Fire Risk

Fires in urban-forest ecosystems (UFEs) are frequent with complex causes, posing a serious hazard to human lives and infrastructure. Thus, quantifying wildfire risks in UFEs and their spatial pattern is quintessential to develop appropriate fire management strategies. The aim of this study was to explore spatial (geographically weighted logistic regression, GWLR) versus non-spatial (logistic regression, LR) modelling approaches to determine the relationship between forest fire occurrence and driving factors in Yichun, a typical urban-forest ecosystem in China. As drivers of fire, 13 factors related to topographic, vegetation, infrastructure, meteorological and socio-economy were considered and regressed against fire occurrence data from 1980 to 2010. Results demonstrate the superiority of GWLR models over LR in terms of prediction accuracy, goodness of fit and model residuals. The GWLR model further captured the spatial variability of driving factors over a broad study area, and the...

Fires in urban-forest ecosystems (UFEs) are frequent with complex causes, posing a serious hazard to human lives and infrastructure. Thus, quantifying wildfire risks in UFEs and their spatial pattern is quintessential to develop appropriate fire management strategies. The aim of this study was to explore spatial (geographically weighted logistic regression, GWLR) versus non-spatial (logistic regression, LR) modelling approaches to determine the relationship between forest fire occurrence and driving factors in Yichun, a typical urban-forest ecosystem in China. As drivers of fire, 13 factors related to topographic, vegetation, infrastructure, meteorological and socio-economy were considered and regressed against fire occurrence data from 1980 to 2010. Results demonstrate the superiority of GWLR models over LR in terms of prediction accuracy, goodness of fit and model residuals. The GWLR model further captured the spatial variability of driving factors over a broad study area, and the fire likelihood maps identified areas with different zones of fire risk in the study area. In conclusion, the study demonstrates quantitatively and spatially the importance of accounting for local variation in drivers of fires, thereby improving fire management and prevention strategies. The findings also contribute to the emerged field of fire management and fire risk assessment in UFEs.

Converting available biomass from municipal, agricultural and forest wastes to biomethanol can result in significant environmental and economic benefits. Keeping these benefits in mind, one plausible scenario discussed here is the potential to produce energy using bio-methanol in five of the western United States. In this scenario, the biomethanol produced is from different biomass sources and used as a substitute for fossil fuels in energy production. In the U.S. West, forest materials are the dominant biomass waste source in Idaho, Montana, Oregon and Washington, while in California, the greatest amount of available biomass is from municipal wastes. Using a 100% rate of substitution, bio-methanol produced from these sources can replace an amount equivalent to most or all of the gasoline consumed by motor vehicles in each state. In contrast, when bio-methanol powered fuel cells are used to produce electricity, it is possible to generate 12 to 25% of the total electricity consumed annually in these five states. In the State of Washington, thinning "high-fire-risk" small stems, namely 5.1-22.9 cm diameter trees, from wildfire-prone forests and using them to produce methanol for electricity generation with fuel cells would avoid C emissions of 3.7 -7.3 Mg C/ha. Alternatively, when wood-methanol produced from the high fire risk wood is used as a gasoline substitute, 3.3 -6.6 Mg C/ha of carbon emissions are avoided. If these same "high-fire-risk" woody stems were burned during a wildfire 7.9 Mg C/ha would be emitted in the State of Washington alone. Although detailed economic analyses of producing methanol from biomass is in its infancy, we believe that converting biomass into methanol and substituting it for fossil-fuel-based energy production is a viable option in locations that have high biomass availability.

We evaluate whether wildland urban interface households willingness-to-pay for fire prevention is influenced by forest fire risk variables calculated using Geographic Information Systems (GIS). Specifically, we use spatial modeling to calculate estimated fire danger of homes in Colorado and then enter those variables in our logit model of household willingnessto-pay. Including the spatial variables in the models, we found that having a defensible space zone of 10 meters and having a high fire danger in the 100 meter area surrounding their home had a statistically significant influence on willingness-to-pay for fire prevention. For fire suppression, the weighted average fire danger within one mile of their home was the spatial variable that had an influence on willingness-to-pay. The explanatory power of the logit models was noticeably higher with the GIS fire risk variables included.

During the summer of 2001, survey data were collected from Colorado residents living near public lands (i.e., the wildland urban interface). Data were collected by telephone after mailing respondents a survey. These data include detailed information of respondents' views towards wildfire management and willingness-to-pay (WTP) values for prescribed burning. Results indicate that Colorado residents living near public lands are aware that fire is a natural process in their area and are in favor of using prescribed burning for fire risk reduction. They also are willing-to-pay an annual tax for prescribed fire undertaken on the public lands near their homes. Respondents' support for adopting a fire risk mitigation policy based on prescribed fire depended on perceived fire frequency intervals. The substantial WTP values for prescribed burning indicate that the public living in the wildland urban interface could potentially pay an annual tax, so the burden of wildfire management need no longer predominantly lie in the hands of the general taxpayers.

The current paper is aimed at investigating some quantitative and qualitative data, as well as their implications for the space/place/time perspective in terms of fire disaster management in Makana Local Municipality. The working hypothesis of the current article is that fire-fighting under drought conditions will post severe challenges on the disaster risk management system (DRM) in the study area. Methodology of the article includes a combination of document analysis, modelling
using the Google-related tools to track and statistically analyse the public interest in fires, the legislation, and financial/practical implications of the drought on fire disaster management in Makana
Local Municipality. Results of the study indicate that there has been a constant and increasing trend in terms of the South African public’s in fires. That trend is driven by interest in fire-fighting
equipment and possible also by the interest of the South African population in fire-fighting as a career. On causality front, the interest in fires is quantitatively driven by number of fires in South Africa between 2004 and 2017, as well as access to the internet by the South African population.

Leaves and bark are important components of the litter in the Sydney area. This litter is prone to physical degradation, microbial decomposition or can get burnt. Many factors affect the rate, at which the burning or decomposition occurs. Amongst those, the chemical composition of litter and environmental factors play a significant role in regulating litter burning or decomposition. This study aimed to gain insight into the differences in caloric content in leaf and bark for different species. Moreover, the study examined the impact of caloric content on litter decomposition and flammability (time to ignition, flame duration and smouldering duration). Furthermore, the study wanted to understand how different chemicals contribute to interspecific differences in caloric content for both leaves and bark. To explore this, leaves and bark were collected from ten bark-shedding species around the Sydney region. Oxygen bomb calorimetry was performed on leaves and bark to get the caloric contents. The calorimetry results were then combined with already existing datasets on flammability, chemical analysis and decompositions to analyse interactions and responses of flammability and decomposition with changing caloric content. Leaf litter had a higher caloric content, averaging 21.8MJ/Kg whilst bark litter had a lower caloric content, 19.25MJ/Kg. On average, bark had nitrogen concentrations of 0.14%, while leaves had 0.4%. Bark had higher concentrations of lignin (35.6%) than leaves (19.8%). Consequently, more decomposition occurred in leaves than in bark. In addition, fuel with high caloric content ignited more quickly than fuel with less caloric content. Henceforth, this work concluded that higher caloric content results in slower decomposition and higher ignitability of fuel loads. These findings will aid in crafting informed fire predictions and management decisions for forests that deposit considerable fuel and pose higher fire risks.

Measuring success of fuels management is improved by understanding rates of litter accumulation and decay in relation to disturbance events. Despite the broad ecological importance of litter, little is known about the parameters of accumulation and decay rates in Ozark forests. Previously published estimates were used to derive accumulation rates and combined litter measurements, model estimates, and fire scar history data were used to derive a decay constant (k = 0.38). We used accumulation equations to demonstrate temporal changes in litter loading. For example, after a fire event that consumes nearly 100 percent of the litter, about 50 percent of the litter accumulation equilibrium is reached within 2 years, 75 percent within 4 years, and the equilibrium (99 percent accumulation) after approximately 12 years. These results can be used to determine the appropriate prescribed burning intervals for a desired fire severity. For example, fire history data show that the percentage of trees scarred, a surrogate for fire severity, is influenced by the length of historic fire intervals (i.e., amount of litter accumulated). This information will be incorporated into regional fire risk assessments and can be used as a basic knowledge of litter dynamics for both fire management planning and forest ecosystem understanding.

We investigate the effectiveness of a government subsidy and mitigation based insurance contracts at discouraging migration into the wildland interface and at inducing incentives for risk mitigation. We construct a model of the individual migration decision, where the individual maximizes expected utility defined over attributes of locations including cost of insurance and mitigation, wildfire damage, and the availability of a subsidy for reducing wildfire risks through fuel management. Our analysis shows that standard insurance policies provide inefficiently weak incentive for wildfire risk mitigation by offering a low insurance premium to high-risk landowners. We find on the other hand that in the presence of optimal government subsidy, contingent contracts provide an efficient solution where a homeowner chooses a mitigation level that maximizes social benefit and insurers provide actuarially fair contracts such that each individual is offered a premium of the exact value of her wildfire risk.

In biodiversity hotspots like rocky outcrops, species distribution is shaped by environmental factors at multiple scales, with microhabitat characteristics like substrate composition and shelter playing key roles. These fragile ecosystems host a rich diversity of species, including endemic and endangered taxa. However, they remain underexplored in conservation research, despite their crucial role in sustaining xerophilic biodiversity. This study investigates the environmental drivers of xerophilous communities, specifically on land snails and epilithic cryptograms, in a Mediterranean Natural Park. Specifically, we examine how substrate composition influences species assemblages and their biotic relationship. Our field data and statistical models reveal that substrate heterogeneity, comprising conglomerates, pebbles, and sand, creates microclimatic conditions that support diverse communities. Land snails are particularly associated with larger pebbles that provide shelter and moisture retention, while epilithic species thrive on conglomerates and finer materials that stabilize microhabitats. Minimal overlap in habitat preferences between snails and epilithic suggests niche partitioning and complex biotic interactions, highlighting the importance of substrate diversity in sustaining biodiversity. From a conservation perspective, we propose conservation strategies focussed on preserving substrate structural diversity within rocky outcrops to maintain vital habitat features for xerophilous species. Management policies should integrate microhabitat-scale considerations to enhance ecosystem resilience and mitigate disturbances from human and wildlife activities. This research not only advances our understanding of invertebrate ecology in extreme habitats but also offers valuable insights for the conservation of other biodiversity-rich ecosystems facing similar challenges.

Maquis is an important component of Mediterranean vegetation characterized by high specific and structural heterogeneity and complexity. Flammability of vegetation is influenced by several factors (structural and chemical properties, moisture content, etc.) The moisture content of living plants is one of the most critical parameter affecting fire ignition and propagation and represents an important variable in fire behaviour modelling. Plant water content variations depend on both environmental conditions and ecophysiological characteristics of plants. As a consequence, knowledge of seasonal variation of ignitability and vegetation moisture content could contribute to identify critical periods of high ignitability risk in maquis ecosystems. Ignition delay time (ID time) and live fuel moisture content (LFMC) of eight dominant species (Arbutus unedo L. Cistus salvifolius L., Cistus monspeliensis L., Erica scoparia L., Lavandula stoechas L., Phillyrea angustifolia L., Pistacia lentiscus L. and Rosmarinus officinalis L.) of two areas located in North Sardinia, Italy, were measured during two consecutive years. Phenological phases and meteorological variables were also observed. Seasonal patterns of LFMC were compared with two drought meteorological indices. The aims of this work were to evaluate the influence of weather seasonal variations and phenology on LFMC and to analyze the relations between the seasonal patterns of LFMC and the pattern of two drought meteorological indices. Two typical seasonal patterns of ignitability were identified. Cistus salvifolius, Cistus monspeliensis, Lavandula stoechas and Rosmarinus officinalis seemed to be strongly sensitive to seasonal changes. They showed a clear increase of ignitability, during the drought period. For Arbutus unedo, Erica scoparia, Phillyrea angustifolia L. and Pistacia lentiscus the potential ignition risk of the live fine fuel appeared constantly high during the year and not strongly dependent on seasons. These patterns were strictly related to the seasonal variation of LFMC. Significant regression equations were found between plant moisture content and ID time. LFMC seasonal variations of Cistus salvifolius, Cistus monspeliensis, Lavandula stoechas and Rosmarinus officinalis were also well correlated to the drought indices.

The main aim of this work is to identify useful tools to forecast impacts of expected climate change on live fuel moisture content (Live FMC) in Mediterranean shrublands. Moisture content of fine live fuel (diameter < 0.6 cm) was determined periodically during four years on several Mediterranean shrub dominant species of the study area : Cistus monspeliensis L., Pistacia lentiscus L., and Juniperus phoenicaea L. Meteorological variables were also recorded. The potential climate change impact on ignition danger season in Mediterranean Basin shrubland was simulated using the Drought code and future climate scenarios at local scale derived from an advanced high resolution Regional Climate Model realised by CMCC and University of Belgrade (SITRA project).

Land use and nutrient enrichment can substantially affect biodiversity and ecosystem functioning. However, whether and how the responses of community temporal stability to land use and nutrient enrichment change with time remain poorly understood. As part of a 15-year (2005-2019) field experiment, this study was conducted to explore the effects of mowing, nitrogen (N) and phosphorus (P) additions on community temporal stability in a temperate steppe on the Mongolian Plateau. Over the 15 years, N and P additions decreased community temporal stability by reducing the population stability, especially the shrub and semi-shrub stability. However, mowing increased community temporal stability in the early stage (2005-2009) only. Nitrogen addition suppressed community temporal stability in the early and late (2015-2019) stages, whereas enhanced it in the intermediate stage (2010-2014). Phosphorus addition decreased community temporal stability marginally in the early stage and significantly in the late stage. The fluctuations of N-induced changes in community temporal stability are mainly explained by its diverse effects on species asynchrony and population stability over time. Our findings highlight the important role of plant functional groups and species asynchrony in regulating community temporal stability, suggesting that more long-term studies are needed to accurately forecast ecosystem response patterns in the context of global change.

Empirical critical loads for N deposition effects and maps showing areas projected to be in exceedance of the critical load (CL) are given for seven major vegetation types in California. Thirty-five percent of the land area for these vegetation types (99,639 km 2 ) is estimated to be in excess of the N CL. Low CL values (3e8 kg N ha À1 yr À1 ) were determined for mixed conifer forests, chaparral and oak woodlands due to highly N-sensitive biota (lichens) and N-poor or low biomass vegetation in the case of coastal sage scrub (CSS), annual grassland, and desert scrub vegetation. At these N deposition critical loads the latter three ecosystem types are at risk of major vegetation type change because N enrichment favors invasion by exotic annual grasses. Fifty-four and forty-four percent of the area for CSS and grasslands are in exceedance of the CL for invasive grasses, while 53 and 41% of the chaparral and oak woodland areas are in exceedance of the CL for impacts on epiphytic lichen communities. Approximately 30% of the desert (based on invasive grasses and increased fire risk) and mixed conifer forest (based on lichen community changes) areas are in exceedance of the CL. These ecosystems are generally located further from emissions sources than many grasslands or CSS areas. By comparison, only 3e15% of the forested and chaparral land areas are estimated to be in exceedance of the NO 3 À leaching CL. The CL for incipient N saturation in mixed conifer forest catchments was 17 kg N ha À1 yr À1 . In 10% of the CL exceedance areas for all seven vegetation types combined, the CL is exceeded by at least 10 kg N ha À1 yr À1 , and in 27% of the exceedance areas the CL is exceeded by at least 5 kg N ha À1 yr À1 . Management strategies for mitigating the effects of excess N are based on reducing N emissions and reducing site N capital through approaches such as biomass removal and prescribed fire or control of invasive grasses by mowing, selective herbicides, weeding or domestic animal grazing. Ultimately, decreases in N deposition are needed for longterm ecosystem protection and sustainability, and this is the only strategy that will protect epiphytic lichen communities.

The wildland-urban interface (WUI) is the locus of some of the most acute coupled risks between forests and cities, including wildfire losses, biodiversity impacts, and infrastructure vulnerability. Recent global mapping efforts show that the WUI covers only about 4.7% of the land surface but hosts roughly 3.5 billion people-nearly half of the world population-with two thirds of recent wildfireexposed residents living in the WUI.[1, 2] At the same time, algebraic connectivity and Fiedler-vector based edge contributions have become central tools in spectral graph theory and network robustness.[10, 11, 14, 17] This paper introduces the S M Nazmuz Sakib WUI Spectral Coupling Principle, operationalized through three related indices: (1) the S M Nazmuz Sakib WUI Spectral Coupling Number S N , defined as the ratio of the algebraic connectivity of a combined forest-urban graph to the minimum algebraic connectivity of its forest

Large accidents throughout the 20 th century marked the development of safety fields in engineering, devoted to better identify hazards, understand risks and properly manage them. While many such fields evolved rather quickly and moved from a compliance to a risk-based approach, Fire Safety Engineering (FSE) experienced a significant delay in this transition. While the current performance-based approach to FSE provides flexibility and capitalizes on learning from accidental events and other engineering disciplines, FSE is still in many respects decades behind other safety fields and a key issue for the future is how FSE can account for uncertainty in the decision making process. This work provides an overview of the main alternatives to account for uncertainty in safety studies within the context of FSE, including traditional probabilistic analyses and emerging approaches such as strength of knowledge. An example is used to illustrate the impact of the uncertainty analysis on the results of a simplified fire safety assessment. A structured evaluation is performed on each alternative to assess its ease of implementation and communication. The outcome is a compendium of advantages and disadvantages of the alternatives that constitute a toolbox for fire safety engineers to configure and use within their fire risk assessments. Process safety engineers are expected to gain an understanding of the similar and important challenges of FSE, it being directly relevant for process risk management and fire risk management in administrative buildings.