Authored by W.M. Block; Published 2016
Prescribed fire is applied widely as a management tool in North America to meet various objectives such as reducing fuel loads and fuel continuity, returning fire to an ecosystem, enhancing wildlife habitats, improving forage, preparing seedbeds, improving watershed conditions, enhancing nutrient cycling, controlling exotic weeds, and enhancing resilience from climate change. Regardless of the particular objective, fire affects ecosystem structure, composition, and function in many ways.
We used a regional approach, focusing on selected vegetation types for our review (Figure 1). Included were southeastern pine (Pinus spp.) and mixed pineoak (Quercus spp.) forests, eastern coastal marshes, midwestern jack pine forests, sagebrush (Artemisia spp.) ecosystems of the interior West, mixed-severity forests of the northern Rocky Mountains, subalpine and montane forests of the Canadian Rockies, southwestern ponderosa pine forests, desert grasslands, and shortgrass steppe ecosystems. We structured each regional account by reviewing historical and current uses of fire, and then discussed fire effects on wildlife and the challenges of using prescribed fire in each system. Prescribed fire affects wildlife in various ways. Population responses by species can be positive, negative, or neutral, short-term or long-term, and they often vary across spatial scales. Whereas prescribed fire can create or maintain habitats for some species, it can also remove or alter conditions in ways that render it unsuitable for other species. Furthermore, a species may benefit from fire in one situation but not another. Given the variations in fire and in species responses, the only real generalization one can make is that exceptions occur. Fire does not occur uniformly across a landscape, instead manifesting as a heterogeneous mosaic that provides habitats for different species, thereby influencing wildlife diversity. Practitioners should try to emulate natural mosaic patterns by designing and implementing a set of prescriptions rather than applying one prescription across a landscape. Social issues, particularly those surrounding smoke and emissions, constrain where, when, and how managers can burn vegetation. Certainly, emissions standards enforced by state and federal environmental agencies limit windows of opportunity for burning. Smoke billowing into human communities is a health concern, especially for people with existing respiratory ailments. Many publics associate smoke with fire and conclude that fire is bad. Progress has been made in educating the public concerning benefits of prescribed fire to both reduce threats of wildfire to people and property and to maintain or enhance ecological communities, but much work remains.
In conclusion, benefits of prescribed fire far outweigh negative effects. The science of prescribed fire continues to provide better information and options for resource managers to incorporate into management plans. Prescribed fire should be applied within a structured adaptive management framework, which requires developing and implementing monitoring systems to evaluate the efficacy of specific fire prescriptions. Depending on monitoring results, prescriptions could be applied elsewhere or adjusted to meet management objectives. Either way, prescribed fire is an important resource management tool that can be effective at maintaining or enhancing habitats for many species of wildlife.