Fire is a fundamental driver of ecological processes that coevolves with biotic communities and that is changing under direct and indirect anthropogenic impacts (McLauchlan et al., 2020; Shuman et al., 2022; Turner et al., 2022). The interplay between fire and humans has been going on for hundreds of thousands of years (Roebroeks and Villa, 2011). This long history makes it impossible to separate anthropogenic effects from natural background fire regimes (Bowman et al., 2011). When and how did anthropogenic fires depart from the natural cycles of planet Earth? We have no clear answer. Nonetheless, the human populations are altering fire regimes worldwide, by clearing forests and shifting land use, dispersing plants, altering ignition patterns, and actively suppressing fires (Bowman et al., 2011; Parisien et al., 2016; McLauchlan et al. 2020), with important consequences for fire-adapted ecosystems and the species inhabiting them. Fire suppression and shifts in fire return intervals (FRIs) have caused habitat degradation (Van Lear et al., 2005), woody encroachment into grasslands (Twidwell et al., 2013), and decline or extinction of fauna populations (Woinarski et al., 2015). Model simulations have predicted that the complete exclusion of fire from Planet Earth would result in a global transfiguration of biomes (Bond et al., 2005).
Hence, to serve biological conservation objectives, natural resource managers employ prescribed fire, supplementing the modified wildfire regimes. Often, by applying prescribed fire, natural resource managers try to mimic as best as possible the natural conditions that were occurring before the human technologic eras (Frost, 1998; Conedera et al., 2009). However, although knowledge of historical fire regimes is important, understanding contemporary fire-biota interactions across trophic levels, functional groups, spatial scales, and management contexts is also critical (Freeman et al., 2017) for an effective fire management that accounts for the evolving feedbacks between ecosystems and fire regimes (i.e., pyrodiversity; Bowman et al., 2016). Overall, the concept of pyrodiversity, defined as variable fire regimes in relation to the spatial variability of trophic levels and ecological processes (Bowman et al., 2016), seems to be extensively supported across disciplines such as ecosystem ecology, forest management, and conservation biology (Martin and Sapsis, 1992; Williams and Baker, 2012; Kelly et al., 2012; Mason and Lashley, 2021).
Management of prescribed fire is complicated by the need to consider the protection of human life and infrastructure, and the provision of ecosystem services (Bowman et al., 2013). The presence of human infrastructure affects the ability of natural resource managers to achieve conservation objectives through fire management. For example, densely populated areas rarely support high pyrodiversity, largely because of fire suppression (Steel et al., 2021). Moreover, habitat loss and fragmentation may interact with fire regimes in ways that are not totally predictable, with the risk of even causing unintended local extinctions with fire management (Driscoll et al., 2021).
Since prescribed fire management is restricted by a combination of limited operational resources, environmental conditions, and competing ecological objectives, opportunities to perform a prescribed fire can be considered a “zero-sum game”: there are a finite number of burn days, and decisions on where and when to burn necessarily involve difficult tradeoffs. The problem becomes acute in large, complex landscapes that include wildland-urban interfaces (WUIs), where optimizing prescribed fire decision-making would substantially enhance efficiency, promote better resource management outcomes, and protect the health and safety of adjacent human populations.
Fire science as a field is challenged by rapidly changing fire regimes, climate change, and growing human populations in WUIs. A recent synthesis of these challenges (Shuman et al. 2022) identified a need to integrate across disciplines, co-produce knowledge, utilize big data, and develop models with human and natural dimensions. Spatial modeling using geographic information systems (GIS) offers a quantitative approach for resolving biological conservation and landscape management issues (Hiers et al., 2003; Kandel et al., 2015). It provides a mechanism by which spatially explicit quantitative and qualitative data can be integrated to analyze and model landscape level processes at different spatial scales. For example, GIS can be used to integrate multiple determinant factors affecting fire management across a landscape into a single spatially and temporally explicit management model that informs and drives management decisions. By displaying the different factors influencing fire management planning in a spatially explicit fashion, contrasting issues within the landscape can be modeled in their granularity by assigning numerical, standardized scores based on expert opinion and published research.
Fire-related decision-support tools should be employed to manage ecosystems that experience variation in fire regimes at large spatial scales. For example, wetlands of the Florida Everglades vary in hydrology (e.g., days of water inundation or hydroperiod, as well as flooding and drought cycles) and fire return intervals, and therefore need to be managed differently for short- and long-term hydroperiod wetlands (Lockwood et al. 2003). Further, the combined effects of fire and changing hydroperiod influence post-fire recovery and vegetation composition (Ruiz et al. 2013, Kominoski et al. 2022, Nocentini et al. 2024) and are therefore important for habitats structure. In 1958, after recognizing the role of fire in maintaining pine rocklands, Everglades National Park (ENP) ignited the first prescribed fire in National Park Service history (National Park Service, 2023). Since then, prescribed fire has been used as an important conservation tool for fire-prone biomes of ENP: marshes, prairies, and pine rocklands. Fire management planning in ENP is nonetheless a complex matter, as it must address a variety of competing ecological and logistical goals (National Park Service, 2015; Nocentini et al., 2021a). For example, the time window for carrying out a prescribed fire in certain areas of ENP is often constrained by the need to burn with the appropriate hydrologic conditions while also burning outside of the nesting season of endangered species. Although ENP fire management plans are carefully considered and built through expert opinion, which are also based on current conditions observed during helicopter surveys of the landscape, they are mostly based on qualitative rather than quantitative assessments.
Here, we developed a decision-support framework (Fig. 1) and a burn prioritization model that, through fine-scale spatial computations, supported diverse fire regimes across ENP wetland landscape, based on spatial variability of ecosystem types and species habitats, while satisfying the need to protect human life, cultural heritage, and infrastructure. Burn prioritization tools allow natural resource managers to compute FRIs (i.e., fire frequency), and to plan fire management in the medium to long term with high efficiency (Hiers et al., 2003). Fire frequency is particularly critical as it shapes vegetation structure and composition, and subsequently maintains faunal habitats (Griffiths et al., 2015).