Editor’s Note: The following is the second of three in a series of articles by Colorado State University’s Karissa Courtney covering important forest topics facing the United States. Part I delves into the intricacies of the Wildland Urban Interface (WUI) and looks at some recent very large fires in the West. In Part 2 (below), Courtney argues that Smokey the Bear has worked “too well” with recent forest fires increasing in intensity and severity. Part 3 (forthcoming) focuses on tree planting and thinning and how government agencies get projects like this done thanks to the National Environmental Policy Act…
Most people when asked, will acknowledge that fire doesn’t seem that great. It can destroy homes, kill people, create very bad air quality, and kill plants and animals. That all makes sense logically, but besides fires just being scary, where did this idea largely come from? Smokey Bear may be at fault here. The 1947 slogan of the strong, patriotic bear, “Only YOU Can Prevent Forest Fires!” (US Forest Service 2014) is one that is not easily forgotten, and one that implies that forest fires are bad. Smokey Bear was created in 1944, when the US Forest Service and Ad Council came up with the idea of a bear as the symbol for promoting forest fire prevention (US Forest Service 2014). While it has good intentions – don’t start unnecessary fires— it has large implications that fires are generally very bad. There are multiple ads that claim fires are a “waste” and that generally depict forest fires as only devastating and terrible. Other articles have criticized Smokey in a similar way, but the purpose here is to steer the conversation back toward what healthy fire looks like – and it’s different in all areas and forest types. Healthy fire is based on the historic range of variability, or what the frequency of fire was in the past in that area, of fire and its ecological significance prior to land-use changes with Euro-American settlement (Sherriff and Veblen 2007).
For a long time, and even still today depending what circles you reside in and where you live, fires are portrayed in a bad way, and often rightly so because of their destruction. It’s clear that Smokey Bear has had an effect on the American people – with skepticism of prescribed burning, a history of fire suppression, and bad depictions of fire in the media (think Bambi). After World War II, they even made the Smokey poster based on the Uncle Sam army recruiting poster. This made Smokey feel even more political and domineering than before – this was a war on fire that you could join in on and fight.
Even though the damage has already been done with Smokey Bear, it’s important to try to change the narrative. Sure, you need to follow fire restrictions/burn bans in the summer and properly put your cigarette out, but we also can point out why fires are actually good, and why more should be done in the WUI (read Part I). Fires are good disturbances for many different reasons. But first, what is meant by disturbance? A disturbance, as defined by Sousa (1984), is a “discrete, punctuated killing, displacement, or damaging of one or more individuals that creates an opportunity for new individuals to become established.” That being said, fires are disturbances that can have positive outcomes on the ecosystem. Fires can affect the carbon cycle, plant species composition, nutrient cycling, soil chemistry, and seed germination (Thonicke et al. 2001).
As you have likely noticed if you live in the western United States, wildfires have been increasing in number and magnitude. This is due to a number of reasons, not only “poor” forest management. Human-caused climate change, increased movement in to the WUI, and past forest management all have compounded, resulting in increased fire severity across the West (Rodman et al. 2019). Another issue surrounding fires in recent years is the fact that climate change is causing the fire season to be longer in the West. Based on federal wildland firefighting seasonal positions, the fire season used to begin around June and last through the end of September. We are now seeing fire seasons beginning in May and not finishing up until well into November. This also is an issue for fire-fighting manpower, as most seasonal federal positions end at the beginning of October even though fires may be raging on. This means that there are potentially less workers able to help cull these disturbances. This is an issue we are facing, but it’s still important to remember that fire is a natural, recurring phenomenon that forests have been accustomed to for thousands of years.
Each forest type and location likely have a slightly different fire regime (or generalization of fire history). For example, ponderosa pine (Pinus ponderosa) forests of western North America consist of recurrent, low-severity surface fires (Brown and Wu 2005). Ponderosa pine trees are well adapted to fire with thick bark that protects their inner structures from burning and dying, as well as high crowns that help reduce the likelihood of fatal crown fires (Brown and Wu 2005). Crown fires are fires that get into the top of the trees, which results in trees being more likely to completely burn and die. Crown fires are often associated with higher severity fires because ground/surface fires stay low and don’t have as much fuel to consume (think more branches, tree trunks, and needles or leaves).
As you have likely noticed if you live in the western United States, wildfires have been increasing in number and magnitude. This is due to a number of reasons, not only “poor” forest management. Human-caused climate change, increased movement in to the WUI, and past forest management all have compounded, resulting in increased fire severity across the West (Rodman et al. 2019). Another issue surrounding fires in recent years is the fact that climate change is causing the fire season to be longer in the West. Based on federal
In Colorado, there is a common belief that ponderosa pine forests historically experienced frequent, low-severity fires that kept woodlands open and clear (Sherriff and Veblen 2007) prior to fire suppression management. However, the lowest elevation of ponderosa pine forests of the Front Range historically experienced infrequent, high-severity fires. Sherriff and Veblen (2007) further state that the decline in fire occurrence in the past is due to suppression, fewer ignitions by humans (thanks to Smokey for this?), and fuel reductions. Additionally, the higher tree densities at higher elevations in the Front Range are actually thanks to 19th century severe fires, rather than a consequence of fire suppression (Sherriff and Veblen 2007). Some studies have even found there to be no evidence that higher forest protections are associated with more severe fires, which goes against popular belief (Bradley et al. 2016). This, of course, can currently only be applied to the areas in which the study was conducted. Therefore, thinning work to reduce the occurrence of large, severe wildfires may help in some areas, but might not be what the area had historically. This is something we will have to continue to weigh pros and cons for as more and more people are living and moving into the WUI –do we want an ecosystem in its historic range of variability, or do we want to prevent high-severity fires where people live?
Another example is the mixed-conifer forests in eastern Oregon and Washington. These forests historically had low-severity fires with patches of high-or mixed-severity (Heyerdahl et al. 2019). Looking at the western Cascade Range (from northern Washington to southern Oregon), dominated by Douglas-Fir (Pseudotsuga menziesii) stands, fire was widespread in the past, but has changed in frequency likely because of humans (Weisberg and Swanson 2003). One study (Weisberg and Swanson 2003) argues that the changing fire patterns are due to climate variability, changing human influences, patterns of fuel accumulation, or a combination of these. They also mentioned how climate factors can be important in initiating periods of widespread fire, but humans intensify it (Weisberg and Swanson 2003). Similarly, severe fires in the Pacific Northwest are associated with warm and dry conditions, which are increasing in frequency with a warming climate and can lead to a failure to have the same type of vegetation regrow (Halofsky et al. 2020). Not only does the warming of these areas increase the dry fuels, but it also contributes to increased stress on trees (van Mantgem et al. 2013). Trees can be more stressed due to increased water deficits (or increased drought stress), increased growth and reproduction of insects and pathogens, or both (van Mantgem et al. 2013).
So while Smokey has done his job (perhaps too well), it’s time to rethink his message and teach how fires are positive and necessary natural disturbances. We should therefore focus our attention, not on preventing and suppressing, but by educating the public, especially those living in the WUI about how to protect their homes, and maybe to not live directly in a forest where there is greater danger. Nature is a force not to be reckoned with, which we have definitely seen this past year.
Bradley, C.M., Hanson, C.T., and DellaSala, D.A. 2016. Does increased forest protection correspond to higher fire in frequent-fire forests of the western United States? Ecosphere 7(10): e01492.
Brown, P.M., and Wu, R. 2005. Climate and disturbance forcing of episodic recruitment in a southwestern ponderosa pine landscape. Ecology 86(11):3030-3038.
Covington, W.W. 2000. Helping western forests heal. Nature 408: 135-136.
Halofsky, J.E., Peterson, D.L., and Harvey, B.J. 2020. Changing wildfire, changing forests: the effects of climate change on fire regimes and vegetation in the Pacific Northwest, USA. Fire Ecology 16: 4.
Heyerdahl, E.K., Loehman, R.A., and Falk, D.A. 2019. A multi-century history of fire regimes along a transect of mixed-conifer forests in central Oregon, USA. Canadian Journal of Forest Research 49(1): 76-86.
Rodman, K.C., Veblen, T.T., Saraceni, S., and Chapman, T.B. 2019. Wildfire activity and land use drove 20th-century changes in forest cover in the Colorado front range. Ecosphere 10(2): e02594
Sherriff, R.L., and Veblen, T.T. 2007. A spatially-explicit reconstruction of historical fire occurrence in the ponderosa pine zone of the Colorado Front Range. Ecosystems 10(2): 311-323.
Sousa, W.P. 1984. The role of disturbance in natural communities. Annual review of ecology and systematics 15(1): 353-391.
Thonicke, K., Venesvsky, S., Sitch, S., and Cramer, W. 2001. The role of fire disturbance for global vegetation dynamics: coupling fire into a Dynamic Global Vegetation Model. Global Ecology an Biogeography 10: 661-677.
US Forest Service, Department of Agriculture, Office of Communication. 2014. “The story of Smokey Bear”. Available at https://www.fs.usda.gov/features/story-smokey-bear
Van Mantgem, P.J., Nesmith, J.C.B., Keifer, M., Knapp, E.E., Flint, A., and Flint L. 2013. Climate stress increases forest fire severity across the western United States. Ecology Letters 16: 1151-1156.
Weisberg, P.J., and Swanson, F.J. 2003. Regional synchroneity in fire regimes of western Oregon and Washington, USA. Forest Ecology and Management 172: 17-28.