How Protected Areas Help Scientists Better Understand Fire Regimes
Science & Research
April 2016 | Volume 22, Number 1
by SEAN A. PARKS
The Aldo Leopold Wilderness Research Institute (ALWRI) conducts science under three central themes: (1) science for wilderness, (2) wilderness for landscape sustainability, and (3) wilderness for science. Science for wilderness emphasizes that our work informs effective stewardship and management of wilderness. Wilderness for landscape sustainability aims to improve understanding of the roles of protected lands in maintaining the ecological, economic, and social integrity of larger landscapes. Wilderness for science recognizes that wilderness can serve as a laboratory and benchmark to understand the causes and consequences of environmental change in areas minimally confounded by human influences. The focus of this article is the last theme with a twist: wilderness for fire science (see Miller and Aplet 2015). ALWRI scientists partner with many organizations to conduct research on this theme, including The Wilderness Society, Canadian Forest Service, Joint Fire Science Program, University of Montana, Northern Rockies Fire Science Network, University of Idaho, and University of Massachusetts.
Wildland fire activity has been substantially reduced in many regions of the world due to human activities and infrastructure such as logging, roads, fire suppression, and altered land use. However, in the United States and else-where in the world, wildland fire was historically a natural ecological process that cycled nutrients, maintained landscape resilience, and provided suitable habitat for myriad species. In fact, many species in fire-prone landscapes evolved adaptive traits to cope with fire. Consequently, there is growing recognition that fire is not always “bad” or “catastrophic,” and in some regions of the world, that fire should be allowed to occur or should even be reintroduced. There is an urgent need to better understand fire regimes, and the best place to study the causes and consequences of fire in the absence of human-induced confounding factors is wilderness. That is where wilderness for fire science plays a role.
To better understand how the biophysical environment and fire exclusion influences fire regime characteristics in landscapes with low human influence, several scientific studies have been conducted within protected areas. Findings suggest that topography and vegetation plays a major role in influencing fire severity (Thompson et al. 2007; Kane et al. 2015) and that some wilderness landscapes in the western United States are more likely to be resilient to reintroduced fire because of the absence of previous logging (e.g., Larson et al. 2013). These unlogged wilderness landscapes can also provide valuable information on fire-induced tree mortality (Belote et al. 2015) and on historical fire interval, forest structure, and forest composition (Barth et al. 2015).
In protected areas that have allowed fire to play a more natural role (for example, the Selway-Bitterroot Wilderness and Aldo Leopold Wilderness in the United States), a natural experiment is unfolding that is allowing scientists to better understand the role of past fires in influencing subsequent fire behavior, size, and occurrence. Scientists are using observed fire patterns to evaluate the effectiveness and longevity of wildland fire to act as a fuel treatment and evaluate factors that maintain or increase resilience to future fire events. Collectively, these studies have concluded that previous fire does limit the occurrence, size, and severity of subsequent fire, but that the strength and longevity of this effect varies depending on the productivity and fire regime characteristics of each region (e.g., Collins et al. 2009; Parks et al. 2016). These studies also concluded that previous fire is less effective at regulating subsequent fire characteristics under extreme weather conditions (Parks et al. 2015). These studies complement and expand on previous studies that used simulation models to look at similar questions (e.g., Davis et al. 2010).
On a more regional level, recent studies conducted within the United States and internationally have shown that fire activity and climate are tightly linked in protected areas, but that this relationship weakens, or decouples, as landscapes become more human influenced (Archibald et al. 2010; Parks et al. 2014). As such, protected areas serve as a valuable benchmark that provides insight as to how fire naturally responds to climate and has allowed scientists to quantify how much fire “should” be expected within various climate domains. In fact, this reasoning has helped scientists identify where there has been more or less fire than the climate would dictate, not just within protected areas, but covering the western United States irrespective of protected area status (Parks et al. 2015). Evaluations of the relationship between fire and climate in protected areas may also provide insight into how climate change will influence fire regime characteristics.
The findings of these and other studies conducted within protected areas have relevance far beyond protected areas and are applicable to lands of all management designations. That is why this research is considered wilderness for science. However, it should not be under-emphasized that such studies are also highly relevant to wilderness steward-ship and management, and may also be couched as science for wilderness.
SEAN PARKS is a research ecologist at the Aldo Leopold Wilderness Research Institute, Missoula, MT; email: sean_ parks@fs.fed.us.
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References
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