Wildfire risk is increasing in temperate regions like the UK and NW Europe, but we lack operational tools to support wildfire management decision-making needs. We developed FireInSite to address the need for a user-oriented system for predicting fire behaviour. FireInSite is a fire behaviour prediction system in the form of a web-based application that forecasts the probability of ignition, surface fire rate of spread, flame length and fireline intensity for a user selected location for a set of core UK fire prone fuels. By seamlessly integrating geolocated weather forecasts up to 5 days ahead, topographic data, and in-built UK specific fuel models, FireInSite creates an accessible system that removes barriers like the need to gather data from multiple sources and is designed to minimise the number of inputs and decisions users must make before being able to predict fire behaviour. FireInSite can be used to assess the risk of fire in a particular area, plan for fire prevention and suppression, assess the potential effects of fuel load reduction, and educate the public about fire behaviour. We envision FireInSite being useful as a land management planning tool to assess the potential impacts of proposed landscape changes on potential fire behaviour.
FireInSite is built on over four years of intensive data collection of fuel moisture, fuel flammability, and energy contents measured across the UK for key fire prone vegetation types, which have been used to develop fuel models that describe the fire prone fuel types of the UK landscape for the first time. No other fire behaviour prediction system contains fuel models that have been specifically designed and tailored to UK vegetation and are ready inbuilt for use in the system. It also allows the user to select custom developed fuel moisture models, explore past fire behaviour using historical weather records back to 1970, and compare weather and fuel moisture forecasts to conditions in previous years. As FireInSite fuel models capture seasonal variability in fuel flammability and moisture for a range of temperate, humid fuels, we anticipate that FireInSite will also be transferable and of interest for wildfire management in other temperate regions like north western Europe.
How to cite: Clay, G., Little, K., Nikonovas, T., Belcher, C., Vitali, R., Elliott, A., Crawford, A., Kettridge, N., Ivison, K., and Doerr, S.: FireInSite: An accessible, integrated fire behaviour prediction system for wildfire management, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13557, https://doi.org/10.5194/egusphere-egu25-13557, 2025.
In recent years, Italy is facing severe emergency linked to fires. According to the latest reports, over 53,000 hectares of vegetation were lost in 2023, due to arson or negligent fires. Consequences on ecosystem and natural equilibrium are relevant, since the time for the natural restoration process may take several decades. Climate extremes exacerbate Mediterranean area fire risk, due to prolonged drought conditions. On the other hand, hydrogeological risk is also expected to increase over burnt slopes, where surface runoff is incremented due vegetation loss. According to the current legislation, fire risk management is in charge of the Italian Regional Civil Protection (RCP), therefore the development of user-oriented tools, able to prevent the fire hazardous conditions, is key element to ensure the forest-fire risk management. In the proposed model, the atmospheric conditions preceding a forest fire are estimated though the combination of air temperature and relative humidity, as reference of atmospheric parameters. The approach assesses how many times the observed air temperature and RH of the previous 12 days area above the critical conditions (i.e., >25°C and < 50%, respectively). The model calibration and validation are carried out by using a three-years dataset of Abruzzo Region forest fires dataset, that hit the Abruzzo region from 2018 to 2020, combined with meteorological data from civil protection gauges’ network. The developed index identified fire-precursors in the 80% of selected case studies. The missing 20% is mainly related to the meteorological uncertainty in poorly gauged areas. Starting from the index validation, a pre-operational tool forced with European Centre for Medium-Range Weather Forecasts (ECMWF) analyses is also described. The hazard forecasts based on Fire Sentinel Index (FSI), are operational for forest and interface fires forecasting activities on the Abruzzo region, in the framework of a specific agreement signed with the Abruzzo region Civil Protection Agency. The results related to the use of the FSI during the last forest fire prevention campaign that occurred in summer 2024 in the Abruzzo region will be highlighted.
How to cite: Lombardi, A., Pizzi, G., Colaiuda, V., Ferrante, F., Di Antonio, L., Rossi, F. L., Di Fabio, S., Casinghini, M., and Tomassetti, B.: Atmospheric precursors of forest fires: development of the Fire Sentinel Index (FSI) in the Abruzzo Region., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8315, https://doi.org/10.5194/egusphere-egu25-8315, 2025.
Although wildfires bring serious negative environmental and ecological effects, low-intensity fires can promote vegetation recovery to a certain extent, especially in degraded ecosystems. A deeper understanding of the mechanism underlying accelerated vegetation recovery following fire will help provide a reference for the government to formulate ecological restoration strategies and enhance ecological service functions. Low soil nitrogen (N) availability is considered to be a key nutrient factor limiting vegetation recovery. Wildfire may change the coupling relationship between soil N supply and plant N demand to affect vegetation restoration, but little is known about this. We selected the succession sequences of different vegetation recovery stages in low-intensity burned and unburned areas in the karst desertification region of southwest China. We found that low-intensity fire indeed accelerated vegetation recovery, supported by higher plant biomass and diversity in burned than unburned areas. The data of plant leaf N/phosphorus ratio, total N content and δ15N value collectively indicated that plant growth in degraded ecosystems was severely limited by N, while plant N limitation degree decreased significantly following fire. This difference can be explained by the changes in the composition and content of soil N forms and N transformation processes that control their production. Compared to natural vegetation restoration, low-intensity fire significantly increased external N inputs and soil inorganic N supply capacity, primarily by stimulating free-living N2 fixation, organic N mineralization, and autotrophic nitrification rates, more pronounced at the early stage of vegetation restoration. These changes were attributed to improved soil conditions, including increased pH, organic matter content, microbial abundances and macroaggregate following low-intensity fire, all of which facilitated inorganic N production. In addition, plant increased the preferential utilization of nitrate following fire. These results suggest that increased soil inorganic N supply and the adjust in plant N utilization strategy after fire reduce plant N limitation, thereby accelerating plant growth and vegetation recovery in degraded ecological areas.
Keywords: Degraded ecosystem; Low-intensity fire; Plant N limitation; Plant N utilization strategy; Soil inorganic N supply
How to cite: Liu, L. and Zhu, T.: Low-intensity fire stimulates soil inorganic N supply and adjusts plant N utilization strategy to alleviate plant N limitation in rocky desertification area, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4929, https://doi.org/10.5194/egusphere-egu25-4929, 2025.
Wildfires are a global phenomenon that occur across diverse biomes, imposing deep modifications on the quantity and quality (molecular composition) of soil organic matter (SOM). Targeting SOM molecular composition is an ongoing challenge for soil researchers, since SOM is an inherently heterogeneous material with varying functionalities and interactions with the soil mineral phase. The extent and duration of fire-induced SOM alterations are closely tied to fire severity, which is influenced by environmental factors such as climate, topography and type of vegetation. Hence, by addressing SOM molecular complexity in fire-affected soils of diverse ecosystems we aim at (1) identifying factors responsible for drastic SOM transformations, and (2) predicting the occurrence of these changes according to biome of belonging.
In this study, up to 10 topsoils representative of a wide variety of biomes across the globe (from Savannah to Tropical, Mediterranean, Temperate, High-latitude and altitude and Boreal forests) were subjected to a laboratory heating (at 200 and 300 °C) aimed at mimicking the behaviour of fire. Analytical pyrolysis (Py-GC/MS) of bulk soil samples revealed a prevalence of proteins, alkylaromatics and polycyclic aromatic hydrocarbons in burnt soil samples. Conversely, less labile carbohydrate structures along with lignin-derived compounds were observed at higher temperatures. However, some differences were observed across biomes: a relatively greater abundance of compounds that promote soil water repellency (i.e., aromatics) is depicted in Mediterranean ecotone or warmer climates (savannahs), whereas a higher proportion of N-derived compounds is found in cold, wet regions. This work aims at understanding the extent of SOM transformations in fire-affected areas in relation to soil physico-chemical properties such as total nitrogen, organic carbon content and water repellency, and eventually identify the influence of environmental soil forming factors that act a broader scale, such as temperature and precipitation.
Acknowledgments: This work received support from the Spanish Ministry of Science, Innovation and Universities (MICIU) under the research project FIRE2C (ref. CNS2023-143750). N.T. Jiménez-Morillo acknowledges the “Ramón y Cajal” contract (RYC2021-031253-I) funded by MCIN/AEI/10.13039/501100011033 and the European Union “NextGenerationEU”/PRTR.
How to cite: San-Emeterio, L. M., Negri, S., Arcenegui, V., Jiménez-Morillo, N. T., and Mataix-Solera, J.: Decoding molecular changes in soil organic matter in heat-affected soils along latitudinal gradients, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15285, https://doi.org/10.5194/egusphere-egu25-15285, 2025.
In 2020 the Grizzly Creek wildfire burned both sides of the narrow and deep Glenwood Canyon in Colorado, USA. Within the canyon there is a major Interstate Highway (I-70, the only east-west interstate highway across the state of Colorado), a major railroad (the Union Pacific), and a critical waterway (the Colorado River that supplies water to millions of downstream users). Within this canyon, there is a history of life-threatening postfire debris flows from two previous fires (the 1994 South Canyon Fire and the 2002 Coal Seam Fire) that both produced debris flows a few months following the wildfires. Based on this historical knowledge, several government agencies used their combined expertise to coordinate on life-safety decision-making following the Grizzly Creek Fire. After the Grizzly Creek Fire, nine large debris flows were triggered by rainstorms in the summer of 2021, followed by three small debris flows in the summer of 2023. Despite the disruptive postfire debris flow activity, there were no fatalities during these storms, which was largely due to a tiered strategy of hazard assessment/forecasting, monitoring, and adaptation. Many different government agencies worked together to share knowledge and inform decision-making to preserve life safety during these events, including: the U.S. Forest Service, U.S. Geological Survey, Colorado Department of Transportation (CDOT), and the National Weather Service (NWS). Weather forecasts and estimates of debris-flow likelihood, volume, and triggering rainfall thresholds were used to anticipate the location, triggering rainfall, and debris flow volume. These forecasts were compared with rainfall thresholds to determine when to deliver warnings to the public and advise canyon closures. After debris flow triggering rainstorms, the rainfall thresholds were re-evaluated. If a forecast was above the debris-flow rainfall threshold then the NWS would issue a watch or a warning. If the NWS issued a watch, CDOT staff would be positioned at either end of the canyon, and then if the NWS upgraded the watch to a warning CDOT staff would close the highway. This helped to make sure that the public was out of the canyon when there was a potential for debris flows. As the burn area recovered the warnings were adapted based on observations from monitoring. This collaborative model may be helpful in future wildfire situations in areas with critical infrastructure where the mandate for life safety falls across multiple jurisdictions.
How to cite: Rengers, F., Kean, J., Williams, C., Henneberg, M., Banta, J. R., Schroder, E., Sponaugle, C., Callery, D., Walter, E., Blake, T., and Staley, D.: How Government Agency Planning Can Preserve Life Safety from Postfire Debris Flows , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13111, https://doi.org/10.5194/egusphere-egu25-13111, 2025.
Post-fire debris flows (DF) pose a substantial threat to life, property, infrastructure, and water supplies of major cities. For example, post-fire DF resulted in 23 deaths in Montecito, California following the 2018 Thomas fires (Kean et al., 2019). Major fires this year at the wildland-urban interface in Los Angeles have again primed the region for major potential post-fire hydro-geomorphic risks. In Australia, post-fire DF in 2003 resulted in the closure of the capital city’s major water supply for several months (White et al., 2006), and modelling shows that Melbourne’s water supply is at high risk of contamination for up to a year if (or when) its forested water supply catchments are burned by wildfire (Nyman et al., 2020). One of the few feasible mitigation strategies to protect communities, infrastructure and high-value catchments from these devastating impacts is the broadscale application of surface mulches to burned hillslopes. However, while multiple studies have investigated the effectiveness of these treatments in reducing post-fire erosion and runoff, very few have evaluated its effectiveness specifically in the context of DF risk mitigation, and none (to the authors knowledge) have empirically (i.e., using field experiments) linked the effectiveness of these treatments to DF initiation likelihood and risk to assets. As a result, any meaningful cost-benefit analysis (CBA) of hillslope treatments is currently not possible. This knowledge gap is particularly important because, while the post-fire risks to life and property are substantial, the costs of broadscale hillslope treatments in difficult terrain are also substantial (~$5,000USD hectare-1 (Robichaud et al, 2013)). The aim of this research was to quantify the effectiveness of surface mulch (wood shred) treatments in reducing the likelihood of DF initiation in recently burnt landscapes, and to integrate these observations within a purpose-built modelling framework that can be used for rapid CBA of DF risk mitigation.
We combine experimental field data from 12-months of monitoring (natural and simulated rainfall events) at twelve 30m2 runoff plots, treated at varying wood shred application rates, with a DF initiation model to estimate the reduction in DF risk using a novel approach. The protection of water reservoirs is used as a case-study to illustrate how altering DF risk through surface mulch application has direct and substantial impacts on critical infrastructure, using a hydrodynamics model to quantify reductions in water contamination risk. Risk reductions are presented in applied terms (dollars per headwater treated vs. number of debris flows prevented in the landscape) to enable rapid CBA for land managers. Initial results indicate wood shred treatment increases soil infiltration capacity by 50% in high-intensity rainfall events which translates to substantial reductions in DF and water contamination risk. While we use water contamination as a case study to illustrate the impact to assets, this approach can be used to enable CBA for the protection of other critical infrastructure. With huge costs associated with both debris flow damage and with mitigation techniques, the need to undertake empirically based CBA is paramount to both management agencies and communities.
How to cite: Harrison, M., Smalley, F., Barton, H., Noske, P., Lane, P., Lyell, C., Keeble, T., and Sheridan, G.: A field-parameterised model for quantifying the reduced probability of post fire debris flows in response to hillslope surface wood shred treatments, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14425, https://doi.org/10.5194/egusphere-egu25-14425, 2025.
Wildfire disturbance propagation along fluvial networks remains poorly understood. We use incident, atmospheric, and water-quality data from the largest wildfire in New Mexico’s history to quantify how this gigafire affected surface runoff processes and mobilized wildfire disturbances into fluvial networks after burning 1382 km2. Surface runoff post-fire increased compared to pre-fire conditions, and precipitation events that are frequently observed in the affected watershed (<2-year recurrence) and fell during the post-fire first rainy season resulted in uncorrelated, less frequently observed runoff events (10-year recurrence). Besides these shifts in runoff generation, the magnitude and fluctuation of daily water quality parameters and relevant ecosystem processes also shifted over multiple months, even at sites located >160 km downstream of the burn perimeter. Our findings emphasize the need to incorporate spatially resolved longitudinal sampling designs into wildfire water quality research and highlight the spatiotemporal co-dependency among atmospheric, terrestrial, and aquatic processes in defining the net outcome of wildfire disturbance propagation along impacted fluvial networks.
How to cite: González-Pinzón, R., Nichols, J., Joseph, E., Kaphle, A., Tunby, P., Rodriguez, L., Khandelwal, A., Reale, J., Regier, P., and Van Horn, D.: Longitudinal propagation of aquatic disturbances following the largest wildfire recorded in New Mexico, USA, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7045, https://doi.org/10.5194/egusphere-egu25-7045, 2025.
Wildfires are a known treat causing relevant impact on the ecosystem, population and economic infrastructures. They are becoming more and more frequent and severe due to climate changes, and future scenarios are now considering their occurrence into currently fire-resistant areas at higher latitudes. Because of this, the assessment of hazard associated to wildfires require considering also medium to long term effects on the environment. Wildfires induce physical and chemical changes on soil with consequent soil structure losses and formation of water repellent layers. These changes, coupled with canopy cover removal increases runoff and postfire erosion. Enhanced sediment transport is associated with vegetation removal and increased runoff and can remobilize previously deposited material stored in slopes and channels. Moreover, thermal spalling of rocks exposed to wildfire can produce new debris.
Wildfire dramatically changes the degree of Sediment Connectivity: the degree of connection peaks during and just after the wildfire, due to canopy cover removal. Vegetation recovery intermittently changes the degree of sediment connection, affecting the susceptibility to erosion and debris flow likelihood.
As a type case study, we choose the 2021 Montiferru-Planargia (Sardinia) wildfire. We conducted a three-year monitoring of the burnt scar. Immediately after the fire slopes and channels were covered by sparse debris produced by rockfall before the fire and by thermal spalling during the wildfire. Those debris were removed by postfire runoff and involved in postfire debris flows over 33 catchments. Postfire sediment connection changed as vegetation recovered: some catchments were stabilized after one year whereas others experienced debris flow even in the second year. We calculated NDVI over three years at one-month interval and successfully found a NDVI threshold which efficiently represents sediment disconnection induced by vegetation recovery. Our findings are expected to improve erosion susceptibility assessment after wildfire.
How to cite: Pala, C., Melis, M. T., Brunetti, M. T., Pioli, L., Sarro, R., Miranda Garcia, P. V., Galve Arnedo, J. P., and Millares Valenzuela, A.: Vegetation Recovery and Sediment Connectivity in burnt catchments: A case study of the 2021 Montiferru Wildfire Study Case using remote sensing data, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20219, https://doi.org/10.5194/egusphere-egu25-20219, 2025.
Wildfires remain a significant challenge in fire-prone regions like Southern California, as evidenced by the ongoing 2024/25 wildfire disaster. This study introduces an innovative methodology for assessing wildfire risk by combining Fire Weather Index (FWI) components, historical burn probabilities, and multi-source meteorological and satellite data, including ERA5 reanalysis, MODIS and Sentinel-2 data.
The methodology includes a decomposition of FWI components — including temperature, wind, humidity, and fuel moisture—and their derived indices: Fine Fuel Moisture Code (FFMC), Duff Moisture Code (DMC), Drought Code (DC), Initial Spread Index (ISI), Build-Up Index (BUI), and the final Fire Weather Index (FWI). The Fire Weather Index (FWI) meteorological data will be sourced from the Copernicus ERA5 dataset because the ERA5 data provides essential weather information, including wind speed, surface temperature, and relative humidity. These parameters are cross-referenced with MODIS-derived Land Surface Temperature (LST) to validate spatial temperature trends, statistically downscale the derived data, and identify discrepancies that could signal pre-fire anomalies. Additionally, satellite-derived vegetation indices from Sentinel-2 (e.g., NDVI, NDWI, and MSAVI2) are incorporated to evaluate vegetation health and moisture stress. Before the fire, the vegetation states are compared with historical burn probability mapping, constructed using past wildfire records and environmental datasets, to create a comparative framework to assess predicted versus actual fire spread patterns.
The working hypothesis suggests that combining ERA5 meteorological data with satellite-derived indices can provide a deeper understanding of pre-fire conditions, thereby improving early warning capabilities. Preliminary findings suggest that anomalies such as elevated temperatures (from MODIS and ERA5) and vegetation stress (from Sentinel-2) are strong indicators of impending wildfire risks. These patterns highlight the importance of combining meteorological, historical, and satellite-based insights to inform wildfire risk management.
We propose developing an interactive early warning system using Google Earth Engine to operationalise these insights. This system integrates FWI components, ERA5-derived meteorological data, historical burn probabilities, and satellite-based indices into a dashboard for real-time monitoring. The dashboard will be designed to visualise critical thresholds, assess vegetation stress, and analyse fire risk trends. This comprehensive approach empowers proactive decision-making to mitigate the impacts of wildfires and improve overall disaster preparedness.
This study demonstrates the potential of leveraging cross-referenced ERA5, MODIS and Sentinel-2 data, FWI components, and historical probabilities to build a scalable, data-driven framework for wildfire risk assessment in vulnerable regions.
How to cite: Van den Dool, H. G. and Bidwai, D.: Improving Wildfire Prevention: Combining FWI Components, Historical Burn Probabilities, and Multi-Sensor Satellite Data for Better Early Warning Systems in Los Angeles, CA, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12639, https://doi.org/10.5194/egusphere-egu25-12639, 2025.
Wildfires present a significant threat to heather-dominated moorlands and heathlands, especially as climate change exacerbates fire risks, underscoring the need for effective management strategies to mitigate fire spread. This research investigates the effects of different management approaches, burning, cutting, and leaving areas unmanaged, on fire spread rates in the Scottish region. The study focuses on patches with varying years of intervention, 2019, 2015, and 2007, alongside patches that were left unmanaged. Fieldwork was conducted to gather data on vegetation height, while dead fuel moisture was calculated using the Nelson Fire Model, which derives estimates from weather parameters collected at a local weather station. Fire behaviour, particularly surface fire spread rates, was simulated using BehavePlus software, with specific fuel models assigned based on vegetation height.
Preliminary analyses indicate that different management practices result in varying fire spread rates, highlighting the importance of vegetation height and the timing of interventions. Vegetation height emerged as a critical factor, and the study highlights the importance of implementing management interventions within optimal time intervals to maintain their effectiveness. These findings suggest that management strategies could play a critical role in mitigating wildfire risks and provide a foundation for further research into optimising practices for enhancing wildfire resilience in the UK’s moorlands and heathlands.
How to cite: Mousavi, Z., Belcher, C., Baker, S., and Kettridge, N.: Evaluating the Impact of Management Strategies on Fire Spread in Heather-Dominated Moorlands, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5961, https://doi.org/10.5194/egusphere-egu25-5961, 2025.
The practise of using fire as a tool to manage the landscape has been around for thousands of years. Today, a range of different land management practises exist including ‘modern’ techniques such as mechanical cutting/mowing of vegetation, scraping as well as the ancient use of controlled burns. Each of these land management practises act to reduce fuel loads and can provide fire breaks, and therefore present as useful tools that can be used to mitigate against the effects of wildfires.
Each of these land management tools are commonly practised across the UK. Here in the UK, there is an increasing threat from wildfires, that have the ability to result in the severe degradation of habitats. However, how well each of these management practises limit the impact of wildfire on UK fire prone habitats and the resulting ability of those habitats to recover following wildfire, is currently unknown. The IDEAL UK Fire - seeks to generate data to make Informed Decisions on Ecological Adaptive Land Management for mitigating UK Fire, by assessing how human-fire use compares with different landscape management practises regarding its impact on vegetation diversity and habitats across the UK, as well as comparing these with areas that have had little/no human management interaction and have experienced wildfires. We present details on the IDEAL UK Fire project and our findings to-date, emphasizing the varying degrees of habitat resilience in fire-prone landscapes across the UK, using both ancient and modern land management tools.
How to cite: Baker, S., Belcher, C., Kettridge, N., Doerr, S., Gr, L., Wayman, J., Heinemeyer, A., and Gaston, K.: IDEAL UK Fire Project: Assessing the relationships between management tools of the UK landscape and their impacts for habitat resilience and wildfire mitigation , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15333, https://doi.org/10.5194/egusphere-egu25-15333, 2025.
The reed belt of Lake Neusiedl, with an area of 181 km², covers more than half of the total lake area (ca. 320 km²) and is part of the Natura 2000 and Ramsar Conservation site of lake Neusiedl. It is the second biggest contiguous reed ecosystem in Europe after the Danube delta. The ageing of the reed belt and subsequently growth of the reed mats represents an obstacle for numerous bird species worth protecting such as the Great Reed Warbler and Reed Buntings in the National Park Lake Neusiedl because many are specialized and dependent on the presence of younger reed plants (Phragmites australis). Traditional regeneration measures, most notably mowing, are becoming decreasingly suitable as a management tool due to warmer temperatures and subsequently insufficient freezing in winter. Therefore, prescribed burning of old reed stands, which is currently prohibited by Austrian law, is being considered as a regeneration measure as a way to maintain invaluable habitats for bird species. For this reason, a pilot study was carried out in January 2024 in the reed belt of Lake Neusiedl near Jois (province of Burgenland, Austria) in order to gain insights on consequences of controlled burning of old reed mats. The burning was conducted in winter to minimize harm of wildlife. Our research includes pre- and post-fire laboratory analyses of biomass and carbon content from standing vegetation, litter (matted reed), and the underlying partially decomposed organic soil layer. Furthermore, the fire behavior and intensity, as well as moisture contents during and after the fire were monitored. To support the area-wide mapping UAV-LiDAR and RGB flights were undertaken. The results can provide valuable insights into the closely linked balances between nature conservation and carbon stocks that arise in the management of reed-dominated ecosystems through burning. The mean fire temperature was slightly above 700°C and peaked at 1034°C. A total area of 15.6 ha was affected, on which the standing dead reed was lost completely, and the reed mats were reduced by 31.2% on average. A total of 54.5 tC were released from the study area. The layer of matted reed, which is to be affected by the fire, should have a maximum moisture content of 30% to ensure biomass removal. A significant reduction of the matted reed horizon thickness was achieved, which will help Phragmites australis regrowth and young-stock-specialized bird repopulation. The fire also left unburned patches of intact old stock behind, which could provide habitats for bird species specialized in old reed stock. Our results indicate that prescribed fire can be a suitable management tool at the reed belt of lake Neusiedl for the purpose of reed regeneration and habitat restoration.
How to cite: Berner, R., Neumann, M., Müller, M. M., Hollaus, M., and Glatzel, S.: Prescribed burning as potential regeneration technique in temperate reed ecosystems - a pilot study at Lake Neusiedl, Austria, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4418, https://doi.org/10.5194/egusphere-egu25-4418, 2025.
Parametric insurance offers a novel approach to financial risk management for wildfires, with payouts triggered by objective measurements, or model outputs, rather than traditional loss assessments. WTW has pioneered the adoption of parametric forest fire insurance, leveraging satellite measurements of changes in reflectivity over vegetation, thermal anomaly detection, and fire perimeter determinations from independent fire agencies.
We present mock examples of how extreme wildfires may trigger parametric insurance payouts, specifically applied to forested areas in the 2025 Los Angeles fires. This is in the context of how the insurance industry has adapted to extreme wildfires over the past decade. We also demonstrate how fuel reduction can significantly mitigate wildfire risk, offering critical insights into the interplay between risk reduction strategies and insurance.
How to cite: Williams, D.: Parametric insurance for forest fires: the ART of the possible, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17042, https://doi.org/10.5194/egusphere-egu25-17042, 2025.
Understorey forest fires in tropical dry deciduous forests are an ecologically significant yet understudied phenomena, particularly in India, where such fires occur frequently but have been largely overlooked for decades. This study examines the effects of understorey fires on the physicochemical properties of in-situ lateritic soils (Haplustalfs, Paleustalfs, and Ustifluvents, as per USDA Soil Taxonomy) in the eastern Indian state of West Bengal. During the 2024 fire season (February–May), soil samples were collected from 12 sites, comparing burnt and unburnt patches at depths of 0–5 cm, 5–10 cm, and 10–20 cm. Fire temperatures recorded at three sites using infrared pyrometers ranged from approximately 500°C to 1100°C, with a fire spread rate of about 8 m/hr. The predominant soil textures in the study area are sandy clay loam and sandy loam. The results reveal that understorey fires significantly (p < 0.05) altered the topsoil (0–5 cm), increasing pH, electrical conductivity (EC), organic carbon (OC), nitrogen (N), potassium oxide (K₂O), and organic matter (OM), likely due to ash deposition and the partial combustion of organic material. We also observed a significant reduction of bulk density (BD) at the 0–5 cm depth in burnt areas, likely due to the loss of fine roots and soil moisture during the fire, which would cause loosening of the soil structure. However, no significant differences were observed in aggregate stability, Visual Evaluation of Soil Structure (VESS) scores, base cation concentrations (Ca, Mg, Na), phosphorus (P₂O₅) or cation exchange capacity (CEC) between burnt and unburnt sites. Minimal changes were recorded at depths beyond 5 cm, attributed to limited heat penetration and the absence of pyrogenic residues. These results diverge from the general understanding of fire effects on soil properties. In ecoregions dominated by highly flammable vegetation, such as coniferous forests and grasslands (e.g. in US, Canada or Australia), large-scale crown fires disrupt entire forest ecosystems and effectuate heat-induced alterations and nutrient volatilisation, which profoundly affect soil properties. On the contrary, understorey fires in deciduous forests primarily influence the forest floor, predominantly consuming low-lying vegetation, leaf litter, and organic matter, resulting in turn in immediate nutrient enrichment in the topsoil (0–5 cm), which may facilitate post-fire vegetation recovery. The observed soil changes are driven more by ash deposition and incomplete combustion of organic matter than by nutrient volatilisation, distinguishing them from the more intense fire behaviours elsewhere. These variations in fire intensity and behaviour likely explain the differences in soil responses. However, the long-term risks of ash depletion and nutrient loss through water-driven erosion pose significant concerns for post-fire forest landscapes, potentially degrading soil productivity, disrupting forest regeneration, and threatening overall ecosystem resilience. These findings emphasize the need for comprehensive research to fully comprehend the long-term implications of understorey fires in tropical dry deciduous forests.
How to cite: Mallick, K., Majhi, A., and Patel, P. P.: How do understorey fires in deciduous forests affect soil properties? Insights from Eastern India, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-604, https://doi.org/10.5194/egusphere-egu25-604, 2025.
Soil is exposed to increasing threats from human activities, including land use change and abandonment, as well as climate change-induced events such as droughts, floods and wildfires. Although the Mediterranean environment has a coevolutionary history with fire, it is not exempt from the threat posed by the recent increase in the frequency and severity of this disturbance. In Italy, for instance, the total burned area in 2021 exceeded that of 2017, a year remembered as particularly critical from this point of view.
In this context, the research project FLER_MeCoFor aims to study the conservation status, sensu Habitats Directive, of the Habitat of priority interest 2270* - Wooded dunes with Pinus pinea and/or Pinus pinaster, of the Special Areas of Conservation (SAC) IT9130006 (Apulia, Southern Italy). In particular, several wildfires from 1981 to 2020 affected different pinewoods within the SAC.
Here, this study presents preliminary results of the medium-term impacts of fire severity on soil properties following the most recent wildfire that occurred in 2020 within the Patemisco pinewood. Four years after the fire and prior to the fieldwork (April 2024), areas of different levels of fire severity (Low, Medium and High) were identified through differenced Normalized Burn Ratio (dNBR) index analysis by remote sensing. At sites representing the three different fire severity levels and at a nearby unburned (control) site, litter and mineral soil samples (depth 0-5 cm, 5 replicates per site) were collected to determine the physical, chemical and biological properties of the soil.
Spectral variations between pre- and post-fire images assessed by dNBR index, in addition to guiding the field sampling, suggested potential alteration in soil characteristics in the most severely affected areas. The effect of the fire was still evident within the litter layer four years after the fire. Although this layer was observed in the low and medium severity burnt sites, it was significantly lower (in terms of weight) than the control. Furthermore, no litter was found in the high severity burnt site. Preliminary results on the mineral soil analysis showed that the burnt sites had no significant changes in the physical properties compared to the control. On the contrary, an increase in pH and a decrease in organic carbon content were still detected at all burnt sites, as a function of fire severity.
These changes suggest a potential alteration in the soil microbial community. For this purpose, further investigations, aiming to reveal the effect on the soil microbial activity and biomass, are fundamental for a comprehensive understanding of the fire recovery status of this woodland. Considering the significance of the Habitats of priority interest conservation for overall ecosystem functioning, this research is essential for developing post-fire land management measures to mitigate the impacts of forest fires.
How to cite: Marfella, L., Rossana, M., Spatola, M. F., Pazienza, G., Mairota, P., Strumia, S., Padoa-Schioppa, E., and Rutigliano, F. A.: Wildfire early effects on soil properties in Mediterranean pinewoods: Insight from the 2020 Wildfire in Patemisco, Italy, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13423, https://doi.org/10.5194/egusphere-egu25-13423, 2025.
Covering approximately one third of the United States of America, sagebrush-dominated ecosystems are an important part of the continental USA’s landscape. The effects of wildfires on the hydrology of semi-arid sagebrush ecosystems are poorly understood and, as these areas experience more frequent wildfires, are becoming more relevant. As part of a multi-disciplinary project studying wildfire in sagebrush ecosystems – “Harnessing the Data Revolution for Fire Science” – a field experiment near Reno, Nevada, was set up to better understand the effects of fire on the hydrology of sagebrush ecosystems by measuring the hydraulic properties of the soil before and after prescribed burning. In the spring of 2024, twenty 3x4 meter experimental plots were outfitted with instruments for soil moisture and temperature monitoring; at least 2 TOMST TMS4 probes were placed in each plot in areas with different post-fire vegetation, recording measurements at 15-minute intervals. These data are supplemented with intermittent measurements of shallow soil moisture using a Campbell Hydrosense II Probe to measure a greater number of points within each plot. The two instruments were calibrated in the lab with soil from the experimental plots to ensure accurate and comparable volumetric water content values. Infiltration and water repellency measurements under different vegetation covers within each plot provide context for interpreting variations in the soil moisture data. In fall 2025, 10 of the 20 experimental plots will be burned, which will allow us to compare the hydraulic properties of the same soil before and after the fire, therefore directly assessing fire impact on soil hydrologic properties. Here we introduce the field experiment and address the calibration of the Campbell HydroSense II and TOMST TMS4 soil moisture probes, while also providing a site characterization with the first year of pre-fire soil moisture, temperature, infiltration, and water repellency data.
How to cite: Croskery, C., Okyere, J., Boisramé, G., Kozloski, R., and Berli, M.: Fire Impacts on Soil Hydraulic Properties in a Sagebrush Ecosystem in Nevada, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13906, https://doi.org/10.5194/egusphere-egu25-13906, 2025.
Wildfires have a significant impact on soil erosion. Most studies emphasize on the "disturbance window", which typically ranges from 3 to 10 years. Studies on the long-term effects of fire on soil erosion are relatively few, especially when it comes to studies that go beyond 20 to 30 years after the fire.
This study carried out at Seich Sou, a suburban forest in Thessaloniki city, North Greece. A wildfire in 1997 destroyed half of the forest, and another one occurred in 2021. This study focuses on investigating the long-term (1997 wildfire) and short-term (2021 wildfire) post-fire impacts on erosion in relation to rainfall intensity and rainfall erosivity (R factor). Field plots using silt fences were installed, to quantify soil erosion in both burned and unburned regions.
Regarding the short-term effects of the wildfire in 2021 on soil erosion, the findings indicated that vegetation is the primary factor influencing annual erosion rates. Soil erosion in burned plots is significantly influenced by rainfall intensity, particularly when it surpasses 6–7 mm/30 min. However, in burned plots it was revealed that soil erosion did not significantly increase when the rainfall intensity increased beyond 10 mm/30min. On the other hand, in the unburned plots, soil erosion was considerably increased beyond a certain threshold of rainfall intensity (>10 mm/30 min).
For the first time in literature, it was revealed that when two consecutive and very intense storms occurred, the second, more intense rainfall generated noticeably less erosion rates than the first. An average 20% reduction in soil erosion (both in burned and unburned plots) was observed after the second storm, when the R factor increased by 690%. The main reason for this behavior is the quick depletion of the available sediments caused by the high-intensity consecutive rainfalls, which decreased the erosive effect of the second consecutive storm.
We also found that since both major erosive episodes were so close to one each other in time, the considerable rise in R factor in the second post-fire year did not significantly increase soil erosion. These results demonstrate that the R factor in RUSLE, which is used to determine the annual erosion rate in burned and unburned regions, without the appropriate reference to the corresponding field data, which used to validate the model, has potential significant errors that may lead to inaccurate erosion rate estimations. Before implementing the erosion model into practice, researchers and stakeholders that utilize the R factor in erosion modeling should thoroughly investigate the precise dates of the significant erosive events.
Concerning the long-term effects of the 1997 wildfire, the findings from the "natural reforestation" plots showed that, 25 years after the wildfire, erosion rates are three times higher (0.062 t/ha/year) than those of the "control" plots (0.023 t/ha/year). The forest ecosystem has not significantly recovered, and it seems that the "window of disturbance" in the reforested area has not been closed. Depending on site quality, geomorphology, and meteorological conditions, it may take more than 20 years to return soil erosion rates to normal levels in Mediterranean environments, where soils are typically thin and rocky.
How to cite: Kastridis, A., Margiorou, S., and Sapountzis, M.: Post-fire short- and long-term soil erosion monitoring – The impact of consecutive storm events on R factor and erosion rates , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-556, https://doi.org/10.5194/egusphere-egu25-556, 2025.
Firebreaks are now perceived as crucial for managing wildfire propagation in fire-prone regions. In present-day Portugal, one of the countries most affected by wildfires worldwide, bulldozers are deployed during fire events to rapidly construct emergency firebreaks, locally enhancing firefighters' response capabilities. Often driven by emergency needs, these firebreaks are created on steep forested terrain without any prior planning and are typically abandoned after the wildfire has been extinguished, i.e., without any efforts to control soil erosion.
The impacts of these firebreaks on hillslope hydrology and associated soil erosion are poorly understood, and to the best of our knowledge, no studies have specifically addressed this issue. The present research aimed to fill this gap by investigating the impact of one such emergency firebreak on soil erosion during the immediate post-fire period and assessing the effectiveness of pine needle mulch application as a potential mitigation technique. The studied firebreak was created in a terraced Maritime Pine plantation, involved the scraping-off of the topsoil layer and compacting it with the bulldozer tracks and was very steep, with an overall slope angle of 37%.
At the study site, three pairs of geo-textile bounded plots, each 8 meters long and 2 meters wide (16 m²), were installed immediately following a wildfire that occurred at the end of September 2024 in the Caramulo Mountains, north-central Portugal. At the bottom of each plot, sediment fences were used to collect sediments at rough monthly intervals. Rainfall was measured using automatic and totaliser rain gauges, while ground cover evolution over time was tracked using near-vertical photographs taken manually during each field visit.
Preliminary results revealed substantial soil erosion from the firebreak, with median sediment losses of 31 Mg·ha⁻¹ during the first four post-fire months. The occurrence of rills was observed within the first month, highlighting the high erodibility of these firebreaks, and are now being monitored by terrestrial laser scanning. These preliminary findings point to an urgent need for monitoring soil erosion of firebreaks on steep terrain and starting to apply and evaluate erosion mitigation measures.
How to cite: Martins, M., Caetano, A., Gruntova, A., Fantini, C., Lange, R., Pereira, L., Nunes, J., and Keizer, J.: Emergency firebreaks: the post-fire erosion impact in mountainous areas of North-Central Portugal, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20411, https://doi.org/10.5194/egusphere-egu25-20411, 2025.
