Fire Management Options Research Articles

Predicting sub‐continental fuel hazard under future climate and rising atmospheric CO2 concentration

Abstract Bushfire fuel hazard is determined by the type, amount, density and three‐dimensional distribution of plant biomass and litter. The fuel hazard represents a biological control on fire danger and may change in the future with plant growth patterns. Rising atmospheric CO2 concentration (Ca) stimulates plant productivity (‘fertilisation effect’) but also alters climate, leading to a ‘climatic effect’. Both effects have impacts on future vegetation and thus fuel hazard. Quantifying these effects is an important component of predicting future fire regimes and evaluating fire management options. Here, we combined a machine learning algorithm that incorporates the power of large fine spatial resolution (i.e. 90 m) datasets with a novel optimality model that accounts for the climatic and fertilisation effects on vegetation cover. We demonstrated the usefulness and practicality of this framework by predicting fuel hazard across the state of Victoria in Australia. We fitted and evaluated the models with long‐term (i.e. 20 years), ground‐based fuel observations. The models achieved strong agreement with observations across the fuel hazard range (accuracy >65%). We found fuel hazard increased more in dry environments due to future climate and Ca. The contribution of the ‘fertilisation effect’ to future fuel hazard varied spatially by up to 12%. The predictions of future fuel hazard are directly useful to inform fire mitigation policies and as a reference for climate model projections to account for fire impacts. Synthesis and applications: Climate change and rising Ca have profound impacts on vegetation and thus fuel load. Operational fire management and future fire risk forecasts will benefit from our realistic fuel load prediction framework that incorporates plant responses and fine soil and terrain attributes.

The influence of thinning and prescribed burning on future forest fires in fire-prone regions of Europe

Climate change is expected to increase fire risk in many forested regions, posing a potential threat to forest functioning (i.e. carbon pools and fluxes). At the same time, expansion of the wildland-urban interface threatens to bring more and more people, property, and infrastructure into contact with wildfire events. It is critical that fire be managed in a way that minimizes risk to human health and well-being and maintains forest climate change mitigation potential without affecting the important ecological role fire plays in many ecosystems. Dynamic global vegetation models (DGVMs) simulate processes over large geographic regions and long time periods and could provide information that supports fire and fuel management programs by assessing performance of such measures under different climate change scenarios in different regions. However, thus far DGVMs have not been put to this use. In this work, we introduce a novel prescribed burning (PB) module to the LPJ-GUESS DGVM. Focusing on two regions (Eastern Europe and the Iberian Peninsula), we compare the effectiveness of PB and mechanical thinning on various aspects of the fire regime under two climate change scenarios through the end of the 21st century. We find that PB and thinning, by reducing fuel load, reduce fireline intensity; this suggests that what wildfires do occur could be more easily controlled. While this would reduce risks to human health and well-being, PB comes with the tradeoff of increased fire emissions, which could contribute to respiratory problems. Mechanical thinning reduces fireline intensity by as much or more while also reducing emissions. While net primary production remained unaffected by fire management, cumulative net biome production until the end of the 21st century declined especially under the influence of thinning. While these results are based on stylized management treatments, this work shows the potential of DGVMs in exploring fire management options.

Towards a comprehensive wildfire management strategy for Mediterranean areas: Framework development and implementation in Catalonia, Spain

Southern European countries rely largely on fire suppression and ignition prevention to manage a growing wildfire problem. We explored a more wholistic, long-term approach based on priority maps for the implementation of diverse management options aimed at creating fire resilient landscapes, restoring cultural fire regimes, facilitating safe and efficient fire response, and creating fire-adapted communities. To illustrate this new comprehensive strategy for fire-prone Mediterranean areas, we developed and implemented the framework in Catalonia (northeastern Spain). We first used advanced simulation modeling methods to assess various wildfire exposure metrics across spatially changing fire-regime conditions, and these outputs were then combined with land use maps and historical fire occurrence data to prioritize different fuel and fire management options at the municipality level. Priority sites for fuel management programs concentrated in the central and northeastern high-hazard forestlands. The suitable areas for reintroducing fires in natural ecosystems located in scattered municipalities with ample lightning ignitions and minimal human presence. Priority areas for ignition prevention programs were mapped to populated coastal municipalities and main transportation corridors. Landscapes where fire suppression is the principal long-term strategy concentrated in agricultural plains with a high density of ignitions. Localized programs to build defensible space and improve self-protection on communities could be emphasized in the coastal wildland-urban interface and inner intermix areas from Barcelona and Gerona. We discuss how the results of this study can facilitate collaborative landscape planning and identify the constraints that prevent a longer term and more effective solution to better coexist with fire in southern European regions.

Estimating wildfire response costs in Alaska\u2019s changing climate

Climate change is altering wildfire activity across Alaska, with increased area burned projected for the future. Changes in wildfire are expected to affect the need for management and suppression resources; however, the potential economic implications of these needs have not been evaluated. We projected area burned and associated response costs to 2100 under relatively high and low climate forcing scenarios (representative concentration pathways (RCP) 8.5 and 4.5) using the Alaskan Frame-based Ecosystem Code (ALFRESCO) model. We calculated unique response costs for each of the four fire management options (FMOs) currently used in Alaska that vary in suppression level using federal cost data. Cumulative area burned between 2006 and 2100 across Alaska averaged 46.7M ha under five climate models for RCP8.5 and 42.1M ha for RCP4.5, with estimated cumulative response costs of $1.2–2.1B and $1.1–2.0B, respectively (3% discount). The largest response costs were incurred for the Full FMO, an area of high suppression priority, but where risks to human life and property are relatively low. Projected response costs across the century indicated that costs would be largest annually in the 2090 era (2080–2099) under RCP8.5, totaling $41.9–72.9M per year. For RCP4.5, the highest costs were projected for the 2070 era (2060–2079) and totaled $36.2–63.4M per year. The relative change in annual area burned showed larger increases for RCP8.5 than RCP4.5 across much of the state. The reported response costs are likely an underestimate and limited available data for state incurred costs suggests that realized costs could be ~68% higher. These findings indicate that climate change will have continued impacts on wildfire response costs across Alaska that vary among FMOs and global greenhouse gas emissions futures.

Getting Ahead of the Wildfire Problem: Quantifying and Mapping Management Challenges and Opportunities

Wildfire is a global phenomenon that plays a vital role in regulating and maintaining many natural and human-influenced ecosystems but that also poses considerable risks to human populations and infrastructure. Fire managers are charged with balancing the short-term protection of human assets sensitive to fire exposure against the potential long-term benefits that wildfires can provide to natural systems and wildlife populations. The compressed decision timeframes imposed on fire managers during an incident are often insufficient to fully assess a range of fire management options and their respective implications for public and fire responder safety, attainment of land and resource objectives, and future trajectories of hazard and risk. This paper reviews the role of GIS-based assessment and planning to support operational wildfire management decisions, with a focus on recent and emerging research that pre-identifies anthropogenic and biophysical landscape features that can be leveraged to increase the safety and effectiveness of wildfire management operations. We use a case study from the United States to illustrate the development and application of tools that draw from research generated by the global fire management community.

Climate and Fire Scenario Uncertainty Dominate the Evaluation of Options for Conserving the Great Desert Skink

AbstractFire regimes are predicted to change under climate change, with associated impacts on species and ecosystems. However, the magnitude and direction of regime changes are uncertain, as will be species’ responses. For many species, how they respond will determine their medium‐long‐term viability. We propagate fire regime and species’ response uncertainties through a 50‐year viability analysis of the great desert skink, Liopholis kintorei, in central Australia, characterizing fire regime change under three scenarios. Species’ response uncertainty was characterized with three competing models based on fire and habitat variables, fitted to 11 years of occupancy data. We evaluate fire management options for conserving the species, based on their robustness to uncertainty about fire and species’ response. Efforts to minimize the frequency and size of fires provides the most consistent improvements to species’ persistence. We show that disentangling important from unimportant uncertainties enables conservation managers to make more efficient, defensible decisions.

Climate change presents increased potential for very large fires in the contiguous United States

Very large fires (VLFs) have important implications for communities, ecosystems, air quality and fire suppression expenditures. VLFs over the contiguous US have been strongly linked with meteorological and climatological variability. Building on prior modelling of VLFs (>5000 ha), an ensemble of 17 global climate models were statistically downscaled over the US for climate experiments covering the historic and mid-21st-century periods to estimate potential changes in VLF occurrence arising from anthropogenic climate change. Increased VLF potential was projected across most historically fire-prone regions, with the largest absolute increase in the intermountain West and Northern California. Complementary to modelled increases in VLF potential were changes in the seasonality of atmospheric conditions conducive to VLFs, including an earlier onset across the southern US and more symmetric seasonal extension in the northern regions. These projections provide insights into regional and seasonal distribution of VLF potential under a changing climate, and serve as a basis for future strategic and tactical fire management options.

Multi-scale influence of vapor pressure deficit on fire ignition and spread in boreal forest ecosystems

Abstract. Climate-driven changes in the fire regime within boreal forest ecosystems are likely to have important effects on carbon cycling and species composition. In the context of improving fire management options and developing more realistic scenarios of future change, it is important to understand how meteorology regulates different aspects of fire dynamics, including ignition, daily fire spread, and cumulative annual burned area. Here we combined Moderate-Resolution Imaging Spectroradiometer (MODIS) active fires (MCD14ML), MODIS imagery (MOD13A1) and ancillary historic fire perimeter information to produce a data set of daily fire spread maps for Alaska during 2002–2011. This approach provided a spatial and temporally continuous representation of fire progression and a precise identification of ignition and extinction locations and dates for each wildfire. The fire-spread maps were analyzed with daily vapor pressure deficit (VPD) observations from the North American Regional Reanalysis (NARR) and lightning strikes from the Alaska Lightning Detection Network (ALDN). We found a significant relationship between daily VPD and likelihood that a lightning strike would develop into a fire ignition. In the first week after ignition, above average VPD increased the probability that fires would grow to large or very large sizes. Strong relationships also were identified between VPD and burned area at several levels of temporal and spatial aggregation. As a consequence of regional coherence in meteorology, ignition, daily fire spread, and fire extinction events were often synchronized across different fires in interior Alaska. At a regional scale, the sum of positive VPD anomalies during the fire season was positively correlated with annual burned area during the NARR era (1979–2011; R2 = 0.45). Some of the largest fires we mapped had slow initial growth, indicating opportunities may exist for suppression efforts to adaptively manage these forests for climate change. The results of our spatiotemporal analysis provide new information about temporal and spatial dynamics of wildfires and have implications for modeling the terrestrial carbon cycle.

Savanna burning, greenhouse gas emissions and indigenous livelihoods: Introducing the Tiwi Carbon Study

AbstractSavanna burning for greenhouse gas abatement presents an opportunity for remote Aboriginal communities of northern Australia to engage with the mainstream economy while fulfilling cultural obligations for land stewardship. The recently established Tiwi Carbon Study aims to identify the biophysical and economic potential of fire management for greenhouse gas abatement on the Tiwi Islands north of Darwin, as a basis for possible livelihood opportunities for the Aboriginal Tiwi people. Recent (2001–2010) fire history for the Tiwi Islands based on AVHRR satellite imagery shows that on average 35% (187 700 ha) of its savanna woodlands and open forests are burned every year, with 72% of burning occurring late in the dry season (August to November). Non‐CO2 greenhouse gas emissions from Tiwi fires average 68 000 t CO2‐e year−1 and we discuss scenarios for greenhouse gas abatement through management of these fires by Tiwi people, consistent with the savanna burning methodology approved under the Federal Government's Carbon Farming Initiative. Changed fire management scenarios produced emissions abatement of up to 46 000 t CO2‐e year−1, with highest savings under a change in both fire frequency and intensity. In addition to abatement of non‐CO2 emissions, fire management has the potential to alter rates of carbon sequestered in soil and vegetation. Current ecosystem C stocks (excluding roots) on the Tiwi Islands range from 60 to 160 t C ha−1. The Tiwi Carbon Study features a long‐term, landscape‐scale fire experiment for informing full carbon accounting in relation to different fire management options, and for understanding their implications for biodiversity. We discuss potential co‐benefits and trade‐offs of fire management for greenhouse gas emissions abatement in relation to biodiversity and Tiwi cultural requirements and livelihood aspirations.

What Is Limiting More Flexible Fire Management—Public or Agency Pressure?

Abstract Conventional wisdom within American federal fire management agencies suggests that external influence such as community or political pressure for aggressive suppression are key factors circumscribing the ability to execute less aggressive fire management strategies. Thus, a better understanding of external constraints on fire management options is essential. This entails validating or refuting the perceptions of fire managers about the relative constraints that external pressures place on their ability to implement more flexible fire management options. In the summer of 2008, our research team traveled to two fires—the Gap in California and Gunbarrel in Wyoming—each of which used a different strategy for managing the fire. At each site, we interviewed key agency individuals and asked them about internal and external factors that influenced their fire management decisions. We also interviewed community members to understand whether they sought to influence fire management. Internal factors included procedural requirements and agency beliefs and attitudes. External factors included political and community pressures from the public who are often perceived to demand an aggressive suppression response. This article details how these internal and external factors influence flexibility in fire management. Our findings did not wholly support conventional wisdom and suggest that internal pressures are as important as external pressure in shaping fire management strategy.

Fire and carbon dynamics under climate change in south-eastern Australia: insights from FullCAM and FIRESCAPE modelling

This study used simulation modelling to investigate fire and carbon dynamics for projected warmer and drier climates in the south-eastern Australian high country. A carbon accounting model FullCAM and the landscape fire regime simulator FIRESCAPE were combined and used to simulate several fire management options under three climate scenarios – the recent climate (1975–2005); a moderate climate projected for 2070 (B1); and a more extreme climate projected for 2070 (A1FI). For warmer and drier climates, model simulations predicted (i) an increase in fire incidence; (ii) larger areas burned; (iii) higher mean fire intensities; (iv) shorter fire cycle lengths; (v) a greater proportion of fires burning earlier in the fire season; (vi) a reduction in carbon stores; (vii) a reduction in carbon sequestration rates; and (viii) an increase in the proportion of stored carbon emitted to the atmosphere. Prescribed burning at historical or twice historical levels had no effect on fire or carbon dynamics. In contrast, increasing the initial attack success (a surrogate for suppression) partially offset the adverse effects of warmer and drier climates on fire activity, but not on carbon dynamics. For the south-eastern Australian high country, simulations indicated that fire and carbon dynamics are sensitive to climate change, with simulated fire management only being able to partially offset the adverse effects of warmer and drier climate.

Simulated response of conterminous United States ecosystems to climate change at different levels of fire suppression, CO 2 emission rate, and growth response to CO 2

A modeling experiment was designed to investigate the impact of fire management, CO 2 emission rate, and the growth response to CO 2 on the response of ecosystems in the conterminous United States to climate scenarios produced by three different General Circulation Models (GCMs) as simulated by the MC1 Dynamic General Vegetation Model (DGVM). Distinct regional trends in response to projected climatic change were evident across all combinations of the experimental factors. In the eastern half of the U.S., the average response to relatively large increases in temperature and decreases in precipitation was an 11% loss of total ecosystem carbon. In the West, the response to increases in precipitation and relatively small increases in temperature was a 5% increase in total carbon stocks. Simulated fire suppression reduced average carbon losses in the East to about 6%, and preserved forests which were largely converted to woodland and savanna in the absence of fire suppression. Across the west, unsuppressed fire maintained near constant carbon stocks despite increases in vegetation productivity. With fire suppression, western carbon stocks increased by 10% and most shrublands were converted to woodland or even forest. With a relatively high level of growth in response to CO 2, total ecosystem carbon pools at the end of the century were on average about 9–10% larger in both regions of the U.S. compared to a low CO 2 response. The western U.S. gained enough carbon to counter losses from unsuppressed fire only with the high CO 2 response, especially in conjunction with the higher CO 2 emission rate. In the eastern U.S., fire suppression was sufficient to produce a simulated carbon sink only with both the high CO 2 response and emission rate. Considerable uncertainty exists with respect to the impacts of global warming on the ecosystems of the conterminous U.S., some of which resides in the future trajectory of greenhouse gas emissions, in the direct response of vegetation to increasing CO 2, and in future tradeoffs among different fire management options, as illustrated in this study.

Wildfire policy and use of science in the context of a socio-ecological system on the Aegean Archipelago

Abstract This paper summarizes the results of a primarily qualitative (with certain quantitative elements) socio-ecological study on three Greek islands of the Aegean Archipelago to characterize fire science and policy at regional and local levels, and perceptions of fire risk. Among the most important factors influencing dynamics of fire regimes on the islands are changing land use patterns and practices, and changes in climate and fuel conditions. While use of scientific information is not widespread, there are individuals in all three islands who regularly consult scientific sources. Although fire policy is largely controlled at the national and European Union levels, local activity also occurs, most notably through the volunteer fire fighting organizations, interactions with local officials, and public education efforts. However, though seen as important, significant lack of financial support and resources exist to support prevention and pre-suppression programs. Prevention of fires on the islands, including the use of prescribed burning, is relatively inadequate, and while an intense interest in preventing the loss of communities and ecosystems is frequently encountered, public participation in fire prevention remains limited. The findings suggest that relying on local knowledge, in combination with fire managers’ decision-making abilities, could improve fire management options and reduce wildfire suppression costs and ecological disasters.

Local to global perspectives on forest and land fires in Southeast Asia

Forest and land fires are not new to the landscapes of Southeast Asia. Nevertheless, strikingly different perspectives persist about the significance of fires in the tropics to environmental changes and human well-being and consequently how they should be managed. Our synthesis of papers in this special issue suggests both trade-offs and complementarities in various policy responses with differing objectives. There are, however, at least three domains with high potential of meeting multiple objectives. First, is through identification, and improved management, of ecosystems vulnerable to fire under current and future climate. Agriculture, forestry and human settlements on peat land areas in Indonesia are candidates for such a focus. Second, is through building adaptive capacities to manage fire and related land and water resources. Investments in capacity at multiple levels are needed, but particularly at fairly local levels where stakeholders have strong incentives to manage fires appropriate to local contexts. Third, is through building awareness that fire management does not universally equate to fire suppression. Severe smoke haze episodes, for example, are also a result of timing of fires, and some fire-adapted ecosystems may depend on fire to persist. Finally, we emphasize that effective fire management is unlikely to be realized without greater engagement by research and policy with stakeholders in thoroughly exploring the full range of land and fire management options. Negotiation, compensation and trade-offs are probably inevitable.

Modeling Pinus strobus mortality following prescribed fire in Quetico Provincial Park, northwestern Ontario

In forest ecosystems where ecologically beneficial fire impacts are promoted through the use of prescribed fire, predictive models of fire effects, such as tree mortality, are essential for assessing the ecological consequences of fire management options. Impact of tree size, fire intensity, and fuel characteristics on postfire eastern white pine (Pinus strobus L.) mortality was evaluated 10 months following a prescribed fire in Quetico Provincial Park, northwestern Ontario. A logistic regression model was developed to predict white pine mortality following an intense surface fire (1200 kW/m). Overall fire-caused mortality was relatively low (17.0%). Probability of mortality increased with increasing height of stem blackening, a surrogate measure of fire intensity, and decreased with increasing tree diameter at 1.3 m (DBH). White pine with [Formula: see text]20 cm DBH were found to be highly resistant to intense surface fire. The model can be used to predict postfire mortality in white pine stands with a mixedwood understory in the Great Lakes – St. Lawrence forest region of Ontario.

Fire Management Options in Fynbos Mountain Catchment Areas

SYNOPSIS Four basic fire management options for fynbos in the mountain catchment areas of the Cape Province are outlined (scheduled block burning, two-phase block burning, adaptive interference fire management, natural fire zone management). Constraints on fire management affecting the choice of any particular option are discussed. The most important factors influencing fire management are management objectives, ecological considerations, fire hazard and invader plant control considerations. It is contended that a broader perspective on possible fire management options provide more scope to cope with prevailing constraints than restriction to the traditional scheduled block burning system.