found in unlogged forested areas that have burned at high severity (Noss and others 2006, Frontiers in Ecology and Environment, Vol. 4). It’s important for people to know the facts about fire, ecosystems, and climate. Unfortunately, the timber industry is less interested in the truth than it is in serving its own economic goals. Chad Hanson is the director of the John Muir Project (www.johnmuirproject.org), based in Cedar Ridge outside of Grass Valley.