Tamm review: The effects of prescribed fire on wildfire regimes and impacts: A framework for comparison

Prescribed fire can result in significant benefits to ecosystems and society. Examples include improved wildlifehabitat, enhanced biodiversity, reduced threat of destructive wildfire, and enhanced ecosystem resilience.Prescribed fire can also come with costs, such as reduced air quality and impacts to fire sensitive species. To planfor appropriate use of prescribed fire, managers need information on the tradeoffs between prescribed fire andwildfire regimes. In this study, we argue that information on tradeoffs should be presented at spatial andtemporal scales commensurate with the scales at which these processes occur and that simulation modelingexercises should include some realistic measure of wildfire probability. To that end, we synthesized availablescientific literature on relationships between prescribed fire and wildfire regimes, and their associated ecologicaland societal effects, focusing specifically on simulation modeling studies that consider wildfire probability andempirical and modeling studies that consider prescribed fire and wildfire regimes at spatial and temporal scalesbeyond individual events. Both empirical and modeling studies overwhelmingly show that increasing use ofprescribed fire can result in wildfire regimes of lower extent and intensity. In some studies, a consequenceassociated with increased use of prescribed fire is an increase in the total, cumulative amount of fire on alandscape over time. Presumably this has implications for emissions and ecosystem carbon, however, effects onecosystem carbon dynamics are much less clear as results vary considerably across studies. Results likely varybecause studies use various landscape models with different parameter settings for processes (e.g., vegetationsuccession) and use different methodologies, time frames, and fire management and climate change scenarios.Future syntheses and meta-analyses would benefit from researchers providing more comprehensive and transparentdocumentation of model parameters, assumptions, and limitations. The literature review also revealedthat studies on the implications of prescribed fire and wildfire regimes with regard to values other than carbonand emissions are scant and this represents a critical research need. Empirical studies are needed to calibrate andprovide magnitude of order comparisons with simulation models and address tradeoffs with respect to othervalues (e.g., wildland urban interface, wildlife habitat). Such studies should be conducted with consideration forour framework, which includes the implications of prescribed fire and wildfire across broad spatial and temporalscales.