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The recent worldwide increase of large, uncontrolled, and catastrophic wildfires events, caused important socio-economic issues and with considerable effects to the natural environment. Wildfires’ impacts on social-ecological systems derive from the complicated and multidimensional interconnected relationships between society and ecosystems. To enforce environmental and community resilience against wildfires, it is critical to holistically comprehend the local social-ecological systems. In this paper we present a holistic social-ecological systems resilience approach, built on performance-based wildfire engineering, that is envisioned to be a steppingstone towards the social-ecological resilience after a wildfire. To attain this objective, the performance assessment and design series of actions are disaggregated into explicit components of a rigorous mathematical framework. They are linked to a causal inference chain, providing an integrated picture, and enabling decision analysis to identify the optimal management strategies given a number of constraints. The proposed approach is proceeding from the total probability theorem and divides the risk assessment into single (underlying) parts, particularly: (1) hazard (wildfire) analysis, (2) damage analysis, (3) loss analysis, and social-ecological (4) impacts characterization, (5) interaction analysis, and (6) impacts analysis. A consistent probabilistic framework is proposed that explicitly considers and quantifies the inherent uncertainties for reliable wildfires performance resilient assessment. The suggested framework can be implemented by emergency agencies directly for performance assessment of society and ecosystems recovery after a wildfire, making more effective the emergency management and policy making.

Wildfire risk related to hazards on people and assets is expected to increase in the face of climate change, especially in fire-prone environments such as the Mediterranean Basin. Distinguishing rationalities, i.e., the complex profile of multi-thematic, wildfire-related perceptions that collectively characterize and quantify all of a society’s responses, its interrelations, and influence on its insights, are of primary importance to understand the degree of preparedness and the direction that wildfire management policies are moving. Greece is a country that suffered mega-wildfire events during the first years of the twenty-first century. This paper presents a scheme of advanced multivariate statistical procedures applied on standard social survey questionnaires to uncover different or similar rationalities between fire management services and the general public. Profession-centered versus message-oriented rationalities is defined. They differ mainly on the priorities attributed to strengthening personnel and equipment capacities versus the need for public education and awareness. Both are evaluated against the needs of long-term risk assessment and forest management policies in Greece. The main conclusion is that Greek society, although traumatized by recent fire disasters, is not yet prepared for long-term strategic forestry adaptation and planning.

Greece has an ever-increasing appeal for establishment of new and/or expansion of existing human settlements that in turn cause pressures on the natural environment, increasing the fire risk and resilience at a landscape level. A multitude of Mediterranean-type of ecosystems exist in the country, ranging from low shrubs and coniferous woodlands on coastal sites to high-elevation conifer and broadleaf forests. Fire plays a critical role on how these ecosystems were formed and function. Due to the topography, land uses, numerous islands, extensive coastlines and local microclimates, we find either broad zones with similar fire-related characteristics or enclaves where unique interactions with landscape fires prevail. We described the fuel and fire schemes in Greece as formed by different combinations of topography, weather, vegetation and human activity. A geographical context for this analysis was provided by examples of recent wildfires occurred in Greece during the 21st century, which re-shaped the landscape and affected in multiple ways the natural environment and human settlements from severe fire effects. In addition, we showed how these wildfires created crises that drove fire management policies; and we illustrated how fuels and wildfires should be managed based on their respective fire regimes and expected fire effects. Finally, we briefly reviewed future implications for wildfire management from the cumulative effects of climate change, urban sprawl and unmanaged forest growth.

The 2021fire season in Greece was disastrous in terms of area burned (140,000 ha), from six large-scale events (>10,000 ha) and one mega-fire in Evia Island (46,000 ha). These fires burned under extreme drought conditions and paradoxically, with moderate to low wind speeds, mostly inside low elevation conifer forests (Pinus halepensis) and shrublands. The concurrent burst and propagation of several large-scale events lead, once again, to the collapse of the firefighting mechanism, like what happened during the 2007 fire season when more than 260,000 ha burned. As a result, wildfires of 2021 were extinguished only when they reached the sea (Evia) or previously burned areas (western Attica), with firefighting forces completely unable to successfully contain them for weeks. The large number of reinforcements from other countries helped the government officials to understand and clarify (after debriefing) that with the current firefighting operational philosophy of the Greek Fire Service, it is impossible to contain large-scale wildfires. They detected several issues, including the total dependence on airborne firefighting means (Greece had during 2021 one of the largest aerial fleets in Europe), the inability of firefighters to operate inside forested areas, the prohibition of backfires, the slow creation rates, or complete lack, of vegetation clearings for creating new fuel breaks during firefighting, and the lack of appropriately previously treated areas. This sparked a debate among political parties and the society of what can Greece do from now on to prevent future mega-fires that can have devastating economic effects not only to the local population (e.g. northern Evia, an island that has based its local economy to forest products and recreational tourism), but also to the country’s economy (>4 billion euros in 2021). Another important issue is the environmental impact caused by the loss of forest carbon pools, soil loss and erosion, increased water runoff and degradation of the aesthetic quality, all having a long-lasting effect on the affected areas. The above lead the Greek Government to take a series of measures that were proposed, including legislation changes, administrative organization reforms and adaptation of firefighting operational tactics. A breakthrough is considered the re-creation of six special forest fire operation crews (a total of 500 people) following the standards of the US smokejumpers or hotshots’ crews. These crews are foreseen to be allowed to use backfires, after a necessary planned legislation reform. Another important legislation change was the simplification of bureaucracy that will enable landowners outside city limits to easily perform mild fuel reduction operations inside their property, currently illegal without permission. Despite these changes, an important component of improved fire risk governance is still missing. Fuel reduction is applied at the wrong scale, with inappropriate treatment methods, without proper planning and measurable outcomes and to landscape parts that can hardly influence fire propagation and intensity. In this work, we provide the context and a set of proposals and measures for fuel management that we believe are missing and if applied, can enhance prevention and improve the firefighting effectiveness, considering ecological, economic and operational issues.

This research shows the potential use of cross-boundary fire modeling systems at the pan-European level. Despite the growing interest in building fire-resilient cultural landscapes, European Union (EU) level efforts have been reactive and focused on early detection, fire propagation monitoring, and perimeter mapping rather than predicting where the disaster can potentially occur to develop a comprehensive wildfire management strategy. We propose a modeling system that integrates wildfire occurrence models and observed fire-weather scenarios with a fire spread model to generate the probabilistic risk components, i.e., wildfire likelihood and hazard estimates. We selected four NUTS-2 level administrative division pilot sites from different fire-prone countries to implement the modeling system. The European-level pyromes were first delineated based on ecoregions and historical wildfire activity. We then generated human and lightning wildfire occurrence models to display the ignition points. Remote sensing products were used to derive fire spread modeling spatial input data such as surface fuels and canopy metrics. Global atmospheric products were used to calculate the fuel moisture content with physical models and determine the most frequent wind scenarios for each pyrome. We then used the Minimum Travel Time algorithm to model the fire footprints that correspond to 10,000 years or synthetic iterations. This modeling approach accounted for the spatial variation of ignition locations and the changing weather conditions across the different pyromes within each pilot site. The modeling results include the annual burn probability and fire intensity rasters, and fire perimeter vector outputs. Modeled burn patterns showed a close agreement with observed fire size distributions. We compared this modeling system with previous works to explain why stochastic fire modeling is essential to assess wildfire exposure of natural values at risk and human communities. Our results may help predict future catastrophic fires and provide quantitative estimates to identify high-priority management areas within vast regions. The probabilistic predictions generated in this work represent the foundation for developing long-term adaptation strategies to better coexist with fire. This work is also a demonstration of how this modeling system is replicable in any European country.

Federal land managers in the US can be informed with quantitative assessments of the social conditions of the populations affected by wildfires originating on their administered lands in order to incorporate and adapt their management strategy to achieve a more targeted prioritization of community wildfire protection investments. In addition, these assessments are valuable to socially vulnerable communities for quantifying their exposure to wildfires originating on adjacent land tenures. We assessed fire transmission patterns using fire behavior simulations to understand spatial variations across three diverse study areas (North-central Washington; Central California; and Northern New Mexico) to understand how different land tenures affect highly socially vulnerable populated places. Transboundary wildfire structure exposure was related to populations with limited adaptive capacity to absorb, recover and modify exposure to wildfires, estimated with the Social Vulnerability Index using US Census unit data (block groups). We found geographic heterogeneity in terms of land tenure composition and estimated fire exposure. Although high social vulnerability block groups covered small areas, they had high population and structure density and were disproportionately exposed per area burned by fire. Structure exposure originated primarily from three key land tenures (wildland-urban interface, private lands and national forests). Federal lands proportionately exposed, on an area basis, populated places with high social vulnerability, with fires ignited on Forest Service administered lands mostly affecting north-central Washington and northern New Mexico communities.

We report a fine-scale assessment of cross-boundary wildfire events for the western US. We used simulation modeling to quantify the extent of fire exchange among major federal, state, and private land tenures and mapped locations where fire ignitions can potentially affect populated places. We examined how parcel size affects wildfire transmission and partitioned the relative amounts of transmitted fire between human and natural ignitions. We estimated that 85 % of the total predicted wildfire activity, as measured by area burned, originates from four land tenures (Forest Service, Bureau of Land Management, private, and state lands) and 63 % of the total amount results from natural versus human ignitions. On average, one-third of the area burned by predicted wildfires was nonlocal, meaning that the source ignition was on a different land tenure. Land tenures with smaller parcels tended to receive more incoming fire on a proportional basis, while the largest fires were generated from ignitions in national parks, national forests, and public and tribal lands. Among the 11 western states, the amount and pattern of cross-boundary fire varied substantially in terms of which land tenures were mostly exposed, by whom, and to what extent. We also found spatial variability in terms of community exposure among states, and more than half of the predicted structure exposure was caused by ignitions on private lands or within the wildland–urban interface areas. This study addressed gaps in existing wildfire risk assessments that do not explicitly consider cross-boundary fire transmission and do not identify the source of fire. The results can be used by state, federal, and local fire planning organizations to help improve risk mitigation programs.

US public land management agencies are faced with multiple, often conflicting objectives to meet management targets and produce a wide range of ecosystem services expected from public lands. One example is managing the growing wildfire risk to human and ecological values while meeting programmatic harvest targets for economic outputs mandated in agency budgets. Studies examining strategic management tradeoffs on federal lands and program efficiencies are rare. In this study we used the 79 western US national forests to examine tradeoffs between forest management scenarios targeting wildfire risk to the wildland urban interface (WUI) and those meeting agency convertible volume production targets. We quantified production frontiers to measure how the efficiency of meeting harvest volume targets is affected by prioritizing treatments to areas that transmit fire to the WUI. The results showed strong tradeoffs and scale effects on production frontiers, and more importantly substantial variation among planning areas and national forests. Prioritizing treatments to reduce fire transmission to the WUI resulted in an average harvest volume reduction of about 248 m3 per ha treated. The analysis also identified opportunities where both management objectives can be achieved. This work represents the first large-scale tradeoff analysis for key management goals in forest and fuel management programs on national forests.

Risk management typologies and their resulting archetypes can structure the many social and biophysical drivers of community wildfire risk into a set number of strategies to build community resilience. Existing typologies omit key factors that determine the scale and mechanism by which exposure from large wildfires occur. These factors are particularly important for land managing agencies like the US Forest Service, which must weigh community wildfire exposure against other management priorities. We analyze community wildfire exposure from national forests by associating conditions that affect exposure in the areas where wildfires ignite to conditions where exposure likely occurs. Linking source and exposure areas defines the scale at which cross-boundary exposure from large wildfires occurs and the scale at which mitigation actions need to be planned. We find that the vast majority of wildfire exposure from national forests is concentrated among a fraction of communities that are geographically clustered in discrete pockets. Among these communities, exposure varies primarily based on development patterns and vegetation gradients and secondarily based on social and ecological management constraints. We describe five community exposure archetypes along with their associated risk mitigation strategies. Only some archetypes have conditions that support hazardous fuels programs. Others have conditions where managing community exposure through vegetation management is unlikely to suffice. These archetypes reflect the diversity of development patterns, vegetation types, associated fuels, and management constraints that exist in the western US and provide a framework to guide public investments that improve management of wildfire risk within threatened communities and on the public lands that transmit fires to them.

Predicting the efficacy of fuel treatments aimed at reducing high severity fire in dry-mixed conifer forests in the western US is a challenging problem that has been addressed in a variety of ways using both field observations and wildfire simulation models. One way to describe the efficacy of fuel treatments is to quantify how often wildfires are expected to intersect areas prioritized for treatment. In real landscapes treatments are static, restricted to a small portion of the landscape and against a background of stochastic fire and dynamic vegetation, thus the likelihood of fire encountering a treatment during the period treatments remain effective is small. In this paper we simulate a wide range of different treatment prioritization schemes using the forest landscape simulation model Envision to examine 50 years of fire-treatment interactions and forest succession. We first reviewed 47 fuel management projects in Oregon, USA to build prioritization schemes that addressed different fuel management objectives. We then simulated different priority schemes in the 18 planning areas of the Deschutes National Forest in central Oregon and measured potential fire-treatment interactions over time. Simulated annual area burned was used to calculate the success odds for each priority scheme and planning area. Out of the ten metrics considered only three had higher success odds than a random prioritization of planning areas. Spatial allocation of projects based on burn probability and transmitted wildfire had the highest success odds among the tested metrics. However, success odds declined sharply as desired success levels increased suggesting that fuel management goals need to be tempered to consider the stochastic nature of wildfire. Meeting long-term multiple management goals over time can benefit from consideration of short- and long-term tradeoffs from different treatment prioritization schemes. Our work contributes towards a better framing of both management and public expectations regarding the performance of fuel treatments programs.

Managing forests has been demonstrated to be an efficient strategy for fragmenting fuels and for reducing fire spread rates and severity. However, large-scale analyses to examine operational aspects of implementing different forest management scenarios to meet fire governance objectives are nonexistent for many Mediterranean countries. In this study we described an optimization framework to build forest management scenarios that leverages fire simulation, forest management, and tradeoff analyses for forest areas in Macedonia, Greece. We demonstrated the framework to evaluate five forest management priorities aimed at (1) protection of developed areas, (2) optimized commercial timber harvests, (3) protection of ecosystem services, (4) fire resilience, and (5) reducing suppression difficulty. Results revealed that by managing approximately 33,000 ha across all lands in different allocations of 100 projects, the area that accounted for 16% of the wildfire exposure to developed areas was treated while harvesting 2.5% of total wood volume. The treatments also reduced fuels on the area that are responsible for 3% of the potential fire impacts to sites with important ecosystem services, while suppression difficulty and wildfire transmission to protected areas attainment was 4.5% and 16%, respectively. We also tested the performance of multiple forest district management priorities when applying a proposed four-year fuel treatment plan that targeted achieving high levels of attainment by treating less area but strategically selected lands. Sharp management tradeoffs were observed among all management priorities, especially for harvest production compared with suppression difficulty, the protection of developed areas, and wildfire exposure to protected areas.

Adapting to the growing frequency of catastrophic wildfires in Greece and mitigating their effects is a complex socio-ecological problem. We used an online survey to query more than 100 engaged stakeholders who can potentially influence possible legislation and fire management organizational reform, emphasizing civil protection agencies and research entities. We focused the questionnaire on the importance of different wildfire effects to understand which were considered negative or unacceptable, indifferent, or positive. For fire prevention, we examined the range of acceptance and views on fuel management and fire use activities that are limited in extent or not allowed in Greece. We also examined the beliefs regarding ignition causes and responsibility, in addition to how different policies might reduce wildfire-related problems. The results revealed an emphasis on reforming wildfire management policies to deal with the way society and agencies function and interact, and mitigate the influence of climate change in wildfire frequency and behavior. In addition, respondents had a negative stance towards allowing wildfires to burn for resource objectives and a strong belief that arsonists are behind most ignitions. They also believe the lack of a national cadaster system is a major source of wildfire-related problems. The results indicate little support for fuel treatments, but increased acceptance for the legalization of fire use during firefighting (backfires). This study summarizes current wildfire perceptions in Greece and identifies opportunities and barriers to changes in wildfire governance to improve risk management programs and guide post-fire management and mitigation.

In this study, we share an approach to locate and map forest management units with high accuracy and with relatively rapid turnaround. Our study area consists of private, state, and federal land holdings that cover four counties in North-Central Washington, USA (Kittitas, Okanogan, Chelan and Douglas). This area has a rich history of landscape change caused by frequent wildfires, insect attacks, disease outbreaks, and forest management practices, which is only partially documented across ownerships in an inconsistent fashion. To consistently quantify forest management activities for the entire study area, we leveraged Sentinel-2 satellite imagery, LANDFIRE existing vegetation types and disturbances, monitoring trends in burn severity fire perimeters, and Landsat 8 Burned Area products. Within our methodology, Sentinel-2 images were collected and transformed to orthogonal land cover change difference and ratio metrics using principal component analyses. In addition, the Normalized Difference Vegetation Index and the Relativized Burn Ratio index were estimated. These variables were used as predictors in Random Forests machine learning classification models. Known locations of forest treatment units were used to create samples to train the Random Forests models to estimate where changes in forest structure occurred between the years of 2016 and 2019. We visually inspected each derived polygon to manually assign one treatment class, either clearcut or thinning. Landsat 8 Burned Area products were used to derive prescribed fire units for the same period. The bulk of analyses were performed using the RMRS Raster Utility toolbar that facilitated spatial, statistical, and machine learning tools, while significantly reducing the required processing time and storage space associated with analyzing these large datasets. The results were combined with existing LANDFIRE vegetation disturbance and forest treatment data to create a 21-year dataset (1999&ndash, 2019) for the study area.

We assessed transboundary wildfire exposure among federal, state, and private lands and 447 communities in the state of Arizona, southwestern United States. The study quantified the relative magnitude of transboundary (incoming, outgoing) versus nontransboundary (i.e., self-burning) wildfire exposure based on land tenure or community of the simulated ignition and the resulting fire perimeter. We developed and described several new metrics to quantify and map transboundary exposure. We found that incoming transboundary fire accounted for 37% of the total area burned on large parcels of federal and state lands, whereas 63% of the area burned was burned by ignitions within the parcel. However, substantial parcel to parcel variation was observed for all land tenures for all metrics. We found that incoming transboundary fire accounted for 66% of the total area burned within communities versus 34% of the area burned by self-burning ignitions. Of the total area burned within communities, private lands contributed the largest proportion (36.7%), followed by national forests (19.5%), and state lands (15.4%). On average seven land tenures contributed wildfire to individual communities. Annual wildfire exposure to structures was highest for wildfires ignited on state and national forest land, followed by tribal, private, and BLM. We mapped community firesheds, that is, the area where ignitions can spawn fires that can burn into communities, and estimated that they covered 7.7 million ha, or 26% of the state of Arizona. Our methods address gaps in existing wildfire risk assessments, and their implementation can help reduce fragmentation in governance systems and inefficiencies in risk planning.

Social media is rapidly emerging as a potential resource of information capable to support natural disasters management. Despite the growing research interest focused on using social media during natural disasters, many challenges may arise on how to handle the ‘big data’ problem: huge amounts of geo-social data are available, in different formats and varying quality that must be processed quickly. This article presents a state-of-the-art approach towards the enhancement of decision support tools for natural disaster management with information from the Twitter social network. The novelty of the approach lies in the integration of Geographic Information Systems (GIS) modeling outputs with real-time information from Twitter. A first prototype has been implemented that integrates geo-referenced Twitter messages into a Web GIS for wildfire risk management and real-time earthquake monitoring. Following a highly scalable architecture that relies on big data components, the proposed methodology can be applied in different geographical areas, different types of social media and a variety of natural disasters. The article aims at highlighting the role of social big data, towards a more sophisticated transfer of knowledge among civil protection agencies, emergency response crews and affected population.

We report a fine scale assessment of cross-boundary wildfire events for the western US. We used simulation modeling to quantify the extent of fire exchange among major federal, state, and private land tenures and mapped locations where fire ignitions can potentially affect populated places. We examined how parcel size effects the wildfire transmission and partitioned the relative amounts of transmitted fire between human and natural ignitions. We estimated that almost 90 % of the total predicted wildfire activity as measured by area burned originates from four land tenures (Forest Service, Bureau of Land Management, private and State lands) and 63 % of the total amount results from natural versus human ignitions. On average, one third of the area burned by predicted wildfires was non-local, meaning that the source ignition was on a different land tenure. Land tenures with smaller parcels tended to receive more incoming fire on a proportional basis, while the largest fires were generated from ignitions in national parks, national forests, public and tribal lands. Among the 11 western States, the amount and pattern of cross-boundary fire varied substantially in terms of which land tenures were mostly exposed, by whom and to what fire sizes. We also found spatial variability in terms of community exposure among States, and more than half of the predicted structure exposure was caused by ignitions on private lands or within the wildland-urban interface areas. This study addressed gaps in existing wildfire risk assessments, that do not explicitly consider cross-boundary fire transmission and do not identify the sources of fire. The results can be used by State, Federal, and local fire planning organizations to help improve risk mitigation programs.

The development of comprehensive fire management and risk assessment strategies is of prominent concern in Southern Europe, due to the expanding scale of wildfire risk. In this work, we applied simulation modeling to analyze fine-scale (100-m resolution) wildfire exposure and risk transmission in the 24,000 km2 island of Sardinia (Italy). Sardinia contains a variety of ecological, cultural, anthropic and touristic resources that each summer are threatened by wildfires, and represents well the Mediterranean Basin environments and conditions. Wildfire simulations based on the minimum travel time algorithm were used to characterize wildfire exposure and risk transmission in terms of annual burn probability, flame length, structures exposed and type and amount of transmission. We focused on the historical conditions associated with large (>50 ha) and very large (>200 ha) wildfires that occurred in Sardinia in the period 1998–2016, and combined outputs from wildfire simulation modeling with land uses, building footprint locations, weather, and historical ignition data. The outputs were summarized for weather zones, main wind scenarios and land uses. Our study characterized spatial variations in wildfire spread, exposure and risk transmission among and within weather zones and the main winds associated with large events. This work provides a novel quantitative approach to inform wildfire risk management and planning in Mediterranean areas. The proposed methodology can serve as reference for wildfire risk assessment and can be replicated elsewhere. Findings can be used to better understand the spatial dynamics and patterns of wildfire risk and evaluate expected wildfire behavior or transmission potential in Sardinia and neighboring regions.

A solution to the growing problem of catastrophic wildfires in Greece will require a more holistic fuel management strategy that focuses more broadly on landscape fire behavior and risk in relation to suppression tactics and ignition prevention. Current fire protection planning is either non-existent or narrowly focused on reducing fuels in proximity to roads and communities where ignitions are most likely. A more effective strategy would expand the treatment footprint to landscape scales to reduce fire intensity and increase the likelihood of safe and efficient suppression activities. However, expanding fuels treatment programs on Greek landscapes that are highly fragmented in terms of land use and vegetation requires: (1) a better understanding of how diverse land cover types contribute to fire spread and intensity, and (2) case studies, both simulated and empirical, that demonstrate how landscape fuel management strategies can achieve desired outcomes in terms of fire behavior. In this study, we used Lesvos Island, Greece as a study area to characterize how different land cover types and land uses contribute to fire exposure and used wildfire simulation methods to understand how fire spreads among parcels of forests, developed areas, and other land cover types (shrublands, agricultural areas, and grasslands) as a way to identify fire source&ndash, sink relationships. We then simulated a spatially coordinated fuel management program that targeted the fire prone conifer forests that generally burn under the highest intensity. The treatment effects were measured in terms of post-treatment fire behavior and transmission. The results demonstrated an optimized method for fuel management planning that accounts for the connectivity of wildfire among different land types. The results also identified the scale of risk and the limitations of relying on small scattered fuel treatment units to manage long-term wildfire risk.

In this report we provide a framework for assessing cross-boundary wildfire exposure and a case study application in the western U.S. The case study provides detailed mapping and tabular decision support materials for prioritizing fuel management investments aimed at reducing wildfire exposure to communities located proximal to national forests. The work was motivated by a number of factors, including a request from U.S. Department of Agriculture Undersecretary James Hubbard (Natural Resources and Environment) to assess community wildfire risk specifically from Forest Service lands, language in the 2018 omnibus bill (Public Law 115-141) calling for a national assessment of wildfire risk to communities, and newer shared stewardship initiatives (Clavet 2018). We used national FSim simulation outputs to (1) estimate cross-boundary wildfire among major land types (Federal, State, private); (2) quantify structure exposure to all western communities; (3) map sources of community wildfire exposure (firesheds); (4) characterize firesheds in terms of management opportunity and fuels; and (5) prioritize communities based on integration of exposure and fireshed characteristics. The study revealed that 1,812 communities in the western U.S. could potentially be significantly impacted by future wildfires (more than 1 structure per year on average). Ignitions on national forest lands will most likely affect 516 of these 1,812 communities (more than one structure per year on average). Of the total exposure, ignitions on national forest lands will expose an estimated 4,000 structures (21 percent of total) in the western U.S. per year on average. Due to administrative restrictions on national forest lands, only about half of the total exposure from national forest lands (2,200 structures) originates on lands where mechanical treatments and prescribed fire are either allowed or ecologically appropriate. The framework can guide future efforts aimed at quantifying community and other cross-boundary exposure situations, and the outputs can be used to help identify shared stewardship projects, and prioritize fuel and other management activities within public land management agencies.

We describe a Web-GIS wildfire prevention and management platform (AEGIS) developed as an integrated and easy-to-use decision support tool to manage wildland fire hazards in Greece (http://aegis.aegean.gr). The AEGIS platform assists with early fire warning, fire planning, fire control and coordination of firefighting forces by providing online access to information that is essential for wildfire management. The system uses a number of spatial and non-spatial data sources to support key system functionalities. Land use/land cover maps were produced by combining field inventory data with high-resolution multispectral satellite images (RapidEye). These data support wildfire simulation tools that allow the users to examine potential fire behavior and hazard with the Minimum Travel Time fire spread algorithm. End-users provide a minimum number of inputs such as fire duration, ignition point and weather information to conduct a fire simulation. AEGIS offers three types of simulations, i.e., single-fire propagation, point-scale calculation of potential fire behavior, and burn probability analysis, similar to the FlamMap fire behavior modeling software. Artificial neural networks (ANNs) were utilized for wildfire ignition risk assessment based on various parameters, training methods, activation functions, pre-processing methods and network structures. The combination of ANNs and expected burned area maps are used to generate integrated output map of fire hazard prediction. The system also incorporates weather information obtained from remote automatic weather stations and weather forecast maps. The system and associated computation algorithms leverage parallel processing techniques (i.e., High Performance Computing and Cloud Computing) that ensure computational power required for real-time application. All AEGIS functionalities are accessible to authorized end-users through a web-based graphical user interface. An innovative smartphone application, AEGIS App, also provides mobile access to the web-based version of the system.

© 2019 by the Ecological Society of America Fire, a frequent disturbance in the Mediterranean, affects pollinator communities. We explored the response of major pollinator guilds to fire severity, across a fire-severity gradient at different spatial scales. We show that the abundance of all pollinator groups responded to fire severity, and that bees and beetles showed in addition a significant species-diversity response. Bees, sawflies, and wasps responded to fire severity at relatively small spatial scales (250–300 m), whereas flies and beetles responded at larger spatial scales. The response of bees, sawflies, and wasps was unimodal, as predicted by the intermediate disturbance hypothesis, whereas flies and beetles showed a negative response. A possible explanation is that the observed patterns (spatial scale and type of response) are driven by taxa-specific ecological and life-history traits, such as nesting preference and body size, as well as the availability of resources in the postfire landscape. Our observational study provides an insight into the effect of fire severity on pollinators. However, future research exploring the explicit link between the pre- and postfire landscape structure and pollinator traits and responses is required for further establishment and understanding of cause–effect relationships.

We assessed transboundary wildfire exposure among federal, state, and private lands and 447 communities in the state of Arizona, southwestern United States. The study quantified the relative magnitude of transboundary (incoming, outgoing) versus nontransboundary (i.e., self-burning) wildfire exposure based on land tenure or community of the simulated ignition and the resulting fire perimeter. We developed and described several new metrics to quantify and map transboundary exposure. We found that incoming transboundary fire accounted for 37% of the total area burned on large parcels of federal and state lands, whereas 63% of the area burned was burned by ignitions within the parcel. However, substantial parcel to parcel variation was observed for all land tenures for all metrics. We found that incoming transboundary fire accounted for 66% of the total area burned within communities versus 34% of the area burned by self-burning ignitions. Of the total area burned within communities, private lands contributed the largest proportion (36.7%), followed by national forests (19.5%), and state lands (15.4%). On average seven land tenures contributed wildfire to individual communities. Annual wildfire exposure to structures was highest for wildfires ignited on state and national forest land, followed by tribal, private, and BLM. We mapped community firesheds, that is, the area where ignitions can spawn fires that can burn into communities, and estimated that they covered 7.7 million ha, or 26% of the state of Arizona. Our methods address gaps in existing wildfire risk assessments, and their implementation can help reduce fragmentation in governance systems and inefficiencies in risk planning.

Predicting wildfire disasters presents a major challenge to the field of risk science, especially when fires propagate long distances through diverse fuel types and complex terrain. A good example is in the western US where large tracts of public lands routinely experience large fires that spread from remote wildlands into developed areas and cause structure loss and fatalities. In this paper we provide the first comprehensive assessment of where public wildlands potentially contribute wildfire exposure to communities in the 11 western US states. We used simulation modeling to map and characterize the composition of the source landscapes (firesheds) and recipient communities in terms of fuels, fire behavior and forest management suitability. The information was used to build a prototype investment prioritization framework that targets highly exposed communities where forest and fuel management activities are feasible. We found that simulated wildfires ignited on national forests can potentially affect about half of the communities in the western US (2560 out of 5118), with 90% of exposure affecting the top 20% of the communities (n = 516). Firesheds within national forests, defined as areas that have the potential to expose communities to fire, were estimated at 35 million ha (62% of the total national forest area), and were almost three times larger than the affected community lands. Large contiguous areas of wildfire transmission were evident on a number of national forests. Only 22% of the fireshed area is forested, fire-adapted, and lies within land management designations that allow mechanical fuels management. The methods demonstrate how cross-boundary exposure can be factored into prioritizing federal investments in hazardous fuels reduction on national forests in concert with community protection measures. The results can also help scale wildfire governance systems to match the geography of risk from large wildfire events, which augments existing assessments that do not explicitly identify the source of risk to communities.

Climate change has the potential to influence many aspects of wildfire behavior and risk. During the last decade, Greece has experienced large-scale wildfire phenomena with unprecedented fire behavior and impacts. In this study, thousands of wildfire events were simulated with the Minimum Travel Time (MTT) fire growth algorithm (called Randig) and resulted in spatial data that describe conditional burn probabilities, potential fire spread and intensity in Messinia, Greece. Present (1961–1990) and future (2071–2100) climate projections were derived from simulations of the KNMI regional climate model RACMO2, under the SRES A1B emission scenario. Data regarding fuel moisture content, wind speed and direction were modified for the different projection time periods to be used as inputs in Randig. Results were used to assess the vulnerability changes for certain values-at-risk of the natural and human-made environment. Differences in wildfire risk were calculated and results revealed that larger wildfires that resist initial control are to be expected in the future, with higher conditional burn probabilities and intensities for extensive parts of the study area. The degree of change in the modeled Canadian Forest Fire Weather Index for the two time periods also revealed an increasing trend in frequencies of higher values for the future.