Stephens and colleagues (2012) examined the efficacy of fuel treatments in reducing susceptibility to uncharacteristically severe fires in seasonally dry US forests. They were overly optimistic in stating that the effects of thinning on wildlife have “few unintended consequences” with “very subtle effects or no measurable effects at all” and failed to recognize the ecological benefits of high-severity fires that are actually below historic levels.
Stephens and colleagues did not include studies documenting adverse effects of thinning on small mammal prey species for northern spotted owls (Strix occidentalis caurina; e.g., Meyer et al. 2005) or on rare species, such as black-backed woodpeckers (Picoides arcticus; Hutto 2008). Nor did they address “ecological trap” phenomena created by silvicultural activities without evolutionary precedent—a factor that can draw declining postfire specialists like olive-sided flycatchers (Contopus cooperi) into managed environments wherein they suffer poor nest success (Robertson and Hutto 2007).
Moreover, Stephens and colleagues did not fully represent the benefits of high-severity fire by limiting analysis to the earliest postfire period (0–4 years postfire), thus excluding the portions of the data sets that they used that show that more bird species increase than decrease in high-severity fire areas after several years. In addition, the impetus for thinning is overstated. Only one study from one region is cited to suggest that fire severity is increasing and that it should be mitigated via thinning, but the authors did not mention that current data show no increase in fire severity in many western US regions. Nor did Stephens and colleagues account for thinning's impacts on imperiled species dependent on high-severity fire that have already experienced a severe loss of suitable habitat from fire suppression, such as the buff-breasted flycatcher (Empidonax fulvifrons) in southwestern US forests (Conway and Kirkpatrick 2007).
There is an urgent need for scientists to report on the myriad ecosystem benefits of wildfires, including high-severity fires, and to effectively document the impacts of fuel treatments on wildlife, especially rare species, so that managers are fully aware of the tradeoffs involved.
