Search Results (259)

The San Juan Islands are one of the few places where native temperate grasslands are found in western Washington State. These ecosystems are important reservoirs of biodiversity and sources of ecosystem services, support many rare and endemic species, and have profound cultural significance to the Coast Salish peoples. These ecologically and culturally valuable ecosystems have become scarce due to the combined pressures of changes in land use, the introduction of non-native invasive species, and the exclusion of fire from the landscape. A lack of historical context and ecological baseline knowledge has made it impossible to fully understand the long-term trends in the extent and distribution of this ecosystem. To address this knowledge gap, we used historical land cover data and multispectral imagery to create a high-resolution, spatially explicit database of grassland extent on the San Juan Islands at multiple time periods since the early years of Euro-American colonization. Our spatial analysis of these data revealed significant decreases in grassland extent between time periods, with an overall 77% net decrease in the extent of non-agricultural grasslands and a loss of 93% of the area of persistent, old-growth grasslands since 1890 across the region. These changes are primarily a result of conversion to agriculture and conifer encroachment or succession to forest. The spatial data and analyses created in this study help to develop the historical baseline of native temperate grasslands on the San Juan Islands, adding to our understanding of the lingering legacy that changes in land use have had on this ecosystem, with the potential to aid in the development of effective conservation and restoration practices. Full article

Post-monsoon open-field stubble burning in northwestern (NW) India—a key agricultural region known as the “breadbasket”—is a longstanding practice used to clear fields. Satellite observations spanning over two decades have revealed significant upward trends in crop production, vegetative greenness, and the frequency of post-harvest fires, with this last contributing to hazardous air quality during the peak burning season (mid-October to mid-November). Since 2022, thermal anomaly data from Aqua-MODIS and SNPP-VIIRS sensors have shown a sharp decline in reported fire events—an observation that contrasts starkly with the concurrent rise in regional aerosol loading detected from space. This apparent discrepancy became particularly pronounced in 2024–2025, prompting a closer examination using high-temporal-resolution imagery from the Advanced Meteorological Imager (AMI) on the geostationary satellite GEO-KOMPSAT-2A. These observations revealed a clear spike in fire-related signals occurring around and after 4:00 p.m. local time, i.e., outside the typical noon to 2:00 p.m. detection window of the MODIS and VIIRS. A fire detection algorithm exploiting the fire-sensitive shortwave-infrared 3.8 μm signal and its contrast to 11.2 μm infrared observations is designed to adopt AMI observations and applied to its multi-year observations (2019–2025). The resulting fire dataset unambiguously shows a gradual shift in stubble burning activity toward the late afternoon hours beginning in 2022 which is underreported by polar-orbiting satellites. The orbital drift of NASA’s MODIS sensor on the Aqua platform allows detection of some of the gradually shifting fires during afternoon hours, but the MODIS still misses a large number of fires occurring around and after 4 p.m. The AMI’s relatively coarse spatial resolution (~4 km), a consequence of its slant viewing geometry over NW India, imposes inherent limitations on quantifying the full extent of fire occurrences. The operational air quality forecasting models currently assimilate satellite fire detections predominantly captured during early afternoon overpasses of the MODIS and VIIRS. The temporal shift in fire activity complicates such forecast, leading to a substantial underestimation of emissions. Intense stubble burning and the resulting air pollution highlight the need for effective crop residue management practices for mitigating the frequency of open biomass burning and thereby reducing episodic degradation of air quality and its associated public health and economic impacts. Full article

Firefighters are potentially exposed to multiple harmful substances, and their activities are classified as carcinogenic to humans. This case study assessed early genotoxic damage (fpg-comet and BMCyt assays) and epigenetic alterations (seven circulating miRNAs) in 35 firefighters compared to 45 non-exposed workers. Occupational exposure to fire smoke was self-reported via questionnaire. Firefighters showed higher median genotoxic DNA damage with respect to the non-exposed group (%DNA tail Buff 19.4 vs. 16.8; %DNA tail Enz 22.2 vs. 19.3; Tail moment 5.5 vs. 4.5; % of apoptotic cells 1.13 vs. 0.97). miRNAs related to air pollution, oxidative stress, tumor suppression, and immune responses, like mir-16, mir-15a, mir-29a, mir-125b, and mir-142, showed significant downregulation (p < 0.001) in the exposed group. Mean percentages of early apoptosis biomarkers and composite DNA damage indices among FF also differed significantly from the other participants (‰Condensed chromatin 0.46 vs. 0.06; ‰Tot anomalies 5.15 vs. 3.82). Multiple correlations emerged, particularly between miRNAs and comet assay parameters, and between comet assay and BMCyt indicators. The implemented integrated approach provides information about the existence of a relationship between genotoxic and epigenetic effects in firefighters, also influenced by time since exposure. Future studies with bigger sample sizes are required. Full article

This study theoretically investigates the role of plant moisture content and its spatial heterogeneity in wildfire dynamics using Cellular Automata models. The model incorporates varying moisture levels and ignition probabilities across different grid configurations, including homogeneous moisture grids and heterogeneous setups with elliptical and segmented high-moisture zones. The relationship between moisture content and ignition probability is modeled using a nonlinear formulation, reflecting threshold-like combustion dynamics observed in real ecosystems. Simulation results show that introducing high-moisture zones significantly reduces the rate of fire spread, with segmented configurations providing the most effective firebreaks. In this context, the ‘suppression effect’ denotes the reductions in forward spread and total burned area attributable to high-moisture regions acting as low-ignitability barriers. The effect is more pronounced when ignition probability depends nonlinearly on moisture, since the nonlinear mapping produces a steeper decline in ignitability above a critical moisture range, which reduces successful transmission across the barrier and increases the likelihood of fire isolation. In particular, the results highlight how modeling can be used as a decision-support tool for the strategic placement of firebreaks. By evaluating alternative spatial configurations of moisture, the approach helps identify barrier designs that maximize containment effectiveness while minimizing ecological and economic costs. This positions the methodology not only as a theoretical contribution but also as a practical framework for guiding firebreak planning and wildfire prevention policies. While the model successfully captures critical fire dynamics, its assumptions of static moisture content and simplified environmental conditions warrant further investigation. Future work will focus on integrating real-time moisture data and refining parameters with observational wildfire data to enhance the model’s predictive capabilities. This study provides valuable insights into the interplay between moisture content and wildfire spread, contributing to the development of decision-support tools for effective wildfire management. Full article

In the framework of plastic circularity, managing end-of-life plastics containing flame-retardant (FR) additives represents a significant challenge. Although FRs are essential for enhancing fire safety in polymeric materials, many FR-containing products are never exposed to fire during their service life. As a result, substantial amounts of still-active FR remain in plastic waste streams. Since mechanical recycling is currently the most widely implemented strategy for plastic waste management, it is crucial to evaluate whether this process affects the flammability and combustion behavior of FR plastics. In this study, polypropylene (PP) containing 21 wt.% intumescent FR (IFR) was reprocessed up to five times to simulate mechanical recycling. After each cycle, the materials were systematically characterized in terms of rheological, morphological, combustion, and mechanical behavior. Although the agglomeration of IFR particles was observed after multiple cycles, the materials maintained stable processability and thermal stability. Importantly, the charring efficiency of the IFR system was preserved, resulting in consistent flammability performance; furthermore, all reprocessed samples achieved UL 94 V-0 classification and exhibited comparable limited oxygen index values. Mechanical properties were likewise largely maintained. Overall, these findings demonstrate that mechanical recycling represents a viable end-of-life strategy for this PP/IFR system, supporting its compatibility with circular material flow. Full article

The background modification of ecosystems affected by fire can cause black or dark colours in animals to become adaptive, providing better protection against visually oriented predators. We surveyed fire-prone Mediterranean woodlands to describe the behaviour, position and background characteristics of the black cicada Tibicina quadrisignata Hagen, 1855 found in recently burnt and unburnt trees. A human detectability test, using cicada pictures in natural backgrounds taken during the fieldwork, was used to assess detection risk. Most cicadas found were solitary males uttering courtship song. Many cicadas flew when approached, with 82% of flight initiation distances being less than 3 m and half of the flights being less than 30 m. Cicadas favoured sunny locations in early morning, and shady sites as the temperature increased. Fire altered fine-scale microhabitat use by cicadas, since cicadas were found in 71% thicker stems and at 14% lower height on the tree, in burnt trees, in relation to unburnt trees. Generalised Linear Mixed Models (GLMMs) revealed a negative fire effect on cicada detection by human test participants. The probability of detection fell from 0.62 in unburnt backgrounds to 0.48 in burnt backgrounds, while the time needed for detection did not change between burnt and unburnt sites. Overall, these results show that T. quadrisignata cicadas adjust their substrate use after fire and are less detectable on burnt backgrounds. Real predation risk, however, also depends on thermoregulation-associated exposure, courtship song activity and predator densities. Full article

Coniferous forests account for 78% of the western US forests and store a substantial amount of carbon. Wildfires significantly alter vegetation structure and associated forest carbon stocks. This study evaluates postfire biomass recovery trajectories (1984–2017) and total biomass accumulation in conifer forests that historically experienced low-severity, high-frequency fire regimes in the western US using recently launched Global Ecosystem Dynamic Investigations (GEDI) mission lidar data. All three ecoregions studied, including the Pacific Northwest (PNW), Southern Rockies (SR), and Northern Rockies (NR), show site-specific biomass recovery trajectories shaped by fire severity. The recovery trajectories were characterized by an initial decline and a variable gain with time since fire across the three ecoregions. Regions with low burn severity recovered to the unburned background state within the first three decades, while regions with higher burn severity only recovered in the Northern Rockies after five decades without fire. Moderate- and high-severity burned areas in both SR and PNW exhibited slow declines or sustained low biomass periods following fires, implying potential ecosystem transformation or an arrested state of lower biomass. Time since fire and fire severity were identified as the most significant drivers of postfire biomass recovery, likely because they reflect both reduced seed availability and the process of seedling establishment and regeneration. In addition, distance to unburned area, drought (measured using the Standardized Precipitation Evapotranspiration Index (SPEI)), elevation, and fire size were important drivers of biomass recovery. Our results demonstrate that all three ecoregions experienced a loss of overall biomass (15–23% (+/−40%)), with the largest losses occurring in the areas with high-severity burns (59% (+/−23%)) in the Southern Rockies compared to unburned forests within the first three decades. This study thus confirms GEDI’s ability to assess disturbance-driven vegetation biomass dynamics and provides an open-science methodology that could be utilized for other regions. In conclusion, our study indicates that an increase in fire severity within low-severity, high-frequency fire regimes, beyond historically observed levels, results in greater carbon losses. It is therefore important to consider the effects of increases in fire severity on vegetation recovery trajectories to infer the future carbon potential in these ecosystems. Full article

Wildfire suppression is often represented in fire spread simulators as static barriers that completely stop fire propagation and are placed at the start of the simulation. Recent works have begun to simulate barriers introduced at different time frames, but these normally act as static barriers. In reality, many water-based suppression tactics (aerial and ground) only slow the fire spread by temporarily increasing fuel moisture and cooling the fuel bed. To address this limitation, we present a new simulation feature: the Dynamic Water Barrier. Unlike static barriers, this representation captures the temporal transient effect of water application, since it is modeled using a simplified water load and evaporation dynamics to estimate changes in live fuel moisture content (LFMC). Implemented using the Fire Area Simulator (FARSITE), the Dynamic Water Barrier reduces the rate of spread and fireline intensity, delaying but not fully preventing fire propagation, providing a transient influence of water-based suppression. The approach was tested on one North American (NA) and one Portuguese fire, where suppression missions were available. The dynamic barriers led to reductions in Relative Area Difference, reaching 0.234 for the Portuguese fire and 0.006 for the NA fire, outperforming the scenario of no combat and having a comparable performance with the full static barrier (RAD 0.108 and 0.024, respectively), while limiting the creation of unburned areas behind the firefront. Although the validation is limited, these findings illustrate the potential to improve tactical decision support and dynamic suppression planning in wildfire management, requiring further studies of other fires and controlled fire suppression missions. Full article

Cultural practices such as Catalonia’s correfocs (fire parades) represent a vibrant expression of intangible heritage. Outdoor activities are conditioned by weather and threatened by climate change. This study analyses the long-term evolution of night-time thermal conditions during correfoc festivals performed in six Catalan towns located on the coast and in the pre-coastal region from 1950 to 2023, using reanalysis-based indicators of air temperature, humidity, and perceived heat as a first exploratory step prior to incorporating in situ meteorological records. Specifically, the Heat Index (HI) and the Universal Thermal Climate Index (UTCI) were computed for the typical event window (21:00–23:00 local time) to assess changes in human thermal comfort. Results reveal a clear and statistically significant warming trend in most pre-coastal locations—particularly Reus, El Vendrell, and Vilafranca—while coastal cities such as Barcelona exhibit weaker or non-significant changes, likely due to maritime moderation. The frequency and intensity of positive temperature anomalies have increased since the 1990s, with a growing proportion of events falling into “caution” or “moderate heat stress” categories under HI and UTCI classifications. These findings demonstrate that correfocs are now celebrated under markedly warmer night-time conditions than in the mid-twentieth century, implying a tangible rise in thermal discomfort and potential safety risks for participants. By integrating climatic and cultural perspectives, this research shows that rising night-time heat can constrain attendance, participation conditions, and event scheduling for correfocs, thereby directly exposing weather-sensitive form of intangible cultural heritage to climate risks. It therefore underscores the need for climate adaptation frameworks and to promote context-specific strategies to sustain these community-based traditions under ongoing Mediterranean warming. Full article

Prescribed fire is a common habitat management tool for white-tailed deer (Odocoileus virginianus Zimm.) that can influence browse quantity and quality. We tested effects of time since burn and number of burns within a decade on browse forage productivity in forested stands in the Pineywoods ecoregion of Texas. We utilized 46 plots on sites managed by the United States Forest Service National Forests and Grasslands in Texas, The Nature Conservancy, and a private landowner. Preferred browse forage species were sampled and analyzed for nutrient content, and years since last prescribed burn and the number of burns within the last 10 years were compared. Deer had strong preferences for plants with greater crude protein, magnesium, and potassium. Crude protein and net energy for maintenance were generally greater with a more frequent burn regime. Different nutrients peaked at different burn intervals. Frequent fires resulted in higher crude protein ($\overline{\mathrm{x}}$ = 14.0%) than infrequently burned sites. At four burns per decade, net maintenance energy was highest ($\overline{\mathrm{x}}$ = 0.6 Mcal Kg⁻¹). Linear regression models only explained between 28% and 41% of utilization, although some preferences for some nutrients, such as crude protein and magnesium, were detected. To improve the nutritional carrying capacity for white-tailed deer, long-term management regimes should incorporate site-specific burn plans that include fire frequency. Timing and burn frequency are critical to achieving optimum results that improve browse forage availability, quality, and utilization. Full article

Reliable geolocation of thermal hotspots, such as smoldering embers that can reignite after vegetation fire suppression, deep-seated peat fires, or underground coal seam fires, is critical to prevent fire resurgence, limit prolonged greenhouse gas emissions, and mitigate environmental and health impacts. This study develops and tests an algorithm to estimate the GPS positions of thermal hotspots detected in infrared images acquired by an unmanned aerial vehicle (UAV), designed to operate over flat and mountainous terrain. Its originality lies in a reformulated Bresenham traversal of the digital elevation model (DEM), combined with a lightweight, ray-tracing-inspired strategy that efficiently detects the intersection of the optical ray with the terrain by approximating the ray altitude at the cell level. UAV flight experiments in complex terrain were conducted, with thermal image acquisitions performed at 60 m and 120 m above ground level and simulated hotspots generated using controlled heat sources. The tests were carried out with two thermal cameras: a Zenmuse H20T mounted on a Matrice 300 UAV flown both with and without Real-Time Kinematic (RTK) positioning, and a Matrice 30T UAV without RTK. The implementation supports both real-time and post-processed operation modes. The results demonstrated robust and reliable geolocation performance, with mean positional errors consistently below 4.2 m for all the terrain configurations tested. A successful real-time operation in the test confirmed the suitability of the algorithm for time-critical intervention scenarios. Since July 2024, the post-processed version of the method has been in operational use by the Corsica fire services. Full article

Wood is a renewable and sustainable environmentally friendly building material. With proper design, it can help buildings achieve lower carbon emissions. However, since wood is a flammable material, its combustion performance in fires has attracted attention. In modern timber structures, glulam is a widely used engineered wood product. Thus, in this paper, glulam specimens made of four kinds of commonly used soft-wood species were used to compare their combustion performance, and the cone calorimeter method was employed. The indicators including time to ignition, heat release rate per unit area, total heat release per unit area, specific extinction area per unit mass, mass of residue, yield of CO and yield of CO₂ were evaluated and compared. The results showed that all the glulam specimens would experience cracking wood and adhesive layer. The time to ignition and peak mass loss rate of the four softwood species in the study was positively correlated with their density. Among these species, Spruce exhibited the highest peak heat release rate and the highest peak CO₂ yield but lowest smoke production, while Douglas fir had a relatively late CO production time and the lowest mass loss percentage, Larch had the lowest heat release rate and total heat release. This study provides fundamental data for the selection of wood structural materials and for future research on wood flame-retardant treatments. Full article

Since March 2021, a series of volcanic eruptions on Iceland’s Reykjanes Peninsula has repeatedly triggered wildfires in moss-dominated heathlands—an unprecedented phenomenon in this environment. These fires have consumed extensive organic material, posing emerging health risks and long-term ecological impacts. Using high-resolution multispectral satellite data from the Copernicus program, we present the first quantitative assessment of the spatial and temporal dynamics of volcanic wildfire activity. Our analysis reveals a cumulative burned area extending 11.4 km² beyond the lava flows, primarily across low-relief terrain. Time series of the Normalized Difference Vegetation Index (NDVI) capture both localized fire scars and diffuse, landscape-scale burn patterns, followed by slow and spatially heterogeneous recovery. Complementary ground surveys conducted in August 2024 document diverse post-fire successional pathways, with vegetation regrowth and species composition strongly governed by microtopography and substrate texture. Together, these results demonstrate that volcanic wildfires represent a novel and consequential secondary disturbance in Icelandic volcanic systems, highlighting the complex and protracted recovery dynamics of moss heath ecosystems following fire-induced perturbation. Full article

The adherents of various religions have during times of prayer and worship oriented themselves toward a fixed, sacred direction or location. Since ancient times, followers of Judaism have turned in prayer to Jerusalem. Traditionally, Zoroastrians have prayed facing a source of light—typically the sun or a fire—representing divine truth and presence. By the second and third centuries of the common era, many Christian communities prayed facing the east when offering the Lord’s prayer and other supplications. Initially, Muḥammad and his followers prayed toward Jerusalem, called the “Qiblih” (a technical word first used in the Qur’án for the direction of ṣalát, the Islamic obligatory prayer), but near the midpoint of Muḥammad’s ministry, the Qiblih was changed to the Kaabah in Mecca. In the mid-nineteenth century, the Báb, founder of the Bábí religion, redefined the Qiblih as “Him Whom God shall make manifest,” a figure whose imminent appearance the Báb anticipated. Years later, Bahá’u’lláh, founder of the Bahá’í Faith, confirmed the Báb’s designation of the Qiblih and claimed to be the figure promised by the Báb—and, thus, the Qiblih. Since Bahá’u’lláh’s passing in 1892, Bahá’ís have regarded the Shrine of Bahá’u’lláh near ‘Akká as their Qiblih. This paper considers three issues related to the concept of the Qiblih. First, it briefly surveys the concept in Judaism, Zoroastrianism, Christianity, Islam, and other traditions. Second, it examines the significance and implications of the Qiblih in Bahá’í texts and their antecedents in Bábí texts. In this regard, it argues that in Bahá’í theology, the Qiblih symbolizes the role, station, and authority of the Manifestation of God, the figure who, in Bahá’í thought, serves as the intermediary between God and humanity from age to age. Moreover, Bahá’u’lláh’s designation of a new Qiblih signaled the independence of the Bahá’í religion. Third, this study explores how from a Bahá’í perspective, Quranic verses concerning the Qiblih may be viewed. These include how Muḥammad’s alteration of the Qiblih to the Kaabah reflected his authority as the Manifestation of God to change a prior law. Further, attention is given to Qur’án 2:143 (“And thus We have made you a middle community…”), which occurs in the midst of the only verses in the Qur’án that decree a change in the Qiblih. Whereas Quranic commentators and scholars of Islam, influenced by the doctrine of Islam’s finality, interpreted the word “middle” (vasaṭ) in this verse as meaning just, moderate, or exemplary, Bahá’u’lláh affirmed the word’s more basic meaning and regarded the Muslim community as a religious community between other communities that preceded it and that will come after it, thus anticipating the emergence of a new religious community, which could potentially have its own Qiblih. Full article

The formation of collective identity and cultural memory is deeply influenced by the historical context and the area in which they develop. Memorial writing entails the reconstruction of the realities of the age under focus, drawing on the author’s objective and especially subjective memories. It is influenced by the one who analyses the events, the language and the underlying values. Thus, the boundary between fiction and reality is often indistinct, as memory gaps are filled with the aid of imagination, without diminishing the documentary value of the text. Since memoirs represent a crossover between history, identity, and literature, an armed conflict can be narrated in many ways. This is also true for Romania’s military campaign in 1913, a moment that is not sufficiently explored by Romanian historiography and literature. Those who serve as chroniclers of the time, enduring endless marches through hostile environments and encountering a largely unfriendly population, contribute to Romanians’ discovery of a reality of the country south of the Danube River that is both similar to and different from theirs. Writers, historians, and publicists fill their pages with memories of a campaign where almost no shots were fired but which resulted in over 5000 victims killed by cholera. Full article