Chen, X.; Vogelmann, J.E.; Rollins, M.; Ohlen, D.; Key, C.H.; Yang, L.; Huang, C.; Shi, H.
It is challenging to detect burn severity and vegetation recovery because of the relatively long time period required to capture the ecosystem characteristics. Multitemporal remote sensing data can providemultitemporal observations before, during and after a wildfire, and can improve the change detection accuracy. The goal of this study is to examine the correlations between multitemporal spectral indices and field-observed burn severity, and to provide a practical method to estimate burn severity and vegetation recovery. The study site is the Jasper Fire area in the Black Hills National Forest, South Dakota, that burned during August and September 2000. Six multitemporal Landsat images acquired from 2000 (pre-fire), 2001 (post-fire), 2002, 2003, 2005 and 2007 were used to assess burn severity. The normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), normalized burn ratio (NBR), integrated forest index (IFI) and the differences of these indices between the pre-fire and post-fire years were computed and analysed with 66 field-based composite burn index (CBI) plots collected in 2002. Results showed that differences of NDVI and differences of EVI between the pre-fire year and the first two years post-fire were highly correlated with the CBI scores. The correlations were low beyond the second year post-fire. Differences of NBR had good correlation with CBI scores in all study years. Differences of IFI had low correlation with CBI in the first year post-fire and had good correlation in later years. A CBI map of the burnt area was produced using regression tree models and the multitemporal images. The dynamics of four spectral indices from 2000 to 2007 indicated that both NBR and IFI are valuable for monitoring long-term vegetation recovery. The high burn severity areas had a much slower recovery than the moderate and low burn areas. ?? 2011 Taylor & Francis.
Vegetation recovery and fuel accumulation rates following wildfire are useful measures of ecosystem resilience, yet few studies have quantified these variables over 10 years post-fire. Conventional wisdom is that recovery time to pre-fire condition will be slower as a function of burn severity, as i...
Oyler, J. W.; Smithwick, E.; Mack, M. C.
Fire is the dominant disturbance in the interior boreal region of Alaska and is predicted to increase with climate warming. This variation in the boreal fire regime could play a critical role in climate feedbacks by altering forest productivity and succession and, consequently, biogeochemical cycling, carbon sequestration, and surface energy fluxes. Due to limited fine-scale studies, however, it is not known how increased burn severity (i.e.-amount of organic material consumed) alters post-fire recovery of vegetation productivity, nor how the relationship between severity and post-fire recovery varies across heterogeneous landscapes. In examining fires from the 2004 Alaska fire season (n=72), the objective of this research was to determine how between and within fire variation in burn severity and related variables (pre-fire vegetation, elevation, insolation, etc.) mediates short-term post-fire recovery at the regional scale (i.e.-interior Alaska) and at the landscape scale (i.e.-a single fire complex).The Normalized Burn Ratio was used to measure burn severity and MODIS NDVI was used as a proxy for vegetation recovery. For the between fire analysis, remotely sensed data was overlaid on the fire perimeters in a GIS to create a multivariate dataset with variables aggregated by fire. The dependent variables for each fire were percent NDVI growing season change from 2003 to 2005 (i.e.-productivity drop) and from 2005 to 2007 (i.e.-productivity recovery), while the independent variables included mean dNBR, elevation, and insolation, and percentages of pre-fire land cover types. This dataset was explored in a geovisualization application (GeoViz Toolkit) to help interpret a more detailed adjusted R-square multivariate regression.The top 3 models (R-square ~ 0.60) for the productivity drop per fire showed that fires in higher elevations and containing higher percentages of pre-fire conifer forest were correlated with larger drops in NDVI. In contrast, the models for
Vieira, D. C. S.; Fernández, C.; Vega, J. A.; Keizer, J. J.
Soil burn severity has been widely used to describe the impacts of fire on soils and is increasingly being recognised as a decisive factor controlling post-fire erosion rates. However, there is no unique definition of the term and the relationship between soil burn severity and post-fire hydrological and erosion response has not yet been fully established. The objective of this work was to review the existing literature on the role of soil burn severity on post-fire runoff and erosion ratios. To this end, a meta-analysis was carried out of the runoff and inter-rill erosion data from field rainfall simulation experiments (RSE's) that compared burnt and unburnt conditions. In this study, 109 individual observations were analysed that covered a wide geographical range, various types of land cover (forest, shrubland, and grassland) and two types of fire types (wildfire and prescribed fire). The effect size of the post-fire runoff and erosion response was determined for four key factors: (i) soil burn severity; (ii) time-since-fire; (iii) rainfall intensity; and (iv) bare soil cover. Statistical meta-analysis showed that fire occurrence had a significant effect on the hydrological and erosive response. However, this effect was only significantly higher with increasing soil burn severity for inter-rill erosion, and not for runoff. This study furthermore highlighted the incoherencies between existing burn severity classifications, and proposed an unambiguous classification.
Kokaly, R.F.; Rockwell, B.W.; Haire, S.L.; King, T.V.V.
Forest fires leave behind a changed ecosystem with a patchwork of surface cover that includes ash, charred organic matter, soils and soil minerals, and dead, damaged, and living vegetation. The distributions of these materials affect post-fire processes of erosion, nutrient cycling, and vegetation regrowth. We analyzed high spatial resolution (2.4??m pixel size) Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) data collected over the Cerro Grande fire, to map post-fire surface cover into 10 classes, including ash, soil minerals, scorched conifer trees, and green vegetation. The Cerro Grande fire occurred near Los Alamos, New Mexico, in May 2000. The AVIRIS data were collected September 3, 2000. The surface cover map revealed complex patterns of ash, iron oxide minerals, and clay minerals in areas of complete combustion. Scorched conifer trees, which retained dry needles heated by the fire but not fully combusted by the flames, were found to cover much of the post-fire landscape. These scorched trees were found in narrow zones at the edges of completely burned areas. A surface cover map was also made using Landsat Enhanced Thematic Mapper plus (ETM+) data, collected September 5, 2000, and a maximum likelihood, supervised classification. When compared to AVIRIS, the Landsat classification grossly overestimated cover by dry conifer and ash classes and severely underestimated soil and green vegetation cover. In a comparison of AVIRIS surface cover to the Burned Area Emergency Rehabilitation (BAER) map of burn severity, the BAER high burn severity areas did not capture the variable patterns of post-fire surface cover by ash, soil, and scorched conifer trees seen in the AVIRIS map. The BAER map, derived from air photos, also did not capture the distribution of scorched trees that were observed in the AVIRIS map. Similarly, the moderate severity class of Landsat-derived burn severity maps generated from the differenced Normalized Burn Ratio (dNBR) calculation
Jin, Y.; Randerson, J. T.; Goetz, S. J.; Beck, P. S.; Loranty, M. M.; Goulden, M.
Severity of burning can influence multiple aspects of forest composition, carbon cycling, and climate forcing. We quantified how burn severity affected vegetation recovery and albedo change during early succession in Canadian boreal regions by combining satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Canadian Large Fire Data Base (LFDB). We used the difference Normalized Burn Ratio (dNBR) and changes in spring albedo derived from MODIS 500m albedo product as measures of burn severity. We found that the most severe burns had the greatest reduction in summer EVI in first year after fire, indicating greater loss of vegetation cover immediately following fire. By 5-7 years after fire, summer EVI for all severity classes had recovered to within 90-110% of pre-fire levels. Burn severity had a positive effect on the increase of post-fire spring albedo during the first 7 years after fire, and a shift from low to moderate or moderate to severe fires led to amplification of the post-fire albedo increase by approximately 30%. Fire-induced increases in both spring and summer albedo became progressively larger with stand age from years 1-7, with the trend in spring albedo likely driven by continued losses of needles and branches from trees killed by the fire (and concurrent losses of black carbon coatings on remaining debris), and the summer trend associated with increases in leaf area of short-stature herbs and shrubs. Our results suggest that increases in burn severity and carbon losses observed in some areas of boreal forests (e.g., Turetsky et al., 2011) may be at least partly offset by increases in negative forcing associated with changes in surface albedo.
Hudak, A. T.; Morgan, P.; Robichaud, P. R.; Lewis, S. A.; Evans, J. S.
Climate change may be contributing to regional warming and drying trends that are increasing the size and severity of wildfires. Regardless if climate is a factor, the escalating costs of fire suppression and post-fire rehabilitation on the many large fires of recent decades have driven a national effort to reduce hazardous fuels across large areas, particularly those in the wildland-urban interface (WUI). Nationally, concern is especially focused on the numerous large wildfires currently burning in the Northern Rocky Mountains with a need for rapid science-based assessment of burn severity, even as fires and fire suppression efforts continue. Our objective is to assess if and how well various fuels reduction treatments applied pre-fire mitigated burn severity measured in the field immediately post-fire. We will obtain data from the incident command teams, including fire weather, daily fire progression maps, and where strategic and tactical fire suppression measures were applied. Location and type of fuels treatment as well as data on local vegetation type, structure, and fuels will be obtained from local management agencies and national databases. We will pair our sampled field plots in treated and burned areas with those not treated and burned in similar stand and topographic conditions across three or more large forest fires. Our analysis is both quantitative and qualitative, and linked with efforts to assess fuel treatment effects on fire behavior and ease of fire suppression. We report specifically on whether various fuels treatments are mitigating fire effects on soil (e.g., char, percent exposed, infiltration rate, water repellency) and vegetation (e.g., scorch, tree mortality, understory abundance, recovery). We discuss which fuels treatments work and which do not work, and the extent to which fire weather and other factors beyond the control of fire managers may determine whether or not fuels treatments are effectively mitigating severe fire effects.
Post-fire Vegetation Regeneration Dynamics to Topography and Burn Severity in two contrasting ecosystems: the Case of the Montane Cordillera Ecozones of Western Canada & that of a Typical Mediterranean site in Greece
Ireland, Gareth; Petropoulos, George P.; Kalivas, Dionissios; Griffirths, Hywel M.; Louka, Panagiota
Altering land cover dynamics is currently regarded as the single most important variable of global change affecting ecological systems. Wildfires are an integral part of many terrestrial ecosystems and are considered to dramatically affect land cover dynamics at a variety of spatial and temporal scales. In this context, knowledge of the spatio-temporal distribution of post-fire vegetation recovery dynamics is of key importance. In this study, we explore the relationships between vegetation recovery dynamics to topography and burn severity for two different ecosystems using a chronosequence of Landsat TM data images analysis. One of our experimental sites is the Okanagan Mountain Park, located in the Montane Cordillera Ecozones of western Canada at which a fire occurred in 2003. The other is Mt. Parnitha, located in Greece, representing a typical Mediterranean setting. The spatio-temporal patterns of regrowth for 8 years following the fire events were quantified based on the analysis of 2 widely used indices, the Normalized Difference Vegetation Index (NDVI) and the Regeneration Index (RI). Burn severity was derived from the differenced Normalized Burn Ratio (dNBR) index computed from the Landsat TM images. Topographical information for the studied area was obtained from the ASTER global operational product. Relationships of vegetation regrowth to both topography and burn severity was quantified using a series of additional statistical metrics. In overall, results indicated noticeable differences in the recovery rates of both ecosystems to the pre-fire patterns. Re-growth rates appeared to be somewhat higher in north-facing slopes in comparison to south facing ones for both experimental sites, in common with other similar studies in different ecosystems. Lastly, areas of lower burn severity exhibited a higher recovery rate compared to areas of high severity burns. Results are presented in detail and an explanation of the main observation trends is also attempted to
Wildland fires are common in rangelands worldwide. The potential for high severity fires to affect long-term changes in rangelands is considerable, and for this reason assessing fire severity shortly after the fire is critical. Such assessments are typically carried out following Burned Area Emergen...
Bowman-Prideaux, C.; Newingham, B. A.
Historically, aridlands have had infrequent fire due to patchy plant distributions, which limit fire spread. However, aridland fire regimes have changed because invasive annual grasses have created continuous fuel beds, which have led to increasingly frequent fires and a greater area burned each decade since the 1970s. Climate change is predicted to further increase the number and size of fires. Post-fire rehabilitation is enacted in order to reestablish plant communities and has the potential to further alter fire regimes. Rehabilitation treatments include tilling seeds using a tractor and drill (drill seeding), dropping seed aerially with helicopters (aerial seeding), or both. Few studies examine the impact of post-fire rehabilitation on the likelihood of future fires in these aridland ecosystems. We examined the effects of post-fire rehabilitation treatments on the number of years before the next fire. Using GIS layers detailing fire history and post-fire rehabilitation treatments in the southern Idaho Great Basin, we extracted information from randomly selected sites and analyzed them with generalized linear models. Preliminary analysis on 43 sites suggests the number of years before the next fire tended to be less in seeded than unseeded sites (P=0.055). Further investigation revealed that the number of years until the next fire differed among seed application methods. Sites that were drill seeded burned approximately 12 years later while sites with combined aerial and drill seeding burned again after 6.5 years (P=0.05). The total number of burns at a site was inversely related to the time before the next fire (P=0.001). After the first fire, sites averaged 17.4 years before the next fire occurred; this decreased with each subsequent fire to 7.1 years after the fifth fire. The number of times a site burned and the rehabilitation treatment interacted to affect the number of years between fires. In sites that burned once, there was on average 27.75 years before
Madsen, Matthew; Zvirzdin, Daniel; Fernelius, Kaitlynn; McMillan, Mica; Kostka, Stanley
Erosion and weed dominance often limit the recovery of piñon-juniper woodlands of western North America after high intensity wildfires. Soil water repellency (SWR) is one factor that may promote overland flow and impede seedling establishment. In spite of these effects, the influence of post-fire SWR on site recovery is poorly understood. Our presentation summarizes data collected within studies on burned piñon-juniper woodlands that provide new insight on: 1) the spatial distribution and severity of SWR, 2) influence of SWR on soil hydrology, nitrogen cycling, and site revegetation, and 3) the suitability of soil surfactants as a post-fire restoration tool. We demonstrate how patterns of SWR are highly correlated to pre-fire woodland canopy structure. At sites where SWR is present, infiltration, soil water content, and plant establishment is significantly less than at non-hydrophobic sites. We show how newly developed soil surfactants can significantly improve ecohydrologic properties required for plant growth by overcoming SWR; thus, increasing the amount and duration of available water for seed germination and plant growth. However, the application of soil surfactants in wildfire-affected ecosystems has been limited due to logistical and economic constraints associated with the standard practice of using large quantities of irrigation water as the surfactant carrier. We have developed a potential solution to this problem by using seed coating technology to use the seed as the carrier for the delivery of soil surfactant. Through this approach, precipitation leaches the surfactant from the seed into the soil where it absorbs onto the soil particles and ameliorates water repellency within the seeds microsite. We present findings from laboratory and field evaluations of surfactant seed coatings, which provide evidence that it may be plausible for the technology to improve post-fire seeding efforts by restoring soil hydrologic function and increasing seedling
Keesstra, S. D.; Wittenberg, L.; Voogt, A.; Argaman, E.; Malkinson, D.
Mediterranean forests are frequently subject to wildfires, inducing risks of runoff and loss of nutrient-rich topsoil. Post-fire causes for soil erosion are hard to separate. These mechanisms are spatially variable due to differences in vegetation density, litter composition, soil texture and structure, and fire intensity. However, the characteristics of soil and surface in the immediate post-fire period are of critical importance to the hydrological response and erosion susceptibility of the burned hillslope and catchment. The mentioned variation is still present in laboratory experiments, however a lot of it can be reduced by using homogeneous litter, uniform soil amounts and texture, controlled temperature and rain regimes and by replicating treatments. Moreover, fire and rain events can be simulated, enabling an imitation of a post-fire period. In this study we looked at post-fire observations for laboratory fire and rainfall (nozzle-type) simulation experiments to evaluate short-term effects of fire on soil hydrological and erodibility parameters by investigating (i) soil water repellency (WR) levels and distribution, (ii) surface cover features, and (iii) sat. hydraulic conductivity (Ksat), electrical conductivity and values of infiltration, runoff and erosion responses to simulated rain on control (bare and needle covered) and burned (with and without ash cover) samples. In the laboratory experiments we used a novel combination of techniques: (i) prepared trays of soil were manually burned; (ii) WR was measured before, in-between and after rainfall simulations; (iii) assessing of the degree and spatial variation for preferential surface flow; (iv) two rainfall simulations with drying period to simulate a part of a rainy season with cycles of wetting and drying (with its effects on soil hydrology, (re-)establishment hydrophobicity). The fire-induced surface WR in the lab, tested by grid-wise Water Drop Penetration tests, was moderate but decreased for all
Poore, R.; Wessman, C. A.; Buma, B.
horizon and the top 10cm mineral horizon. The soils were sieved to 2mm and their BC content measured using the Kurth-MacKenzie-DeLuca method of digesting labile carbon using nitric acid and hydrogen peroxide at 95C for 20hrs. We integrated both remotely sensed data and field observations. We used the Relative Difference Normalized Burn Ratio (RdNBR) calculated by Monitoring Trends in Burn Severity (MTBS). This index used Landsat images from July in the years before and after the fire and is based on differences in bands 4 and 7, with the aim of assessing coarse scale changes in soil and vegetation post fire. For each plot we also collected data on tree mortality and organic soil depth. These metrics were chosen from the Composite Burn Index as those that were most reliable even 10 years after the fire. We observed no significant differences in BC totals between high severity fire and unburned plots, although BC increased slightly on burned plots. Early results for low severity sites (analysis still in progress) suggest that BC increased in plots experiencing lower severity fires compared to unburned and high severity plots. Comparing carbon and BC totals on unburned and severely burned plots, and assuming no loss of BC from mineral soil during the fire, we observed a 1.2% conversion of burned biomass to BC, which corresponds with literature estimates of 1-4%.
Lukenbach, M. C.; Devito, K. J.; Kettridge, N.; Petrone, R. M.; Waddington, J. M.
Wildfire is the largest disturbance affecting boreal peatlands, however, little is known about the controls on post-fire peatland vegetation recovery. While small-scale variation in burn severity can reduce post-fire moss water availability, high water table (WT) positions following wildfire are also critical to enable the re-establishment of keystone peatland mosses (i.e. Sphagnum). Thus, post-fire moss water availability is also likely a function of landscape-scale controls on peatland WT dynamics, specifically, connectivity to groundwater flow systems (i.e. hydrogeological setting). For this reason, we assessed the interacting controls of hydrogeological setting and burn severity on post-fire moss water availability in three burned, Sphagnum-dominated peatlands in Alberta's Boreal Plains. At all sites, variation in burn severity resulted in a dichotomy between post-fire surface covers that: (1) exhibited low water availability, regardless of WT position, and had minimal (<5%) moss re-establishment (i.e. lightly burned feather mosses and severely burned Sphagnum fuscum) or (2) exhibited high water availability, depending on WT position, and had substantial (>50%) moss re-establishment (i.e. lightly burned S. fuscum and where depth of burn was >0.05 m). Notably, hydrogeological setting influenced the spatial coverage of these post-fire surface covers by influencing pre-fire WTs and stand characteristics (e.g., shading). Because feather moss cover is controlled by tree shading, lightly burned feather mosses were ubiquitous (>25%) in drier peatlands (deeper pre-fire WTs) that were densely treed and had little connection to large groundwater flow systems. Moreover, hydrogeological setting also controlled post-fire WT positions, thereby affecting moss re-establishment in post-fire surface covers that were dependent on WT position (e.g., lightly burned S. fuscum). Accordingly, higher recolonization rates were observed in a peatland located in a groundwater flow through
Tonbul, H.; Kavzoglu, T.; Kaya, S.
Satellite based remote sensing technologies and Geographical Information Systems (GIS) present operable and cost-effective solutions for mapping fires and observing post-fire regeneration. Mersin-Gülnar wildfire, which occurred in August 2008 in Turkey, selected as study site. The fire was devastating and continued 55 days. According to Turkish General Directorate of Forestry reports, it caused two deaths and left hundreds of people homeless. The aim of this study is to determine the fire severity and monitor vegetation recovery with using multitemporal spectral indices together with topographical factors. Pre-fire and post-fire Landsat ETM+ images were obtained to assess the related fire severity with using the widely-used differenced Normalized Burn Ratio (dNBR) algorithm. Also, the Normalized Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) were used to determine vegetation regeneration dynamics for a period of six consecutive years. In addition, aspect image derived from Aster Global Digital Elevation Model (GDEM) were used to determine vegetation regeneration regime of the study area. Results showed that 5388 ha of area burned with moderate to high severity damage. As expected, NDVI and SAVI values distinctly declined post-fire and then began to increase in the coming years. Mean NDVI value of burned area changed from 0.48 to 0.17 due to wildfire, whilst mean SAVI value changed from 0.61 to 0.26. Re-growth rates calculated for NDVI and SAVI 57% and 63% respectively, six years after the fire. Moreover, NDVI and SAVI were estimated six consecutive year period by taking into consideration east, south, north and west facing slopes. Analysis showed that north-facing and east-facing slopes have higher regeneration rates in compared to other aspects. This study serves as a window to an understanding of the process of fire severity and vegetation regeneration that is vital in wildfire management systems.
Lukenbach, Max; Devito, Kevin; Kettridge, Nicholas; Petrone, Richard; Waddington, James
Wildfire is the largest disturbance affecting peatlands, however, little is known about the spatiotemporal variability of post-fire recovery in these ecosystems. High water table (WT) positions after wildfire are critical to limit atmospheric carbon losses and enable the re-establishment of keystone peatland mosses (i.e. Sphagnum). While small-scale variation in burn severity can reduce capillary flow from the WT and lead to a dry surface after fire, steep WT declines can also limit post-fire moss water availability. As such, post-fire moss water availability is also a function of large-scale controls on peatland WT dynamics, specifically, connectivity to groundwater flow systems (i.e. hydrogeological setting). For this reason, we assessed the interacting controls of hydrogeological setting and burn severity on post-fire moss water availability by measuring peatland WTs, soil tension (Ψ) and surface volumetric moisture content (θ) in three burned, Sphagnum-dominated peatlands located in different hydrogeological settings for three years following wildfire. The effect of burn severity on post-fire moss water availability did not vary with hydrogeological setting, however, the spatial coverage of high and low burn severity did vary between peatlands located in different hydrogeological settings due to its influence on pre-fire fuel loads and species cover. Locations covered by S. fuscum prior to fire exhibited decreasing post-fire water availability with increasing burn severity. In contrast, the lowest water availability (Ψ > 400 cm, θ < 0.02) was observed in feather mosses that underwent low burn severity (residual branches identifiable). Where depth of burn was > 0.05 m (high burn severity) and pre-fire species were not identifiable, water availability was highest (Ψ < 90 cm). Where burn severity did not limit water availability through a reduction of capillary flow, depth to WT (and therefore hydrogeological setting) played a large role in affecting post-fire
Veraverbeke, Sander; Lhermitte, Stefaan; Verstraeten, Willem; Goossens, Rudi
In this study a multi-temporal differenced Normalized Burn Ratio (dNBRMT) is presented to assess burn severity of the 2007 Peloponnese (Greece) wildfires. 8-day composites were created using the daily near infrared (NIR) and mid infrared (MIR) reflectance products of the Moderate Resolution Imaging Spectroradiometer (MODIS). Prior to the calculation of the dNBRMT a pixel-based control plot selection procedure was initiated for each burned pixel based on time series similarity of the pre-fire year 2006 to estimate the spatio-temporal NBR dynamics in the case that no fire event would have occurred. The dNBRMT is defined as the one-year post-fire integrated difference between the NBR values of the control and focal pixels. Results reveal the temporal dependency of the absolute values of bi-temporal dNBR maps as the mean temporal standard deviation of the one-year post-fire bi-temporal dNBR time series equaled 0.14 (standard deviation of 0.04). The dNBRMT's integration of temporal variability into one value potentially enhances the comparability of fires across space and time. In addition, the dNBRMT is robust to random noise thanks to the averaging effect. The dNBRMT, based on coarse resolution imagery with high temporal frequency, has the potential to become either a valuable complement to fine resolution Landsat dNBR mapping or an imperative option for assessing burn severity at a continental to global scale.
Skinner, Kenneth D.
A preliminary hazard assessment was developed for debris-flow hazards in the 465 square-kilometer (115,000 acres) area burned by the 2013 Beaver Creek fire near Hailey in central Idaho. The burn area covers all or part of six watersheds and selected basins draining to the Big Wood River and is at risk of substantial post-fire erosion, such as that caused by debris flows. Empirical models derived from statistical evaluation of data collected from recently burned basins throughout the Intermountain Region in Western United States were used to estimate the probability of debris-flow occurrence, potential volume of debris flows, and the combined debris-flow hazard ranking along the drainage network within the burn area and to estimate the same for analyzed drainage basins within the burn area. Input data for the empirical models included topographic parameters, soil characteristics, burn severity, and rainfall totals and intensities for a (1) 2-year-recurrence, 1-hour-duration rainfall, referred to as a 2-year storm (13 mm); (2) 10-year-recurrence, 1-hour-duration rainfall, referred to as a 10-year storm (19 mm); and (3) 25-year-recurrence, 1-hour-duration rainfall, referred to as a 25-year storm (22 mm). Estimated debris-flow probabilities for drainage basins upstream of 130 selected basin outlets ranged from less than 1 to 78 percent with the probabilities increasing with each increase in storm magnitude. Probabilities were high in three of the six watersheds. For the 25-year storm, probabilities were greater than 60 percent for 11 basin outlets and ranged from 50 to 60 percent for an additional 12 basin outlets. Probability estimates for stream segments within the drainage network can vary within a basin. For the 25-year storm, probabilities for stream segments within 33 basins were higher than the basin outlet, emphasizing the importance of evaluating the drainage network as well as basin outlets. Estimated debris-flow volumes for the three modeled storms range
Fernández, Cristina; Vega, José A.; Fonturbel, Teresa
Prescribed burning is commonly used to reduce the risk of severe wildfire. However, further information about the associated environmental effects is required to help forest managers select the most appropriate treatment. To address this question, we evaluated if fire severity during spring prescribed burning significantly affects the resprouting ability of two common shrub species in shrubland under a Mediterranean climate in NW Spain. Fire behaviour and temperatures were recorded in tagged individuals of Erica australis and Pterospartum tridentatum during prescribed burning. The number and length of resprouted shoots were measured three times (6, 12 and 18 months) after the prescribed burning. The influence of a series of fire severity indicators on some plant resprouting vigour parameters was tested by canonical correlation analysis. Six months and one year after prescribed burning, soil burn severity (measured by the absolute reduction in depth of the organic soil layer, maximum temperatures in the organic soil layer and the mineral soil surface during burning and the post-fire depth of the organic soil layer) reduced the resprouting vigour of E. australis and P. tridentatum. In contrast, direct measurements of fire effects on plants (minimum branch diameter, duration of temperatures above 300 °C in the shrub crown and fireline intensity) did not affect the post-fire plant vigour. Soil burn severity during spring prescribed burning significantly affected the short-term resprouting vigour in a mixed heathland in Galicia. The lack of effects eighteen months after prescribed burning indicates the high resilience of these species and illustrates the need to conciliate fire prevention and conservation goals.
Quintano, C.; Fernández-Manso, A.; Calvo, L.; Marcos, E.; Valbuena, L.
Forest fires are one of the most important causes of environmental alteration in Mediterranean countries. Discrimination of different degrees of burn severity is critical for improving management of fire-affected areas. This paper aims to evaluate the usefulness of land surface temperature (LST) as potential indicator of burn severity. We used a large convention-dominated wildfire, which occurred on 19-21 September, 2012 in Northwestern Spain. From this area, a 1-year series of six LST images were generated from Landsat 7 Enhanced Thematic Mapper (ETM+) data using a single channel algorithm. Further, the Composite Burn Index (CBI) was measured in 111 field plots to identify the burn severity level (low, moderate, and high). Evaluation of the potential relationship between post-fire LST and ground measured CBI was performed by both correlation analysis and regression models. Correlation coefficients were higher in the immediate post-fire LST images, but decreased during the fall of 2012 and increased again with a second maximum value in summer, 2013. A linear regression model between post-fire LST and CBI allowed us to represent spatially predicted CBI (R-squaredadj > 85%). After performing an analysis of variance (ANOVA) between post-fire LST and CBI, a Fisher's least significant difference test determined that two burn severity levels (low-moderate and high) could be statistically distinguished. The identification of such burn severity levels is sufficient and useful to forest managers. We conclude that summer post-fire LST from moderate resolution satellite data may be considered as a valuable indicator of burn severity for large fires in Mediterranean forest ecosytems.
Dobre, Mariana; Elliot, William J.; Brooks, Erin S.; Smith, Tim
Wildfires can have major adverse effects on municipal water sources. Local governments need methods to evaluate fire risk and to develop mitigation procedures. The Sooke Lake Reservoir is the primary source of water for the city of Victoria, BC and the concern is that sediment delivered from upland burned areas could have a detrimental impact on the reservoir and the water supply. We conducted a sediment delivery modeling pilot study on a portion of the Sooke Lake Reservoir (specifically, the Trestle Creek Management Unit (TCMU)) to evaluate the potential impacts of wildfire on sediment delivery from hillslopes and sub-catchments. We used a process-based hydrologic and soil erosion model called Water Erosion Prediction Project geospatial interface, GeoWEPP, to predict the sediment delivery from specific return period design storms for two burn severity scenarios: real (low-intensity burn severity) and worst (high-intensity burn severity) case scenarios. The GeoWEPP model allows users to simulate streamflow and erosion from hillslope polygons within a watershed. The model requires information on the topographic, soil and vegetative characteristics for each hillslope and a weather file. WEPP default values and several assumptions were necessary to apply the model where data were missing. Based on a 10-m DEM we delineated 16 watersheds within the TCMU area. A long term 100-year daily climate file was generated for this analysis using the CLIGEN model based on the historical observations recorded at Concrete, WA in United States, and adjusted for observed monthly precipitation observed in the Sooke Basin. We ran 100-year simulations and calculated yearly and event-based return periods (for 2, 5, 10, 20, 25, and 50 years) for each of the 16 watersheds. Overall, WEPP simulations indicate that the storms that are most likely to produce the greatest runoff and sediment load in these coastal, maritime climates with relatively low rainfall intensities are likely to occur in
Veraverbeke, S.; Hulley, G. C.; Harris, S. L.; Hook, S.
Wildfires play an important role in many ecosystems by modifying the earth's carbon balance and post-fire landscape composition. Remote sensing can fulfill an important role for monitoring post-fire landscapes as it allows timely and cost-effective assessments. Most of the current applications rely on the visible and near infrared (VNIR) to short-wave infrared (SWIR) spectral region (0.4 to 2.5 μm). In this spectral range many burn indices have been applied to assess post-fire effects, e.g. the Normalized Burn Ratio (NBR) or Normalized Difference Vegetation Index (NDVI). Few studies have assessed the potential of the mid infrared (MIR) and thermal infrared (TIR) data. In this paper MODIS/ASTER (MASTER) airborne simulator data acquired over several burn scars is used to evaluate spectral indices in the 0.4-13 μm range. A first application focuses on the spectral separability of several burn indices for burned area mapping applied over three 2007 southern California scars. In a second application, a novel SWIR-MIR index (SMI) is proposed for assessing fire severity of the large 2011 Wallow wildfire in Arizona. Compared to the traditionally used differenced NBR (dNBR), the SMI has two major advantages: (i) the index is not impeded by smoke and (ii) the approach is based on a single date image. Findings can have important implications for the next generation spaceborne sensor, e.g. the Hyperspectral Infrared Imager (HyspIRI).
Sparks, A. M.; Smith, A. M.; Kolden, C.; Apostol, K. G.; Boschetti, L.
Fire is a common disturbance in forested ecosystems in the western U.S. and can be responsible for long-term impacts on vegetation and soil. An improved understanding of how ecosystems recover after fire is necessary so that land managers can plan for and mitigate the effects of these disturbances. Although several studies have attempted to link fire intensity with severity, direct links between spectral indices of severity and key physiological changes in vegetation are not well understood. We conducted an assessment of how two western conifer species respond to four fire radiative energy treatments, with spectra acquired pre- and up to a month post-burn. After transforming the spectral data into Landsat 8 equivalent reflectance, burn severity indices commonly used in the remote sensing community were compared to concurrent physiological measurements including gas exchange and photosynthetic rate. Preliminary results indicate significant relationships between several fire severity indices and physiological responses measured in the conifer seedlings.
Baker, Patrick; Oborne, Lisa
Large, high-intensity fires have direct and long-lasting effects on forest ecosystems and present a serious threat to human life and property. However, even within the most catastrophic fires there is important variability in local-scale intensity that has important ramifications for forest mortality and regeneration. Quantifying this variability is difficult due to the rarity of catastrophic fire events, the extreme conditions at the time of the fires, and their large spatial extent. Instead fire severity is typically measured or estimated from observed patterns of vegetation mortality; however, differences in species- and size-specific responses to fires often makes fire severity a poor proxy for fire intensity. We developed a statistical method using simple, plot-based measurements of individual tree mortality to simultaneously estimate plot-level fire intensity and species-specific mortality patterns as a function of tree size. We applied our approach to an area of forest burned in the catastrophic Black Saturday fires that occurred near Melbourne, Australia, in February 2009. Despite being the most devastating fire in the past 70 years and our plots being located in the area that experienced some of the most intense fires in the 350,000 ha fire complex, we found that the estimated fire intensity was highly variable at multiple spatial scales. All eight tree species in our study differed in their susceptibility to fire-induced mortality, particularly among the largest size classes. We also found that seedling height and species richness of the post-fire seedling communities were both positively correlated with fire intensity. Spatial variability in disturbance intensity has important, but poorly understood, consequences for the short- and long-term dynamics of forests in the wake of catastrophic wildfires. Our study provides a tool to estimate fire intensity after a fire has passed, allowing new opportunities for linking spatial variability in fire intensity to
Weber, K.; Schnase, J. L.; Carroll, M.; Brown, M. E.; Gill, R.; Haskett, G.; Gardner, T.
In partnership with the Department of Interior's Bureau of Land Management (BLM) and the Idaho Department of Lands (IDL), we are building and evaluating the RECOVER decision support system. RECOVER - which stands for Rehabilitation Capability Convergence for Ecosystem Recovery - is an automatically deployable, context-aware decision support system for savanna wildfires that brings together in a single application the information necessary for post-fire rehabilitation decision-making and long-term ecosystem monitoring. RECOVER uses state-of-the-art cloud-based data management technologies to improve performance, reduce cost, and provide site-specific flexibility for each fire. The RECOVER Server uses Integrated Rule-Oriented Data System (iRODS) data grid technology deployed in the Amazon Elastic Compute Cloud (EC2). The RECOVER Client is an Adobe Flex web map application that is able to provide a suite of convenient GIS analytical capabilities. In a typical use scenario, the RECOVER Server is provided a wildfire name and geospatial extent. The Server then automatically gathers Earth observational data and other relevant products from various geographically distributed data sources. The Server creates a database in the cloud where all relevant information about the wildfire is stored. This information is made available to the RECOVER Client and ultimately to fire managers through their choice of web browser. The Server refreshes the data throughout the burn and subsequent recovery period (3-5 years) with each refresh requiring two minutes to complete. Since remediation plans must be completed within 14 days of a fire's containment, RECOVER has the potential to significantly improve the decision-making process. RECOVER adds an important new dimension to post-fire decision-making by focusing on ecosystem rehabilitation in semiarid savannas. A novel aspect of RECOVER's approach involves the use of soil moisture estimates, which are an important but difficult
Post-fire Vegetation regeneration effects on runoff and sediment yield: slope, aspect and fire severityPost-fire Vegetation regeneration effects on runoff and sediment yield: slope, aspect and fire severity
Barzilai, R.; Wittenberg, L.; Malkinson, D.
1 Post-fire Vegetation regeneration effects on runoff and sediment yield: slope, aspect and fire severity During the last several decades fire occurrence at the Carmel Mountain ridge has been increasing, showing similar trends to the ones observed in the Mediterranean basin. Wildfires damage and destroy the vegetation and therefore alter the components of the eco-geomorphic system, which leads to an increase in runoff and sediment yields. In April, 2005 a wildfire consuming 154 ha of planted and natural vegetation occurred at the north-western part of the Carmel ridge. Following the event, a 2x2x2 factorial design of monitoring plots was established to examine the relationship between vegetation recovery, runoff and sediment yield. Namely, slope aspect, slope steepness and fire severity were specifically examined in relation to the above mentioned response variables. The research methods included (a) the establishment of 14 plots of ~ 10.5m2 each, designed for runoff and sediment collection and for monitoring vegetation cover change. (b) Monthly aerial photography of the research plots using a pole-mounted camera. The images were digitally classified to identify rock cover, vegetation cover, and bare soil patches. The time dependent vegetation regeneration was used for assessing landscape recovery. (c) Collection of runoff and sediment yield after each rain event. Multiple regression analysis was conducted in order to determine the relative importance of land cover classes and different precipitation parameters on runoff and sediment yield. Vegetation recovery rates during the first wet season were relatively low; by the end of the first spring season vegetation cover reached 30%-35%. During the first summer, a year after the fire, there was a slight decrease in vegetation cover, due to the die off of the annual herbaceous vegetation. In the second winter vegetation cover continued to increase, and by the end of the research period (summer 2007) average vegetation
The Structure of Flameballs at Low Lewis Numbers (SOFBALL) experiments aboard the space shuttle in 1997 a series of sturningly successful burns. This sequence was taken during STS-94, July 12, 1997, MET:10/08:18 (approximate). It was thought these extremely dim flameballs (1/20 the power of a kitchen match) could last up to 200 seconds -- in fact, they can last for at least 500 seconds. This has ramifications in fuel-spray design in combustion engines, as well as fire safety in space. The SOFBALL principal investigator was Paul Ronney, University of Southern California, Los Angeles. The experiment was part of the space research investigations conducted during the Microgravity Science Laboratory-1R mission (STS-94, July 1-17 1997). Advanced combustion experiments will be a part of investigations planned for the International Space Station. (925KB, 9-second MPEG spanning 10 minutes, screen 320 x 240 pixels; downlinked video, higher quality not available) A still JPG composite of this movie is available at http://mix.msfc.nasa.gov/ABSTRACTS/MSFC-0300186.html.
Chen, Gang; Metz, Margaret R.; Rizzo, David M.; Meentemeyer, Ross K.
Global environmental change has increased forest vulnerability to the occurrence of interacting disturbances, including wildfires and invasive diseases. Mapping post-fire burn severity in a disease-affected forest often faces challenges because burned and infested trees may exhibit a high similarity in spectral reflectance. In this study, we combined (pre- and post-fire) Landsat imagery and (post-fire) high-spectral resolution airborne MASTER data [MODIS (moderate resolution imaging spectroradiometer)/ASTER (advanced spaceborne thermal emission and reflection radiometer)] to map burn severity in a California coastal forest environment, where a non-native forest disease sudden oak death (SOD) was causing substantial tree mortality. Results showed that the use of Landsat plus MASTER bundle performed better than using the individual sensors in most of the evaluated forest strata from ground to canopy layers (i.e., substrate, shrubs, intermediate-sized trees, dominant trees and average), with the best model performance achieved at the dominant tree layer. The mid to thermal infrared spectral bands (3.0-12.5 μm) from MASTER were found to augment Landsat's visible to shortwave infrared bands in burn severity assessment. We also found that infested and uninfested forests similarly experienced moderate to high degrees of burns where CBI (composite burn index) values were higher than 1. However, differences occurred in the regions with low burn severity (CBI values lower than 1), where uninfested stands revealed a much lower burn effect than that in infested stands, possibly due to their higher resilience to small fire disturbances as a result of higher leaf water content.
Kinoshita, Alicia; Nourbakhshbeidokhti, Samira; Chin, Anne
Wildfire can have significant impacts on watershed hydrology and geomorphology by changing soil properties and removing vegetation, often increasing runoff and soil erosion and deposition, debris flows, and flooding. Watershed systems may take several years or longer to recover. During this time, post-fire channel changes have the potential to alter hydraulics that influence characteristics such as time of concentration and increase time to peak flow, flow capacity, and velocity. Using the case of the 2012 Waldo Canyon Fire in Colorado (USA), this research will leverage field-based surveys and terrestrial Light Detection and Ranging (LiDAR) data to parameterize KINEROS2 (KINematic runoff and EROSion), an event oriented, physically-based watershed runoff and erosion model. We will use the Automated Geospatial Watershed Assessment (AGWA) tool, which is a GIS-based hydrologic modeling tool that uses commonly available GIS data layers to parameterize, execute, and spatially visualize runoff and sediment yield for watersheds impacted by the Waldo Canyon Fire. Specifically, two models are developed, an unburned (Bear Creek) and burned (Williams) watershed. The models will simulate burn severity and treatment conditions. Field data will be used to validate the burned watersheds for pre- and post-fire changes in infiltration, runoff, peak flow, sediment yield, and sediment discharge. Spatial modeling will provide insight into post-fire patterns for varying treatment, burn severity, and climate scenarios. Results will also provide post-fire managers with improved hydro-geomorphic modeling and prediction tools for water resources management and mitigation efforts.
Wu, Zhuoting; Middleton, Barry R.; Hetzler, Robert; Vogel, John M.; Dye, Dennis G.
We used remotely sensed data from the Landsat-8 and WorldView-2 satellites to estimate vegetation burn severity of the Creek Fire on the San Carlos Apache Reservation, where wildfire occurrences affect the Tribe's crucial livestock and logging industries. Accurate pre- and post-fire canopy maps at high (0.5-meter) resolution were created from World- View-2 data to generate canopy loss maps, and multiple indices from pre- and post-fire Landsat-8 images were used to evaluate vegetation burn severity. Normalized difference vegetation index based vegetation burn severity map had the highest correlation coefficients with canopy loss map from WorldView-2. Two distinct approaches - canopy loss mapping from WorldView-2 and spectral index differencing from Landsat-8 - agreed well with the field-based burn severity estimates and are both effective for vegetation burn severity mapping. Canopy loss maps created with WorldView-2 imagery add to a short list of accurate vegetation burn severity mapping techniques that can help guide effective management of forest resources on the San Carlos Apache Reservation, and the broader fire-prone regions of the Southwest.
Kalogeropoulos, Christos; Amatulli, Giuseppe; Kempeneers, Pieter; Sedano, Fernando; San Miguel-Ayanz, Jesus; Camia, Andrea
The Mediterranean region is highly susceptible to wildfires. On average, about 60,000 fires take place in this region every year, burning on average half a million hectares of forests and natural vegetation. Wildfires cause environmental degradation and affect the lives of thousands of people in the region. In order to minimize the consequences of these catastrophic events, fire managers and national authorities need to have in their disposal accurate and updated spatial information concerning the size of the burned area as well as the burn severity patterns. Mapping burned areas and burn severity patterns is necessary to effectively support the decision-making process in what concerns strategic (long-term) planning with the definition of post-fire actions at European and national scales. Although a comprehensive archive of burnt areas exists at the European Forest Fire Information System, the analysis of the severity of the areas affected by forest fires in the region is not yet available. Fire severity is influenced by many variables, including fuel type, topography and meteorological conditions before and during the fire. The analysis of fire severity is essential to determine the socio-economic impact of forest fires, to assess fire impacts, and to determine the need of post-fire rehabilitation measures. Moreover, fire severity is linked to forest fire emissions and determines the rate of recovery of the vegetation after the fire. Satellite imagery can give important insights about the conditions of the live fuel moisture content and can be used to assess changes on vegetation structure and vitality after forest fires. Fire events occurred in Greece, Portugal and Spain during the fire season of 2009 were recorded and analyzed in a GIS environment. The Normalized Difference Vegetation Index (NDVI), the Enhanced Vegetation Index (EVI) and the Normalized Burn Ratio (NBR) were calculated from 8-days composites MODIS/TERRA imagery from March to October 2009. In
Dragozi, E.; Gitas, Ioannis Z.; Stavrakoudis, Dimitris G.; Minakou, C.
Forest fires greatly influence the stability and functions of the forest ecosystems. The ever increasing need for accurate and detailed information regarding post-fire effects (burn severity) has led to several studies on the matter. In this study the combined use of Very High Resolution (VHR) satellite data (GeoEye), Objectbased image analysis (OBIA) and Composite Burn Index (CBI) measurements in estimating burn severity, at two different time points (2011 and 2012) is assessed. The accuracy of the produced maps was assessed and changes in burn severity between the two dates were detected using the post classification comparison approach. It was found that the produced burn severity map for 2011 was approximately 10% more accurate than that of 2012. This was mainly attributed to the increased heterogeneity of the study area in the second year, which led to an increased number of mixed class objects and consequently made it more difficult to spectrally discriminate between the severity classes. Following the post-classification analysis, the severity class changes were mainly attributed to the trees' ability to survive severe fire damage and sprout new leaves. Moreover, the results of the study suggest that when classifying CBI-based burn severity using VHR imagery it would be preferable to use images captured soon after the fire.
Birch, Donovan S.; Morgan, Penelope; Kolden, Crystal A.; Hudak, Andrew T.; Smith, Alistair M. S.
The ecological effects of forest fires burning with high severity are long-lived and have the greatest impact on vegetation successional trajectories, as compared to low-to-moderate severity fires. The primary drivers of high severity fire are unclear, but it has been hypothesized that wind-driven, large fire-growth days play a significant role, particularly on large fires in forested ecosystems. Here, we examined the relative proportion of classified burn severity for individual daily areas burned that occurred during 42 large forest fires in central Idaho and western Montana from 2005 to 2007 and 2011. Using infrared perimeter data for wildfires with five or more consecutive days of mapped perimeters, we delineated 2697 individual daily areas burned from which we calculated the proportions of each of three burn severity classes (high, moderate, and low) using the differenced normalized burn ratio as mapped for large fires by the Monitoring Trends in Burn Severity project. We found that the proportion of high burn severity was weakly correlated (Kendall τ = 0.299) with size of daily area burned (DAB). Burn severity was highly variable, even for the largest (95th percentile) in DAB, suggesting that other variables than fire extent influence the ecological effects of fires. We suggest that these results do not support the prioritization of large runs during fire rehabilitation efforts, since the underlying assumption in this prioritization is a positive relationship between severity and area burned in a day.
Genet, H.; McGuire, A. D.; Johnstone, J. F.; Breen, A. L.; Euskirchen, E. S.; Mack, M. C.; Melvin, A. M.; Rupp, T. S.; Schuur, E. A.; Yuan, F.
Wildfires are one of the main disturbances in high latitude ecosystems and have important consequences for the large stocks of carbon stored in permafrost soils. Fire affects carbon balance directly by burning vegetation and surface organic material and indirectly by influencing post-fire vegetation composition and soil thermal and hydrological regimes. Recent developments of ecosystem models allow a better representation of the effects of fire on organic soil dynamics and the soil environment, but there is a need to better integrate post-fire vegetation succession in these models. Post-fire vegetation regeneration is sensitive to fire consumption of soil organic layer horizons, where high severity burning promotes the establishment of deciduous broadleaf trees. In comparison to conifers, deciduous forests are less flammable, more productive, have higher nutrient turnover, and deeper permafrost. However, deciduous forests generally store less soil carbon than conifer forests. Therefore, the fire-induced shifts in vegetation composition have consequences for ecosystem carbon balance. In this study, we present the development of an ecosystem model that integrates post-fire succession with changes in the structure and function of organic soil horizons to better represent the relationship between fire severity and vegetation succession across the landscape. The model is then used to assess changes in the carbon balance at a 1km resolution, in response to changing fire regime across the landscape in Interior Alaska.
Keeley, J.E.; Fotheringham, C.J.; Baer-Keeley, M.
Plant community diversity, measured as species richness, is typically highest in the early post-fire years in California shrublands. However, this generalization is overly simplistic and the present study demonstrates that diversity is determined by a complex of temporal and spatial effects. Ninety sites distributed across southern California were studied for 5 years after a series of fires. Characteristics of the disturbance event, in this case fire severity, can alter post-fire diversity, both decreasing and increasing diversity, depending on life form. Spatial variability in resource availability is an important factor explaining patterns of diversity, and there is a complex interaction between landscape features and life form. Temporal variability in resource availability affects diversity, and the diversity peak in the immediate post-fire year (or two) appears to be driven by factors different from subsequent diversity peaks. Early post-fire diversity is influenced by life-history specialization, illustrated by species that spend the bulk of their life cycle as a dormant seed bank, which is then triggered to germinate by fire. Resource fluctuations, precipitation in particular, may be associated with subsequent post-fire diversity peaks. These later peaks in diversity comprise a flora that is compositionally different from the immediate post-fire flora, and their presence may be due to mass effects from population expansion of local populations in adjacent burned areas. ?? 2005 Blackwell Publishing Ltd.
White, Angela M.; Manley, Patricia N.; Tarbill, Gina; Richardson, T.L.; Russell, Robin E.; Safford, Hugh D.; Dobrowski, Solomon Z.
Fire is a natural process and the dominant disturbance shaping plant and animal communities in many coniferous forests of the western US. Given that fire size and severity are predicted to increase in the future, it has become increasingly important to understand how wildlife responds to fire and post-fire management. The Angora Fire burned 1243 hectares of mixed conifer forest in South Lake Tahoe, California. We conducted avian point counts for the first 3 years following the fire in burned and unburned areas to investigate which habitat characteristics are most important for re-establishing or maintaining the native avian community in post-fire landscapes. We used a multi-species occurrence model to estimate how avian species are influenced by the density of live and dead trees and shrub cover. While accounting for variations in the detectability of species, our approach estimated the occurrence probabilities of all species detected including those that were rare or observed infrequently. Although all species encountered in this study were detected in burned areas, species-specific modeling results predicted that some species were strongly associated with specific post-fire conditions, such as a high density of dead trees, open-canopy conditions or high levels of shrub cover that occur at particular burn severities or at a particular time following fire. These results indicate that prescribed fire or managed wildfire which burns at low to moderate severity without at least some high-severity effects is both unlikely to result in the species assemblages that are unique to post-fire areas or to provide habitat for burn specialists. Additionally, the probability of occurrence for many species was associated with high levels of standing dead trees indicating that intensive post-fire harvest of these structures could negatively impact habitat of a considerable proportion of the avian community.
Miller, M. E.; Russel, A. M.; Billmire, M.; Endsley, K.; Elliot, W. E.; Robichaud, P. R.; MacDonald, L. H.; Renschler, C. S.
Once the danger posed by an active wildfire has passed, land managers must rapidly assess risks posed by post-fire runoff and erosion due to fire-induced changes in soil properties and the loss of surface cover. Post-fire assessments and proposals to mitigate risks to downstream areas due to flooding, erosion, and sedimentation are typically undertaken by interdisciplinary Burned Area Emergency Response (BAER) teams. One of the first and most important priorities of a BAER team is the development of a burn severity map that reflects the fire-induced changes in both vegetative cover and soils. Currently these maps are known as BARC (Burned Area Reflectance Classification) maps and they are generated from multi-spectral remote sensing data. BAER teams also have access to many erosion modeling tools and datasets, but process-based, spatially explicit models are currently under-utilized relative to simpler, lumped models because they are more difficult to set up and they require the preparation of spatially-explicit data layers such as digital elevation models (DEM), soils, and land cover. We are working to make spatially-explicit modeling easier by preparing large-scale spatial data sets that can be rapidly combined with burn severity maps and then used to quickly run more accurate, process-based models for spatially explicit predictions of post-fire erosion and runoff. A prototype database consisting of 30-m DEM, soil, land cover, and Monitoring Trends in Burn Severity (MTBS) maps for Colorado has been created for use in GeoWEPP (Geo-spatial interface for the Water Erosion Prediction Project) with Disturbed WEPP parameters developed for post-fire conditions. Additional soil data layers have been gathered to support a spatial empirical debris flow model that also utilizes BARC maps. Future plans include developing the dataset to support other models commonly used by BAER teams. The importance of preparing spatial data ahead of time can be illustrated with two
Kotliar, Natasha B; Kennedy, Patricia L; Ferree, Kimberly
The effects of burn severity on avian communities are poorly understood, yet this information is crucial to fire management programs. To quantify avian response patterns along a burn severity gradient, we sampled 49 random plots (2001-2002) at the 17351-ha Cerro Grande Fire (2000) in New Mexico, USA. Additionally, pre-fire avian surveys (1986-1988, 1990) created a unique opportunity to quantify avifaunal changes in 13 pre-fire transects (resampled in 2002) and to compare two designs for analyzing the effects of unplanned disturbances: after-only analysis and before-after comparisons. Distance analysis was used to calculate densities. We analyzed after-only densities for 21 species using gradient analysis, which detected a broad range of responses to increasing burn severity: (I) large significant declines, (II) weak, but significant declines, (III) no significant density changes, (IV) peak densities in low- or moderate-severity patches, (V) weak, but significant increases, and (VI) large significant increases. Overall, 71% of the species included in the after-only gradient analysis exhibited either positive or neutral density responses to fire effects across all or portions of the severity gradient (responses III-VI). We used pre/post pairs analysis to quantify density changes for 15 species using before-after comparisons; spatiotemporal variation in densities was large and confounded fire effects for most species. Only four species demonstrated significant effects of burn severity, and their densities were all higher in burned compared to unburned forests. Pre- and post-fire community similarity was high except in high-severity areas. Species richness was similar pre- and post-fire across all burn severities. Thus, ecosystem restoration programs based on the assumption that recent severe fires in Southwestern ponderosa pine forests have overriding negative ecological effects are not supported by our study of post-fire avian communities. This study illustrates the
Kotliar, N.B.; Kennedy, P.L.; Ferree, K.
The effects of burn severity on avian communities are poorly understood, yet this information is crucial to fire management programs. To quantify avian response patterns along a burn severity gradient, we sampled 49 random plots (2001-2002) at the 17 351-ha Cerro Grande Fire (2000) in New Mexico, USA. Additionally, pre-fire avian surveys (1986-1988, 1990) created a unique opportunity to quantify avifaunal changes in 13 pre-fire transects (resampled in 2002) and to compare two designs for analyzing the effects of unplanned disturbances: after-only analysis and before-after comparisons. Distance analysis was used to calculate densities. We analyzed after-only densities for 21 species using gradient analysis, which detected a broad range of responses to increasing burn severity: (I) large significant declines, (II) weak, but significant declines, (III) no significant density changes, (IV) peak densities in low- or moderate-severity patches, (V) weak, but significant increases, and (VI) large significant increases. Overall, 71% of the species included in the after-only gradient analysis exhibited either positive or neutral density responses to fire effects across all or portions of the severity gradient (responses III-VI). We used pre/post pairs analysis to quantify density changes for 15 species using before-after comparisons; spatiotemporal variation in densities was large and confounded fire effects for most species. Only four species demonstrated significant effects of burn severity, and their densities were all higher in burned compared to unburned forests. Pre- and post-fire community similarity was high except in high-severity areas. Species richness was similar pre- and post-fire across all burn severities. Thus, ecosystem restoration programs based on the assumption that recent severe fires in Southwestern ponderosa pine forests have overriding negative ecological effects are not supported by our study of post-fire avian communities. This study illustrates the
Veraverbeke, Sander; Lhermitte, Stefaan; Verstraeten, Willem; Goossens, Rudi
The temporal sensitivity of the differenced Normalized Burn Ratio (dNBR) to assess burn severity was evaluated for the case of the 2007 Peloponnese (Greece) wildfires. Prior to the analysis, a pixel-based control plot selection procedure was initiated for each burned pixel based on time series similarity of the pre-fire year 2006. Post-fire near infrared (NIR) dramatically dropped immediately post-fire, while the highest MIR reflectance values were reached three weeks after the fire. Both NIR and MIR reflectance showed an increased variability during the wet Mediterranean winter. Due to the process of early vegetation recovery, the burned pixels' NIR reflectance approached the control pixels' values during the productive spring-time. Because of the three weeks post-fire delay in MIR reflectance increase, the NBR drop and dNBR peak were obtained synchronously. Both the standard deviation of the NBR and dNBR were high during winter, as a consequence of the simultaneous increase in NIR and MIR reflectance variability. In spite of the high variation in dNBR during winter, this moment is suboptimal to estimate burn severity due to low rates of image availability and low optimality values. Index performance was clearly lower during winter and spring because vegetation regeneration clearly diminishes the distance in the bi-spectral feature space to which the dNBR is sensitive at the favor of displacements to which the index is insensitive. In contrast, NIR reflectance, MIR reflectance, NBR, dNBR and dNBR optimality changes achieved a maximum three weeks post. Consequently this was the optimal time to estimate burn severity in our case study retaining a maximal degree of information with a high reliability. Conclusions should be verified for other fires and in other ecoregions.
Davies, G. M.; Domènech, R.; Gray, A.; Johnson, P. C. D.
Temperate peatland wildfires are of significant environmental concern but information on their environmental effects is lacking. We assessed variation in burn severity and fuel consumption within and between wildfires that burnt British moorlands in 2011 and 2012. We adapted the composite burn index (pCBI) to provide semi-quantitative estimates of burn severity. Pre- and post-fire surface (shrubs and graminoids) and ground (litter, moss, duff) fuel loads associated with large wildfires were assessed using destructive sampling and analysed using a generalised linear mixed model (GLMM). Consumption during wildfires was compared with published estimates of consumption during prescribed burns. Burn severity and fuel consumption were related to fire weather, assessed using the Canadian Fire Weather Index System (FWI System), and pre-fire vegetation type. pCBI varied 1.6 fold between, and up to 1.7 fold within, wildfires. pCBI was higher where moisture codes of the FWI System indicated drier fuels. Spatial variation in pre- and post-fire fuel load accounted for a substantial proportion of the variance in fuel loads. Average surface fuel consumption was a linear function of pre-fire fuel load. Average ground fuel combustion completeness could be predicted by the Buildup Index. Carbon release ranged between 0.36 and 1.00 kg C m-2. The flammability of ground fuel layers may explain the higher C release-rates seen for wildfires in comparison to prescribed burns. Drier moorland community types appear to be at greater risk of severe burns than blanket-bog communities.
Davies, G. M.; Domènech, R.; Gray, A.; Johnson, P. C. D.
Temperate peatland wildfires are of significant environmental concern but information on their environmental effects is lacking. We assessed variation in burn severity and fuel consumption within and between wildfires that burnt British moorlands in 2011 and 2012. We adapted the Composite Burn Index (pCBI) to provide semi-quantitative estimates of burn severity. Pre- and post-fire surface (shrubs and graminoids) and ground (litter, moss, duff) fuel loads associated with large wildfires were assessed using destructive sampling and analysed using a Generalised Linear Mixed Model (GLMM). Consumption during wildfires was compared with published estimates of consumption during prescribed burns. Burn severity and fuel consumption were related to fire weather, assessed using the Canadian Fire Weather Index System (FWI System), and pre-fire fuel structure. pCBI varied 1.6 fold between, and up to 1.7 fold within, wildfires. pCBI was higher where moisture codes of the FWI System indicated drier fuels. Spatial variation in pre- and post-fire fuel load accounted for a substantial proportion of the variance in fuel loads. Average surface fuel consumption was a linear function of pre-fire fuel load. Average ground fuel combustion completeness could be predicted by the Buildup Index. Carbon release ranged between 0.36 and 1.00 kg C m-2. The flammability of ground fuel layers may explain the higher C release-rates seen for wildfires in comparison to prescribed burns. Drier moorland community types appear to be at greater risk of severe burns than blanket-bog communities.
Meng, R.; Dennison, P. E.; Huang, C.
Forest ecosystems in the Sierra Nevada are greatly influenced by wildfire disturbance. A study of vegetation regrowth following fire is essential for us to better understand and evaluate the effects of disturbances on ecological processes, such as carbon and nitrogen storage, soil erosion, water quality and forest dynamics. The rate of short-term vegetation recovery, as measured by Normalized Difference Vegetation Index (NDVI), was explored following fire over multiple years (1999-2006) in Sierra Nevadan forests. The role of both temporal (e.g. variations in multiple years' precipitation) and landscape factors (e.g. altitude, slope, aspect, pre-fire and immediate post-fire vegetation status, and burn severity) were investigated in explaining the short-term vegetation regrowth following fire using remote sensing on the landscape scale. Our results indicate that spatial-temporal variability existed in the short-term post-fire vegetation regrowth. Pre-fire vegetation status, burn severity, immediate post-fire wet season precipitation and elevation were found to play important roles in short-term post-fire vegetation recovery trends. Consistent with a local forest gap model, our results also corroborate that water availability may be the limiting factor for the post-fire vegetation regrowth in the lower elevation of Sierra Nevadan forests. In the future, post-disturbance vegetation regrowth trends and related controlling environmental factors following various forest disturbances (e.g. insect outbreak and forest harvest) other than wildfire can also be studied and compared using the methodology proposed in this study.
Miller, M. E.; Billmire, M.; Elliot, W. J.; Endsley, K. A.; Robichaud, P. R.
Preparation is key to utilizing Earth Observations and process-based models to support post-wildfire mitigation. Post-fire flooding and erosion can pose a serious threat to life, property and municipal water supplies. Increased runoff and sediment delivery due to the loss of surface cover and fire-induced changes in soil properties are of great concern. Remediation plans and treatments must be developed and implemented before the first major storms in order to be effective. One of the primary sources of information for making remediation decisions is a soil burn severity map derived from Earth Observation data (typically Landsat) that reflects fire induced changes in vegetation and soil properties. Slope, soils, land cover and climate are also important parameters that need to be considered. Spatially-explicit process-based models can account for these parameters, but they are currently under-utilized relative to simpler, lumped models because they are difficult to set up and require spatially-explicit inputs (digital elevation models, soils, and land cover). Our goal is to make process-based models more accessible by preparing spatial inputs before a fire, so that datasets can be rapidly combined with soil burn severity maps and formatted for model use. We are building an online database (http://geodjango.mtri.org/geowepp /) for the continental United States that will allow users to upload soil burn severity maps. The soil burn severity map is combined with land cover and soil datasets to generate the spatial model inputs needed for hydrological modeling of burn scars. Datasets will be created to support hydrological models, post-fire debris flow models and a dry ravel model. Our overall vision for this project is that advanced GIS surface erosion and mass failure prediction tools will be readily available for post-fire analysis using spatial information from a single online site.
Alexander, H. D.; Davydov, S.; Zimov, N.; Mack, M. C.
Global change models predict increased fire activity in boreal forests as climate warms and dries. We hypothesized that fire-driven decreases in soil organic layer (SOL) depth will (1) increase permafrost thaw by reducing the insulating capacity of the SOL and (2) improve seedbed conditions for tree regeneration. Over time, these changes will lead to altered patterns of above- and belowground carbon (C) accumulation. To test these hypotheses, we conducted plot-level experimental burns in July 2012 in a low-density, mature larch stand near the Northeast Science Station in Cherskii, Siberia. Dried fuels of naturally occurring vegetation were added to plots to achieve four burn severity treatments based on residual SOL depths: control, low (> 8 cm), moderate (5-8 cm), and high severity (2-5 cm). Pre-fire and during two growing seasons post-fire, we measured thaw depth, soil moisture, and soil temperature to determine severity effects on permafrost thaw. We also sowed larch seeds in fall 2012 and quantified germination rates the following growing season. By 1 wk post-fire, thaw depth was 15-25 cm deeper in plots burned at high severity (55 cm) compared to other treatments (30-40 cm). These differences in thaw depth with burn severity were maintained during the subsequent growing season and were associated with increased soil temperature and moisture. Larch regeneration was 10x higher on severely burned plots than those unburned. Our findings highlight the potential for increased fire severity to degrade permafrost and alter successional dynamics and patterns of C accumulation.
Wohlgemuth, P. M.; Beyers, J. L.; Robichaud, P. R.
High severity wildfire can make landscapes susceptible to accelerated erosion that may retard resource recovery. High levels of erosion can also threaten life, property, and infrastructure in downstream human communities. Land managers often use mitigation measures on the burned hillside slopes to control post-fire sediment fluxes both as the first step in post-fire restoration and to protect off-site human developments. Aerial hydromulch, a slurry of paper or wood fiber with tackifiers and other amendments that dries to a permeable crust, is a relatively new erosion control treatment that has not been rigorously field-tested in wildland settings. Concerns have been raised over the ability of aerial hydromulch to reduce hillslope erosion as well as its potential for negative effects on post-fire ecosystem recovery. Since 2007 we have measured sediment fluxes and vegetation development on plots treated operationally with aerial hydromulch and compared them to untreated controls after three separate wildfires in southern California. These study plots, located on steep slopes with coarse upland soils previously covered with dense mixed chaparral vegetation, were monitored with silt fences to trap eroded sediment. Meter-square quadrats were used to measure ground and vegetation cover. Although dependent on rainfall and site characteristics, surface erosion on untreated plots generally attenuated sharply with years since burning. We found that aerial hydromulch did reduce bare ground on the treated plots and that this cover persisted through the first post-fire winter rainy season. For the initial year after a fire, aerial hydromulch reduced hillslope erosion from small and medium rainstorms, but not during an extremely high intensity rainfall event. Hydromulch had no effect on regrowing plant cover, shrub seedling density, or species richness. Thus, in chaparral ecosystems aerial hydromulch appears to be an effective post-fire erosion control measure that is
McKinley, R.; Clark, J.; Lecker, J.
In 2009, the Victoria Department of Sustainability and Environment estimated approximately 430,000 hectares of Victoria Australia were burned by numerous bushfires. Burned Area Emergency Response (BAER) teams from the United States were deployed to Victoria to assist local fire managers. The U.S. Geological Survey Earth Resources Observation and Science Center (USGS/EROS) and U.S. Forest Service Remote Sensing Applications Center (USFS/RSAC) aided the support effort by providing satellite-derived "soil burn severity " maps for over 280,000 burned hectares. In the United States, BAER teams are assembled to make rapid assessments of burned lands to identify potential hazards to public health and property. An early step in the assessment process is the creation of a soil burn severity map used to identify hazard areas and prioritize treatment locations. These maps are developed primarily using Landsat satellite imagery and the differenced Normalized Burn Ratio (dNBR) algorithm.
Wu, Zhiwei; He, Hong S.; Liang, Yu; Cai, Longyan; Lewis, Bernard J.
Fire is a dominant process in boreal forest landscapes and creates a spatial patch mosaic with different burn severities and age classes. Quantifying effects of vegetation and topography on burn severity provides a scientific basis on which forest fire management plans are developed to reduce catastrophic fires. However, the relative contribution of vegetation and topography to burn severity is highly debated especially under extreme weather conditions. In this study, we hypothesized that relationships of vegetation and topography to burn severity vary with fire size. We examined this hypothesis in a boreal forest landscape of northeastern China by computing the burn severity of 24 fire patches as the difference between the pre- and post-fire Normalized Difference Vegetation Index obtained from two Landsat TM images. The vegetation and topography to burn severity relationships were evaluated at three fire-size levels of small (<100 ha, n = 12), moderate (100-1,000 ha, n = 9), and large (>1,000 ha, n = 3). Our results showed that vegetation and topography to burn severity relationships were fire-size-dependent. The burn severity of small fires was primary controlled by vegetation conditions (e.g., understory cover), and the burn severity of large fires was strongly influenced by topographic conditions (e.g., elevation). For moderate fires, the relationships were complex and indistinguishable. Our results also indicated that the pattern trends of relative importance for both vegetation and topography factors were not dependent on fire size. Our study can help managers to design fire management plans according to vegetation characteristics that are found important in controlling burn severity and prioritize management locations based on the relative importance of vegetation and topography.
Hyde, Kevin; Woods, Scott W.; Donahue, Jack
The loss of surface vegetation and reduced infiltration caused by wildfires can trigger gully rejuvenation, resulting in damage to downstream aquatic resources and risk to human life and property. We developed a spatially explicit metric of burn severity — the Burn Severity Distribution Index (BSDI) — and tested its ability to predict post-fire gully rejuvenation in 1st and 2nd order basins burned in the 2000 Valley Complex fires in the Sapphire Mountains of western Montana. The BSDI was derived from burn severity data interpreted from Landsat 7 satellite imagery using the Normalized Burn Ratio (NBR) method, and ranged from 0.0 for completely unburned basins to 4.0 for basins burned entirely at high severity. In July 2001 rainstorms with peak 30-minute intensities of up to 17 mm h - 1 triggered gully rejuvenation in 66 of the 171 basins examined. The frequency of gully rejuvenation was higher in basins with higher BSDI values, increasing from zero for basins with a BSDI less than 1.3 to 67% for basins with a BSDI greater than 3.0. Binary logistic regression indicated that BSDI was a more significant predictor of gully rejuvenation than basin morphometric variables. The absence of gully rejuvenation in several basins with a high BSDI was attributed to low gradient, dense riparian vegetation, or concentration of high burn severity at lower elevations in the basin. The presence of gully rejuvenation in several basins with a low BSDI was associated with false negative NBR classification errors in northwest aspects, and concentration of severe burn impacts in the drainage headslopes. BSDI is a useful metric for predicting gully rejuvenation after wildfire. The use of the BSDI in Burned Area Emergency Response team assessments could improve the planning, implementation, and monitoring of burned area recovery treatments.
Zheng, Zhong; Zeng, Yongnian; Li, Songnian; Huang, Wei
Remotely sensed data have already become one of the major resources for estimating the burn severity of forest fires. Recently, Land Surface Temperature (LST) calculated from remote sensing data has been considered as a potential indicator for estimating burn severity. However, using the LST-based index alone may not be sufficient for estimating burn severity in the areas that has unburned trees and vegetation. In this paper, a new index is proposed by considering LST and enhanced vegetation index (EVI) together. The accuracy of the proposed index was evaluated by using 264 composite burn index (CBI) field sample data of the five fires across different regional eco-type areas in the Western United States. Results show that the proposed index performed equally well for post-fire areas covered with both sparse vegetation and dense vegetation and relatively better than some commonly-used burn severity indices. This index also has high potential of estimating burn severity if more accurate surface temperatures can be obtained in the future.
Youberg, A.; Koestner, K. A.; Schiefer, E.; Neary, D. G.
Several large, devastating wildfires occurred in Arizona during the past 2 years, after a 4-year period without any large wildfires. In June, 2010, the human-caused Schultz Fire near Flagstaff burned 6,100 ha of mostly steep terrain. Subsequent rains from the 4th wettest monsoon on record produced numerous debris flows, significant erosion, and substantial flooding of the downslope residential areas. In May and June of 2011, 3 very large human-caused wildfires (Wallow, Horseshoe 2, and Monument Fires) burned over 320,000 ha, posing serious threats to communities below burned slopes. The Burned Area Emergency Response (BAER) teams, in need of a rapid method to assess the potential for post-fire debris flows, turned to models developed by the USGS for this purpose [Cannon and others, 2010, GSA Bull, 122(1-2), 127-144]. These models, while providing quick results, have not been evaluated for use in Arizona's varied physiographic provinces. Here we use data from the Schultz Fire to compare basin responses with those predicted by the USGS post-fire debris-flow models. Data from the Schultz Fire includes detailed field documentation of debris-flow occurrence and runout distances, 1:12,000 stereo aerial photographs, high-resolution digital elevation models (DEMs) and tipping-bucket rainfall data. These data document debris-flow producing storms, basin response, and the extent of debris-flow runout, and provide estimates of debris-flow volumes. The hydrologic responses from 30 small, steep, upper basins burned by the Schultz Fire were assessed for debris or flood flow occurrences. Nineteen basins produced debris flows during a July 20th storm that had a peak 10-minute intensity of 24 mm. A second storm on August 16th, with a peak 10-minute intensity of 15 mm, produced additional debris flows in several of the same basins. Of the 30 basins assessed, 19 were completely burned; four at high severity and 12 at moderate to high severity. The basin with the smallest burned area
North America's western forests are experiencing wildfire and mountain pine beetle (MPB) disturbances that are unprecedented in the historic record, but it remains unclear whether and how MPB infestation influences post-infestation fire behavior. The 2012 High Park Fire burned in an area that's estimated to have begun a MPB outbreak cycle within five years before the wildfire, resulting in a landscape in which disturbance interactions can be studied. A first step in studying these interactions is mapping regions of beetle infestation and post-fire disturbance. We implemented an approach for mapping beetle infestation and burn severity using as source data three 5 m resolution RapidEye satellite images (two pre-fire, one post-fire). A two-tiered methodology was developed to overcome the spatial limitations of many classification approaches through explicit analyses at both pixel and plot level. Major land cover classes were photo-interpreted at the plot-level and their spectral signature used to classify 5 m images. A new image was generated at 25 m resolution by tabulating the fraction of coincident 5 m pixels in each cover class. The original photo interpretation was then used to train a second classification using as its source image the new 25 m image. Maps were validated using k-fold analysis of the original photo interpretation, field data collected immediately post-fire, and publicly available classifications. To investigate the influence of pre-fire beetle infestation on burn severity within the High Park Fire, we fit a log-linear model of conditional independence to our thematic maps after controlling for forest cover class and slope aspect. Our analysis revealed a high co-occurrence of severe burning and beetle infestation within high elevation lodgepole pine stands, but did not find statistically significant evidence that infected stands were more likely to burn severely than similar uninfected stands. Through an inspection of the year-to-year changes in
Woody plants can cause localized increases in resources (i.e. resource islands) that can persist after fire and create a heterogeneous environment for restoration. We tested the hypothesis that burned sagebrush subcanopies would have increased seedling establishment and performance of post-fire see...
Kotliar, N.B.; Hejl, S.J.; Hutto, R.L.; Saab, V.A.; Melcher, C.P.; McFadzen, M.E.
Historically, fire was one of the most widespread natural disturbances in the western United States. More recently, however, significant anthropogenic activities, especially fire suppression and silvicultural practices, have altered fire regimes; as a result, landscapes and associated communities have changed as well. Herein, we review current knowledge of how fire and post-fire salvaging practices affect avian communities in conifer-dominated forests of the western United States. Specifically, we contrast avian communities in (1) burned vs. unburned forest, and (2) unsalvaged vs. salvage-logged burns. We also examine how variation in burn characteristics (e.g., severity, age, size) and salvage logging can alter avian communities in burns. Of the 41 avian species observed in three or more studies comparing early post-fire and adjacent unburned forests, 22% are consistently more abundant in burned forests, 34% are usually more abundant in unburned forests, and 44% are equally abundant in burned and unburned forests or have varied responses. In general, woodpeckers and aerial foragers are more abundant in burned forest, whereas most foliage-gleaning species are more abundant in unburned forests. Bird species that are frequently observed in stand-replacement burns are less common in understory burns; similarly, species commonly observed in unburned forests often decrease in abundance with increasing burn severity. Granivores and species common in open-canopy forests exhibit less consistency among studies. For all species, responses to fire may be influenced by a number of factors including burn severity, fire size and shape, proximity to unburned forests, pre- and post-fire cover types, and time since fire. In addition, post-fire management can alter species' responses to burns. Most cavity-nesting species do not use severely salvaged burns, whereas some cavity-nesters persist in partially salvaged burns. Early post-fire specialists, in particular, appear to prefer
Perreault, L. M.; Yager, E. M.; Aalto, R. E.
Wildfires can profoundly affect hillslope erosion rates by altering the physical and chemical attributes of the soil and denuding stabilizing vegetation. Increased hillslope erosion can raise stream channel sediment loads, which can change the channel morphology and impact aquatic habitat structure and downstream dam sedimentation. Current climate change predictions for the intermountain West forecast more frequent and severe droughts, and correspondingly more severe fire events, increasing the potential for post-fire erosion. Despite the widespread impacts of such erosion events, hillslope erosion processes remain poorly understood. Thus, to better understand these processes, we measure hillslope erosion rates in the mountainous terrain of central Idaho following a large, severe 2007 forest fire. Specifically, we use radionuclide (Lead-210, Cesium-137) inventories to quantify hillslope erosion rates in several watersheds with different burn severity (severe, moderate and unburned), on different aspects (north vs. south facing slopes), and on different hillslope forms (concave vs. convex profiles). In mid-latitude areas of high relief, aspect strongly influences the amount of solar radiation received and thus impacts local moisture conditions, vegetation and soil development, all of which can affect soil erosion rates. Hillslope form may influence the dominant erosion process, with convex profiles characterized by diffusive erosion, and concave profiles potentially enabling more overland flow, rill and gully formation. These variables, in addition to burn severity, are therefore likely to affect erosion rates. Our study quantifies the effect of burn severity, hillslope form, and aspect on the rates and processes of post-fire hillslope erosion. In addition, our study offers insight into the relatively novel use of radionuclide inventories to measure post-wildfire erosion rates. An improved quantitative understanding of hillslope erosion processes would enable us to
In addition to recent advances in burn patient care techniques such as maintaining warm circumambient temperature, the early excision of wounds, and the use of closed dressing, providing nutrition support through early feeding has proven instrumental in greatly increasing the survival rate of burn patients. Severe burns complicated by many factors initiate tremendous physiological stress that leads to postburn hypermetabolism that includes enhanced tissue catabolism, the loss of muscle mass, and decreases in the body's reservoirs of protein and energy. These problems have become the focus of burn therapy. Treating severe burns aims not only to enhance survival rates but also to restore normal bodily functions as completely as possible. Recent research evaluating the application of anabolic agents and immune-enhance formula for severe burns therapy has generated significant controversy. Inadequate caloric intake is one of the main differences among the related studies, with the effect of many special nutrients such as bran acid amides not taken into consideration. Therefore, considering the sufficiency of caloric and protein intake is critical in assessing effectiveness. Only after patients receive adequate calories and protein may the effect of special nutrients such as glutamine and supplements be evaluated effectively. PMID:26813059
Renau, Ana Isabel; García-Vidal, Carolina; Salavert, Miguel
Currently, there are few studies on candidaemia in the severely burned patient. These patients share the same risk factors for invasive fungal infections as other critically ill patients, but have certain characteristics that make them particularly susceptible. These include the loss of skin barrier due to extensive burns, fungal colonisation of the latter, and the use of hydrotherapy or other topical therapies (occasionally with antimicrobials). In addition, the increased survival rate achieved in recent decades in critically burned patients due to the advances in treatment has led to the increase of invasive Candida infections. This explains the growing interest in making an earlier and more accurate diagnosis, as well as more effective treatments to reduce morbidity and mortality of candidaemia in severe burned patients. A review is presented on all aspects of the burned patient, including the predisposition and risk factors for invasive candidiasis, pathogenesis of candidaemia, underlying immunodeficiency, local epidemiology and antifungal susceptibility, evolution and prognostic factors, as well as other non-Candida yeast infections. Finally, we include specific data on our local experience in the management of candidaemia in severe burned patients, which may serve to quantify the problem, place it in context, and offer a realistic perspective. PMID:27395025
Veraverbeke, S.; Hook, S.
Fire severity data are of paramount importance to (i) organize post-fire rehabilitation plans and (ii) reduce uncertainties in wildfire emission estimates by allowing spatio-temporal variability in burning efficiency values. We have used a Landsat Thematic Mapper (TM) image to assess fire severity of the large 2011 Wallow fire in Arizona, USA. The Normalized Burn Ratio (NBR), differenced NBR (dNBR), Relative dNBR (RdNBR) and the char fraction estimated by Spectral Mixture Analysis (SMA) were evaluated. Geo Composite Burn Index (GeoCBI) and vegetation mortality data were used as ground truth. Of all remotely sensed measures tested the dNBR had the highest performance (GeoCBI-dNBR R2 = 0.84 and % black trees-dNBR R2 = 0.91), which supports the operational use of the dNBR for post-fire management. Without initial calibration with field data, however, dNBR values lack biophysical meaning. The SMA-derived char fraction also had moderate-high correlations with the field data (GeoCBI-char fraction R2 = 0.66 and % black trees-char fraction R2 = 0.82). The char fractions provide a direct mechanistic link with the fire processes that occurred on the ground. Such data have big potential to adjust burning efficiency values. This is of great importance to reduce uncertainties in wildfire emission estimates.
Hart, David W.; Wolf, Steven E.; Ramzy, Peter I.; Chinkes, David L.; Beauford, Robert B.; Ferrando, Arny A.; Wolfe, Robert R.; Herndon, David N.
Objective To explore the hypothesis that oxandrolone may reverse muscle catabolism in cachectic, critically ill pediatric burn patients. Summary Background Data Severe burn causes exaggerated muscle protein catabolism, contributing to weakness and delayed healing. Oxandrolone is an anabolic steroid that has been used in cachectic hepatitis and AIDS patients. Methods Fourteen severely burned children were enrolled during a 5-month period in a prospective cohort analytic study. There was a prolonged delay in the arrival of these patients to the burn unit for definitive care. This neglect of skin grafting and nutritional support resulted in critically ill children with significant malnutrition. On arrival, all patients underwent excision and skin grafting and received similar clinical care. Subjects were studied 5 to 7 days after admission, and again after 1 week of oxandrolone treatment at 0.1 mg/kg by mouth twice daily or no pharmacologic treatment. Muscle protein kinetics were derived from femoral arterial and venous blood samples and vastus lateralis muscle biopsies during a stable isotope infusion. Results Control and oxandrolone subjects were similar in age, weight, and percentage of body surface area burned. Muscle protein net balance decreased in controls and improved in the oxandrolone group. The improvement in the oxandrolone group was associated with increased protein synthesis efficiency. Muscle protein breakdown was unchanged. Conclusions In burn victims, oxandrolone improves muscle protein metabolism through enhanced protein synthesis efficiency. These findings suggest the efficacy of oxandrolone in impeding muscle protein catabolism in cachectic, critically injured children. PMID:11303139
Coban, Yusuf Kenan
In the last two decades, much progress has been made in the control of burn wound infection and nasocomial infections (NI) in severely burned patients. The continiually changing epidemiology is partially related to greater understanding of and improved techniques for burn patient management as well as effective hospital infection control measures. With the advent of antimicrobial chemotherapeutic agents, infection of the wound site is now not as common as, for example, urinary and blood stream infections. Universal application of early excision of burned tissues has made a substantial improvement in the control of wound-related infections in burns. Additionally, the development of new technologies in wound care have helped to decrease morbidity and mortality in severe burn victims. Many examples can be given of the successful control of wound infection, such as the application of an appropriate antibiotic solution to invasive wound infection sites with simultaneous vacuum-assisted closure, optimal preservation of viable tissues with waterjet debridement systems, edema and exudate controlling dressings impregnated with Ag (Silvercel, Aquacell-Ag). The burned patient is at high risk for NI. Invasive interventions including intravenous and urinary chateterization, and entubation pose a further risk of NIs. The use of newly designed antimicrobial impregnated chateters or silicone devices may help the control of infection in these immunocomprimised patients. Strict infection control practices (physical isolation in a private room, use of gloves and gowns during patient contact) and appropriate empirical antimicrobial therapy guided by laboratory surveillance culture as well as routine microbial burn wound culture are essential to help reduce the incidance of infections due to antibiotic resistant microorganisms. PMID:24701406
Roock, Sophie D; Deleuze, Jean-Paul; Rose, Thomas; Jennes, Serge; Hantson, Philippe
Assault chemical burns are uncommon in northern Europe. Besides local toxicity, systemic manifestations are possible after strong acid exposure. A 40-year-old woman was admitted 1 h after a criminal assault with sulfuric acid. The total burned surface area was 35%, third degree. Injury was due to sulfuric acid (measured pH 0.9) obtained from a car battery. Immediate complications were obstructive dyspnea and metabolic acidosis. The admission arterial pH was 6.92, with total bicarbonate 8.6 mEq/l and base deficit 23.4 mEq/l. The correction of metabolic acidosis was achieved after several hours by the administration of bicarbonate and lactate buffers. The patient developed several burns-related complications (sepsis and acute renal failure). Cutaneous projections of strong acids may cause severe metabolic acidosis, particularly when copious irrigation and clothes removal cannot be immediately performed at the scene. PMID:22787349
Hunter, M.E.; Omi, P.N.; Martinson, E.J.; Chong, G.W.
Establishment and spread of non-native species following wildfires can pose threats to long-term native plant recovery. Factors such as disturbance severity, resource availability, and propagule pressure may influence where non-native species establish in burned areas. In addition, pre- and post-fire management activities may influence the likelihood of non-native species establishment. In the present study we examine the establishment of non-native species after wildfires in relation to native species richness, fire severity, dominant native plant cover, resource availability, and pre- and post-fire management actions (fuel treatments and post-fire rehabilitation treatments). We used an information-theoretic approach to compare alternative hypotheses. We analysed post-fire effects at multiple scales at three wildfires in Colorado and New Mexico. For large and small spatial scales at all fires, fire severity was the most consistent predictor of non-native species cover. Non-native species cover was also correlated with high native species richness, low native dominant species cover, and high seeded grass cover. There was a positive, but non-significant, association of non-native species with fuel-treated areas at one wildfire. While there may be some potential for fuels treatments to promote non-native species establishment, wildfire and post-fire seeding treatments seem to have a larger impact on non-native species. ?? IAWF 2006.
Loboda, T. V.; Jenkins, L. K.; French, N. H.; Bourgeau-Chavez, L. L.
relationships with CBI compared to BSI (exceeding R2 of 0.8 in 10 and 4 instances for CBI and BSI, respectively) for single-date assessments. Similarly, for multi-date differenced assessments, the R2 between CBI and various Landsat-based indices exceeded 0.8 in 76 instances compared to only 20 instances for BSI. However, there are considerable differences between the timing of image acquisition post fire when the relationships between satellite observations and CBI or BSI are the closest as well and indices which field assessments of burn severity appear to be best correlated with. CBI produces closest relationships with near infrared, short-wave infrared at 1.5μm, relative differenced Normalized Burn Ratio, and Tasseled Cap Greenness indices when the post-fire image is acquired immediately after the fire event irrespective of the pre-burn date selection. In contrast, the relationship between BSI and spectral indices peaks when pre- and post-burn indices are computed from images preceding the full green-up conditions (i.e. late May imagery), with Tasseled Cap Brightness showing the closest relationship. Although on average CBI outperforms BSI, BSI produces closer relationships to spectral indices than CBI indicating that the two field assessments provide complimentary information which can be related to biophysical properties of impacted surface.
Kolden, Crystal A.; Rogan, John
Wildfires are historically infrequent in the arctic tundra, but are projected to increase with climate warming. Fire effects on tundra ecosystems are poorly understood and difficult to quantify in a remote region where a short growing season severely limits ground data collection. Remote sensing has been widely utilized to characterize wildfire regimes, but primarily from the Landsat sensor, which has limited data acquisition in the Arctic. Here, coarse-resolution remotely sensed data are assessed as a means to quantify wildfire burn severity of the 2007 Anaktuvuk River Fire in Alaska, the largest tundra wildfire ever recorded on Alaska's North Slope. Data from Landsat Thematic Mapper (TM) and downsampled Moderate-resolution Imaging Spectroradiometer (MODIS) were processed to spectral indices and correlated to observed metrics of surface, subsurface, and comprehensive burn severity. Spectral indices were strongly correlated to surface severity (maximum R2 = 0.88) and slightly less strongly correlated to substrate severity. Downsampled MODIS data showed a decrease in severity one year post-fire, corroborating rapid vegetation regeneration observed on the burned site. These results indicate that widely-used spectral indices and downsampled coarse-resolution data provide a reasonable supplement to often-limited ground data collection for analysis and long-term monitoring of wildfire effects in arctic ecosystems.
Shi, H.; Hawbaker, T. J.; Rollins, M. G.; Volegmann, J. E.; Yang, L.
The U.S. Geological Survey (USGS) is prototyping a methodology to conduct an assessment of current carbon stocks and fluxes, and potential increases for ecological carbon sequestration under a range of climate change, policy and economic scenarios, as required by Section 712 of the Energy Independence and Security Act (EISA) of 2007. Disturbances, especially fire, are recognized as having a critical role in carbon dynamics and EISA explicitly requires accounting for their potential impacts. The quantity of carbon released from fires and post-fire carbon sequestration rates are both related to burn severity. However, models explaining and predicting patterns of burn severity are lacking, but needed for long-term assessments quantifying how carbon dynamics will change in response to climate change and future disturbance regimes. To address this knowledge gap, we first quantified changes in field-measured biomass pools according to vegetation types and burn severity categories. We then, constructed statistical models predicting burn severity based on a suite of topographic, climate, and biophysical variables. We selected fires from the Monitoring Trends in Burn Severity (MTBS) database that burned between 1989 and 2007 across representative ecosystems of the U.S. The MTBS data were combined with plot data from the LANDFIRE field reference database where pre- and post-disturbance measurements were made to summarize changes in biomass pools by burn severity and vegetation type. Second, we built statistical models relating the burn severity patterns to LANDFIRE vegetation types, satellite-derived land surface phenology, topographic, and climate variables. We found that the burn severity data captured disturbance-driven changes in above-ground biomass pools well. In the predictive models, vegetation type and fuel loading (measured through land surface phenology) explained the largest amount of variability in burn severity patters; however, climate and topography also had
Ruiz-Castilla, Mireia; Roca, Oriol; Masclans, Joan R.; Barret, Joan P.
ABSTRACT The pathophysiology of burn injuries is tremendously complex. A thorough understanding is essential for correct treatment of the burned area and also to limit the appearance of organ dysfunction, which, in fact, is a key determinant of morbidity and mortality. In this context, research into biomarkers may play a major role. Biomarkers have traditionally been considered an important area of medical research: the measurement of certain biomarkers has led to a better understanding of pathophysiology, while others have been used either to assess the effectiveness of specific treatments or for prognostic purposes. Research into biomarkers may help to improve the prognosis of patients with severe burn injury. The aim of the present clinical review is to discuss new evidence of the value of biomarkers in this setting. PMID:26771933
Riedel, G; Becker, S; Steen, M
A 47-year-old man sustained a 31% TBSA burn injury. In spite of early escharectomy and mesh-graft-transplantation the patient suffered a septicaemic phase in the first week, which was treated by a specific antibiotic. Five weeks after the burn injury a cervical spondylodiscitis was diagnosed. Immediate wound debridement, ventral and dorsal spondylodesis with a tricortical bone-graft from the left iliac crest and titanium plates and specific antibiotic therapy led to the stabilization and healing of the cervical spinal column. The spondylodiscitis was microbiologically proved to be hematogenous after spread of Staphylococcus aureus from the blood in the early septicaemic phase. Swab culture from the burn surface wound, infected vertebrae and blood during the septicaemic phase revealed coagulase positive S. aureus. The aetiology, predisposing factors and management of this rare, but recognized, complication of major burns are discussed. Case features of this patient are compared with the single site's reported case of hematogenous cervical spondylodiscitis after severe burn injury. PMID:11718988
Fu, Yang; Xie, Bing; Ben, DaoFeng; Lv, KaiYang; Zhu, ShiHui; Lu, Wei; Tang, HongTai; Cheng, DaSheng; Ma, Bing; Wang, GuangYi; Xiao, ShiChu; Wang, GuangQing; Xia, ZhaoFan
The present study aims to define the trend of time related changes with local bacterial alteration of bacterial resistance in severe burns in our burn center during a 12-year period. Retrospective analysis of microbiological results on severely burned wounds between 1998 and 2009 was carried out. A study of 3615 microbial isolates was performed. Staphylococcus aureus was the most commonly isolated pathogen (38.2%) followed by A. baumannii (16.2%), Streptococcus viridans (11.4%), Pseudomonas aeruginosa (10.4%), coagulase-negative staphylococci (CNS, 9.2%). The species ratios of S. aureus and A. baumannii increased significantly from 1st to 8th week of hospitalization, while those of Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci decreased during the same period. Bacterial resistance rates were compared between the periods 1998-2003 and 2004-2009. Vancomycin remained as the most sensitive antibiotic in S. aureus including methicillin-resistant S. aureus (MRSA). It was very likely that the majority of infections caused by Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci occurred in the early stage of burn course and the majority of infections caused by A. baumannii occurred 4 weeks after admission. The use of different antibiotics was probably the major contributor to these trends. PMID:22100426
Veraverbeke, S.; Lhermitte, S.; Verstraeten, W. W.; Goossens, R.
Burn severity is an important parameter in post-fire management. It incorporates both the direct fire impact (vegetation depletion) and ecosystem responses (vegetation regeneration). From a remote sensing perspective, burn severity is traditionally estimated using Landsat's differenced normalized burn ratio (dNBR). In this case study of the large 2007 Peloponnese (Greece) wildfires, Landsat dNBR estimates correlated reasonably well with Geo composite burn index (GeoCBI) field data of severity ( R2 = 0.56). The usage of Landsat imagery is, however, restricted by cloud cover and image-to-image normalization constraints. Therefore a multi-temporal burn severity approach based on coarse spatial, high temporal resolution moderate resolution imaging spectroradiometer (MODIS) imagery is presented in this study. The multi-temporal dNBR (dNBR MT) is defined as the 1-year integrated difference between burned pixels and their unique control pixels. These control pixels were selected based on time series similarity and spatial context and reflect how burned pixels would have behaved in the case no fire had occurred. Linear regression between downsampled Landsat dNBR and dNBR MT estimates resulted in a moderate-high coefficient of determination R2 = 0.54. dNBR MT estimates are indicative for the change in vegetation productivity due to the fire. This change is considerably higher for forests than for more sparsely vegetated areas like shrub lands. Although Landsat dNBR is superior for spatial detail, MODIS-derived dNBR MT estimates present a valuable alternative for burn severity mapping at continental to global scale without image availability constraints. This is beneficial to compare trends in burn severity across regions and time. Moreover, thanks to MODIS's repeated temporal sampling, the dNBR MT accounts for both first- and second-order fire effects.
Tsinnajinnie, L.; Frisbee, M. D.; Wilson, J. L.
Semiarid, mountainous watersheds are particularly susceptible to wildfires due to their dense forests and dry conditions. These watersheds are critically important sources of water and habitat for human and ecological communities in an otherwise water-scarce environment. Forest fires severely impact these watersheds through loss of vegetation, increases in erosion, decreases in water quality, and decreases in recharge. In addition, soil hydrophobicity, overland runoff, and erosion in post-fire watersheds create conditions where it is difficult for burned areas to re-vegetate within the months following a wildfire. What role do perennial springs play in post-fire re-vegetation? We hypothesize that revegetation originates around perennial springs since the springs and spring-runs are continual sources of water where new seeds can sprout and where burned vegetation can recover. We test this hypothesis in a snow-dominated, semiarid, mountainous watershed in the Chuska Mountains, located on the Navajo Nation in New Mexico and Arizona, following a wildfire that occurred in June 2014. NDVI was estimated in the watershed before and after the June 2014 fire using remotely sensed data. Photographs from digital trail cameras were used to capture the growth of vegetation/absence of growth on burned slopes with/without springs following the fire. The remote sensing data and trail camera photos indicate that revegetation is concentrated around springs. Springs act as "fountains" for regrowth of vegetation in the watershed following wildfires since they are dependable sources of clean water in a post-fire landscape commonly characterized by decreased infiltration and decreased water quality. An improved understanding of the role of springs in post-wildfire revegetation may enhance and prioritize watershed restoration and protection practices following a wildfire.
Solomon, J R
Adequate nutrition in the severely burned child often determines the morbidity and mortality and its supervision demands a high priority in the management of the burn injury. A disciplined, detailed programme is required, but this is often neglected. The hypermetabolism experienced in the severe burn may require a calorie intake up to 2 1/2 times normal, and in the growing child, with extra requirements, a negative balance can easily eventuate if careful management is not instituted. A daily metabolic plan provides firstly, the basic calories and protein per kilogram depending on age as for a normal child and, secondly additional requirements depending on the surface area of the burn. With such a programme the weakness of treating all children, whatever their age, on the same formula related only to surface area burn, is overcome. Parenteral nutrition is commenced as soon as the shock phase has been controlled and is continued until enteral intake by gastric tube is sufficient to cover the requirements. Such tube feeding requires the selection of an isotonic liquid diet so as so limit the possibility of diarrhoea. Isocal (Mead Johnson) has been found generally acceptable. Gradually as the patient recovers, oral intake is introduced and the child returns home on a normal nutritional diet, expectantly without weight loss and even with some weight gain, which befits any normal child under treatment for some months. Preburn nutrition, disease and infection, hyperthermia, hypothermia, evaporative water loss, active exercise, psychological well being, social state, early skin cover and limitation of stress are important aspects affecting metabolism and require careful supervision and management. The limitation of metabolism is as important as increasing the caloric intake and this is exemplified at the time of operation, which should be as nonstressful as possible. Every two weeks an adjusted assessment is made of the burned area still to be grafted and the caloric
Nourbakhshbeidokhti, S.; Kinoshita, A. M.; Chin, A.
Wildfires have potential to significantly alter soil properties and vegetation within watersheds. These alterations often contribute to accelerated erosion, runoff, and sediment transport in stream channels and hillslopes. This research applies repeated Terrestrial Laser Scanning (TLS) Light Detection and Ranging (LiDAR) to stream reaches within the Pike National Forest in Colorado following the 2012 Waldo Canyon Fire. These scans allow investigation of the relationship between sediment delivery and environmental characteristics such as precipitation, soil burn severity, and vegetation. Post-fire LiDAR images provide high resolution information of stream channel changes in eight reaches for three years (2012-2014). All images are processed with RiSCAN PRO to remove vegetation and triangulated and smoothed to create a Digital Elevation Model (DEM) with 0.1 m resolution. Study reaches with two or more successive DEM images are compared using a differencing method to estimate the volume of sediment erosion and deposition. Preliminary analysis of four channel reaches within Williams Canyon and Camp Creek yielded erosion estimates between 0.035 and 0.618 m3 per unit area. Deposition was estimated as 0.365 to 1.67 m3 per unit area. Reaches that experienced higher soil burn severity or larger rainfall events produced the greatest geomorphic changes. Results from LiDAR analyses can be incorporated into post-fire hydrologic models to improve estimates of runoff and sediment yield. These models will, in turn, provide guidance for water resources management and downstream hazards mitigation.
MacDonald, Lee; Wagenbrenner, Joe; Nelson, Peter; Brogan, Dan
Over the past 10-15 years tremendous advances have been made in understanding the effects of fires on runoff and erosion processes, the effectiveness of various post-fire rehabilitation treatments, and the prediction of these changes. The problem is that nearly all of this work has been done at the plot and hillslope scale, while it is the larger-scale issues of flooding, water quality, and sedimentation that are of primary concern to resource managers and the public. In most cases these larger-scale changes are predicted either by simple lumped models, such as the curve number technique, or by summing up the hillslope-scale responses. These approaches can greatly overestimate the downstream effects because they do not account for the spatial variability of rainfall or the complexities of routing and storage. While post-fire stormflows may be efficiently routed downstream, our observations from fires across the western US indicate very large differences in the amount of sediment delivered to downstream areas. As one example, a large storm after the 2012 High Park fire near Fort Collins generated huge amounts of sediment, but relatively little of this was delivered to the Cache la Poudre River; in the case of the 2002 Hayman fire near Denver even moderate-sized storms delivered enough sand and fine gravel to temporarily dam up the South Platte River and over time around 750,000 m3 of sediment was deposited into Strontia Springs Reservoir. In this paper we hypothesize that relatively simple set of tools can greatly improve our ability to predict post-fire runoff and sediment delivery at the watershed scale (5-100 km2). In areas dominated by convective storms post-fire flood risks should be modified according to the size of those storms relative to the upslope contributing area and extent of high or moderate burn severity. The potential delivery of post-fire sediment can be improved by combining the predicted flood risk with empirical adjustments based on valley
Blauvelt, K. J.; Nolin, A. W.; Lintz, H. E.; Sproles, E. A.
Predictions for the 21st century western United States climate include amplified fire regimes, earlier spring snowmelt and reduced snowpack. In the Pacific Northwest, burned area is projected to increase by as much as 300% by the end of this century. Continued declines in snowpack are also anticipated, especially at lower elevations. Previous research has established a link between declining snowpacks and wildfire. But what is the role of snow in the regeneration of vegetation after a fire? This investigation examines the relationship between post-fire vegetation and snowcover. We analyze the complex relationships between remotely sensed winter snow frequency and subsequent spring and summer vegetation biomass before and after large wildfires using a form of nonparametric multiplicative regression. We use snow cover and vegetation biomass data from the Moderate Resolution Imaging Spectroradiometer (MODIS). At each fire site, multiple physiographic predictor variables, (snow frequency, elevation, slope, aspect, vegetation type, and burn severity), are incorporated for the vegetation biomass response variable. For the Biscuit Fire (Klamath Mountains Ecoregion in SW Oregon), we see a negative correlation between winter snow frequency and subsequent spring EVI before the 2002 Biscuit Fire and a shift to a positive correlation after the fire during regeneration, while fires in other western ecoregions do not exhibit this shift. We also examine fire sites in the California Sierra Nevada and the Oregon Cascade Mountains. Snow cover frequency appears to be a valid predictor of post-fire biomass in climate regions where the summer dry period is relatively long. This research evaluates the relative importance of snowpack and other physiographic variables in post-fire vegetation regeneration across a latitudinal gradient of fire sites.
Miller, M. E.; Elliot, W. J.; Endsley, K. A.; Robichaud, P. R.; Billmire, M.
Post-fire flooding and erosion can pose a serious threat to life, property, and municipal water supplies. Increased peak flows and sediment delivery due to the loss of surface cover and fire-induced changes in soil properties are of great concern to both resource managers and the public. To respond to this threat, interdisciplinary Burned Area Emergency Response (BAER) Teams are formed to assess potential erosion and flood risks. These teams are under tight deadlines as remediation plans and treatments must be developed and implemented before the first major storms in order to be effective. One of the primary sources of information for making these decisions is a burn severity map derived from remote sensing data (typically Landsat) that reflects fire induced changes in vegetative cover and soil properties. Slope, soils, land cover, and climate are also important parameters that need to be considered when accessing risk. Many modeling tools and datasets have been developed to assist BAER teams, but process-based and spatially explicit empirical models are currently under-utilized compared to simpler, lumped models because they are both more difficult to set up and require spatially explicit inputs such as digital elevation models, soils, and land cover. We are working to facilitate the use of models by preparing spatial datasets within a web-based tool that rapidly modifies model inputs using burn severity maps derived from earth observation data. Automating the creation of model inputs facilitates the wider use of more accurate, process-based models for spatially explicit predictions of post-fire erosion and runoff.
Jeschke, Marc G; Chinkes, David L; Finnerty, Celeste C; Kulp, Gabriela; Suman, Oscar E; Norbury, William B; Branski, Ludwik K; Gauglitz, Gerd G; Mlcak, Ronald P; Herndon, David N
Objective To improve clinical outcome and to determine new treatment options, we studied the pathophysiologic response postburn in a large prospective, single center, clinical trial. Summary Background Data A severe burn injury leads to marked hypermetabolism and catabolism, which are associated with morbidity and mortality. The underlying pathophysiology and the correlations between humoral changes and organ function have not been well delineated. Methods Two hundred forty-two severely burned pediatric patients [>30% total body surface area (TBSA)], who received no anabolic drugs, were enrolled in this study. Demographics, clinical data, serum hormones, serum cytokine expression profile, organ function, hypermetabolism, muscle protein synthesis, incidence of wound infection sepsis, and body composition were obtained throughout acute hospital course. Results Average age was 8 ± 0.2 years, and average burn size was 56 ± 1% TBSA with 43 ± 1% third-degree TBSA. All patients were markedly hypermetabolic throughout acute hospital stay and had significant muscle protein loss as demonstrated by a negative muscle protein net balance (−0.05% ± 0.007 nmol/100 mL leg/min) and loss of lean body mass (LBM) (−4.1% ± 1.9%); P < 0.05. Patients lost 3% ± 1% of their bone mineral content (BMC) and 2 ± 1% of their bone mineral density (BMD). Serum proteome analysis demonstrated profound alterations immediately postburn, which remained abnormal throughout acute hospital stay; P < 0.05. Cardiac function was compromised immediately after burn and remained abnormal up to discharge; P < 0.05. Insulin resistance appeared during the first week postburn and persisted until discharge. Patients were hyperinflammatory with marked changes in IL-8, MCP-1, and IL-6, which were associated with 2.5 ± 0.2 infections and 17% sepsis. Conclusions In this large prospective clinical trial, we delineated the complexity of the postburn pathophysiologic response and conclude that the postburn
Robichaud, Peter; Elliot, William; Lewis, Sarah; Miller, Mary Ellen
The decision of where, when, and how to apply the most effective postfire erosion mitigation treatments requires land managers to assess the risk of damaging runoff and erosion events occurring after a fire. The Erosion Risk Management Tool (ERMiT) was developed to assist post fire assessment teams identify high erosion risk areas and effectiveness of various mitigation treatments to reduce that risk. ERMiT is a web-based application that uses the Water Erosion Prediction Project (WEPP) technology to estimate erosion, in probabilistic terms, on burned and recovering forest, range, and chaparral lands with and without the application of mitigation treatments. User inputs are processed by ERMiT to combine rain event variability with spatial and temporal variabilities of hillslope burn severity and soil properties which are then used as WEPP inputs. Since 2007, the model has been used in making hundreds of land management decisions in the US and elsewhere. We use eight published field study sites in the Western US to compare ERMiT predictions to observed hillslope erosion rates. Most sites experience only a few rainfall events that produced runoff and sediment except for a California site with a Mediterranean climate. When hillslope erosion occurred, significant correlations occurred between the observed hillslope erosion and those predicted by ERMiT. Significant correlation occurred for most mitigation treatments as well as the five recovery years. These model validation results suggest reasonable estimates of probabilistic post-fire hillslope sediment delivery when compared to observation.
Gouveia, C.; Dacamara, C. C.; Trigo, R. M.
A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI), with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.
Benavides-Solorio, J.; MacDonald, L. H.
Post-fire erosion and sediment yields are an important concern in the Colorado Front Range because past fires have adversely affected domestic water supplies, reservoir storage capacity, and coldwater fisheries habitat. The goal of this study was to evaluate the effects of season, fire severity, time since burning, and percent cover on erosion rates at the hillslope scale. Sediment production was monitored for 1-2 years from 48 sediment fences on six different wild and prescribed fires. Sediment production rates varied greatly between seasons, by time since burning, by fire severity, and between years. Summer rainstorms from June-September generally produced 10-50 times more sediment than snowmelt or mixed rain-and-snow events between October and May. The two oldest fires (1994 and 1998) had sediment production rates that were approximately 1-2 orders of magnitude lower than the four more recent fires. Fire severity was an important control on sediment production in the 2000 Bobcat wildfire and the November 1999 Old Flowers prescribed fire. In the case of the Bobcat fire, the high severity sites produced 50 times more sediment than the sites burned at moderate severity, and 500 times more sediment than the sites burned at low severity. There was little difference in sediment production rates between 2000 and 2001 for the Bobcat fire, while the other four more recent fires yielded very different amounts of sediment in 2000 and 2001. For two fires sediment production rates in summer 2000 were approximately seven times greater than in summer 2001, while the reverse was true for two other fires. The observed differences indicate that, at least for the first couple of years after burning, the amount and intensity of summer rainstorms can have a greater effect on sediment yields than time since burning. The decreases in sediment production with decreasing fire severity and increasing time since burning were strongly correlated with percent ground cover, as sites with
Wohlgemuth, P. M.
In fire-prone southern California chaparral environments, wildfire is a significant disturbance event. It incinerates vegetation, alters soil properties, and renders the landscape susceptible to the agents of erosion. Accelerated erosion can cause site degradation, can extirpate refugia populations of endangered species, and can harm human communities at the wildland/urban interface. The San Dimas Experimental Forest (SDEF) is a nearly 7000 ha research preserve located in the San Gabriel Mountains. Native vegetation in the SDEF consists primarily of mixed chaparral. Management treatments following a wildfire in 1960 involved the vegetation type-conversion of some native chaparral watersheds to a mixture of perennial grasses. In 1994, a study was initiated to quantify sediment fluxes through several small (1-3 ha) headwater catchments in the SDEF under both brush and grass vegetation. Several of these watersheds burned in a prescribed fire in May 2001. The remainder burned in a wildfire in September 2002. These burns provided a unique opportunity to quantify post-fire erosion on the same sites for which there were extensive pre- fire measurements. Hillslope erosion was sampled using sheet metal collector traps with a 30 cm aperture. Seventy-five traps were placed on unbounded plots scattered throughout each of four watersheds. Sediment yield was measured behind earthen dams in 17 small watersheds. A centrally located raingage recorded precipitation amounts and intensities. During this study period, the SDEF experienced both the wettest (2005) and driest (2007) years in its 74-year history. The values for the 15-minute maximum rainfall intensity show no relation to annual erosion (hillslope or small watershed) for either vegetation type before or after fire. Both hillslope erosion and small watershed sediment yield display remarkably similar patterns of post-fire erosion response: a one to two order of magnitude increase in first-year erosion followed by a relatively
Montorio Llovería, Raquel; Pérez-Cabello, Fernando; García-Martín, Alberto
Fire severity can be assessed by identifying and quantifying the fractional abundance of post-fire ground cover types, an approach with great capacity to predict ecosystem response. Focused on shrubland formations of Mediterranean-type ecosystems, three burned areas (Ibieca and Zuera wildfires and Peñaflor experimental fire) were sampled in the summers of 2006 and 2007. Two different ground measurements were made for each of the 356 plots: (i) 3-band high spatial resolution photography (HSRP) and (ii) the hemispherical-conical reflectance factor (HCRF) in the visible to near-infrared spectral range (VNIR, 400-900 nm). Stepwise multiple lineal regression (SMLR) models were fitted to spectral variables (HCRF, first derivative spectra or FDS, and four absorption indices) to estimate the fractional cover of seven post-fire ground cover types (vegetation and soil - unburned and charred components - and ash - char and ash, individually and as a combined category). Models were developed and validated at the Peñaflor site (training, n = 217; validation, n = 88) and applied to the samples from the Ibieca and Zuera sites (n = 51). The best results were observed for the abundance estimations of green vegetation (Radj.20.70-0.90), unburned soil (Radj.20.40-0.75), and the combination of ashes (Radj.20.65-0.80). In comparison of spectral data, FDS outperforms reflectance or absorption data because of its higher accuracy levels and, importantly, its greater capacity to yield generalizable models. Future efforts should be made to improve the estimation of intermediate severity levels and upscaling the developed models. In the context of fire severity assessment, our study demonstrates the potential of hyperspectral data to estimate in a quick and objective manner post-fire ground cover fractions and thus provide valuable information to guide management responses.
Benavides-Solorio, J.; MacDonald, L. H.
In recent years there has been a large increase in the number and size of wildfires in the mid-elevation zones of the Colorado Front Range. High-intensity rainstorms after these fires have increased erosion rates by several orders of magnitude and severely affected downstream aquatic resources. The objective of this study was to measure sediment production rates at the hillslope scale and determine the key controlling variables. To this end 48 sediment fences have been continuously monitored in three wildfires and three prescribed fires at elevations ranging from 1670 to 3050 m. The most intensively-studied area is the Bobcat fire, which burned 43 km2 in June 2000. Within this fire sediment production rates exceeded 10 Mg ha-1 yr-1 for areas burned at high severity. Prescribed fires produced substantially less sediment than the corresponding wildfires. Sediment production rates from sites burned at high severity were nearly 200 times higher than sites burned at moderate severity. Nearly all of the erosion occurred as a result of summer rainstorms rather than winter snowmelt. Sediment production rates per unit area were 2-3 times higher in swales or small drainages than from planar hillslopes. Data from the older fires indicate that sediment production rates remain elevated for sites burned at high severity for at least three years after burning. When the data from all fires were combined, 77% of the variability in sediment production rates could be explained by fire severity, percent bare soil, rainfall erosivity, soil water repellency, and soil texture. A simpler model using only percent cover and rainfall erosivity had a R2 of 0.62. Various models were tested against an independent data set from the Bobcat fire, and this showed that fire severity, percent bare soil, and rainfall erosivity could successfully predict post-fire erosion rates. The understanding and models developed in this project can help land managers predict the likely impacts from future
Micheletty, P. D.; Kinoshita, A. M.; Hogue, T. S.
Forest fires across the western U.S. have the potential to alter watershed processes for years after the event and have significant impact on snow accumulation and melt behavior, directly altering water yield. The paucity of literature on spatial and temporal variability in post-fire snow cover patterns is primarily due to the lack of available pre- and post-fire data. The current work evaluates the distribution of snow after large forest fires through the use of remotely sensed snow covered area (SCA). Accurately monitoring snow cover in mountainous terrain is complex, but recent remote sensing techniques have been shown to identify snow cover relatively well. Specifically, the Moderate Resolution Imaging Spectroradiometer (MODIS) snow covered area and grain size (MODSCAG) algorithm provides an accurate representation of snow cover at 500 m resolution through an improved multi-spectral mixing analysis. MODSCAG shows little sensitivity to vegetation cover types at the regional scale, and is therefore ideal for monitoring changes in spatial snow coverage after wildfire. MODSCAG is currently only available over the Sierra Nevada from 2000-2010. NASA MODIS SCA products, such as MOD10A1, however, are readily available from 2000-present over the entire U.S. Initial analysis includes investigation of relative changes in pre- and post-fire snow covered area over the 2007 Moonlight Fire in the northern Sierra Nevada (California), utilizing both MODSCAG and MOD10A1fractional SCA products. Preliminary results show statistically significant increases (at 95%) in post-fire basin averaged MODSCAG SCA, compared to a nearby unburned control basin and taking into account annual climate variability. Basin averaged snow cover during winter months show increases of 25% during the post-fire period with annual SCA averages increasing up to 10%. We also undertake a pixel by pixel analysis to study the effects of burn severity and slope aspect. Results show that regardless of these
MacDonald, L. H.; Rough, D. T.; Schaffrath, K.
Millions of dollars are spent each year to reduce runoff and erosion rates after high-severity wildfires, but there are relatively few data evaluating their effectiveness over longer time periods relative to natural recovery. In this study we summarize six years of hillslope erosion data from 18 untreated plots and five replicated post-fire rehabilitation treatments applied after the 2002 Hayman and Schoonover wildfires in the ponderosa pine zone in the central Colorado Front Range. The rate of recovery and effectiveness of these treatments are compared to the results from the 2000 Bobcat fire 130 km to the north (Wagenbrenner et al., 2006). On the Hayman fire straw mulching reduced hillslope-scale sediment yields by more than 90% in the first two summers after burning and by 77% in the third summer after burning. By the fourth summer the straw mulch had no significant effect on the amount of ground cover or sediment yields relative to the untreated controls. Aerial hydromulching had a similar effectiveness and longevity, but a ground-based hydromulch treatment was poorly formulated and did not significantly reduce sediment yields. Scarification and seeding did not increase the amount of surface cover or reduce sediment yields. The initial wet application of a polyacylamide appeared to reduce sediment yields, but subsequent applications did not have any significant effect. None of the treatments was effective for more than three summers after burning. The results confirm the fundamental importance of ground cover and are consistent with the mulching and seeding results from the Bobcat fire. The primary difference is the slower vegetative recovery rates for the coarser-textured soils in the Hayman and Schoonover fires, and this has caused post-fire sediment yields to remain elevated for six summers after burning as compared to a maximum of four summers for the Bobcat fire. Land managers must evaluate the duration of treatment effectiveness and post-fire erosion as
Wagenbrenner, J. W.; MacDonald, L. H.; Rough, D.
Post-fire rehabilitation treatments are commonly implemented after high-severity wildfires, but few data are available about the efficacy of these treatments. This study assessed post-fire erosion rates and the effectiveness of seeding, straw mulching, and contour felling in reducing erosion after a June 2000 wildfire northwest of Loveland, Colorado. Site characteristics and sediment yields were measured on 12 burned and untreated control plots and 22 burned and treated plots from 2000 to 2003. The size of the hillslope plots ranged from 0.015 to 0.86 ha.Sediment yields varied significantly by treatment and were most closely correlated with the amount of ground cover. On the control plots the mean sediment yield declined from 6-10 Mg ha-1 in the first two years after burning to 1.2 Mg ha-1 in 2002 and 0.7 Mg ha-1 in 2003. Natural regrowth caused the amount of ground cover on the control plots to increase progressively from 33% in fall 2000 to 88% in fall 2003. Seeding had no effect on either the amount of ground cover or sediment yields. Mulching reduced sediment yields by at least 95% relative to the control plots in 2001, 2002, and 2003, and the lower sediment yields are attributed to an immediate increase in the amount of ground cover in the mulched plots. The contour-felling treatments varied considerably in the quality of installation, and sediment storage capacities ranged from 7 to 32 m3 ha-1. The initial contour-felling treatment did not reduce sediment yields when subjected to a very large storm event, but sediment yields were significantly reduced by a contour-felling treatment installed after this large storm. The results indicate that contour felling may be able to store much of the sediment generated in an average year, but will not reduce sediment yields from larger storms.
Duffy, P.A.; Epting, J.; Graham, J.M.; Rupp, T.S.; McGuire, A.D.
Wildland fire is the dominant large-scale disturbance mechanism in the Alaskan boreal forest, and it strongly influences forest structure and function. In this research, patterns of burn severity in the Alaskan boreal forest are characterised using 24 fires. First, the relationship between burn severity and area burned is quantified using a linear regression. Second, the spatial correlation of burn severity as a function of topography is modelled using a variogram analysis. Finally, the relationship between vegetation type and spatial patterns of burn severity is quantified using linear models where variograms account for spatial correlation. These results show that: 1) average burn severity increases with the natural logarithm of the area of the wildfire, 2) burn severity is more variable in topographically complex landscapes than in flat landscapes, and 3) there is a significant relationship between burn severity and vegetation type in flat landscapes but not in topographically complex landscapes. These results strengthen the argument that differential flammability of vegetation exists in some boreal landscapes of Alaska. Additionally, these results suggest that through feedbacks between vegetation and burn severity, the distribution of forest vegetation through time is likely more stable in flat terrain than it is in areas with more complex topography. ?? IAWF 2007.
Malvar, Maruxa; Prats, Sérgio A.; Martins, Martinho A. S.; Gonzalez-Pelayo, Óscar; Keizer, Jacob J.
Wildfires have been reported worldwide as producing strong and sometimes extreme responses in runoff and soil erosion. However, in the case of North-Central Portugal, little research had been carried out regarding the hydrologic and erosive impacts of several land management activities in recently burnt areas (such as ground preparation, post-fire logging or post-fire mitigation treatments). This is the main objective of this research. Several pre- and post-fire ground preparation operations (down-slope rip-ploughed, contour ploughed and terracing), post-fire logging activities, and post-fire soil erosion mitigation treatments (forest residue mulches, polyacrylamide and hydromulch) were assessed from the first to the third post-fire years. Repeated rainfall simulation experiments (RSE's), micro-scale runoff plots and bounded sediment fences were installed immediately after the wildfire in twelve burnt slopes and monitored at weekly-basis intervals. The results for the first post-fire year showed comparable runoff coefficient (20-60%) but lower sediment losses (1.2-10 Mg ha-1) than prior studies in Portugal and worldwide, which corresponded well with the historic intensive land use in the area. Terracing sharply increased soil erosion (up to 30 Mg ha-1) at the micro-plots scale during the first year after a wildfire and terracing. However, sediment limited erosion was measured in all the pre-fire ploughed sites, probably due to the time elapsed since ploughing. Post-fire logging activities enhanced 5- to 10- fold the sediment losses, which was related to the disturbance of the soil surface cover. The mulches (forest residue or hydromulch) were highly effective reducing post-fire soil erosion in more than 80%. The increase on sediment losses of the recently terraced area and the measured sediment exhaustion at all the pre-fire ploughed sites as well as the increasing frequency of ploughing in the forest areas implies the need to consider ploughing as a hazardous
Sforza, Marcos; Andjelkov, Katarina; Zaccheddu, Renato
We report herein the case of a 42-year-old woman who presented to the Burns Unit with 81% of her body surface severely burned following sun bathing, after applying fig leaf tea as a tanning agent. The patient was hospitalized for 13 days in a Burns Intensive Care Unit, and was discharged for an ambulatory follow-up. The treatment of such burns does not differ from any conventional treatment for heat- induced second-degree burns. The physiopathology of the phytophotodermatitis induced by such homemade tanning solutions rich in psoralen is discussed in detail. PMID:23884685
Post-fire recovery of juniper-dominated ecosystems is dependent on the extent that ecological processes have been altered. Soil water repellency is a common condition in these ecosystems that may limit site recovery. In this study we examined the extent, severity, and ecohydrologic implications of p...
1. Most wildfires occur during summer in the northern hemisphere, the area burned annually is increasing, and fire effects during this season are least understood. Livestock grazing is a primary use of rangelands affected by wildfire, but post-fire grazing management is not well-supported with dat...
Rapid post-fire watershed assessment to identify potential trouble spots for erosion and flooding can potentially aid land managers and Burned Area Emergency Rehabilitation (BAER) teams in deploying mitigation and rehabilitation resources.
These decisions are inherently co...
MacDonald, Lee; Kampf, Stephanie; Brogan, Dan; Schmeer, Sarah; Nelson, Peter
Moderate and high severity wildfires can greatly reduce infiltration rates, leading to orders of magnitude increases in hillslope-scale runoff and erosion rates. These increases can cause dramatic downstream channel change, with post-fire deposition being most common, but this depends on the number, magnitude and timing of storm events. The objective of this study is to compare post-fire hillslope erosion rates and downstream channel change from two distinct rainfall events approximately one year after burning. The first was a set of relatively typical, higher-intensity convective storms in June-August 2013, and the second was a highly unusual, week-long ~270 mm rainstorm in September 2013. The study was conducted in two ~15 km2 watersheds that had two-thirds of their area burned at high or moderate severity by 2012 High Park Fire in northcentral Colorado, USA. Hillslope erosion was measured with sediment fences at 29 sites grouped into five clusters, with each cluster having an associated tipping bucket rain gage. Downstream channel change was monitored at approximately ten cross-sections in each of the two watersheds, Skin Gulch and Hill Gulch. Twelve summer storms produced an overall mean hillslope erosion of 6 Mg ha-1, with higher rainfall intensities at lower elevations and in Skin Gulch causing higher sediment yields. The higher sediment yields in Skin Gulch caused substantial downstream deposition of up to 0.8 m at most cross-sections. Generally lower rainfall in Hill Gulch resulted in less Horton overland flow and hence lower erosion rates and much less downstream deposition. The September storm had roughly twice as much rainfall as the summer thunderstorms, but there were much lower peak rainfall intensities and hillslope-scale sediment yields except where shallow bedrock induced saturation overland flow. The much longer duration of the September storm resulted in sustained high flows, and these flows plus the lower hillslope erosion caused most of the
Keeley, J.E.; Keeley, M.B.; Bond, W.J.
The contribution of resprouts and seedling recruitment to post-fire regeneration of the South African fynbos conifer Widdringtonia nodiflora was compared eight months after wildfires in 1990. Stems on all trees were killed by fire but resprouting success was > 90 % at all but one site. A demographic study of burned skeletons revealed that prior to these fires, nearly all plants were multi-stemmed (4 - 9 stems/plant) and multi-aged, indicating continuous sprout production between fires. All stems were killed by these 1990 fires and at most sites > 90 % of the stems were burned to ground level. All diameter stems were susceptible to such incineration as, at most sites, there was no difference in average diameter of stems burned to ground level and those left standing. Individual genets usually had all ramets incinerated to ground level or all ramets charred, but intact, suggesting certain micro-sites burned hotter, whereas other sites were somewhat protected. Although not true of the 1990 fires, there was evidence that occasionally Widdringtonia stems may survive fire. At one site, four of the 16 plants sampled had a burned stem twice as old as the oldest burned stem on the other 12 plants at the site, suggesting some stems had survived the previous fire (ca. 1970) and this conclusion was supported by fire-scars on these four stems that dated to ca. 1970. Based on the highly significant correlation between stem diameter and cone density left standing after the 1990 fries, we calculated that for most sites > 80 % of the initial cone crop was incinerated by fire. This is important because we observed a strong relationship between size of the canopy cone crop surviving fire and post-fire seedling recruitment. Under these conditions we hypothesize that sprouting confers a selective advantage to genets when fires cause heavy losses of seed. The infrequent occurrence of sprouting in the Cupressaceae suggests the hypothesis that resprouting is an apomorphic or derived trait
Moore, Paul; Lukenbach, Max; Waddington, James Michael
Wildfire is the largest disturbance affecting peatlands, where northern peat reserves are becoming increasingly vulnerable to wildfire as climate change is projected to enhance the length and severity of the fire season. However, little is known about the spatio-temporal variability of post-fire recovery in these ecosystems. High water table positions after wildfire are critical to limit atmospheric carbon losses and enable the re-establishment of keystone peatland mosses (i.e., Sphagnum). Post-fire recovery of the moss surface in Sphagnum-feathermoss peatlands, however, has been shown to be limited where moss type and burn severity interact to result in a water repellent surface. While in situ measurements of moss water repellency in peatlands has been shown to be greater for feathermoss in both a burned and unburned state in comparison to Sphagnum moss, it is difficult to separate effects of water content from species. Consequently, we carried out a drying experiment in the lab where we compared the water repellency of two dominant peatland moss species, Sphagnum and feathermoss, for several burn severity classes as well as for unburned samples. The results suggest that water repellency in moss is primarily controlled by water content, where a sharp threshold exists at gravimetric water contents (GWC) lower than ~3 g g-1. While GWC is shown to be a strong predictor of water repellency, the effect is enhanced by combustion. Based on field GWC, we show that there are significant differences in the frequency distribution of near-surface GWC between moss type and burn severity. The differences in the distributions of field GWC are related to characteristic moisture retention curves of unburned samples measured in the lab, as well as morphological differences between moss type.
Diaz, Eva C.; Herndon, David N.; Lee, Jinhyung; Porter, Craig; Cotter, Matthew; Suman, Oscar E.; Sidossis, Labros S.; Børsheim, Elisabet
Background Following a major burn, skeletal muscle protein synthesis rate increases, but is often insufficient to compensate for massively elevated muscle protein breakdown rates. Given the long-term nature of the pathophysiologic response to burn injury, we hypothesized that muscle protein synthesis rate would be chronically elevated in severely burned children. The objectives of this study were to characterize muscle protein synthesis rate of burned children over a period of 24 months post-injury, and identify predictors that influence this response. Study design 87 children with ≥40% total body surface area (TBSA) burn were included. Patients participated in stable isotope infusion studies at 1, 2 and ~ 4 weeks post-burn, and at 6, 12 and 24 months post-injury to determine skeletal muscle fractional synthesis rate. Generalized estimating equations with log link normal distribution were applied to account for clustering of patients and control for patient characteristics. Results Patients (8±6 years) had large (62, 51–72% TBSA) and deep (47±21% TBSA third degree) burns. Muscle fractional synthesis rate was elevated throughout the first 12 months post-burn compared to established values from healthy young adults. Muscle fractional synthesis rate was lower in boys, children >3 years old, and when burns were >80% TBSA. Conclusions Muscle protein synthesis is elevated for at least one year after injury, suggesting that greater muscle protein turnover is a component of the long-term pathophysiological response to burn trauma. Muscle protein synthesis is highly affected by gender, age and burn size in severely burned children. These findings may explain the divergence in net protein balance and lean body mass in different populations of burn victims. PMID:25807408
Glas, G J; Levi, M; Schultz, M J
Severe burn injury is associated with systemic coagulopathy. The changes in coagulation described in patients with severe burns resemble those found patients with sepsis or major trauma. Coagulopathy in patients with severe burns is characterized by procoagulant changes, and impaired fibrinolytic and natural anticoagulation systems. Both the timing of onset and the severity of hemostatic derangements are related to the severity of the burn. The exact pathophysiology and time course of coagulopathy are uncertain, but, at least in part, result from hemodilution and hypothermia. As the occurrence of coagulopathy in patients with severe burns is associated with increased comorbidity and mortality, coagulopathy could be seen as a potential therapeutic target. Clear guidelines for the treatment of coagulopathy in patients with severe burns are lacking, but supportive measures and targeted treatments have been proposed. Supportive measures are aimed at avoiding preventable triggers such as tissue hypoperfusion caused by shock, or hemodilution and hypothermia following the usually aggressive fluid resuscitation in these patients. Suggested targeted treatments that could benefit patients with severe burns include systemic treatment with anticoagulants, but sufficient randomized controlled trial evidence is lacking. PMID:26854881
Morita, Seiji; Higami, Shigeo; Yamagiwa, Takeshi; Iizuka, Shinichi; Nakagawa, Yoshihide; Yamamoto, Isotoshi; Inokuchi, Sadaki
In this study, we report the clinical characteristics of elderly Japanese patients with severe burns. We studied the clinical features of 76 adult patients with severe burns, 35 of whom (46.1%) were ≥65 years old. We evaluated the characteristics of patients with respect to each type of burn. In addition, we studied the rate of death and survival in the elderly and also between the elderly and non-elderly patients. The following parameters were either assessed or compared between the elderly and non-elderly: gender, average age, vital signs (Glasgow Coma Scale, systolic blood pressure, heart rate and respiratory rate) and PaO(2)/FiO(2) (P/F) ratio at admission, cause of burn and a history of physical or psychiatric disease. Further, we investigated whether the burn was caused by attempting suicide and determined the percent total body surface area (%TBSA), second- and third-degree burn area, burn index (BI), prognostic burn index (PBI), presence of tracheal burns, presence of alcohol intoxication and overdose poisoning, presence of tracheal intubation, outcome and cause of death. The male:female ratio of the elderly patients was 17:18 (average age, 78.1 (8.2) years). Burns were mostly caused by flame (26/35), followed by scalding (8/35). Ten patients had attempted suicide. The %TBSA, second-degree burn area, third-degree burn area, BI and PBI, respectively were 46.6% (26.7%), 15.3% (19.0%), 35.6% (26.0%), 41.1 (25.2) and 119.2 (25.9). Of the 35 patients, 23 died. The notable characteristics of the elderly patients who died were flame as the cause of the burns: high %TBSA, BI and PBI, and a high rate of tracheal intubation. Elderly patients constituted approximately 45% of our study population. Most burns were caused by flames. The incidence of accidental bathtub-related burns was higher and that of suicide attempts was lower in the elderly patients, as compared with the non-elderly patients. Severe burns were fatal for elderly patients. Therefore, elderly
Gershberg, Anna; Ne'eman, Gidi; Ben-Shlomo, Rachel
To study the effects of wildfire on population genetics of a wind pollinated and wind dispersed tree, we have analyzed the genetic structure of a post-fire, naturally regenerating seedling population of Pinus halepensis Miller, on Mt. Carmel, Israel. We tested the existence of spatial genetic structure, which is expected due to the special spatial demographic structure of the post-fire seedling and sapling populations of this species. Explicitly, we asked whether or not seedlings that germinated under large, burned, dead pine trees are also their offspring. The results revealed that the post-fire seedling population is polymorphic, diverse, and reflects the pre-fire random mating system. In contrast to our prediction, we found no division of the post-fire seedling population to distinct sub-populations. Furthermore, as a result of post-fire seed dispersal to longer range than the average pre-fire inter-tree distance, seedlings found under individual burned trees were not necessarily their sole offspring. Although the population as a whole showed a Hardy-Weinberg equilibrium, significant excess of heterozygotes was found within each tallest seedlings group growing under single, large, burned pine trees. Our finding indicates the possible existence of intense natural selection for the most vigorous heterozygous genotypes that are best adapted to the special post-fire regeneration niche, which is the thick ash bed under large, dead, pine trees. PMID:27200024
Gershberg, Anna; Ne'eman, Gidi; Ben-Shlomo, Rachel
To study the effects of wildfire on population genetics of a wind pollinated and wind dispersed tree, we have analyzed the genetic structure of a post-fire, naturally regenerating seedling population of Pinus halepensis Miller, on Mt. Carmel, Israel. We tested the existence of spatial genetic structure, which is expected due to the special spatial demographic structure of the post-fire seedling and sapling populations of this species. Explicitly, we asked whether or not seedlings that germinated under large, burned, dead pine trees are also their offspring. The results revealed that the post-fire seedling population is polymorphic, diverse, and reflects the pre-fire random mating system. In contrast to our prediction, we found no division of the post-fire seedling population to distinct sub-populations. Furthermore, as a result of post-fire seed dispersal to longer range than the average pre-fire inter-tree distance, seedlings found under individual burned trees were not necessarily their sole offspring. Although the population as a whole showed a Hardy-Weinberg equilibrium, significant excess of heterozygotes was found within each tallest seedlings group growing under single, large, burned pine trees. Our finding indicates the possible existence of intense natural selection for the most vigorous heterozygous genotypes that are best adapted to the special post-fire regeneration niche, which is the thick ash bed under large, dead, pine trees. PMID:27200024
Nguyen, John Quan; Crouzet, Christian; Mai, Tuan; Riola, Kathleen; Uchitel, Daniel; Liaw, Lih-Huei; Bernal, Nicole; Ponticorvo, Adrien; Choi, Bernard; Durkin, Anthony J.
Frequent monitoring of early-stage burns is necessary for deciding optimal treatment and management. Both superficial and full thickness burns are relatively easy to diagnose based on clinical observation. In between these two extremes are superficial-partial thickness and deep-partial thickness burns. These burns, while visually similar, differ dramatically in terms of clinical treatment and are known to progress in severity over time. The objective of this study was to determine the potential of spatial frequency domain imaging (SFDI) for noninvasively mapping quantitative changes in chromophore and optical properties that may be an indicative of burn wound severity. A controlled protocol of graded burn severity was developed and applied to 17 rats. SFDI data was acquired at multiple near-infrared wavelengths over a course of 3 h. Burn severity was verified using hematoxylin and eosin histology. From this study, we found that changes in water concentration (edema), deoxygenated hemoglobin concentration, and optical scattering (tissue denaturation) to be statistically significant at differentiating superficial partial-thickness burns from deep-partial thickness burns.
Canu, A.; Arca, B.; Ventura, A.; Ghiglieri, G.; Pittalis, D.; Deroma, M.
Despite the large number of works on fire effects on soil and post-fire recovery in Mediterranean areas, several aspects need to be established. The study area is located in north-western Sardinia. The climate is sub-arid Mediterranean, with a mean annual temperature of about 16.8 °C and mean annual precipitation ranging from 600 mm to 700 mm, with an autumn maximum. The area is mainly covered by the typical shrubland Mediterranean vegetation. The object of this study is: i) to compare burned and unburned soil in order to evaluate the effect of fire on physical and chemical soil properties; ii) to analyse the vegetation recovery of the main Mediterranean maquis species. The analysis was carried out in a human caused fire occurred in North-West Sardinia (Italy) immediately after fire in 2006, and during the 2007 and 2008 summer seasons. Several pedological samples were collected from various depths (0-5, 5-15 and 15-25 cm) and under the canopy of different species (Chamaerops humilis L., Pistacia lentiscus L. and Calycotome spinosa L.), both in burned and in unburned plots. The soil organic matter content, total and available element concentrations, and soil texture were then determined in laboratory. Different statistical parameters were calculated to describe the relationships between soil properties and species composition comparing burned and unburned plots.
Hart, David W.; Wolf, Steven E.; Chinkes, David L.; Gore, Dennis C.; Mlcak, Ronald P.; Beauford, Robert B.; Obeng, Michael K.; Lal, Sophia; Gold, Warren F.; Wolfe, Robert R.; Herndon, David N.
Objective To determine which patient factors affect the degree of catabolism after severe burn. Summary Background Data Catabolism is associated with severe burn and leads to erosion of lean mass, impaired wound healing, and delayed rehabilitation. Methods From 1996 to 1999, 151 stable-isotope protein kinetic studies were performed in 102 pediatric and 21 adult subjects burned over 20–99.5% of their total body surface area (TBSA). Patient demographics, burn characteristics, and hospital course variables were correlated with the net balance of skeletal muscle protein synthesis and breakdown across the leg. Data were analyzed sequentially and cumulatively through univariate and cross-sectional multiple regression. Results Increasing age, weight, and delay in definitive surgical treatment predict increased catabolism (P < .05). Body surface area burned increased catabolism until 40% TBSA was reached; catabolism did not consistently increase thereafter. Resting energy expenditure and sepsis were also strong predictors of net protein catabolism. Among factors that did not significantly correlate were burn type, pneumonia, wound contamination, and time after burn. From these results, the authors also infer that gross muscle mass correlates independently with protein wasting after burn. Conclusions Heavier, more muscular subjects, and subjects whose definitive surgical treatment is delayed are at the greatest risk for excess catabolism after burn. Sepsis and excessive hypermetabolism are also associated with protein catabolism. PMID:10998644
Staley, D. M.; Kean, J. W.; Smoczyk, G. M.; Negri, J. A.
Wildfire can have profound effects on the hydrologic response of a watershed, and debris-flow activity is among the most destructive consequences of these effects. The continued high likelihood of catastrophic wildfires in the western U. S. and the encroachment of development into fire-prone areas have created the need to develop tools to identify and quantify the potential hazards posed by debris flows generated from burned watersheds. These tools are critically needed by Federal, State, and local agencies to mitigate the impacts of debris flows on people, their property, infrastructure and natural resources. Applied research at the U.S. Geological Survey (USGS) Landslide Hazards Program is focused on providing timely, science-based assessments of post-fire debris-flow hazard. Formerly, post-fire debris-flow hazard assessments were disseminated by means of the USGS Open-File Report publication series, which included poster-sized maps that predicted the probability, volume, and combined hazard for given watersheds. Feedback from collaborators suggested that 1) the reports were not sufficiently timely for immediate post-fire use, 2) the static maps were difficult to use for site-specific assessments, and 3) individual assessments were often cost-prohibitive. Beginning in January 2014, the USGS has transitioned to a web-based method for disseminating post-fire debris-flow hazard assessments. This new platform addresses the primary concerns of our stakeholders in three ways. First, the turnaround time has been reduced from 1-2 months for a map and written report, to 3-4 days for a web-based map assessment. This allows response teams to incorporate the assessment results into their reports, which are urgently needed immediately after fires. Second, the new website is interactive and accompanied by downloadable geospatial data of predictions for several storm scenarios. These features permit casual (local residents) and power-users (GIS experts) to evaluate site
Jain, Theresa B.; Pilliod, David S.; Graham, Russell T.; Lentile, Leigh B.; Sandquist, Jonathan E.
Many scientists and managers have an interest in describing the environment following a fire to understand the effects on soil productivity, vegetation growth, and wildlife habitat, but little research has focused on the scientific rationale for classifying the post-fire environment. We developed an empirically-grounded soil post-fire index (PFI) based on available science and ecological thresholds. Using over 50 literature sources, we identified a minimum of five broad categories of post-fire outcomes: (a) unburned, (b) abundant surface organic matter ( > 85% surface organic matter), (c) moderate amount of surface organic matter ( ≥ 40 through 85%), (d) small amounts of surface organic matter ( < 40%), and (e) absence of surface organic matter (no organic matter left). We then subdivided each broad category on the basis of post-fire mineral soil colors providing a more fine-tuned post-fire soil index. We related each PFI category to characteristics such as soil temperature and duration of heating during fire, and physical, chemical, and biological responses. Classifying or describing post-fire soil conditions consistently will improve interpretations of fire effects research and facilitate communication of potential responses or outcomes (e.g., erosion potential) from fires of varying severities.
Oliva, Patricia; De Santis, Angela
This paper presents the first results of Fire Effects Modelling and Mapping (FEMM) project carried out in the framemark of the Changing Earth Science Network. The objective of this study is to test the performance of the inversion of Radiative Transfer Models (RTMs) in ENVISA T-MERIS Full Resolution data to estimate burn severity levels in terms of Composite Burn Index (CBI) levels. Nevertheless, as the RTM model was calibrated in Landsat-TM images, evaluation of its performance in MERIS imagery was needed. We tested the performance of the RTM model in several study sites located in two large fires occurred in Spain during 2009 fire season. The results were validated by comparison with burn severity maps computed from Landsat-TM imagery. The results obtained showed values of the coefficient of determination of 0.92 and 0.95 thus, the estimation of burn severity was accurate and consistent, in spite of the different spatial and spectral resolutions.
Patel, Pavankumar; Sallam, Hanaa S.; Ali, Arham; Chandalia, Manisha; Suman, Oscar; Finnerty, Celeste C.; Herndon, David N.
Abstract Background: Children with severe cutaneous burn injury show persistent metabolic abnormalities, including inflammation and insulin resistance. Such abnormalities could potentially increase their future risk for developing type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). This could be related to changes in body composition and fat distribution. Methods: We studied body composition, fat distribution, and inflammatory cytokines changes in children with severe burn injury up to 6 months from discharge. Sixty-two boys and 35 girls (burn ≥30% of total body surface area) were included. Results: We found a decrease in total body fat and subcutaneous peripheral fat at 6 months (6% and 2%, respectively; P<0.05 each). An inverse correlation between the decrease in peripheral fat content at 6 months and the extent of burn injury (r=−041, P=0.02) was also observed. In addition, there was a 12% increase in serum tumor necrosis factor-α (TNF-α) (P=0.01 vs. discharge) and 9% decrease in serum interleukin-10 (IL-10) (P<0.0001 vs. discharge) over 6 months after burn. Conclusion: Severe burn injury in children is associated with changes in body fat content and distribution up to 6 months from hospital discharge. These changes, accompanied by persisting systemic inflammation, could possibly mediate the observed persistence of insulin resistance, predisposing burn patients to the development of T2DM and CVD. PMID:25211297
Hyde, K.; Woods, S.
High intensity rainfall may trigger gully rejuvenation on hillslopes recently disturbed by wildfire, leading to debris-laden flows which generally contribute the majority of sediment transported in post-fire erosion events. We investigated the extent to which the occurrence of gully rejuvenation can be predicted based upon burn severity, rainfall data and basin morphometric variables. Field surveys were conducted at six Northern Rockies sites to identify occurrence of gully rejuvenation in first order catchments and to map and characterize the location of gully heads. NEXRAD and rain gage data analysis coupled with field observations characterized rainfall intensity and extent. Building on previous work we quantified burn severity using the Vegetation Disturbance Index (VDI), a continuous metric based upon Burned Area Reflectance Classification (BARC) maps derived from satellite imagery using the dNBR algorithm. GIS analysis combined the VDI with morphometric factors expected to influence hillslope stability. Gully heads marked abrupt transition in channel form. Above gully heads, channels were shallow and U-shaped with gentle transition to the hillslope and fine root hairs intact. Angular edges marked deep gully head incisions which down-cut channel floors from 0.2-0.3 to 1.0 meter or more. Any remaining roots were coarse and the hillslope transition was sharp. Gully heads were located at variable distances below the master rill head of the catchment hollow. Distances were obviously greater where live canopy remained upslope. Gully head morphology strongly suggests flow force transition and exceedance of an erosion process threshold. The variable distance of the gully head below the hollow suggest upslope controls influencing initiation point, possibly degree and spatial pattern of burn severity. Binary logistic regression revealed stronger correlation between gully rejuvenation and VDI than morphometric variables. The statistical strength using the continuous
Robichaud, P.R.; Lewis, S.A.; Laes, D.Y.M.; Hudak, A.T.; Kokaly, R.F.; Zamudio, J.A.
Burn severity is mapped after wildfires to evaluate immediate and long-term fire effects on the landscape. Remotely sensed hyperspectral imagery has the potential to provide important information about fine-scale ground cover components that are indicative of burn severity after large wildland fires. Airborne hyperspectral imagery and ground data were collected after the 2002 Hayman Fire in Colorado to assess the application of high resolution imagery for burn severity mapping and to compare it to standard burn severity mapping methods. Mixture Tuned Matched Filtering (MTMF), a partial spectral unmixing algorithm, was used to identify the spectral abundance of ash, soil, and scorched and green vegetation in the burned area. The overall performance of the MTMF for predicting the ground cover components was satisfactory (r2 = 0.21 to 0.48) based on a comparison to fractional ash, soil, and vegetation cover measured on ground validation plots. The relationship between Landsat-derived differenced Normalized Burn Ratio (dNBR) values and the ground data was also evaluated (r2 = 0.20 to 0.58) and found to be comparable to the MTMF. However, the quantitative information provided by the fine-scale hyperspectral imagery makes it possible to more accurately assess the effects of the fire on the soil surface by identifying discrete ground cover characteristics. These surface effects, especially soil and ash cover and the lack of any remaining vegetative cover, directly relate to potential postfire watershed response processes. ?? 2006 Elsevier Inc. All rights reserved.
Wells, A.; Morgan, P.; Smith, A. M.; Hudak, A. T.; Hicke, J. A.
data 1984-2007(n = 16, Spearman's Rank Correlation r = -0.12 and p = 0.64). Total tree seedling density 12 years post-fire was lower in large patches (Kruskal Wallis ANOVA p = 0.005) with fewer trees at 40 m and 80 m than at 10 m from unburned edges in severely burned patches (respectively, Wilcoxon Rank Sum Test p = 0.03 and 0.01). Understory species richness and diversity did not differ with distance from unburned edge, likely because many species resprout or establish from existing seed banks. Understanding how proportion of area burned severely is changing over multiple decades will help ecologists and land managers better understand where, when, and why fires burn severely and their past, present, and future consequences.
Benavides-Solorio, Juan; MacDonald, Lee H.
An Erratum has been published for this article in Hydrological Processes 16(5) 2002, 1131-1133.Wildfires in the Colorado Front Range can trigger dramatic increases in runoff and erosion. A better understanding of the causes of these increases is needed to predict the effects of future wildfires, estimate runoff and erosion risks from prescribed fires, and design effective post-fire rehabilitation treatments. The objective of this project was to determine whether runoff and sediment yields were significantly related to the site variables of burn severity, percent cover, soil water repellency, soil moisture, time since burning, and slope. To eliminate the variability due to natural rainfall events, we applied an artificial storm of approximately 80 mm h-1 on 26 1 m2 plots in the summer and fall of 2000. The plots were distributed among a June 2000 wildfire, a November 1999 prescribed fire, and a July 1994 wildfire.For 23 of the 26 plots the ratio of runoff to rainfall exceeded 50%. Nearly all sites exhibited strong natural or fire-induced water repellency, so the runoff ratios were only 15-30% larger for the high-severity plots in the two more recent fires than for the unburned or low-severity plots. The two high-severity plots in the 1994 wildfire had very low runoff ratios, and this probably was due to the high soil moisture conditions at the time of the simulated rainfall and the resulting reduction in the natural water repellency. Sediment yields from the high-severity sites in the two more recent fires were 10-26 times greater than the unburned and low-severity plots. The plots burned at high severity in 1994 yielded only slightly more sediment than the unburned plots. Percent ground cover explained 81% of the variability in sediment yields, and the sediment yields from the plots in the 1994 wildfire are consistent with the observed recovery in percent ground cover.
Snags are an important component of forest ecosystems because of their utility in forest-nutrient cycling and provision of critical wildlife habitat, as well as associated fuel management concerns relating to coarse woody debris (CWD). Knowledge of snag and CWD trajectories are needed for land managers to plan for long-term ecosystem change in post-fire regimes. This need will likely be exacerbated by increasingly warm and dry climatic conditions projected for the U.S. Southwest. One of the best prospects for studying fire-induced landscape change beyond the plot scale, but still at a resolution sufficient to resolve individual snags, is to utilize the available aerial photography record. Previous field-based studies of snag and CWD loads in the Southwest have relied on regional chronosequences to judge the recovery dynamic of ponderosa pine (Pinus ponderosa) burns. This previous research has been spatially and temporally restricted because of field survey extent limitations and uncertainty associated with the chronosequence approach (i.e., space-for-time substitution), which does not consider differences between specific site conditions and histories. This study develops highly automated methods for remotely quantifying and characterizing the spatial and temporal distribution of large snags associated with severe forest fires from very high resolution (VHR) landscape imagery I obtained from scans of aerial photos. Associated algorithms utilize the sharp edges, shape, shadow, and contrast characteristics of snags to enable feature recognition. Additionally, using snag shadow length, image acquisition time, and location information, heights were estimated for each identified snag. Furthermore, a novel solution was developed for extracting individual snags from areas of high snag density by overlaying parallel lines in the direction of the snag shadows and extracting local maxima lines contained by each snag polygon. Field survey data coincident to imagery coverage
Francos, Marcos; Pereira, Paulo; Alcañiz, Meritxell; Úbeda, Xavi
Post-fire management after severe wildfires has impact on soil properties. In Mediterranean environments management of fire affected areas is a common practice. This intervention may change soil chemical properties of the soil such as major cations. The aim of this work is to study the impact of different types of forest management in soil extractable calcium, magnesium, sodium and potassium after a severe wildfire. The study area is located in Ódena (Catalonia, Spain). The wildfire occurred at July 27th of 2015 and burned 1235 ha. After the fire an experimental plot was designed 9 plots with 2x2 meters (4 square meters). The different managements were: a) clear-cuted area and wood removed, b) no treatment); and c) clear-cutted. The results of the first sampling showed significant differences among all treatments in extractable calcium, sodium and potassium. The amount of these extractable elements was high in clear-cutted treatment in comparison to the others. No differences were identified in extractable magnesium. Overall, in the immediate period after the fire, burned area management, changed the studied soil properties. We are currently studying the evolution of this soil properties in these plots with the time
Pereg, Lily; Mataix-Solera, Jorge; McMillan, Mary; García-Orenes, Fuensanta
Microbial diversity and function in soils are increasingly assessed by the application of molecular methods such as sequencing and PCR technology. We applied these techniques to study microbial recovery in post-fire forest soils. The recovery of forest ecosystems following severe fire is influenced by post-fire management. The removal of burnt tree stumps (salvage logging) is a common practice in Spain following fire. In some cases, the use of heavy machinery in addition to the vulnerability of soils to erosion and degradation make this management potentially damaging to soil, and therefore to the ecosystem. We hypothesized that tree removal slows down the recovery of soil biological communities including microbial and plant communities and contributes to soil degradation in the burnt affected area. The study area is located in "Sierra de Mariola Natural Park" in Alcoi, Alicante (E Spain). A big forest fire (>500 has) occurred in July 2012. The forest is composed mainly of Pinus halepensis trees with an understory of typical Mediterranean shrubs species such as Quercus coccifera, Rosmarinus officinalis, Thymus vulgaris, Brachypodium retusum, etc. Soil is classified as a Typic Xerorthent (Soil Survey Staff, 2014) developed over marls. In February 2013, salvage logging (SL) treatment, with a complete extraction of the burned wood using heavy machinery, was applied to a part of the affected forest. Plots for monitoring the effects of SL were installed in this area and in a similar nearby control (C) area, where no SL treatment was done. The recovery of soil bacterial and fungal communities post-fire with and without tree removal was analysed by using Next-Generation sequencing and the abundance of functional genes, related to nitrogen cycling, in the soil was estimated using quantitative PCR (qPCR). We will present the methods used and the results of our study in this PICO presentation.
Shinneman, Douglas; McIlroy, Susan
Sagebrush steppe of North America is considered highly imperilled, in part owing to increased fire frequency. Sagebrush ecosystems support numerous species, and it is important to understand those factors that affect rates of post-fire sagebrush recovery. We explored recovery of Wyoming big sagebrush (Artemisia tridentata ssp.wyomingensis) and basin big sagebrush (A. tridentata ssp. tridentata) communities following fire in the northern Columbia Basin (Washington, USA). We sampled plots across 16 fires that burned in big sagebrush communities from 5 to 28 years ago, and also sampled nearby unburned locations. Mixed-effects models demonstrated that density of large–mature big sagebrush plants and percentage cover of big sagebrush were higher with time since fire and in plots with more precipitation during the winter immediately following fire, but were lower when precipitation the next winter was higher than average, especially on soils with higher available water supply, and with greater post-fire mortality of mature big sagebrush plants. Bunchgrass cover 5 to 28 years after fire was predicted to be lower with higher cover of both shrubs and non-native herbaceous species, and only slightly higher with time. Post-fire recovery of big sagebrush in the northern Columbia Basin is a slow process that may require several decades on average, but faster recovery rates may occur under specific site and climate conditions.
Eidenshink, Jeffery C.; Schwind, Brian; Brewer, Ken; Zhu, Zhu-Liang; Quayle, Brad; Howard, Stephen M.
Jeff Eidenshink, Brian Schwind, Ken Brewer, Zhi-Liang Zhu, Brad Quayle, and Elected officials and leaders of environmental agencies need information about the effects of large wildfires in order to set policy and make management decisions. Recently, the Wildland Fire Leadership Council (WFLC), which implements and coordinates the National Fire Plan (NFP) and Federal Wildland Fire Management Policies (National Fire Plan 2004), adopted a strategy to monitor the effectiveness of the National Fire Plan and the Healthy Forests Restoration Act (HFRA). One component of this strategy is to assess the environmental impacts of large wildland fires and identify the trends of burn severity on all lands across the United States. To that end, WFLC has sponsored a six-year project, Monitoring Trends in Burn Severity (MTBS), which requires the U.S. Department of Agriculture Forest Service (USDA-FS) and the U.S. Geological Survey (USGS) to map and assess the burn severity for all large current and historical fires. Using Landsat data and the differenced Normalized Burn Ratio (dNBR) algorithm, the USGS Center for Earth Resources Observation and Science (EROS) and USDA-FS Remote Sensing Applications Center will map burn severity of all fires since 1984 greater than 202 ha (500ac) in the east, and 404 ha (1,000 ac) in the west. The number of historical fires from this period combined with current fires occurring during the course of the project will exceed 9,000. The MTBS project will generate burn severity data, maps, and reports, which will be available for use at local, state, and national levels to evaluate trends in burn severity and help develop and assess the effectiveness of land management decisions. Additionally, the information developed will provide a baseline from which to monitor the recovery and health of fire-affected landscapes over time. Spatial and tabular data quantifying burn severity will augment existing information used to estimate risk associated with a range
Moody, J.A.; Martin, D.A.; Haire, S.L.; Kinner, D.A.
Extreme floods often follow wildfire in mountainous watersheds. However, a quantitative relation between the runoff response and burn severity at the watershed scale has not been established. Runoff response was measured as the runoff coefficient C, which is equal to the peak discharge per unit drainage area divided by the average maximum 30 min rainfall intensity during each rain storm. The magnitude of the bum severity was expressed as the change in the normalized burn ratio. A new burn severity variable, hydraulic functional connectivity ?? was developed and incorporates both the magnitude of the burn severity and the spatial sequence of the bum severity along hillslope flow paths. The runoff response and the burn severity were measured in seven subwatersheds (0.24 to 0.85 km2) in the upper part of Rendija Canyon burned by the 2000 Cerro Grande Fire Dear Los Alamos, New Mexico, USA. A rainfall-discharge relation was determined for four of the subwatersheds with nearly the same bum severity. The peak discharge per unit drainage area Qupeak was a linear function of the maximum 30 min rainfall intensity I30. This function predicted a rainfall intensity threshold of 8.5 mm h-1 below which no runoff was generated. The runoff coefficient C = Qupeak/I30 was a linear function of the mean hydraulic functional connectivity of the subwatersheds. Moreover, the variability of the mean hydraulic functional connectivity was related to the variability of the mean runoff coefficient, and this relation provides physical insight into why the runoff response from the same subwatershed can vary for different rainstorms with the same rainfall intensity. Published in 2007 by John Wiley & Sons, Ltd.
Maranon-Jimenez, Sara; Castro, Jorge; Querejeta, José Ignacio; Fernandez-Ondono, Emilia; Allen, Craig D.
Extensive research has focused on comparing the impacts of post-fire salvage logging versus those of less aggressive management practices on forest regeneration. However, few studies have addressed the effects of different burnt-wood management options on seedling/sapling performance, or the ecophysiological mechanisms underlying differences among treatments. In this study, we experimentally assess the effects of post-fire management of the burnt wood on the growth and performance of naturally regenerating pine seedlings (Pinus pinaster). Three post-fire management treatments varying in degree of intervention were implemented seven months after a high-severity wildfire burned Mediterranean pine forests in the Sierra Nevada, southeast Spain: (a) “No Intervention” (NI, all burnt trees left standing); (b) “Partial Cut plus Lopping” (PCL, felling most of the burnt trees, cutting off branches, and leaving all the biomass on site without mastication); and (c) “Salvage Logging” (SL, felling the burnt trees, piling up the logs and masticating the fine woody debris). Three years after the fire, the growth, foliar nutrient concentrations, and leaf carbon, nitrogen and oxygen isotopic composition (δ13C, δ18O and δ15N) of naturally regenerating seedlings were measured in all the treatments. Pine seedlings showed greatest vigor and size in the PCL treatment, whereas growth was poorest in SL. The nutrient concentrations were similar among treatments, although greater growth in the two treatments with residual wood present indicated higher plant uptake. Seedlings in the SL treatment showed high leaf δ13C and δ18O values indicating severe water stress, in contrast to significantly alleviated water stress indications in the PCL treatment. Seedling growth and physiological performance in NI was intermediate between that of PCL and SL. After six growing seasons, P. pinaster saplings in PCL showed greater growth and cone production than SL saplings. In summary
Williams, Felicia N; Herndon, David N; Suman, Oscar E; Lee, Jong O; Norbury, William B; Branski, Ludwik K; Mlcak, Ronald P; Jeschke, Marc G
Objective Cardiac stress, mediated by increased catecholamines, is the hallmark of severe burn injury typified by marked tachycardia, increased myocardial oxygen consumption, and increased cardiac output. It remains one of the main determinants of survival in large burns. It is currently unknown for how long cardiac stress persists after a severe injury. Therefore, the aim of this study was to determine the extent and duration of cardiac stress after a severe burn. To determine persistence of cardiac alteration we determined cardiac parameters of all surviving patients with burns ≥ 40% total body surface area (TBSA) from 1998 to 2008. Methods One-hundred ninety-four patients were included in this study. Heart Rate (HR), mean arterial pressure (MAP), cardiac output (CO), stroke volume (SV), cardiac index (CI), and ejection fractions (EF) were measured at regular intervals from admission up to two years after injury. Rate pressure product (RPP) was calculated as a correlate of myocardial oxygen consumption. All values were compared to normal non-burned children to validate our findings. Statistical analysis was performed using log transformed ANOVA with Bonferroni correction, and Student’s t-test where applicable. Results Heart rate, cardiac output, cardiac index and RPP remained significantly elevated in burned children for up to two years when compared to normal ranges (p<0.05) indicating vastly increased cardiac stress. Ejection fraction was within normal limits for two years. Conclusions Cardiac stress persists for at least 2 years post burn and we suggest that attenuation of these detrimental responses may improve long-term morbidity. PMID:21228708
Burke, M P; Hogue, T S; Kinoshita, A M; Barco, J; Wessel, C; Stein, E D
Post-fire runoff has the potential to be a large source of contaminants to downstream areas. However, the magnitude of this effect in urban fringe watersheds adjacent to large sources of airborne contaminants is not well documented. The current study investigates the impacts of wildfire on stormwater contaminant loading from the upper Arroyo Seco watershed, burned in 2009. This watershed is adjacent to the Greater Los Angeles, CA, USA area and has not burned in over 60 years. Consequently, it acts as a sink for regional urban pollutants and presents an opportunity to study the impacts of wildfire. Pre- and post-fire storm samples were collected and analyzed for basic cations, trace metals, and total suspended solids. The loss of vegetation and changes in soil properties from the fire greatly increased the magnitude of storm runoff, resulting in sediment-laden floods carrying high concentrations of particulate-bound constituents. Post-fire concentrations and loads were up to three orders of magnitude greater than pre-fire values for many trace metals, including lead and cadmium. A shift was also observed in the timing of chemical delivery, where maximum suspended sediment, trace metal, and cation concentrations coincided with, rather than preceded, peak discharge in the post-fire runoff, amplifying the fire's impacts on mass loading. The results emphasize the importance of sediment delivery as a primary mechanism for post-fire contaminant transport and suggest that traditional management practices that focus on treating only the early portion of storm runoff may be less effective following wildfire. We also advocate that watersheds impacted by regional urban pollutants have the potential to pose significant risk for downstream communities and ecosystems after fire. PMID:23912423
Parise, M.; Cannon, S. H.
proceedings. The database derives from critical analysis of the existing literature, integrated by case studies directly studied by the authors. Studies on recently burned areas in the Mediterranean basin are most frequently carried out on small experimental plots, often with simulated rainfall A problem of scale therefore exists when trying to extrapolate the erosion rates (also reported as sediment yields or as sediment losses) from these studies to a watershed scale. Very few articles, on the other hand, were found that document the watershed-scale response of basins to rainfall-induced erosion and debris flows following wildfires. The few reported cases of debris flows in the Mediterranean Basin describe erosion of sediment from the hillslopes and the channels (sometimes down to bedrock), and, for a limited number of sites, failure of discrete landslides. This information indicates that debris-flow generation from recently burned areas in the Mediterranean basin appears to occur primarily through sediment bulking processes. Nevertheless, the database so far compiled shows a distribution of post-fire erosion and debris flows in the western Mediterranean basin (Spain, essentially, but also Portugal), followed by the eastern Mediterranean area (Israel), and then by France, Italy and Greece. Even though still in a preliminary version, that needs to be integrated and updated from further sources, our data compilation allows for the unique opportunity to examine issues related to the generation of post-wildfire debris flows across a variety of environments and under a variety of conditions, and to move from a qualitative conception of the controls on post-fire debris-flow generation to the definition of specific conditions that result in their occurrence. Future activities of the project will include: i) updating and integration of the preliminary version of the database; ii) development of models that can be used to identify the probability of debris-flow occurrence and the
Sawada, Y; Momma, S; Takamizawa, A; Nishida, S
We describe a patient with 50 per cent, third degree flame burns who had a history of paint thinner inhalation for over 10 years. Moreover, chlorpromazine had been administered for the treatment of insomnia caused by chronic thinner intoxication. He developed oliguric acute renal failure soon after the burn injury, although adequate resuscitation therapy was given, and survived following frequent haemodialysis. Although survival from acute renal failure after severe burns is rare, once the diagnosis of acute renal failure has been made, haemodialysis should be instituted as early as possible. Furthermore, in a severely burnt patient with episodes of chronic and acute intoxication from organic chemicals or drugs which may have caused renal damage, acute renal failure may occur, so that careful observation is advised. PMID:6525538
Jeschke, Marc G.; Kulp, Gabriela A.; Kraft, Robert; Finnerty, Celeste C.; Mlcak, Ron; Lee, Jong O.; Herndon, David N.
Rationale: Hyperglycemia and insulin resistance have been shown to increase morbidity and mortality in severely burned patients, and glycemic control appears essential to improve clinical outcomes. However, to date no prospective randomized study exists that determines whether intensive insulin therapy is associated with improved post-burn morbidity and mortality. Objectives: To determine whether intensive insulin therapy is associated with improved post-burn morbidity. Methods: A total of 239 severely burned pediatric patients with burns over greater than 30% of their total body surface area were randomized (block randomization 1:3) to intensive insulin treatment (n = 60) or control (n = 179). Measurements and Main Results: Demographics, clinical outcomes, sepsis, glucose metabolism, organ function, and inflammatory, acute-phase, and hypermetabolic responses were determined. Demographics were similar in both groups. Intensive insulin treatment significantly decreased the incidence of infections and sepsis compared with controls (P < 0.05). Furthermore, intensive insulin therapy improved organ function as indicated by improved serum markers, DENVER2 scores, and ultrasound (P < 0.05). Intensive insulin therapy alleviated post-burn insulin resistance and the vast catabolic response of the body (P < 0.05). Intensive insulin treatment dampened inflammatory and acute-phase responses by deceasing IL-6 and acute-phase proteins compared with controls (P < 0.05). Mortality was 4% in the intensive insulin therapy group and 11% in the control group (P = 0.14). Conclusions: In this prospective randomized clinical trial, we showed that intensive insulin therapy improves post-burn morbidity. Clinical trial registered with www.clinicaltrials.gov (NCT00673309). PMID:20395554
Chen, Bi; Jia, Chi-yu; Hu, Da-hai; Zhu, Xiong-xiang; Han, Jun-tao; Yao, Qing-jun; Xu, Ming-da
To explore new measures for functional reconstruction of multiple severe deformities as a result of extensive deep burn (total burn surface area > or = 90% TBSA, including deep burn > or = 70%TBSA) in late stage. Twelve severe burn patients with above-mentioned deformities were hospitalized in our ward during 1960--2005, the scars resulted from burns were distributed from head to foot with 173 deformities, including 27 scar ulcers. All patients lacked of self-care ability, among them some could not stand. Due to inadequate skin source, deformities were corrected by skin from matured scars expanded with subcutaneous balloon at late postburn stage. Following our former clinical experience, anatomic investigation and experimental research, we chose the following methods to correct deformities and restore functions: application of split-thickness scar skin after expansion (88 wounds); use of scar skin flap/scar-Achilles tendon flaps (59 wounds); combination of thin split-thickness skin grafts from scar and allogeneic acellular dermal matrix (composite skin, 40 wounds). All grafts survived, the appearance and function were improved obviously without complications. Follow-up 1-40 years, all patients could take care themselves with satisfactory function and appearance, and among them 8 patients returned to work (one had worked for 40 years), 2 patients married and had children. The above-mentioned measures are safe, reliable and effective for functional reconstruction of deformities. PMID:19103016
Jones, B. M.; Grosse, G.; Larsen, C. F.; Hayes, D. J.; Arp, C. D.; Liu, L.; Miller, E.
Wildfire disturbance in northern high latitude regions is an important factor contributing to ecosystem and landscape change. In permafrost influenced terrain, fire may initiate thermokarst development which impacts hydrology, vegetation, wildlife, carbon storage and infrastructure. In this study we differenced two airborne LiDAR datasets that were acquired in the aftermath of the large and severe Anaktuvuk River tundra fire, which in 2007 burned across a proposed road corridor in Arctic Alaska. The 2009 LiDAR dataset was acquired by the Alaska Department of Transportation in preparation for construction of a gravel road that would connect the Dalton Highway with the logistical camp of Umiat. The 2014 LiDAR dataset was acquired by the USGS to quantify potential post-fire thermokarst development over the first seven years following the tundra fire event. By differencing the two 1 m resolution digital terrain models, we measured permafrost thaw subsidence across 34% of the burned tundra area studied, and observed less than 1% in similar, undisturbed tundra terrain units. Ice-rich, yedoma upland terrain was most susceptible to thermokarst development following the disturbance, accounting for 50% of the areal and volumetric change detected, with some locations subsiding more than six meters over the study period. Calculation of rugosity, or surface roughness, in the two datasets showed a doubling in microtopography on average across the burned portion of the study area, with a 340% increase in yedoma upland terrain. An additional LiDAR dataset was acquired in April 2015 to document the role of thermokarst development on enhanced snow accumulation and subsequent snowmelt runoff within the burn area. Our findings will enable future vulnerability assessments of ice-rich permafrost terrain as a result of shifting disturbance regimes. Such assessments are needed to address questions focused on the impact of permafrost degradation on physical, ecological, and socio
Di, Xue-ying; Tao, Yu-zhu
The occurrence of the secondary disasters of forest fire has significant impacts on the environment quality and human health and safety. Post-fire debris flow is one of the most hazardous secondary disasters of forest fire. To understand the occurrence conditions of post-fire debris flow and to master its occurrence situation are the critical elements in post-fire hazard assessment. From the viewpoints of vegetation, precipitation threshold and debris flow material sources, this paper elaborated the impacts of forest fire on the debris flow, analyzed the geologic and geomorphic conditions, precipitation and slope condition that caused the post-fire debris flow as well as the primary mechanisms of debris-flow initiation caused by shallow landslide or surface runoff, and reviewed the research progress in the prediction and forecast of post-fire debris flow and the related control measures. In the future research, four aspects to be focused on were proposed, i. e., the quantification of the relationships between the fire behaviors and environmental factors and the post-fire debris flow, the quantitative research on the post-fire debris flow initiation and movement processes, the mechanistic model of post-fire debris flow, and the rapid and efficient control countermeasures of post-fire debris flow. PMID:24380363
O'Halloran, T. L.; Acker, S. A.; Joerger, V.; Kertis, J.; Law, B. E.
We examine albedo perturbation and associated radiative forcing after a high-severity fire in a mature forest in the Oregon Cascade Range. Correlations between post-fire albedo and seedling, sapling, and standing dead tree (snag) density were investigated across fire severity classes and seasons for years 4-15 after fire. Albedo perturbation was 14 times larger in winter compared to summer and increased with fire severity class for the first several years after fire. Summer and winter albedo perturbation increased approximately linearly over the study period. Albedo correlations were strongest with snags, and significant in all fire classes in both summer and winter. The resulting annual radiative forcing at the top of the atmosphere decreased (became more negative) linearly for the first 15 years after fire. These results suggest that snags, more than recovering vegetation, can control the shortwave energy balance of the burned land surface. As such, the dynamics of snag attrition may need to be included in coupled land-atmosphere models to properly represent the climate impacts of wildfire.
Lundy, Jonathan B; Chung, Kevin K; Pamplin, Jeremy C; Ainsworth, Craig R; Jeng, James C; Friedman, Bruce C
Thermal injury of humans causes arguably the most severe perturbations in physiology that can be experienced. These physiologic derangements start immediately and can persist in some form until months or even years after the burn wounds are healed. Burn shock, marked activation of the systemic inflammatory response, multiple-organ failure, infection, and wound failure are just a few of the insults that may require management by the intensivist. The purpose of this article is to review recent advances in the critical care management of thermally injured patients. PMID:26112758
van Leeuwen, Willem J. D.
This study examines how satellite based time-series vegetation greenness data and phenological measurements can be used to monitor and quantify vegetation recovery after wildfire disturbances and examine how pre-fire fuel reduction restoration treatments impact fire severity and impact vegetation recovery trajectories. Pairs of wildfire affected sites and a nearby unburned reference site were chosen to measure the post-disturbance recovery in relation to climate variation. All site pairs were chosen in forested uplands in Arizona and were restricted to the area of the Rodeo-Chediski fire that occurred in 2002. Fuel reduction treatments were performed in 1999 and 2001. The inter-annual and seasonal vegetation dynamics before, during, and after wildfire events can be monitored using a time series of biweekly composited MODIS NDVI (Moderate Resolution Imaging Spectroradiometer - Normalized Difference Vegetation Index) data. Time series analysis methods included difference metrics, smoothing filters, and fitting functions that were applied to extract seasonal and inter-annual change and phenological metrics from the NDVI time series data from 2000 to 2007. Pre- and post-fire Landsat data were used to compute the Normalized Burn Ratio (NBR) and examine burn severity at the selected sites. The phenological metrics (pheno-metrics) included the timing and greenness (i.e. NDVI) for the start, peak and end of the growing season as well as proxy measures for the rate of green-up and senescence and the annual vegetation productivity. Pre-fire fuel reduction treatments resulted in lower fire severity, which reduced annual productivity much less than untreated areas within the Rodeo-Chediski fire perimeter. The seasonal metrics were shown to be useful for estimating the rate of post-fire disturbance recovery and the timing of phenological greenness phases. The use of satellite time series NDVI data and derived pheno-metrics show potential for tracking vegetation cover dynamics
Staley, Dennis M.; Negri, Jacquelyn A.; Kean, Jason W.; Laber, Jayme L.; Tillery, Anne C.; Youberg, Ann M.
Wildfire can significantly alter the hydrologic response of a watershed to the extent that even modest rainstorms can generate dangerous flash floods and debris flows. To reduce public exposure to hazard, the U.S. Geological Survey produces post-fire debris-flow hazard assessments for select fires in the western United States. We use publicly available geospatial data describing basin morphology, burn severity, soil properties, and rainfall characteristics to estimate the statistical likelihood that debris flows will occur in response to a storm of a given rainfall intensity. Using an empirical database and refined geospatial analysis methods, we defined new equations for the prediction of debris-flow likelihood using logistic regression methods. We showed that the new logistic regression model outperformed previous models used to predict debris-flow likelihood.
Chan, Rodney K; Aden, James; Wu, Jesse; Hale, Robert G; Renz, Evan M; Wolf, Steven E
The goal of burn surgical therapy is to minimize mortality and to return survivors to their preinjury state. Prompt removal of the burn eschar, early durable coverage, and late corrections of functional deformities are the basic surgical principles. The operative burden, while presumed to be substantial and significant, is neither well described nor quantified. The burn registry at the U.S. Institute of Surgical Research Burn Center was queried from March 2003 to August 2011 for all active duty burn admissions; active duty subjects were chosen to eliminate subject follow-up as a significant variable. Subject demographics including age, sex, branch of service, injury type, injury severity score, transfusion, allograft use, length of stay, mechanism of injury, and survival were tabulated as were their percentage TBSA, specific body region involvement, and nature and dates of operations performed. Univariate analysis and multiple logistic regressions were performed to determine independent factors which predict early and late operative burden. In the 8-year study period, 864 active duty patients were admitted to the burn center. Among them, 569 (66%) were operative in nature. The operations that were performed during acute hospitalization were 62%, while the remaining 38% were performed following discharge. A linear relationship exists between TBSA and the number of acute operations with an average of one acute operation required per 5% TBSA. No direct relationships however were found between TBSA and the number of reconstructive operations. Based on multiple logistic regression, battle vs nonbattle (odds ratio [OR], 0.559; 95% confidence interval [CI], 0.298-1.050; P = .0706), injury severity score (OR, 1.021; 95% CI, 1.003-1.039; P = .0222), intensive care unit length of stay (OR, 1.076; 95% CI, 1.053-1.099; P ≤ .0001), allograft use (OR, 2.610; 95% CI, 1.472-4.628; P = .0010), and TBSA of the trunk (OR, 0.982; 95% CI, 0.965-1.000; P = .0439) (but not overall TBSA
Kinoshita, A. M.; Hogue, T. S.; Kim, J.
Wildfires are increasing in intensity and size across the western US, and more than half of the 20 largest fires in California have occurred within the last decade. Development in southern California has increased and as a result many homes at the wildland-urban interface (WUI) are affected by fire events themselves and post-fire processes. Current management efforts are mostly concentrated around immediate post-fire effects (first storm season); however, burned systems are often altered for prolonged periods of time, creating long-term concerns for downstream communities at the WUI. Previous work in two southern Californian watersheds, City Creek and Devil Canyon, shows lack of vegetation recovery and significant changes in annual and seasonal discharge for the post-fire study period (seven years). Applying remotely sensed data streams enhances monitoring of large and ungauged burned areas at high spatial and temporal resolutions. The goal of the current study is to integrate remote sensing data from multiple satellite platforms to improve prediction of the spatial and temporal variability of key hydrological variables controlling post-fire response. Remote sensing data streams from Moderate-resolution Imaging Spectroradiometer (MODIS) and Landsat are used to derive a range of land surface parameters and evaluate ecosystem and hydrologic recovery for the Arroyo Seco, an urban-fringe watershed in southern California burned by the 2009 Station Fire. A UCLA remotely-sensed evapotranspiration (ET) product is used to provide insight on vegetation growth and plant water availability. A UCLA MODIS-AMSR-E soil moisture product is used to evaluate the spatial variability of post-fire surface soil moisture and coupled storm runoff response. A range of other parameters, surface temperature, albedo and vegetation indices, are also evaluated to provide insight on the spatial variability of watershed recovery. Predicting the short and long-term risks of post-fire floods, debris
Li, Hongming; Zhang, Jiaping; Chen, Jian; Song, Huapei; Liu, Qiushi; Fan, Xin; Peng, Yizhi; Wu, Jun
This article reports the successful experience of integration of burn treatment and rehabilitation for a child suffering from 91% TBSA flame burn injury (with 60% TBSA full-thickness injury, 30% TBSA deep partial-thickness injury, and 1% TBSA superficial partial-thickness injury), severe inhalation injury, severe burn shock, stress ulcer, gastrointestinal bleeding and atelectasis of the right upper lung. The patient was given effective fluid infusion against shock, treatment for gastrointestinal bleeding, and other effective supportive treatment for functions of various organs after being admitted to our burn ward. When vital signs became stable at 30 hours post injury, bedside rehabilitation was begun. On post injury day (PID) 4, escharectomy was performed for both lower limbs, followed by microskin grafting and allogeneic skin covering. On PID 10, invasive infection of multi-drug resistant bacteria was found with accompanied high fever, and at the same time allograft began to disintegrate, with dissolution of large area of eschar, leading to a raw surface reaching 86% TBSA. Following debridement, dressing, application of compound polymyxin B ointment, temporary covering of wounds with porcine acellular dermal matrix, adjustment of antibiotics, patient's condition was finally stabilized. From PID 28 on, split-thickness skin grafting was conducted 7 times, and the raw surface of 75% TBSA involving the upper and lower limbs and trunk was successfully covered. At the same time, our rehabilitation team launched comprehensive rehabilitation measures comprising active exercise, occupational therapy, prevention of scar formation, organ function training and psychological intervention. Finally, the patient was able to walk unaided and fed herself when the wounds were almost entirely healed in 3 months after injury. Oriented forwards functional rehabilitation, strong cooperation between team members, and synchronous effective implementation of burn treatment and
Brumby, Steven P.; Harvey, Neal R.; Bloch, Jeffrey J.; Theiler, James P.; Perkins, Simon J.; Young, Aaron C.; Szymanski, John J.
Between May 6 and May 18, 2000, the Cerro Grande/Los Alamos wildfire burned approximately 43,000 acres (17,500 ha) and 235 residences in the town of Los Alamos, NM. Initial estimates of forest damage included 17,000 acres (6,900 ha) of 70-100% tree mortality. Restoration efforts following the fire were complicated by the large scale of the fire, and by the presence of extensive natural and man-made hazards. These conditions forced a reliance on remote sensing techniques for mapping and classifying the burn region. During and after the fire, remote-sensing data was acquired from a variety of aircraft-based and satellite-based sensors, including Landsat 7. We now report on the application of a machine learning technique, implemented in a software package called GENIE, to the classification of forest fire burn severity using Landsat 7 ETM+ multispectral imagery. The details of this automatic classification are compared to the manually produced burn classification, which was derived from field observations and manual interpretation of high-resolution aerial color/infrared photography.
Picotte, Joshua J.; Peterson, Birgit; Meier, Gretchen; Howard, Stephen M.
Burn severity products created by the Monitoring Trends in Burn Severity (MTBS) project were used to analyse historical trends in burn severity. Using a severity metric calculated by modelling the cumulative distribution of differenced Normalized Burn Ratio (dNBR) and Relativized dNBR (RdNBR) data, we examined burn area and burn severity of 4893 historical fires (1984–2010) distributed across the conterminous US (CONUS) and mapped by MTBS. Yearly mean burn severity values (weighted by area), maximum burn severity metric values, mean area of burn, maximum burn area and total burn area were evaluated within 27 US National Vegetation Classification macrogroups. Time series assessments of burned area and severity were performed using Mann–Kendall tests. Burned area and severity varied by vegetation classification, but most vegetation groups showed no detectable change during the 1984–2010 period. Of the 27 analysed vegetation groups, trend analysis revealed burned area increased in eight, and burn severity has increased in seven. This study suggests that burned area and severity, as measured by the severity metric based on dNBR or RdNBR, have not changed substantially for most vegetation groups evaluated within CONUS.
Severe disturbance from catastrophic wildfires often requires that native plant materials be reintroduced through reseeding, but the success rate of these restoration efforts in arid environments is notoriously low. Post-fire soil water repellency can limit reseeding success by decreasing soil moist...
This study demonstrates the novel application of genetic programming to evolve nonlinear post-fire debris-flow volume equations from variables associated with a data-driven conceptual model of the western United States. The search space is constrained using a multi-component objective function that simultaneously minimizes root-mean squared and unit errors for the evolution of fittest equations. An optimization technique is then used to estimate the limits of nonlinear prediction uncertainty associated with the debris-flow equations. In contrast to a published multiple linear regression three-variable equation, linking basin area with slopes greater or equal to 30 percent, burn severity characterized as area burned moderate plus high, and total storm rainfall, the data-driven approach discovers many nonlinear and several dimensionally consistent equations that are unbiased and have less prediction uncertainty. Of the nonlinear equations, the best performance (lowest prediction uncertainty) is achieved when using three variables: average basin slope, total burned area, and total storm rainfall. Further reduction in uncertainty is possible for the nonlinear equations when dimensional consistency is not a priority and by subsequently applying a gradient solver to the fittest solutions. The data-driven modeling approach can be applied to nonlinear multivariate problems in all fields of study. ?? 2011.
Miller, Mark E.; Bowker, Matthew A.; Reynolds, Richard L.; Goldstein, Harland L.
We monitored sediment flux at 25 plots located at the northern end of the 2007 Milford Flat Fire (Lake Bonneville Basin, west-central Utah) to examine the effectiveness of post-fire rehabilitation treatments in mitigating risks of wind erosion during the first 3 years post fire. Maximum values were recorded during Mar–Jul 2009 when horizontal sediment fluxes measured with BSNE samplers ranged from 16.3 to 1251.0 g m−2 d−1 in unburned plots (n = 8; data represent averages of three sampler heights per plot), 35.2–555.3 g m−2 d−1 in burned plots that were not treated (n = 5), and 21.0–44,010.7 g m−2 d−1 in burned plots that received one or more rehabilitation treatments that disturbed the soil surface (n = 12). Fluxes during this period exhibited extreme spatial variability and were contingent on upwind landscape characteristics and surficial soil properties, with maximum fluxes recorded in settings downwind of treated areas with long treatment length and unstable fine sand. Nonlinear patterns of wind erosion attributable to soil and fetch effects highlight the profound importance of landscape setting and soil properties as spatial factors to be considered in evaluating risks of alternative post-fire rehabilitation strategies. By Mar–Jul 2010, average flux for all plots declined by 73.6% relative to the comparable 2009 period primarily due to the establishment and growth of exotic annual plants rather than seeded perennial plants. Results suggest that treatments in sensitive erosion-prone settings generally exacerbated rather than mitigated wind erosion during the first 3 years post fire, although long-term effects remain uncertain.
Miller, Mark E.; Bowker, Matthew A.; Reynolds, Richard L.; Goldstein, Harland L.
We monitored sediment flux at 25 plots located at the northern end of the 2007 Milford Flat Fire (Lake Bonneville Basin, west-central Utah) to examine the effectiveness of post-fire rehabilitation treatments in mitigating risks of wind erosion during the first 3 years post fire. Maximum values were recorded during Mar-Jul 2009 when horizontal sediment fluxes measured with BSNE samplers ranged from 16.3 to 1251.0 g m-2 d-1 in unburned plots (n = 8; data represent averages of three sampler heights per plot), 35.2-555.3 g m-2 d-1 in burned plots that were not treated (n = 5), and 21.0-44,010.7 g m-2 d-1 in burned plots that received one or more rehabilitation treatments that disturbed the soil surface (n = 12). Fluxes during this period exhibited extreme spatial variability and were contingent on upwind landscape characteristics and surficial soil properties, with maximum fluxes recorded in settings downwind of treated areas with long treatment length and unstable fine sand. Nonlinear patterns of wind erosion attributable to soil and fetch effects highlight the profound importance of landscape setting and soil properties as spatial factors to be considered in evaluating risks of alternative post-fire rehabilitation strategies. By Mar-Jul 2010, average flux for all plots declined by 73.6% relative to the comparable 2009 period primarily due to the establishment and growth of exotic annual plants rather than seeded perennial plants. Results suggest that treatments in sensitive erosion-prone settings generally exacerbated rather than mitigated wind erosion during the first 3 years post fire, although long-term effects remain uncertain.
Shenoy, A.; Kielland, K.; Johnstone, J. F.
Increases in the frequency, extent, and severity of fire in the North American boreal region are projected to continue under a warming climate and are likely to be associated with changes in future vegetation composition. In interior Alaska, fire severity is linked to the relative dominance of deciduous versus coniferous canopy species. Severely burned areas have high levels of deciduous recruitment and subsequent stand dominance, while lightly burned areas exhibit black spruce self-replacement. To elucidate potential mechanisms by which differential fire severity results in differential post-fire vegetation development, we examined changes in soil nitrogen (N) supply (NO3- and NH4+) and in situ 15N uptake by young aspen (Populus tremuloides) and black spruce (Picea mariana) trees growing in lightly and severely burned areas. We hypothesized that (a) soil nitrate supply would be higher in severely burned sites and (b) since conifers have been shown to have a reduced physiological capacity for NO3- uptake, aspen would display greater rates of NO3- uptake than spruce in severely burned sites. Our results suggested that the composition and magnitude of inorganic N supply 14 years after the fire was nearly identical in high-severity and low-severity sites, and nitrate represented nearly 50% of the supply. However, both aspen and spruce took up substantially more NH4+-N than NO3- -N regardless of fire severity. Surprisingly, spruce exhibited only a moderately lower rate of NO3- uptake (μg N/g root-1h-1) than aspen. At the stand level, aspen took up nearly an order-of-magnitude more N per hectare in severely burned sites compared to lightly burned sites, while spruce exhibited the opposite pattern of N uptake with respect to fire severity. Whereas ammonium appeared to be preferred by both species, nitrate represented a larger component of N uptake (based on the NO3-:NH4+ uptake ratio) in aspen (0.7) than in spruce (0.4). We suggest that these species
Elliott, J.G.; Parker, R.S.
Stratigraphic and geomorphic evidence indicate floods that occur soon after forest fires have been intermittent but common events in many mountainous areas during the past several thousand years. The magnitude and recurrence of these post-fire flood events reflects the joint probability between the recurrence of fires and the recurrence of subsequent rainfall events of varying magnitude and intensity. Following the May 1996 Buffalo Creek, Colorado, forest fire, precipitation amounts and intensities that generated very little surface runoff outside of the burned area resulted in severe hillslope erosion, floods, and streambed sediment entrainment in the rugged, severely burned, 48 km2 area. These floods added sediment to many existing alluvial fans, while simultaneously incising other fans and alluvial deposits. Incision of older fans revealed multiple sequences of fluvially transported sandy gravel that grade upward into charcoal-rich, loamy horizons. We interpret these sequences to represent periods of high sediment transport and aggradation during floods, followed by intervals of quiescence and relative stability in the watershed until a subsequent fire occurred. An alluvial sequence near the mouth of a tributary draining a 0??82 km2 area indicated several previous post-fire flood cycles in the watershed. Dendrochronologic and radiocarbon ages of material in this deposit span approximately 2900 years, and define three aggradational periods. The three general aggradational periods are separated by intervals of approximately nine to ten centuries and reflect a 'millennium-scale' geomorphic response to a closely timed sequence of events: severe and intense, watershed-scale, stand-replacing fires and subsequent rainstorms and flooding. Millennium-scale aggradational units at the study site may have resulted from a scenario in which the initial runoff from the burned watershed transported and deposited large volumes of sediment on downstream alluvial surfaces and
Elliott, John G.; Parker, R. S.
Stratigraphic and geomorphic evidence indicate floods that occur soon after forest fires have been intermittent but common events in many mountainous areas during the past several thousand years. The magnitude and recurrence of these post-fire flood events reflects the joint probability between the recurrence of fires and the recurrence of subsequent rainfall events of varying magnitude and intensity. Following the May 1996 Buffalo Creek, Colorado, forest fire, precipitation amounts and intensities that generated very little surface runoff outside of the burned area resulted in severe hillslope erosion, floods, and streambed sediment entrainment in the rugged, severely burned, 48 km2 area. These floods added sediment to many existing alluvial fans, while simultaneously incising other fans and alluvial deposits. Incision of older fans revealed multiple sequences of fluvially transported sandy gravel that grade upward into charcoal-rich, loamy horizons. We interpret these sequences to represent periods of high sediment transport and aggradation during floods, followed by intervals of quiescence and relative stability in the watershed until a subsequent fire occurred.An alluvial sequence near the mouth of a tributary draining a 0·82 km2 area indicated several previous post-fire flood cycles in the watershed. Dendrochronologic and radiocarbon ages of material in this deposit span approximately 2900 years, and define three aggradational periods. The three general aggradational periods are separated by intervals of approximately nine to ten centuries and reflect a millennium-scale geomorphic response to a closely timed sequence of events: severe and intense, watershed-scale, stand-replacing fires and subsequent rainstorms and flooding. Millennium-scale aggradational units at the study site may have resulted from a scenario in which the initial runoff from the burned watershed transported and deposited large volumes of sediment on downstream alluvial surfaces and
Miller, Mary Ellen; MacDonald, Lee H.; Billmire, Michael; Elliot, William J.; Robichaud, Pete R.
Rapid response is critical following natural disasters. Flooding, erosion, and debris flows are a major threat to life, property and municipal water supplies after moderate and high severity wildfires. The problem is that mitigation measures must be rapidly implemented if they are to be effective, but they are expensive and cannot be applied everywhere. Fires, runoff, and erosion risks also are highly heterogeneous in space, so there is an urgent need for a rapid, spatially-explicit assessment. Past post-fire modeling efforts have usually relied on lumped, conceptual models because of the lack of readily available, spatially-explicit data layers on the key controls of topography, vegetation type, climate, and soil characteristics. The purpose of this project is to develop a set of spatially-explicit data layers for use in process-based models such as WEPP, and to make these data layers freely available. The resulting interactive online modeling database (http://geodjango.mtri.org/geowepp/) is now operational and publically available for 17 western states in the USA. After a fire, users only need to upload a soil burn severity map, and this is combined with the pre-existing data layers to generate the model inputs needed for spatially explicit models such as GeoWEPP (Renschler, 2003). The development of this online database has allowed us to predict post-fire erosion and various remediation scenarios in just 1-7 days for six fires ranging in size from 4-540 km2. These initial successes have stimulated efforts to further improve the spatial extent and amount of data, and add functionality to support the USGS debris flow model, batch processing for Disturbed WEPP (Elliot et al., 2004) and ERMiT (Robichaud et al., 2007), and to support erosion modeling for other land uses, such as agriculture or mining. The design and techniques used to create the database and the modeling interface are readily repeatable for any area or country that has the necessary topography
Bento, C. P. M.; Shakesby, R. A.; Walsh, R. P. D.; Ferreira, C. S. S.; Ferreira, A. J. D.; Urbanek, E.
conditions. In a second phase, a representative amount (8.34 kg) of fermented litter and shrubs from a pine plantation was applied evenly to each of five lysimeters. In a third stage, four of the five treated lysimeters were burned to simulate a low-severity wildfire. After several more rainfall events, pine needles (37.7% cover) were applied to two of the burnt lysimeters. In the final stage, there was 1 lysimeter with bare soil, 1 unburnt with a vegetation cover, 2 burnt and untreated, and 2 burnt with needles. In all the lysimeters, runoff and percolated water were monitored during the entire study, as were the amounts of eroded sediment and organic matter contents for runoff. Calculating the erosion-limiting effect of needles was conducted in a similar fashion to (1) and based on results from stages 3 and 4. The results from both experiments show that the needles reduced erosion by as much as c.60% compared with the corresponding control situation, indicating that a needlecast 'carpet' is likely to be able to provide a highly effective, simple, cheap means of significantly reducing post-fire soil loss in pine forests where the tree canopies have been scorched but not consumed by fire.
Burns extending deep into the skin and those affecting a wide surface area trigger various responses in the body and pose a serious threat to life. Therefore, the degree of severity needs to be determined accurately, and appropriate transfusion and local management should be provided accordingly. Systematic and meticulous management that considers not just the risk of death but also functional prognosis is essential from the early stage of burn injuries. Such management requires comprehensive care by a medical team concerning infections, nutrition and rehabilitation. This article outlines the current status of intensive care for severe burns. PMID:26915244
Introduction Intensive insulin treatment (IIT) has been shown to improve outcomes post-burn in severely burnt patients. However, it increases the incidence of hypoglycemia and is associated with risks and complications. We hypothesized that exenatide would decrease plasma glucose levels post-burn to levels similar to those achieved with IIT, and reduce the amount of exogenous insulin administered. Methods This open-label study included 24 severely burned pediatric patients. Six were randomized to receive exenatide, and 18 received IIT during acute hospitalization (block randomization). Exenatide and insulin were administered to maintain glucose levels between 80 and 140 mg/dl. We determined 6 AM, daily average, maximum and minimum glucose levels. Variability was determined using mean amplitude of glucose excursions (MAGE) and percentage of coefficient of variability. The amount of administered insulin was compared in both groups. Results Glucose values and variability were similar in both groups: Daily average was 130 ± 28 mg/dl in the intervention group and 138 ± 25 mg/dl in the control group (P = 0.31), MAGE 41 ± 6 vs. 45 ± 12 (respectively). However, administered insulin was significantly lower in the exenatide group than in the IIT group: 22 ± 14 IU patients/day in the intervention group and 76 ± 11 IU patients/day in the control group (P = 0.01). The incidence rate of hypoglycemia was similar in both groups (0.38 events/patient-month). Conclusions Patients receiving exenatide received significantly lower amounts of exogenous insulin to control plasma glucose levels. Exenatide was well tolerated and potentially represents a novel agent to attenuate hyperglycemia in the critical care setting. Trial registration NCT00673309. PMID:20701787
Miller, Mary Ellen; Elliot, William E.; MacDonald, Lee H.
Once the danger posed by an active wildfire has passed, land managers must rapidly assess the threat from post-fire runoff and erosion due to the loss of surface cover and fire-induced changes in soil properties. Increased runoff and sediment delivery are of great concern to both the pubic and resource managers. Post-fire assessments and proposals to mitigate these threats are typically undertaken by interdisciplinary Burned Area Emergency Response (BAER) teams. These teams are under very tight deadlines, so they often begin their analysis while the fire is still burning and typically must complete their plans within a couple of weeks. Many modeling tools and datasets have been developed over the years to assist BAER teams, but process-based, spatially explicit models are currently under-utilized relative to simpler, lumped models because they are more difficult to set up and require the preparation of spatially-explicit data layers such as digital elevation models, soils, and land cover. The difficulty of acquiring and utilizing these data layers in spatially-explicit models increases with increasing fire size. Spatially-explicit post-fire erosion modeling was attempted for a small watershed in the 1270 km2 Rock House fire in Texas, but the erosion modeling work could not be completed in time. The biggest limitation was the time required to extract the spatially explicit soils data needed to run the preferred post-fire erosion model (GeoWEPP with Disturbed WEPP parameters). The solution is to have the spatial soil, land cover, and DEM data layers prepared ahead of time, and to have a clear methodology for the BAER teams to incorporate these layers in spatially-explicit modeling interfaces like GeoWEPP. After a fire occurs the data layers can quickly be clipped to the fire perimeter. The soil and land cover parameters can then be adjusted according to the burn severity map, which is one of the first products generated for the BAER teams. Under a previous project
Vieira, Diana; Nunes, João; Prats, Sergio; Serpa, Dalila; Keizer, Jan
Wildfires have become a recurrent threat for many forest ecosystems of the Mediterranean. The characteristics of the Mediterranean climate with its warm and dry summers and mild and wet winters make it prone to wildfire occurrence as well as to post-fire soil erosion. Furthermore, climate change and continuation of current land management practices and planning are generally expected to further increase this threat. The wide recognition of the effects of wildfires to enhance runoff and erosion has created a strong demand for model-based tools for predicting the post-fire hydrological and erosion response and, in particular, for predicting the effectiveness of post-fire forestry operations to mitigate these responses. Such a tool should allow to identify areas with elevated risks of soil erosion and to evaluate which measures should be applied and when to minimize these risks. A key element in evaluating these measures is also their costs, in order to optimize the use of the limited resources that are typically available for post-fire land management. In this study, two "treatments" are compared with control conditions (i.e. doing nothing) after a wildfire with a moderate soil burn severity: (i) 4 erosion plots were treated with hydro-mulch, (ii) 4 erosion plots were untreated but had a high pine needle cover quickly after the fire, due to needle cast from scorched pine crowns (often referred to as "natural mulching") (iii) 4 plots were untreated and had a very reduced protective litter cover . The main objective of this study was to asses if the revised MMF model could effectively predict the impacts of hydro-mulching and natural mulching with pine needle on runoff generation and the associated soil losses. If MMF could predict well the impact of natural mulching, it could be very useful in limiting the areas that should be considered for specific soil mitigation measures, especially in the case of wildfires that affect large areas with moderate severity. The
Gouveia, C. M.; Bastos, A.; Trigo, R. M.; DaCamara, C.
In 2004/2005, the Iberian Peninsula was stricken by an exceptional drought that affected more than one third of Portugal and part of southern Spain during more than 9 months. This severe drought had a strong negative impact on vegetation dynamics, as it coincided with the period of high photosynthetic activity (Gouveia et al., 2009). Since water availability is a crucial factor in post-fire vegetation recovery, it is desirable to assess the impact that such water-stress conditions had on fire sensitivity and post-fire vegetation recovery. Fire events in the European Mediterranean areas have become a serious problem and a major ecosystem disturbance, increasing erosion and soil degradation. In Portugal, the years 2003 and 2005 were particularly devastating. In 2003 it was registered the maximal burnt area since 1980, with more than 425000 ha burned, representing about 5% of Portuguese mainland. The 2005 fire season registered the highest number of fire occurrences in Portugal and the second year with the greatest number of fires in Spain. The high number of fire events observed during the summer 2005 in the Iberian Peninsula is linked, in part, to the extreme drought conditions that prevailed during the preceding winter and spring seasons of 2004/2005. Vegetation recovery after the 2003 and 2005 fire seasons was estimated using the mono-parametric model developed by Gouveia et al. (2010), which relies on monthly values of Normalized Difference Vegetation Index (NDVI), from 1999 to 2009, at 1kmresolution, as obtained from the VEGETATION-SPOT5 instrument.. This model was further used to evaluate the effect of drought in pre and post vegetation activity. Besides the standard NDVI, the Normalized Difference Water Index (NDWI) and the Normalized Difference Drought Index (NDDI) were computed in order to evaluate drought intensity. In the case of the burnt scars of 2003, when data corresponding to the months of drought are removed, recovery times are considerably shorter
Carrington, M.E.; Keeley, J.E.
I Both fire regimes and the conditions under which fires occur vary widely. Abiotic conditions (such as climate) in combination with fire season, frequency and intensity could influence vegetation responses to fire. A variety of adaptations facilitate post-fire recruitment in mediterranean climate ecosystems, but responses of other communities are less well known. We evaluated the importance of climate by comparing sites with mediterranean and subtropical climates. 2 We used paired burned and mature sites in chamise chaparral, mixed chaparral and coastal sage scrub (California), and rosemary scrub, sand pine scrub and sand-hill (Florida), to test whether (i) patterns of pre-fire and post-fire seedling recruitment are more similar between communities within a region than between regions, and (ii) post-fire stimulation of seedling establishment is greater in regions with marked fire-induced contrasts in abiotic site characteristics. 3 Post-fire seedling densities were more similar among sites within climatic regions than between regions. Both seedling densities and proportions of species represented by seedlings after fires were generally higher in California. 4 The only site characteristic showing a pre-fire-post-fire contrast was percentage open canopy, and the effect was greater in California than in Florida. Soil properties were unaffected by fire. 5 Mediterranean climate ecosystems in other regions have nutrient-poor soils similar to our subtropical Florida sites, but show post-fire seedling recruitment patterns more similar to the nutrient-rich sites in California. Climate therefore appears to play a more major role than soil characteristics.
Pontini, A; Reho, F; Giatsidis, G; Bacci, C; Azzena, B; Tiengo, C
Oral burns in pediatric patient are commonly due to electrical injuries, representing an important reconstructive issue even for functional than esthetic reason. Different classification, surgical management and even oral device were described to allow the best long-term result. In most case a multidisciplinary approach is necessary to achieve a satisfactory outcome. A severe case of pediatric oral burn with germinative teeth damage is presented, describing a multispecialist team approach that guarantee a satisfactory outcome by reconstructive surgery, careful progressive evaluation of dental and soft tissue healing and speech recovery. The use of acellular dermal substitute template within traditional reconstructive surgery had provided a good functional and esthetic result joint to valid preservation of germinative dental element as shown at long-term X-ray evaluation. Intensive rehabilitation speech program has also avoided phonetic impairment in an important speech develop period. It was so evident that the necessity of a multispecialist care in such difficult injury to achieve the best long-term result. PMID:25716757
De Luis, Martin; Raventós, José; González-Hidalgo, José Carlos
In Western Mediterranean areas, forest fires are frequent in forests established on old croplands where post-fire regeneration is limited to obligate-seeder species. This has resulted in the spread of Mediterranean gorse ( Ulex parviflorus) increasing the risk and severity of fires. The aim of this paper is to test the autosuccessional hypothesis on a Mediterranean gorse shrubland dominated by seeders species. Particular objectives are: a) to analyze the effect of fire on seedling emergence, survival and growth on the main species involved on plant regeneration process. b) to identify changes in the relative abundance of species as consequence of fire by using a before-after experiment. Then, after experimental fires, seedling emergence, survival and growth rates were analyzed for the main species present in the vegetation regeneration process. Our results show that Mediterranean gorse communities are dominated by Fabaceae species (64% of individuals, mainly of Ulex parviflorus). However, our study demonstrates that vegetation regeneration after fire does not display an autosuccessional pattern and is produced a change on dominance from Fabaceae (mainly U. parviflorus) to Cistaceae (mainly C. albidus) species. Cistaceae seedlings (mainly Cistus albidus and Helianthemum marifolium) were the most abundant post-fire (63% of total germination) while species of Fabaceae (including U. parviflorus and Ononis fruticosa) represented 25%, and Lamiaceae (restricted to Rosmarinus officinalis) comprised only 3% of total emergences. Seedling survival did not differ significantly from one species to another (25-30% of initial individuals over 3 years) but seedling growth rates were also higher for Cistaceae than for Fabaceae individuals. Then, after fire, in terms of biomass, Fabaceae presence decreased from 78.7% to 13.1% while Cistaceae increase from 8% to 83.4%. Given that fire frequency, intensity or severity is partially controlled by the composition and structure of the
Sheppard, B. S.; Goodrich, D. C.; Guertin, D. P.; Burns, I. S.; Canfield, E.; Sidman, G.
New tools and functionality have been incorporated into the Automated Geospatial Watershed Assessment Tool (AGWA) to assess the impacts of wildfire on runoff and erosion. AGWA (see: www.tucson.ars.ag.gov/agwa or http://www.epa.gov/esd/land-sci/agwa/) is a GIS interface jointly developed by the USDA-Agricultural Research Service, the U.S. Environmental Protection Agency, the University of Arizona, and the University of Wyoming to automate the parameterization and execution of a suite of hydrologic and erosion models (RHEM, WEPP, KINEROS2 and SWAT). Through an intuitive interface the user selects an outlet from which AGWA delineates and discretizes the watershed using a Digital Elevation Model (DEM). The watershed model elements are then intersected with terrain, soils, and land cover data layers to derive the requisite model input parameters. With the addition of a burn severity map AGWA can be used to model post wildfire changes to a catchment. By applying the same design storm to burned and unburned conditions a rapid assessment of the watershed can be made and areas that are the most prone to flooding can be identified. Post-fire precipitation and runoff records from gauged forested watersheds are now being used to make improvements to post fire model input parameters. Rainfall and runoff pairs have been selected from these records in order to calibrate parameter values for surface roughness and saturated hydraulic conductivity used in the KINEROS2 model. Several objective functions will be tried in the calibration process. Results will be validated. Currently Department of Interior Burn Area Emergency Response (DOI BAER) teams are using the AGWA-KINEROS2 modeling interface to assess hydrologically imposed risk immediately following wild fire. These parameter refinements are being made to further improve the quality of these assessments.
Chen, F M
Forty-three male mongrel dogs (12.5 +/- 2.5 kg) were divided into normal control (n = 7), immediate infusion (n = 8), non-infusion (n = 13) and delayed infusion (n = 15) groups. A 50% TBSA third degree surface burn was produced by igniting 3% napalm for 30 seconds on the shaved back. Cardiac, pulmonary, hepatic, renal and gastrointestinal functions were monitored following the thermal injury. The findings of these studies showed that mean arterial pressure, cardiac index, left ventricular work, right ventricular work, ADP/O ratio and ATP were all significantly decreased (P less than 0.05). However pulmonary artery wedge pressure, pulmonary vascular resistance, systemic vascular resistance, P(A-a)O2, Beef, Cr, UN, ALT, LDH, TB, DB, and MDA were markedly increased (P less than 0.05). Severe shock occurred soon after burns. Thirteen dogs died within 12 hours in the non-infusion group. All the dogs were resuscitated when immediate infusion of lactic acid Ringers solution was given according to Parkland formula, and all of them tide over shock stage smoothly without obvious changes in visceral functions. However, dogs were not resuscitated when infusion was delayed 6 hours postburn. The changes in visceral were even more severe in this group than those in non-infusion group. These results demonstrated that delayed resuscitation was an important factor of MOF in the early postburn stage. The marked increase in MDA in the myocardiac, lung, liver, renal and gastrointestinal tissues indicated that lipoperoxidation by free oxygen radicals was closely related with visceral damages.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1596785
ROOS RC; JOHNSON AR; CAUDILL JG; RODRIGUEZ JM; WILDE JW
Range fires on the Hanford Site can have a long lasting effect on native plant communities. Wind erosion following removal of protective vegetation from fragile soils compound the damaging effect of fires. Dust storms caused by erosion create health and safety hazards to personnel, and damage facilities and equipment. The Integrated Biological Control Program (IBC) revegetates burned areas to control erosion and consequent dust. Use of native, perennial vegetation in revegetation moves the resulting plant community away from fire-prone annual weeds, and toward the native shrub-steppe that is much less likely to burn in the future. Over the past 10 years, IBC has revegetated major fire areas with good success. IBC staff is monitoring the success of these efforts, and using lessons learned to improve future efforts.
Torre, I.; Díaz, M.
We studied patterns of small mammal abundance and species richness in post-fire habitats by sampling 33 plots (225 m 2 each) representing different stages of vegetation recovery after fire. Small mammal abundance was estimated by live trapping during early spring 1999 and vegetation structure was sampled by visual estimation at the same plots. Recently-burnt areas were characterised by shrubby and herbaceous vegetation with low structural variability, and unburnt areas were characterised by well developed forest cover with high structural complexity. Small mammal abundance and species richness decreased with time elapsed since the last fire (from 5 to at least 50 years), and these differences were associated to the decreasing cover of short shrubs as the post-fire succession of plant communities advanced. However, relationships between vegetation structure and small mammals differed among areas burned in different times, with weak or negative relationship in recently burnt areas and positive and stronger relationship in unburnt areas. Furthermore, the abundance of small mammals was larger than expected from vegetation structure in plots burned recently whereas the contrary pattern was found in unburned areas. We hypothesised that the pattern observed could be related to the responses of small mammal predators to changes in vegetation and landscape structure promoted by fire. Fire-related fragmentation could have promoted the isolation of forest predators (owls and carnivores) in unburned forest patches, a fact that could have produced a higher predation pressure for small mammals. Conversely, small mammal populations would have been enhanced in early post-fire stages by lower predator numbers combined with better predator protection in areas covered by resprouting woody vegetation.
Smith, Hugh; Sheridan, Gary; Lane, Patrick; Nyman, Petter; Haydon, Shane
In many locations fire-prone forest catchments are utilised for the supply of potable water to small communities up to large cities. For example, in south-eastern Australia, wildfires have burned part or all of forest catchments supplying drinking water to Sydney (2001 wildfire), Canberra (2003), Adelaide (2007), Melbourne (2009), as well as various regional towns. Generally, undisturbed forest catchments are a source of high quality water. However, increases in erosion and sediment flux, runoff generation, and changes to the supply of key constituents after wildfire may result in contamination of water supplies. In this review, we present key physical and chemical constituents from a drinking water perspective that may be generated in burned forest catchments and examine post-fire changes to concentrations of these constituents in streams and reservoirs. The World Health Organisation (WHO) drinking water guideline values were used to assess reported post-fire constituent concentrations. Constituents examined include suspended sediment, ash, nutrients, trace metals, anions (Cl-, SO42-), cyanides, and polycyclic aromatic hydrocarbons (PAHs). Constituent concentrations in streams and reservoirs vary substantially following wildfire. In streams, maximum reported total suspended solid concentrations (SSC) in the first year after fire ranged from 11 to 143,000 mg L-1. SSC is often measured in studies of post-fire stream water quality, whereas turbidity is used in drinking water guidelines and more commonly monitored in water supply reservoirs. For burned catchment reservoirs in south-eastern Australia, peak turbidities increased over pre-fire conditions, as did the frequency of exceedance of the turbidity guideline. NO3-, NO2-, and NH4+ may increase after wildfire but maximum recorded concentrations have not exceeded WHO guideline values. Large post-fire increases in total N and total P concentrations in streams and reservoirs have been observed, although there are no
Miller, Mary Ellen
This study examined the potential usefulness of combining remote sensing data with hydrologic models and mapping tools available from Geographic Information Systems (GIS), to evaluate the effects of wildfire. Four subprojects addressed this issue: (1) validation of burn scar maps derived from the Advanced Very High Resolution Radiometer (AVHRR) with the National Fire Occurrence Database; (2) testing the potential of thermal MODIS (Moderate Resolution Imaging Spectroradiometer) data for near-real time burn scar and fire severity mapping; (3) evaluation of Landsat derived burn severity maps within WEPP through the Geo-spatial interface for the Water Erosion Prediction Project (GeoWEPP), and (4) predicting potential post-fire erosion for western U.S. forests utilizing existing datasets and models. Wildfire poses incredibly complex management problems in all of its stages. Today's land managers have the option of trying to mitigate the effects of a severe fire before it occurs by fuel management practices. This process is expensive especially considering the uncertainty of when and where the next fire in a given region will occur. When a wildfire does occur, deciding when to let it burn and when to suppress it may lead to controversial decisions. In addition to the threat to life and property from the fire itself, smoke emissions from large fires can cause air quality problems in distant airsheds. Even after the fire is extinguished, erosion and water quality problems may pose difficult management questions. Contributions stemming from these studies include improved burn scar maps for studying historical fire extent and demonstration of the feasibility of using thermal satellite data to predict burn scar extent when clouds and smoke obscure visible bands. The incorporation of Landsat derived burn severity maps was shown to improve post-fire erosion modeling results. Finally the potential post-fire burn severity and erosion risk maps generated for western US forests
Herndon, David N.; Børsheim, Elisabet; Chao, Tony; Reidy, Paul T.; Borack, Michael S.; Rasmussen, Blake B.; Chondronikola, Maria; Saraf, Manish K.; Sidossis, Labros S.
Elevated metabolic rate is a hallmark of the stress response to severe burn injury. This response is mediated in part by adrenergic stress and is responsive to changes in ambient temperature. We hypothesize that uncoupling of oxidative phosphorylation in skeletal muscle mitochondria contributes to increased metabolic rate in burn survivors. Here, we determined skeletal muscle mitochondrial function in healthy and severely burned adults. Indirect calorimetry was used to estimate metabolic rate in burn patients. Quadriceps muscle biopsies were collected on two separate occasions (11 ± 5 and 21 ± 8 days postinjury) from six severely burned adults (68 ± 19% of total body surface area burned) and 12 healthy adults. Leak, coupled, and uncoupled mitochondrial respiration was determined in permeabilized myofiber bundles. Metabolic rate was significantly greater than predicted values for burn patients at both time points (P < 0.05). Skeletal muscle oxidative capacity, citrate synthase activity, a marker of mitochondrial abundance, and mitochondrial sensitivity to oligomycin were all lower in burn patients vs. controls at both time points (P < 0.05). A greater proportion of maximal mitochondrial respiration was linked to thermogenesis in burn patients compared with controls (P < 0.05). Increased metabolic rate in severely burned adults is accompanied by derangements in skeletal muscle mitochondrial function. Skeletal muscle mitochondria from burn victims are more uncoupled, indicating greater heat production within skeletal muscle. Our findings suggest that skeletal muscle mitochondrial dysfunction contributes to increased metabolic rate in burn victims. PMID:25074988
Porter, Craig; Hardee, Justin; Herndon, David N; Suman, Oscar E
Severe burn trauma results in persistent skeletal muscle catabolism and prolonged immobilization. We hypothesize that structured rehabilitative exercise is a safe and efficacious strategy to restores lean body mass and physical function in burn victims. Here, we review the evidence for the utility of rehabilitative exercise training in restoring physiological function in burn survivors. PMID:25390300
Jeschke, Marc G.; Finnerty, Celeste C.; Emdad, Fatemeh; Rivero, Haidy G.; Kraft, Robert; Williams, Felicia N; Gamelli, Richard L.; Gibran, Nicole S.; Klein, Matthew B.; Arnoldo, Brett D.; Tompkins, Ronald G.; Herndon, David N.
Objective To assess the impact of obesity on morbidity and mortality in severely burned patients. Background Despite the increasing number of people with obesity, little is known about the impact of obesity on postburn outcomes. Methods A total of 405 patients were prospectively enrolled as part of the multicenter trial Inflammation and the Host Response to Injury Glue Grant with the following inclusion criteria: 0 to 89 years of age, admitted within 96 hours after injury, and more than 20% total body surface area burn requiring at least 1 surgical intervention. Body mass index was used in adult patients to stratify according to World Health Organization definitions: less than 18.5 (underweight), 18.5 to 29.9 (normal weight), 30 to 34.9 (obese I), 35 to 39.9 (obese II), and body mass index more than 40 (obese III). Pediatric patients (2 to ≤18 years of age) were stratified by using the Centers for Disease Control and Prevention and World Health Organization body mass index-for-age growth charts to obtain a percentile ranking and then grouped as underweight (<5th percentile), normal weight (5th percentile to <95th percentile), and obese (≥95th percentile). The primary outcome was mortality and secondary outcomes were clinical markers of patient recovery, for example, multiorgan function, infections, sepsis, and length of stay. Results A total of 273 patients had normal weight, 116 were obese, and 16 were underweight; underweight patients were excluded from the analyses because of insufficient patient numbers. There were no differences in primary and secondary outcomes when normal weight patients were compared with obese patients. Further stratification in pediatric and adult patients showed similar results. However, when adult patients were stratified in obesity categories, log-rank analysis showed improved survival in the obese I group and higher mortality in the obese III group compared with obese I group (P < 0.05). Conclusions Overall, obesity was not
Stawski, Clare; Körtner, Gerhard; Nowack, Julia; Geiser, Fritz
Ecosystems can change rapidly and sometimes irreversibly due to a number of anthropogenic and natural factors, such as deforestation and fire. How individual animals exposed to such changes respond behaviourally and physiologically is poorly understood. We quantified the phenotypic plasticity of activity patterns and torpor use - a highly efficient energy conservation mechanism - in brown antechinus (Antechinus stuartii), a small Australian marsupial mammal. We compared groups in densely vegetated forest areas (pre-fire and control) with a group in a burned, open habitat (post-fire). Activity and torpor patterns differed among groups and sexes. Females in the post-fire group spent significantly less time active than the other groups, both during the day and night. However, in males only daytime activity declined in the post-fire group, although overall activity was also reduced on cold days in males for all groups. The reduction in total or diurnal activity in the post-fire group was made energetically possible by a ~3.4-fold and ~2.2-fold increase in the proportion of time females and males, respectively, used torpor in comparison to that in the pre-fire and control groups. Overall, likely due to reproductive needs, torpor was more pronounced in females than in males, but low ambient temperatures increased torpor bout duration in both sexes. Importantly, for both male and female antechinus and likely other small mammals, predator avoidance and energy conservation - achieved by reduced activity and increased torpor use - appear to be vital for post-fire survival where ground cover and refuges have been obliterated. PMID:27001165
Rust, A.; Saxe, S.; Dolan, F.; Hogue, T. S.; McCray, J. E.
Large wildfires are becoming increasingly common in the Western United States. Wildfires that consume greater than twenty percent of the watershed impact river water quality. The surface waters of the arid West are limited and in demand by the aquatic ecosystems, irrigated agriculture, and the region's growing human population. A range of studies, typically focused on individual fires, have observed mobilization of contaminants, nutrients (including nitrates), and sediments into receiving streams. Post-fire metal concentrations have also been observed to increase when fires were located in streams close to urban centers. The objective of this work was to assemble an extensive historical water quality database through data mining from federal, state and local agencies into a fire-database. Data from previous studies on individual fires by the co-authors was also included. The fire-database includes observations of water quality, discharge, geospatial and land characteristics from over 200 fire-impacted watersheds in the western U.S. since 1985. Water quality data from burn impacted watersheds was examined for trends in water quality response using statistical analysis. Watersheds where there was no change in water quality after fire were also examined to determine characteristics of the watershed that make it more resilient to fire. The ultimate goal is to evaluate trends in post-fire water quality response and identify key drivers of resiliency and post-fire response. The fire-database will eventually be publicly available.Large wildfires are becoming increasingly common in the Western United States. Wildfires that consume greater than twenty percent of the watershed impact river water quality. The surface waters of the arid West are limited and in demand by the aquatic ecosystems, irrigated agriculture, and the region's growing human population. A range of studies, typically focused on individual fires, have observed mobilization of contaminants, nutrients
Increasing wildfire size and frequency in the Great Basin call for post-fire grazing management practices that ensure sagebrush steppe communities are productive and resilient to disturbances such as drought and species invasions. We provide guidelines for maintaining productive sagebrush steppe co...
The incidence and mortality of infective endocarditis (IE) in patients with severe burn remain high, which are attributed to invasive procedures, bacteremia, and wound infection after burns. Clinical clues for IE in burns are usually masked by burn-related manifestations, so the diagnosis of IE may be delayed or missed. For burned patients with persistent bacteremia of unknown source, especially Staphylococcus aureus-induced bacteremia, the diagnosis of IE should be considered according to the Duke criteria, and early echocardiography performance is particularly important. Antibiotic therapy is the mainstay initial management, and early surgical intervention is strongly recommended once IE is clearly diagnosed in patients with burns. In order to lower the incidence and mortality of IE in burns, it is very important to take prophylactic procedures along with the whole course of burn management. PMID:26902272
McEntire, Serina J.; Chinkes, David L.; Herndon, David N.; Suman, Oscar E.
Objective We have previously described thermoregulatory responses of severely burned children during submaximal exercise in a thermoneutral environment. However, the thermoregulatory response of burned children to exercise in the heat is not well understood and could have important safety implications for rehabilitation. Study design Children (n=10) with >40% total body surface area burns and non-burned children (n=10) performed a 30 minute bout of treadmill exercise at 75% of their peak aerobic power in a heated environment. Intestinal temperature, burned and unburned skin temperature, and heart rate were recorded pre-exercise, every 2 minutes during exercise, and during recovery. Results Three of the 10 burned children completed the exercise bout in the heat; however, all of the non-burned children completed the 30 minute bout. One burned child reached a core body temperature > 39°C at minute 23. Burned children had a significantly higher core body temperature thru the first 12 minutes of exercise compared to non-burned children. However, 9 of 10 (90%) burned children did not become hyperthermic during exercise in the heat. Conclusion Specific to this study, hyperthermia did not typically occur in burned children, relative to non-burned children. Whether this is due to an intolerance to exercise in the heat or to an inability to generate sufficient heat during exercise needs to be explored further. PMID:20616652
Panov, Alexey; Chi, Xuguang; Winderlich, Jan; Prokushkin, Anatoly; Bryukhanov, Alexander; Korets, Mikhail; Ponomarev, Evgenii; Timokhina, Anastasya; Andreae, Meinrat O.; Heimann, Martin
Calculations of direct emissions of greenhouse gases from boreal wildfires remain uncertain due to problems with emission factors, available carbon, and imprecise estimates of burned areas. Even more varied and sparse are accurate in situ calculations of temporal changes in boreal forest carbon dynamics following fire. Linking simultaneous instrumental atmospheric observations, GIS-based estimates of burned areas, and ecosystem carbon uptake calculations is vital to fill this knowledge gap. Since 2006 the Zotino Tall Tower Observatory (ZOTTO; www.zottoproject.org) a research platform for large-scale climatic observations is operational in Central Siberia (60°48'N, 89°21'E). The data of ongoing greenhouse gases measurements at the tower are used in atmospheric inversions studies to infer the distribution of carbon sinks and sources over central Northern Eurasia. We present our contribution to reducing uncertainties in estimates of fire influence on atmospheric composition and post-fire ecosystem carbon uptake deduced from the large-scale fires that happened in 2012 in the tall tower footprint area. The burned areas were estimated from Landsat ETM 5,8 satellite images, while fires were detected from Terra/Aqua MODIS satellite data. The magnitude of ecological change caused by fires ("burn severity") was measured and mapped with a Normalized Burn Ratio (NBR) index and further calibrated by a complementary field based Composite Burn Index (CBI). Measures of fire radiative power (FRP) index provided information on fire heat release intensity and on the amount and completeness of biomass combustion. Based on the analyzed GIS data, the system of study plots was established in the 5 dominating ecosystem types for a long-term post-fire monitoring. On the plots the comprehensive estimation of ecosystem parameters and carbon pools and their mapping was organized with a laser-based field instrumentation system. The work was supported financially by ISTC Project # 2757p
MacDonald, L.H.; Sampson, R.; Brady, D.; Juarros, L.; Martin, D.
Historic fire suppression efforts have increased the likelihood of large wildfires in much of the western U.S. Post-fire soil erosion and sedimentation risks are important concerns to resource managers. In this paper we develop and apply procedures to predict post-fire erosion and sedimentation risks on a pixel-, catchment-, and landscape-scale in central and western Colorado. Our model for predicting post-fire surface erosion risk is conceptually similar to the Revised Universal Soil Loss Equation (RUSLE). One key addition is the incorporation of a hydrophobicity risk index (HY-RISK) based on vegetation type, predicted fire severity, and soil texture. Post-fire surface erosion risk was assessed for each 90-m pixel by combining HYRISK, slope, soil erodibility, and a factor representing the likely increase in soil wetness due to removal of the vegetation. Sedimentation risk was a simple function of stream gradient. Composite surface erosion and sedimentation risk indices were calculated and compared across the 72 catchments in the study area. When evaluated on a catchment scale, two-thirds of the catchments had relatively little post-fire erosion risk. Steeper catchments with higher fuel loadings typically had the highest post-fire surface erosion risk. These were generally located along the major north-south mountain chains and, to a lesser extent, in west-central Colorado. Sedimentation risks were usually highest in the eastern part of the study area where a higher proportion of streams had lower gradients. While data to validate the predicted erosion and sedimentation risks are lacking, the results appear reasonable and are consistent with our limited field observations. The models and analytic procedures can be readily adapted to other locations and should provide useful tools for planning and management at both the catchment and landscape scale.
Yan, Hong; Mao, Qingxiang; Ma, Yongda; Wang, Li; Chen, Xian; Hu, Yi; Ge, Hengjiang
This study aimed to investigate the endothelial function in a canine model of burn injury combined with seawater immersion. The model of burn injury was established. The dogs were randomly divided into four groups including dogs with burn injury (B group), or burn injury combined with seawater immersion (BI group), or only immersion in seawater (I group), or control animals with no injury or immersion (C group). The circulating endothelial cell (CEC) count and coagulation-fibrinolysis parameters were measured. The CEC count in B group increased at 4 h, 7 h, and 10 h after injury and then reduced, whereas it continuously increased to a greater extent in BI group (P < 0.05). The von Willebrand factor (vWF) activity, plasminogen activator inhibitor (PAI-1), and the ratio of thromboxane B2 (TXB2) to 6-keto-prostaglandin F1α (6-K-PGF1α) in BI group had a marked increase after injury, and the tissue-type plasminogen activator (tPA) in the BI group decreased. Microscope observations revealed thrombus formation in lungs of the animals in BI group, but not in C, I, or B groups. Burn injury causes endothelial dysfunction, and seawater immersion lastingly aggravates this injury, leading to a higher risk of developing thrombosis. PMID:26885523
Wiebringhaus, P; Pierson, T; Menke, H
Thrombosis and pulmonary embolisms are the most common complications in the hospital. The need for anticoagulation during hospital stay is obligatory. Arterial embolisms are rare. They often take place in patients with a pre-existing peripheral artery occlusive disease or in patients with atrial fibrillation. The most common complications in burn patients are wound infection, pneumonia, catheter-associated infections and paralytic ileus. There are almost no data available regarding arterial embolism in burn patients. Therefore we would like to present the case of a 60-year-old woman who was injured by a fire at home and was transported to our special burn unit. She sustained partial thickness burns of both legs and buttocks. The TBSA was 15%. During the first days of clinical stay the patient suffered from a pain induced movement reduction of the left hand. There were no peripheral pulses palpable or by pulsed-wave Doppler detectable. An urgent selected angiography of the left arm was performed and a arterial embolism of the proximal part of the a. brachialis was detected. The patient was operated immediately. After debridement and split-skin graft of the burn wounds the patient was taken to rehabiliation after 35 days. PMID:25564950
Cunningham, J.; Chowanski, Z.; Leffell, M.; Stoker, T.; Lydon, M.; Harmatz, P. Univ. of Massachusetts, Amherst )
The response to injury includes an acute-phase stimulation of plasma ceruloplasmin (CP). Patients recovering from nonburn trauma respond to copper (Cu) supplementation by increasing CP. However, plasma CP has been observed to decrease following moderate to severe burn injury, despite adequate enteral provision of Cu. The authors delivered intravenous Cu via TPN to 10 burned children daily at LOW dose or at HIGH dose during the first 3 weeks of recovery. Plasma CP and total Cu (tot Cu) were measured and nonceruloplasmin' Cu (nonCP-Cu) was calculated assuming 3 ug Cu/mg CP. All patients had low CP (range 6-25 mg/dl, normal = 27-37 mg/dl). The HIGH dose raised both CP and tot Cu without increasing non CP-Cu without increasing nonCp-Cu. CP explained 32% of the tot Cu variance while dose and CP explained 84%. Tot Cu was negatively correlated with % BSA burned. They also observed that this relationship does not hold for burns exceeding 95% BSA. These results are consistent with observations for enteral Cu in burns. They show that CP is responsive to dose in burns and suggest at least 20ug/kg as an appropriate daily Cu dose in TPN for burns.
Few studies attempt to model the range of possible post-fire hydrologic and geomorphic hazards because of the sparseness of data and the coupled, nonlinear, spatial, and temporal relationships among landscape variables. In this study, a type of unsupervised artificial neural network, called a self-organized map (SOM), is trained using data from 540 burned basins in the western United States. The sparsely populated data set includes variables from independent numerical landscape categories (climate, land surface form, geologic texture, and post-fire condition), independent landscape classes (bedrock geology and state), and dependent initiation processes (runoff, landslide, and runoff and landslide combination) and responses (debris flows, floods, and no events). Pattern analysis of the SOM-based component planes is used to identify and interpret relations among the variables. Application of the Davies-Bouldin criteria following k-means clustering of the SOM neurons identified eight conceptual regional models for focusing future research and empirical model development. A split-sample validation on 60 independent basins (not included in the training) indicates that simultaneous predictions of initiation process and response types are at least 78% accurate. As climate shifts from wet to dry conditions, forecasts across the burned landscape reveal a decreasing trend in the total number of debris flow, flood, and runoff events with considerable variability among individual basins. These findings suggest the SOM may be useful in forecasting real-time post-fire hazards, and long-term post-recovery processes and effects of climate change scenarios. ?? 2011.
Wohlgemuth, Peter M.; Hubbert, Ken R.; Robichaud, Peter R.
Wildfire usually promotes flooding and accelerated erosion in upland watersheds. In the summer of 1999, a high-severity wildfire burned a series of mixed pine/oak headwater catchments in the San Jacinto Mountains of southern California. Log erosion barriers (LEBs) were constructed across much of the burned area as an erosion control measure. We built debris basins in two watersheds, each about 1 ha in area, one with LEBs, the other without, to measure post-fire hydrologic response and sediment yield and to evaluate the effectiveness of the LEBs. The watersheds are underlain by granitic bedrock, producing a loamy sand soil above large extents of weathered bedrock and exposed core stones (tors) on the surface. Measured soil water-repellency was similar over the two catchments. Rain gauges measured 348 mm of precipitation in the first post-fire year. The ephemeral stream channels experienced surface flow after major rainstorms, and the source of the water was throughflow exfiltration at the slope/channel interface. Post-fire overland flow produced some rilling, but hillslope erosion measured in silt fences away from any LEBs was minor, as was sediment accumulation behind the LEBs. Stream channels in the catchments exhibited minor net scour. Water yield was much greater in the LEB-treated watershed. This resulted in 14 times more sediment yield by weight than the untreated watershed. Average soil depths determined by augering were nearly double in the catchment without the LEBs compared with the treated watershed. This suggests that differences in water and sediment yield between the two catchments are due to the twofold difference in the estimated soil water-holding capacity in the untreated watershed. It appears that the deeper soils in the untreated watershed were able to retain most of the precipitation, releasing less water to the channels and thereby reducing erosion and sediment yield. Thus, the test of LEB effectiveness was inconclusive in this study, because
Keles, Sultan; Dogusal, Gülçin; Sönmez, Işıl
Autoextraction is one type of self-injurious behaviour. In the literature, self-injurious behaviours are observed in syndromes and genetic conditions. However, to the best of our knowledge, SIB and autoextraction in a severely burned patient have not been reported to date. This report describes the self-inflicted trauma and autoextraction in a severely burned child, and the management of the child during and after burn treatment. PMID:26843993
Finnerty, Celeste C.; Williams, Felicia N.; Kraft, Robert; Suman, Oscar E.; Mlcak, Ronald P.; Herndon, David N.
Background Main contributors to adverse outcomes in severely burned pediatric patients are profound and complex metabolic changes in response to the initial injury. It is currently unknown how long these conditions persist beyond the acute phase post-injury. The aim of the present study was to examine the persistence of abnormalities of various clinical parameters commonly utilized to assess the degree hypermetabolic and inflammatory alterations in severely burned children for up to three years post-burn to identify patient specific therapeutic needs and interventions. Methodology/Principal Findings Patients: Nine-hundred seventy-seven severely burned pediatric patients with burns over 30% of the total body surface admitted to our institution between 1998 and 2008 were enrolled in this study and compared to a cohort non-burned, non-injured children. Demographics and clinical outcomes, hypermetabolism, body composition, organ function, inflammatory and acute phase responses were determined at admission and subsequent regular intervals for up to 36 months post-burn. Statistical analysis was performed using One-way ANOVA, Student's t-test with Bonferroni correction where appropriate with significance accepted at p<0.05. Resting energy expenditure, body composition, metabolic markers, cardiac and organ function clearly demonstrated that burn caused profound alterations for up to three years post-burn demonstrating marked and prolonged hypermetabolism, p<0.05. Along with increased hypermetabolism, significant elevation of cortisol, catecholamines, cytokines, and acute phase proteins indicate that burn patients are in a hyperinflammatory state for up to three years post-burn p<0.05. Conclusions Severe burn injury leads to a much more profound and prolonged hypermetabolic and hyperinflammatory response than previously shown. Given the tremendous adverse events associated with the hypermetabolic and hyperinflamamtory responses, we now identified treatment needs for
Jeschke, Marc G; Finnerty, Celeste C; Kulp, Gabriela A; Kraft, Robert; Herndon, David N
This is a large cohort analysis in severely burned pediatric children to determine whether C-reactive protein (CRP) can be used as a predictor for severe infection or sepsis. Nine-hundred eighteen pediatric burn patients were enrolled in this study. CRP values were measured throughout acute hospitalization and for up to 6 months postburn. Demographic data, incidence of infection, surgical interventions and other relevant clinical information was compiled from medical records. We performed an extensive literature search to identify models that other groups have developed to determine the effects of CRP levels postburn to assess the value of these parameters as predictors of sepsis or severe infection. Statistical analysis was performed using ANOVA and regression analysis where appropriate. Three-hundred fifteen female and 603 male pediatric patients were enrolled in this study. Average total body surface area (TBSA) burn was 45±23%, with full thickness burn over 32±27% TBSA, and patients were 7±6 years old. CRP values significantly correlated with burn size, survival and gender. Significantly higher levels of CRP were found in large burns, in non-survivors, and in females, p<0.05. Using various described models to determine whether CRP levels change before and after an event can predict sepsis or severe infection, we found that CRP cannot predict severe infection or sepsis. Although CRP is a marker of the inflammatory response postburn, CRP fails to predict infection or sepsis in severely burn patients. PMID:23875119
Kasischke, E. S.; Kane, E. S.; Genet, H.; Turetsky, M. R.; ODonnell, J. A.; Hoy, E.; Barrett, K.; Baltzer, J. L.
Recent changes to climate and the fire regime have resulted in a number of distinct changes to patterns of post-fire succession in the boreal forest region of western North America. In interior Alaska and Yukon, these responses include a shift from spruce to deciduous dominated forests in black spruce forests that experienced exposure of mineral soils from deep burning of surface organic soils, as well as low seedling recruitment in white spruce forests as a result of moisture stress. In this presentation, we will use a physical geography framework to analyze factors controlling low seedling recruitment in recently burned black spruce forests in Alaska. This approach allows for understanding how changes in the biologic components of black spruce forest ecosystems (e.g., biogeography) are controlled by factors related to geomorphology and climate over multiple spatial and temporal scales. In particular, this framework will be used to examine how the interactions between fire, climate, topography and soil texture influence pre-fire and post-fire permafrost conditions, which interact to have a strong influence on variations in soil moisture. In turn, recent changes to climate combined with variations in soil moisture controlled by differences in permafrost conditions (ground ice content, active layer thickness) can be used to explain variations in post-fire seedling recruitment in black spruce forests, where low recruitment is occurring on the sites with the driest soils. In addition, we will examine the need for further research in other boreal forest regions of western North America where the presence of pine species (jack and lodgepole) that are absent in Alaska, as well as differences in soils and permafrost conditions, are likely resulting in additional patterns of post-fire succession as a result of recent changes to climate and the fire regime.
Rough, D. T.; MacDonald, L. H.
Daniella T.M. Rough Department of Forest, Rangeland, and Watershed Stewardship, Colorado State University, Fort Collins, CO Lee H. MacDonald Department of Forest, Rangeland, and Watershed Stewardship, Colorado State University, Fort Collins, CO Burned area emergency rehabilitation (BAER) treatments are often applied to reduce post-fire flooding and erosion, but few studies have quantified their efficacy. The effectiveness of different BAER treatments in reducing post-fire erosion rates is being studied for three different wildfires in the Colorado Front Range. The treatments being monitored include seeding, contour felling, mulching, scarification with seeding, and a polyacrylamide (PAM). Sediment production rates are being measured at the hillslope scale using sediment fences installed immediately after the June 2000 Bobcat fire and the 2002 Hayman and Schoonover fires. Neither aerial- nor ground-based seeding significantly reduced erosion rates in the first three years after the Bobcat fire. In contrast, 4.5 t ha-1 of straw mulch consistently reduced sediment yields by more than 90%. Contour felling initially reduced erosion rates for small and moderate storms, but was less effective following the largest storms, presumably due to overwhelmed sediment storage capacity. A paired\\-swale design is being used for the 2002 Hayman and Schoonover fires, as this provides a more sensitive evaluation of BAER treatment effectiveness. The ground-based application of straw mulch and the aerial application of hydromulch each reduced sediment yields by more than 95% in both 2002 and 2003. However, the ground-based application of hydromulch in fall 2002 did not significantly reduce sediment yields in 2003. In 2002 the application of 11 kg ha-1 of PAM in an ammonium sulfate solution reduced sediment yields by 66%. In 2003 neither these sites nor three newly treated sites showed a significant reduction in sediment yields. A dry application of 5.6 kg ha-1 PAM had no detectable
Short, Lauren E.; Gabet, Emmanuel J.; Hoffman, Daniel F.
In 2001, a series of post-fire debris flows brought ~ 30,000 m3 of sediment, deposited as fans, to the narrow valley floor of Sleeping Child Creek in western Montana (USA). In 2005, pebble-counts and surveys of the channel in proximity to six of the debris flow fans documented a regular sequence of fine-grained aggradation upstream of the fans, incision through the fans, and coarse-grained aggradation downstream of the fans. These measurements were repeated in 2012. We found that the delivery of large woody debris (LWD) over the intervening 7 years has been a dominant factor in the disposition of the debris-flow material. The amount of LWD in the study reach has increased by as much as 50% in the areas with a high burn severity, leading to the formation of large logjams that interrupt the flow of sediment along the streambed. Nearly all of the surveyed reaches have aggraded since 2005, including those that had initially begun incising through the debris flow deposits, and the streambed has become generally finer. We hypothesize that, over the next few decades, debris flow sediment not colonized and anchored by riparian vegetation will trickle out of the affected reaches as the logjams slowly degrade.
Shenoy, Aditi; Johnstone, Jill F.; Kasischke, Eric S.; Kielland, Knut
There has been a recent increase in the frequency and extent of wildfires in interior Alaska, and this trend is predicted to continue under a warming climate. Although less well documented, corresponding increases in fire severity are expected. Previous research from boreal forests in Alaska and western Canada indicate that severe fire promotes the recruitment of deciduous tree species and decreases the relative abundance of black spruce (Picea mariana) immediately after fire. Here we extend these observations by (1) examining changes in patterns of aspen and spruce density and biomass that occurred during the first two decades of post-fire succession, and (2) comparing patterns of tree composition in relation to variations in post-fire organic layer depth in four burned black spruce forests in interior Alaska after 10-20 years of succession.Wefound that initial effects of fire severity on recruitment and establishment of aspen and black spruce were maintained by subsequent effects of organic layer depth and initial plant biomass on plant growth during post-fire succession. The proportional contribution of aspen (Populus tremuloides) to total stand biomass remained above 90% during the first and second decades of succession in severely burned sites, while in lightly burned sites the proportional contribution of aspen was reduced due to a 40- fold increase in spruce biomass in these sites. Relationships between organic layer depth and stem density and biomass were consistently negative for aspen, and positive or neutral for black spruce in all four burns. Our results suggest that initial effects of post-fire organic layer depths on deciduous recruitment are likely to translate into a prolonged phase of deciduous dominance during post-fire succession in severely burned stands. This shift in vegetation distribution has important implications for climate-albedo feedbacks, future fire regime, wildlife habitat quality and natural resources for indigenous subsistence
Loller, Cameron; Buxton, Gavin A; Kerzmann, Tony L
Burns caused by hot drinks and soups can be both debilitating and costly, especially to pediatric and geriatric patients. This research is aimed at better understanding the fluid properties that can influence the severity of skin burns. We use a standard model which combines heat transfer and biomedical equations to predict burn severity. In particular, experimental data from a physical model serves as the input to our numerical model to determine the severity of scald burns as a consequence of actual fluid flows. This technique enables us to numerically predict the heat transfer from the hot soup into the skin, without the need to numerically estimate the complex fluid mechanics and thermodynamics of the potentially highly viscous and heterogeneous soup. While the temperature of the soup is obviously is the most important fact in determining the degree of burn, we also find that more viscous fluids result in more severe burns, as the slower flowing thicker fluids remain in contact with the skin for longer. Furthermore, other factors can also increase the severity of burn such as a higher initial fluid temperature, a greater fluid thermal conductivity, or a higher thermal capacity of the fluid. Our combined experimental and numerical investigation finds that for average skin properties a very viscous fluid at 100°C, the fluid must be in contact with the skin for around 15-20s to cause second degree burns, and more than 80s to cause a third degree burn. PMID:26796241
... doing so puts you in danger as well. Chemical and Electrical Burns For chemical and electrical burns, call 911 or your local ... the power source has been turned off. For chemical burns: Dry chemicals should be brushed off the ...
Kotliar, Natasha B.; Haire, Sandra L.; Key, Carl H.
We evaluate burn-severity patterns for six burns that occurred in the southern Rocky Mountains and the Colorado Plateau in 2000. We compare the results of two data sources: Burned Area Rehabilitations Teams (BAER) and a spatial burnseverity model derived from satellite imagery (the Normalized Burn Ratio; NBR). BAER maps tended to overestimate area of severe burns and underestimate area of moderate-severity burns relative to NBR maps. Low elevation and more southern ponderosa pine burns were predominantly understory burns, whereas burns at higher elevations and farther north had a greater component of high-severity burns. Thus, much, if not most, of the area covered by these burns appears to be consistent with historic burns and contributes to healthy functioning ecosystems.
Pennington, J Daniel; Wall, Anji E; Schlesinger, Joseph J; Higdon, Kent K; Weavind, Liza
Cryoamputation, or physiologic amputation, is a well-described procedure typically used to amputate gangrenous lower extremities. In such cases the patient is too unstable for transport to the operating room, so cryoamputation using dry ice or other refrigerant allows for immediate bedside intervention and later operative amputation when the patient is more stable. In this study the authors describe the use of cryoamputation to stabilize a burn patient with a nonviable upper extremity considered to be contributing significantly to his metabolic acidosis. This experience suggests that cryoamputation may be a reasonable technique to consider when a burn patient presents with a nonviable extremity but is too unstable for immediate operative amputation. PMID:24978024
Kollias, S; Stampolidis, N; Kourakos, P; Mantzari, E; Koupidis, S; Tsaousi, S; Dimitrouli, A; Atiyeh, B; Castana, O
Abdominal compartment syndrome (ACS) occurs when increasing intra abdominal-pressure (IAP) reduces blood flow to abdominal organs. This results in impairment of pulmonary, cardiovascular, renal, hepatic, central nervous system and gastro-intestinal (gi) function, causing multiple organ dysfunction syndrome and death. The significant prognostic value of elevated intra-abdominal pressure has prompted many intensive care units to adopt measurement of this physiologic parameter as a routine vital sign in patients at risk. ACS generally occurs in patients who are critically ill due to any of a wide variety of medical and surgical conditions. it has been recently described as a rare complication of burn injury. it is fundamental to: 1) recognize IAP and ACS; 2) resuscitate effectively; and 3) prevent the development IAP-induced end-organ dysfunction and failure. We present our recent experience with one patient suffering from ACS secondary to burn injury and the physiologic results of abdominal wall escharotomy. PMID:26668555
kollias, S.; Stampolidis, N.; kourakos, P.; Mantzari, E.; Koupidis, S.; Tsaousi, S.; Dimitrouli, A.; Atiyeh, B.; Castana, O.
Summary Abdominal compartment syndrome (ACS) occurs when increasing intra abdominal-pressure (IAP) reduces blood flow to abdominal organs. This results in impairment of pulmonary, cardiovascular, renal, hepatic, central nervous system and gastro-intestinal (gi) function, causing multiple organ dysfunction syndrome and death. The significant prognostic value of elevated intra-abdominal pressure has prompted many intensive care units to adopt measurement of this physiologic parameter as a routine vital sign in patients at risk. ACS generally occurs in patients who are critically ill due to any of a wide variety of medical and surgical conditions. it has been recently described as a rare complication of burn injury. it is fundamental to: 1) recognize IAP and ACS; 2) resuscitate effectively; and 3) prevent the development IAP-induced end-organ dysfunction and failure. We present our recent experience with one patient suffering from ACS secondary to burn injury and the physiologic results of abdominal wall escharotomy. PMID:26668555
Birch, Donovan Shayne
This work consisted of two studies of burn severity using infrared perimeter maps and satellite-inferred burn severity data, differenced Normalized Burn Ratio, from 42 wildland fires from central Idaho and western Montana from 2005 to 2007, and 2011. Study 1 examined the proportion of burn severity categories for individual daily areas burned. We defined 2,697 areas, from which we calculated the proportion of three burn severity classes. The proportion of high severity was weakly correlated with size of area burned. Large areas burned do not consistently produced larger proportions of high severity. Study 2 analyzed burn severity relative to 20 environmental variables using the Random Forest machine learning algorithm. We used ten daily weather observations, eight 34-yr climate percentiles, seven topographical index measurements, and four vegetation characteristics from 10,819 randomly located points. We found that higher percentage existing vegetation cover had larger influences on changes in burn severity.
Balzar, E; Strigl, E; Wiedermann, V; Khoss, A; Meissl, G
A marked increase in the rate of admission of children with burns and scalding has been observed since 1977 at the Paediatric Hospital of Vienna University. The average age of 94 patients admitted between 1982 and 1986 was 2.2 +/- 2.1 years. An analysis of the age group 1 to 2 years revealed that burns with an extent of up to 10% of the body surface were seen in 18% of patients, up to a body surface of 20% in 18%, and more than 30% of the body surface in 5.3%. Among the entire group of 94 patients 32.9% had burns of up to 10% of the body surface, 41.4% of up to 20%. Written information as to primary care at the place of injury or in the nearest hospital was obtainable in only 35 out of 94 patients (38%). 21.1% of all patients had a raised temperature on the day of admission to this hospital as a consequence of a negative fluid balance. However, only 4 patients (4.2%) out of the 94 were transferred because of fever and/or septicaemia. Guidelines are proposed as to primary care at the site of trauma and during transport to hospital on the basis of a survey of the literature. PMID:3055686
Wimberly, M. C.; Cochrane, M. A.; Baer, A. D.; Zhu, Z.
Fire severity datasets derived from satellite remote sensing data are now being used extensively in wildfire research and land management. Maps of burn severity based on the differenced normalized burn ratio (dNBR) are being produced and disseminated by the Monitoring Trends in Burn Severity (MTBS) project for all major wildfires in the United States from 1984 to present. This abundance of data presents unprecedented new opportunities for understanding how weather, terrain, and fuels interact to determine fire severity patterns, and for testing the effectiveness of fuel-reduction strategies for mitigating wildfire impacts. However, these datasets present challenges for statistical analysis because of their large sizes and the non-independence of spatially autocorrelated pixels. To explore the importance of spatial autocorrelation, we analyzed the spatial patterns of burn severity in two recent wildfires - the 2004 School Fire in the Blue Mountains of southeastern Washington and the 2005 Warm Fire on the Kaibab Plateau in northern Arizona. Conditional autoregressive (CAR) models were fitted with dNBR as the dependent variable and topography, fuels, and locations of recent fuel treatments as the independent variables. In both fires, elevation, slope, and aspect had strong effects on burn severity. Fuels had stronger effects on burn severity for the School fire than for the Warm Fire. In both fires, fuel treatments that combined thinning and prescribed burning resulted in statistically significant reductions in fire severity. The CAR models were then decomposed to isolate the spatial signal, which reflected spatially structured variability in dNBR that was not related to the independent variables. The spatial signals were correlated with the burn progression maps, reflecting spatial and temporal variability in weather and fire behavior (e.g. wind versus plume driven) over the course of the fire. These results suggest that spatial autocorrelation in the analysis of
Prichard, Susan J; Kennedy, Maureen C
Under a rapidly warming climate, a critical management issue in semiarid forests of western North America is how to increase forest resilience to wildfire. We evaluated relationships between fuel reduction treatments and burn severity in the 2006 Tripod Complex fires, which burned over 70,000 ha of mixed-conifer forests in the North Cascades range of Washington State and involved 387 past harvest and fuel treatment units. A secondary objective was to investigate other drivers of burn severity including landform, weather, vegetation characteristics, and a recent mountain pine beetle outbreak. We used sequential autoregression (SAR) to evaluate drivers of burn severity, represented by the relative differenced Normalized Burn Ratio index, in two study areas that are centered on early progressions of the wildfire complex. Significant predictor variables include treatment type, landform (elevation), fire weather (minimum relative humidity and maximum temperature), and vegetation characteristics, including canopy closure, cover type, and mountain pine beetle attack. Recent mountain pine beetle damage was a statistically significant predictor variable with red and mixed classes of beetle attack associated with higher burn severity. Treatment age and size were only weakly correlated with burn severity and may be partly explained by the lack of treatments older than 30 years and the low rates of fuel succession in these semiarid forests. Even during extreme weather, fuel conditions and landform strongly influenced patterns of burn severity. Fuel treatments that included recent prescribed burning of surface fuels were particularly effective at mitigating burn severity. Although surface and canopy fuel treatments are unlikely to substantially reduce the area burned in regional fire years, recent research, including this study, suggests that they can be an effective management strategy for increasing forest landscape resilience to wildfires. PMID:24834742
Elliott, J.G.; Smith, M.E.; Friedel, M.J.; Stevens, M.R.; Bossong, C.R.; Litke, D.W.; Parker, R.S.; Costello, C.; Wagner, J.; Char, S.J.; Bauer, M.A.; Wilds, S.R.
Wildfires caused extreme changes in the hydrologic, hydraulic, and geomorphologic characteristics of many Colorado drainage basins in the summer of 2002. Detailed assessments were made of the short-term effects of three wildfires on burned and adjacent unburned parts of drainage basins. These were the Hayman, Coal Seam, and Missionary Ridge wildfires. Longer term runoff characteristics that reflect post-fire drainage basin recovery expected to develop over a period of several years also were analyzed for two affected stream reaches: the South Platte River between Deckers and Trumbull, and Mitchell Creek in Glenwood Springs. The 10-, 50-, 100-, and 500-year flood-plain boundaries and water-surface profiles were computed in a detailed hydraulic study of the Deckers-to-Trumbull reach. The Hayman wildfire burned approximately 138,000 acres (216 square miles) in granitic terrain near Denver, and the predominant potential hazard in this area is flooding by sediment-laden water along the large tributaries to and the main stem of the South Platte River. The Coal Seam wildfire burned approximately 12,200 acres (19.1 square miles) near Glenwood Springs, and the Missionary Ridge wildfire burned approximately 70,500 acres (110 square miles) near Durango, both in areas underlain by marine shales where the predominant potential hazard is debris-flow inundation of low-lying areas. Hydrographs and peak discharges for pre-burn and post-burn scenarios were computed for each drainage basin and tributary subbasin by using rainfall-runoff models because streamflow data for most tributary subbasins were not available. An objective rainfall-runoff model calibration method based on nonlinear regression and referred to as the ?objective calibration method? was developed and applied to rainfall-runoff models for three burned areas. The HEC-1 rainfall-runoff model was used to simulate the pre-burn rainfall-runoff processes in response to the 100-year storm, and HEC-HMS was used for runoff
Papathanasiou, C.; Makropoulos, C.; Mimikou, M.
Floods and forest fires are two of the most devastating natural hazards with severe socioeconomic, environmental as well as aesthetic impacts on the affected areas. Traditionally, these hazards are examined from different perspectives and are thus investigated through different, independent systems, overlooking the fact that they are tightly interrelated phenomena. In fact, the same flood event is more severe, i.e. associated with increased runoff discharge and peak flow and decreased time to peak, if it occurs over a burnt area than that occurring over a land not affected by fire. Mediterranean periurban areas, where forests covered with flammable vegetation coexist with agricultural land and urban zones, are typical areas particularly prone to the combined impact of floods and forest fires. Hence, the accurate assessment and effective management of post-fire flood risk becomes an issue of priority. The research presented in this paper aims to develop a robust methodological framework, using state of art tools and modern technologies to support the estimation of the change in time of five representative hydrological parameters for post-fire conditions. The proposed methodology considers both longer- and short-term initial conditions in order to assess the dynamic evolution of the selected parameters. The research focuses on typical Mediterranean periurban areas that are subjected to both hazards and concludes with a set of equations that associate post-fire and pre-fire conditions for five Fire Severity (FS) classes and three soil moisture states. The methodology has been tested for several flood events on the Rafina catchment, a periurban catchment in Eastern Attica (Greece). In order to validate the methodology, simulated hydrographs were produced and compared against available observed data. Results indicate a close convergence of observed and simulated flows. The proposed methodology is particularly flexible and thus easily adaptable to catchments with similar
Baer, L.A.; Wu, X.; Tou, J. C.; Johnson, E.; Wolf, S.E.; Wade, C.E.
Burn and disuse results in metabolic and bone changes associated with substantial and sustained bone loss. Such loss can lead to an increased fracture incidence and osteopenia. We studied the independent effects of burn and disuse on bone morphology, composition and strength, and microstructure of the bone alterations 14 days after injury. Sprague-Dawley rats were randomized into four groups: Sham/Ambulatory (SA), Burn/Ambulatory (BA), Sham/Hindlimb Unloaded (SH) and Burn/Hindlimb Unloaded (BH). Burn groups received a 40% total body surface area full-thickness scald burn. Disuse by hindlimb unloading was initiated immediately following injury. Bone turnover was determined in plasma and urine. Femur biomechanical parameters were measured by three-point bending tests and bone microarchitecture was determined by microcomputed tomography (uCT). On day 14, a significant reduction in body mass was observed as a result of burn, disuse and a combination of both. In terms of bone health, disuse alone and in combination affected femur weight, length and bone mineral content. Bending failure energy, an index of femur strength, was significantly reduced in all groups and maximum bending stress was lower when burn and disuse were combined. Osteocalcin was reduced in BA compared to the other groups, indicating influence of burn. The reductions observed in femur weight, BMC, biomechanical parameters and indices of bone formation are primarily responses to the combination of burn and disuse. These results offer insight into bone degradation following severe injury and disuse. PMID:23142361
Marañón Jiménez, Sara; Castro, J.; Kowalski, A.; Serrano-Ortiz, P.; Ruiz, B.; Sancez-Canete, Ep; Zamora, R.
Wildfires are the main cause of forests and understory destruction in Mediterranean areas. One of the most dramatic consequences is the perturbation of carbon fluxes. A high percentage of the CO2 emitted by the ecosystem after a wildfire is due to soil respiration, which represents the most important uncertainty in the global carbon cycle. In this study we have quantified the soil respiration and its seasonal variability in reforested pine forests in the National and Natural Park of Sierra Nevada which were burned in September of 2005. Measurement campaigns were carried out along two years in two experimental plots at different altitudinal levels (1500 and 2200 m a.s.l.), in which three post-fire silvicultural treatments of burned wood were established: 1) "Non-Intervention" (NI), leaving all of the burnt trees standing. 2) "Cut plus Lopping" (CL), a treatment where most of the trees were cut and felled, with the main branches also lopped off, but leaving all the cut biomass in situ covering partially the ground surface 3) "Salvage Logging" (SL), all trees were cut and the trunks and branches were removed. Soil respiration was highly determined by the effects derived of the altitudinal level, with the highest values at the lowest altitude. The seasonal precipitation regime had also a key role. Soil respiration kept a basal level during the summer drought, during this period the response to the altitudinal level and post-fire treatments were reduced. On the other hand, soil respiration boosted after rain events, when the differences between treatments became more pronounced. In general, especially under these conditions of absence of water limitation, the post-fire burnt wood treatment with the highest CO2 fluxes was that in which all the burnt wood biomass remained covering partially the soil surface ("Cut plus Lopping") while the lowest values were registered in the treatment in which the soil was bared ("Salvage Logging"). Results of this study are especially
Smithwick, Erica A. H.; Naithani, Kusum J.; Balser, Teri C.; Romme, William H.; Turner, Monica G.
Stand-replacing fires influence soil nitrogen availability and microbial community composition, which may in turn mediate post-fire successional dynamics and nutrient cycling. However, fires create patchiness at both local and landscape scales and do not result in consistent patterns of ecological dynamics. The objectives of this study were to (1) quantify the spatial structure of microbial communities in forest stands recently affected by stand-replacing fire and (2) determine whether microbial variables aid predictions of in situ net nitrogen mineralization rates in recently burned stands. The study was conducted in lodgepole pine (Pinus contorta var. latifolia) and Engelmann spruce/subalpine fir (Picea engelmannii/Abies lasiocarpa) forest stands that burned during summer 2000 in Greater Yellowstone (Wyoming, USA). Using a fully probabilistic spatial process model and Bayesian kriging, the spatial structure of microbial lipid abundance and fungi-to-bacteria ratios were found to be spatially structured within plots two years following fire (for most plots, autocorrelation range varied from 1.5 to 10.5 m). Congruence of spatial patterns among microbial variables, in situ net N mineralization, and cover variables was evident. Stepwise regression resulted in significant models of in situ net N mineralization and included variables describing fungal and bacterial abundance, although explained variance was low (R2<0.29). Unraveling complex spatial patterns of nutrient cycling and the biotic factors that regulate it remains challenging but is critical for explaining post-fire ecosystem function, especially in Greater Yellowstone, which is projected to experience increased fire frequencies by mid 21st Century. PMID:23226324
Smithwick, Erica A H; Naithani, Kusum J; Balser, Teri C; Romme, William H; Turner, Monica G
Stand-replacing fires influence soil nitrogen availability and microbial community composition, which may in turn mediate post-fire successional dynamics and nutrient cycling. However, fires create patchiness at both local and landscape scales and do not result in consistent patterns of ecological dynamics. The objectives of this study were to (1) quantify the spatial structure of microbial communities in forest stands recently affected by stand-replacing fire and (2) determine whether microbial variables aid predictions of in situ net nitrogen mineralization rates in recently burned stands. The study was conducted in lodgepole pine (Pinus contorta var. latifolia) and Engelmann spruce/subalpine fir (Picea engelmannii/Abies lasiocarpa) forest stands that burned during summer 2000 in Greater Yellowstone (Wyoming, USA). Using a fully probabilistic spatial process model and Bayesian kriging, the spatial structure of microbial lipid abundance and fungi-to-bacteria ratios were found to be spatially structured within plots two years following fire (for most plots, autocorrelation range varied from 1.5 to 10.5 m). Congruence of spatial patterns among microbial variables, in situ net N mineralization, and cover variables was evident. Stepwise regression resulted in significant models of in situ net N mineralization and included variables describing fungal and bacterial abundance, although explained variance was low (R²<0.29). Unraveling complex spatial patterns of nutrient cycling and the biotic factors that regulate it remains challenging but is critical for explaining post-fire ecosystem function, especially in Greater Yellowstone, which is projected to experience increased fire frequencies by mid 21(st) Century. PMID:23226324
Hedo, J.; Lucas-Borja, M. E.; Wic, C.; Andrés Abellán, M.; de Las Heras, J.
Wildfires affecting forest ecosystems and post-fire silvicultural treatments may cause considerable changes in soil properties. The capacity of different microbial groups to recolonize soil after disturbances is crucial for proper soil functioning. The aim of this work was to investigate some microbial soil properties and enzyme activities in semiarid and dry Aleppo pine (Pinus halepensis M.) forest stands. Different plots affected by a wildfire event 17 years ago without or with post-fire silvicultural treatments five years after the fire event were selected. A mature Aleppo pine stand unaffected by wildfire and not thinned was used as a control. Physicochemical soil properties (soil texture, pH, carbonates, organic matter, electrical conductivity, total N and P), soil enzymes (urease, phosphatase, β-glucosidase and dehydrogenase activities), soil respiration and soil microbial biomass carbon were analysed in the selected forests areas and plots. The main finding was that long time after this fire event produces no differences in the microbiological soil properties and enzyme activities of soil after comparing burned and thinned, burned and not thinned, and mature plots. Thus, the long-term consequences and post-fire silvicultural management in the form of thinning have a significant effect on the site recovery after fire. Moreover, significant site variation was generally seen in soil enzyme activities and microbiological parameters. We conclude that total vegetation restoration normalises microbial parameters, and that wildfire and post-fire silvicultural treatments are not significant factors of soil properties after 17 years.
Hedo, J.; Lucas-Borja, M. E.; Wic, C.; Andrés-Abellán, M.; de Las Heras, J.
Wildfires affecting forest ecosystems and post-fire silvicultural treatments may cause considerable changes in soil properties. The capacity of different microbial groups to recolonise soil after disturbances is crucial for proper soil functioning. The aim of this work was to investigate some microbial soil properties and enzyme activities in semiarid and dry Aleppo pine (Pinus halepensis M.) forest stands. Different plots affected by a wildfire event 17 years ago without or with post-fire silvicultural treatments 5 years after the fire event were selected. A mature Aleppo pine stand, unaffected by wildfire and not thinned was used as a control. Physicochemical soil properties (soil texture, pH, carbonates, organic matter, electrical conductivity, total N and P), soil enzymes (urease, phosphatase, β-glucosidase and dehydrogenase activities), soil respiration and soil microbial biomass carbon were analysed in the selected forests areas and plots. The main finding was that long time after this fire event produces no differences in the microbiological soil properties and enzyme activities of soil after comparing burned and thinned, burned and not thinned, and mature plots. Moreover, significant site variation was generally seen in soil enzyme activities and microbiological parameters. We conclude that total vegetation recovery normalises post-fire soil microbial parameters, and that wildfire and post-fire silvicultural treatments are not significant factors affecting soil properties after 17 years.
Jeng, James C; Jaskille, Amin D; Lunsford, Patricia M; Jordan, Marion H
Improved markers of resuscitation are needed in patients with severe burn injuries. In previous animal and human work, we showed 1) wound hypoperfusion plays a role in burn depth progression, 2) that there are periods of repetitive ischemia and reperfusion which correlate closely to wound hypoperfusion, and 3) that wound and splanchnic bed CO2 measurements are dependent on the adequacy of resuscitation. We and others believe that current markers for resuscitation, urine output (U/O), and mean arterial pressure (MAP), lag behind in reflecting wound perfusion. In this study, we explore whether gastric and tissue tonometry are better in reflecting minute-to-minute changes in wound perfusion in humans. During the 48-hour experimental period, burn wound, gastric, and arterial pH, Pco2, and PaO2 were measured every 6 seconds using a Paratrend 7 monitor in four patients with life threatening burns. Slopes of change were analyzed and a proportion derived relative to pooled data on 5-minute intervals. Serum lactate, U/O, and MAP were recorded. Laser Doppler Imager (LDI) scans were performed on burn areas every 4 hours, allowing real-time determination of burn perfusion. Resuscitation followed current clinical guidelines. All four patients eventually succumbed, one doing so during the observation period. In the remaining three, U/O and MAP goals were met within 2 hours of resuscitation. Our analysis shows cyclic changes in burn wound pH, CO2, and PaO2, gastric CO2, and PaO2, and arterial base deficit (all P < .005). LDI showed cyclic changes in perfusion (P < .0001) which closely mimic the changes in wound pH, gastric CO2, and arterial base deficit. These changes preceded changes in U/O, MAP, and lactate. Although U/O, MAP, and serum lactate reflect changes in burn wound perfusion, they lag behind other markers. Tissue pH and CO2 and gastric CO2 seem to be more timely related to changes in actual burn perfusion. PMID:18182897
Woods, S. W.; Balfour, V.
Consumption of the litter and duff layers in forest wildfires can lead to substantial increases in the frequency and magnitude of overland flow. These increases result from the loss of storage in the organic surface layer, reduced surface roughness, and from sealing of the exposed mineral soil surface. The presence of an ash layer may accentuate surface sealing by providing an additional source of fine material, or it may reduce runoff by storing rainfall and by protecting the soil surface from raindrop impacts. We used simulated rainfall experiments to assess the effects of litter and duff consumption and the presence of ash layers of varying thickness on post fire runoff at two forested sites in western Montana, one with sandy loam soils formed out of granodiorite and the other with gravelly silt loam soils formed out of argillite. At each site we measured the runoff from simulated rainfall in replicated 0.5 m2 plots before and after application of the following treatments: 1) burning with a fuel load of 90 Mg ha-1, 2) manual removal of the litter and duff layers, 3) addition of 0.5, 2.5 and 5 cm of ash to plots from which the litter and duff had previously been removed, and 4) addition of the same depths of ash to burned plots at the sandy loam site. In the burned plots the surface litter and duff layers were completely consumed and a <1cm layer of black and gray ash and char was formed, indicating a moderate severity burn. The mean soil temperature in the upper 1 cm of the mineral soil was 70° C, and there was no detectable increase in water repellency. The mean final infiltration capacity of the burned sandy loam plots was 35 mm hr-1 compared to a pre-fire mean of 87 mm hr-1, while in the gravelly silt loam plots the pre- and post burn infiltration capacities (27 and 31 mm hr- 1) were not significantly different. Manual removal of the litter and duff layers reduced the mean final infiltration capacity in the sandy loam plots from 64 mm hr-1 to 40 mm hr-1 and
Medved, Fabian; Medesan, Raluca; Rothenberger, Jens Martin; Schaller, Hans-Eberhard; Schoeller, Thomas; Manoli, Theodora; Weitgasser, Lennart; Naumann, Aline; Weitgasser, Laurenz
Reconstruction of soft tissue defects of the ear with burns remains one of the most difficult tasks for the reconstructive surgeon. Although numerous reconstructive options are available, the results are often unpredictable and worse than expected. Besides full and split skin grafting, local random pattern flaps and pedicled flaps are frequently utilized to cover soft tissue defects of the outer auricle. Because of the difficulty and unpredictable nature of outer ear reconstruction after burn injury, a case-control study was conducted to determine the best reconstructive approach. The microcirculatory properties of different types of soft tissue reconstruction of the outer ear with burns in six severely burned Caucasian patients (three men and three women; mean age, 46 years (range, 22-70)) were compared to those in the healthy tissue of the outer ear using the O2C device (Oxygen to See; LEA Medizintechnik, Gießen, Germany). The results of this study revealed that the investigated microcirculation parameters such as the median values of blood flow (control group: 126 AU), relative amount of hemoglobin (control group: 59.5 AU), and tissue oxygen saturation (control group: 73%) are most similar to those of normal ear tissue when pedicled flaps based on the superficial temporal artery were used. These findings suggest that this type of reconstruction is superior for soft tissue reconstruction of the outer ear with burns in contrast to random pattern flaps and full skin grafts regarding the microcirculatory aspects. These findings may improve the knowledge on soft tissue viability and facilitate the exceptional and delicate process of planning the reconstruction of the auricle with burns. PMID:26997326
Saraf, Manish Kumar; Herndon, David N; Porter, Craig; Toliver-Kinsky, Tracy; Radhakrishnan, Ravi; Chao, Tony; Chondronikola, Maria; Sidossis, Labros S
Severe burn injury produces a plethora of metabolic abnormalities which contribute to the prolonged morbidity of burn survivors. The authors have recently demonstrated trans-differentiation of white adipose tissue (WAT) after burn trauma, toward a more thermogenic phenotype. However, the impact of burn injury on subcutaneous WAT (sWAT) morphology in humans is unknown. Here, the authors studied the effect of severe burn injury on the architecture of sWAT. sWAT was collected from 11 severely burned children (11 ± 3 years; 55 ± 16% total BSA burned) and 12 nonburned healthy children (9 ± 3 years). Histology, electron microscopy, immunohistochemistry, and immunofluorescence were performed on fixed adipose tissue sections. sWAT cytokine and collagen concentrations were measured by multiplex assay and sirius/fast green staining method, respectively. sWAT histology demonstrated multiple fat droplets, significantly (P < .05) reduced mean cell size (104 ± 6 vs 68 ± 3 μm) and higher collagen content (7 ± 0.8 vs 4 ± 0.4) in burn patients. sWAT from burn victims stained positive for CD68 suggesting infiltration of macrophages. Furthermore, electron microscopic analysis showed multiple fat droplets and greater mitochondrial abundance in sWAT of burn survivors. In agreement with this, mitochondrial respiratory capacity in the leak and coupled state increased by 100% in sWAT of burned children from 1 to 3 weeks postinjury. The cytokines IL-6, IL-8, IL-13, IL-1a, IL-1b, MCP-1, and TNF-α were all significantly greater in the sWAT of burned children versus healthy children (P < .05). Furthermore, IL-6, IL-8, IL1-a, IL-1b, and TNF-α significantly increased after injury in sWAT of burned children (P < .05). This study provides detailed evidence of morphological and functional changes in sWAT of burn survivors which was associated with tissue inflammation. A better understanding of morphological and functional changes in sWAT will help discern the mechanisms underlying
Sheridan, Gary; Langhans, Christoph; Nyman, Petter; Lane, Patrick
Three decades of data show that annual average post-fire erosion rates vary within se Australian forested landscapes over ca. 4 orders of magnitude from <0.01 t ha-1 y-1 to 100 t ha-1 y-1. These differences are currently difficult to predict, and here we propose and explore a new conceptual framework that may assist in post-fire erosion prediction. The dominant erosion processes are observed to depend on infiltration-excess overland flow, and large increases in erosion rates are broadly associated with shifts or "jumps" across erosion process-thresholds. Additional higher- yielding processes are added hierarchically with increased rainfall forcing, starting with raindrop splash, to interill, to rill, to hillslope debris flows, and finally to channel debris flows. In this conceptual framework, the first-order control on the erosion rate results from the combination of system properties and forcing that enables additional erosion processes to be activated in the hierarchy. Second-order controls are process-specific, and explain the remaining variability in erosion rates within each of the processes for a given forcing. Large erosion increases are related to the way in which soil properties, fire severity, hillslope gradient, and channel gradient trigger "jumps" across these process thresholds, which, it is argued, explain the majority of the variability in post-fire erosion rates at headwater catchment scales. The applicability and usefulness of this conceptual framework to erosion prediction in a range of fire affected environments (eg. Western US, Canada, the Mediterranean) will be explored.
Muschitz, Gabriela Katharina; Schwabegger, Elisabeth; Kocijan, Roland; Baierl, Andreas; Moussalli, Hervé; Fochtmann, Alexandra; Nickl, Stefanie; Tinhofer, Ines; Haschka, Judith; Resch, Heinrich; Rath, Thomas; Pietschmann, Peter; Muschitz, Christian
This study investigated serum burnover marker in male patients after severe burn injury. Ongoing changes suggest alterations in bone metabolism with a likely adverse influence on bone quality and structure. PMID:26789778
Hobbie, John; Rocha, Adrian; Shaver, Gaius
This is the AmeriFlux version of the carbon flux data for the site US-An1 Anaktuvuk River Severe Burn. Site Description - The Anaktuvuk River fire on the North Slope of Alaska started on July 16, 2007 by lightning. It continued until the end of September when nearby lakes had already frozen over and burned >256,000 acres, creating a mosaic of patches that differed in burn severity. The Anaktuvuk River Severe Burn, Moderate Burn, and Unburned sites are 40 km to the west of the nearest road and were selected in late May 2008 to determine the effects of the fire on carbon, water, and energy exchanges during the growing season. Because the fire had burned through September of the previous year, initial deployment of flux towers occurred prior to any significant vegetative regrowth, and our sampling campaign captured the full growing season in 2008. The Severe Burn site consisted of a large area in which all of the green vegetation were consumed in the fire and some of the organic matter had burnt to the mineral soil in many places. A bear damaged the tower during the last week of August 2008, and it was repaired shortly after.
Huang, Y S
A series of studies demonstrated that myocardial damage and cardiac dysfunction occurs immediately following severe burn, even before significant reduction in blood volume due to increased capillary permeability. Such myocardial damage and cardiac dysfunction leads to cardiac deficiency, and it is a precipitating factor for burn shock and ischemic/hypoxic injury. In recent years, many experimental and clinical studies elucidated the pathogenesis and confirmed the clinical importance of prevention and treatment of"shock heart"in the early stage post severe burn. PMID:27188482
Turner, M.G.; Gardner, R.H.; Hargrove, W.W. ); Romme, W.H. )
The 1988 Yellowstone fires provided a unique opportunity to examine how the geometry of fire-created patches affects plant reestablishment. We initiated studies in 1990 in small (1 ha), moderated (74-200 ha), and large (480-3698 ha) crown-fire patches in each of 3 areas. Lodgepole pine forest is reestablishing in most burned areas, but seedling density varies by two orders of magnitude. At spatial scales <100 m, lodgepole seedling density declines with distance from the patch edge. Resprouting of herbaceous vegetation led to prompt revegetation in burned patches of all sizes, suggesting within-patch survival is a dominant recovery mechanism for grasses, forbs, and shrubs. Some annuals (e.g., Gayophytum diffusum) achieved greater densities in large vs. small crown-fire patches and colonized large patches more rapidly. Post-fire plant reestablishment in Yellowstone appears rapid and autogenic even in large burns, and the relative importance of factors controlling early postfire succession varies with spatial scale.
The Algerian forests are characterized by a particularly flammable material and fuel. The wind, the relief and the slope facilitates the propagation of fire. The use of remote sensing data multi-dates, combined with other types of data of various kinds on the environment and forest burned, opens up interesting perspectives for the management of post-fire regeneration. In this study the use of multi-temporal remote sensing image Alsat-1 and Landsat combined with other types of data concerning both background and burned down forest appears to be promising in evaluating and spatial and temporal effects of post fire regeneration. A spatial analysis taking into consideration the characteristics of the burned down site in the North West of Algeria, allowed to better account new factors to explain the regeneration and its temporal and spatial variation. We intended to show the potential use of remote sensing data from satellite ALSAT-1, of spatial resolution of 32 m. . This approach allows showing the contribution of the data of Algerian satellite ALSAT in the detection and the well attended some forest fires in Algeria.
Kaya, S.; Kavzoglu, T.; Tonbul, H.
Effects of forest fires and implications are one of the most important natural disasters all over the world. Statistical data observed that forest fires had a variable structure in the last century in Turkey, but correspondingly the population growth amount of forest fires and burn area increase widely in recent years. Depending on this, erosion, landslides, desertification and mass loss come into existence. In addition; after forest fires, renewal of forests and vegetation are very important for land management. Classic methods used for detection of burn area and severity requires a long and challenging process due to time and cost factors. Thanks to advanced techniques used in the field of Remote Sensing, burn area and severity can be determined with high detail and precision. The purpose of this study based on blending MODIS (Moderate Resolution Imaging Spectradiometer) satellite images and spatial autocorrelation techniques together, thus detect burn area and severity absolutely. In this context, spatial autocorrelation statistics like Moran's I and Get is-Ord Local Gi indexes were used to measure and analyze to burned area characteristics. Prefire and postfire satellite images were used to determine fire severity depending on spectral indexes corresponding to biomass loss and carbon emissivity intensities. Satellite images have used for identification of fire damages and risks in terms of fire management for a long time. This study was performed using prefire and postfire satellite images and spatial autocorrelation techniques to determining and analyzing forest fires in Antalya, Turkey region which serious fires occurred. In this context, this approach enables the characterization of distinctive texture of burned area and helps forecasting more precisely. Finally, it is observed that mapping of burned area and severity could be performed from local scale to national scale. Key Words: Spatial autocorrelation, MODIS, Fire, Burn Severity
González-Pérez, José A.; Jiménez-Morillo, Nicasio T.; Jordán, Antonio; Zavala, Lorena M.; Granged, Arturo J. P.; González-Vila, Francisco J.
Post-fire rehabilitation actions and recovery attempts of burned soils include a range of management practices (tillage, tree logging, reforestation …), in some cases producing an additional damage to that directly caused by fire. Among negative impacts derived from unappropriated rehab practices are the increase soil erosion, loss of soil fertility and alterations in the hydrological cycle. Analytical pyrolysis (Py-GC/MS) is an appropriate technique to study organic matter characteristics within complex matrices. Here this technique is used to study the alterations caused by burning and post-fire rehab plans to soil organic matter (SOM). Fire and post-fire rehab actions impact on SOM is studied in a sandy soil under pine (Pinus pinea) forest that was affected by a severe fire in August 2012 in Doñana National Park (SW Spain). Bulk samples as well as its sieved soil fractions (coarse, 1-2 mm, and fine, <0.05 mm) collected from an undisturbed burned area (B) and in an adjacent burned area after rehab practices (BR) (logging and extraction of burned trees) were studied. An additional adjacent unburned (UB) area was used as a control. Conspicuous differences among bulk samples from the B, BR and UB control areas were found in the relative proportions of the main molecular families obtained by analytical pyrolysis, including alkane/alkene pairs, unspecific aromatic compounds (UAC), peptides, methoxyphenols, fatty acids, carbohydrates, N-compounds and polycyclic aromatic hydrocarbons (PAH). The B site SOM showed lower proportion of lignin methoxyphenols and higher of UAC and PAH than the SOM from the UB site. This indicates that fire produced methoxyphenol de-functionalization, increasing the proportion of recalcitrant compounds. With respect to soil size fractions, in all cases, the coarse fraction showed a high content of carbohydrate-derived compounds and methoxyphenols followed by fatty acids, in line with inputs of new litter from stressed post-fire vegetation
Lutz, J.A.; Key, C.H.; Kolden, C.A.; Kane, J.T.; van Wagtendonk, J.W.
Fire frequency, area burned, and fire severity are important attributes of a fire regime, but few studies have quantified the interrelationships among them in evaluating a fire year. Although area burned is often used to summarize a fire season, burned area may not be well correlated with either the number or ecological effect of fires. Using the Landsat data archive, we examined all 148 wildland fires (prescribed fires and wildfires) >40 ha from 1984 through 2009 for the portion of the Sierra Nevada centered on Yosemite National Park, California, USA. We calculated mean fire frequency and mean annual area burned from a combination of field- and satellite-derived data. We used the continuous probability distribution of the differenced Normalized Burn Ratio (dNBR) values to describe fire severity. For fires >40 ha, fire frequency, annual area burned, and cumulative severity were consistent in only 13 of 26 years (50 %), but all pair-wise comparisons among these fire regime attributes were significant. Borrowing from long-established practice in climate science, we defined "fire normals" to be the 26 year means of fire frequency, annual area burned, and the area under the cumulative probability distribution of dNBR. Fire severity normals were significantly lower when they were aggregated by year compared to aggregation by area. Cumulative severity distributions for each year were best modeled with Weibull functions (all 26 years, r2 ??? 0.99; P < 0.001). Explicit modeling of the cumulative severity distributions may allow more comprehensive modeling of climate-severity and area-severity relationships. Together, the three metrics of number of fires, size of fires, and severity of fires provide land managers with a more comprehensive summary of a given fire year than any single metric.
Ruiz Gallardo, Jose Reyes
Wildland fires are one of the major causes of ecosystems degradation, especially in semiarid climates, where the erosion hazard is high. The identification of potential erosion zones is typically difficult as it requires expensive field and laboratory work. This PhD study proposes a methodology based on remote sensing and Geographical Information Systems (GIS) techniques, which permits speedy identification of erodable areas in a semi-automatic way, tested in three large wildfires in south-eastern Spain. Inputs to the model are slope and aspect of the burn scar and fire severity. A new method to obtain this last parameter (fire severity) has been proposed and examined vs. others of commonly used. The method is based on the difference in NDVI between two images (acquired before and after the fire event). Combining these maps in a GIS, a Forest Intervention Priority map (FIP) is produced, which identifies areas of high erosion potential. Field work was conducted to assess the method. Results indicate that the applied methodology reliably predicted the extent of very severe fire. Furthermore, the method was generally useful for identifying sites of significant erosion. Others results deal with spatial distribution of fire severity within the burn scar, with floristic studies of the test plots, and the relation among vegetal cover and different levels of fire severity, slope and aspect.
Lopez, Nicole E; Krzyzaniak, Michael; Costantini, Todd W; De Maio, Antonio; Baird, Andrew; Eliceiri, Brian P; Coimbra, Raul
Large surface area burn injuries lead to activation of the innate immune system, which can be blocked by parasympathetic inputs mediated by the vagus nerve. We hypothesized that vagal nerve stimulation (VNS) would alter the inflammatory response of peritoneal macrophages after severe burn injury. Male BALB/c mice underwent right cervical VNS before 30% total body surface area steam burn and were compared with animals subjected to burn alone. Peritoneal macrophages were harvested at several time points following injury and exposed to lipopolysaccharide (LPS) in culture conditions. The inflammatory response of peritoneal macrophages was measured by analyzing changes in nuclear factor κB p65 phosphorylation using flow cytometry. We found that peritoneal macrophages isolated from mice subjected to burn injury were hyperresponsive to LPS challenge, suggesting burn-induced macrophage activation. We identified a protective role for VNS in blocking peritoneal macrophage activation. Analysis of the phosphorylation state of nuclear factor κB pathway mediator, p65 Rel A, revealed a VNS-mediated reduction in p65 phosphorylation levels after exposure to LPS compared with burn alone. In combination, these studies suggest VNS mediates the inflammatory response in peritoneal macrophages by affecting the set point of LPS responsiveness. PMID:22683732
Karau, Eva C; Sikkink, Pamela G; Keane, Robert E; Dillon, Gregory K
Both satellite imagery and spatial fire effects models are valuable tools for generating burn severity maps that are useful to fire scientists and resource managers. The purpose of this study was to test a new mapping approach that integrates imagery and modeling to create more accurate burn severity maps. We developed and assessed a statistical model that combines the Relative differenced Normalized Burn Ratio, a satellite image-based change detection procedure commonly used to map burn severity, with output from the Fire Hazard and Risk Model, a simulation model that estimates fire effects at a landscape scale. Using 285 Composite Burn Index (CBI) plots in Washington and Montana as ground reference, we found that an integrated model explained more variability in CBI (R (2) = 0.47) and had lower mean squared error (MSE = 0.28) than image (R (2) = 0.42 and MSE = 0.30) or simulation-based models (R (2) = 0.07 and MSE = 0.49) alone. Overall map accuracy was also highest for maps created with the Integrated Model (63 %). We suspect that Simulation Model performance would greatly improve with higher quality and more accurate spatial input data. Results of this study indicate the potential benefit of combining satellite image-based methods with a fire effects simulation model to create improved burn severity maps. PMID:24817334
Karau, Eva C.; Sikkink, Pamela G.; Keane, Robert E.; Dillon, Gregory K.
Both satellite imagery and spatial fire effects models are valuable tools for generating burn severity maps that are useful to fire scientists and resource managers. The purpose of this study was to test a new mapping approach that integrates imagery and modeling to create more accurate burn severity maps. We developed and assessed a statistical model that combines the Relative differenced Normalized Burn Ratio, a satellite image-based change detection procedure commonly used to map burn severity, with output from the Fire Hazard and Risk Model, a simulation model that estimates fire effects at a landscape scale. Using 285 Composite Burn Index (CBI) plots in Washington and Montana as ground reference, we found that an integrated model explained more variability in CBI ( R 2 = 0.47) and had lower mean squared error (MSE = 0.28) than image ( R 2 = 0.42 and MSE = 0.30) or simulation-based models ( R 2 = 0.07 and MSE = 0.49) alone. Overall map accuracy was also highest for maps created with the Integrated Model (63 %). We suspect that Simulation Model performance would greatly improve with higher quality and more accurate spatial input data. Results of this study indicate the potential benefit of combining satellite image-based methods with a fire effects simulation model to create improved burn severity maps.
Fernández-Manso, Alfonso; Fernández-Manso, Oscar; Quintano, Carmen
Fires are a problematic and recurrent issue in Mediterranean ecosystems. Accurate discrimination between burn severity levels is essential for the rehabilitation planning of burned areas. Sentinel-2A MultiSpectral Instrument (MSI) record data in three red-edge wavelengths, spectral domain especially useful on agriculture and vegetation applications. Our objective is to find out whether Sentinel-2A MSI red-edge wavelengths are suitable for burn severity discrimination. As study area, we used the 2015 Sierra Gata wildfire (Spain) that burned approximately 80 km2. A Copernicus Emergency Management Service (EMS)-grading map with four burn severity levels was considered as reference truth. Cox and Snell, Nagelkerke and McFadde pseudo-R2 statistics obtained by Multinomial Logistic Regression showed the superiority of red-edge spectral indices (particularly, Modified Simple Ratio Red-edge, Chlorophyll Index Red-edge, Normalized Difference Vegetation Index Red-edge) over conventional spectral indices. Fisher's Least Significant Difference test confirmed that Sentinel-2A MSI red-edge spectral indices are adequate to discriminate four burn severity levels.
Sanz, Inés; Aguilar, Cristina; Millares, Agustín
In the last fifty years, forest fires and changes in land use and management practices have had a significant influenceon the evolution of soil loss processes in the Mediterranean area. Forest fires have immediate effects in hydrological processes mainly due to sudden changes in soil properties and vegetation cover. After a fire there is an increase in runoff processes and peak flows and thus in the amount and composition of the sediments produced. Silting in dams downstream is often reported so the description of the post-fire hydrological processes is crucial in order to optimize decision making. This study analyzes a micro-watershed of 25 ha in the south of Spain that suffered a fire in October 2010 burning around a 2 km2 area. As the erosive processes in this area are directly related to concentrated overland flow, an indirect assessment of soil loss is presented in this work based on evaluating changes in runoff in Mediterranean post-fire situations. For this, the study is divided into two main parts. Firstly, changes in soil properties and vegetation cover are evaluated. Secondly, the effects of these changes in the hydrological and erosive dynamics are assessed.The watershed had been monitored in previous studies so soil properties and the vegetation cover before the fire took place were already characterized. Besides, the hydrological response was also available through an already calibrated and validated physically-based distributed hydrological model. For the evaluation of soil properties, field measurement campaigns were designed. Philip Dunne's tests for the determination of saturated hydraulic conductivity, as well as moisture content and bulk density measurements were carried out in both unaltered and burned soil samples. Changes in the vegetation cover fraction were assessed through desktop analysis of Landsat-TM5 platform satellite images as well as through visual inspection in the field campaigns. The analysis of the hydraulic conductivity revealed
Kaczynski, Kristen M.; Beatty, Susan W.; van Wagtendonk, Jan W.; Marshall, Kristin N.
We examined non-native species density three years after the Tuolumne Fire, which burned 1540 ha in upper montane forest in California, USA. We sampled 60 plots, stratified by burn severity (low, moderate, or high severity) and landscape position (lowland or upland). We detected non-native species in 8 of 11 (73 %) of high severity lowland sites and in 5 of 10 (50 %) of moderate severity lowland sites but, overall, richness and abundance was low. We detected only five non-native species, of which bull thistle (Cirsium vulgare [Savi] Ten.) was the most common. Although non-native abundance is currently low, we recommend continued low intensity monitoring, especially on high severity burned lowland sites.
Chen, Gang; Metz, Margaret R.; Rizzo, David M.; Dillon, Whalen W.; Meentemeyer, Ross K.
Forest ecosystems are subject to a variety of disturbances with increasing intensities and frequencies, which may permanently change the trajectories of forest recovery and disrupt the ecosystem services provided by trees. Fire and invasive species, especially exotic disease-causing pathogens and insects, are examples of disturbances that together could pose major threats to forest health. This study examines the impacts of fire and exotic disease (sudden oak death) on forests, with an emphasis on the assessment of post-fire burn severity in a forest where trees have experienced three stages of disease progression pre-fire: early-stage (trees retaining dried foliage and fine twigs), middle-stage (trees losing fine crown fuels), and late-stage (trees falling down). The research was conducted by applying Geographic Object-Based Image Analysis (GEOBIA) to MASTER airborne images that were acquired immediately following the fire for rapid assessment and contained both high-spatial (4 m) and high-spectral (50 bands) resolutions. Although GEOBIA has gradually become a standard tool for analyzing high-spatial resolution imagery, high-spectral resolution data (dozens to hundreds of bands) can dramatically reduce computation efficiency in the process of segmentation and object-based variable extraction, leading to complicated variable selection for succeeding modeling. Hence, we also assessed two widely used band reduction algorithms, PCA (principal component analysis) and MNF (minimum noise fraction), for the delineation of image objects and the subsequent performance of burn severity models using either PCA or MNF derived variables. To increase computation efficiency, only the top 5 PCA and MNF and top 10 PCA and MNF components were evaluated, which accounted for 10% and 20% of the total number of the original 50 spectral bands, respectively. Results show that if no band reduction was applied the models developed for the three stages of disease progression had relatively
Porter, Craig; Herndon, David N; Bhattarai, Nisha; Ogunbileje, John O; Szczesny, Bartosz; Szabo, Csaba; Toliver-Kinsky, Tracy; Sidossis, Labros S
Chronic cold exposure induces functionally thermogenic mitochondria in the inguinal white adipose tissue (iWAT) of mice. Whether this response occurs in pathophysiological states remains unclear. The purpose of this study was to determine the impact of severe burn trauma on iWAT mitochondrial function in mice. Male BALB/c mice (10-12 weeks) received full-thickness scald burns to ∼30% of the body surface area. Inguinal white adipose tissue was harvested from mice at 1, 4, 10, 20, and 40 days postinjury. Total and uncoupling protein 1 (UCP1)-dependent mitochondrial thermogenesis were determined in iWAT. Citrate synthase activity was determined as a proxy of mitochondrial abundance. Immunohistochemistry was performed to assess iWAT morphology and UCP1 expression. Uncoupling protein 1-dependent respiration was significantly greater at 4 and 10 days after burn compared with sham, peaking at 20 days after burn (P < 0.001). Citrate synthase activity was threefold greater at 4, 10, 20, and 40 days after burn versus sham (P < 0.05). Per mitochondrion, UCP1 function increased after burn trauma (P < 0.05). After burn trauma, iWAT exhibited numerous multilocular lipid droplets that stained positive for UCP1. The current findings demonstrate the induction of thermogenically competent mitochondria within rodent iWAT in a model of severe burn trauma. These data identify a specific pathology that induces the browning of white adipose tissue in vivo and may offer a mechanistic explanation for the chronic hypermetabolism observed in burn victims. PMID:26009824
Jones, B.; Kolden, C.; Jandt, R.; Abatzoglou, J.; Urban, F.; Arp, C.
In 2007, the Anaktuvuk River Fire (ARF) became the largest recorded tundra fire on the North Slope of Alaska. The ARF burned for nearly three months, consuming more than 100,000 ha. At its peak in early September, the ARF burned at a rate of 7000 ha d-1. The conditions potentially responsible for this large tundra fire include modeled record high summer temperature and record low summer precipitation, a late-season high-pressure system located over the Beaufort Sea, extremely dry soil conditions throughout the summer, and sustained southerly winds during the period of vegetation senescence. Burn severity mapping revealed that more than 80% of the ARF burned at moderate to extreme severity, while the nearby Kuparuk River Fire remained small and burned at predominantly (80%) low severity. While this study provides information that may aid in the prediction of future large tundra fires in northern Alaska, the fact that three other tundra fires that occurred in 2007 combined to burn less than 1000 ha suggests site specific complexities associated with tundra fires on the North Slope, which may hamper the development of tundra fire forecasting models.
Narayanaraj, Ganapathy; Wimberly, Michael C.
Previous research has shown that forest roads are an important feature in many landscapes and have significant effects on wildfire ignition and cessation. However, forest road effects on burn severity have not been studied at the landscape level. Therefore, the overarching goal of our study is to identify the influences of road edge effects on the spatial patterns of burn severity. We analyzed six fires within the Okanogan-Wenatchee National Forest on the eastern slope of the Cascades mountain range of central Washington. We generated two categories for assessing road variables: (1) Primary Road Effect Zone (area within 150 m of the nearest road) and (2) Secondary Road Effect Zone (area from 150 m to 300 m to the nearest road). A regular sampling grid including one out of every 9 cells was created for each fire. These grids were intersected with burn severity data in the form of the Relative Differenced Normalized Burn Ratio (RdNBR), road distance category, stream distance, elevation, slope, terrain shape index, heat load index, canopy cover, and fuel type. We fit spatial regression models with RdNBR as the dependent variable. We found that high burn severity is less likely to occur in the Primary Road Effect Zone for most fires, although one fire exhibited the opposite relationship. Forest road edge effects were hypothesized to be an important determinant of burn severity because fragmentation created by roads alters the roadside fuel profile and environment and because road corridors create barriers to fire spread. Recognizing roadside effects on burn severity patterns highlights the need for further study of the range of effects that roads have on fuels and the fire environment and the potential for incorporating road effects into landscape-level assessments of fire risk.
Finnerty, Celeste C; Jeschke, Marc G; Herndon, David N; Gamelli, Richard; Gibran, Nicole; Klein, Matthew; Silver, Geoff; Arnoldo, Brett; Remick, Daniel; Tompkins, Ronald G
A severe burn leads to hypermetabolism and catabolism resulting in compromised function and structural changes of essential organs. The release of cytokines has been implicated in this hypermetabolic response. The severity of the hypermetabolic response following burn injury increases with age, as does the mortality rate. Due to the relationship between the hypermetabolic and inflammatory responses, we sought to compare the plasma cytokine profiles following a severe burn in adults and in children. We enrolled 25 adults and 24 children who survived a flame burn covering more than 20% of total body surface area (TBSA). The concentrations of 22 cytokines were measured using the Linco multiplex array system (St. Charles, MO, USA). Large perturbations in the expression of pro- and anti-inflammatory cytokines were seen following thermal injury. During the first week following burn injury, IFN-γ, IL-10, IL-17, IL-4, IL-6, and IL-8 were detected at significantly higher levels in adults compared with children, P < 0.05. Significant differences were measured during the second week post-burn for IL-1β (higher in children) and IL-5 (higher in adults), P < 0.05. IL-18 was more abundant in children compared with adults during the third week post-burn, P < 0.05. Between post-burn d 21 and d 66, IL-1α was detected at higher concentrations in pediatric compared with adult patients, P < 0.05. Only GM-CSF expression was significantly different at all time points; it was detected at lower levels in pediatric patients, P < 0.05. Eotaxin, G-CSF, IL-13, IL-15, IP-10, MCP-1, and MIP-1α were detected at significantly different concentrations in adult compared with pediatric patients at multiple time points, P < 0.05. There were no differences in IL-12, IL-2, IL-7, or TNF levels in adult compared with pediatric burn patients at any of these time points. Following severe flame burns, the cytokine profiles in pediatric patients differ compared with those in adult patients, which may
... are burns treated? In many cases, topical antibiotics (skin creams or ointments) are used to prevent infection. For third-degree burns and some second-degree ones, immediate blood transfusion and/or extra fluids ... is skin grafting? There are two types of skin grafts. ...
Bai, Xiao-Zhi; He, Ting; Gao, Jian-Xin; Liu, Yang; Liu, Jia-Qi; Han, Shi-Chao; Li, Yan; Shi, Ji-Hong; Han, Jun-Tao; Tao, Ke; Xie, Song-Tao; Wang, Hong-Tao; Hu, Da-Hai
Acute kidney injury (AKI) is a common complication after severe burns. Melatonin has been reported to protect against multiple organ injuries by increasing the expression of SIRT1, a silent information regulator that regulates stress responses, inflammation, cellular senescence and apoptosis. This study aimed to investigate the protective effects of melatonin on renal tissues of burned rats and the role of SIRT1 involving the effects. Rat severely burned model was established, with or without the administration of melatonin and SIRT1 inhibitor. The renal function and histological manifestations were determined to evaluate the severity of kidney injury. The levels of acetylated-p53 (Ac-p53), acetylated-p65 (Ac-p65), NF-κB, acetylated-forkhead box O1 (Ac-FoxO1), Bcl-2 and Bax were analyzed to study the underlying mechanisms. Our results suggested that severe burns could induce acute kidney injury, which could be partially reversed by melatonin. Melatonin attenuated oxidative stress, inflammation and apoptosis accompanied by the increased expression of SIRT1. The protective effects of melatonin were abrogated by the inhibition of SIRT1. In conclusion, we demonstrate that melatonin improves severe burn-induced AKI via the activation of SIRT1 signaling. PMID:27599451
Bai, Xiao-Zhi; He, Ting; Gao, Jian-Xin; Liu, Yang; Liu, Jia-Qi; Han, Shi-Chao; Li, Yan; Shi, Ji-Hong; Han, Jun-Tao; Tao, Ke; Xie, Song-Tao; Wang, Hong-Tao; Hu, Da-Hai
Acute kidney injury (AKI) is a common complication after severe burns. Melatonin has been reported to protect against multiple organ injuries by increasing the expression of SIRT1, a silent information regulator that regulates stress responses, inflammation, cellular senescence and apoptosis. This study aimed to investigate the protective effects of melatonin on renal tissues of burned rats and the role of SIRT1 involving the effects. Rat severely burned model was established, with or without the administration of melatonin and SIRT1 inhibitor. The renal function and histological manifestations were determined to evaluate the severity of kidney injury. The levels of acetylated-p53 (Ac-p53), acetylated-p65 (Ac-p65), NF-κB, acetylated-forkhead box O1 (Ac-FoxO1), Bcl-2 and Bax were analyzed to study the underlying mechanisms. Our results suggested that severe burns could induce acute kidney injury, which could be partially reversed by melatonin. Melatonin attenuated oxidative stress, inflammation and apoptosis accompanied by the increased expression of SIRT1. The protective effects of melatonin were abrogated by the inhibition of SIRT1. In conclusion, we demonstrate that melatonin improves severe burn-induced AKI via the activation of SIRT1 signaling. PMID:27599451
Alanís, Nancy; Jordán, Antonio; Zavala, Lorena M.
Forest fires usually intensify erosive process due to the reduction of vegetation cover and degradation of aggregation in the topsoil. Another common effect of wildifres is the development of soil water repellency, which in turn favors the formation of runoff, inhibiting or delaying infiltration. Under these conditions, infiltration occurs only when ponded water or runoff flow finds macropores and cracks in the soil surface, producing preferential flow pathways. When water infiltrates through these paths, a significant portion of the soil remains dry, limiting the supply of nutrients to the roots, favoring the rapid leaching of nutrients and agrochemicals, and other impacts on flora and hydrological processes at hillslope- or basin-scale. The existence of irregular wetting fronts has been observed frequently in burned or unburned water repellent soils. Although some authors have suggested that preferential flow paths may be more or less permanent in the case of unburned soils, the temporal evolution of preferential flow has been rarely studied in burned soils during the post-fire, after water repellency decreases or disappears. This research focuses on the temporal evolution of water repellency and preferential flows in an area affected by fire.
Chua, Alvin Wen Choong; Khoo, Yik Cheong; Tan, Bien Keem; Tan, Kok Chai; Foo, Chee Liam; Chong, Si Jack
Current advances in basic stem cell research and tissue engineering augur well for the development of improved cultured skin tissue substitutes: a class of products that is still fraught with limitations for clinical use. Although the ability to grow autologous keratinocytes in-vitro from a small skin biopsy into sheets of stratified epithelium (within 3 to 4 weeks) helped alleviate the problem of insufficient donor site for extensive burn, many burn units still have to grapple with insufficient skin allografts which are used as intermediate wound coverage after burn excision. Alternatives offered by tissue-engineered skin dermal replacements to meet emergency demand have been used fairly successfully. Despite the availability of these commercial products, they all suffer from the same problems of extremely high cost, sub-normal skin microstructure and inconsistent engraftment, especially in full thickness burns. Clinical practice for severe burn treatment has since evolved to incorporate these tissue-engineered skin substitutes, usually as an adjunct to speed up epithelization for wound closure and/or to improve quality of life by improving the functional and cosmetic results long-term. This review seeks to bring the reader through the beginnings of skin tissue engineering, the utilization of some of the key products developed for the treatment of severe burns and the hope of harnessing stem cells to improve on current practice. PMID:27574673
Tepley, A. J.; Veblen, T. T.; Perry, G.; Anderson-Teixeira, K. J.
In the face of on-going climatic warming and land-use change, there is growing concern that temperate forest landscapes could be near a tipping point where relatively small changes to the fire regime or altered post-fire vegetation dynamics could lead to extensive conversion to shrublands or savannas. To evaluate vulnerability and resilience to such conversion, we develop a simple model based on three factors we hypothesize to be key in predicting temperate forest responses to changing fire regimes: (1) the hazard rate (i.e., the probability of burning in the next year given the time since the last fire) in closed-canopy forests, (2) the hazard rate for recently-burned, open-canopy vegetation, and (3) the time to redevelop canopy closure following fire. We generate a response surface representing the proportions of the landscape potentially supporting closed-canopy forest and non-forest vegetation under nearly all combinations of these three factors. We then place real landscapes on this response surface to assess the type and magnitude of changes to the fire regime that would drive extensive forest loss. We show that the deforestation of much of New Zealand that followed initial human colonization and the introduction of a new ignition source ca. 750 years ago was essentially inevitable due to the slow rate of forest recovery after fire and the high flammability of post-fire vegetation. In North America's Pacific Northwest, by contrast, a predominantly forested landscape persisted despite two periods of widespread burning in the recent past due in large part to faster post-fire forest recovery and less pronounced differences in flammability between forests and the post-fire vegetation. We also assess the factors that could drive extensive deforestation in other regions to identify where management could reduce this potential and to guide field and modeling work to better understand the responses and ecological feedbacks to changing fire regimes.
Przkora, Rene; Jeschke, Marc G.; Barrow, Robert E.; Suman, Oscar E.; Meyer, Walter J.; Finnerty, Celeste C.; Sanford, Arthur P.; Lee, Jong; Chinkes, David L.; Mlcak, Ronald P.; Herndon, David N.
Objective: When given to children for 1 year after a severe burn, oxandrolone significantly improves lean body mass, bone mineral content, and muscle strength. The beneficial effects of oxandrolone on height and weight were observed 1 year after treatment was discontinued. To study the efficacy of oxandrolone in severely burned children for 12 months after burn and 12 months after the drug was discontinued. Summary Background Data: Oxandrolone attenuates body catabolism during the acute phase after burn. It is unclear whether oxandrolone would have any beneficial effects during long-term treatment or if there were any effects after the drug was stopped. Methods: Sixty-one children with 40% total body surface area burns were enrolled in this study. Patients were randomized into those to receive oxandrolone (n = 30) or placebo (n = 31) for the first 12 months. Treatment was discontinued after 12 months, and the patients were studied without the drug for the following 12 months. At discharge and 6, 12, 18, and 24 months after burn, height, weight, body composition, resting energy expenditure, muscle strength, and serum human growth hormone, insulin-like growth factor-I (IGF-1), IGF binding protein-3, insulin, cortisol, parathyroid hormone, tri-iodothyronine uptake (T3 uptake), and free thyroxine index (FTI) were measured. Statistical analysis used Tukey multiple comparison test. Significance was accepted at P < 0.05. Results: Oxandrolone improved lean body mass, bone mineral content and muscle strength compared with controls during treatment, P < 0.05. Serum IGF-1, T3 uptake, and FTI were significantly higher during drug treatment compared with controls, P < 0.05. Significant increases in height and weight with oxandrolone were observed after the end of treatment. Conclusions: Oxandrolone improved body composition and strength in severely burned children during the 12 months of treatment. Its effect on height and weight continued after treatment was discontinued. PMID
Pham, Tam N.; Klein, Matthew B.; Gibran, Nicole S.; Arnoldo, Brett D.; Gamelli, Richard L.; Silver, Geoffrey M.; Jeschke, Marc G.; Finnerty, Celeste C.; Tompkins, Ronald G.; Herndon, David N.
Pharmacologic modulation of hypermetabolism clearly benefits children with major burns, however, its role in adult burns remains to be defined. Oxandrolone appears to be a promising anabolic agent although few outcome data are as yet available. We examined whether early oxandrolone treatment in severely burned adults was associated with improved outcomes during acute hospitalization. We evaluated for potential associations between oxandrolone treatment and outcomes in a large cohort of severely burned adults in the context of a multicenter observational study. Patients were dichotomized with respect to oxandrolone treatment, defined as administration within 7 days after admission, with duration of at least 7 days. Acute hospitalization outcomes were compared with univariate and multivariate analyses. One hundred seventeen patients were included in this analysis. Mean patient age was 42.6 years (range, 18–86); 77% were male, with an average TBSA of 44.1%. Baseline and injury characteristics were similar among treatment and nontreatment cohorts. Oxandrolone treatment (N =59) did not impact length of stay but was associated with a lower mortality rate (P = .01) by univariate analysis. Oxandrolone treatment was independently associated with higher survival by adjusted analyses (P = .02). Examination of early oxandrolone treatment in this cohort of severely burned adults suggests that this therapy is safe and may be associated with improved survival. Further studies are necessary to define the exact mechanisms by which oxandrolone is beneficial during inpatient treatment. PMID:18849836
... to your body's tissues caused by heat, chemicals, electricity, sunlight, or radiation. Scalds from hot liquids and ... to infections because they damage your skin's protective barrier. Treatment for burns depends on the cause of ...
... of Surgery . 18th ed. Philadelphia, PA: Elsevier Saunders; 2007:chap 22. Holmes JH, Heimbach DM. Burns. In: Brunicardi FC, Andersen DK, Billiar TR, et al, eds. Schwartz's Principles of Surgery . 9th ed. New ...
Herndon, David N.; Rodriguez, Noe A.; Diaz, Eva C.; Hegde, Sachin; Jennings, Kristofer; Mlcak, Ronald P.; Suri, Jaipreet S.; Lee, Jong O.; Williams, Felicia N.; Meyer, Walter; Suman, Oscar E.; Barrow, Robert E.; Jeschke, Marc G.; Finnerty, Celeste C.
Objective To determine the safety and efficacy of propranolol given for 1 year on cardiac function, resting energy expenditure, and body composition in a prospective randomized single-center controlled study in pediatric patients with large burns. Summary Background Data Severe burns trigger a hypermetabolic response that persists for up to 2 years after burn. Propranolol given for 1 month post burn blunts this response. Whether propranolol administration for 1 year after injury provides a continued benefit is currently unclear. Methods One-hundred seventy nine pediatric patients with >30% total body surface area burns were randomized to receive control (n = 89) or 4 mg/kg/d propranolol (n = 90) for 12 months after burn. Changes in resting energy expenditure, cardiac function, and body composition were measured acutely at 3, 6, 9, and 12 months postburn. Statistical analyses included techniques that adjust for non-normality, repeated measures, and regression analyses. P <0.05 was considered significant. Results Long-term propranolol treatment significantly reduced the percent of the predicted heart rate and percent of the predicted resting energy expenditure, decreased accumulation of central mass and central fat, prevented bone loss, and improved lean body mass accretion. There were very few adverse effects from the dose of propranolol used. Conclusions Propranolol treatment for 12 months, following thermal injury, ameliorates the hyperdynamic, hypermetabolic, hypercatabolic, and osteopenic responses in pediatric patients. This study is registered at clinicaltrials.gov, NCT00675714. PMID:22895351
Prats, Sergio A.; Wagenbrenner, Joseph W.; Martins, Martinho M. A.; Keizer, Jan Jacob
Wildfires can have striking direct and indirect impacts on soils, including extreme runoff-erosion responses with serious negative consequences for land-use sustainability and downstream values-at-risk. Arguably, the best manner to reduce post-fire soil erosion consists of rapid application of a protective layer of "mulch", comprising straw, needles or wood-based materials. In this study, we assessed the efficacy of forest residue mulching for reducing runoff and soil erosion across two spatial scales, i.e. micro-plots of approximately 0.25 m2 vs. slope-scale plots of roughly 100 m2. We did so for a eucalypt plantation in north-central Portugal during the first two years following a moderate severity fire. We also tried to analyse which were the key factors underlying the erosive observed at untreated plots, with a special focus on soil moisture content and soil water repellencyf requency. . Forest residue mulch reduced post-fire runoff by around 50% and post-fire soil losses by about 90% at both plot scales. However, runoff was 10 times higher at the scale of the micro- than slope-scale plots. By contrast, soil erosion was "only" two times higher at the micro- than slope-scale plots. The main factor explaining runoff was rainfall intensity, while the main factor accounting for soil erosion was ground cover. Both soil moisture and soil water repellency played a secondary role in explaining the post-fire hydrologic response. This reflected the fact that neither of both factors differed markedly between the mulched and control conditions. Our results indicated that forest residue mulch was first and foremost an effective method due to the fact that it substantially increased ground cover.
Alves-Silva, Estevão; Del-Claro, Kleber
Fires in the Cerrado savanna are a severe form of disturbance, but some species are capable of resprouting afterwards. It is unknown, however, how and whether post-fire resprouting represents a stressful condition to plants and how their rapid re-growth influences both the production of biochemical compounds, and interactions with mutualistic ants. In this study, we examined the influence of post-fire resprouting on biotic interactions (ant-plant-herbivore relationships) and on plant stress. The study was performed on two groups of the extrafloral nectaried shrub Banisteriopsis campestris (Malpighiaceae); one group was recovering from fire while the other acted as control. With respect to biotic interactions, we examined whether resprouting influenced extrafloral nectar concentration (milligrams per microliter), the abundance of the ant Camponotus crassus and leaf herbivory rates. Plant stress was assessed via fluctuating asymmetry (FA) analysis, which refers to deviations from perfect symmetry in bilaterally symmetrical traits (e.g., leaves) and indicates whether species are under stress. Results revealed that FA, sugar concentration, and ant abundance were 51.7 %, 35.7 % and 21.7 % higher in resprouting plants. Furthermore, C. crassus was significantly associated with low herbivory rates, but only in resprouting plants. This study showed that post-fire resprouting induced high levels of plant stress and influenced extrafloral nectar quality and ant-herbivore relationships in B. campestris. Therefore, despite being a stressful condition to the plant, post-fire resprouting individuals had concentrated extrafloral nectar and sustained more ants, thus strengthening the outcomes of ant-plant mutualism. PMID:23625518
Alves-Silva, Estevão; Del-Claro, Kleber
Fires in the Cerrado savanna are a severe form of disturbance, but some species are capable of resprouting afterwards. It is unknown, however, how and whether post-fire resprouting represents a stressful condition to plants and how their rapid re-growth influences both the production of biochemical compounds, and interactions with mutualistic ants. In this study, we examined the influence of post-fire resprouting on biotic interactions (ant-plant-herbivore relationships) and on plant stress. The study was performed on two groups of the extrafloral nectaried shrub Banisteriopsis campestris (Malpighiaceae); one group was recovering from fire while the other acted as control. With respect to biotic interactions, we examined whether resprouting influenced extrafloral nectar concentration (milligrams per microliter), the abundance of the ant Camponotus crassus and leaf herbivory rates. Plant stress was assessed via fluctuating asymmetry (FA) analysis, which refers to deviations from perfect symmetry in bilaterally symmetrical traits (e.g., leaves) and indicates whether species are under stress. Results revealed that FA, sugar concentration, and ant abundance were 51.7 %, 35.7 % and 21.7 % higher in resprouting plants. Furthermore, C. crassus was significantly associated with low herbivory rates, but only in resprouting plants. This study showed that post-fire resprouting induced high levels of plant stress and influenced extrafloral nectar quality and ant-herbivore relationships in B. campestris. Therefore, despite being a stressful condition to the plant, post-fire resprouting individuals had concentrated extrafloral nectar and sustained more ants, thus strengthening the outcomes of ant-plant mutualism.
Burke, M. P.; Ferreira, M.; Hogue, T. S.; Jay, J.; Rademacher, L. K.
Wildfire alters terrestrial stores of mercury (Hg) within a watershed, releasing Hg to the atmosphere and creating conditions that can be conducive to Hg export in streamwater. Hg transport to terrestrial waters is often associated with suspended sediments and organic matter, and particulate-bound Hg delivery to downstream water bodies may be enhanced following wildfire. Burned watersheds experience increased overland flow, soil erosion, sediment transport, and, consequently, transport of sediment bound contaminants during early post-fire storm events. Southern California’s September 2006 Day Fire consumed 660km2 and almost 50% of the 512km2 Piru Creek watershed. Piru Creek drains into Pyramid Lake, a storage reservoir for the California State Water Project, which provides drinking water for Los Angeles. Streamwater was collected from Piru Creek watershed over a 1.5 year period following the Day Fire, on a monthly basis during low flow periods, and every two hours during storm events using an automated sampler. Samples were analyzed for both dissolved and total Hg, total suspended solids, and basic anions and cations. Low Hg concentrations (> 1ng Hg/ L dissolved and > 5ng Hg/L total) were measured in inter-storm samples. The first winter (2006-07) following the Day Fire was one of the driest on record, with precipitation totals (130mm) less than one third of normal. The only significant storm measured total Hg concentrations just slightly higher than the inter-storm samples, while no change was observed in the dissolved Hg concentrations. However, these total Hg concentrations were well correlated to TSS measurements (r2 = 0.91) and followed the storm hydrograph. The following winter (2007-08) brought higher precipitation totals (370mm) and more intense storms. Elevated, turbid stream flow was observed in Piru Creek during many of the 2007-08 storms. Little change was observed in the dissolved Hg concentrations of the storm samples; however, a two-order magnitude
Finnerty, Celeste C; Herndon, David N; Jeschke, Marc G
Introduction Inhalation injury in combination with a severe thermal injury increases mortality. Alterations in inflammatory mediators, such as cytokines, contribute to the incidence of multi-organ failure and mortality. The aim of the present study was to determine the effect of inhalation injury on cytokine expression in severely burned children. Methods Thirty severely burned pediatric patients with inhalation injury and 42 severely burned children without inhalation injury were enrolled in the study. Inhalation injury was diagnosed by bronchoscopy during the first operation. Blood was collected within 24 hours of admission and again at five to seven days following admission. Cytokine expression was profiled using multi-plex antibody-coated beads. Significance was accepted at a p value of less than 0.05. Results The mean percentages of total body surface area burned were 67% ± 4% (56% ± 6%, third-degree burns) in the inhalation injury group and 60% ± 3% (45% ± 3%, third-degree burns) in the non-inhalation injury group (p value not significant [NS]). Mean age was 9 ± 1 years in the inhalation injury group and 8 ± 1 years in the non-inhalation injury group (p value NS). Time from burn to admission in the inhalation injury group was 2 ± 1 days compared to 3 ± 1 days in the non-inhalation injury group (p value NS). Mortalities were 40% in the inhalation injury group and 12% in the non-inhalation injury group (p < 0.05). At the time of admission, serum interleukin (IL)-7 was significantly increased in the non-inhalation injury group, whereas IL-12p70 was significantly increased in the inhalation injury group compared to the non-inhalation injury group (p < 0.05). There were no other significant differences between groups. Five to seven days following admission, all cytokines decreased with no differences between the inhalation injury and non-inhalation injury cohorts. Conclusion In the present study, we show that an inhalation injury causes alterations in IL-7
Kurmis, Rochelle; Greenwood, John; Aromataris, Edoardo
Trace elements have an important physiological role after severe burn injury with patients routinely receiving supplementation. Although commonly prescribed after burn injury, variation exists among supplement composition, frequency, and the dosage administered. This review aims to assess the effectiveness of trace element supplementation on clinically meaningful outcomes in patients who have sustained a severe burn injury. Supplementation of selenium, copper and zinc, either alone or combined, compared with placebo or standard treatment were eligible for inclusion. Predetermined primary outcome measures were mortality, length of stay, rate of wound healing, and complications. A comprehensive search strategy was undertaken. Methodological quality of eligible studies was appraised and relevant data extracted for meta-analysis. Eight studies met eligibility criteria for the review; four randomized controlled trials and four nonrandomized experimental trials, including a total of 398 participants with an age range of 6 to 67 years. Parenteral supplementation of combined trace elements was associated with a significant decrease in infectious episodes (weighted mean difference: -1.25 episodes, 95% confidence intervals: -1.70, -0.80; P < .00001). The results of this review indicate that the use of parentally administered combined trace elements after burn injury confer positive effects in decreasing infectious complications. Combined parenteral trace element supplementation and combined oral and parenteral zinc supplementation have potentially clinically significant findings on reducing length of stay. Oral zinc supplementation shows possible beneficial effects on mortality. Definitive studies are required to accurately define optimal trace element supplementation regimens, dosages, and routes after burn injury. PMID:26056754
Staley, Dennis; Negri, Jacquelyn; Kean, Jason
burned areas. Our approach synthesizes the two methods by incorporating measured rainfall intensity into each model variable (based on measures of topographic steepness, burn severity and surface properties) within the logistic regression equation. This approach provides a more realistic representation of the relation between rainfall intensity and debris-flow likelihood, as likelihood values asymptotically approach zero when rainfall intensity approaches 0 mm/h, and increase with more intense rainfall. Model performance was evaluated by comparing predictions to several existing regional thresholds. The model, based upon training data collected in southern California, USA, has proven to accurately predict rainfall intensity-duration thresholds for other areas in the western United States not included in the original training dataset. In addition, the improved logistic regression model shows promise for emergency planning purposes and real-time, site-specific early warning. With further validation, this model may permit the prediction of spatially-explicit intensity-duration thresholds for debris-flow generation in areas where empirically derived regional thresholds do not exist. This improvement would permit the expansion of the early-warning system into other regions susceptible to post-fire debris flow.
Shinneman, D.J.; Baker, W.L.
Cheatgrass, a non-native annual grass, dominates millions of hectares in semiarid ecosystems of the Intermountain West (USA). Post-fire invasions can reduce native species diversity and alter ecological processes. To curb cheatgrass invasion, land managers often seed recently burned areas with perennial competitor species. We sampled vegetation within burned (19 years post-fire) and nearby unburned (representing pre-fire) pionjuniper (Pinus edulisJuniperus osteosperma) woodland and sagebrush (Artemisia sp.) in western Colorado to analyze variables that might explain cheatgrass cover after fire. A multiple regression model suggests higher cheatgrass cover after fire with: (1) sagebrush v. pionjuniper; (2) higher pre-fire cover of annual forbs; (3) increased time since fire; (4) lower pre-fire cover of biological soil crust; and (5) lower precipitation the year before fire. Time since fire, which coincided with higher precipitation, accounts for most of the variability in cheatgrass cover. No significant difference was found in mean cheatgrass cover between seeded and unseeded plots over time. However, negative relationships with pre-fire biological soil crust cover and native species richness suggest livestock-degraded areas are more susceptible to post-fire invasion. Proactive strategies for combating cheatgrass should include finding effective native competitors and restoring livestock-degraded areas. ?? 2009 IAWF.
Merino, Agustin; Fonturbel, M. Teresa; Vega, Jose A.
Severe wildfires can cause drastic changes in SOM content and quality with important implications for soil conservation and global C balance. Soil heating usually leads to loss of the most labile SOM compounds (e.g. carbohydrates, lipids and peptides) and to generation of aromatic substances. However, these fire-related damages are not uniform over large areas, because of the spatial heterogeneity of different factors such as fire type and environmental conditions. Rapid diagnosis of soil burn severity is required to enable the design of emergency post-fire rehabilitation treatments. The study was conducted in soils from NW Spain, an Atlantic-climate zone that is particularly prone to wildfires. Intact soil cores (forest floor and uppermost mineral soil layer) were taken from a soil developed under granitic rock and subjected to experimental burning (in a bench positioned at the outlet of a wind tunnel). Soil temperature during fire was monitorised and five visual levels of soil burn severity (SBS) were recorded immediately after fire. Solid-state 13C CP-MAS NMR spectroscopy analyses were performed in an Agilent (Varian) VNMRS-500-WB spectrometer. The samples were analyzed by differential scanning calorimetry and thermogravimetry (TGA/DSC, Mettler-Toledo Intl. Inc.). The analyses were performed with 4 mg of samples placed in open aluminium pans under dry air (flow rate, 50 mL-1) and at a scanning rate of 10 °C min-1. The temperature ranged between 50 and 600 °C. In the organic layer, the temperature reached during fire influenced the formation and characteristics of charred material. These materials showed an increasing degree of carbonization/aromatization in relation to the increase of temperature during burning. Burning also led to compounds of higher thermal recalcitrance (increases in T50 values -the temperature at which 50% of the energy stored in SOM is released-). However, values recorded in some samples were lower than those measured in highly
Herndon, David N.; Ramzy, Peter I.; DebRoy, Meelie A.; Zheng, Ming; Ferrando, Arny A.; Chinkes, David L.; Barret, Juan P.; Wolfe, Robert R.; Wolf, Steven E.
Objective To determine the effects of recombinant human insulin-like growth factor-1 (IGF-1) complexed with its principal binding protein, IGFBP-3, on skeletal muscle metabolism in severely burned children. Summary Background Data Severe burns are associated with a persistent hypermetabolic response characterized by hyperdynamic circulation and severe muscle catabolism and wasting. Previous studies showed that nutritional support and pharmacologic intervention with anabolic agents such as growth hormone and insulin abrogated muscle wasting and improved net protein synthesis in the severely burned. The use of these agents, however, has several adverse side effects. A new combination of IGF-1 and IGFBP-3 is now available for clinical study. Methods Twenty-nine severely burned children were prospectively studied before and after treatment with 0.5, 1, 2, or 4 mg/kg/day IGF-1/IGFBP-3 to determine net balance of protein across the leg, muscle protein fractional synthetic rates, and glucose metabolism. Another group was studied in a similar fashion without IGF-1/IGFBP-3 treatment as time controls. Results Seventeen of 29 children were catabolic before starting treatment. The infusion of 1.0 mg/kg/day IGF-1/IGFBP-3 increased serum IGF-1, which did not further increase with 2.0 and 4.0 mg/kg/day. IGF-1/IGFBP-3 treatment at 1 to 4 mg/kg/day improved net protein balance and increased muscle protein fractional synthetic rates. This effect was more pronounced in catabolic children. IGF-1/IGFBP-3 did not affect glucose uptake across the leg or change substrate utilization. Conclusions IGF-1/IGFBP-3 at doses of 1 to 4 mg/kg/day attenuates catabolism in catabolic burned children with negligible clinical side effects. PMID:10235530
Song, Juquan; Finnerty, Celeste C; Herndon, David N; Boehning, Darren; Jeschke, Marc G
Severe burn injury results in liver dysfunction and damage, with subsequent metabolic derangements contributing to patient morbidity and mortality. On a cellular level, significant postburn hepatocyte apoptosis occurs and likely contributes to liver dysfunction. However, the underlying mechanisms of hepatocyte apoptosis are poorly understood. The endoplasmic reticulum (ER) stress response/unfolded protein response (UPR) pathway can lead to hepatocyte apoptosis under conditions of liver dysfunction. Thus, we hypothesized that ER stress/UPR may mediate hepatic dysfunction in response to burn injury. We investigated the temporal activation of hepatic ER stress in mice after a severe burn injury. Mice received a scald burn over 35% of their body surface and were killed at 1, 7, 14, and 21 d postburn. We found that severe burn induces hepatocyte apoptosis as indicated by increased caspase-3 activity (P < 0.05). Serum albumin levels decreased postburn and remained lowered for up to 21 d, indicating that constitutive secretory protein synthesis was reduced. Significantly, upregulation of the ER stress markers glucose-related protein 78 (GRP78)/BIP, protein disulfide isomerase (PDI), p-protein kinase R-like endoplasmic reticulum kinase (p-PERK), and inositol-requiring enzyme 1alpha (IRE-1alpha) were found beginning 1 d postburn (P < 0.05) and persisted up to 21 d postburn (P < 0.05). Hepatic ER stress induced by burn injury was associated with compensatory upregulation of the calcium chaperone/storage proteins calnexin and calreticulin (P < 0.05), suggesting that ER calcium store depletion was the primary trigger for induction of the ER stress response. In summary, thermal injury in mice causes long-term adaptive and deleterious hepatic function alterations characterized by significant upregulation of the ER stress response. PMID:19603103
Li, Zhihong; Wang, Qihong; Yu, Haifeng; Zou, Kun; Xi, Yong; Mi, Wenxin; Ma, Yindong
Microarray analysis was performed to investigate the changes in gene expression profiles after severe burn injury at the early and middle stages, further discovering therapeutic targets for severe burn injury. Microarray data (GSE19743) were downloaded from Gene Expression Omnibus. First, differentially expressed genes (DEGs) at different stages were screened using limma package. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs were then performed using DAVID. Protein-protein interaction (PPI) networks were also constructed using String database. Additionally, transcription factor binding site was detected using the Whole-Genome rVISTA. Compared with the healthy controls, 160 DEGs were identified in patients with early-stage burn injury and 261 DEGs were obtained in patients with middle-stage burn injury. Only 10 genes showed differential expression between the early and middle stages. KEGG functional analysis indicated that DEGs detected at the early stage were mainly enriched in the immune response, kinase activity, and signaling pathways and DEGs detected at the middle stage were involved in the immune response, protein and fat metabolism, and programmed cell death pathways. Three PPI networks were constructed and hub proteins with high degrees of connection were screened, such as lactotransferrin, interleukin 8, and perforin-1. Additionally, many transcription factor binding sites that may be involved in the regulation of these DEGs were also detected. A number of DEGs were identified in patients with early- and middle-stage burn injury, which helps to deepen the understanding about the molecular mechanism underlying severe burn injury. PMID:25412053
Yan, Hong; Zhang, Yong; Lv, Shang-jun; Wang, Lin; Liang, Guang-ping; Wan, Qian-xue; Peng, Xi
Treatment with glutamine has been shown to reduce myocardial damage associated with ischemia/reperfusion injury. However, the cardioprotective effect of glutamine specifically after burn injury remains unclear. The present study explores the ability of glutamine to protect against myocardial damage in rats that have been severely burned. Seventy-two Wistar rats were randomly divided into three groups: normal controls (C), burned controls (B) and a glutamine-treated group (G). Groups B and G were subjected to full thickness burns comprising 30% of total body surface area. Group G was administered 1.5 g/ (kg•d) glutamine and group B was given the same dose of alanine via intragastric administration for 3 days. Levels of serum creatine kinase (CK), lactate dehydrogenase (LDH), aspartate transaminase (AST) and blood lactic acid were measured, as well as myocardial ATP and glutathione (GSH) contents. Cardiac function indices and histopathological changes were analyzed at 12, 24, 48 and 72 post-burn hours. In both burned groups, levels of serum CK, LDH, AST and blood lactic acid increased significantly, while myocardial ATP and GSH contents decreased. Compared with group B, CK, LDH, and AST levels were lower and blood lactic acid, myocardial ATP and GSH levels were higher in group G. Moreover, cardiac contractile function inhibition and myocardial histopathological damage were significantly reduced in group G compared to B. Taken together, these results show that glutamine supplementation protects myocardial structure and function after burn injury by improving energy metabolism and by promotedthe synthesis of ATP and GSH in cardiac myocytes. PMID:22977661
Lyu, Lin; Gao, Guodong; Long, Cun
Extracorporeal membrane oxygenation (ECMO) is a kind of technique that uses extracorporeal circulation system to draw patients' blood into the circuit, and then oxygenate the blood when it passes along the membrane, followed by returning the blood into patients. At present, ECMO is mainly used in treating patients with respiratory failure and circulatory failure, for whom the conventional treatment such as mechanical ventilation and vasoactive drugs are invalid. ECMO can provide cardiopulmonary support for burn patients with respiratory failure or circulatory failure, and put the heart and lung at rest. The purpose of this paper is to review the application of ECMO in the treatment of severe burn. PMID:26837253
Jaehn, T; Sievers, R; Junger, A; Graunke, F; Blings, A; Reichert, B
After a motorcycle accident a 16-year-old patient suffered severe burns to 40.5 % of the total body surface area (TBSA) of which 37 % were deep subdermal burns. After tangential and partly epifascial necrosectomy, Integra® was used as a temporary dermis replacement material for the lower extremities, combined with extensive negative pressure wound therapy (NPWT). In the further course of the treatment the patient developed uncontrollable hyperpyrexia with a fatal outcome. Possible influencing factors, such as the dermis replacement material combined with NPWT over large areas as well as the differential diagnoses propofol infusion syndrome, heatstroke and malignant hyperthermia are discussed. PMID:26767381
Mendoza, Antonio; Santoyo, Fernando L; Agulló, Alberto; Fenández-Cañamaque, José L; Vivó, Carmen
Objective: To describe the management of pain prevention associated with burn care. Methods: Multi-centre, observational, cross-sectional, descriptive study performed in 4 burn units in Spain. Results: A total of 55 patients undergoing 64 procedures were analysed. Burns were classified as severe (90.4%), third-degree (78.2%) and caused by thermal agents (81.8%). Background analgesia consisted of non-opioid drugs (87.5%) and opioids (54.7%) [morphine (20.3%), morphine and fentanyl (14.1%) or fentanyl monotherapy (15.6%)]. Burn care was performed by experienced nurses (96.9%); 36.5% followed guidelines. The mean duration of procedures was 44 minutes (Statistical Deviation, SD: 20.2) and the mean duration of pain was 27 minutes (SD: 44.6). Procedural pain was primarily managed with opioid analgesics: fentanyl monotherapy and in combination (84%) and fentanyl monotherapy (48%) administered sublingually (89.1%). Patients described pain as different to usual baseline pain (97%), with a mean maximum intensity score of 4.2 points (SD: 3.3) on the VAS scale and a 34% increase in the intensity of pain. The mean patient and healthcare professional satisfaction score per procedure was 6/10 (SD: 1.9) and 5.5/10 (SD: 1.7), respectively. Conclusion: The results of the study describe the management of pain associated with burn care in clinical practice, helping optimise pain control. PMID:27069760
Genet, H.; Barrett, K. M.; Johnstone, J. F.; McGuire, A. D.; Yuan, F.; Euskirchen, E. S.; Kasischke, E. S.; Rupp, S. T.; Turetsky, M. R.
The fire regime in the boreal region of interior Alaska has been intensifying in terms of both area burned and severity over the last three decades. Based on projections of climate change, this trend is expected to continue throughout the 21st century. Fire causes abrupt changes in energy, nutrient and water balances influencing habitat and vegetation composition. An important factor influencing these changes is the reduction of the soil organic horizon because of differential regeneration capabilities of conifer and evergreen shrubs vs. deciduous and herbaceous vegetation on organic vs. mineral soils. The goal of this study is to develop a prognostic model to simulate the effects of fire severity on soil organic horizons and to evaluate its long-term consequences on forest composition in interior Alaska. Existing field observations were analyzed to build a predictive model of the depth of burning of soil organic horizon after a fire. The model is driven by data sets of fire occurrence, climate, and topography. Post-fire vegetation succession was simulated as a function of post-fire organic horizon depth. The fire severity and post-fire vegetation succession models were then implemented within a biogeochemistry model, the process-based Terrestrial Ecosystem Model. Simulations for 21st century climate scenarios at a 1 by 1km resolution for the Alaska Yukon River Basin were conducted to evaluate the effects of considering vs. ignoring post-fire vegetation succession on carbon dynamics. The results of these simulations indicate that it is important for ecosystem models to represent the influence of fire severity on post-fire vegetation succession in order to fully understand the consequences of changes in climate and disturbance regimes on boreal ecosystems.