This growing threat calls for urgent scientific attention to better understand the effects of wildfires on ecosystems and to develop integrated tools for land management before and after fires. Such efforts are essential for reducing vulnerability to wildfires and mitigating their impacts. However, this challenge extends beyond the scientific community, requiring the active involvement of stakeholders and policy-makers worldwide, as fundamental resources, such as water, soil, raw materials, and habitats, are at risk.
This session invites contributions from researchers studying the effects of wildfires on ecosystems, covering the full spectrum from prevention to post-fire recovery. We welcome laboratory, field, and modelling studies on the following topics:
i. Prescribed and/or experimental fires
ii. Fire severity and burn severity
iii. Fire effects on vegetation, soil, and water
iv. Post-fire hydrological and erosive responses
v. Post-fire management and mitigation
vi. Socio-economic aspects of pre- and post-fire land management
vii. Fire risk assessment and modelling
Increasing wildfire impacts highlight the importance of studying wildfire behaviour and effects to develop effective management and mitigation strategies. Prescribed fire has demonstrated to be a powerful tool for land and fire risk management. However, optimizing its use requires detailed knowledge of the complex relationships between fire, vegetation, and atmospheric dynamics. In this work, we demonstrate how airborne remote sensing facilitates the analysis of fire behaviour and its effects on vegetation. We will present airborne long-wave and mid-wave infrared imagery collected over a prescribed fire during the Fort Stewart Integrated Research Campaign in 2024.
The data consists of seven video sequences with a total duration of one hour and fifty-four minutes. The collected imagery was pre-processed and georeferenced by integrating inertial measurement unit data, then further stabilized using feature matching techniques to mitigate helicopter-induced jitter. This dataset will be utilized to investigate the relationship between essential fire behaviour metrics, such as fire rate of spread and fire radiative power, and vegetative conditions before, during, and after combustion, thereby providing insight into fuel consumption and fire impacts. This analysis will be useful to validate fire behaviour models and improve the capacity to forecast fire behaviour during prescribed fires, which is bound to have a significant impact on wildfire management in the future.
Acknowledgements: This work was supported by the U.S. National Science Foundation under award number 2053619, the USDA Forest Service Fire and Smoke Model Evaluation Experiment (FASMEE), the US Strategic Environmental Research and Development Program (SERDP) under project RC20-1364, and the EU COST Action NERO (CA22164).
How to cite: Manoj Santhi, S., Stockmans, T., Olivera Prieto, P., Giesige, C. C., Goldbeck Dimon, E., Klofas, A., Clements, C. B., and Valero, M. M.: Airborne Infrared Remote Sensing for Characterizing Wildfire Behaviour in Prescribed Fire, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6737, https://doi.org/10.5194/egusphere-egu26-6737, 2026.
In March 2023, a record area of 418 hectares was burnt in forest fires across the Goan region of the Central Western Ghats(CWG). We investigated the causes of this sudden forest fire using live meteorological and phenological datasets collected before, during, and after the incident from our PhenoMet tower located in the Netravali Wildlife Sanctuary (WLS) in the CWG. The farmers of forest fringes used conduct controlled burning on their farm, which sometimes results in minor forest fires. In 2023, this activity gone out of control and led to unprecedented forest fires. The State forest department reports that the fire occurred between 4th to 15thMarch 2023. A review of literature suggests that the fire weather conditions are generally associated with prevalence of > 280c mean daily temperatures, <40% daily mean humidity, and, > 380c maximum daily temperature, and > 250c daily minimum temperature. We found that the onset of the forest fire on March 4 marked with a maximum temperature exceeding 37°C, a mean daily temperature above 28 °C, and a daily average humidity of 27%, with a minimum of 13%. The fire weather conditions initiated on February 22 and persisted until March 15, lasting for 22 days. While the onset of the forest fire was associated with low humidity values along with other weather parameters, the dousing of fires was associated with a notable increase in humidity values. We noted a perceptible change in the weather parameters close to March 15 with the Daily Average Humidity values rising from below 63% to close to 82% in 24 hours. While the Max Humidity showed only a slight increase from 96% to 98%, the Minimum Humidity values rose from 25% to 38%. Also, advancing the End of Season and shortening growing seasons in The Tropical Semi Evergreen Forest increased fire susceptibility. This study provides insight into the weather parameters that escalate forest fires.It will contribute to improving forest fire management and reducing the impact of future fire events especially in rich biodiversity areas such as the tropical evergreen and the semi-evergreen forest of Western Ghats
How to cite: vs, N. and chaturvedi, R. K.: Anthropogenic Ignition and Fire Weather Extremes: An Assessment of Meteorological Extremes Preceding the 2023 Central Western Ghats Forest Fire., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1373, https://doi.org/10.5194/egusphere-egu26-1373, 2026.
The large number of risk prediction indices implemented globally and the lack of a universally accepted and widely used general model for predicting fire behaviour highlight the fact that forecasting forest fires remains a complex problem. The fire phenomenon is changing because the forest environment and its interactions with the climate and society have new connotations. The fire season is increasingly longer, and extreme weather events such as heatwaves and droughts are more frequent, increasing water stress on vegetation, making it highly flammable. Fire management should consequently evolve to reflect new environmental scenarios (climate change, expansion of new forests, growth in urban populations and interface areas), implementing forest and land-use planning, including environmental education, decision support systems, and forest management. This observation leads to the awareness of the need to intensify study, analysis, and research activities and initiatives in this area.
In 2017 a large event involved the Vesuvius National Park (Campania, Italy) an area rich in natural resources, historic cradle of volcanology, breathtaking landscapes, crops, and centuries-old traditions. As part of the National Program "Italian Parks for the Climate" - Year 2020 - ", an innovative monitoring system, with the purpose to support a dynamic fire probability mapping and forest fire risk management, has been shared as an operational agreement between academia and stakeholders.
The project uses a combination of integrated, interdisciplinary, and interoperable modules to prepare the actions and interventions needed to prevent and reduce the risk of forest fires and the resulting hydrogeological risks (soil erosion, shallow landslides, and hyperconcentrated flows), enabling alerts and support the natural reserve operators. A "REMOTE" module, based on the analysis of small-scale space-time Sentinel data for land cover and soil moisture assessment is supported by a “TERRA” module, based on the installation, validation, expert control and interactive communication of an intelligent monitoring system for water, soil and meteorological station data, aimed at early warning of forest fires, complemented by the use of an object-oriented and environmentally focused data analysis of Tri-Stereo Neo imagery from the Pléiades imagery constellation (European Space Agency).
The monitoring program, launched in 2023 and still ongoing, has provided valuable data useful for the temporal dynamics of hydrological, climatic, and land cover variables that impact fire risk. Comparisons with fire events from 2023 to 2025 are being evaluated to test the forecasting capabilities that can be derived and put in practice to mitigate the wildfire risk.
How to cite: Longobardi, A., Guida, D., Giugliano, P., Cuomo, A., D'Ambrosio, R., Nicoletti, G., Palmiero, M. F., Pisani, M., and Cestari, A.: A monitoring system for wildfire risk assessment at Vesuvius National Park (Southern Italy), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18671, https://doi.org/10.5194/egusphere-egu26-18671, 2026.
In the context of increasingly frequent and intense wildfires, it is crucial to assess their long-term environmental consequences. While their short-term impacts on soil loss and sediment transport are well documented, their effects on erosion dynamics over broader spatial (e.g., watershed) and temporal (e.g., ≥20 years) scales have not been extensively studied. Most studies are restricted to short post-fire periods (i.e., on timescales comprised from a couple months to a decade), which limits our ability to evaluate the resilience, regeneration, and delayed responses of affected ecosystems.
To understand how ecosystems respond, adapt or degrade after wildfire events, it is essential to capture these dynamics over decadal timescales, both before and after such disturbances. In this context, sedimentary archives represent a powerful although underutilized tool for reconstructing past erosion processes and assessing the long-term (e.g., 20 years) resilience of ecosystems affected by wildfires.
This study focuses on the Peguières area, a complex of three small watersheds (13.5ha, 18ha and 39.8ha) located within the Esterel Massif in the French Mediterranean. These watersheds drain into three small artificial reservoirs, constructed in 1977, offering a unique opportunity to analyze sediment archives from three replicated, ecologically similar watersheds affected by major wildfires in 1987 and 2003. Given the minimal human impact in this Natura 2000 protected area, the recorded sediment signals are expected to be primarily influenced by wildfires, providing a robust means of reconstructing long-term erosion dynamics in Mediterranean fire-prone environments. The deployed analytical methodology, combining radionuclide analyses and clustering of geochemical parameters (Mn, Zr, Rb, Ca, Ti, etc.) with density data, provides a robust and reproducible framework for identifying distinct erosion phases before/during and after the wildfire within each core.
The Peguières site, as it comprises three micro-watersheds disturbed by wildfire, offers a unique opportunity to provide comparisons at the watershed scale. Preliminary findings from one of the watersheds, which burned completely during the 2003 wildfire, revealed that despite a general decline in erosion rates over time, erosion remained 31.15% higher in the recent period compared to pre-fire levels. These results challenge the assumption of full ecosystem resilience achievement within a decade after such a disturbance. These preliminary results demonstrate the value of sedimentary archives in assessing long-term impacts of wildfires. They can also inform the management of fire-prone landscapes and support the development of effective environmental protection strategies to mitigate soil and water resource degradation that may be caused by wildfires.
How to cite: Ducruet, R., Foucher, A., Chaboche, P.-A., and Evrard, O.: A 50-year Record of Soil Erosion Dynamics: Pre- and Post-Wildfire Observations from Sediment Coring Methods in Contrasting Ecosystems (Var, Southern France), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6449, https://doi.org/10.5194/egusphere-egu26-6449, 2026.
Surface wood shred treatments are used widely for post-fire erosion mitigation, and recent modelling has shown they are highly effective for debris flow mitigation; however, little attention has been given to their potential mobilisation and displacement under high-intensity rainfall events. Such movement could reduce treatment effectiveness, contaminate downstream water bodies, or contribute additional material to debris flows, should they initiate. Despite this recognised risk, significant knowledge gaps limit our ability to evaluate when and where treatment mobilisation may occur, and consequently, whether alternative post-fire treatments may be more suitable under some conditions.
The three key knowledge gaps that this study sought to address were: a) the stream power required to mobilise wood shred on hillslopes has not yet been quantified; b) there is no established method to determine the topographic and rainfall conditions under which sufficient stream power may be generated to mobilise wood shred in treated landscapes; and c) it is not yet possible to evaluate how the likelihood of shred mobilisation compares to the reduced likelihood of debris flow initiation resulting from treatment.
We addressed these knowledge gaps through a combination of field experiments and catchment-scale modelling. Field experiments were used to parameterise the relationship between hillslope stream power and wood shred displacement under channelised flow. A simple methodology was then developed to apply the stream power-based relationship at a 1 m resolution across a debris flow-prone landscape comprising headwaters with varying morphometric characteristics and under varying rainfall scenarios, to quantify the expected proportion of wood shred treatment mobilised. Finally, we estimated the likelihood of debris flow initiation with and without treatment, and the likelihood of treatment mobilisation, across ~400 zero-order basins with high post-fire hydrogeomorphic sensitivity in Melbourne’s key water supply catchment to evaluate the risk of wood shred mobilisation against the expected benefits of treatment.
Across the case-study water supply catchment, wood shred treatment is modelled to reduce the maximum likelihood (Annual Exceedance Probability [AEP], %) of debris flow initiation from 72% to 32%. However, we found that up to 40% of wood shred treatment would be mobilised before any treatment effect is realised, suggesting careful consideration of treatment risks and benefits is warranted. Nevertheless, even under a worst-case rainfall scenario (AEP < 0.01%), the mass of wood shred mobilised was 55 times lower than the modelled sediment load from debris flows triggered without treatment. This work provides critical insights for catchment managers evaluating potential post-fire erosion mitigation treatments and highlights the importance of considering the suitability of an area for treatment.
How to cite: Harrison, M., Smalley, F., Keeble, T., Lyell, C., Lane, P., and Sheridan, G.: Evaluating post-fire surface mulch treatments: Assessing hillslope stability and mobilisation potential relative to debris-flow mitigation effects, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18479, https://doi.org/10.5194/egusphere-egu26-18479, 2026.
Fire plays a significant role at the vegetation-soil-water interface, and its effects on soil properties and hydro-erosion dynamics have been widely investigated. However, fire effects on soil hydromechanical behavior and their relationship with increased susceptibility to shallow landslides remain poorly understood, particularly in tropical environments. In the mountainous region of Rio de Janeiro, Brazil, in the Nova Friburgo municipality, where an average of 316 fires occur per year, paleoenvironmental evidence indicates that shallow landslides preceded by wildfires occurred during the Holocene. To investigate fire-induced changes in soil hydromechanical properties, a field experiment applying controlled fire was conducted in 100 m² plots at the edge of a secondary Atlantic rainforest (RF) (October 2024) and in a homogenous grassland (GL) under antecedent grazing (September 2025). Flame temperature and soil temperatures were recorded at the surface, 5, and 10 cm depths. Adjacent unburned control plots were also established. Burned and unburned plots were outfitted with soil moisture sensors and soil suction sensors at different depths from surface to 150 cm. At burned RF, a tensiometer and additional suction sensors were also installed to improve measurement accuracy. In situ measurements of saturated hydraulic conductivity (Ksat) and soil water repellency were conducted at different instrumented depths. Laboratory analyses of texture, bulk density, Ksat, and soil water retention curves (SWRC) were conducted. To study the temporal changes of hydromechanical soil properties post-fire, measurements were investigated before burning and at successive post-fire intervals of 1 week, for selected parameters, 1 month, 6 months, and 1 year. Results from the flame temperature measurements during the experiment showed a non-uniform spatial distribution over time at both plots. While at RF burning experiment lasted for 2 hours with active flames, at GL the flames propagation lasted less than 10 minutes. Maximum soil temperatures at RF reached 361.5°C at the surface and 334.7°C at 5 cm depth, while at GL, surface temperature increased by approximately 50°C. At RF, in situ Ksat at 20 cm depth increased from 6.44 × 10-5 m s-1 before the fire to 1.51 × 10-4 m s-1 one week after burning, followed by a slow decrease over six months and one year, while no significant changes at greater depths (up to 150 cm) over the investigated time interval, or at any depth at GL were observed. Severe soil water repellency was detected at RF before burning, up to 10 cm depth, and progressively declined after fire, disappearing after six months, whereas no repellency was observed at GL. SWRC from both in situ and laboratory measurements indicated a reduction in volumetric water content at the saturation stage in the upper 20 cm at RF, with no changes at greater depths up to 150 cm and at all depths at GL. These findings will be used to improve the modelling of the post-fire hydromechanical soil behavior by integrating the in situ monitoring data and laboratory measurements, thereby enhancing the calibration of physically based models for shallow landslide susceptibility assessment.
How to cite: Bolsas, L., Coelho Netto, A. L., Capobianco, V., and Piciullo, L.: Fire-induced changes in soil hydromechanical properties and implications for shallow landslide triggering in southeastern Brazil, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14307, https://doi.org/10.5194/egusphere-egu26-14307, 2026.
Fire is increasingly recognized as a significant driver of trace metal mobility, posing risks to water quality, especially in metal-rich environments such as ultramafic wetlands. In such environments, wildfires can trigger the formation of Acid Sulfate Soils (ASS), further amplifying metal release [1]. This study investigates the geochemical processes controlling nickel (Ni) dynamics in such contexts, focusing on a burned doline and its downstream drinking water catchment on Île des Pins, New Caledonia.
Water chemistry analysis and advanced imaging techniques (SEM, TEM, XAS) reveal extreme post-fire dissolved Ni concentrations (up to 368,000 µg/L in the doline and 4,300 µg/L downstream), and transformation of the studied Gleysols into ASS. Those observations are interpreted as resulting from a multi-step reaction sequence: (1) oxidation of Ni-bearing pyrite and millerite due to increased oxygen diffusion, (2) acidification from sulfide oxidation, and (3) acidic dissolution of Ni-bearing chrysotile. This cascade scenario leads to the release of nickel, magnesium, and sulfate, which then precipitate as Ni-hexahydrite [(NixMg1-x)SO4.6H2O)] upon water evaporation.
Ni-hexahydrite, which is a highly soluble compound, accounts for 40–50% of the solid nickel in surface soils and drives the nickel dynamics at the soil-water interface and at catchment scale through repeated precipitation/dissolution cycles. These findings show that wildfires in ultramafic wetlands can severely mobilize trace metals via ASS formation, with metal-sulfates playing a crucial role in post-fire geochemical cycling.
[1] Thery G., Quantin C., Calmels D., Jeanpert J., Morin G., Montargès-Pelletier E., Bourbon E., Kessie M., Kieffer I., Genthon P., Juillot F., 2025. Nickel dynamics in acid sulfate soils formed after wildfires across ultramafic wetlands of New Caledonia: the key role of Ni-hexahydrite. Journal Soils and Sediments, doi.org/10.1007/s11368-025-04190-9
How to cite: Quantin, C., Thery, G., Calmels, D., Jeanpert, J., Morin, G., Montargès-Pelletier, E., Bourbon, E., Kessié, M., Kieffer, I., Genthon, P., and Juillot, F.: Post-fire nickel mobility in acid sulfate soils developed in ultramafic wetlands of New Caledonia, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7236, https://doi.org/10.5194/egusphere-egu26-7236, 2026.
Wildfires constitute one of the main agents of change in fire-prone landscapes. Beyond the immediate loss of vegetation and biodiversity, as well as the well-documented impacts on air and water quality, burned watersheds and hillslopes may trigger cascading geo-hydrological hazards in the weeks to years following a fire. Moreover, climate change is increasing the extent and intensity of wildfires, extending their impacts to territories with diverse geological and geomorphological characteristics, including high-altitude ecosystems with a greater extent of exposed rocky areas.
Despite extensive research on fire effects on vegetation and soils, knowledge gaps remain regarding the impact of wildfires on exposed rock outcrops and boulders directly affected by flames. In particular, little is known about how fire-induced thermal stress and accelerated rock weathering influence post-fire geo-hydrological processes. Much of the current understanding is based on qualitative observations rather than quantitative measurements, highlighting the need for systematic field-based studies to assess the effects of fire on rock materials.
This study presents field-based data collection and analysis from two case studies conducted over different post-fire periods. The first examines a short-term post-fire scenario following the 2025 Yeres wildfire affecting the Las Médulas Cultural Heritage Site (León, Spain), focusing on the assessment, sampling, and quantification of fire effects on rock materials using a hybrid methodological approach that integrates ecological sampling with non-destructive techniques (NDTs). The second case addresses mid-term fire effects after the 2023 Arafo wildfire (Tenerife, Spain) through a comprehensive inventory of slope instabilities and erosion processes triggered by the fire. Together, these complementary case studies provide an integrated framework for understanding both the direct and indirect impacts of wildfire processes operating at different temporal scales.
This work was developed within the framework of the CSIC Scientific Technical Advisory Group for Emergency Crises (GADE CSIC, Spain) and the project DINCAN (ref. 20125), funded under the 2024 Call for the Promotion of Scientific, Technological, and Innovation Culture (I+P) by the Spanish Foundation for Science and Technology (FECYT).
How to cite: Miranda, P., Rossi, M., Esposito, G., Fernández-Naranjo, Fco. J., Martínez-Martínez, J., Martínez-Corbella, M., García-Moreno, I., Pala, C., Ahlers, L., and Sarro, R.: Assessing Post-Fire Rock Weathering and Slope Instabilities in Fire-Prone Landscapes: Spanish Case Studies , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13074, https://doi.org/10.5194/egusphere-egu26-13074, 2026.
Within a Nationally funded National Interest Research Project (PRIN), named “Community Functional Structure effects on Mediterranean Ecosystem Functions. Assessing the relative role of woody community functional components and their interactions with ecological factors including disturbance” (PRIN CFS-MedEF), a set of indicators has been proposed and tested, to explore the functional pathways linking plant vascular biodiversity, climatic and disturbance factors (i.e., wildfire), and ecosystem functions involved in biogeochemical cycles such as net primary productivity and litter decomposition rate. Seldom were the extremely diverse and structurally complex Mediterranean forests studied. This complexity translates into a non-linear multivariate link between biodiversity, ecological factors and ecosystem functions. The methodological approach consists in testing in pairs of Mediterranean Quercus ilex and Q. suber forests in three regions (Latium, Calabria and Sardinia) the effects of climate, soil factors, and plant community functional structure on net primary productivity and litter decomposition rate. In detail, the functional community structure was calculated by Community Weighted Mean and Functional Diversity indexes. Standard protocols to collect and collate multidisciplinary data are being applied to assess the combined effect of all these variables, and to build the best explanatory model for predictors of the ecosystem functions considered. The novelty of the project consists in carrying out a detailed and simultaneous assessment of aboveground and belowground ecosystem functional dynamics, which was never performed in Italy. The results should contribute to the current scientific debate on the mechanisms through which Mediterranean forests respond to fire disturbance accounting also for environmental conditions providing useful insights for managing these ecosystems in view of the changes in climate and disturbance regime that will affect the Mediterranean regions globally.
How to cite: Jacomini, C., Bertini, L., Burrascano, S., Cogoni, D., Fenu, G., Gargano, D., Marabottini, R., Moscatelli, M. C., Ricotta, C., Vitale, M., and Varone, L.: Fire effects on soil and plant functional traits in Italian Mediterranean woodlands, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21991, https://doi.org/10.5194/egusphere-egu26-21991, 2026.
Fire has long been a central Earth system process in Australia, yet the influence of human land management on fire regimes over millennial timescales remains to be fully explored. In southeastern Australia, Indigenous cultural burning sustained fine-grained vegetation mosaics, reduced fuel continuity, and buffered ecosystems against extreme fire events for thousands of years. This study integrates palaeoecological and archaeological evidence to evaluate how the disruption of these practices following colonial settlement reshaped fire-vegetation-climate interactions and amplified fire risk.
Using pollen-based land-cover reconstructions, sedimentary charcoal, archaeological demographic models, we reconstruct spatiotemporal patterns of fire activity through deep time, from 125,000 years ago to the post-colonial period. Our analyses reveal that fuel connectivity reached their lowest levels during the Mid to Late Holocene (ca. 6,000 years cal BP), coinciding with intensification of cultural burning. These stable low-fuel mosaics contrast sharply with the rapid fuel build-up that followed colonial suppression of Indigenous burning in the past two centuries.
We further demonstrate that the transition to post-colonial land management, characterised by fire exclusion, pastoral expansion, and vegetation thickening, created conditions that now interact with anthropogenic climate change to elevate the probability and severity of extreme fire events.
By providing long-term baselines for fire regimes, fuel structures, and human–environment feedbacks, our findings highlight how the loss of Indigenous fire stewardship has fundamentally altered fire risk in southeastern Australia. This historical perspective offers crucial insights for contemporary fire mitigation strategies and the re-establishment of resilient, culturally informed land management under a rapidly warming climate. These insights also resonate with fire-prone regions worldwide where the interruption of Indigenous cultural burning has similarly reshaped fuel dynamics and wildfire behaviour, underscoring the global value of revitalising Indigenous fire stewardship.
How to cite: Mariani, M., Wills, A., Connor, S., Cadd, H., Adeleye, M., Stevenson, J., Herbert, A., Florin, A., Mooney, S., Fletcher, M.-S., Bowman, D., Theuerkauf, M., Kershaw, P., and Haberle, S.: Tracing fuels for fire through time: from Indigenous cultural burning to colonial land management in Australia, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1790, https://doi.org/10.5194/egusphere-egu26-1790, 2026.
