Burn Severity Research Articles

Analysing the capacity of multispectral indices to map the spatial distribution of potential post-fire soil losses based on soil burn severity

The area burned in Spain exceeded historical records in 2022, when exceptionally warm conditions influenced wildfire events. The predicted intensification of wildfire regimes includes an increase in frequency, severity, and size. Therefore, a study of the wildfires that occurred in 2022 is necessary to understand their behaviour and possible environmental impacts. The objective of this study is to analyse the applicability of using spectral indices and Geographic Information System (GIS) approaches to map the spatial distribution and estimate potential soil losses using Sentinel-2 imagery and fire severity field data. Soil losses were estimated using an empirical model based on soil burn severity data collected in the field after wildfire. The relationship between the Normalized Difference Infrared Index (NDII), Difference Normalized Wildfire Ash Index (dNWAI), and the Blue Normalized Difference Vegetation Index (BNDVI) with the estimated soil losses was then evaluated. In addition, the influence of different time scales of the satellite images was analysed. The first period considered (Date I) ranges from 8 to 20 days after the beginning of the wildfire, which coincides with the field data collection. The second period considered (Date II) ranges from 28 to 35 days after the start of the wildfire. The results obtained showed a significant dependence relationship between the BNDVI index (using satellite images of Date I) and the estimated soil losses (R2 = 0.756), while the results of the NDII (R2 = 0.31) and dNWAI (R2 = 0.061), showed no spatial relationship with the estimated soil losses. Three of the largest wildfires in 2022 in Spain were analysed, and the results showed strong correlations of BNDVI index for Folgoso do Courel (R2 = 0.808), for Carballeda de Valedorras (R2 = 0.906), and for Sierra de la Culebra (R2 = 0.939). In addition, these results allowed the mapping and quantification of potential soil losses in areas where fire severity was high, totalling ∼2,50,000 Mg ha−1 in Folgoso do Courel, ∼3,70,000 Mg ha−1 in Carballeda de Valdeorras, and ∼4,70,000 Mg ha−1 in Sierra de la Culebra. Moreover, BNDVI values for estimating soil loss vary by vegetation type, and there is a positive correlation between severity classes and the BNDVI index. This approach can inform post-fire land management decisions in future wildfires and could be applied to other regions.

Train Climbing-A new old trend in adolescents: Treatment of high voltage injuries and planning of a pilot project to raise awareness.

An increasing number of high voltage electric burn injuries in atypically younger patient collective of train surfers and climbers at our levelI center for burns was recognized. The purpose of this study was aretrospective data evaluation and as aconsequence the implementation of an awareness program against train surfing. In aretrospective analysis of prospectively collected data, 17patients with high voltage injuries, who had been treated at our unit between January 2022 and January 2023, were identified. Of these patients seven were treated for injuries due to train surfing or climbing and therefore included in this study. The patients were assessed clinically for total burn surface area (TBSA), degree of burn, associated Injuries, hospital length of stay, number and type of surgeries (fasciotomy, minor/major amputations, defect coverage split skin graft or flaps). Atotal of seven males formed the basis of this report with an average age of 17.7 years (range 14-21years). The highest ABSI (Abbreviated Burn Severity Index) score was 12, leading to the death of the 21-year-old patient who had 80% TBSA as well as multiple comorbidities including severe brain damage. The mean duration of stay at the intensive care unit (ICU) was 24.8 days and the mortality rate was 14.29%. This study highlighted the severity of injuries, with amean TBSA of 41.42% and amortality rate of 14.29% among the study population. Train climbing and surfing patients presented with severe injuries and fatal long-term consequences. Apilot project involving several stakeholders was initiated in order to raise awareness of the dangers of electric arcs and the risk involved.

Steady-state versus burst lasing techniques for thulium fiber laser

ObjectiveTo evaluate the stone ablation rate and direct thermal damage from thulium fiber laser (TFL) lithotripsy using continuous (C) and burst (B) lasing techniques on an in vitro ureteral model.MethodsThe TFL Drive (Coloplast, Humlebaek, Denmark) was used in an in vitro saline-submerged ureteral model. Ten participants, including five junior and five experienced urologists, conducted the experimental setup with 7 different settings comparing two lasing techniques: steady-state lasing (0.5 J/10 Hz = 5W for 300 s and 0.5 J/20 Hz = 10W for 150 s) and burst, intermittent 5 s on/off lasing (0.5 J/20 Hz, 0.5 J/30 Hz, 0.5 J/60 Hz, 0.1 J/200 Hz, and 0.05 J/400 Hz) with a target cumulative energy of 1500 J using cubic 125 mm3 phantom BegoStonesTM. Ureteral damage was graded 1–3 based on the severity of burns and holes observed on the surface of the ureteral model.ResultsThe were no significant differences in stone ablation mass neither between C and B lasing techniques, nor between expertise levels. At C lasing technique had only mild ureteral lesions with no significant differences between expertise levels (p: 0.97) or laser settings (p: 0.71). At B lasing technique, different types of thermal lesions were found with no expertise (p: 0.11) or setting (p: 0.83) differences. However, B laser setting had higher grade direct thermal lesions than C (p: 0.048).ConclusionRegarding efficacy, C and B lasing techniques achieve comparable stone ablation rates. Safety-wise, B lasing mode showed higher grade of direct thermal lesions. These results should be further investigated to verify which of the lasing mode is the safest in vivo. Until then and unless proven otherwise, a C mode with low frequency should be recommended to avoid ureteral wall lesions.

Wildfire Threshold Detection and Progression Monitoring Using an Improved Radar Vegetation Index in California

To address the recent increase in wildfire severity and incidence, as well as the subsequent financial and physical costs, forest managers and wildland firefighting agencies rely on remotely sensed products for better decision-making and mitigation efforts. To address the remote sensing needs of these agencies, which include high spatial resolution, immunity to atmospheric and solar illumination effects, and day/night capabilities, the use of synthetic aperture radar (SAR) is under investigation for application in current and upcoming systems for all phases of a wildfire. Focusing on the active phase, a method for monitoring wildfire activity is presented based on changes in the radar vegetation index (RVI). L-band backscatter measurements from NASA/JPL’s UAVSAR instrument are used to obtain RVI images on multiple dates during the 2020 Bobcat (located in Southern CA, USA) and Hennessey (located in Northern CA, USA) fires and the 2021 Caldor (located in the Sierra Nevada region of CA, USA) fire. Changes in the RVI between measurement dates of a single fire are then compared to indicators of fire activity such as ancillary GIS-based burn extent perimeters and the Landsat 8-based difference normalized burn ratio (dNBR). An RVI-based wildfire “burn” detector/index is then developed by thresholding the RVI change. A combination of the receiver operating characteristic (ROC) curves and F1 scores for this detector are used to derive change detection thresholds at varying spatial resolutions. Six repeat-track UAVSAR lines over the 2020 fires are used to determine appropriate threshold values, and the performance is subsequently investigated for the 2021 Caldor fire. The results show good performance for the Bobcat and Hennessey fires at 100 m resolution, with optimum probability of detections of 67.89% and 71.98%, F1 scores of 0.6865 and 0.7309, and Matthews correlation coefficients of 0.5863 and 0.6207, respectively, with an overall increase in performance for all metrics as spatial resolution becomes coarser. The results for pixels identified as “burned” compare well with other fire indicators such as soil burn severity, known progression maps, and post-fire agency publications. Good performance is also observed for the Caldor fire where the percentage of pixels identified as burned within the known fire perimeters ranges from 37.87% at ~5 m resolution to 88.02% at 500 m resolution, with a general increase in performance as spatial resolution increases. All detections for Caldor show dense collections of burned pixels within the known perimeters, while pixels identified as burned that lie outside of the know perimeters have a sparse spatial distribution similar to noise that decreases as spatial resolution is degraded. The Caldor results also align well with other fire indicators such as soil burn severity and vegetation disturbance.

Post-wildfire boreal forest vegetation cover change mapping via information fusion for secondary disaster risk assessments

Post-wildfire vegetation cover damage and loss can escalate the risks of secondary disasters such as flood, landslide, and water contamination, particularly in a major wildfire affected region where human settlements are situated. In assessments of the secondary disaster risks, the post-wildfire vegetation cover change plays a key role in influencing the distribution and intensity of the risks. In this work, a processing framework for mapping post-wildfire vegetation cover changes through information fusion has been generated and tested using Landsat8 and WorldView imagery data. The test site was the boreal forest region surrounding Fort McMurray, Alberta, Canada, affected by a massive wildfire in May 2016. The derived map results indicate that the fusion process in the framework is effective for generation of post-wildfire vegetation cover change information. The use of WorldView data revealed more variation details in distribution of the vegetation cover burn damages than use of Landsat data. Moreover, the uncertainty in vegetation burn severity using Landsat-based Differenced Normalized Burn Ratio (dNBR) index exists in the areas with low dNBR reading values due to the sub-pixel effect. The forest burn severity measured with dNBR index can be underestimated due to the quick herbaceous cover recovery after wildfire. These uncertainties in the post-wildfire vegetation cover mapping should be taken into consideration when the derived information is being used for risk assessments.

Retrospective Study of the Epidemiological-Clinical Characteristics of Burns Treated in a Hospital Emergency Service (2018-2022).

Burns are a common and severe medical emergency requiring immediate specialized care to minimize damage and prevent complications. Burn severity depends on depth, extent, and location, with more complex care needed for burns on critical areas or extensive burns. Nursing is essential in burn management, providing immediate care, adapting treatments, managing pain, preventing infections, and offering emotional support for recovery. The study aims to analyse the epidemiological and clinical characteristics of burns treated at the Hospital Emergency Department of the Hospital Complex of Cáceres (Spain) from January 2018 to December 2022. It looks at factors like gender, age, hospital stay duration, emergency type (paediatric or adult), main diagnosis, skin thickness, burn degree, affected body areas, percentage of body surface area burned, and treatment types. It also investigates how treatment varies by gender, age, skin thickness, and burn severity. The relevance of this research lies in the fact that periodic epidemiological studies are essential to monitor changes in diseases, evaluate the effectiveness of interventions, detect outbreaks quickly, update knowledge on risk factors, and guide health policy decisions. This ensures an adapted and effective response to the needs of the population. Retrospective, observational study that analysed burn cases treated at the Hospital Complex of Cáceres (Spain) 2018-2022. Inclusion criteria were based on ICD-10 codes for burns, excluding severe cases not treated in this service. Data were analysed using descriptive statistics, Student's t-tests, Chi-square tests, and ANOVA. 220 patients surveyed, with a mean age of 47 years and 60.9% male. Most burns (95.5%) affected the external body surface, with a mean hospital stay of 7.86 days. Medical treatment was provided to 75.5% of patients, and 24.5% required surgical intervention. Significant differences in treatment procedures were observed according to age, skin thickness, and burn degree. Older patients had more procedures and longer hospital stays. Excision and transfer procedures were more common in full-thickness and severe burns. The findings align with previous research on burn demographics and treatment approaches. Treatment differences by age and burn severity highlight the need for tailored interventions. The study underscores the importance of comprehensive burn management, including psychological support for improved long-term outcomes. Further research could explore the impact of socio-economic factors on burn incidence and treatment. This study was not registered.

Graft take outcomes of burn patients transplanted with CEA derived from a modified composite culture technique: A case series.

Low-cost and efficient culture environments comparable to standard techniques would undoubtedly improve burn outcomes in under-resourced settings. The aim of this case series was to report on the CEA graft-take using a modified composite culture technique. CEA transplants, following emergency ethical approval, occurred for burn patients (n=25) with low survival prognosis and/or exhausted donor sites. Keratinocytes were retrieved from skin biopsies, seeded centrally on routinely-used dressing gauze and incubated at 37 °C in pediatric incubators. Fresh autogenous plasma was applied daily and hydrogel every third or fourth day. After confluence, the CEA was transplanted onto debrided wound beds. Xenografts were used for temporary cover during the culture period. Final graft take assessment (21 days) was assessed and calculated as a graft take percentage for total CEA area transplanted. Central indices were described as mean (95% CI) and frequency (%) for age, total body surface area, abbreviated burn severity index scores, survival prognosis and graft take. Eleven patients survived with a mean age of 36.1 years (95% CI 25.8-46.4), 45.0 %TBSA burns (95% CI 35.1-54.9), 9.7 ABSI scores (95% CI 8.6-10.8) and 79.5% graft take (95% CI 62.9-96.0). Reduced graft take (61.2%) was observed in patients with perineum burns and increased graft take (97%) in uncomplicated burns. The average CEA graft take was 79.5% using a low-cost culture technique and comparable to the largest case series in literature. The survival of the major burn cases was highly favourable considering injury severity, expected outcomes without CEA and the observed challenges.

Long-Term Cumulative Effects of Wildfires on Soil-Vegetation Dynamics in the “Baixa Limia–Serra do Xurés” Natural Park

Wildfires are recognized as major contributors to forest loss and soil degradation on a global scale. Understanding the cumulative effects of fire regimes on forest ecosystems and soil dynamics necessitates a deeper exploration of wildfire-vegetation-soil interactions over the long term. This study delves into the wildfire-landscape dynamics within the “Baixa Limia Serra do Xurés” Natural Park, a region prone to fires in Galicia, Spain. By analyzing available statistical and remote sensing data, we identified significant shifts in fire regimes and landscape dynamics between the periods of 2000–2010 and 2010–2020. Our findings indicate a potential extension of the fire season, reflecting the impacts of climate change. Despite improvements in firefighting capabilities, the occurrence of large fires is on the rise in the Natural Park, underscoring the need for proactive management strategies in such areas. Notably, significant fire events in 2011, 2016, 2017, and 2020 extensively affected wooded areas, constituting the majority of the burned area. Shrubs and forests emerged as particularly vulnerable, with varying degrees of burn severity influencing post-fire vegetation recovery rates. While shrublands expanded their coverage between 2000 and 2010, rocky areas with sparse vegetation showed an increase over the subsequent decade (2010–2020), indicating soil degradation and potential desertification in areas affected by recurrent and severe fires, especially within zones designated for the highest levels of protection (with fire rotation periods of less than 1 year). In conclusion, this study provides valuable insights into the impacts of wildfires, changes in land cover, and post-fire soil-vegetation dynamics, which can inform management and conservation efforts in fire-prone mountainous regions. Leveraging advanced remote sensing techniques enables the monitoring of cumulative soil degradation resulting from repeated wildfires over extended periods.

Associated bacterial and fungal infections in burn wounds: Common factors, distribution in etiology, age groups, bacterial and fungal strands – Evaluation of a single burn center experience of 20 years

IntroductionBurn intensive care unit (BICU) patients suffer from reduced immunological competence. Often bacterial and fungal infections occur as single or associated infection of the burn site. However, common factors in associated infections are discussed controversially. In this study we evaluated factors common in associated occurrence of bacterial and fungal infection in the burn population. Patients and methodsIn total 213 patients, admitted to the ICU of Cologne Merheim Clinical Center between 1988 and 2011, with associated infections were included in this study. Exclusion criteria were no bacterial, or no fungal infection, or incomplete data. Data evaluated were sex, age, type of burn injury, total body surface area (TBSA), abbreviated burn severity index (ABSI) score, 3rd degree burn, inhalation injury, length of BICU stay, antibiotic therapy, bacterial strand, fungal strand, incidence of bacteria and fungus infection, single or associated occurrence and bacteria species associated with fungus species. Statistical analysis comprised of univariate, Chi-square and Fischer Exact test, multivariate analysis, positive and negative predictive value, logistic regression analysis with the Nagelkerke, Cox/ Snell R-square. Results196 patients were included into the study, 147 male and 49 female. Total mean age was 47 years, in the fire burn group 47 years, in scalding 53 years, in electrical burn 29 years and in chemical burn 62 years. 123 male and 45 female were combusted, 15 male and 3 female scalded, 9 male had an electrical burn and 1 female a chemical burn. The mean TBSA in fire burns was 41 %, in scalding 42 %, in electrical burns 46 %, and in chemical burn 16 %. The mean ABSI in fire burn and scalding was 9, in electrical burn 8 and in chemical burn 7. The 3rd degree burns were 16 % in fire burn and 13 % in scalding and electrical burn and 0 % in chemical burn. The length of BICU stay was 49 days for fire burn, 47 days for scalding, 58 days in electrical burn and 21 days in chemical burn patients.The gram-positive bacterial strands most often found were Staphylococcus strands, gram negative Pseudomonas and Acinetobacter strands. Candida albicans was the most often present fungal strand. There was no difference in incidence between gram positive and gram-negative bacteria. In patients suffering from fire burns the most common bacteria were Staphylococcus and Pseudomonas, in scalding Acinetobacter, and in chemical burns Staphylococcus. In electrical burns no predominant bacterial strand was found. The associated occurrence of Staphylococcus and Candida albicans and Pseudomonas and Candida albicans was predominant. In patients with fire burn, 48% showed an associated infection, in scalding 21%, in electrical burn 33% and in chemical burn 100%.Combusted patients had the highest incidence of associated infection in age group 80–89 years, in scalding 40–49, 50–59 and 70–79 years, in electrical burn 20–29 years and in chemical burn 60–69 years. Most common factors of associated infections were higher age, high TBSA with 3rd degree burns and bacterial infections. Interestingly inhalation injury was highly inversely correlated to associated infection. ConclusionThe associated occurrence of bacterial and fungal wound infection is highest in burn patients with infections with Staphylococcus or Pseudomonas, the incidence is mainly found in fire burn and electrical burns. The use of oxygen in inhalation injury might prevent associated bacterial and fungal infections.

Predictive Understanding of Links Between Vegetation and Soil Burn Severities Using Physics‐Informed Machine Learning

AbstractBurn severity is fundamental to post‐fire impact assessment and emergency response. Vegetation Burn Severity (VBS) can be derived from satellite observations. However, Soil Burn Severity (SBS) assessment—critical for mitigating hydrologic and geologic hazards—requires costly and laborious field recalibration of VBS maps. Here, we develop a physics‐informed Machine Learning model capable of accurately estimating SBS while revealing the intricate relationships between soil and vegetation burn severities. Our SBS classification model uses VBS, as well as climatological, meteorological, ecological, geological, and topographical wildfire covariates. This model demonstrated an overall accuracy of 89% for out‐of‐sample test data. The model exhibited scalability with additional data, and was able to extract universal functional relationships between vegetation and soil burn severities across the western US. VBS had the largest control on SBS, followed by weather (e.g., wind, fire danger, temperature), climate (e.g., annual precipitation), topography (e.g., elevation), and soil characteristics (e.g., soil organic carbon content). The relative control of processes on SBS changes across regions. Our model revealed nuanced relationships between VBS and SBS; for example, a similar VBS with lower wind speeds—that is, higher fire residence time—translates to a higher SBS. This transferrable model develops reliable and timely SBS maps using satellite and publicly accessible data, providing science‐based insights for managers and diverse stakeholders.

Role of the revised Baux score in predicting mortality among burn patients in an African low-income country: a multicentre prospective cohort.

Burn injury is a major cause of mortality. Majority of the burns occur in low and middle-income countries like Uganda. Uganda has a limited number of burn centres and medical resources, making a predictor of mortality necessary in allocation of the limited resources. Although the revised Baux (r-Baux) score has been validated and used in many high income countries, no study has assessed its role in an African low-income country; the reason this study was done. This was a prospective multicentre cohort that enroled 101 burn patients with moderate and severe burns admitted in three tertiary hospitals in western Uganda. Follow-up was done until discharge, documenting mortality. A receiver operator characteristic curve was used to determine the role of r-Baux score in predicting mortality. This study included 101 patients, with a mean age of 21.3 (SD=16.8) years. The majority of the participants were male (69.3%). The area under the curved for r-Baux score's prediction of mortality was 0.943 (P<0.001). The most appropriate cut-off was determined to be 74.5. At this cut-off, r-Baux score predicted mortality with a sensitivity of 100% and specificity of 83.5%. After controlling for burn severity using Poisson regression, a patient with r-Baux score greater than 74.5 was 1.358 times more likely to die (adjusted risk ratio=1.358, 95% CI=1.195-1.543, P<0.001). The r-Baux score was found to be excellent at predicting mortality among burn patients in Uganda and therefore should be done for all patients at admission, in order to predict mortality and do proper planning.

Machine learning approach to burned area mapping for Southern California

ABSTRACT Accurate representation of the location and amount of burned areas is vital to the understanding of patterns and impacts of fires. Some extant burned area maps appear to have high commission errors, which lead to an overrepresentation of burned area. The primary research objective of this study was to assess whether region-specific training data used for machine learning routines improve accuracy of burned area products for western San Diego County. We used training data derived from fine-scale aerial orthoimagery to create and compare three training sets, each with a different Landsat scale sub-pixel burn threshold: 20%, 50%, or 80%. Meaning either 20%, 50%, or 80% of a 30 m × 30 m pixel had to burn for the entire pixel to be classified as burned. High-resolution orthoimagery was used for the creation of the training/testing data as well as determining which sub-pixel threshold leads to more accurate burned area representation. These training data were input into a gradient-boosted regression model. We compared the burned area product from the region-specific gradient boosted model (L-GBRM) to the three products: Monitoring Trends in Burn Severity, Fire and Resource Assessment Program, and the Landsat Burned Area product. We found >20% sub-pixel burn threshold of a Landsat pixel yielded the most accurate classification results. We used a 50% sub-pixel burn threshold for the reference data to compare the results to since the burned area associated with it is closely aligned with the high-resolution orthoimagery determined burn area. The L-GBRM was the most accurate product while also mapping the smallest area burned, suggesting that the extant products have relatively high commission errors. Using region-specific training data achieved a higher accuracy than nationwide training data. Looking at sub-pixel burn thresholds for creating a burned area map could prove to make a more accurate map in terms of area burned represented.

Wildfires Influence Mercury Transport, Methylation, and Bioaccumulation in Headwater Streams of the Pacific Northwest.

The increasing frequency and severity of wildfires are among the most visible impacts of climate change. However, the effects of wildfires on mercury (Hg) transformations and bioaccumulation in stream ecosystems are poorly understood. We sampled soils, water, sediment, in-stream leaf litter, periphyton, and aquatic invertebrates in 36 burned (one-year post fire) and 21 reference headwater streams across the northwestern U.S. to evaluate the effects of wildfire occurrence and severity on total Hg (THg) and methylmercury (MeHg) transport and bioaccumulation. Suspended particulate THg and MeHg concentrations were 89 and 178% greater in burned watersheds compared to unburned watersheds and increased with burn severity, likely associated with increased soil erosion. Concentrations of filter-passing THg were similar in burned and unburned watersheds, but filter-passing MeHg was 51% greater in burned watersheds, and suspended particles in burned watersheds were enriched in MeHg but not THg, suggesting higher MeHg production in burned watersheds. Among invertebrates, MeHg in grazers, filter-feeders, and collectors was 33, 48, and 251% greater in burned watersheds, respectively, but did not differ in shredders or predators. Thus, increasing wildfire frequency and severity may yield increased MeHg production, mobilization, and bioaccumulation in headwaters and increased transport of particulate THg and MeHg to downstream environments.

Severity and Clinical Outcomes of Pediatric Burns-A Comprehensive Analysis of Influencing Factors.

(1) Background: Burn injuries in children present a significant public health concern due to their potential for severe physical and psychological impact. (2) Methods: This study investigates the determinants of pediatric burn severity by analyzing the interplay of demographic and environmental factors. Through a retrospective analysis of pediatric burn cases over five years, encompassing patient demographics, burn causative agents, and clinical outcomes, this research aims to identify significant predictors of burn severity. (3) Results: This study presents a comprehensive analysis of pediatric burn injuries, focusing on the severity, clinical outcomes, and multifactorial aspects influencing recovery. We reviewed 1498 pediatric burn cases from January 2015 to December 2020. The mean age of patients was 5.8 years, with a slight male predominance (54%). Scalds (45%), flame burns (30%), and contact burns (15%) were the most common burn types. Our findings indicate significant differences in burn severity based on TBSA, with 32.5% of cases having TBSA greater than 20%. Multivariate logistic regression identified rural residence, male gender, flame burns, and lower socioeconomic status as significant predictors of severe burn outcomes. The overall mortality rate was 2.5%, with higher rates among patients with TBSA greater than 40%. These results highlight the need for targeted prevention strategies and improved access to specialized burn care. (4) Conclusions: Understanding these factors can inform targeted prevention strategies and improve treatment protocols.

Multidecadal vegetation transformations of a New Mexico ponderosa pine landscape after severe fires and aerial seeding.

Wildfires and climate change increasingly are transforming vegetation composition and structure, and postfire management may have long-lasting effects on ecosystem reorganization. Postfire aerial seeding treatments are commonly used to reduce runoff and soil erosion, but little is known about how seeding treatments affect native vegetation recovery over long periods of time, particularly in type-converted forests that have been dramatically transformed by the effects of repeated, high-severity fire. In this study, we analyze and report on a rare long-term (23-year) dataset that documents vegetation dynamics following a 1996 post-fire aerial seeding treatment and a subsequent 2011 high-severity reburn in a dry conifer landscape of northern New Mexico, USA. Repeated surveys between 1997 and 2019 of 49 permanent transects were analyzed for differences in vegetation cover, richness, and diversity between seeded and unseeded areas, and to characterize the development of seeded and unseeded vegetation communities through time and across gradients of burn severity, elevation, and soil-available water capacity. Seeded plots showed no significant difference in bare ground cover during the initial years postfire relative to unseeded plots. Postfire seeding led to a clear and sustained divergence in herbaceous community composition. Seeded plots had a much higher cover of non-native graminoids, primarily Bromus inermis, a likely contaminant in the seed mix. High-severity reburning of all plots in 2011 reduced native graminoid cover by half at seeded plots compared with both prefire levels and with plots that were unseeded following the initial 1996 fire. In addition, higher fire severity was associated with increased non-native graminoid cover and reduced native graminoid cover. This study documents fire-driven ecosystem transformation from conifer forest into a shrub-and-grass-dominated system, reinforced by aerial seeding of grasses and high-severity reburning. This unique long-term dataset illustrates that post-fire seeding carries significant risks of unwanted non-native species invasions that persist through subsequent fires-thus alternative postfire management actions merit consideration to better support native ecosystem resilience given emergent climate change and increasing disturbance. This study also highlights the importance of long-term monitoring of postfire vegetation dynamics, as short-term assessments miss key elements of complex ecosystem responses to fire and postfire management actions.

The influence of burn severity on dissolved organic carbon concentrations across a stream network differs based on seasonal wetness conditions

Abstract. Large, high-severity wildfires in many regions across the globe have increased concerns about their impacts on carbon cycling in watersheds. Altered sources of carbon and changes in catchment hydrology after wildfire can lead to shifts in dissolved organic carbon (DOC) concentrations in streams, which can have negative impacts on aquatic ecosystem health and downstream drinking-water treatment. Despite its importance, post-fire DOC responses remain relatively unconstrained in the literature, and we lack critical knowledge of how burn severity, landscape elements, and climate interact to affect DOC concentrations. To improve our understanding of the impact of burn severity on DOC concentrations, we measured DOC at 129 sites across a stream network extending upstream, within, and downstream of a large, high-severity wildfire in Oregon, USA. We collected samples across the study sub-basin during four distinct seasonal wetness conditions. We used our high-spatial-resolution data to develop spatial stream network (SSN) models to predict DOC across the stream network and to improve our understanding of the controls on DOC concentrations. Spatially, we found no obvious wildfire signal – instead, we observed a pattern of increasing DOC concentrations from the high-elevation headwaters to the sub-basin outlet, while the mainstem maintained consistently low DOC concentrations. This suggests that effects from large wildfires may be “averaged” out at higher stream orders and larger spatial scales. When we grouped DOC concentrations by burn severity group, we observed a significant decrease in the variability of DOC concentrations in the moderate and high burn severity sub-catchments. However, our SSN models were able to predict decreases in DOC concentrations with increases in burn severity across the stream network. Decreases in DOC concentrations were also highly variable across seasonal wetness conditions, with the greatest (−1.40 to −1.64 mg L−1) decrease occurring in the high-severity group during the wetting season. Additionally, our models indicated that in all seasons, baseflow index was more influential in predicting DOC concentrations than burn severity was, indicating that groundwater discharge can obscure the impacts of wildfire in a stream network. Overall, our results suggested that landscape characteristics can regulate the DOC response to wildfire. Moreover, our results also indicated that the seasonal timing of sampling can influence the observed response of DOC concentrations to wildfire.

A global forest burn severity dataset from Landsat imagery (2003–2016)

Abstract. Forest fires, while destructive and dangerous, are important to the functioning and renewal of ecosystems. Over the past 2 decades, large-scale, severe forest fires have become more frequent globally, and the risk is expected to increase as fire weather and drought conditions intensify. To improve quantification of the intensity and extent of forest fire damage, we have developed a 30 m resolution global forest burn severity (GFBS) dataset of the degree of biomass consumed by fires from 2003 to 2016. To develop this dataset, we used the Global Fire Atlas product to determine when and where forest fires occurred during that period and then we overlaid the available Landsat surface reflectance products to obtain pre-fire and post-fire normalized burn ratios (NBRs) for each burned pixel, designating the difference between them as dNBR and the relative difference as RdNBR. We compared the GFBS dataset against the Canada Landsat Burned Severity (CanLaBS) product, showing better agreement than the existing Moderate Resolution Imaging Spectrometer (MODIS)-based global burn severity dataset (MOdis burn SEVerity, MOSEV) in representing the distribution of forest burn severity over Canada. Using the in situ burn severity category data available for the 2013 wildfires in southeastern Australia, we demonstrated that GFBS could provide burn severity estimation with clearer differentiation between the high-severity and moderate-/low-severity classes, while such differentiation among the in situ burn severity classes is not captured in the MOSEV product. Using the CONUS-wide composite burn index (CBI) as a ground truth, we showed that dNBR from GFBS was more strongly correlated with CBI (r=0.63) than dNBR from MOSEV (r=0.28). RdNBR from GFBS also exhibited better agreement with CBI (r=0.56) than RdNBR from MOSEV (r=0.20). On a global scale, while the dNBR and RdNBR spatial patterns extracted by GFBS are similar to those of MOSEV, MOSEV tends to provide higher burn severity levels than GFBS. We attribute this difference to variations in reflectance values and the different spatial resolutions of the two satellites. The GFBS dataset provides a more precise and reliable assessment of burn severity than existing available datasets. These enhancements are crucial for understanding the ecological impacts of forest fires and for informing management and recovery efforts in affected regions worldwide. The GFBS dataset is freely accessible at https://doi.org/10.5281/zenodo.10037629 (He et al., 2023).

Stream chemical response is mediated by hydrologic connectivity and fire severity in a Pacific Northwest forest

AbstractLarge‐scale wildfires are becoming increasingly common in the wet forests of the Pacific Northwest (USA), with predicted increases in fire prevalence under future climate scenarios. Wildfires can alter streamflow response to precipitation and mobilize water quality constituents, which pose a risk to aquatic ecosystems and downstream drinking water treatment. Research often focuses on the impacts of high‐severity wildfires, with stream biogeochemical responses to low‐ and mixed‐severity fires often understudied, particularly during seasonal shifts in hydrologic connectivity between hillslopes and streams. We studied the impacts of the 2020 Holiday Farm Fire at the HJ Andrews Experimental Forest where rare pre‐fire stream discharge and chemistry data allowed us to evaluate the influence of mixed‐severity fire on stream water quantity and quality. Our research design focused on two well‐studied watersheds with low and low‐moderate burn severity where we examined long‐term data (pre‐ and post‐fire), and instantaneous grab samples collected during four rain events occurring immediately following wildfire and a prolonged dry summer. We analysed the impact of these rain events, which represent the transition from low‐to‐high hydrologic connectivity of the subsurface to the stream, on stream discharge and chemistry behaviour. Long‐term data revealed total annual flows and mean flows remained fairly consistent post‐fire, while small increases in baseflow were observed in the low‐moderately burned watershed. Stream water concentrations of nitrate, phosphate and sulfate significantly increased following fire, with variance in concentration increasing with fire severity. Our end member mixing models suggested that during rain events, the watershed with low‐moderate severity fire had greater streamflow inputs from soil water and groundwater during times of low connectivity compared to the watershed with low severity fire. Finally, differences in fire severity impacts on concentration‐discharge relationships of biogenic solutes were most expressed under low catchment connectivity conditions. Our study provides insights into post‐wildfire impacts to stream water quality, with the goal of informing future research on stream chemistry responses to low, moderate and mixed severity wildfire.

The association between neighborhood disadvantage and patient-reported outcomes in burn survivors

BackgroundBurns can cause long-term complications including pain and poor physical function. While neighborhood disadvantage is associated with burn severity, its effect on long-term complications has not been investigated. We hypothesized that patients from areas of higher area of deprivation index (ADI) will report poorer long-term outcomes. MethodsWe linked patient data from the Burn Model System with ADI state decile (1 = least, 10 = most disadvantaged) using year and residence at time of injury. We performed bivariate analyses to identify associations between ADI and patient and burn characteristics and multivariate regressions to determine whether ADI was associated with PROMIS-29 pain and physical function 6- and 24-months post-burn. ResultsWe included 780 patients; 69 % male, median age = 46 years, median ADI = 6, and median TBSA = 8 %. Multivariate regressions adjusting for TBSA, race, age, sex, anxiety, depression, and pain interference demonstrated that higher ADI was a significant predictor of higher pain intensity 6- (p = 0.001) and 24-months (p = 0.037) post-burn but not worse physical function 24-months post-burn (p = 0.089). ConclusionsHigher neighborhood disadvantage was associated with higher long-term pain intensity post-burn. This study highlights the importance of socioeconomic factors that may impact long-term outcomes and the use of aggregate markers to identify patients at risk for worse outcomes.

The prognostic relevance of full-thickness burns on ABSI

IntroductionThe Abbreviated Burn Severity Index (ABSI) by Tobiasen, which is commonly used to estimate the mortality risk of severely burned patients, calculates an additional point for the existence of full-thickness (third-degree) burns. [1] However, the score does not consider the extent of the body surface affected by third-degree burns. To understand whether there is a way to improve ABSI prediction power, this study aims to determine the influence of full-thickness burns on survival rates and how it affects the predictive precision of the ABSI. Material and methodsIn this study, the statistical evaluation of 2538 patients collected prospectively in the context of the German Burn Registry was carried out. A linear regression analysis was carried out to show the prognostic relevance of full-thickness burns. Age, sex, total body surface area burned (TBSA), and the presence of inhalation injury were also observed as further influencing factors. ResultsAmong the 2538 patients meeting our inclusion criteria, full-thickness burns were found in 1233 patients. In patients with a TBSA below 20 %, the extent of full-thickness burns is not relevant to the prognosis in terms of survival probability (p = 0.124). With more than 20 % TBSA, the extent of third-degree burns is of significant relevance (p = 0.000). In patients without full-thickness burns and calculated ABSI values ≥ 12 the survival rate of 46 % was noticeably better than the predicted survival rate of < 10 % according to the ABSI Score, whereas the predicted survival rate in patients with third-degree burns (< 10 %), closely matched the observed survival rate of 11 %. ConclusionFor patients with a TBSA < 20 %, the presence of full-thickness burns is not relevant for survival. In contrast to this observation, the percentage of full-thickness burns is of crucial prognostic importance for patients with a TBSA of > 20 %. By adjusting the ABSI and taking into account the exact percentage of third-degree burns, an improvement in the prognostic precision of the score could be achieved.