Sample records for years post fire

  1. Remote sensing for prediction of 1-year post-fire ecosystem condition

    Treesearch

    Leigh B. Lentile; Alistair M. S. Smith; Andrew T. Hudak; Penelope Morgan; Michael J. Bobbitt; Sarah A. Lewis; Peter R. Robichaud

    2009-01-01

    Appropriate use of satellite data in predicting >1 year post-fire effects requires remote measurement of surface properties that can be mechanistically related to ground measures of post-fire condition. The present study of burned ponderosa pine (Pinus ponderosa) forests in the Black Hills of South Dakota evaluates whether immediate fractional cover estimates of...

  2. Post-fire response of coast redwood one year after the Mendocino lightning complex fires

    Treesearch

    Robert B. Douglas; Tom. Bendurel

    2012-01-01

    Coast redwood (Sequoia sempervirens) forests have undergone significant changes over the past century and are now in state more conducive for wildfires. Because fires have been uncommon in redwood forests over the past 80 years, managers have limited data to make decisions about the post-fire environment. In June 2008, a series of lightning storms...

  3. Post-fire saguaro community: impacts on associated vegetation still apparent 10 years later

    Treesearch

    Marcia Narog; Ruth Wilson

    2005-01-01

    Fire impacts on saguaro (Carnegiea gigantea) associated vegetation were studied in unburned and burned areas over a 10 year post-fire period after the 1993 Vista View fire, Tonto National Forest, Arizona. Many associated species, crucial for saguaro survival, regenerate by vegetative growth after fire. Bushes were the most common nearest-neighbor,...

  4. Fire intensity impacts on post-fire temperate coniferous forest net primary productivity

    NASA Astrophysics Data System (ADS)

    Sparks, Aaron M.; Kolden, Crystal A.; Smith, Alistair M. S.; Boschetti, Luigi; Johnson, Daniel M.; Cochrane, Mark A.

    2018-02-01

    Fire is a dynamic ecological process in forests and impacts the carbon (C) cycle through direct combustion emissions, tree mortality, and by impairing the ability of surviving trees to sequester carbon. While studies on young trees have demonstrated that fire intensity is a determinant of post-fire net primary productivity, wildland fires on landscape to regional scales have largely been assumed to either cause tree mortality, or conversely, cause no physiological impact, ignoring the impacted but surviving trees. Our objective was to understand how fire intensity affects post-fire net primary productivity in conifer-dominated forested ecosystems on the spatial scale of large wildland fires. We examined the relationships between fire radiative power (FRP), its temporal integral (fire radiative energy - FRE), and net primary productivity (NPP) using 16 years of data from the MOderate Resolution Imaging Spectrometer (MODIS) for 15 large fires in western United States coniferous forests. The greatest NPP post-fire loss occurred 1 year post-fire and ranged from -67 to -312 g C m-2 yr-1 (-13 to -54 %) across all fires. Forests dominated by fire-resistant species (species that typically survive low-intensity fires) experienced the lowest relative NPP reductions compared to forests with less resistant species. Post-fire NPP in forests that were dominated by fire-susceptible species were not as sensitive to FRP or FRE, indicating that NPP in these forests may be reduced to similar levels regardless of fire intensity. Conversely, post-fire NPP in forests dominated by fire-resistant and mixed species decreased with increasing FRP or FRE. In some cases, this dose-response relationship persisted for more than a decade post-fire, highlighting a legacy effect of fire intensity on post-fire C dynamics in these forests.

  5. Ten Years of Post-Fire Vegetation Recovery following the 2007 Zaca Fire using Landsat Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Hallett, J. K. E.; Miller, D.; Roberts, D. A.

    2017-12-01

    Forest fires play a key role in shaping eco-systems. The risk to vegetation depends on the fire regime, fuel conditions (age and amount), fire temperature, and physiological characteristics such as bark thickness and stem diameter. The 2007 Zaca Fire (24 kilometers NE of Buellton, Santa Barbara County, California) burned 826.4 km2 over the course of 2 months. In this study, we used a time series of Landsat 5 Thematic Mapper and Landsat 8 Operational Land Imager imagery, to evaluate plant burn severity and post fire recovery as defined into classes of above average recovery, normal recovery, and below average recovery. We spectrally unmixed the images into green vegetation (GV), non-photosynthetic vegetation (NPV), soil surface (SOIL), and ash with a spectral library developed using Constrained Reference Endmember Selection (CRES). We delineated the fire perimeter using the differenced Normalized Burn Ratio (dNBR) and evaluated changes in this index and the Normalized Difference Vegetation Index through time. The results showed an immediate decline in GV and NPV fractions, with a rise in soil and ash fractions directly following the fire, with a slow recovery in GV fraction and a loss of bare soil cover. The was a sharp increase in the ash fraction following the fire and gradual decrease in the year after. Most areas have recovered as of 2017, with prominent recovery in the center of the burn scar and reduced recovery in areas to the south. These results indicate how post-fire vegetation varies based on initial burn severity and pre-fire GV and NPV fractions.

  6. Post-fire Water Quality Response and Associated Physical Drivers

    NASA Astrophysics Data System (ADS)

    Rust, A.; Saxe, S.; Hogue, T. S.; McCray, J. E.; Rhoades, C.

    2017-12-01

    The frequency and severity of forest fires is increasing across the western US. Wildfires are known to impact water quality in receiving waters; many of which are important sources of water supply. Studies on individual forest fires have shown an increase in total suspended solids, nutrient and metal concentrations and loading in receiving streams. The current research looks at a large number of fires across a broad region (Western United States) to identify typical water quality changes after fire and the physical characteristics that drive those responses. This presentation will overview recent development of an extensive database on post-fire water quality. Across 172 fires, we found that water quality changed significantly in one out of three fires up to five years after the event compared to pre-burn conditions. For basins with higher frequency data, it was evident that water quality changes were significant in the first three years following fire. In both the initial years following fire and five years after fire, concentrations and loading rates of dissolved nutrients such as nitrite, nitrate and orthophosphate and particulate forms of nutrients, total organic nitrogen, total nitrogen, total phosphate, and total phosphorus increase thirty percent of the time. Concentrations of some major dissolved ions and metals decrease, with increased post-fire flows, while total particulate concentrations increased; the flux of both dissolved and particulate forms increase in thirty percent of the fires over five years. Water quality change is not uniform across the studied watersheds. A second goal of this study is to identify physical characteristics of a watershed that drive water quality response. Specifically, we investigate the physical, geochemical, and climatological characteristics of watersheds that control the type, direction, and magnitude of water quality change. Initial results reveal vegetation recovery is a key driver in post-fire water quality response

  7. Post-fire treatment effectiveness for hillslope stabilization

    Treesearch

    Peter R. Robichaud; Louise E. Ashmun; Bruce D. Sims

    2010-01-01

    This synthesis of post-fire treatment effectiveness reviews the past decade of research, monitoring, and product development related to post-fire hillslope emergency stabilization treatments, including erosion barriers, mulching, chemical soil treatments, and combinations of these treatments. In the past ten years, erosion barrier treatments (contour-felled logs and...

  8. FEMME- post-Fire Emergency ManageMEnt tool.

    NASA Astrophysics Data System (ADS)

    Vieira, Diana; Serpa, Dalila; Rocha, João; Nunes, João; Keizer, Jacob

    2017-04-01

    Wildfires can have important impacts on hydrological and soil erosion processes in forest catchments, due to the destruction of vegetation cover and changes to soil properties. The involved processes however, are non-linear and not fully understood. This has severely limited the understanding on the impacts of wildfires, and, as a consequence, current runoff-erosion models are poorly adapted to recently burned forest conditions. Furthermore, while post-fire forestry operations and, to a lesser extent, post-fire soil conservation measures are commonly applied, their hydrological and erosion impacts continue poorly known, hampering decision-making by land owners and managers. Past post-wildfire research in Portugal has involved simple adaptations of plot-scale runoff-erosion models to post-fire conditions. This follow-up study focusses on model adaptation to selected post-fire soil conservation measures. To this end, full stock is taken of various datasets collected by several (past and ongoing research projects. The selected model is the Morgan-Morgan-Finney model (MMF, Morgan,2001), which already proved its suitability for post-fire conditions in Portugal (Vieira et al, 2010, 2014) as well as NW-Spain ( Fernández et al., 2010). The present results concerned runoff and erosion different burn severities and various post-fire mitigation treatments (mulch, hydromulch, needle cast, barriers), focussing on the plot and field scale. The results for both the first and the second year following the wildfire revealed good model efficiency, not only for burned and untreated conditions but also for burned and treated conditions. These results thus reinforced earlier findings that MMF is a suitable model for the envisaged post-fire soil erosion assessment tool, coined "FEMME". The data used for post-fire soil erosion calibration with the MMF already allows the delineation of the post-fire management FEMME tool. Nevertheless, further model assessment will address additional

  9. Landscape variation in tree regeneration and snag fall drive fuel loads in 24-year old post-fire lodgepole pine forests.

    PubMed

    Nelson, Kellen N; Turner, Monica G; Romme, William H; Tinker, Daniel B

    2016-12-01

    Escalating wildfire in subalpine forests with stand-replacing fire regimes is increasing the extent of early-seral forests throughout the western USA. Post-fire succession generates the fuel for future fires, but little is known about fuel loads and their variability in young post-fire stands. We sampled fuel profiles in 24-year-old post-fire lodgepole pine (Pinus contorta var. latifolia) stands (n = 82) that regenerated from the 1988 Yellowstone Fires to answer three questions. (1) How do canopy and surface fuel loads vary within and among young lodgepole pine stands? (2) How do canopy and surface fuels vary with pre- and post-fire lodgepole pine stand structure and environmental conditions? (3) How have surface fuels changed between eight and 24 years post-fire? Fuel complexes varied tremendously across the landscape despite having regenerated from the same fires. Available canopy fuel loads and canopy bulk density averaged 8.5 Mg/ha (range 0.0-46.6) and 0.24 kg/m 3 (range: 0.0-2.3), respectively, meeting or exceeding levels in mature lodgepole pine forests. Total surface-fuel loads averaged 123 Mg/ha (range: 43-207), and 88% was in the 1,000-h fuel class. Litter, 1-h, and 10-h surface fuel loads were lower than reported for mature lodgepole pine forests, and 1,000-h fuel loads were similar or greater. Among-plot variation was greater in canopy fuels than surface fuels, and within-plot variation was greater than among-plot variation for nearly all fuels. Post-fire lodgepole pine density was the strongest positive predictor of canopy and fine surface fuel loads. Pre-fire successional stage was the best predictor of 100-h and 1,000-h fuel loads in the post-fire stands and strongly influenced the size and proportion of sound logs (greater when late successional stands had burned) and rotten logs (greater when early successional stands had burned). Our data suggest that 76% of the young post-fire lodgepole pine forests have 1,000-h fuel loads that exceed levels

  10. Predicting post-fire tree mortality for 12 western US conifers using the First-Order Fire Effects Model (FOFEM)

    Treesearch

    Sharon Hood; Duncan Lutes

    2017-01-01

    Accurate prediction of fire-caused tree mortality is critical for making sound land management decisions such as developing burning prescriptions and post-fire management guidelines. To improve efforts to predict post-fire tree mortality, we developed 3-year post-fire mortality models for 12 Western conifer species - white fir (Abies concolor [Gord. &...

  11. [Research progress in post-fire debris flow].

    PubMed

    Di, Xue-ying; Tao, Yu-zhu

    2013-08-01

    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.

  12. Modeling post-fire hydro-geomorphic recovery in the Waldo Canyon Fire

    NASA Astrophysics Data System (ADS)

    Kinoshita, Alicia; Nourbakhshbeidokhti, Samira; Chin, Anne

    2016-04-01

    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.

  13. Post-fire surface fuel dynamics in California forests across three burn severity classes

    Treesearch

    Bianca N. I. Eskelson; Vicente J. Monleon

    2018-01-01

    Forest wildfires consume fuel and are followed by post-fire fuel accumulation. This study examines post-fire surface fuel dynamics over 9 years across a wide range of conditions characteristic of California fires in dry conifer and hardwood forests. We estimated post-fire surface fuel loadings (Mg ha _1) from 191 repeatedly measured United States...

  14. Post-fire hydrologic response in Central Portugal. A four years study at microplot scale.

    NASA Astrophysics Data System (ADS)

    Vieira, Diana; Malvar, Maruxa; Martins, Martinho; Machado, Ana; Nunes, João; Keizer, Jacob

    2014-05-01

    Wildfires are a natural phenomenon in regions with a Mediterranean-type climate. However, their present-day widespread occurrence in southern Europe is unprecedented and strongly reflects human activity such as ignition, land-use changes, land abandonment and introduction of highly flammable plantations. Besides wildfires, post-fire management practices such as plowing, terracing, clearcutting and logging should also be considered, since their occurrence is getting increasingly common. And, in a long-term period these practices seem to be executed intercalated with repeated fire occurrences in the same site, sharing the impacts together with fire in an escalated degradational effect. In this sense, the work presented here concerns four years of runoff and erosion data at microplot scale after the wildfire, comparing different land management practices that occurred before the fire. Preliminary results indicate that in four years of monitoring, runoff is constantly higher in plowed sites than in the unplowed ones, with the exception of the first year. Regarding soil losses the plowed plots present always higher sediment rates than the unplowed ones. The comparison between two unplowed sites with different land uses, indicate higher runoff and erosion risk for pine comparatively to the eucalypt ones, however the reduced soil depth in the first can have an important role in these differences. Following these facts, the aim of the present work is to answer the following research questions: i) Do these four years of observations fit with the window of disturbance model presented by Prosser and Williams (1998). or the alternative version by Wittenberg and Inbar (2009)?; ii) Does pre-fire disturbances (wildfire, land use changes and land management practices) still have repercussions after wildfire?; In what sense does four years of intensive monitoring provides that one year couldn't provide?

  15. The effects of fire severity on black carbon additions to forest soils - 10 years post fire

    NASA Astrophysics Data System (ADS)

    Poore, R.; Wessman, C. A.; Buma, B.

    2013-12-01

    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%.

  16. Post-Fire Recovery in Coastal Sage Scrub: Seed Rain and Community Trajectory.

    PubMed

    Conlisk, Erin; Swab, Rebecca; Martínez-Berdeja, Alejandra; Daugherty, Matthew P

    2016-01-01

    Disturbance is a primary mechanism structuring ecological communities. However, human activity has the potential to alter the frequency and intensity of natural disturbance regimes, with subsequent effects on ecosystem processes. In Southern California, human development has led to increased fire frequency close to urban areas that can form a positive feedback with invasive plant spread. Understanding how abiotic and biotic factors structure post-fire plant communities is a critical component of post-fire management and restoration. In this study we considered a variety of mechanisms affecting post-fire vegetation recovery in Riversidean sage scrub. Comparing recently burned plots to unburned plots, we found that burning significantly reduced species richness and percent cover of exotic vegetation the first two years following a 100-hectare wildfire. Seed rain was higher in burned plots, with more native forb seeds, while unburned plots had more exotic grass seeds. Moreover, there were significant correlations between seed rain composition and plant cover composition the year prior and the year after. Collectively, this case study suggests that fire can alter community composition, but there was not compelling evidence of a vegetation-type conversion. Instead, the changes in the community composition were temporary and convergence in community composition was apparent within two years post-fire.

  17. Post-fire recovery of torpor and activity patterns of a small mammal.

    PubMed

    Stawski, Clare; Hume, Taylor; Körtner, Gerhard; Currie, Shannon E; Nowack, Julia; Geiser, Fritz

    2017-05-01

    To cope with the post-fire challenges of decreased availability of food and shelter, brown antechinus ( Antechinus stuartii ), a small marsupial mammal, increase the use of energy-conserving torpor and reduce activity. However, it is not known how long it takes for animals to resume pre-fire torpor and activity patterns during the recovery of burnt habitat. Therefore, we tested the hypothesis that antechinus will adjust torpor use and activity after a fire depending on vegetation recovery. We simultaneously quantified torpor and activity patterns for female antechinus from three adjacent areas: (i) the area of a management burn 1 year post-fire, (ii) an area that was burned 2 years prior, and (iii) a control area. In comparison to shortly after the management burn, antechinus in all three groups displayed less frequent and less pronounced torpor while being more active. We provide the first evidence that only 1 year post-fire antechinus resume pre-fire torpor and activity patterns, probably in response to the return of herbaceous ground cover and foraging opportunities. © 2017 The Author(s).

  18. Post Fire Vegetation Recovery in Portugal

    NASA Astrophysics Data System (ADS)

    Gouveia, Celia; Bastos, Ana; DaCamara, Carlos; Trigo, Ricardo M.

    2011-01-01

    Fires in Portugal, as in the Mediterranean ecosystems, have a complex effect on vegetation regeneration due to the different responses of vegetation to the variety of fire regimes and to the complexity of landscape structures. A thorough evaluation of vegetation recovery after fire events becomes therefore crucial in land management. In 2005, Portugal suffered a strong damage from forest fires that damaged an area of 300 000 ha of forest and shrub. This year are particularly interesting because it is associated the severe drought of 2005. The aim of the present study is to identify large burnt scars in Portugal during the 2005 fire seasons and monitoring vegetation behaviour throughout the pre and the post fire periods. The mono-parametric model developed by Gouveia et al. (2010), based on monthly values of NDVI, at the 1km×1km spatial scale, as obtained from the VEGETATION-SPOT5 instrument, from 1999 to 2009, was used.

  19. Avian community responses to post-fire forest structure: Implications for fire management in mixed conifer forests

    USGS Publications Warehouse

    White, Angela M.; Manley, Patricia N.; Tarbill, Gina; Richardson, T.L.; Russell, Robin E.; Safford, Hugh D.; Dobrowski, Solomon Z.

    2015-01-01

    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.

  20. Post-fire regeneration across a fire severity gradient in the southern Cascades

    Treesearch

    Justin Crotteau; Morgan Varner; Martin Ritchie

    2012-01-01

    Large scale, high-severity fires are increasing in the western United States. Despite this trend, there have been few studies investigating post-fire tree regeneration. We established a study in the footprint of the 2000 Storrie Fire, a 23,000 ha wildfire that occurred in northern California, USA. We used a stratified sampling design to quantify post-fire vegetation...

  1. Post-fire regeneration in a Mediterranean pine forest with historically low fire frequency

    NASA Astrophysics Data System (ADS)

    Buhk, Constanze; Götzenberger, Lars; Wesche, Karsten; Gómez, Pedro Sánchez; Hensen, Isabell

    2006-11-01

    Species of Mediterranean vegetation are known to regenerate directly after fire. The phenomenon of autosuccession (direct regeneration) has been found to be often combined with an increase of species richness during the first years after fire due to the high abundance of short-lived herbaceous plants facilitated by plentiful nutrients and light. The high degree of vegetation resilience, which is expressed in terms of autosuccession, has been explained by the selective pressure of fire in historic times. According to existing palaeoecological data, however, the Pinus halepensis forests in the Ricote Mountains (Province of Murcia, SE Spain) did not experience substantial fire impact before the presence of man nor are they especially fire-prone today. Therefore, we studied post-fire regeneration to find out if direct succession is present or if species from pre-fire vegetation are absent during the post-fire regeneration stages. Patterns of succession were deduced from observations made in sample plots on sites of a known regeneration age as well as in adjacent unburnt areas. The results of the vegetation analyses, including a Detrended Correspondence Analysis, indicate that Pinus halepensis forest regeneration after fire resembles autosuccession. As regards the presence of woody species, there is a high percentage similarity on north (83%) and south (70%) facing slopes during the first year after fire vs. reference areas which is due, for example, to direct regeneration of the resprouting Quercus coccifera or seeders like Pinus halepensis or Fumana laevipes. However, if herbaceous species are included in the comparison, the similarity on north-facing sites decreases (to 53%) with the presence of additional species, mainly ruderals like Anagallis arvensis or Reseda phyteuma, and even woody species on the burnt plots. This effect indicates "enhanced autosuccession", which was not found on south-facing sites where overall species richness was very high irrespective of

  2. Hydrogeological controls on post-fire moss recovery in peatlands

    NASA Astrophysics Data System (ADS)

    Lukenbach, M. C.; Devito, K. J.; Kettridge, N.; Petrone, R. M.; Waddington, J. M.

    2015-11-01

    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

  3. Post-fire tree stress and growth following smoldering duff fires

    Treesearch

    Morgan Varner; Francis E. Putz; Robert J. Mitchell; J. Kevin Hiers; Joseph J. O’Brien; Doria R. Gordon

    2009-01-01

    Understanding the proximate causes of post-fire conifer mortality due to smoldering duff fires is essential to the restoration and management of coniferous forests throughout North America. To better understand duff fire-caused mortality, we investigated tree stress and radial growth following experimental fires in a long-unburned forest on deep sands in northern...

  4. Post-fire land treatments and wind erosion -- lessons from the Milford Flat Fire, UT, USA

    USGS Publications Warehouse

    Miller, Mark E.; Bowker, Matthew A.; Reynolds, Richard L.; Goldstein, Harland L.

    2012-01-01

    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.

  5. Monitoring post-fire recovery of shrublands in Mediterranean-type ecosystems using MODIS and TM/ETM+ data

    NASA Astrophysics Data System (ADS)

    Hope, Allen; Albers, Noah; Bart, Ryan

    2010-05-01

    Wildland fires in Mediterranean-Type Ecosystems (MTEs) are episodic events that dramatically alter land-cover conditions. Monitoring post-fire vegetation recovery is important for land management applications such as the scheduling of prescribed burns, post-fire resource management and soil erosion control. Full recovery of MTE shrublands may take many years and have a prolonged effect on water, energy and carbon fluxes in these ecosystems. Comparative studies of fynbos ecosystems in the Cape Floristic Region of South Africa (Western Cape Region) and chaparral ecosystems of California have demonstrated that there is a considerable degree of convergence in some aspects of post-fire vegetation regeneration and marked differences in other aspects. Since these MTEs have contrasting rainfall and soil nutrient conditions, an obvious question arises as to the similarity or dissimilarity in remotely sensed post-fire recovery pathways of vegetation stands in these two regions and the extent to which fire severity and drought impact the rate of vegetation recovery. Post-fire recovery pathways of chaparral and fynbos vegetation stands were characterized using the normalized difference vegetation index (NDVI) based on TM/ETM+ and MODIS (250 m) data. Procedures based on stands of unburned vegetation (control) were implemented to normalize the NDVI for variations associated with inter-annual differences in rainfall. Only vegetation stands that had not burned for 20 years were examined in this study to eliminate potential effects of variable fire histories on the recovery pathways. Post-fire recovery patterns of vegetation in both regions and across different vegetation types were found to be very similar. Post-fire stand age was the primary control over vegetation recovery and the NDVI returned to pre-fire values within seven to 10 years of the fires. Droughts were shown to cause slight interruptions in recovery rates while fire severity had no discernable effect. Intra

  6. Catchment-scale Validation of a Physically-based, Post-fire Runoff and Erosion Model

    NASA Astrophysics Data System (ADS)

    Quinn, D.; Brooks, E. S.; Robichaud, P. R.; Dobre, M.; Brown, R. E.; Wagenbrenner, J.

    2017-12-01

    The cascading consequences of fire-induced ecological changes have profound impacts on both natural and managed forest ecosystems. Forest managers tasked with implementing post-fire mitigation strategies need robust tools to evaluate the effectiveness of their decisions, particularly those affecting hydrological recovery. Various hillslope-scale interfaces of the physically-based Water Erosion Prediction Project (WEPP) model have been successfully validated for this purpose using fire-effected plot experiments, however these interfaces are explicitly designed to simulate single hillslopes. Spatially-distributed, catchment-scale WEPP interfaces have been developed over the past decade, however none have been validated for post-fire simulations, posing a barrier to adoption for forest managers. In this validation study, we compare WEPP simulations with pre- and post-fire hydrological records for three forested catchments (W. Willow, N. Thomas, and S. Thomas) that burned in the 2011 Wallow Fire in Northeastern Arizona, USA. Simulations were conducted using two approaches; the first using automatically created inputs from an online, spatial, post-fire WEPP interface, and the second using manually created inputs which incorporate the spatial variability of fire effects observed in the field. Both approaches were compared to five years of observed post-fire sediment and flow data to assess goodness of fit.

  7. Factors affecting plant diversity during post-fire recovery and succession of mediterranean-climate shrublands in California, USA

    USGS Publications Warehouse

    Keeley, J.E.; Fotheringham, C.J.; Baer-Keeley, M.

    2005-01-01

    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.

  8. Post-Fire Peat Land Understory Plant in Rimba Panjang, Sumatera, Indonesia

    NASA Astrophysics Data System (ADS)

    Firdaus, L. N.; Nursal; Wulandari, Sri; Syafi'i, Wan; Fauziah, Yuslim

    2017-12-01

    The existence of understory plants during early post-fire succession is essential in term of natural post-fire ecological restoration. More than fifty percent of fire incidents in Riau, Sumatera, Indonesia occurred in shallow peat lands which have the huge impact on vegetation damage. This study aims to explore the understory plants species and diversity in post-fire peat land at Rimba Panjang, Kampar Regency, Sumatera, Indonesia. By using survey method, the observations were conducted on 150 plots which were distributed randomly over four locations based on the year after fire: 2009, 2014, 2015 and 2016. We found respectively 12, 14, 19 and 17 species at that sites with respective Shannon Wiener diversity index were 1.72, 2.00, 2.14 and 2.40. All the sites were dominated by Stenochlaena palustris (Burm.). Coverage percentage of understory vegetation were respectively 28.87%, 25.50%, 51.60% and 54.13%. Overall, we found 31 species of 17 familia. The result showed that the species composition, diversity index and coverage percentage of understory plant are likely to decrease in line with the length of time after the fire. Post peatland fires in Rimba Panjang are still having the characteristics of the peat swamp habitat which was dominated by Stenochlaena palustris (Burm.). Ecological restoration of that habitat is still possible, but it is necessary to consider technological and socio-economical aspects of local communities.

  9. The helminth community component species of the wood mouse as biological tags of a ten post-fire-year regeneration process in a Mediterranean ecosystem.

    PubMed

    Sáez-Durán, Sandra; Debenedetti, Ángela L; Sainz-Elipe, Sandra; Galán-Puchades, M Teresa; Fuentes, Màrius V

    2018-05-10

    Serra Calderona Natural Park, a Mediterranean ecosystem, has been in post-fire regeneration for 10 years. To elucidate which helminth community component species of the wood mouse, Apodemus sylvaticus, can be considered biological tags of this process, the influence of intrinsic (host density; host sex and age) and extrinsic factors (site, year, and period of capture; vegetation recovery) on their prevalence and abundance has been analysed, comparing a burned and an unburned area. A total of 564 wood mice (408 from the burned and 156 from the unburned area), from the 2nd to the10th post-fire year, was included in this helminthoecological study. The results suggest that the area in post-fire regeneration is still more vulnerable to periodic environmental changes than the unburned area as deduced from the analysis of the helminth populations of Pseudocatenotaenia matovi, Skrjabinotaenia lobata, Trichuris muris, Eucoleus bacillatus and Aonchotheca annulosa. The intermediate and definitive host populations presented a greater variability to these environmental changes in the burned area (Taenia parva, P. matovi, S. lobata, A. annulosa, Syphacia stroma and S. frederici). In the regenerating area, some behavioural changes in certain populations determined by the host sex are taking place (T. parva, Helgimosomoides polygyrus and S. frederici). During the last years studied, a greater similarity in the populational development of some component species between both areas can be appreciated (H. polygyrus and S. stroma). The role of the wood mouse and its helminth parasites as biological tags of the post-fire regeneration process in Mediterranean ecosystems has been confirmed.

  10. Post-fire vegetation behaviour in large burnt scars from 2005 fire season in Spain

    NASA Astrophysics Data System (ADS)

    Bastos, A.; Gouveia, C. M.; DaCamara, C. C.; Trigo, R. M.

    2012-04-01

    remaining areas (centre and south), vegetation recovered very slowly and irregularly. Four years following the fire, vegetation density in these two scars was still markedly below pre-fire levels. Spatial patterns of recovery times were assessed in order to evaluate the influence of physical factors such as fire damage, pre-fire vegetation density and land-cover type, in post-fire behaviour of vegetation for each scar. Pre-fire land-cover type raised as a key factor that may partially explain the differences observed, with shrublands and mixed forests recovering faster than coniferous. Gouveia C., DaCamara C.C. and Trigo R.M.: Post fire vegetation recovery in Portugal based on SPOT-VEGETATION data, Natural Hazards and Earth System Sciences, 10, 673-684, 2010. Viedma, O., Moreno, J.M. and Rieiro, I.: Interactions between land use/land cover change, forest fires and landscape structure in Sierra de Gredos (central Spain), Environmental Conservation, 33, 212-222, 2006.

  11. Post-fire vegetation dynamics in Portugal

    NASA Astrophysics Data System (ADS)

    Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

    2009-04-01

    The number of fires and the extent of the burned surface in Mediterranean Europe have increased significantly during the last three decades. This may be due either to modifications in land-use (e.g. land abandonment and fuel accumulation) or to climatic changes (e.g. reduction of fuel humidity), both factors leading to an increase of fire risk and fire spread. As in the Mediterranean ecosystems, fires in Portugal have an intricate effect on vegetation regeneration due to the complexity of landscape structures as well as to the different responses of vegetation to the variety of fire regimes. A thorough evaluation of vegetation recovery after fire events becomes therefore crucial in land management. In the above mentioned context remote sensing plays an important role because of its ability to monitor and characterise post-fire vegetation dynamics. A number of fire recovery studies, based on remote sensing, have been conducted in regions characterised by Mediterranean climates and the use of NDVI to monitor plant regeneration after fire events was successfully tested (Díaz-Delgado et al., 1998). In particular, several studies have shown that rapid regeneration occurs within the first 2 years after the fire occurrences, with distinct recovery rates according to the geographical facing of the slopes (Pausas and Vallejo, 1999). In 2003 Portugal was hit by the most devastating sequence of large fires, responsible by a total burnt area of 450 000 ha (including 280 000 ha of forest), representing about 5% of the Portuguese mainland (Trigo et al., 2006). The aim of the present work is to assess and monitor the vegetation behaviour over Portugal following the 2003 fire episodes. For this purpose we have used the regional fields of the Normalized Difference Vegetation Index (NDVI) as obtained from the VEGETATION-SPOT5 instrument, from 1999 to 2008. We developed a methodology to identify large burnt scars in Portugal for the 2003 fire season. The vegetation dynamics was then

  12. Assessment of Fire Severity and Post-Fire Regeneration Based on Topographical Features Using Multitemporal Landsat Imagery: a Case Study in Mersin, Turkey

    NASA Astrophysics Data System (ADS)

    Tonbul, H.; Kavzoglu, T.; Kaya, S.

    2016-06-01

    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.

  13. Remote sensing techniques to assess active fire characteristics and post-fire effects

    Treesearch

    Leigh B. Lentile; Zachary A. Holden; Alistair M. S. Smith; Michael J. Falkowski; Andrew T. Hudak; Penelope Morgan; Sarah A. Lewis; Paul E. Gessler; Nate C. Benson

    2006-01-01

    Space and airborne sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. Confusion about fire intensity, fire severity, burn severity, and related terms can result in the potential misuse of the inferred information by land managers and remote sensing practitioners who require unambiguous...

  14. Drought differentially affects the post-fire dynamics of seeders and resprouters in a Mediterranean shrubland.

    PubMed

    Parra, Antonio; Moreno, José M

    2018-06-01

    In fire-prone ecosystems, changes in rainfall after fire could differentially affect seeders and resprouters, thus leading to long-lasting impacts on the vegetation. Climate change in the Mediterranean region is projected to reduce precipitation, expand the summer drought and increase fire danger. Understanding the sensitivity to changes in rainfall during the post-fire regeneration stage is critical to anticipate the impacts of climate change on Mediterranean-type areas of the world. Here, we investigated how species differing in post-fire regeneration strategy (seeders vs resprouters) responded to rainfall changes in a Cistus-Erica shrubland of central Spain. Drought treatments were implemented using a system of automatic rainout shelters with an irrigation facility before (one season) and after (four years) burning a set of experimental plots. Treatments applied were: environmental control (natural rainfall), historical control (mimicking the long-term rainfall), moderate drought (-25% rainfall), and severe drought (-45% rainfall). Plant demography and vigour (main woody shrubs), as well as abundance (shrubs and herbs) were monitored during the first four years after fire. The first post-fire year was the key period for the recovery of seeders (Cistus ladanifer and Rosmarinus officinalis), and their recruitment, cover and size significantly decreased with drought. However, density four years after fire was larger than unburned and it was significantly correlated with emergence during the first year, indicating that population controls were more on emergence than on establishment. In contrast, resprouters (Erica arborea, Erica scoparia and Phillyrea angustifolia) were hardly affected by drought. Plant community dynamics in the burned control plots progressively converged with the unburned ones, while that in the drought-treated plots lagged behind them, maintaining a higher cover, richness and diversity of herbs. This post-fire "herbalization" due to drought

  15. Post-fire vegetation succession in Mediterranean gorse shrublands

    NASA Astrophysics Data System (ADS)

    De Luis, Martin; Raventós, José; González-Hidalgo, José Carlos

    2006-07-01

    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

  16. Early post-fire succession in California chaparral: changes in diversity, density, cover, and biomass

    USGS Publications Warehouse

    Guo, Q.

    2001-01-01

    For four consecutive years, following the fires in November 1993, temporal variations in species richness, cover and biomass of component plant groups in early post-fire chaparral succession were monitored on different aspects at the Stunt Ranch Santa Monica Mountains Reserve, southern California. Plant groups were categorized based on growth form, life form, ability to fix nitrogen, geographic origin and regeneration strategies. North-facing slopes exhibited higher species richness, higher species turnover rate over time and faster vegetation recovery in terms of biomass accumulation and return to pre-fire species composition. This was probably due to higher species richness and biomass of nitrogen-fixing species found on north-facing slopes in comparison to south-facing slopes. On both north- and south-facing slopes, annuals had the highest species turnover rate, followed by herbaceous perennials and shrubs. In the first four post-fire years, annual species were the largest floristic group, but herbaceous perennials and shrubs were the major contributors to community biomass. Nitrogen-fixing species and exotics contributed significantly to early post-fire community structure. Although the general trends in post-fire succession are clear in terms of temporal changes in the relative proportions of different plant groups, environmental variation and the nature of plant life histories of component species, especially dominant species, could alter such trends significantly.

  17. Early post-fire succession in California chaparral: Changes in diversity, density, cover and biomass

    USGS Publications Warehouse

    Guo, Q.

    2001-01-01

    For four consecutive years, following the fires in November 1993, temporal variations in species richness, cover and biomass of component plant groups in early post-fire chaparral succession were monitored on different aspects at the Stunt Ranch Santa Monica Mountains Reserve, southern California. Plant groups were categorized based on growth form, life form, ability to fix nitrogen, geographic origin and regeneration strategies. North-facing slopes exhibited higher species richness, higher species turnover rate over time and faster vegetation recovery in terms of biomass accumulation and return to pre-fire species composition. This was probably due to higher species richness and biomass of nitrogen-fixing species found on north-facing slopes in comparison to south-facing slopes. On both north- and south-facing slopes, annuals had the highest species turnover rate, followed by herbaceous perennials and shrubs. In the first four post-fire years, annual species were the largest floristic group, but herbaceous perennials and shrubs were the major contributors to community biomass. Nitrogen-fixing species and exotics contributed significantly to early post-fire community structure. Although the general trends in post-fire succession are clear in terms of temporal changes in the relative proportions of different plant groups, environmental variation and the nature of plant life histories of component species, especially dominant species, could alter such trends significantly.

  18. Index for characterizing post-fire soil environments in temperate coniferous forests

    USGS Publications Warehouse

    Jain, Theresa B.; Pilliod, David S.; Graham, Russell T.; Lentile, Leigh B.; Sandquist, Jonathan E.

    2012-01-01

    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.

  19. Post-fire vegetation recovery in Portugal based on spot/vegetation data

    NASA Astrophysics Data System (ADS)

    Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

    2010-04-01

    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.

  20. Post-fire Water Quality in the Western United States: Understanding and Predicting Short and Long-term Response

    NASA Astrophysics Data System (ADS)

    Hogue, T. S.; Rust, A.

    2016-12-01

    Fire frequency is increasing across mid-elevation forests, especially in the Northern Rockies, Sierra Nevada, southern Cascades, as well as the coastal ranges in California and southern Oregon. Numerous studies have noted increased discharge, floods and debris flows after wildfire. More recent work also shows increased water yield during dry seasons for up to ten years post-fire. However, few studies have evaluated long-term water quality response in fire-impacted watersheds. The current presentation will overview recent development of an extensive database on post-fire water quality response across the western U.S. A range of water quality parameters were gathered from 271 burned watersheds through local, state and federal agencies. Short and long-term response was evaluated for watersheds with at least 5 years of pre-fire data. Over 30 watersheds showed significant increases in NO3-, NO2-, NH3, and total nitrogen loading in the initial five years after fire and remained elevated ten years after fire. The burn severity influenced the degree of nitrogen response, where more severely burned watersheds showed higher nitrogen loading than less severely burned watersheds. Dissolved and total phosphorous showed significant increases in 32 watersheds for the first five years after fire. Dissolved ions such as calcium, magnesium, and chloride were also exported from over 32 watersheds, primarily during the first five years after fire, with the majority of impacted watersheds returning to pre-fire water quality conditions after ten years. Ongoing work includes evaluating key determinants that drive short and long-term response and developing predictive models for post-fire water quality. Watersheds impacted by wildfire are known to pose significant risks for downstream communities. Understanding short and long-term water quality change that can impact regional water supplies is critical for establishing potential treatment priorities and alternative source planning.

  1. ERMiT: Estimating Post-Fire Erosion in Probabilistic Terms

    NASA Astrophysics Data System (ADS)

    Pierson, F. B.; Robichaud, P. R.; Elliot, W. J.; Hall, D. E.; Moffet, C. A.

    2006-12-01

    Mitigating the impact of post-wildfire runoff and erosion on life, property, and natural resources have cost the United States government tens of millions of dollars over the past decade. The decision of where, when, and how to apply the most effective 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) is a web-based application that estimates erosion in probabilistic terms on burned and recovering forest, range, and chaparral lands. Unlike most erosion prediction models, ERMiT does not provide `average annual erosion rates;' rather, it provides a distribution of erosion rates with the likelihood of their occurrence. ERMiT combines rain event variability with spatial and temporal variabilities of hillslope burn severity, soil properties, and ground cover to estimate Water Erosion Prediction Project (WEPP) model input parameter values. Based on 20 to 40 individual WEPP runs, ERMiT produces a distribution of rain event erosion rates with a probability of occurrence for each of five post-fire years. Over the 5 years of modeled recovery, the occurrence probability of the less erodible soil parameters is increased and the occurrence probability of the more erodible soil parameters is decreased. In addition, the occurrence probabilities and the four spatial arrangements of burn severity (arrangements of overland flow elements (OFE's)), are shifted toward lower burn severity with each year of recovery. These yearly adjustments are based on field measurements made through post-fire recovery periods. ERMiT also provides rain event erosion rate distributions for hillslopes that have been treated with seeding, straw mulch, straw wattles and contour-felled log erosion barriers. Such output can help managers make erosion mitigation treatment decisions based on the probability of high sediment yields occurring, the value of resources at risk for damage, cost, and

  2. Mid-term and scaling effects of forest residue mulching on post-fire runoff and soil erosion.

    PubMed

    Prats, Sergio Alegre; Wagenbrenner, Joseph W; Martins, Martinho António Santos; Malvar, Maruxa Cortizo; Keizer, Jan Jacob

    2016-12-15

    Mulching is an effective post-fire soil erosion mitigation treatment. Experiments with forest residue mulch have demonstrated that it increased ground cover to 70% and reduced runoff and soil loss at small spatial scales and for short post-fire periods. However, no studies have systematically assessed the joint effects of scale, time since burning, and mulching on runoff, soil loss, and organic matter loss. The objective of this study was to evaluate the effects of scale and forest residue mulch using 0.25m 2 micro-plots and 100m 2 slope-scale plots in a burnt eucalypt plantation in central Portugal. We assessed the underlying processes involved in the post-fire hydrologic and erosive responses, particularly the effects of soil moisture and soil water repellency. Runoff amount in the micro-plots was more than ten-fold the runoff in the larger slope-scale plots in the first year and decreased to eight-fold in the third post-fire year. Soil losses in the micro-plots were initially about twice the values in the slope-scale plots and this ratio increased over time. The mulch greatly reduced the cumulative soil loss measured in the untreated slope-scale plots (616gm -2 ) by 91% during the five post-fire years. The implications are that applying forest residue mulch immediately after a wildfire can reduce soil losses at spatial scales of interest to land managers throughout the expected post-fire window of disturbance, and that mulching resulted in a substantial relative gain in soil organic matter. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Quantifying post-fire fallen trees using multi-temporal lidar

    NASA Astrophysics Data System (ADS)

    Bohlin, Inka; Olsson, Håkan; Bohlin, Jonas; Granström, Anders

    2017-12-01

    Massive tree-felling due to root damage is a common fire effect on burnt areas in Scandinavia, but has so far not been analyzed in detail. Here we explore if pre- and post-fire lidar data can be used to estimate the proportion of fallen trees. The study was carried out within a large (14,000 ha) area in central Sweden burnt in August 2014, where we had access to airborne lidar data from both 2011 and 2015. Three data-sets of predictor variables were tested: POST (post-fire lidar metrics), DIF (difference between post- and pre-fire lidar metrics) and combination of those two (POST_DIF). Fractional logistic regression was used to predict the proportion of fallen trees. Training data consisted of 61 plots, where the number of fallen and standing trees was calculated both in the field and with interpretation of drone images. The accuracy of the best model was tested based on 100 randomly selected validation plots with a size of 25 × 25 m. Our results showed that multi-temporal lidar together with field-collected training data can be used for quantifying post-fire tree felling over large areas. Several height-, density- and intensity metrics correlated with the proportion of fallen trees. The best model combined metrics from both datasets (POST_DIF), resulting in a RMSE of 0.11. Results were slightly poorer in the validation plots with RMSE of 0.18 using pixel size of 12.5 m and RMSE of 0.15 using pixel size of 6.25 m. Our model performed least well for stands that had been exposed to high-intensity crown fire. This was likely due to the low amount of echoes from the standing black tree skeletons. Wall-to-wall maps produced with this model can be used for landscape level analysis of fire effects and to explore the relationship between fallen trees and forest structure, soil type, fire intensity or topography.

  4. Fire timing in relation to masting: an important determinant of post-fire recruitment success for the obligate-seeding arid zone soft spinifex (Triodia pungens).

    PubMed

    Wright, Boyd R; Fensham, Roderick J

    2018-01-25

    Plant species with fire-triggered germination are common in many fire-prone ecosystems. For such plants, fire timing in relation to the timing of reproduction may strongly influence post-fire population regeneration if: (a) flowering occurs infrequently (e.g. plants are mast seeders); and (b) seed survival rates are low and input from the current year's flowering therefore contributes a large proportion of the viable dormant seedbank. The role of fire timing in relation to masting as a driver of post-fire recruitment has rarely been examined directly, so this study tested the hypothesis that fires shortly after masting trigger increased recruitment of the obligate-seeding arid zone spinifex, Triodia pungens R. Br., an iteroparous masting grass with smoke-cued germination. Phenological monitoring of T. pungens was conducted over 5 years, while a longitudinal seedbank study assessed the influence of seeding events on soil-stored seedbank dynamics. Concurrently, a fire experiment with randomized blocking was undertaken to test whether T. pungens hummocks burnt shortly after masting have greater post-fire recruitment than hummocks burnt when there has not been recent input of seeds. Triodia pungens flowered in all years, though most flowerings were characterized by high rates of flower abortion. A mast flowering with high seed set in 2012 triggered approx. 200-fold increases in seedbank densities, and seedbank densities remained elevated for 24 months after this event. The fire experiment showed significantly higher recruitment around hummocks burnt 6 months after the 2012 mast event than around hummocks that were burnt but prevented from masting by having inflorescences clipped. Fires shortly after masting trigger mass recruitment in T. pungens because such fires synchronize an appropriate germination cue (smoke) with periods when seedbank densities are elevated. Interactions between natural fire regimes, seedbank dynamics and fire management prescriptions must be

  5. Mountain Pine Beetle Dynamics and Reproductive Success in Post-Fire Lodgepole and Ponderosa Pine Forests in Northeastern Utah

    PubMed Central

    Lerch, Andrew P.; Pfammatter, Jesse A.

    2016-01-01

    Fire injury can increase tree susceptibility to some bark beetles (Curculionidae, Scolytinae), but whether wildfires can trigger outbreaks of species such as mountain pine beetle (Dendroctonus ponderosae Hopkins) is not well understood. We monitored 1173 lodgepole (Pinus contorta var. latifolia Doug.) and 599 ponderosa (Pinus ponderosa Doug. ex Law) pines for three years post-wildfire in the Uinta Mountains of northeastern Utah in an area with locally endemic mountain pine beetle. We examined how the degree and type of fire injury influenced beetle attacks, brood production, and subsequent tree mortality, and related these to beetle population changes over time. Mountain pine beetle population levels were high the first two post-fire years in lodgepole pine, and then declined. In ponderosa pine, populations declined each year after initial post-fire sampling. Compared to trees with strip or failed attacks, mass attacks occurred on trees with greater fire injury, in both species. Overall, a higher degree of damage to crowns and boles was associated with higher attack rates in ponderosa pines, but additional injury was more likely to decrease attack rates in lodgepole pines. In lodgepole pine, attacks were initially concentrated on fire-injured trees, but during subsequent years beetles attacked substantial numbers of uninjured trees. In ponderosa pine, attacks were primarily on injured trees each year, although these stands were more heavily burned and had few uninjured trees. In total, 46% of all lodgepole and 56% of ponderosa pines underwent some degree of attack. Adult brood emergence within caged bole sections decreased with increasing bole char in lodgepole pine but increased in ponderosa pine, however these relationships did not scale to whole trees. Mountain pine beetle populations in both tree species four years post-fire were substantially lower than the year after fire, and wildfire did not result in population outbreaks. PMID:27783632

  6. Mountain Pine Beetle Dynamics and Reproductive Success in Post-Fire Lodgepole and Ponderosa Pine Forests in Northeastern Utah.

    PubMed

    Lerch, Andrew P; Pfammatter, Jesse A; Bentz, Barbara J; Raffa, Kenneth F

    2016-01-01

    Fire injury can increase tree susceptibility to some bark beetles (Curculionidae, Scolytinae), but whether wildfires can trigger outbreaks of species such as mountain pine beetle (Dendroctonus ponderosae Hopkins) is not well understood. We monitored 1173 lodgepole (Pinus contorta var. latifolia Doug.) and 599 ponderosa (Pinus ponderosa Doug. ex Law) pines for three years post-wildfire in the Uinta Mountains of northeastern Utah in an area with locally endemic mountain pine beetle. We examined how the degree and type of fire injury influenced beetle attacks, brood production, and subsequent tree mortality, and related these to beetle population changes over time. Mountain pine beetle population levels were high the first two post-fire years in lodgepole pine, and then declined. In ponderosa pine, populations declined each year after initial post-fire sampling. Compared to trees with strip or failed attacks, mass attacks occurred on trees with greater fire injury, in both species. Overall, a higher degree of damage to crowns and boles was associated with higher attack rates in ponderosa pines, but additional injury was more likely to decrease attack rates in lodgepole pines. In lodgepole pine, attacks were initially concentrated on fire-injured trees, but during subsequent years beetles attacked substantial numbers of uninjured trees. In ponderosa pine, attacks were primarily on injured trees each year, although these stands were more heavily burned and had few uninjured trees. In total, 46% of all lodgepole and 56% of ponderosa pines underwent some degree of attack. Adult brood emergence within caged bole sections decreased with increasing bole char in lodgepole pine but increased in ponderosa pine, however these relationships did not scale to whole trees. Mountain pine beetle populations in both tree species four years post-fire were substantially lower than the year after fire, and wildfire did not result in population outbreaks.

  7. Twenty Years After the 1988 Yellowstone Fires: Lessons About Disturbance and Ecosystems

    USGS Publications Warehouse

    Romme, W.H.; Boyce, M.S.; Gresswell, R.; Merrill, E.H.; Minshall, G.W.; Whitlock, C.; Turner, M.G.

    2011-01-01

    The 1988 Yellowstone fires were among the first in what has proven to be an upsurge in large severe fires in the western USA during the past 20 years. At the time of the fires, little was known about the impacts of such a large severe disturbance because scientists had had few previous opportunities to study such an event. Ecologists predicted short- and long-term effects of the 1988 fires on vegetation, biogeochemistry, primary productivity, wildlife, and aquatic ecosystems based on scientific understanding of the time. Twenty-plus years of subsequent study allow these early predictions to be evaluated. Most of the original predictions were at least partially supported, but some predictions were refuted, others nuanced, and a few postfire phenomena were entirely unexpected. Post-1988 Yellowstone studies catalyzed advances in ecology focused on the importance of spatial and temporal heterogeneity, contingent influences, and multiple interacting drivers. Post-1988 research in Yellowstone also has changed public perceptions of fire as an ecological process and attitudes towards fire management. Looking ahead to projected climate change and more frequent large fires, the well-documented ecological responses to the 1988 Yellowstone fires provide a foundation for detecting and evaluating potential changes in fire regimes of temperate mountainous regions. ?? 2011 Springer Science+Business Media, LLC.

  8. Pre- and post-fire pollutant loads in an urban fringe watershed in Southern California.

    PubMed

    Burke, M P; Hogue, T S; Kinoshita, A M; Barco, J; Wessel, C; Stein, E D

    2013-12-01

    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.

  9. Vulnerability and Resilience of Temperate Forest Landscapes to Broad-Scale Deforestation in Response to Changing Fire Regimes and Altered Post-Fire Vegetation Dynamics

    NASA Astrophysics Data System (ADS)

    Tepley, A. J.; Veblen, T. T.; Perry, G.; Anderson-Teixeira, K. J.

    2015-12-01

    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.

  10. Post-fire reconstructions of fire intensity from fire severity data: quantifying the role of spatial variability of fire intensity on forest dynamics

    NASA Astrophysics Data System (ADS)

    Baker, Patrick; Oborne, Lisa

    2015-04-01

    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

  11. Modelling post-fire vegetation recovery in Portugal

    NASA Astrophysics Data System (ADS)

    Bastos, A.; Gouveia, C. M.; Dacamara, C. C.; Trigo, R. M.

    2011-12-01

    Wildfires in Mediterranean Europe have been increasing in number and extension over the last decades and constitute one of the major disturbances of these ecosystems. Portugal is the country with more burnt area in the last decade and the years of 2003 and 2005 were particularly devastating, the total burned areas of 425 000 and 338 000 ha being several times higher than the corresponding average. The year of 2005 further coincided with one of the most severe droughts since early 20th century. Due to different responses of vegetation to diverse fire regimes and to the complexity of landscape structures, fires have complex effects on vegetation recovery. Remote sensing has revealed to be a powerful tool in studying vegetation dynamics and in monitoring post-fire vegetation recovery, which is crucial to land-management and to prevent erosion. The main goals of the present work are (i) to assess the accuracy of a vegetation recovery model previously developed by the authors; (ii) to assess the model's performance, namely its sensitivity to initial conditions, to the temporal length of the input dataset and to missing data; (iii) to study vegetation recovery over two selected areas that were affected by two large wildfire events in the fire seasons of 2003 and 2005, respectively. The study relies on monthly values of NDVI over 11 years (1998-2009), at 1 km × 1 km spatial resolution, as obtained by the VEGETATION instrument. According to results from sensitivity analysis, the model is robust and able to provide good estimations of recovery times of vegetation when the regeneration process is regular, even when missing data is present. In respect to the two selected burnt scars, results indicate that fire damage is a determinant factor of regeneration, as less damaged vegetation recovers more rapidly, which is mainly justified by the high coverage of Pinus pinaster over the area, and by the fact that coniferous forests tend to recover slower than transitional woodland

  12. Semiarid rangeland is resilient to summer fire and post-fire grazing utilization

    USDA-ARS?s Scientific Manuscript database

    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...

  13. Pre-fire fuel reduction treatments influence plant communities and exotic species 9 years after a large wildfire

    Treesearch

    Kristen L. Shive; Amanda M. Kuenzi; Carolyn H. Sieg; Peter Z. Fule

    2013-01-01

    We used a multi-year data set from the 2002 Rodeo-Chediski Fire to detect post-fire trends in plant community response in burned ponderosa pine forests. Within the burn perimeter, we examined the effects of pre-fire fuels treatments on post-fire vegetation by comparing paired treated and untreated sites on the Apache-Sitgreaves National Forest.We sampled these paired...

  14. Rapid response tools and datasets for post-fire modeling: Linking Earth Observations and process-based hydrological models to support post-fire remediation

    Treesearch

    M. E. Miller; M. Billmire; W. J. Elliot; K. A. Endsley; P. R. Robichaud

    2015-01-01

    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...

  15. First report of the post-fire morel Morchella exuberans in eastern North America.

    PubMed

    Miller, Andrew N; Raudabaugh, Daniel B; Iturriaga, Teresa; Matheny, P Brandon; Petersen, Ronald H; Hughes, Karen W; Gube, Matthias; Powers, Rob A; James, Timothy Y; O'Donnell, Kerry

    2017-01-01

    Reports of true morels (Morchella) fruiting on conifer burn sites are common in western North America where five different fire-adapted species of black morels (Elata Clade) have been documented based on multilocus phylogenetic analyses. Fruiting of post-fire morels in eastern North America, by comparison, are rare and limited to a report from Minnesota in 1977 and eastern Ontario in 1991. Here, nuc rDNA internal transcribed spacer (ITS1-5.8S-ITS2 = ITS) sequences were used to identify the post-fire morel that fruited in great abundance the year following the 2012 Duck Lake Fire in the Upper Peninsula of Michigan and after the 2016 large-scale fire in the Great Smoky Mountains National Park in Tennessee as M. exuberans. A preliminary phylogenetic analysis suggests that the collections from eastern North America may be more closely related to those from Europe than from western North America, Europe, and China.

  16. Post-fire drought effects and their legacy on soil functionality and microbial community structure in a Mediterranean shrubland

    NASA Astrophysics Data System (ADS)

    Belen Hinojosa, M.; Parra, Antonio; Laudicina, V. Armando; Moreno, José M.

    2017-04-01

    Climate change in subtropical areas, like the Mediterranean, is projected to decrease precipitation and to lengthen the seasonal drought period. Fire danger is also projected to increase under the most severe conditions. Little is known about the effects of increasing drought and, particularly, its legacy when precipitation resumes to normal, on the recovery of burned ecosystems. Here we studied the effects of post-fire drought and its legacy two years after it stopped on soil microbial community structure and functionality of a Cistus-Erica shrubland. To do this, a manipulative experiment was setup in which rainfall total patterns were modified by means of a rain-out shelters and irrigation system in a fully replicated set of previously burned plots. The treatments were: environmental control (natural rainfall), historical control (average rainfall, 2 months drought), moderate drought (25% reduction of historical control, 5 months drought) and severe drought (45% reduction, 7 months drought). One set of unburned plots under natural rainfall served as an additional control. Availability of the main soil nutrients and microbial community composition and functionality were monitored over 4 years under these rainfall manipulation treatments. Thereafter, treatments were discontinued and plots were subjected to ambient rainfall for two additional years. Post-fire drought had not effect on total C or N. Fire increased soil P and N availability. However, post-fire drought reduced available soil P and increased nitrate in the short term. Post- fire reduction of available K was accentuated by continued drought. Fire significantly reduced soil organic matter, enzyme activities and carbon mineralization, mainly in drought treated soils. Fire also decreased soil microbial biomass and the proportion of fungi, while that of actinomycetes increased in the short term. Post-fire drought accentuated the decrease of soil total microbial biomass and fungi, with bacteria becoming more

  17. Towards improved quantification of post-fire conifer mortality and recovery: Impacts of fire radiative flux on seedling and mature tree mortality, physiology, and growth

    NASA Astrophysics Data System (ADS)

    Sparks, A. M.; Kolden, C.; Smith, A. M.

    2016-12-01

    Fire activity, in terms of intensity, frequency, and total area burned, is expected to increase with changing climate. A challenge for landscape level assessment of fire effects, termed burn severity, is that current assessments provide very little information regarding vegetation physiological performance and recovery, limiting our understanding of fire effects on ecosystem services such as carbon storage/cycling. To address these limitations, we evaluated an alternative dose-response methodology for quantifying fire effects that attempts to bridge fire combustion dynamics and ecophysiology. Specifically, we conducted a highly controlled, laboratory assessment of seedling response to increasing doses of fire radiative energy applied through surface fires, for two western U.S. conifer species. Seedling physiology and spectral reflectance were acquired pre- and up to 1 year post-fire. Post-fire mortality, physiological performance, and spectral reflectance were strongly related with fire radiative energy density (FRED: J m-2) dose. To examine how these relationships change with tree size and age, we conducted small prescribed fires at the tree scale (35 m2) in a mature conifer stand. Radial growth and resin duct defenses were assessed on the mature conifer trees following the prescribed fires. Differences in dose-response relationships between seedlings and mature trees indicate the importance of fire behavior (e.g., flaming-dominated versus smoldering-dominated combustion) in characterizing these relationships. Ultimately, these results suggest that post-fire impacts on growth of surviving seedlings and mature trees require modes of heat transfer to impact tree canopies.

  18. Studying the Post-Fire Response of Vegetation in California Protected Areas with NDVI-based Pheno-Metrics

    NASA Astrophysics Data System (ADS)

    Jia, S.; Gillespie, T. W.

    2016-12-01

    Post-fire response from vegetation is determined by the intensity and timing of fires as well as the nature of local biomes. Though the field-based studies focusing on selected study sites helped to understand the mechanisms of post-fire response, there is a need to extend the analysis to a broader spatial extent with the assistance of remotely sensed imagery of fires and vegetation. Pheno-metrics, a series of variables on the growing cycle extracted from basic satellite measurements of vegetation coverage, translate the basic remote sensing measurements such as NDVI to the language of phenology and fire ecology in a quantitative form. In this study, we analyzed the rate of biomass removal after ignition and the speed of post-fire recovery in California protected areas from 2000 to 2014 with USGS MTBS fire data and USGS eMODIS pheno-metrics. NDVI drop caused by fire showed the aboveground biomass of evergreen forest was removed much slower than shrubland because of higher moisture level and greater density of fuel. In addition, the above two major land cover types experienced a greatly weakened immediate post-fire growing season, featuring a later start and peak of season, a shorter length of season, and a lower start and peak of NDVI. Such weakening was highly correlated with burn severity, and also influenced by the season of fire and the land cover type, according to our modeling between the anomalies of pheno-metrics and the difference of normalized burn ratio (dNBR). The influence generally decayed over time, but can remain high within the first 5 years after fire, mostly because of the introduction of exotic species when the native species were missing. Local-specific variables are necessary to better address the variance within the same fire and improve the outcomes of models. This study can help ecologists in validating the theories of post-fire vegetation response mechanisms and assist local fire managers in post-fire vegetation recovery.

  19. Characterization and evaluation of controls on post-fire streamflow response across western US watersheds

    NASA Astrophysics Data System (ADS)

    Saxe, Samuel; Hogue, Terri S.; Hay, Lauren

    2018-02-01

    This research investigates the impact of wildfires on watershed flow regimes, specifically focusing on evaluation of fire events within specified hydroclimatic regions in the western United States, and evaluating the impact of climate and geophysical variables on response. Eighty-two watersheds were identified with at least 10 years of continuous pre-fire daily streamflow records and 5 years of continuous post-fire daily flow records. Percent change in annual runoff ratio, low flows, high flows, peak flows, number of zero flow days, baseflow index, and Richards-Baker flashiness index were calculated for each watershed using pre- and post-fire periods. Independent variables were identified for each watershed and fire event, including topographic, vegetation, climate, burn severity, percent area burned, and soils data. Results show that low flows, high flows, and peak flows increase in the first 2 years following a wildfire and decrease over time. Relative response was used to scale response variables with the respective percent area of watershed burned in order to compare regional differences in watershed response. To account for variability in precipitation events, runoff ratio was used to compare runoff directly to PRISM precipitation estimates. To account for regional differences in climate patterns, watersheds were divided into nine regions, or clusters, through k-means clustering using climate data, and regression models were produced for watersheds grouped by total area burned. Watersheds in Cluster 9 (eastern California, western Nevada, Oregon) demonstrate a small negative response to observed flow regimes after fire. Cluster 8 watersheds (coastal California) display the greatest flow responses, typically within the first year following wildfire. Most other watersheds show a positive mean relative response. In addition, simple regression models show low correlation between percent watershed burned and streamflow response, implying that other watershed factors

  20. Determinants of Post-fire Water Quality in the Western United States

    NASA Astrophysics Data System (ADS)

    Rust, A.; Saxe, S.; Dolan, F.; Hogue, T. S.; McCray, J. E.

    2015-12-01

    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

  1. Detecting post-fire salvage logging with Landsat change maps and national fire survey data

    Treesearch

    Todd A. Schroeder; Michael A. Wulder; Sean P. Healey; Gretchen G. Moisen

    2012-01-01

    In Canadian boreal forests, wildfire is the predominant agent of natural disturbance often with millions of hectares burning annually. In addition to fire, nearly one quarter of Canada's boreal forest is also managed for industrial wood production. Post-fire logging (or salvage harvesting) is increasingly used to minimize economic losses from fire, notwithstanding...

  2. Monitoring post-fire vegetation regeneration in a Madrean ecosystem

    Treesearch

    Kelley J. O' Neal; John Rogan; Stephen R. Yool

    2005-01-01

    Fire suppression over the past century has contributed to the conversion of grasslands to shrublands in Sky Island communities. Two prescribed fires were ignited in the Peloncillo Mountains: Baker Canyon in 1995 and Maverick Spring in 1997. Remote sensing data were used to examine prescribed fire effectiveness in reducing shrub cover and to monitor post-fire...

  3. Avian community responses to post-fire forest structure: implications for fire management in mixed conifer forests

    Treesearch

    Angela White; Patricia Manley; Gina Tarbill; T. W. Richardson; R. E. Russell; H. D. Safford; S. Z. Dobrowski

    2016-01-01

    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...

  4. Linear Modeling and Evaluation of Controls on Flow Response in Western Post-Fire Watersheds

    NASA Astrophysics Data System (ADS)

    Saxe, S.; Hogue, T. S.; Hay, L.

    2015-12-01

    This research investigates the impact of wildfires on watershed flow regimes throughout the western United States, specifically focusing on evaluation of fire events within specified subregions and determination of the impact of climate and geophysical variables in post-fire flow response. Fire events were collected through federal and state-level databases and streamflow data were collected from U.S. Geological Survey stream gages. 263 watersheds were identified with at least 10 years of continuous pre-fire daily streamflow records and 5 years of continuous post-fire daily flow records. For each watershed, percent changes in runoff ratio (RO), annual seven day low-flows (7Q2) and annual seven day high-flows (7Q10) were calculated from pre- to post-fire. Numerous independent variables were identified for each watershed and fire event, including topographic, land cover, climate, burn severity, and soils data. The national watersheds were divided into five regions through K-clustering and a lasso linear regression model, applying the Leave-One-Out calibration method, was calculated for each region. Nash-Sutcliffe Efficiency (NSE) was used to determine the accuracy of the resulting models. The regions encompassing the United States along and west of the Rocky Mountains, excluding the coastal watersheds, produced the most accurate linear models. The Pacific coast region models produced poor and inconsistent results, indicating that the regions need to be further subdivided. Presently, RO and HF response variables appear to be more easily modeled than LF. Results of linear regression modeling showed varying importance of watershed and fire event variables, with conflicting correlation between land cover types and soil types by region. The addition of further independent variables and constriction of current variables based on correlation indicators is ongoing and should allow for more accurate linear regression modeling.

  5. Index for characterizing post-fire soil environments in temperate coniferous forests

    Treesearch

    Theresa B. Jain; David S. Pilliod; Russell T. Graham; Leigh B. Lentile; Jonathan E. Sandquist

    2012-01-01

    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...

  6. Small mammal abundance in Mediterranean post-fire habitats: a role for predators?

    NASA Astrophysics Data System (ADS)

    Torre, I.; Díaz, M.

    2004-05-01

    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.

  7. An evaluation of three wood shred blends for post-fire erosion control using indoor simulated rain events on small plots

    Treesearch

    R. B. Foltz; N. S. Wagenbrenner

    2010-01-01

    The assessment teams who make post-fire stabilization and treatment decisions are under pressure to employ more effective and economic post-fire treatments, as wild fire activity and severity has increased in recent years across the western United States. Use of forest-native wood-based materials for hillslope mulching has been on the rise due to potential...

  8. Monitoring Changes in Soil Quality from Post-fire Logging in the Inland Northwest

    Treesearch

    Deborah Page-Dumroese; Martin Jurgensen; Ann Abbott; Tom Rice; Joanne Tirocke; Sue Farley; Sharon DeHart

    2006-01-01

    The wildland fires of 2000, 2002, and 2003 created many opportunities to conduct post-fire logging operations in the Inland Northwest. Relatively little information is available on the impact of post-fire logging on long-term soil productivity or on the best method for monitoring these changes. We present a USDA Forest Service Northern Region study of post-fire logged...

  9. A new parameterization of the post-fire snow albedo effect

    NASA Astrophysics Data System (ADS)

    Gleason, K. E.; Nolin, A. W.

    2013-12-01

    Mountain snowpack serves as an important natural reservoir of water: recharging aquifers, sustaining streams, and providing important ecosystem services. Reduced snowpacks and earlier snowmelt have been shown to affect fire size, frequency, and severity in the western United States. In turn, wildfire disturbance affects patterns of snow accumulation and ablation by reducing canopy interception, increasing turbulent fluxes, and modifying the surface radiation balance. Recent work shows that after a high severity forest fire, approximately 60% more solar radiation reaches the snow surface due to the reduction in canopy density. Also, significant amounts of pyrogenic carbon particles and larger burned woody debris (BWD) are shed from standing charred trees, which concentrate on the snowpack, darken its surface, and reduce snow albedo by 50% during ablation. Although the post-fire forest environment drives a substantial increase in net shortwave radiation at the snowpack surface, driving earlier and more rapid melt, hydrologic models do not explicitly incorporate forest fire disturbance effects to snowpack dynamics. The objective of this study was to parameterize the post-fire snow albedo effect due to BWD deposition on snow to better represent forest fire disturbance in modeling of snow-dominated hydrologic regimes. Based on empirical results from winter experiments, in-situ snow monitoring, and remote sensing data from a recent forest fire in the Oregon High Cascades, we characterized the post-fire snow albedo effect, and developed a simple parameterization of snowpack albedo decay in the post-fire forest environment. We modified the recession coefficient in the algorithm: α = α0 + K exp (-nr) where α = snowpack albedo, α0 = minimum snowpack albedo (≈0.4), K = constant (≈ 0.44), -n = number of days since last major snowfall, r = recession coefficient [Rohrer and Braun, 1994]. Our parameterization quantified BWD deposition and snow albedo decay rates and

  10. Modelling post-fire vegetation recovery in Portugal

    NASA Astrophysics Data System (ADS)

    Bastos, A.; Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

    2011-05-01

    Wildfires in Mediterranean Europe have been increasing in number and extension over the last decades and constitute one of the major disturbances of these ecosystems. Portugal is the country with more burnt area in the last decade and the years of 2003 and 2005 were particularly devastating, the total burned areas of 425 000 and 338 000 ha being several times higher than the corresponding average. The year of 2005 further coincided with one of the most severe droughts since early 20th century. Due to different responses of vegetation to diverse fire regimes and to the complexity of landscape structures, fires have complex effects on vegetation recovery. Remote sensing has revealed to be a powerful tool in studying vegetation dynamics and in monitoring post-fire vegetation recovery, which is crucial to land-management and to prevent erosion. The main goals of the present work are (i) to assess the accuracy of a vegetation recovery model previously developed by the authors; (ii) to assess the model's performance, namely its sensitivity to initial conditions, to the temporal length of the input dataset and to missing data; (iii) to study vegetation recovery over two selected areas that were affected by two large wildfire events in the fire seasons of 2003 and 2005, respectively. The study relies on monthly values of NDVI over 11 yr (1998-2009), at 1 × 1 km spatial resolution, as obtained by the VEGETATION instrument. According to results from sensitivity analysis, the model is robust and able to provide good estimations of recovery times of vegetation when the regeneration process is regular, even when missing data is present. In what respect to the two selected burnt scars, results indicate that fire damage is a determinant factor of regeneration, as less damaged vegetation recovers more rapidly, which is mainly justified by the high coverage of Pinus Pinaster over the area, and by the fact that coniferous forests tend to recover slower than transitional woodland

  11. Modelling threats to water quality from fire suppression chemicals and post-fire erosion

    NASA Astrophysics Data System (ADS)

    Hyde, Kevin; Ziemniak, Chris; Elliot, William; Samuels, William

    2014-05-01

    Misapplication of fire retardant chemicals into streams and rivers may threaten aquatic life. The possible threat depends on the contaminant concentration that, in part, is controlled by dispersion within flowing water. In the event of a misapplication, methods are needed to rapidly estimate the chemical mass entering the waterway and the dispersion and transport within the system. Here we demonstrate a new tool that calculates the chemical mass based on aircraft delivery system, fire chemical type, and stream and intersect geometry. The estimated mass is intended to be transferred into a GIS module that uses real-time stream data to map and simulate the dispersion and transport downstream. This system currently accounts only for aqueous transport. We envision that the GIS module can be modified to incorporate sediment transport, specifically to model movement of sediments from post-fire erosion. This modification could support assessment of threats of post-fire erosion to water quality and water supply systems.

  12. Fire intensity drives post-fire temporal pattern of soil carbon accumulation in Australian fire-prone forests.

    PubMed

    Sawyer, Robert; Bradstock, Ross; Bedward, Michael; Morrison, R John

    2018-01-01

    The impact of fire on global C cycles is considerable but complex. Nevertheless, studies on patterns of soil C accumulation following fires of differing intensity over time are lacking. Our study utilised 15 locations last burnt by prescribed fire (inferred low intensity) and 18 locations last burnt by wildfire (inferred high intensity), with time since fire (TSF) up to 43years, in a homogenous forest type in south eastern Australia. Following a stratified approach to mineral soil sampling, the soil % total C (% C Tot ) and % recalcitrant pyrogenic C (% RPC), were estimated. Generalised additive models indicated increases in % C Tot at TSF >30years in sites last burnt by wildfire. Estimates in sites last subjected to prescribed fire however, remained constant across the TSF chronosequence. There was no significant difference in % C Tot between the different fire types for the first 20years after fire. In the first 10years after wildfires, % RPC was elevated, declining to a minimum at ca. TSF 25years. After prescribed fires, % RPC was unaffected by TSF. Differences in response of % C Tot and % RPC to fire type may reflect the strength of stimulation of early successional processes and extent of charring. The divergent response to fire type in % C Tot was apparent at TSF longer than the landscape average fire return interval (i.e., 15 to 20years). Thus, any attempt to increase C sequestration in soils would require long-term exclusion of fire. Conversely, increased fire frequency is likely to have negligible impact on soil C stocks in these forests. Further investigation of the effects of fire frequency, fire intensity combinations and interaction of fire with other disturbances will enhance prediction of the likely impact of imposed or climatically induced changes to fire regimes on soil C. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Post-fire bedload sediment delivery across spatial scales in the interior western United States

    Treesearch

    Joseph W. Wagenbrenner; Peter R. Robichaud

    2014-01-01

    Post-fire sediment yields can be up to three orders of magnitude greater than sediment yields in unburned forests. Much of the research on post-fire erosion rates has been at small scales (100m2 or less), and post-fire sediment delivery rates across spatial scales have not been quantified in detail. We developed relationships for post-fire bedload sediment delivery...

  14. Significant or negligible sediment and nutrient losses after fire? Pre- and post-fire comparisons

    NASA Astrophysics Data System (ADS)

    Shakesby, R. A.; Ferreira, A. J. D.; Ferreira, C. S. S.; Stoof, C. R.; Urbanek, E.; Walsh, R. P. D.

    2009-04-01

    Prescribed fire (or a controlled burn) is a management tool used in wildfire-prone areas to reduce the fuel load of living and dead biomass, while attempting to keep disturbance of the ground surface and soil to a minimum. We know that wildfire, particularly of moderate or extreme severity, can cause important changes to the chemical and physical properties of soil, typically leading to a reduction in aggregate stability, surface roughness and water storage capacity, and an increase in overland flow. It has also been shown that wildfire disturbance can cause major loss of soil, particularly at plot and hillslope scales. There is less information on soil losses at catchment scales, but it is known that losses particularly of organic-rich fine sediment and nutrients can undergo hillslope to channel transfer, where they can affect water quality. Far less research has been carried out into the effects of prescribed fire on soil and nutrient losses at all scales, but particularly at catchment scales. This paper considers the impact of an experimental fire (equivalent to a severe prescribed fire) on soil and nutrient losses. These losses have been monitored at a range of scales (small rainfall simulation plots, long-term erosion plot, erosion plot, hillslope sediment traps (sediment fences) and catchment) before and after the fire in a 10-ha catchment near Góis, central Portugal, which forms part of the 5-year DESIRE research programme concerning desertification and its mitigation at a range of study sites worldwide. The catchment has steep slopes covered mainly with scrub vegetation ranging from c. 0.15 to 2m in height. The soil is thin, stony and highly water repellent. Long-term pre-burn erosion rates are known from a c. 10-year record of soil losses from a small erosion plot (8 x 2m in size) and sediment accumulation in the weir pool of a subcatchment gauging station. Rainfall simulations carried out under dry and wet antecedent conditions before and after the fire

  15. A synthesis of post-fire Burned Area Reports from 1972 to 2009 for western US Forest Service lands: Trends in wildfire characteristics and post-fire stabilisation treatments and expenditures

    Treesearch

    Peter R. Robichaud; Hakjun Rhee; Sarah A. Lewis

    2014-01-01

    Over 1200 post-fire assessment and treatment implementation reports from four decades (1970s-2000s) of western US forest fires have been examined to identify decadal patterns in fire characteristics and the justifications and expenditures for the post-fire treatments. The main trends found were: (1) the area burned by wildfire increased over time and the rate of...

  16. Taxonomic and Functional Responses to Fire and Post-Fire Management of a Mediterranean Hymenoptera Community

    NASA Astrophysics Data System (ADS)

    Mateos, Eduardo; Santos, Xavier; Pujade-Villar, Juli

    2011-11-01

    Fire is one of the commonest disturbances worldwide, transforming habitat structure and affecting ecosystem functioning. Understanding how species respond to such environmental disturbances is a major conservation goal that should be monitored using functionally and taxonomically diverse groups such as Hymenoptera. In this respect, we have analyzed the taxonomic and functional response to fire and post-fire management of a Hymenoptera community from a Mediterranean protected area. Thus, Hymenoptera were sampled at fifteen sites located in three burnt areas submitted to different post-fire practices, as well as at five sites located in peripheral unburnt pine forest. A total of 4882 specimens belonging to 33 families, which were classified into six feeding groups according to their dietary preferences, were collected. ANOVA and Redundancy Analyses showed a taxonomic and functional response to fire as all burnt areas had more Hymenoptera families, different community composition and higher numbers of parasitoids than the unburnt area. Taxonomic differences were also found between burnt areas in terms of the response of Hymenoptera to post-fire management. In general the number of parasitoids was positively correlated to the number of potential host arthropods. Parasitoids are recognized to be sensitive to habitat changes, thus highlighting their value for monitoring the functional responses of organisms to habitat disturbance. The taxonomic and functional responses of Hymenoptera suggest that some pine-forest fires can enhance habitat heterogeneity and arthropod diversity, hence increasing interspecific interactions such as those established by parasitoids and their hosts.

  17. Taxonomic and functional responses to fire and post-fire management of a Mediterranean hymenoptera community.

    PubMed

    Mateos, Eduardo; Santos, Xavier; Pujade-Villar, Juli

    2011-11-01

    Fire is one of the commonest disturbances worldwide, transforming habitat structure and affecting ecosystem functioning. Understanding how species respond to such environmental disturbances is a major conservation goal that should be monitored using functionally and taxonomically diverse groups such as Hymenoptera. In this respect, we have analyzed the taxonomic and functional response to fire and post-fire management of a Hymenoptera community from a Mediterranean protected area. Thus, Hymenoptera were sampled at fifteen sites located in three burnt areas submitted to different post-fire practices, as well as at five sites located in peripheral unburnt pine forest. A total of 4882 specimens belonging to 33 families, which were classified into six feeding groups according to their dietary preferences, were collected. ANOVA and Redundancy Analyses showed a taxonomic and functional response to fire as all burnt areas had more Hymenoptera families, different community composition and higher numbers of parasitoids than the unburnt area. Taxonomic differences were also found between burnt areas in terms of the response of Hymenoptera to post-fire management. In general the number of parasitoids was positively correlated to the number of potential host arthropods. Parasitoids are recognized to be sensitive to habitat changes, thus highlighting their value for monitoring the functional responses of organisms to habitat disturbance. The taxonomic and functional responses of Hymenoptera suggest that some pine-forest fires can enhance habitat heterogeneity and arthropod diversity, hence increasing interspecific interactions such as those established by parasitoids and their hosts.

  18. Post-Fire Spatial Patterns of Soil Nitrogen Mineralization and Microbial Abundance

    PubMed Central

    Smithwick, Erica A. H.; Naithani, Kusum J.; Balser, Teri C.; Romme, William H.; Turner, Monica G.

    2012-01-01

    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

  19. Post-fire vegetation and fuel development influences fire severity patterns in reburns.

    PubMed

    Coppoletta, Michelle; Merriam, Kyle E; Collins, Brandon M

    2016-04-01

    In areas where fire regimes and forest structure have been dramatically altered, there is increasing concern that contemporary fires have the potential to set forests on a positive feedback trajectory with successive reburns, one in which extensive stand-replacing fire could promote more stand-replacing fire. Our study utilized an extensive set of field plots established following four fires that occurred between 2000 and 2010 in the northern Sierra Nevada, California, USA that were subsequently reburned in 2012. The information obtained from these field plots allowed for a unique set of analyses investigating the effect of vegetation, fuels, topography, fire weather, and forest management on reburn severity. We also examined the influence of initial fire severity and time since initial fire on influential predictors of reburn severity. Our results suggest that high- to moderate-severity fire in the initial fires led to an increase in standing snags and shrub vegetation, which in combination with severe fire weather promoted high-severity fire effects in the subsequent reburn. Although fire behavior is largely driven by weather, our study demonstrates that post-fire vegetation composition and structure are also important drivers of reburn severity. In the face of changing climatic regimes and increases in extreme fire weather, these results may provide managers with options to create more fire-resilient ecosystems. In areas where frequent high-severity fire is undesirable, management activities such as thinning, prescribed fire, or managed wildland fire can be used to moderate fire behavior not only prior to initial fires, but also before subsequent reburns.

  20. Post-fire environments are favourable for plant functioning of seeder and resprouter Mediterranean shrubs, even under drought.

    PubMed

    Parra, Antonio; Moreno, José M

    2017-05-01

    Understanding how drought affects seeder and resprouter plants during post-fire regeneration is important for the anticipation of Mediterranean vegetation vulnerability in a context of increasing drought and fire caused by climate change. A Mediterranean shrubland was subjected to various drought treatments (including 45% rainfall reduction, 7 months drought yr -1 ), before and after experimental burning, by means of a rainout-shelter system with an irrigation facility. Predawn shoot water potential (Ψ pd ), relative growth rate (RGR), specific leaf area (SLA) and bulk leaf carbon isotopic composition (δ 13 C) were monitored in the main woody species during the first 3 yr after fire. Cistus ladanifer seedlings showed higher Ψ pd , RGR and SLA, and lower δ 13 C, than unburned plants during the first two post-fire years. Seedlings under drought maintained relatively high Ψ pd , but suffered a decrease in Ψ pd and RGR, and an increase in δ 13 C, relative to control treatments. Erica arborea, E. scoparia and Phillyrea angustifolia resprouts had higher Ψ pd and RGR than unburned plants during the first post-fire year. Resprouters were largely unaffected by drought. Overall, despite marked differences between the two functional groups, post-fire environments were favourable for plant functioning of both seeder and resprouter shrubs, even under the most severe drought conditions implemented. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  1. Forest Fires and Post - Fire Regeneration in Algeria Analysis with Satellite Data

    NASA Astrophysics Data System (ADS)

    Zegrar, Ahmed

    2016-07-01

    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.

  2. On the use of satellite VEGETATION time series for monitoring post fire vegetation recovery

    NASA Astrophysics Data System (ADS)

    de Santis, F.; Didonna, I.

    2009-04-01

    decade of January, by averaging over all years in the record. We analyzed both: 1) Time variation of NDVI from 1998 to 2005 of pixels for the fire affected and fire unaffected areas. 2) Post-fire NDVI spatial patterns on each image date were compared to the pre-fire pattern to determine the extent to which the pre-fire pattern was re-established, and the rate of this recovery. Results show the ability of vegetation to recovery after a single fire. Nevertheless, such ability can be strongly reduced by successive fires. The recursive fire occurrence can significantly diminish the green biomass especially when disturbances occur at short intervals of time.

  3. Vegetation response after post-fire mulching and native grass seeding

    Treesearch

    Penelope Morgan; Marshell Moy; Christine A. Droske; Leigh B. Lentile; Sarah A. Lewis; Peter R. Robichaud; Andrew T. Hudak

    2014-01-01

    Post-fire mulch and seeding treatments, often applied on steep, severely burned slopes immediately after large wildfires, are meant to reduce the potential of erosion and establishment of invasive plants, especially non-native plants, that could threaten values at risk. However, the effects of these treatments on native vegetation response post fire are little studied...

  4. Size-dependent enhancement of water relations during post-fire resprouting.

    PubMed

    Schafer, Jennifer L; Breslow, Bradley P; Hollingsworth, Stephanie N; Hohmann, Matthew G; Hoffmann, William A

    2014-04-01

    In resprouting species, fire-induced topkill causes a reduction in height and leaf area without a comparable reduction in the size of the root system, which should lead to an increase in the efficiency of water transport after fire. However, large plants undergo a greater relative reduction in size, compared with small plants, so we hypothesized that this enhancement in hydraulic efficiency would be greatest among large growth forms. In the ecotone between long-leaf pine (Pinus palustris Mill.) savannas and wetlands, we measured stomatal conductance (gs), mid-day leaf water potential (Ψleaf), leaf-specific whole-plant hydraulic conductance (KL.p), leaf area and height of 10 species covering a range of growth forms in burned and unburned sites. As predicted, KL.p was higher in post-fire resprouts than in unburned plants, and the post-fire increase in KL.p was positively related to plant size. Specifically, large-statured species tended to undergo the greatest relative reductions in leaf area and height, and correspondingly experienced the greatest increases in KL.p. The post-fire increase in KL.p was smaller than expected, however, due to a decrease in absolute root hydraulic conductance (i.e., not scaled to leaf area). The higher KL.p in burned sites was manifested as an increase in gs rather than an increase in Ψleaf. Post-fire increases in gs should promote high rates of photosynthesis for recovery of carbohydrate reserves and aboveground biomass, which is particularly important for large-statured species that require more time to recover their pre-fire size.

  5. Environmental and climatic variables as potential drivers of post-fire cover of cheatgrass (Bromus tectorum) in seeded and unseeded semiarid ecosystems

    USGS Publications Warehouse

    Shinneman, D.J.; Baker, W.L.

    2009-01-01

    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.

  6. Effects of fire and subsequent channel-reorganizing events on invertebrate drift and rainbow trout diet in small headwater streams 10 years post-disturbance

    NASA Astrophysics Data System (ADS)

    Rosenberger, A. E.; Dunham, J. B.; Wipfli, M. S.; Buffington, J. M.

    2005-05-01

    Studies examining the effects of fire on the biota of streams are often confined to immediate post-disturbance impacts; however it is also important to consider longer-term effects of fire and fire-related channel disturbances, including both negative and positive influences on stream communities. Fire and subsequent debris flows and hyperconcentrated flows destroy streamside vegetation and alter the channel morphology such that streams are wider and shallower with larger, less mobile substrate. Increased light, high temperatures, and altered stream morphology have the potential to greatly impact invertebrate communities, invertebrate drift, and drift-feeding fish diet. The goal of our study was to determine the effects of wildfire and wildfire-related disturbance on the amount and composition of stream invertebrate drift and how that translates to the diet of resident fishes 10 years post-disturbance. In the summer and fall of 2003, we set drift nets and examined the diet of fishes in 9 streams: 3 unburned; 3 burned (1992-4); and 3 burned with a subsequent channel disturbance (1992-4). Key questions include: does the taxonomic composition (richness, functional feeding groups), origin (terrestrial or aquatic), or total production (biomass) of invertebrate drift and fish diet vary with burn history? Does the composition and biomass of invertebrate drift indicate main sources of energy (allochthonous vs. autochthonous) for headwater streams affected by fire? Differences among streams in channel morphology, streamside vegetation, light input, and temperature did not correspond to consistent or marked differences in invertebrate drift productivity and only slight differences in functional feeding group composition. However, preliminary data suggest that taxon richness, though similar among burned and unburned streams, is lowest in burned and disturbed streams. Although there is a terrestrial component to fish diet in all three treatment groups, in the summer, there is

  7. Condition of live fire-scarred ponderosa pine eleven years after removing partial cross-sections

    Treesearch

    Emily K. Heyerdahl; Steven J. McKay

    2008-01-01

    Our objective is to report mortality rates for ponderosa pine trees in Oregon ten to eleven years after removing a fire-scarred partial cross-section from them, and five years after an initial survey of post-sampling mortality. We surveyed 138 live trees from which we removed fire-scarred partial crosssections in 1994/95 and 387 similarly sized, unsampled neighbor...

  8. A New Application to Facilitate Post-Fire Recovery and Rehabilitation in Savanna Ecosystems

    NASA Technical Reports Server (NTRS)

    Carroll, Mark L.; Schnase, John L.; Weber, Keith T.; Brown, Molly E.; Gill, Roger L.; Haskett, George W.; Gardner, Tess A.

    2013-01-01

    The U.S. government spends an estimated $3billion per year to fight forest fires in the United States. Post-fire rehabilitation activities represent a small but essential portion of that total. The Rehabilitation Capability Convergence for Ecosystem Recovery (RECOVER) system is currently under development for Savanna ecosystems in the western U.S. The prototype of this system has been built and will have realworld testing during the summer 2013 fire season. When fully deployed, the RECOVER system will provide the emergency rehabilitation teams with critical and timely information for management decisions regarding stabilization and rehabilitation strategies.

  9. A rapid response database in support of post-fire hydrological modeling

    Treesearch

    Mary Ellen Miller; William J. Elliot

    2016-01-01

    Being prepared for an emergency is important. Every year wildfires threaten homes and lives, but danger persists even after the flames are extinguished. Post-fire flooding and erosion (Figure 1) can threaten lives, property, and natural resources. To respond to this threat, interdisciplinary Burned Area Emergency Response (BAER) teams assess potential erosion and flood...

  10. Fire impact and assessment of post-fire actions of a typical Mediterranean forest from SW Spain

    NASA Astrophysics Data System (ADS)

    Jiménez-González, Marco A.; María De la Rosa, José; Jiménez-Morillo, Nicasio T.; Zavala, Lorena M.; Knicker, Heike

    2015-04-01

    Wildfires may cause significant changes in soil physical and chemical properties. In addition, soil organic matter (SOM) content and chemical properties are usually affected by fire. Fire impacts may negatively affect soil health and quality, and induce or enhance runoff generation and, thereby, soil erosion risk and cause damages to the habitat of species. This fact is especially dramatic in Mediterranean ecosystems, where forest fires are a frequent phenomenon and restoration strategies are a key issue. The goals of this study are to determine: i) the immediate effects of fire on soil properties, including changes occurred in the quantity and quality of SOM and ii) the effect of post-fire actions on soil properties. In August 2012, a wildfire affected a forest area of approx. 90 ha in Montellano (Seville, SW Spain; longitude 37.00 °, latitude -5.56 °). This area is dominated by pines (Pinus pinaster and Pinus halepensis), and eucalypts (Eucaliptus globulus) with a Mediterranean climate. Dominant soil types are Rendzic Leptosols and Calcaric Haplic Regosols. It is a poorly limestone-developed soil (usually swallower than 25 cm). Four soil subsamples were collected 1 month and 25 months after fire within an area of approximately 200 m2. Subsamples were mixed together, homogenized, air-dried, crushed and sieved (2 mm). One control sample was collected in an adjacent area. The litter layer was removed by hand and studied separately. Branches, stems, bushes and plant residues on the fire-affected area were removed 16 months after the fire using heavy machinery as part of the post-fire management. The present research focuses on the study of the elemental composition (C, H and N) and physical properties (pH, water holding capacity, electrical conductivity) of bulk soil samples, and on the spectroscopic analysis (FT-IR, 13C NMR) and analytical pyrolysis data obtained from bulk the oils and from the humic acid fraction. immediate effects of fire, including the charring

  11. The influence of fire history, plant species and post-fire management on soil water repellency in a Mediterranean catchment: the Mount Carmel range, Israel

    NASA Astrophysics Data System (ADS)

    Keesstra, Saskia; Wittenberg, Lea; Maroulis, Jerry; Malkinson, Dan; Cerdà, Artemi; Pereira, Paulo

    2016-04-01

    Fire is a key factor impacting soil hydrology in many Mediterranean catchments. Soil water repellency (SWR) can stimulate land degradation processes by reducing the affinity of soil and water thereby triggering a reduction in soil fertility and increasing soil and water losses (. The effects of two consequent fires (1989 and 2005) on SWR were assessed in the Carmel Mountains, Israel. Fire history, plant recovery and post-fire management were investigated as determining factors in a time dependent system. SWR was highest in the >50 years unburnt plots, where soil under Pinus halepensis is most hydrophobic. In the most disturbed soils (twice burnt), many sites have a low to absent SWR even if the soil is very dry. The dynamics and fluctuations in SWR differ in magnitude under different plant species. The areas treated with CC (chipping of charred trees) showed a much higher SWR than areas left untreated. From these insights, a conceptual model of the reaction of SWR on multiple fires was developed. KEYWORDS: Soil water repellency, WDPT, Wildfires, Vegetation recovery, post-fire management, Mediterranean.

  12. Drought impact on vegetation in pre and post fire events in Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Gouveia, C. M.; Bastos, A.; Trigo, R. M.; DaCamara, C.

    2012-04-01

    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

  13. Post-fire ecosystem recovery trajectories along burn severity gradients

    NASA Astrophysics Data System (ADS)

    Newingham, B. A.; Hudak, A. T.; Bright, B. C.; Smith, A. G.; Henareh Khalyani, A.

    2017-12-01

    Burn severity is a term used to describe the longer-term, second-order effects of fire on ecosystems. Plant communities are assumed to recover more slowly at higher burn severities; however, this likely depends on plant community type and climate. We assessed vegetation recovery approximately a decade post-fire across North American forests (moist mixed conifer, dry mixed conifer, ponderosa pine) and shrublands (mountain big sagebrush and Wyoming big sagebrush) distributed across climate and burn severity gradients. We assessed vegetation recovery across these ecosystems as indicated by the differenced Normalized Burn Ratio derived from 1984-2016 Landsat time series imagery (LandTrendr). Additionally, we used field vegetation measurements to examine local topographic controls on burn severity and post-fire vegetation recovery. Ecosystem responses were related to climate predictors derived from downscaled 1993-2011 climate normals. We hypothesized that drier and hotter ecosystems would take longer to recover. We also predicted areas with higher burn severity to have slower recovery. We found post-fire recovery to be strongly predicted by precipitation with the slowest recovery in shrublands and ponderosa pine forest, the driest vegetation types considered. We conclude that climate and burn severity interact to determine ecosystem recovery trajectories after fire, with burn severity having larger influence in the short term, and climate having larger influence in the long term.

  14. A 6 year longitudinal study of post-fire woody carbon dynamics in California's forests

    Treesearch

    Bianca N.I. Eskelson; Vicente J. Monleon; Jeremy S. Fried

    2016-01-01

    We examined the dynamics of aboveground forest woody carbon pools — live trees, standing dead trees, and down wood—during the first 6 years following wildfire across a wide range of conditions, which are characteristic of California forest fires. From repeated measurements of the same plots, we estimated change in woody carbon pools as a function of crown fire severity...

  15. Post-fire redistribution of soil carbon and nitrogen at a grassland-shrubland ecotone

    USGS Publications Warehouse

    Wang, Guan; Li, Junran; Ravi, Sujith; Dukes, David; Gonzales, Howell B.; Sankey, Joel B.

    2018-01-01

    The rapid conversion of grasslands into shrublands has been observed in many arid and semiarid regions worldwide. Studies have shown that fire can provide certain forms of reversibility for shrub-grass transition due to resource homogenization and shrub mortality, especially in the early stages of shrub encroachment. Field-level post-fire soil resource redistribution has rarely been tested. Here we used prescribed fire in a shrubland-grassland transition zone in the northern Chihuahuan Desert to test the hypothesis that fire facilitates the remobilization of nutrient-enriched soil from shrub microsites to grass and bare microsites and thereby reduces the spatial heterogeneity of soil resources. Results show that the shrub microsites had the lowest water content compared to grass and bare microsites after fire, even when rain events occurred. Significant differences of total soil carbon (TC) and total soil nitrogen (TN) among the three microsites disappeared one year after the fire. The spatial autocorrelation distance increased from 1~2 m, approximately the mean size of an individual shrub canopy, to over 5 m one year after the fire for TC and TN. Patches of high soil C and N decomposed one year after the prescribed fire. Overall, fire stimulates the transfer of soil C and N from shrub microsites to nutrient-depleted grass and bare microsites. Such a redistribution of soil C and N, coupled with the reduced soil water content under the shrub canopies, suggests that fire might influence the competition between shrubs and grasses, leading to a higher grass, compared to shrub, coverage in this ecotone.

  16. Do Wildfires Promote Woody Species Invasion in a Fire-Adapted Ecosystem? Post-fire Resprouting of Native and Non-native Woody Plants in Central Argentina.

    PubMed

    Herrero, M Lucrecia; Torres, Romina C; Renison, Daniel

    2016-02-01

    We asked whether prescribed fire could be a useful management tool to reduce invasion by non-native plants in an ecosystem where native plants are supposed to be adapted to fires. Specifically, we compare the post-fire resprouting response of native and non-native woody species in Chaco Serrano forest of central Argentina. The measurements were carried out in five burnt areas where we selected ten native and seven non-native species. Our response variables were (1) post-fire survival, (2) types of resprouts, and (3) the growth of the resprouts. Our main results show that one year after the fire, survivals of native and non-native species were 0.84 and 0.89, respectively, with variances in survival seven times smaller in the native species group. Type of resprout was also less variable in native species, while growth of the resprouts was similar in native and non-native groups. We interpret that in most cases, the burning a forest with mixed native and non-native plants through prescribed fires will not differentially stop the invasion by non-native woody species even in ecosystems which are presumed to be relatively resistant to fires such as our study area.

  17. Rapid Response Tools and Datasets for Post-fire Erosion Modeling: Lessons Learned from the Rock House and High Park Fires

    NASA Astrophysics Data System (ADS)

    Miller, Mary Ellen; Elliot, William E.; MacDonald, Lee H.

    2013-04-01

    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

  18. Finding simplicity in complexity: modelling post-fire hydrogeomorphic processes and risks

    NASA Astrophysics Data System (ADS)

    Sheridan, Gary; Langhans, Christoph; Lane, Patrick; Nyman, Petter

    2017-04-01

    Post-fire runoff and erosion can shape landscapes, destroy infrastructure, and result in the loss of human life. However even within seemingly similar geographic regions post-fire hydro-geomorphic responses vary from almost no response through to catastrophic flash floods and debris flows. Why is there so much variability, and how can we predict areas at risk? This presentation describes the research journey taken by the post-fire research group at The University of Melbourne to answer this question for the se Australian uplands. Key steps along the way have included identifying the dominant erosion processes (and their forcings), and the key system properties controlling the rates of these dominant processes. The high degree of complexity in the interactions between the forcings, the system properties, and the erosion processes, necessitated the development of a simplified conceptual representation of post-fire hydrogeomorphic system that was conducive to modelling and simulation. Spatially mappable metrics (and proxies) for key system forcings and properties were then required to parameterize and drive the model. Each step in this journey has depended on new research, as well as ongoing feedback from land and water management agencies tasked with implementing these risk models and interpreting the results. These models are now imbedded within agencies and used for strategic risk assessments, for tactical response during fires, and for post-fire remediation and risk planning. Reflecting on the successes and failures along the way provides for some more general insights into the process of developing research-based models for operational use by land and water management agencies.

  19. A decadal glimpse on climate and burn severity influences on ponderosa pine post-fire recovery

    NASA Astrophysics Data System (ADS)

    Newingham, B. A.; Hudak, A. T.; Bright, B. C.; Smith, A.; Khalyani, A. H.

    2016-12-01

    Climate change is predicted to affect plants at the margins of their distribution. Thus, ecosystem recovery after fire is likely to vary with climate and may be slowest in drier and hotter areas. However, fire regime characteristics, including burn severity, may also affect vegetation recovery. We assessed vegetation recovery one and 9-15 years post-fire in North American ponderosa pine ecosystems distributed across climate and burn severity gradients. Using climate predictors derived from downscaled 1993-2011 climate normals, we predicted vegetation recovery as indicated by Normalized Burn Ratio derived from 1984-2012 Landsat time series imagery. Additionally, we collected field vegetation measurements to examine local topographic controls on burn severity and post-fire vegetation recovery. At a regional scale, we hypothesized a positive relationship between precipitation and recovery time and a negative relationship between temperature and recovery time. At the local scale, we hypothesized southern aspects to recovery slower than northern aspects. We also predicted higher burn severity to slow recovery. Field data found attenuated ponderosa pine recovery in hotter and drier regions across all burn severity classes. We concluded that downscaled climate data and Landsat imagery collected at commensurate scales may provide insight into climate effects on post-fire vegetation recovery relevant to ponderosa pine forest managers.

  20. Post-fire regeneration in seasonally dry tropical forest fragments in southeastern Brazil.

    PubMed

    Costa, Mayke B; Menezes, Luis Fernando T DE; Nascimento, Marcelo T

    2017-01-01

    Seasonally dry tropical forest is one of the highly threatened biome. However, studies on the effect of fire on these tree communities are still scarce. In this context, a floristic and structural survey in three forest areas in the southeast of Brazil that were affected by fire between 14 and 25 years ago was performed with the objective of evaluating post-fire regeneration. In each site, five systematically placed plots (25 m x 25 m each) were established. The more recently burnt site had significantly lower values of richness and diversity than the other two sites. However, the sites did not differ in density and basal area. Annona dolabripetala, Astronium concinnum, Joannesia princeps and Polyandrococos caudescens were within the 10 most important species for the three sites. Comparing these data with adjacent mature forests, the results indicated differences both in structural and floristic aspects, suggesting that the time after fire was not sufficient for recuperation of these areas. The recovery process indicate at least 190 years for areas return to basal area values close to those observed in mature forests nearby.

  1. Detecting post-fire burn severity and vegetation recovery using multitemporal remote sensing spectral indices and field-collected composite burn index data in a ponderosa pine forest

    USGS Publications Warehouse

    Chen, Xuexia; Vogelmann, James E.; Rollins, Matt; Ohlen, Donald; Key, Carl H.; Yang, Limin; Huang, Chengquan; Shi, Hua

    2011-01-01

    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.

  2. Post-fire burn severity and vegetation response following eight large wildfires across the Western United States

    Treesearch

    Leigh B. Lentile; Penelope Morgan; Andrew T. Hudak; Michael J. Bobbitt; Sarah A. Lewis; Alistair M. S. Smith; Peter R. Robichaud

    2007-01-01

    Vegetation response and burn severity were examined following eight large wildfires that burned in 2003 and 2004: two wildfires in California chaparral, two each in dry and moist mixed-conifer forests in Montana, and two in boreal forests in interior Alaska. Our research objectives were: 1) to characterize one year post-fire vegetation recovery relative to initial fire...

  3. Successional changes in trophic interactions support a mechanistic model of post-fire population dynamics.

    PubMed

    Smith, Annabel L

    2018-01-01

    Models based on functional traits have limited power in predicting how animal populations respond to disturbance because they do not capture the range of demographic and biological factors that drive population dynamics, including variation in trophic interactions. I tested the hypothesis that successional changes in vegetation structure, which affected invertebrate abundance, would influence growth rates and body condition in the early-successional, insectivorous gecko Nephrurus stellatus. I captured geckos at 17 woodland sites spanning a succession gradient from 2 to 48 years post-fire. Body condition and growth rates were analysed as a function of the best-fitting fire-related predictor (invertebrate abundance or time since fire) with different combinations of the co-variates age, sex and location. Body condition in the whole population was positively affected by increasing invertebrate abundance and, in the adult population, this effect was most pronounced for females. There was strong support for a decline in growth rates in weight with time since fire. The results suggest that increased early-successional invertebrate abundance has filtered through to a higher trophic level with physiological benefits for insectivorous geckos. I integrated the new findings about trophic interactions into a general conceptual model of mechanisms underlying post-fire population dynamics based on a long-term research programme. The model highlights how greater food availability during early succession could drive rapid population growth by contributing to previously reported enhanced reproduction and dispersal. This study provides a framework to understand links between ecological and physiological traits underlying post-fire population dynamics.

  4. Evaluation of a post-fire tree mortality model for western US conifers

    Treesearch

    Sharon M. Hood; Charles W McHugh; Kevin C. Ryan; Elizabeth Reinhardt; Sheri L. Smith

    2007-01-01

    Accurately predicting fire-caused mortality is essential to developing prescribed fire burn plans and post-fire salvage marking guidelines. The mortality model included in the commonly used USA fire behaviour and effects models, the First Order Fire Effects Model (FOFEM), BehavePlus, and the Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS), has not...

  5. The Cooney Ridge Fire Experiment: An early operation to relate pre-, active, and post-fire field and remotely sensed measurements

    Treesearch

    Andrew T. Hudak; Patrick H. Freeborn; Sarah A. Lewis; Sharon M. Hood; Helen Y. Smith; Colin C. Hardy; Robert J. Kremens; Bret W. Butler; Casey Teske; Robert G. Tissell; Lloyd P. Queen; Bryce L. Nordgren; Benjamin C. Bright; Penelope Morgan; Philip J. Riggan; Lee Macholz; Leigh B. Lentile; James P. Riddering; Edward E. Mathews

    2018-01-01

    The Cooney Ridge Fire Experiment conducted by fire scientists in 2003 was a burnout operation supported by a fire suppression crew on the active Cooney Ridge wildfire incident. The fire experiment included measurements of pre-fire fuels, active fire behavior, and immediate post-fire effects. Heat flux measurements collected at multiple scales with multiple ground and...

  6. Post Fire Vegetation Recovery in Greece after the large Drought event of 2007

    NASA Astrophysics Data System (ADS)

    Gouveia, Célia M.; Bastos, Ana; DaCamara, Carlos; Trigo, Ricardo

    2013-04-01

    Fire is a natural factor of Mediterranean ecosystems. However, fire regimes in the European Mediterranean areas have been changing in the last decades, mainly due to land-use changes and climate driven factors possibly associated with climatic warming (e.g. decline of precipitation, increasing temperatures but also higher frequency of heatwaves). In Greece, the fire season of 2007 was particularly devastating, achieving the new all-time record of estimated burnt area (225 734 ha), since 1980. Additionally, we must stress that prior to the summer fire season in 2007, Greece suffered an exceptional drought event. This severe drought had a strong negative impact in vegetation dynamics. 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. Based on monthly values of NDVI, at the 1km×1km spatial scale, as obtained from the VEGETATION-SPOT5 instrument, from 1999 to 2010, large burnt scars are identified in Greece, during 2007 fire season. Vegetation recovery is then assessed based on a mono parametric regression model originally developed by Gouveia et al. (2010) to identify large burnt scars in Portugal during the 2003 fire season and after applied to 2005 fire season (Bastos et al., 2012). Some large burnt areas are selected and the respective NDVI behaviour is monitored throughout the pre and the post fire period. The vegetation dynamics during the pre-fire period is analysed and related to the extreme climatic events that characterised the considered period. An analysis is made of the dependence of recovery rates on land cover types and fire damage. Finally results are compared to results already obtained for Portugal (Gouveia et al. 2010). This work emphasises the use of a simple methodology, when applied to low resolution satellite imagery in order to monitor vegetation recovery after large fires events over

  7. Post-fire analysis of construction materials

    NASA Astrophysics Data System (ADS)

    Schroeder, Robert Allen

    The objective of this thesis is to determine and document the extent to which the fire damage in wood, concrete, and gypsum wallboard can be used to determine the time and heat flux exposure of the incipient stages of an uncontrolled fire event. A literature review outlines the state-of-the-art in three distinct areas: (1) Fire investigation; (2) The physical properties of wood, concrete, and gypsum wallboard, and (3) The fire response characteristics of those materials and their use in fire investigations. The results from quantitative experimental fire exposures of the subject materials are presented. The experiments were conducted under controlled conditions with the intent to develop standards for macroscopic and microscopic states of the materials for a given heat flux exposure and temperature. Standards and procedures are introduced for field sample collection, laboratory testing of the field samples, and interpretation of results. There are three major conclusions to be derived from this dissertation. The first two are that (1) wood and (2) concrete should not be viewed as reliable sources of information for a fire investigator to use for an analysis of how an actual fire ignited or spread. On the other hand the third major conclusion is that (3) gypsum wallboard can be considered a reliable source of information of fire behavior. The basis of each these conclusions is described in each of the chapters associated with each of the materials. One of the most important findings in this research is the use of X-ray diffraction to determine the maximum temperature reached by a sample of gypsum wallboard. Then by using the plots of isotherm progression it is possible to estimate the approximate length of exposure to a given heat flux. The use of gypsum-based post evidence is much more accurate than any available for wood or for concrete.

  8. Analyzing post-fire topography at the hillslope-channel interface with terrestrial LiDAR: contrasting geomorphic responses from the 2012 Waldo Canyon Fire of Colorado and the 2013 Springs Fire of California

    NASA Astrophysics Data System (ADS)

    Storesund, R.; Chin, A.; Florsheim, J. L.; O'Hirok, L.; Williams, K.; Austin, K. E.

    2014-12-01

    Mountains areas are increasingly susceptible to wildfires because of warming climates. Although knowledge of the hydro-geomorphological impacts of wildfire has advanced in recent years, much is still unknown regarding how environmental fluxes move through burned watersheds. Because of the loss of vegetation and hydrophobic soils, flash floods often accompany elevated runoff events from burned watersheds, making direct process measurements challenging. Direct measurements are also only partly successful at capturing the spatial variations of post-fire effects. Coupled with short temporal windows for observing such responses, opportunities are often missed for collecting data needed for developing predictive models. Terrestrial LiDAR scanning (TLS) of burned areas allows detailed documentation of the post-fire topography to cm-level accuracy, providing pictures of geomorphic responses not previously possible. This paper reports a comparative study of hillslope-channel interactions, using repeat TLS, in two contrasting environments. Burned by the 2012 Waldo Canyon Fire and 2013 Springs Fire, in Colorado and California respectively, the study sites share many similarities including steep erosive slopes, small drainage areas, and step-pool channel morphologies. TLS provided a tool to test the central hypothesis that, dry ravel, distinct in the California Mediterranean environment, would prompt a greater sedimentological response from the Springs Fire compared to the Waldo Canyon Fire. At selected sites in each area, TLS documented baseline conditions immediately following the fire. Repeat scanning after major storms allowed detection of changes in the landscape. Results show a tendency for sedimentation in river channels in the study sites interacting with dry ravel on hillslopes, whereas erosion dominated the response from the Waldo Canyon Fire with an absence of dry ravel. These data provide clues to developing generalizations for post-fire effects at regional scales

  9. Comparison of post-fire seedling establishment between scrub communities in mediterranean and non-mediterranean climate ecosystems

    USGS Publications Warehouse

    Carrington, M.E.; Keeley, J.E.

    1999-01-01

    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.

  10. Comparing fire severity models from post-fire and pre/post-fire differenced imagery

    USDA-ARS?s Scientific Manuscript database

    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...

  11. Relationship of post-fire ground cover to surface fuel loads and consumption in longleaf pine ecosystems

    Treesearch

    Andrew T. Hudak; Roger D. Ottmar; Robert E. Vihnanek; Clint S. Wright

    2014-01-01

    The RxCADRE research team collected multi-scale measurements of pre-, during, and post-fire variables on operational prescribed fires conducted in 2008, 2011, and 2012 in longleaf pine ecosystems in the southeastern USA. Pre- and post-fire surface fuel loads were characterized in alternating pre- and post-fire clip plots systematically established within burn units....

  12. Post-Fire soil water repellency, hydrologic response, and sediment yield compared between grass-converted and chaparral watersheds

    Treesearch

    Ken R. Hubbert; Pete M. Wohlgemuth; Jan L. Beyers; Marcia G. Narog; Ross Gerrard

    2012-01-01

    In 2002, the Williams Fire burned >90 % of the San Dimas Experimental Forest, providing an opportunity to investigate differences in soil water repellency, peak discharge, and sediment yield between grass-converted and chaparral watersheds. Post-fire water repellency and moisture content were measured in the winter and summer for four years. Peak discharge was...

  13. Chapter 4. Predicting post-fire erosion and sedimentation risk on a landscape scale

    USGS Publications Warehouse

    MacDonald, L.H.; Sampson, R.; Brady, D.; Juarros, L.; Martin, Deborah

    2000-01-01

    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.

  14. Soil microbiological properties and enzymatic activities of long-term post-fire recovery in dry and semiarid Aleppo pine (Pinus halepensis M.) forest stands

    NASA Astrophysics Data System (ADS)

    Hedo, J.; Lucas-Borja, M. E.; Wic, C.; Andrés Abellán, M.; de Las Heras, J.

    2014-10-01

    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.

  15. Soil microbiological properties and enzymatic activities of long-term post-fire recovery in dry and semiarid Aleppo pine (Pinus halepensis M.) forest stands

    NASA Astrophysics Data System (ADS)

    Hedo, J.; Lucas-Borja, M. E.; Wic, C.; Andrés-Abellán, M.; de Las Heras, J.

    2015-02-01

    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.

  16. Effectiveness of three post-fire rehabilitation treatments in the Colorado Front Range

    Treesearch

    J. W. Wagenbrenner; L. H. MacDonald; D. Rough

    2006-01-01

    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...

  17. Identifying key climate and environmental factors affecting rates of post-fire big sagebrush (Artemisia tridentata) recovery in the northern Columbia Basin, USA

    USGS Publications Warehouse

    Shinneman, Douglas; McIlroy, Susan

    2016-01-01

    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.

  18. Topography and climate are more important drivers of long-term, post-fire vegetation assembly than time-since-fire in the Sonoran Desert, US

    USGS Publications Warehouse

    Shryock, Daniel F.; Esque, Todd C.; Chen, Felicia

    2015-01-01

    We find substantial evidence that environmental filters, rather than TSF, drive the majority of variability in long-term, post-fire vegetation assembly within the Sonoran Desert. Careful consideration of spatial variability in abiotic conditions may benefit post-fire vegetation modelling, as well as fire management and restoration strategies.

  19. Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland.

    PubMed

    Kraaij, Tineke; Cowling, Richard M; van Wilgen, Brian W; Rikhotso, Diba R; Difford, Mark

    2017-01-01

    Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa) where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents) of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire) fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed 'recruitment'). Factors (in decreasing order of importance) affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire) and fire return interval (>7 years) had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2-3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting that proteoid

  20. Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland

    PubMed Central

    Cowling, Richard M.; van Wilgen, Brian W.; Rikhotso, Diba R.; Difford, Mark

    2017-01-01

    Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa) where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents) of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire) fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed ‘recruitment’). Factors (in decreasing order of importance) affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire) and fire return interval (>7 years) had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2–3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting that proteoid

  1. Assessing post-fire Douglas-fir mortality and Douglas-fir beetle attacks in the northern Rocky Mountains

    Treesearch

    Sharon Hood; Barbara Bentz; Ken Gibson; Kevin Ryan; Gregg DeNitto

    2007-01-01

    Douglas-fir has life history traits that greatly enhance resistance to injury from fire, thereby increasing post-fire survival rates. Tools for predicting the probability of tree mortality following fire are important components of both pre-fire planning and post-fire management efforts. Using data from mixed-severity wildfire in Montana and Wyoming, Hood and Bentz (...

  2. Compressive properties of post-fire strain hardening cementitious composites

    NASA Astrophysics Data System (ADS)

    Yu, Dianyou; Xu, Zhichao; Liu, Yingchun

    2018-03-01

    In present research, the influence of post-fire curing methods on the mechanical properties of fire-damaged UHTCC was investigated. A heating temperature up to 800°C and lasting for 2 hours was adopted to simulate the fire damage, after which, the heated specimens were subjected to three types of cooling regimes (i.e., 1.cooling in air, 2. quenching in water for 5 minutes, and 3. quenching in water for 30 minutes). It was found that quenching in water helped the recovery of the compressive properties of UHTCC.

  3. Post-Fire Recovery of Eco-Hydrologic Behavior Given Historic and Projected Climate Variability in California Mediterranean Type Environments

    NASA Astrophysics Data System (ADS)

    Seaby, L. P.; Tague, C. L.; Hope, A. S.

    2006-12-01

    The Mediterranean type environments (MTEs) of California are characterized by a distinct wet and dry season and high variability in inter-annual climate. Water limitation in MTEs makes eco-hydrological processes highly sensitive to both climate variability and frequent fire disturbance. This research modeled post-fire eco- hydrologic behavior under historical and moderate and extreme scenarios of future climate in a semi-arid chaparral dominated southern California MTE. We used a physically-based, spatially-distributed, eco- hydrological model (RHESSys - Regional Hydro-Ecologic Simulation System), to capture linkages between water and vegetation response to the combined effects of fire and historic and future climate variability. We found post-fire eco-hydrologic behavior to be strongly influenced by the episodic nature of MTE climate, which intensifies under projected climate change. Higher rates of post-fire net primary productivity were found under moderate climate change, while more extreme climate change produced water stressed conditions which were less favorable for vegetation productivity. Precipitation variability in the historic record follows the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), and these inter-annual climate characteristics intensify under climate change. Inter-annual variation in streamflow follows these precipitation patterns. Post-fire streamflow and carbon cycling trajectories are strongly dependent on climate characteristics during the first 5 years following fire, and historic intra-climate variability during this period tends to overwhelm longer term trends and variation that might be attributable to climate change. Results have implications for water resource availability, vegetation type conversion from shrubs to grassland, and changes in ecosystem structure and function.

  4. How long will my reservoir be contaminated following a post-fire erosion event?

    NASA Astrophysics Data System (ADS)

    Schärer, Christine; Yeates, Peter; Sheridan, Gary; Doerr, Stefan; Nyman, Petter; Langhans, Christoph; Haydon, Shane; Santin, Cristina

    2017-04-01

    Post fire erosion processes such as debris flows can generate large volumes of sediment, contaminating streams and reservoirs for extended periods. Recent research has enabled the magnitude of the generated load to be reasonably estimated, but what happens once this load of sediment and ash reaches the reservoir? Water treatment plants typically have a threshold contaminant level, above which the treatment capacity is exceeded and the water becomes undeliverable. As hydrologists, soils scientists and geomorphologists we think in terms of volumes of water and masses of sediment, but for water managers the metric that really matters is "How many days will my reservoir be unable to supply water, and what is the chance of that occurring?" Answering this question is difficult as it involves modelling the weather, the fire regime, the post fire hydrology and erosion processes, and finally the hydrodynamics of the reservoir so to be able to predict the propagation of the contaminant plume from the entry point to the reservoir take off point. These models are numerically intensive, and this study develops a new method to combine these models in a way that allows them to be implemented within a Monte Carlo simulation. The new approach was applied to the case study of the Upper Yarra reservoir in south east Australia, the main water supply for Melbourne's 4M residents. The results indicate that following fire water managers should be prepared for post-fire reservoir contamination events extending from several months to more than a year. The duration of the contamination events was found to be extremely sensitive to the quantity, size distribution, and density of the <5um particles of ash and soil, which makes up a small fraction of the total debris flow load.

  5. Hydrological modelling for flood forecasting: Calibrating the post-fire initial conditions

    NASA Astrophysics Data System (ADS)

    Papathanasiou, C.; Makropoulos, C.; Mimikou, M.

    2015-10-01

    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

  6. The importance of mammalian torpor for survival in a post-fire landscape.

    PubMed

    Stawski, Clare; Körtner, Gerhard; Nowack, Julia; Geiser, Fritz

    2015-06-01

    Wildfires have increased in frequency and intensity worldwide with climate change as a main driving factor. While a number of studies have focused on population changes in regard to fires, there are essentially no quantitative data on behavioural and physiological adjustments that are vital for the persistence of individuals during and after fires. Here we show that brown antechinus, a small insectivorous marsupial mammal, (i) endured a prescribed fire in situ, (ii) remained in their scorched home range despite unburned areas nearby, and (iii) substantially increased post-fire torpor use and thus reduced foraging requirements and exposure to predators. Hence, torpor is a physiological adaptation that, although not quantified in this context previously, appears to play a key role in post-fire survival for this and other heterothermic species. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  7. The impact of post-fire salvage logging on microbial nitrogen cyclers in Mediterranean forest soil.

    PubMed

    Pereg, Lily; Mataix-Solera, Jorge; McMillan, Mary; García-Orenes, Fuensanta

    2018-04-01

    Forest fires are a regular occurrence in the Mediterranean basin. High severity fires and post-fire management can affect biological, chemical and physical properties of soil, including the composition and abundance of soil microbial communities. Salvage logging is a post-fire management strategy, which involves the removal of burnt wood from land after a fire. The main objective of this work was to evaluate the impact of post-fire salvage logging and microaggregation on soil microbial communities, specifically on the abundance of nitrogen cyclers and, thus, the potential of the soil for microbial nitrogen cycling. The abundance of nitrogen cyclers was assessed by quantification of microbial nitrogen cycling genes in soil DNA, including nifH (involved in nitrogen fixation), nirS/K and nosZ (involved in denitrification), amoA-B and amoA-Arch (involved in bacterial and archaeal nitrification, respectively). It was demonstrated that salvage logging reduced bacterial load post-fire when compared to tree retention control and resulted in significant changes to the abundance of functional bacteria involved in nitrogen cycling. Microbial gene pools involved in various stages of the nitrogen cycle were larger in control soil than in soil subjected to post-fire salvage logging and were significantly correlated with organic matter, available phosphorous, nitrogen and aggregate stability. The microaggregate fraction of the soil, which has been associated with greater organic carbon, was shown to be a hotspot for nitrogen cyclers particularly under salvage logging. The impact of post-fire management strategies on soil microbial communities needs to be considered in relation to maintaining ecosystem productivity, resilience and potential impact on climate change. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Post-fire monitoring of coast live oaks (Quercus agrifolia) burned in the 1993 Old Topanga Fire

    Treesearch

    Rosi Dagit

    2002-01-01

    The intensity of the 1993 Old Topanga Fire raised many concerns about the recovery and response of the coast live oak trees (Quercus agrifolia) and their understory vegetation. Preliminary information on the status of the trees 6 months post-fire has been previously reported. This report provides follow up assessment of the condition of the 90 trees...

  9. Assessment of Post Forest Fire Landslides in Uttarakhand Himalaya, India

    NASA Astrophysics Data System (ADS)

    Sharma, N.; Singh, R. B.

    2017-12-01

    According to Forest Survey of India-State Forest Report (2015), the total geographical area of Uttarakhand is 53, 483 covers km2 out of which 24,402 km2 area covers under total forest covers. As noticed during last week of April, 2016 forest of Uttarakhand mountains was gutted down due to major incidences of fire. This incident caused huge damage to different species of flora-fauna, human being, livestock, property and destruction of mountain ecosystem. As per media reports, six people were lost their lives and recorded several charred carcasses of livestock's due to this incident. The forest fire was affected the eleven out of total thirteen districts which roughly covers the 0.2% (approx.) of total vegetation covers.The direct impact of losses are easy to be estimated but indirect impacts of this forest fire are yet to be occurred. The threat of post Forest fire induced landslides during rainfall is themain concern. Since, after forest fire top soil and rocks are loose due to loss of vegetation as binding and protecting agent against rainfall. Therefore, the pore water pressure and weathering will be very high during rainy season which can cause many landslides in regions affected by forest fire. The demarcation of areas worse affected by forest fire is necessary for issuing alerts to habitations and important infrastructures. These alerts will be based upon region specific probable rainfall forecasting through Indian Meteorological Department (IMD). The main objective is to develop a tool for detecting early forest fire and to create awareness amongst mountain community, researchers and concerned government agencies to take an appropriate measures to minimize the incidences of Forest fire and impact of post forest fire landslides in future through implementation of sustainable mountain strategy.

  10. Post-fire logging reduces surface woody fuels up to four decades following wildfire

    Treesearch

    David W. Peterson; Erich Kyle Dodson; Richy J. Harrod

    2015-01-01

    Severe wildfires create pulses of dead trees that influence future fuel loads, fire behavior, and fire effects as they decay and deposit surface woody fuels. Harvesting fire-killed trees may reduce future surface woody fuels and related fire hazards, but the magnitude and timing of post-fire logging effects on woody fuels have not been fully assessed. To address this...

  11. Risk of post-fire metal mobilization into surface water resources: A review.

    PubMed

    Abraham, Joji; Dowling, Kim; Florentine, Singarayer

    2017-12-01

    One of the significant economic benefits to communities around the world of having pristine forest catchments is the supply of substantial quantities of high quality potable water. This supports a saving of around US$ 4.1 trillion per year globally by limiting the cost of expensive drinking water treatments and provision of unnecessary infrastructure. Even low levels of contaminants specifically organics and metals in catchments when in a mobile state can reduce these economic benefits by seriously affecting the water quality. Contamination and contaminant mobility can occur through natural and anthropogenic activities including forest fires. Moderate to high intensity forest fires are able to alter soil properties and release sequestered metals from sediments, soil organic matter and fragments of vegetation. In addition, the increase in post-fire erosion rate by rainfall runoff and strong winds facilitates the rapid transport of these metals downslope and downstream. The subsequent metal deposition in distal soil and water bodies can influence surface water quality with potential impacts to the larger ecosystems inclusive of negative effects on humans. This is of substantial concern as 4 billion hectares of forest catchments provide high quality water to global communities. Redressing this problem requires quantification of the potential effects on water resources and instituting rigorous fire and environmental management plans to mitigate deleterious effects on catchment areas. This paper is a review of the current state of the art literature dealing with the risk of post-fire mobilization of the metals into surface water resources. It is intended to inform discussion on the preparation of suitable management plans and policies during and after fire events in order to maintain potable water quality in a cost-effective manner. In these times of climate fluctuation and increased incidence of fires, the need for development of new policies and management frameworks

  12. Using bark char codes to predict post-fire cambium mortality

    Treesearch

    Sharon M. Hood; Danny R. Cluck; Sheri L. Smith; Kevin C. Ryan

    2008-01-01

    Cambium injury is an important factor in post-fire tree survival. Measurements that quantify the degree of bark charring on tree stems after fire are often used as surrogates for direct cambium injury because they are relatively easy to assign and are non-destructive. However, bark char codes based on these measurements have been inadequately tested to determine how...

  13. Post-fire soil functionality and microbial community structure in a Mediterranean shrubland subjected to experimental drought.

    PubMed

    Hinojosa, M Belén; Parra, Antonio; Laudicina, Vito Armando; Moreno, José M

    2016-12-15

    Fire may cause significant alterations in soil properties. Post-fire soil dynamics can vary depending, among other factors, on rainfall patterns. However, little is known regarding variations in response to post-fire drought. This is relevant in arid and semiarid areas with poor soils, like much of the western Mediterranean. Furthermore, climate change projections in such areas anticipate reduced precipitation and longer annual drought periods, together with an increase in fire severity and frequency. This research evaluates the effects of experimental drought after fire on soil dynamics of a Cistus-Erica shrubland (Central Spain). A replicated (n=4) field experiment was conducted in which the total rainfall and its patterns were manipulated by means of a rain-out shelters and irrigation system. The treatments were: environmental control (natural rainfall), historical control (average rainfall, 2months drought), moderate drought (25% reduction of historical control, 5months drought) and severe drought (45% reduction, 7months drought). After one growing season under these rainfall treatments, the plots were burned. One set of unburned plots under natural rainfall served as an additional control. Soils were collected seasonally. Fire increased soil P and N availability. Post-fire drought treatments reduced available soil P but increased N concentration (mainly nitrate). Fire reduced available K irrespective of drought treatments. Fire reduced enzyme activities and carbon mineralization rate, a reduction that was higher in post-fire drought-treated soils. Fire decreased soil microbial biomass and the proportion of fungi, while that of actinomycetes increased. Post-fire drought decreased soil total microbial biomass and fungi, with bacteria becoming more abundant. Our results support that increasing drought after fire could compromise the resilience of Mediterranean ecosystems to fire. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Fire frequency, area burned, and severity: A quantitative approach to defining a normal fire year

    USGS Publications Warehouse

    Lutz, J.A.; Key, C.H.; Kolden, C.A.; Kane, J.T.; van Wagtendonk, J.W.

    2011-01-01

    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.

  15. Utilizing Remote Sensing Information to Improve Post-fire Rainfall-runoff Predictions after the 2010 Bull Fire in the Sequoia National Forest, CA

    NASA Astrophysics Data System (ADS)

    Kinoshita, A. M.; Hale, B.; Hogue, T. S.

    2012-12-01

    Post-fire management decisions are guided by rainfall-runoff predictions, which ultimately influence downstream treatment and mitigation costs. The current study investigates evolving rainfall-runoff partitioning at the watershed scale over a two-year period after the 2010 Bull Fire which occurred in the southern Sequoia National Forest in California. Stage height was measured at five-minute intervals using pressure transducers, tipping buckets were installed for rainfall duration and intensity, and channel cross-sections were measured approximately every two months to detail sediment deposition or scour. We also utilize remotely sensed vegetation data to evaluate vegetation recovery in the studied watersheds and the corresponding relationship to storm runoff. Normalized Difference Vegetation Index (NDVI), a measure of vegetation greenness, is evaluated for its potential use as a key recovery indicator. Preliminary results focus on alterations in annual and seasonal precipitation and discharge relationships using in-situ data and Landsat NDVI values for the period of study. NDVI values are consistent with a comprehensive burn, with an acute decrease observed in the initial post-fire period. However, vegetation recovery is highly variable in the studied systems and influenced by shorter-term biomass pulses (grasses) while longer-term recovery of other species (chaparral and pine) is ongoing. Runoff ratios are elevated during early storms and show some recovery in the later part of the study period. The ability to accurately and confidently predict post-fire runoff and longer-term recovery is critical for monitoring values-at-risk, reducing mitigation costs, and improving warnings to downstream public communities.

  16. The influence of burn severity on post-fire vegetation recovery and albedo change during early succession in North American boreal forests

    NASA Astrophysics Data System (ADS)

    Jin, Y.; Randerson, J. T.; Goetz, S. J.; Beck, P. S.; Loranty, M. M.; Goulden, M.

    2011-12-01

    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.

  17. Spike Train Auto-Structure Impacts Post-Synaptic Firing and Timing-Based Plasticity

    PubMed Central

    Scheller, Bertram; Castellano, Marta; Vicente, Raul; Pipa, Gordon

    2011-01-01

    Cortical neurons are typically driven by several thousand synapses. The precise spatiotemporal pattern formed by these inputs can modulate the response of a post-synaptic cell. In this work, we explore how the temporal structure of pre-synaptic inhibitory and excitatory inputs impact the post-synaptic firing of a conductance-based integrate and fire neuron. Both the excitatory and inhibitory input was modeled by renewal gamma processes with varying shape factors for modeling regular and temporally random Poisson activity. We demonstrate that the temporal structure of mutually independent inputs affects the post-synaptic firing, while the strength of the effect depends on the firing rates of both the excitatory and inhibitory inputs. In a second step, we explore the effect of temporal structure of mutually independent inputs on a simple version of Hebbian learning, i.e., hard bound spike-timing-dependent plasticity. We explore both the equilibrium weight distribution and the speed of the transient weight dynamics for different mutually independent gamma processes. We find that both the equilibrium distribution of the synaptic weights and the speed of synaptic changes are modulated by the temporal structure of the input. Finally, we highlight that the sensitivity of both the post-synaptic firing as well as the spike-timing-dependent plasticity on the auto-structure of the input of a neuron could be used to modulate the learning rate of synaptic modification. PMID:22203800

  18. Post-fire grazing management in the Great Basin

    USDA-ARS?s Scientific Manuscript database

    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...

  19. Phenotypic plasticity of post-fire activity and thermal biology of a free-ranging small mammal.

    PubMed

    Stawski, Clare; Körtner, Gerhard; Nowack, Julia; Geiser, Fritz

    2016-05-15

    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. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Effects of post-fire soil hydrophobicity on inorganic soil nitrogen and sulfur cycling

    USDA-ARS?s Scientific Manuscript database

    Fire plays an important role in many native ecosystems, and its suppression has increased woody encroachment across the globe. Restoring native herbaceous communities following fire in encroached systems is often challenging. Post-fire soil hydrophobicity is one factor that may further limit site re...

  1. Engaging communities in post-fire restoration: forest treatments and community-agency relations after the Cerro Grande fire

    Treesearch

    Robert L. Ryan; Elisabeth M. Hamin

    2006-01-01

    Our research provides advice to managers in their work in post-fire forest rehabilitation based on focus groups and interviews in the Los Alamos, New Mexico, community after the Cerro Grande fire of 2000. We address two key issues: how different restoration efforts compare to natural revegetation from the public?s perspective, and how to effectively communicate with...

  2. Post-fire logging produces minimal persistent impacts on understory vegetation in northeastern Oregon, USA

    Treesearch

    David W. Peterson; Erich Dodson

    2016-01-01

    Post-fire forest management commonly requires accepting some negative ecological impacts from management activities in order to achieve management objectives. Managers need to know, however, whether ecological impacts from post-fire management activities are transient or cause long-term ecosystem degradation. We studied the long-term response of understory vegetation...

  3. Vegetation shifts observed in arctic tundra 17 years after fire

    USGS Publications Warehouse

    Barrett, Kirsten; Rocha, Adrian V.; van de Weg, Martine Janet; Shaver, Gaius

    2012-01-01

    With anticipated climate change, tundra fires are expected to occur more frequently in the future, but data on the long-term effects of fire on tundra vegetation composition are scarce. This study addresses changes in vegetation structure that have persisted for 17 years after a tundra fire on the North Slope of Alaska. Fire-related shifts in vegetation composition were assessed from remote-sensing imagery and ground observations of the burn scar and an adjacent control site. Early-season remotely sensed imagery from the burn scar exhibits a low vegetation index compared with the control site, whereas the late-season signal is slightly higher. The range and maximum vegetation index are greater in the burn scar, although the mean annual values do not differ among the sites. Ground observations revealed a greater abundance of moss in the unburned site, which may account for the high early growing season normalized difference vegetation index (NDVI) anomaly relative to the burn. The abundance of graminoid species and an absence of Betula nana in the post-fire tundra sites may also be responsible for the spectral differences observed in the remotely sensed imagery. The partial replacement of tundra by graminoid-dominated ecosystems has been predicted by the ALFRESCO model of disturbance, climate and vegetation succession.

  4. Monitoring post-fire changes in species composition and stand structure in boreal forests using high-resolution, 3-D aerial drone data and Landsat

    NASA Astrophysics Data System (ADS)

    Alonzo, M.; Morton, D. C.; Cook, B.; Andersen, H. E.; Mack, M. C.

    2017-12-01

    The growing frequency and severity of boreal forest fires has important consequences for fire carbon emissions and ecosystem composition. Severe fires are typically associated with high degrees of both canopy and soil organic layer (SOL) consumption, particularly in black spruce stands. Complete canopy consumption can decrease the likelihood of spruce regeneration due to reduced viability of the aerial seedbank. Deeper burning of the SOL increases fire emissions and can expose mineral soil that promotes colonization by broadleaf species. There is mounting evidence that a disturbance-driven shift from spruce to broadleaf forests may indicate an ecological state change with feedbacks to regional and global climate. If post-fire successional dynamics can be characterized at an ecosystem scale using remote sensing data, we will be better equipped to constrain carbon and energy fluxes from SOL losses and albedo changes. In this study, we used Landsat time series, very high-resolution structure-from-motion (SFM) drone imagery, and field measurements to investigate post-fire regrowth 13 years after the 2004 Taylor Complex (TC) fires in interior Alaska. Twenty-seven TC plots span a gradient of moisture conditions and burn severity as estimated by loss of SOL. A range of variables potentially governing seedling species dominance (e.g., moisture status, distance to seed sources) have been collected systematically over the years following fire. In July 2017, we additionally collected < 2 cm resolution drone imagery over 25 of the TC plots. We processed these highly overlapped, nadir-view and oblique angle photos into extremely dense (>700 pts/m2) RGB-colored point clouds using SFM techniques. With these point clouds and high resolution orthomosaics, we estimated: 1) snag heights and biomass, 2) remnant snag fine branching, and 3) species and structure of shrubs and groundcover that have regrown since fire. We additionally assembled a dense Landsat time series arranged by day-of-year

  5. Using remote sensing to monitor post-fire watershed recovery as a tool for management

    Treesearch

    Jess Clark; Marc Stamer; Kevin Cooper; Carolyn Napper; Terri Hogue; Alicia Kinoshita

    2013-01-01

    Post-fire watershed recovery is influenced by numerous variables but one of the most important factors is the rate of re-establishment of vegetative cover. Burned Area Emergency Response (BAER) teams, along with other agencies (Natural Resource Conservation Service, state, counties, cities, etc.), prescribe temporary post-fire mitigation treatments based on expected...

  6. Predicting post-fire tree mortality for 14 conifers in the Pacific Northwest, USA: Model evaluation, development, and thresholds

    Treesearch

    Lindsay M. Grayson; Robert A. Progar; Sharon M. Hood

    2017-01-01

    Fire is a driving force in the North American landscape and predicting post-fire tree mortality is vital to land management. Post-fire tree mortality can have substantial economic and social impacts, and natural resource managers need reliable predictive methods to anticipate potential mortality following fire events. Current fire mortality models are limited to a few...

  7. Post-fire geomorphic response in steep, forested landscapes: Oregon Coast Range, USA

    NASA Astrophysics Data System (ADS)

    Jackson, Molly; Roering, Joshua J.

    2009-06-01

    The role of fire in shaping steep, forested landscapes depends on a suite of hydrologic, biologic, and geological characteristics, including the propensity for hydrophobic soil layers to promote runoff erosion during subsequent rainfall events. In the Oregon Coast Range, several studies postulate that fire primarily modulates sediment production via root reinforcement and shallow landslide susceptibility, although few studies have documented post-fire geomorphic response. Here, we describe field observations and topographic analyses for three sites in the central Oregon Coast Range that burned in 1999, 2002, and 2003. The fires generated strongly hydrophobic soil layers that did not promote runoff erosion because the continuity of the layers was interrupted by pervasive discontinuities that facilitated rapid infiltration. At each of our sites, fire generated significant colluvial transport via dry ravel, consistent with other field-based studies in the western United States. Fire-driven dry ravel accumulation in low-order valleys of our Sulphur Creek site equated to a slope-averaged landscape lowering of 2.5 mm. Given Holocene estimates of fire frequency, these results suggest that fire may contribute 10-20% of total denudation across steep, dissected portions of the Oregon Coast Range. In addition, we documented more rapid decline of root strength at our sites than has been observed after timber harvest, suggesting that root strength was compromised prior to fire or that intense heat damaged roots in the shallow subsurface. Given that fire frequencies in the Pacific Northwest are predicted to increase with continued climate change, our findings highlight the importance of fire-induced dry ravel and post-fire debris flow activity in controlling sediment delivery to channels.

  8. Mapping Live Fuel Moisture and the relation to drought and post fire events for Southern California region

    NASA Astrophysics Data System (ADS)

    Hatzopoulos, N.; Kim, S. H.; Kafatos, M.; Nghiem, S. V.; Myoung, B.

    2016-12-01

    Live Fuel Moisture is a dryness measure used by the fire departments to determine how dry is the current situation of the fuels from the forest areas. In order to map Live Fuel Moisture we conducted an analysis with a standardized regressional approach from various vegetation indices derived from remote sensing data of MODIS. After analyzing the results we concluded mapping Live Fuel Moisture using a standardized NDVI product. From the mapped remote sensed product we observed the appearance of extremely high dry fuels to be highly correlated with very dry years based on the overall yearly precipitation. The appearances of the extremely dry mapped fuels tend to have a direct association with fire events and observed to be a post fire indicator. In addition we studied the appearance of extreme dry fuels during critical months when season changes from spring to summer as well as the relation to fire events.

  9. Are post-fire silvicultural treatments a useful tool to fight the climate change threat in terms of plant diversity?

    NASA Astrophysics Data System (ADS)

    Hedo de Santiago, Javier; Esteban Lucasr Borja, Manuel; de las Heras, Jorge

    2016-04-01

    Adaptative forest management demands a huge scientific knowledge about post-fire vegetation dynamics, taking into account the current context of global change. We hypothesized that management practices should be carry out taking into account the climate change effect, to obtain better results in the biodiversity maintenance across time. All of this with respect to diversity and species composition of the post-fire naturally regenerated Aleppo pine forests understory. The study was carried out in two post-fire naturally regenerated Aleppo pine forests in the Southeastern of the Iberian Peninsula, under contrasting climatic conditions: Yeste (Albacete) shows a dry climate and Calasparra (Murcia) shows a semiarid climate. Thinning as post-fire silvicultural treatment was carried out five years after the wildfire event, in the year 1999. An experiment of artificial drought was designed to evacuate 15% of the natural rainfall in both sites, Yeste and Calasparra, to simulate climate change. Taking into account all the variables (site, silvicultural treatment and artificial drought), alpha diversity indices including species richness, Shannon and Simpson diversity indices, and plant cover, were analyzed as a measure of vegetation abundance. The results showed that plant species were affected by thinning, whereas induced drought affected total cover and species, with lower values at Yeste. Significant site variation was also observed in soil properties, species richness and total plant cover, conversely to the plant species diversity indices. We conclude that the plant community shows different responses to a simulated environment of climate change depending on the experimental site.

  10. Stem demography and post-fire recruitment of a resprouting serotinous conifer

    USGS Publications Warehouse

    Keeley, J.E.; Keeley, M.B.; Bond, W.J.

    1999-01-01

    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

  11. A one year post-fire biogeochemical cycling record of a sandstone mountain fynbos ecosystem, South Africa

    NASA Astrophysics Data System (ADS)

    Bergh, E.; Compton, J. S.

    2012-04-01

    The Cape Floristic Region (CFR) in southwestern South Africa is a Mediterranean-type ecosystem dominated by highly diverse and endemic fynbos vegetation. In this study, the chemistry of rainwater (total wet and dry deposition), stream water and soil saturated paste extracts of the sandstone fynbos biome of the Kogelberg Biosphere Reserve reveals how the cycling of Cl, Na, SO4,Mg, Ca and K varied over a one year period following a major fire event. Fire is a critical component of fynbos ecology, but the fynbos ecosystem is under threat as the fire return frequency increases as a result of human activities. The underlying bedrock geology of the sandstone fynbos biome is dominated by quartz-rich (>97 wt% SiO2) sandstone providing few nutrients to the overlying thin (2 to 20 cm), acidic soils. Additional sources of nutrients to the ecosystem are derived from windblown marine and dust (consisting of minerals, organic matter and fire ash) aerosols. Rainout of marine aerosols decreases away from the coast. The delivery of marine aerosols (Cl, Na, SO4and Mg) corresponds with summer southerly winds from the ocean and windblown dust (SO4,Mg, Ca and K) is delivered through winter northerly winds from the continental interior. Remineralization of organic matter, dissolution of fire ash and chemical weathering of clay minerals derived from the bedrock and from windblown minerals provide additional sources of nutrients to the vegetation. Salts accumulated within and on top of soil surfaces during the dry summer period are washed into streams during the wet winter months. Afromontane forests occur within deep rocky ravines cut by mountain streams and are protected from fire. The afromontane vegetation did not burn during the fire and benefited from the release of nutrients but regrowth of fynbos on open burnt slopes was slow and most of the released nutrients were lost via streams. Fynbos regrowth largely reflected the hydrology of the study area and corresponded to the pre-fire

  12. Measuring short-term post-fire forest recovery across a burn severity gradient in a mixed pine-oak forest using multi-sensor remote sensing techniques

    DOE PAGES

    Meng, Ran; Wu, Jin; Zhao, Feng; ...

    2018-06-01

    Understanding post-fire forest recovery is pivotal to the study of forest dynamics and global carbon cycle. Field-based studies indicated a convex response of forest recovery rate to burn severity at the individual tree level, related with fire-induced tree mortality; however, these findings were constrained in spatial/temporal extents, while not detectable by traditional optical remote sensing studies, largely attributing to the contaminated effect from understory recovery. For this work, we examined whether the combined use of multi-sensor remote sensing techniques (i.e., 1m simultaneous airborne imaging spectroscopy and LiDAR and 2m satellite multi-spectral imagery) to separate canopy recovery from understory recovery wouldmore » enable to quantify post-fire forest recovery rate spanning a large gradient in burn severity over large-scales. Our study was conducted in a mixed pine-oak forest in Long Island, NY, three years after a top-killing fire. Our studies remotely detected an initial increase and then decline of forest recovery rate to burn severity across the burned area, with a maximum canopy area-based recovery rate of 10% per year at moderate forest burn severity class. More intriguingly, such remotely detected convex relationships also held at species level, with pine trees being more resilient to high burn severity and having a higher maximum recovery rate (12% per year) than oak trees (4% per year). These results are one of the first quantitative evidences showing the effects of fire adaptive strategies on post-fire forest recovery, derived from relatively large spatial-temporal domains. Our study thus provides the methodological advance to link multi-sensor remote sensing techniques to monitor forest dynamics in a spatially explicit manner over large-scales, with important implications for fire-related forest management, and for constraining/benchmarking fire effect schemes in ecological process models.« less

  13. Measuring short-term post-fire forest recovery across a burn severity gradient in a mixed pine-oak forest using multi-sensor remote sensing techniques

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Meng, Ran; Wu, Jin; Zhao, Feng

    Understanding post-fire forest recovery is pivotal to the study of forest dynamics and global carbon cycle. Field-based studies indicated a convex response of forest recovery rate to burn severity at the individual tree level, related with fire-induced tree mortality; however, these findings were constrained in spatial/temporal extents, while not detectable by traditional optical remote sensing studies, largely attributing to the contaminated effect from understory recovery. For this work, we examined whether the combined use of multi-sensor remote sensing techniques (i.e., 1m simultaneous airborne imaging spectroscopy and LiDAR and 2m satellite multi-spectral imagery) to separate canopy recovery from understory recovery wouldmore » enable to quantify post-fire forest recovery rate spanning a large gradient in burn severity over large-scales. Our study was conducted in a mixed pine-oak forest in Long Island, NY, three years after a top-killing fire. Our studies remotely detected an initial increase and then decline of forest recovery rate to burn severity across the burned area, with a maximum canopy area-based recovery rate of 10% per year at moderate forest burn severity class. More intriguingly, such remotely detected convex relationships also held at species level, with pine trees being more resilient to high burn severity and having a higher maximum recovery rate (12% per year) than oak trees (4% per year). These results are one of the first quantitative evidences showing the effects of fire adaptive strategies on post-fire forest recovery, derived from relatively large spatial-temporal domains. Our study thus provides the methodological advance to link multi-sensor remote sensing techniques to monitor forest dynamics in a spatially explicit manner over large-scales, with important implications for fire-related forest management, and for constraining/benchmarking fire effect schemes in ecological process models.« less

  14. Measurement and prediction of post-fire erosion at the hillslope scale, Colorado Front Range

    Treesearch

    Juan de Dios Benavides-Solorio; Lee H. MacDonald

    2005-01-01

    Post-fire soil erosion is of considerable concern because of the potential decline in site productivity and adverse effects on downstream resources. For the Colorado Front Range there is a paucity of post-fire erosion data and a corresponding lack of predictive models. This study measured hillslope-scale sediment production rates and site characteristics for three wild...

  15. Post-Fire Soil Respiration in Relation to the Burnt Wood Management

    NASA Astrophysics Data System (ADS)

    Marañón Jiménez, Sara; Castro, J.; Kowalski, A.; Serrano-Ortiz, P.; Ruiz, B.; Sancez-Canete, Ep; Zamora, R.

    2010-05-01

    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

  16. Fungal role in post-fire ecosystem recovery in Sierra Nevada National Park (Spain)

    NASA Astrophysics Data System (ADS)

    Bárcenas-Moreno, Gema; Jiménez-Morillo, Nicasio T.; Mataix-Beneyto, Jorge; Martín Sánchez, Ines

    2016-04-01

    Fire effect on soil microorganisms has been studies for decades in several ecosystems and different microbial response can be found in the bibliography depending on numerous intrinsic and extrinsic soil factors. These factors will determine preliminary soil microbial community composition, subsequent pos-fire initial colonizers and even post-fire growth media characteristics that microbial community will find to start recolonisation. Fire-induced soil bacterial proliferation is a common pattern found after fire, usually related to pH and C availability increased. But when original soil pH is not altered by fire in acid soils, microbial response can be different and fungal response can be crucial to ecosystem recovery. In this study we have compile data related to high mountain soil from Sierra Nevada National park which was affected by a wildfire in 2006 and data obtained by laboratory heating experiment, trying to elucidate the ecological role of fungi in this fragile ecosystem. On the one hand we can observe fire-induced fungal abundance proliferation estimated by plate count method 8 and 32 months after wildfire and even in a short-term (21 d) after laboratory heating at 300 °C. Six years after fire, fungal abundance was similar between samples collected in burnt and unburnt-control area but we found higher proportion of species capable to degrade PAHs (lacase activity) in burnt soil than I the unburnt one. This finding evidences the crucial role of fungal enzymatic capacities to detoxify burnt soils when fire-induced recalcitrant and even toxic carbon compounds could be partially limiting total ecosystem recovery.

  17. Analysis of Post-Fire Vegetation Recovery in the Mediterranean Basin using MODIS Derived Vegetation Indices

    NASA Astrophysics Data System (ADS)

    Hawtree, Daniel; San Miguel, Jesus; Sedano, Fernando; Kempeneers, Pieter

    2010-05-01

    The Mediterranean basin region is highly susceptible to wildfire, with approximately 60,000 individual fires and half a million ha of natural vegetation burnt per year. Of particular concern in this region is the impact of repeated wildfires on the ability of natural lands to return to a pre-fire state, and of the possibility of desertification of semi-arid areas. Given these concerns, understanding the temporal patterns of vegetation recovery is important for the management of environmental resources in the region. A valuable tool for evaluating these recovery patterns are vegetation indices derived from remote sensing data. Previous research on post-fire vegetation recovery conducted in this region has found significant variability in recovery times across different study sites. It is unclear what the primary variables are affecting the differences in the rates of recovery, and if any geographic patterns of behavior exist across the Mediterranean basin. This research has primarily been conducted using indices derived from Landsat imagery. However, no extensive analysis of vegetation regeneration for large regions has been published, and assessment of vegetation recovery on the basis of medium-spatial resolution imagery such as that of MODIS has not yet been analyzed. This study examines the temporal pattern of vegetation recovery in a number of fire sites in the Mediterranean basin, using data derived from MODIS 16 -day composite vegetation indices. The intent is to develop a more complete picture of the temporal sequence of vegetation recovery, and to evaluate what additional factors impact variations in the recovery sequence. In addition, this study evaluates the utility of using MODIS derived vegetation indices for regeneration studies, and compares the findings to earlier studies which rely on Landsat data. Wildfires occurring between the years 2000 and 2004 were considered as potential study sites for this research. Using the EFFIS dataset, all wildfires

  18. Evaluation of post fire changes in soil properties and influence on the hydrological and erosive dynamics in a Mediterranean watershed

    NASA Astrophysics Data System (ADS)

    Sanz, Inés; Aguilar, Cristina; Millares, Agustín

    2013-04-01

    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

  19. Quantifying Fire's Impacts on Total and Pyrogenic Carbon Stocks in Mixed-Conifer Forests: Results from Pre- and Post-Fire Measurements in Active Wildfire Incidents

    NASA Astrophysics Data System (ADS)

    Miesel, J. R.; Reiner, A. L.; Ewell, C. M.; Sanderman, J.; Maestrini, B.; Adkins, J.

    2016-12-01

    Widespread US fire suppression policy has contributed to an accumulation of vegetation in many western forests relative to historic conditions, and these changes can exacerbate wildfire severity and carbon (C) emissions. Serious concern exists about positive feedbacks between wildfire emissions and global climate; however, fires not only release C from terrestrial to atmospheric pools, they also create "black" or pyrogenic C (PyC) which contributes to longer-term C stability. Our objective was to quantify wildfire impacts on aboveground and belowground total C and PyC stocks in California mixed-conifer forests. We worked with incident management teams to access five active wildfires to establish and measure plots within days before and after fire. We measured pre- and post-fire aboveground forest structure and woody fuels to calculate aboveground biomass, biomass C, and PyC, and we collected pre- and post-fire forest floor and 0-5 cm mineral soil samples to measure belowground C and PyC stocks. Our preliminary results show that fire had minimal impact on the number of trees per hectare, whereas C losses from the tree layer occurred via consumption of foliage, and PyC gain occurred in tree bark. Fire released 54% to 100% of surface fuel C. In the forest floor layer, we observed 33 to 100% C loss, whereas changes in PyC stocks ranged from 100% loss to 186% gain relative to pre-fire samples. In general, fire had minimal to no impact on 0-5 cm mineral soil C. We will present relationships between total C, PyC and post-fire C and N dynamics in one of the five wildfire sites. Our data are unique because they represent nearly immediate pre- and post-fire measurements in major wildfires in a widespread western U.S. forest type. This research advances understanding of the role of fire on forest C fluxes and C sequestration potential as PyC.

  20. Quantifying soil burn severity for hydrologic modeling to assess post-fire effects on sediment delivery

    NASA Astrophysics Data System (ADS)

    Dobre, Mariana; Brooks, Erin; Lew, Roger; Kolden, Crystal; Quinn, Dylan; Elliot, William; Robichaud, Pete

    2017-04-01

    Soil erosion is a secondary fire effect with great implications for many ecosystem resources. Depending on the burn severity, topography, and the weather immediately after the fire, soil erosion can impact municipal water supplies, degrade water quality, and reduce reservoirs' storage capacity. Scientists and managers use field and remotely sensed data to quickly assess post-fire burn severity in ecologically-sensitive areas. From these assessments, mitigation activities are implemented to minimize post-fire flood and soil erosion and to facilitate post-fire vegetation recovery. Alternatively, land managers can use fire behavior and spread models (e.g. FlamMap, FARSITE, FOFEM, or CONSUME) to identify sensitive areas a priori, and apply strategies such as fuel reduction treatments to proactively minimize the risk of wildfire spread and increased burn severity. There is a growing interest in linking fire behavior and spread models with hydrology-based soil erosion models to provide site-specific assessment of mitigation treatments on post-fire runoff and erosion. The challenge remains, however, that many burn severity mapping and modeling products quantify vegetation loss rather than measuring soil burn severity. Wildfire burn severity is spatially heterogeneous and depends on the pre-fire vegetation cover, fuel load, topography, and weather. Severities also differ depending on the variable of interest (e.g. soil, vegetation). In the United States, Burned Area Reflectance Classification (BARC) maps, derived from Landsat satellite images, are used as an initial burn severity assessment. BARC maps are classified from either a Normalized Burn Ratio (NBR) or differenced Normalized Burned Ratio (dNBR) scene into four classes (Unburned, Low, Moderate, and High severity). The development of soil burn severity maps requires further manual field validation efforts to transform the BARC maps into a product more applicable for post-fire soil rehabilitation activities

  1. Post-fire ecohydrological conditions at peatland margins in different hydrogeological settings of the Boreal Plain

    NASA Astrophysics Data System (ADS)

    Lukenbach, M. C.; Hokanson, K. J.; Devito, K. J.; Kettridge, N.; Petrone, R. M.; Mendoza, C. A.; Granath, G.; Waddington, J. M.

    2017-05-01

    In the Boreal Plain of Canada, the margins of peatland ecosystems that regulate solute and nutrient fluxes between peatlands and adjacent mineral uplands are prone to deep peat burning. Whether post-fire carbon accumulation is able to offset large carbon losses associated with the deep burning at peatland margins is unknown. For this reason, we examined how post-fire hydrological conditions (i.e. water table depth and periodicity, soil tension, and surface moisture content) and depth of burn were associated with moss recolonization at the peatland margins of three sites. We then interpreted these findings using a hydrogeological systems approach, given the importance of groundwater in determining conditions in the soil-plant-atmosphere continuum in peatlands. Peatland margins dominated by local groundwater flow from adjacent peatland middles were characterized by dynamic hydrological conditions that, when coupled with lowered peatland margin surface elevations due to deep burning, produced two common hydrological states: 1) flooding during wet periods and 2) rapid water table declines during dry periods. These dynamic hydrological states were unfavorable to peatland moss recolonization and bryophytes typical of post-fire recovery in mineral uplands became established. In contrast, at a peatland margin where post-fire hydrological conditions were moderated by larger-scale groundwater flow, flooding and rapid water table declines were infrequent and, subsequently, greater peatland-dwelling moss recolonization was observed. We argue that peatland margins poorly connected to larger-scale groundwater flow are not only prone to deep burning but also lags in post-fire moss recovery. Consequently, an associated reduction in post-fire peat accumulation may occur and negatively affect the net carbon sink status and ecohydrological and biogeochemical function of these peatlands.

  2. Rock gabion, rip-rap, and culvert treatments: Successes and failures in post-fire erosion mitigation, Schultz Fire 2010

    Treesearch

    Daniel G. Neary; Karen A. Koestner

    2011-01-01

    Following the Schultz Fire in June of 2010, several erosion mitigation efforts were undertaken to reduce the impacts of post-fire flooding expected during the 2010 monsoon. One treatment consisted of the placement of large rock rip-rap on targeted fill slopes of a high elevation forest road that contains a buried pipeline supplying water to the city of Flagstaff....

  3. Assessment of post forest fire reclamation in Algarve, Portugal

    NASA Astrophysics Data System (ADS)

    Andrade, Rita; Panagopoulos, Thomas; Guerrero, Carlos; Martins, Fernando; Zdruli, Pandi; Ladisa, Gaetano

    2014-05-01

    Fire is a common phenomenon in Mediterranean landscapes and it plays a crucial role in its transformations, making the determination of its impact on the ecosystem essential for land management. During summer of 2012, a wildfire took place in Algarve, Portugal, on an area mainly covered by sclerophyllous vegetation (39.44%, 10080ha), broad-leaved forest (20.80%, 5300ha), agriculture land with significant areas of natural vegetation (17.40%, 4400ha) and transitional woodlands-shrubs (16.17%, 4100ha). The objective of the study was to determine fire severity in order to plan post-fire treatments and to aid vegetation recovery and land reclamation. Satellite imagery was used to estimate burn severity by detecting physical and ecological changes in the landscape caused by fire. Differenced Normalized Burn Ratio (DNBR) was used to measure burn severity with pre and post fire data of four Landsat images acquired in October 2011, February and August 2012 and April 2013. The initial and extended differenced normalized burn ratio (DiNBR and DeNBR) were calculated. The calculated burned area of 24291 ha was 552ha lower than the map data determined with field reports. The 19.5% of that area was burned with high severity, 45% with moderate severity and 28.3% with low severity. Comparing fire severity and regrowth with land use, it is shown in DiNBR that the most severely burned areas were predominantly sclerophyllous vegetation (37.6%) and broad-leaved forests (31.1%). From the DeNRB it was found that the reestablishment of vegetation was slower in mixed forests and higher in sclerophyllous vegetation and in land with significant areas of natural vegetation. Faster recovery was calculated for the land uses of sclerophyllous vegetation (46.7%) and significant regrowth in areas of natural vegetation and lands occupied by agriculture (25.4%). Next steps of the study are field validation and crossing with erosion risk maps before to take land reclamation decisions.

  4. Validation of a probabilistic post-fire erosion model

    Treesearch

    Pete Robichaud; William J. Elliot; Sarah A. Lewis; Mary Ellen Miller

    2016-01-01

    Post-fire increases of runoff and erosion often occur and land managers need tools to be able to project the increased risk. The Erosion Risk Management Tool (ERMiT) uses the Water Erosion Prediction Project (WEPP) model as the underlying processor. ERMiT predicts the probability of a given amount of hillslope sediment delivery from a single rainfall or...

  5. Emergency assessment of post-fire debris-flow hazards for the 2013 Powerhouse fire, southern California

    USGS Publications Warehouse

    Staley, Dennis M.; Smoczyk, Gregory M.; Reeves, Ryan R.

    2013-01-01

    Wildfire dramatically alters the hydrologic response of a watershed such that even modest rainstorms can produce dangerous flash floods and debris flows. Existing empirical models were used to predict the probability and magnitude of debris-flow occurrence in response to a 10-year recurrence interval rainstorm for the 2013 Powerhouse fire near Lancaster, California. Overall, the models predict a relatively low probability for debris-flow occurrence in response to the design storm. However, volumetric predictions suggest that debris flows that occur may entrain a significant volume of material, with 44 of the 73 basins identified as having potential debris-flow volumes between 10,000 and 100,000 cubic meters. These results suggest that even though the likelihood of debris flow is relatively low, the consequences of post-fire debris-flow initiation within the burn area may be significant for downstream populations, infrastructure, and wildlife and water resources. Given these findings, we recommend that residents, emergency managers, and public works departments pay close attention to weather forecasts and National-Weather-Service-issued Debris Flow and Flash Flood Outlooks, Watches, and Warnings and that residents adhere to any evacuation orders.

  6. Effect of post-fire salvage logging treatments on micobiological properties of two different soils in the Povince of Alicante.

    NASA Astrophysics Data System (ADS)

    Arcenegui, Victoria

    2017-04-01

    It is well known that the natural wildfire regime in Mediterranean forests is greatly disturbed by human activities. Fire can induce temporal or permanent changes in the soil (see Certini, 2005) and can retard or compromise the recovery of the ecosystem afterwards. Changes in soil properties and the impact on soil functions depend mainly on the severity of the fires (Neary et al., 1999) and type of soil and weather during and after burning (Robichaud & Hungerford, 2000). Post-fire management can have an additional impact on the ecosystem; in some cases, even more severe than the fire. Post-fire salvage logging treatments are very frequently but its ecological impact is uncertain. Mainly because there are so many variables at play. A research has been done in "Sierra de Mariola Natural Park" in Alcoi (M) and ''Cabo de San Antonio'' in Javea (J), both in the Province of Alicante (E Spain). A big forest fire (>500 has) occurred in July 2012 and in September 2014 respectively. After fire, salvage logging (SL) treatment were done. In the first area (M), with a soil classified as Typic Xerorthent, extraction of the burned wood using heavy machinery was applied. In contrast, in the second area (J), a Rhodoxeralf soil, not heavy machinery was used. Plots for monitoring this effect were installed in both areas and in a similar nearby area where no treatment was done, and then used as control (C) for comparison. Soil samplings were done immediately after treatment and 4 years and two years in M site and J site respectively. We examined the effect of salvage logging on basal soil respiration (BSR), and microbial biomass carbon (Cmic). Our results showed that in site M four years after the treatment, the plots without treatment showed a much better improvement for the properties monitored. And not differences were found in site J after two years of monitoring. The impact of salvage logging was different depending on the soil type and the way to do the treatment.

  7. Advancements in Hydrology and Erosion Process Understanding and Post-Fire Hydrologic and Erosion Model Development for Semi-Arid Landscapes

    NASA Astrophysics Data System (ADS)

    Williams, C. Jason; Pierson, Frederick B.; Al-Hamdan, Osama Z.; Robichaud, Peter R.; Nearing, Mark A.; Hernandez, Mariano; Weltz, Mark A.; Spaeth, Kenneth E.; Goodrich, David C.

    2017-04-01

    Fire activity continues to increase in semi-arid regions around the globe. Private and governmental land management entities are challenged with predicting and mitigating post-fire hydrologic and erosion responses on these landscapes. For more than a decade, a team of scientists with the US Department of Agriculture has collaborated on extensive post-fire hydrologic field research and the application of field research to development of post-fire hydrology and erosion predictive technologies. Experiments funded through this research investigated the impacts of fire on vegetation and soils and the effects of these fire-induced changes on infiltration, runoff generation, erodibility, and soil erosion processes. The distribution of study sites spans diverse topography across grassland, shrubland, and woodland landscapes throughout the western United States. Knowledge gleaned from the extensive field experiments was applied to develop and enhance physically-based models for hillslope- to watershed-scale runoff and erosion prediction. Our field research and subsequent data syntheses have identified key knowledge gaps and challenges regarding post-fire hydrology and erosion modeling. Our presentation details some consistent trends across a diverse domain and varying landscape conditions based on our extensive field campaigns. We demonstrate how field data have advanced our understanding of post-fire hydrology and erosion for semi-arid landscapes and highlight remaining key knowledge gaps. Lastly, we briefly show how our well-replicated experimental methodologies have contributed to advancements in hydrologic and erosion model development for the post-fire environment.

  8. Post-fire land management: Comparative effects of different strategies on hillslope sediment yield

    NASA Astrophysics Data System (ADS)

    Cole, R.; Bladon, K. D.; Wagenbrenner, J.; Coe, D. B. R.

    2017-12-01

    High-severity wildfire can increase erosion on burned, forested hillslopes. Salvage logging is a post-fire land management practice to extract economic value from burned landscapes, reduce fuel loads, and improve forest safety. Few studies assess the impact of post-fire salvage logging or alternative land management approaches on erosion in forested landscapes, especially in California. In September 2015, the Valley Fire burned approximately 31,366 ha of forested land and wildland-urban interface in the California's Northern Coast Range, including most of Boggs Mountain Demonstration State Forest. The primary objective of our study is to quantify erosion rates at the plot scale ( 75 m2) for different post-fire land management practices, including mechanical logging and subsoiling (or ripping) after logging. We measured sediment yields using sediment fences in four sets of replicated plots. We also estimated ground cover in each plot using three randomly positioned 1-meter quadrats. We are also measuring rainfall near each plot to understand hydrologic factors that influence erosion. Preliminary results indicate that burned, unlogged reference plots yielded the most sediment over the winter rainy season (3.3 kg m-2). Sediment yields of burned and logged (0.9 kg m-2), and burned, logged, and ripped (0.7 kg m-2), were substantially lower. Burned and unlogged reference plots had the least ground cover (49%), while ground cover was higher and more similar between logged (65%) and logged and ripped (72%) plots. These initial results contrast with previous studies in which the effect of post-fire salvage logging ranged from no measured impact to increased sediment yield related to salvage logging.

  9. Characterization of post-fire surface cover, soils, and burn severity at the Cerro Grande Fire, New Mexico, using hyperspectral and multispectral remote sensing

    USGS Publications Warehouse

    Kokaly, R.F.; Rockwell, B.W.; Haire, S.L.; King, T.V.V.

    2007-01-01

    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

  10. Shrub removal in reforested post-fire areas increases native plant species richness

    Treesearch

    Gabrielle N. Bohlman; Malcolm North; Hugh D. Safford

    2016-01-01

    Large, high severity fires are becoming more prevalent in Sierra Nevada mixed-conifer forests, largely due to heavy fuel loading and forest densification caused by past and current management practices. In post-fire areas distant from seed trees, conifers are often planted to re-establish a forest and to prevent a potential type-conversion to shrub fields. Typical...

  11. Leaf and shoot water content and leaf dry matter content of Mediterranean woody species with different post-fire regenerative strategies.

    PubMed

    Saura-Mas, S; Lloret, F

    2007-03-01

    Post-fire regeneration is a key process in Mediterranean shrubland dynamics, strongly determining the functional properties of the community. In this study, a test is carried out to determine whether there is co-variation between species regenerative types and functional attributes related to water use. An analysis was made of the seasonal variations in leaf relative water content (RWC), leaf dry matter content (LDMC), leaf moisture (LM) and live fine fuel moisture (LFFM) in 30 woody species of a coastal shrubland, with different post-fire regenerative strategies (seeding, resprouting or both). RWC results suggest that the studied resprouters have more efficient mechanisms to reduce water losses and maintain water supply between seasons. In contrast, seeders are more drought tolerant. LDMC is higher in resprouters over the course of the year, suggesting a more efficient conservation of nutrients. The weight of the phylogenetic constraint to understand differences between regenerative strategies tends to be important for LDMC, while it is not the case for variables such as RWC. Groups of species with different post-fire regenerative strategies (seeders and resprouters) have different functional traits related to water use. In addition to the role of phylogenetical constraints, these differences are also likely to be related to the respective life history characteristics. Therefore, the presence and abundance of species with different post-fire regenerative responses influence the functional properties of the communities.

  12. Snag longevity and surface fuel accumulation following post-fire logging in a ponderosa pine dominated forest

    Treesearch

    Martin W. Ritchie; Eric E. Knapp; Carl N. Skinner

    2013-01-01

    In a study of post-fire logging effects over an 8 year period at Blacks Mountain Experimental Forest, salvage logging was conducted at varying levels of intensity after a 2002 wildfire event. In a designed experiment, harvest prescriptions with snag retention levels ranging from 0% to 100% in 15 experimental units were installed. Observations of standing snags and...

  13. First report of the post-fire morel, Morchella exuberans, in eastern North America

    USDA-ARS?s Scientific Manuscript database

    Reports of true morels (Morchella) fruiting on conifer burn sites are common in western North America where five different fire-adapted species of black morels (Elata Clade) have been documented based on multilocus phylogenetic analyses. Fruiting of post-fire morels in eastern North America, by comp...

  14. Southwestern Oregon's Biscuit Fire: An Analysis of Forest Resources, Fire Severity, and Fire Hazard

    Treesearch

    David L. Azuma; Glenn A. Christensen

    2005-01-01

    This study compares pre-fire field inventory data (collected from 1993 to 1997) in relation to post-fire mapped fire severity classes and the Fire and Fuels Extension of the Forest Vegetation Simulator growth and yield model measures of fire hazard for the portion of the Siskiyou National Forest in the 2002 Biscuit fire perimeter of southwestern Oregon. Post-fire...

  15. Analyzing Hydro-Geomorphic Responses in Post-Fire Stream Channels with Terrestrial LiDAR

    NASA Astrophysics Data System (ADS)

    Nourbakhshbeidokhti, S.; Kinoshita, A. M.; Chin, A.

    2015-12-01

    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.

  16. Intensification of freeze-thaw cycles in the soil on post-fire alpine slopes of Mount Shirouma-dake, northern Japanese Alps central Japan

    NASA Astrophysics Data System (ADS)

    Sasaki, A.; Suzuki, K.

    2016-12-01

    This is the continuous study to clarify the geo-environmental changes on the post-fire alpine slopes of Mount Shirouma-dake in the Northern Japanese Alps. The fire occurred at May 9, 2009 on the alpine slopes of Mount Shirouma-dake, and the fire spread to the Pinus pumila communities and grasslands. Although the grass had a little damage by the fire, the P. pumila received nearly impact of the fire. In the P. pumila communities where the leaf burnt, forest floor is exposed and become easy to be affected by atmospheric condition such as rain, wind, snow, and etc. First, we observed condition of the micro-landforms on post-fire slopes repeatedly for seventh years after the fire. As the results of the observation, it is clear that remarkable changes of these micro-landforms have not occurred but some litters on the forest-floor in the fired P. pumila communities are flushed out to surroundings. The litter layer on the forest-floor in the fired P. pumila communities were 3-4 cm thick in August of 2011, but it became 0.5 cm thick in September of 2014. The P. pumila communities established on the slopes consists of angular and sub-angular gravel with openwork texture, which are covered by thin soil layer. On July of 2016, the litter layer almost entirely flushed out and surface of soil layer is exposed to atmosphere. In addition, we observe the ground temperature and soil moisture, under the fired P. pumila communities and the no fired P. pumila communities since October 2009, to find influence of the fire. The ground temperature sensors were installed into at 1 cm, 10 cm, and 40 cm depth. The soil moisture sensors were installed into at 1 cm and 10 cm depth. The 1 cm depth of the soil on the post-fire slopes, several times of diurnal freeze-thaw cycles occurred on October and November since 2011, but it had not occurred in 2009 and 2010. In particular, more than 20 times of diurnal freeze-thaw cycles occurred on freezing period of 2014. The diurnal freeze-thaw cycles

  17. Assessing impacts of fire and post-fire on runoff and erosion from rangelands mitigation

    Treesearch

    Frederick B. Pierson; C. Jason Williams; Pete Robichaud

    2015-01-01

    To provide an overview of the immediate and short-term hydrologic impacts of fire on infiltration, runoff, and erosion by water, and of the effectiveness of various mitigation treatments in the reduction of runoff and erosion in the years following the fire.

  18. Improving satellite-based post-fire evapotranspiration estimates in semi-arid regions

    NASA Astrophysics Data System (ADS)

    Poon, P.; Kinoshita, A. M.

    2017-12-01

    Climate change and anthropogenic factors contribute to the increased frequency, duration, and size of wildfires, which can alter ecosystem and hydrological processes. The loss of vegetation canopy and ground cover reduces interception and alters evapotranspiration (ET) dynamics in riparian areas, which can impact rainfall-runoff partitioning. Previous research evaluated the spatial and temporal trends of ET based on burn severity and observed an annual decrease of 120 mm on average for three years after fire. Building upon these results, this research focuses on the Coyote Fire in San Diego, California (USA), which burned a total of 76 km2 in 2003 to calibrate and improve satellite-based ET estimates in semi-arid regions affected by wildfire. The current work utilizes satellite-based products and techniques such as the Google Earth Engine Application programming interface (API). Various ET models (ie. Operational Simplified Surface Energy Balance Model (SSEBop)) are compared to the latent heat flux from two AmeriFlux eddy covariance towers, Sky Oaks Young (US-SO3), and Old Stand (US-SO2), from 2000 - 2015. The Old Stand tower has a low burn severity and the Young Stand tower has a moderate to high burn severity. Both towers are used to validate spatial ET estimates. Furthermore, variables and indices, such as Enhanced Vegetation Index (EVI), Normalized Difference Moisture Index (NDMI), and the Normalized Burn Ratio (NBR) are utilized to evaluate satellite-based ET through a multivariate statistical analysis at both sites. This point-scale study will able to improve ET estimates in spatially diverse regions. Results from this research will contribute to the development of a post-wildfire ET model for semi-arid regions. Accurate estimates of post-fire ET will provide a better representation of vegetation and hydrologic recovery, which can be used to improve hydrologic models and predictions.

  19. Effects of fire intensity on vital rates of an endemic herb of the Florida keys, USA

    USGS Publications Warehouse

    Liu, H.; Menges, E.S.; Snyder, J.R.; Koptur, S.; Ross, M.S.

    2005-01-01

    Fire intensity is one of the important components of a fire regime. However, relatively few studies have linked fire intensity with post-fire population vital rates. In this study, we explored the effects of fire intensity on population vital rates of Chamaecrista keyensis Pennell (Fabaceae) up to two years post-fire. C. keyensis is an endemic understory plant of pine rockland, a fire-dependent ecosystem of the Lower Florida Keys. We measured one fire intensity indicator, fire temperature reached by steel plates on the ground, during three prescribed fires at different sites. We followed marked individuals up to two years post-fire to derive annual survival, annual growth rate, percentage of fruiting plants, mean number of fruits per reproductive plant, and number of seedlings per census plot (1 m2) of C. keyensis. We found fire intensity had significant effects on reproduction in the first year post-fire only. More specifically, mean number of fruits and percentage of fruiting plants increased as fire intensity increased. Results from this study suggest that extremely low fire intensity caused by very short fire return intervals (e.g., less than three years) may not provide sufficient stimulation to reproduction to achieve the best post-fire recovery for C. keyensis.

  20. Rates of post-fire vegetation recovery and fuel accumulation as a function of burn severity and time-since-burn in four western U.S. ecosystems

    USDA-ARS?s Scientific Manuscript database

    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...

  1. Fuel loads, fire regimes, and post-fire fuel dynamics in Florida Keys pine forests

    USGS Publications Warehouse

    Sah, J.P.; Ross, M.S.; Snyder, J.R.; Koptur, S.; Cooley, H.C.

    2006-01-01

    In forests, the effects of different life forms on fire behavior may vary depending on their contributions to total fuel loads. We examined the distribution of fuel components before fire, their effects on fire behavior, and the effects of fire on subsequent fuel recovery in pine forests within the National Key Deer Refuge in the Florida Keys. We conducted a burning experiment in six blocks, within each of which we assigned 1-ha plots to three treatments: control, summer, and winter burn. Owing to logistical constraints, we burned only 11 plots, three in winter and eight in summer, over a 4-year period from 1998 to 2001. We used path analysis to model the effects of fuel type and char height, an indicator of fire intensity, on fuel consumption. Fire intensity increased with surface fuel loads, but was negatively related to the quantity of hardwood shrub fuels, probably because these fuels are associated with a moist microenvironment within hardwood patches, and therefore tend to resist fire. Winter fires were milder than summer fires, and were less effective at inhibiting shrub encroachment. A mixed seasonal approach is suggested for fire management, with burns applied opportunistically under a range of winter and summer conditions, but more frequently than that prevalent in the recent past. ?? IAWF 2006.

  2. Remote sensing of fire severity: linking post-fire reflectance data with physiological responses in two western conifer species

    NASA Astrophysics Data System (ADS)

    Sparks, A. M.; Smith, A. M.; Kolden, C.; Apostol, K. G.; Boschetti, L.

    2014-12-01

    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.

  3. Field guide for mapping post-fire soil burn severity

    Treesearch

    Annette Parson; Peter R. Robichaud; Sarah A. Lewis; Carolyn Napper; Jess T. Clark

    2010-01-01

    Following wildfires in the United States, the U.S. Department of Agriculture and U.S. Department of the Interior mobilize Burned Area Emergency Response (BAER) teams to assess immediate post-fire watershed conditions. BAER teams must determine threats from flooding, soil erosion, and instability. Developing a postfire soil burn severity map is an important first step...

  4. Fire Danger Rating: The next 20 Years

    Treesearch

    John E. Deeming

    1987-01-01

    For the next 10 years, few changes will be made to the fire-danger rating system. During that time, the focus will be on the automation of weather observing systems and the streamlining of the computation and display of ratings. The time horizon for projecting fire danger will be pushed to 30 days by the late 1990's. A close alignment of the fire-danger rating...

  5. Influence of climate and environment on post-fire recovery of mountain big sagebrush

    Treesearch

    Zachary J. Nelson; Peter J. Weisberg; Stanley G. Kitchen

    2014-01-01

    In arid and semi-arid landscapes around the world, wildfire plays a key role in maintaining species diversity. Dominant plant associations may depend upon particular fire regime characteristics for their persistence. Mountain shrub communities in high-elevation landscapes of the Intermountain West, USA, are strongly influenced by the post-fire recovery dynamics of the...

  6. Quantifying Post-Fire Aeolian Sediment Transport Using Rare Earth Element Tracers.

    NASA Astrophysics Data System (ADS)

    Dukes, D.; Ravi, S.; Grandstaff, D. E.; Gonzales, H. B.; Li, J. J.; Sankey, J. B.; Wang, G.; Van Pelt, R. S.

    2016-12-01

    Grasslands and rangelands in arid and semi-arid regions of the world, which provide fundamental ecosystem services, are undergoing rapid increases in fire activity and are highly susceptible to post-fire accelerated soil erosion by wind. A quantitative assessment that integrates fire-wind erosion feedbacks is therefore critically needed in understanding vegetation change, soil biogeochemical cycling, air quality, and landscape evolution. We investigated the applicability of a novel tracer technique - the use of rare earth element (REE) tracers - to quantify soil erosion by wind and to identify sources and sinks of wind-blown sediments in both a burned and unburned shrub-grass transition zone within the Chihuahuan desert (New Mexico, USA). At the beginning of the windy season, March 2016, silt and sand sized particles in shrub, grass, and bare microsites were each tagged with a unique REE oxide, Ho, Eu, and Yb respectively. Samples were then taken directly after application prior to a prescribed fire and again at the end of the windy season in June 2016. All REE tracers showed signs of depletion and mixing, with the depletion in the burned site up to 20% greater than the unburned. REE concentration comparisons between the burned and unburned plots reveal a shift in the source and sink dynamics of sediment post fire. In unburned plots, changes in microsite REE concentrations indicate that sediment moved from the bare to vegetated microsites, whereas the opposite occurred in burned plots. However, burned plot grass microsites acted as a sink for sediment from shrub microsites, whereas unburned plot grass microsites exhibited no enrichment from shrub microsite-sourced sediment. Though fires are known to immediately increase aeolian sediment transport, accompanying changes in the sources and sinks of wind borne sediment may influence biogeochemical cycling and vegetation shifts possibly providing a feedback mechanism for land degradation in dryland ecosystems.

  7. Effects of post-fire wood management strategies on vegetation recovery and land surface temperature (LST) estimated from Landsat images

    NASA Astrophysics Data System (ADS)

    Vlassova, Lidia; Pérez-Cabello, Fernando

    2016-02-01

    The study contributes remote sensing data to the discussion about effects of post-fire wood management strategies on forest regeneration. Land surface temperature (LST) and Normalized Differenced Vegetation Index (NDVI), estimated from Landsat-8 images are used as indicators of Pinus halepensis ecosystem recovery after 2008 fire in areas of three post-fire treatments: (1) salvage logging with wood extraction from the site on skidders in suspended position (SL); (2) snag shredding in situ leaving wood debris in place (SS) performed two years after the event; and (3) non-intervention control areas (CL) where all snags were left standing. Six years after the fire NDVI values ∼0.5 estimated from satellite images and field radiometry indicate considerable vegetation recovery due to efficient regeneration traits developed by the dominant plant species. However, two years after management activities in part of the burnt area, the effect of SL and SS on ecosystem recovery is observed in terms of both LST and NDVI. Statistically significant differences are detected between the intervened areas (SL and SS) and control areas of non-intervention (CL); no difference is registered between zones of different intervention types (SL and SS). CL areas are on average 1 °C cooler and 10% greener than those corresponding to either SL or SS, because of the beneficial effects of burnt wood residuals, which favor forest recovery through (i) enhanced nutrient cycling in soils, (ii) avoidance of soil surface disturbance and mechanical damage of seedlings typical to the managed areas, and (iii) ameliorated microclimate. The results of the study show that in fire-resilient ecosystems, such as P. halepensis forests, NDVI is higher and LST is lower in areas with no management intervention, being an indication of more favorable conditions for vegetation regeneration.

  8. Polyacrylamide application versus forest residue mulching for reducing post-fire runoff and soil erosion.

    PubMed

    Prats, Sergio Alegre; Martins, Martinho António Dos Santos; Malvar, Maruxa Cortizo; Ben-Hur, Meni; Keizer, Jan Jacob

    2014-01-15

    For several years now, forest fires have been known to increase overland flow and soil erosion. However, mitigation of these effects has been little studied, especially outside the USA. This study aimed to quantify the effectiveness of two so-called emergency treatments to reduce post-fire runoff and soil losses at the microplot scale in a eucalyptus plantation in north-central Portugal. The treatments involved the application of chopped eucalyptus bark mulch at a rate of 10-12 Mg ha(-1), and surface application of a dry, granular, anionic polyacrylamide (PAM) at a rate of 50 kg ha(-1). During the first year after a wildfire in 2010, 1419 mm of rainfall produced, on average, 785 mm of overland flow in the untreated plots and 8.4 Mg ha(-1) of soil losses. Mulching reduced these two figures significantly, by an average 52 and 93%, respectively. In contrast, the PAM-treated plots did not differ from the control plots, despite slightly lower runoff but higher soil erosion figures. When compared to the control plots, mean key factors for runoff and soil erosion were different in the case of the mulched but not the PAM plots. Notably, the plots on the lower half of the slope registered bigger runoff and erosion figures than those on the upper half of the slope. This could be explained by differences in fire intensity and, ultimately, in pre-fire standing biomass. © 2013 Elsevier B.V. All rights reserved.

  9. Impact of Fire on Streamflow in Southern California Watersheds

    NASA Astrophysics Data System (ADS)

    Bart, R. R.; Hope, A. S.

    2007-12-01

    Post-fire streamflow dynamics in Southern California have primarily been studied using small watershed experiments. These studies have concluded that increases in streamflow are a consequence of an increase in soil hydrophobicity, along with a decrease in transpiration rates associated with less vegetation. Extrapolation of the results from these studies to large watersheds (>50 km2) has been limited because large watersheds may not burn completely and other processes may emerge at these scales. In this study, six paired watersheds were used to test the hypothesis that there is an increase in streamflow following fire in large California watersheds (54-632 km2). The percentage of area burned in these watersheds ranged from 23 to 100%. The effects of fires on streamflow were examined at annual, seasonal, and monthly time-steps for the five years following fire. In addition, this study attempted to address fundamental regression assumptions that are commonly ignored, and create uncertainty bounds for evaluating the changes in streamflow before and after fire. Results of this experiment indicate that differences in pre and post-fire streamflows, at all time scales and in all the test catchments, were generally within the 95% uncertainty bounds of the regression equation. It is uncertain whether the apparent lack of significant difference between the pre and post-fire streamflow reflects no actual change in streamflow or is a consequence of the errors and uncertainties in the streamflow data. Furthermore, persistent drought in the years following fire made it challenging to interpret differences in pre and post-fire flows using the paired watershed methodology. The effects of hydrophobicity on post-fire streamflow may have been reduced by a limited number of storm flow events during these drought years. Under these dry conditions, soil moisture was the dominant control over transpirational losses, minimizing the effects of a reduction in vegetation cover. These results

  10. Mapping and exploring variation in post-fire vegetation recovery following mixed severity wildfire using airborne LiDAR.

    PubMed

    Gordon, Christopher E; Price, Owen F; Tasker, Elizabeth M

    2017-07-01

    There is a public perception that large high-severity wildfires decrease biodiversity and increase fire hazard by homogenizing vegetation composition and increasing the cover of mid-story vegetation. But a growing literature suggests that vegetation responses are nuanced. LiDAR technology provides a promising remote sensing tool to test hypotheses about post-fire vegetation regrowth because vegetation cover can be quantified within different height strata at fine scales over large areas. We assess the usefulness of airborne LiDAR data for measuring post-fire mid-story vegetation regrowth over a range of spatial resolutions (10 × 10 m, 30 × 30 m, 50 × 50 m, 100 × 100 m cell size) and investigate the effect of fire severity on regrowth amount and spatial pattern following a mixed severity wildfire in Warrumbungle National Park, Australia. We predicted that recovery would be more vigorous in areas of high fire severity, because park managers observed dense post-fire regrowth in these areas. Moderate to strong positive associations were observed between LiDAR and field surveys of mid-story vegetation cover between 0.5-3.0 m. Thus our LiDAR survey was an apt representation of on-ground vegetation cover. LiDAR-derived mid-story vegetation cover was 22-40% lower in areas of low and moderate than high fire severity. Linear mixed-effects models showed that fire severity was among the strongest biophysical predictors of mid-story vegetation cover irrespective of spatial resolution. However much of the variance associated with these models was unexplained, presumably because soil seed banks varied at finer scales than our LiDAR maps. Dense patches of mid-story vegetation regrowth were small (median size 0.01 ha) and evenly distributed between areas of low, moderate and high fire severity, demonstrating that high-severity fires do not homogenize vegetation cover. Our results are relevant for ecosystem conservation and fire management because they: indicate

  11. How well does the Post-fire Erosion Risk Management Tool (ERMiT) really work?

    NASA Astrophysics Data System (ADS)

    Robichaud, Peter; Elliot, William; Lewis, Sarah; Miller, Mary Ellen

    2016-04-01

    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.

  12. Measuring and Modeling the Effects of Alternate Post-Fire Successional Trajectories on Boreal Forest Carbon Dynamics

    NASA Astrophysics Data System (ADS)

    Loranty, M. M.; Goetz, S. J.; Mack, M. C.; Alexander, H. D.; Beck, P. S.

    2011-12-01

    High latitude ecosystems are experiencing amplified climate warming, and recent evidence suggests concurrent intensification of fire disturbance regimes. In central Alaskan boreal forests, severe burns consume more of the soil organic layer, resulting in increased establishment of deciduous seedlings and altered post-fire stand composition with increased deciduous dominance. Quantifying differences in ecosystem carbon (C) dynamics between forest successional trajectories in response to burn severity is essential for understanding potential changes in regional or global feedbacks between boreal forests and climate. We used the Biome BioGeochemical Cycling model (Biome-BGC) to quantify differences in C stocks and fluxes associated with alternate post-fire successional trajectories related to fire severity. A version of Biome-BGC that allows alternate competing vegetation types was calibrated against a series of aboveground biomass observations from chronosequences of stands with differing post-fire successional trajectories characterized by the proportion of deciduous biomass. The model was able to reproduce observed patterns of biomass accumulation after fire, with stands dominated by deciduous species sequestering more C at a faster rate than stands dominated by conifers. Modeled C fluxes suggest that stands dominated by deciduous species are a stronger sink of atmospheric C soon after disturbance than coniferous stands. These results agree with the few available C flux observations. We use a historic database in conjunction with a map of deciduous canopy cover to explore the consequences of ongoing and potential future changes in the fire regime on central Alaskan C balance.

  13. Effects of fire and post-fire salvage logging on avian communities in conifer-dominated forests of the western United States

    USGS Publications Warehouse

    Kotliar, N.B.; Hejl, S.J.; Hutto, R.L.; Saab, V.; Melcher, Cynthia; McFadzen, M.E.; George, T.L.; Dobkin, D.S.

    2002-01-01

    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 postfire 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 postfire 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 tire 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, postfire 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

  14. Does browsing reduce shrub survival and vigor following summer fires?

    NASA Astrophysics Data System (ADS)

    Fulbright, Timothy E.; Dacy, Emily C.; Drawe, D. Lynn

    2011-01-01

    Periodic fire is widely hypothesized to limit woody plant encroachment in semiarid grasslands. In southern Texas, however, most of the woody plants that have invaded grasslands during the past two centuries are resistant to fire. We hypothesized that browsing by Odocoileus virginianus increases mortality of palatable shrubs and reduces vigor of shrubs following fire. We randomly selected ten pairs of each of three shrub species -Condalia hookeri, Acacia farnesiana, and Celtis ehrenbergiana - in each of three locations before prescribed burns during summer 2001. Following burns, we used a wire fence to protect one shrub of each pair from browsing. We estimated intensity of O. virginianus browsing and number and height of sprouts 4, 12, 20, 30, 38, and 47 weeks post-fire. We determined shrub height, survival, and biomass one year post-fire. Averaged across species, browsing intensity on unfenced shrubs was greater (LS Means, P < 0.05) than on fenced shrubs on all sampling dates except four and 30 weeks post-fire. Mortality of unfenced (11 ± 9%) (mean ± SE) and fenced (12 ± 7%, n = 9) shrubs was similar (P = 0.674) one year post-fire, averaged across shrub species. Number of sprouts, sprout height, total plant height, and biomass of protected and browsed plants were similar (P > 0.05) one year post-burn. Browsing by O. virginianus at the intensity in our study does not increase mortality or reduce vigor of C. hookeri, A. farnesiana, and Condalia ehrenbergiana producing new growth following destruction of aboveground tissues by a single fire compared to shrubs that are not browsed following fire.

  15. Effects of post-fire logging on forest surface air temperatures in the Siskiyou Mountains, Oregon, USA

    Treesearch

    Joseph B. Fontaine; Daniel C. Donato; John L. Campbell; Jonathan G. Martin; Beverley E. Law

    2010-01-01

    Following stand-replacing wildfire, post-fire (salvage) logging of fire-killed trees is a widely implemented management practice in many forest types. A common hypothesis is that removal of fire-killed trees increases surface temperatures due to loss of shade and increased solar radiation, thereby influencing vegetation establishment and possibly stand development. Six...

  16. Post-fire Tree Mortality: Heating Increases Vulnerability to Cavitation in Longleaf Pine Branches

    NASA Astrophysics Data System (ADS)

    Lodge, A.; Kavanagh, K.; Dickinson, M. B.

    2016-12-01

    Tree mortality following wild and prescribed fires is of interest to both researchers and land managers. While some models exist that can predict mortality following fires, process-based models that incorporate physiological mechanisms of mortality are still being developed and improved. Delayed post-fire tree mortality has recently received increased attention, in part due to an increased use of prescribed fire as a restoration and management tool. One hypothesized mechanism of delayed mortality in trees is disruption of water transport in xylem due to exposure to the heat plume of a fire. This heat plume rapidly increases the vapor pressure deficit in the tree canopy, quickly increasing the tension on the water held in the xylem and leaves, potentially leading to cavitation. Cavitated xylem conduits can no longer transport water, eventually leading to tree death. We conducted a laboratory experiment examining whether heating stems increases their vulnerability to cavitation. We placed longleaf pine (Pinus palustris) branches in a water bath at sub-lethal temperatures (<60°C) and applied pressure in a cavitation chamber to simulate a range of xylem tension levels that may occur during fire. Percent loss of conductivity was measured following cavitation induced by various levels of applied pressure. When we compared the resulting vulnerability curves of heated branches to those of branches pressurized at room temperature, we observed increased vulnerability to cavitation in the heated samples especially at lower pressures. P50, or the pressure at which 50% of conductivity has been lost, decreased by 18% on branches heated to approximately 54°C. This suggests that stems heated during fires may be more vulnerable to cavitation, and provides some support for hydraulic disruption as a mechanism for post-fire tree mortality. Continued advancement in understanding of the mechanisms leading to delayed mortality will improve models predicting tree mortality.

  17. Fire investigation

    NASA Astrophysics Data System (ADS)

    Gomberg, A.

    There was considerable progress made on several fronts of fire investigation in the United States in recent years. Progress was made in increasing the quantity of fire investigation and reporting, through efforts to develop the National Fire Incident Reporting System. Improving overall quality of fire investigation is the objective of efforts such as the Fire Investigation Handbook, which was developed and published by the National Bureau of Standards, and the upgrading and expanding of the ""dictionary'' of fire investigation and reporting, the NFPA 901, Uniform Coding for Fire Protection, system. The science of fire investigation as furthered also by new approaches to post fire interviews being developed at the University of Washington, and by in-depth research into factors involved in several large loss fires, including the MGM Grand Hotel in Las Vegas. Finally, the use of special study fire investigations - in-depth investigations concentrating on specific fire problems - is producing new glimpses into the nature of the national fire problem. A brief description of the status of efforts in each of these areas is discussed.

  18. Pre-fire and post-fire surface fuel and cover measurements collected in the southeastern United States for model evaluation and development - RxCADRE 2008, 2011 and 2012

    Treesearch

    Roger D. Ottmar; Andrew T. Hudak; Susan J. Prichard; Clinton S. Wright; Joseph C. Restaino; Maureen C. Kennedy; Robert E. Vihnanek

    2016-01-01

    A lack of independent, quality-assured data prevents scientists from effectively evaluating predictions and uncertainties in fire models used by land managers. This paper presents a summary of pre-fire and post-fire fuel, fuel moisture and surface cover fraction data that can be used for fire model evaluation and development. The data were collected in the...

  19. Rapid Response Tools and Datasets for Post-fire Hydrological Modeling

    NASA Astrophysics Data System (ADS)

    Miller, Mary Ellen; MacDonald, Lee H.; Billmire, Michael; Elliot, William J.; Robichaud, Pete R.

    2016-04-01

    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

  20. A review of logistic regression models used to predict post-fire tree mortality of western North American conifers

    Treesearch

    Travis Woolley; David C. Shaw; Lisa M. Ganio; Stephen Fitzgerald

    2012-01-01

    Logistic regression models used to predict tree mortality are critical to post-fire management, planning prescribed bums and understanding disturbance ecology. We review literature concerning post-fire mortality prediction using logistic regression models for coniferous tree species in the western USA. We include synthesis and review of: methods to develop, evaluate...

  1. Assessing post-fire ground cover in Mediterranean shrublands with field spectrometry and digital photography

    NASA Astrophysics Data System (ADS)

    Montorio Llovería, Raquel; Pérez-Cabello, Fernando; García-Martín, Alberto

    2016-09-01

    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.

  2. Fire in Eastern Hardwood Forests through 14,000 Years

    Treesearch

    Martin A. Spetich; Roger W. Perry; Craig A. Harper; Stacy L. Clark

    2011-01-01

    Fire helped shape the structure and species composition of hardwood forests of the eastern United States over the past 14,000 years. Periodic fires were common in much of this area prior to European settlement, and fire-resilient species proliferated. Early European settlers commonly adopted Native American techniques of applying fire to the landscape. As the demand...

  3. Regional constraints to biological nitrogen fixation in post-fire forest communities

    USGS Publications Warehouse

    Yelenik, Stephanie; Perakis, Steven S.; Hibbs, David

    2013-01-01

    Biological nitrogen fixation (BNF) is a key ecological process that can restore nitrogen (N) lost in wildfire and shape the pace and pattern of post-fire forest recovery. To date, there is limited information on how climate and soil fertility interact to influence different pathways of BNF in early forest succession. We studied asymbiotic (forest floor and soil) and symbiotic (the shrub Ceanothus integerrimus) BNF rates across six sites in the Klamath National Forest, California, USA. We used combined gradient and experimental phosphorus (P) fertilization studies to explore cross-site variation in BNF rates and then related these rates to abiotic and biotic variables. We estimate that our measured BNF rates 22 years after wildfire (6.1–12.1 kg N·ha-1·yr-1) are unlikely to fully replace wildfire N losses. We found that asymbiotic BNF is P limited, although this is not the case for symbiotic BNF in Ceanothus. In contrast, Ceanothus BNF is largely driven by competition from other vegetation: in high-productivity sites with high potential evapotranspiration (Et), shrub biomass is suppressed as tree biomass increases. Because shrub biomass governed cross-site variation in Ceanothus BNF, this competitive interaction led to lower BNF in sites with high productivity and Et. Overall, these results suggest that the effects of nutrients play a larger role in driving asymbiotic than symbiotic fixation across our post-fire sites. However, because symbiotic BNF is 8–90x greater than asymbiotic BNF, it is interspecific plant competition that governs overall BNF inputs in these forests.

  4. Usability and Functional Enhancements to an Online Interface for Predicting Post Fire Erosion (WEPP-PEP)

    NASA Astrophysics Data System (ADS)

    Lew, Roger; Dobre, Mariana; Elliot, William; Robichaud, Pete; Brooks, Erin; Frankenberger, Jim

    2017-04-01

    There is an increased interest in the United States to use soil burn severity maps in watershed-scale hydrologic models to estimate post-fire sediment erosion from burned areas. This information is needed by stakeholders in order to concentrate their pre- or post-fire management efforts in ecologically sensitive areas to decrease the probability of post-fire sediment delivery. But these tools traditionally have been time consuming and difficult to use by managers because input datasets must be obtained and correctly processed for valid results. The Water Erosion Prediction Project (WEPP) has previously been developed as an online and easy-to-use interface to help land managers with running simulations without any knowledge of computer programming or hydrologic modeling. The interface automates the acquisition of DEM, climate, soils, and landcover data, and also automates channel and hillslope delineation for the users. The backend is built with Mapserver, GDAL, PHP, C++, Python while the front end uses OpenLayers, and, of course, JavaScript. The existing WEPP online interface was enhanced to provide better usability to stakeholders in United States (Forest Service, BLM, USDA) as well as to provide enhanced functionality for managing both pre-fire and post-fire treatments. Previously, only site administrators could add burn severity maps. The interface now allows users to create accounts to upload and share FlamMap prediction maps, differenced Normalized Burned Ratio (dNBR), or Burned Area Reflectance Classification (BARC) maps. All maps are loaded into a sortable catalog so users can quickly find their area of interest. Once loaded, the interface has been modified to support running comparisons between baseline condition with "no burn" and with a burn severity classification map. The interface has also been enhanced to allow users to conduct single storm analyses to examine, for example, how much soil loss would result after a 100-year storm. An OpenLayers map

  5. Mixed-severity fire fosters heterogeneous spatial patterns of conifer regeneration in a dry conifer forest

    Treesearch

    Sparkle L. Malone; Paula J. Fornwalt; Mike A. Battaglia; Marin E. Chambers; Jose M. Iniguez; Carolyn H. Sieg

    2018-01-01

    We examined spatial patterns of post-fire regenerating conifers in a Colorado, USA, dry conifer forest 11-12 years following the reintroduction of mixed-severity fire. We mapped and measured all post-fire regenerating conifers, as well as all other post-fire regenerating trees and all residual (i.e., surviving) trees, in three 4-ha plots following the 2002 Hayman Fire...

  6. Mapping Post-Fire Vegetation Recovery at Different Lithologies of Taygetos mt (greece) with Multi-Temporal Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Vassilakis, Emmanuel; Mallinis, George; Christopoulou, Anastasia; Farangitakis, Georgios-Pavlos; Papanikolaou, Ioannis; Arianoutsou, Margarita

    2017-04-01

    Mt Taygetos (2407m), located at southern Peloponnese (Greece) suffered a large fire during the summer of 2007. The fire burned approximately 45% of the area covered by the endemic Greek fir (Abies cephalonica) and Black Pine (Pinus nigra) forest ecosystems. The aim of the current study is to examine the potential differences on post-fire vegetation recovery imposed by the lithology as well as the geomorphology of the given area over sites of the same climatic and landscape conditions (elevation, aspect, slope etc.). The main lithologies consist of carbonate, permeable, not easily erodible formations (limestones and marbles) and clastic, impermeable (schists, slate and flysch) erodible ones. A time-series of high spatial resolution satellite images were interpreted, analyzed and compared in order to detect changes in vegetation coverage which could prioritize areas of interest for fieldwork campaigns. The remote sensing datasets were acquired before (Ikonos-2), a few months after (Quickbird-2) and some years after (Worldview-3) the 2007 fire. High resolution Digital Elevation Model was used for the ortho-rectification and co-registration of the remote sensing data, but also for the extraction of the mountainous landscape characteristics. The multi-temporal image dataset was analyzed through GEographic-Object Based Image Analysis (GEOBIA). Objects corresponding to different vegetation types through time were identified through spectral and textural features. The classification results were combined with basic layers such as lithological outcrops, pre-fire vegetation, landscape morphology etc., supplementing a spatial geodatabase used for classifying burnt areas with varying post-fire plant community recovery. We validated the results of the classification during fieldwork and found that at a local scale, where the landscape features are quite similar, the bedrock type proves to be an important factor for vegetation recovery, as it clearly defines the soil generation

  7. Effect of post-fire resprouting on leaf fluctuating asymmetry, extrafloral nectar quality, and ant-plant-herbivore interactions

    NASA Astrophysics Data System (ADS)

    Alves-Silva, Estevão; Del-Claro, Kleber

    2013-06-01

    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.

  8. Post-Disturbance Plant Community Dynamics following a Rare Natural-Origin Fire in a Tsuga canadensis Forest

    PubMed Central

    Murray, Bryan D.; Holmes, Stacie A.; Webster, Christopher R.; Witt, Jill C.

    2012-01-01

    Opportunities to directly study infrequent forest disturbance events often lead to valuable information about vegetation dynamics. In mesic temperate forests of North America, stand-replacing crown fire occurs infrequently, with a return interval of 2000–3000 years. Rare chance events, however, may have profound impacts on the developmental trajectories of forest ecosystems. For example, it has been postulated that stand-replacing fire may have been an important factor in the establishment of eastern hemlock (Tsuga canadensis) stands in the northern Great Lakes region. Nevertheless, experimental evidence linking hemlock regeneration to non-anthropogenic fire is limited. To clarify this potential relationship, we monitored vegetation dynamics following a rare lightning-origin crown fire in a Wisconsin hemlock-hardwood forest. We also studied vegetation in bulldozer-created fire breaks and adjacent undisturbed forest. Our results indicate that hemlock establishment was rare in the burned area but moderately common in the scarified bulldozer lines compared to the reference area. Early-successional, non-arboreal species including Rubus spp., Vaccinium angustifolium, sedges (Carex spp.), grasses, Epilobium ciliatum, and Pteridium aquilinium were the most abundant post-fire species. Collectively, our results suggest that competing vegetation and moisture stress resulting from drought may reduce the efficacy of scarification treatments as well as the usefulness of fire for preparing a suitable seedbed for hemlock. The increasing prevalence of growing-season drought suggests that silvicultural strategies based on historic disturbance regimes may need to be reevaluated for mesic species. PMID:22928044

  9. Developing a post-fire flood chronology and recurrence probability from alluvial stratigraphy in the Buffalo Creek watershed, Colorado, USA

    USGS Publications Warehouse

    Elliott, J.G.; Parker, R.S.

    2001-01-01

    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

  10. Predicting Post-Fire Severity Effects in Coast Redwood Forests Using FARSITE

    Treesearch

    Hugh Scanlon; Yana Valachovic

    2006-01-01

    Assessing post-fire impacts in coast redwood (Sequoia sempervirens) forests can be difficult due to rough terrain, limited roads, and dense canopies. Remote sensing techniques can identify overstory damage, locating high intensity damage areas, although this can underestimate the effects on the understory vegetation and soils. To accurately assess...

  11. Prediction of spatially explicit rainfall intensity–duration thresholds for post-fire debris-flow generation in the western United States

    USGS Publications Warehouse

    Staley, Dennis M.; Negri, Jacquelyn; Kean, Jason W.; Laber, Jayme L.; Tillery, Anne C.; Youberg, Ann M.

    2017-01-01

    Early warning of post-fire debris-flow occurrence during intense rainfall has traditionally relied upon a library of regionally specific empirical rainfall intensity–duration thresholds. Development of this library and the calculation of rainfall intensity-duration thresholds often require several years of monitoring local rainfall and hydrologic response to rainstorms, a time-consuming approach where results are often only applicable to the specific region where data were collected. Here, we present a new, fully predictive approach that utilizes rainfall, hydrologic response, and readily available geospatial data to predict rainfall intensity–duration thresholds for debris-flow generation in recently burned locations in the western United States. Unlike the traditional approach to defining regional thresholds from historical data, the proposed methodology permits the direct calculation of rainfall intensity–duration thresholds for areas where no such data exist. The thresholds calculated by this method are demonstrated to provide predictions that are of similar accuracy, and in some cases outperform, previously published regional intensity–duration thresholds. The method also provides improved predictions of debris-flow likelihood, which can be incorporated into existing approaches for post-fire debris-flow hazard assessment. Our results also provide guidance for the operational expansion of post-fire debris-flow early warning systems in areas where empirically defined regional rainfall intensity–duration thresholds do not currently exist.

  12. Prediction of spatially explicit rainfall intensity-duration thresholds for post-fire debris-flow generation in the western United States

    NASA Astrophysics Data System (ADS)

    Staley, Dennis M.; Negri, Jacquelyn A.; Kean, Jason W.; Laber, Jayme L.; Tillery, Anne C.; Youberg, Ann M.

    2017-02-01

    Early warning of post-fire debris-flow occurrence during intense rainfall has traditionally relied upon a library of regionally specific empirical rainfall intensity-duration thresholds. Development of this library and the calculation of rainfall intensity-duration thresholds often require several years of monitoring local rainfall and hydrologic response to rainstorms, a time-consuming approach where results are often only applicable to the specific region where data were collected. Here, we present a new, fully predictive approach that utilizes rainfall, hydrologic response, and readily available geospatial data to predict rainfall intensity-duration thresholds for debris-flow generation in recently burned locations in the western United States. Unlike the traditional approach to defining regional thresholds from historical data, the proposed methodology permits the direct calculation of rainfall intensity-duration thresholds for areas where no such data exist. The thresholds calculated by this method are demonstrated to provide predictions that are of similar accuracy, and in some cases outperform, previously published regional intensity-duration thresholds. The method also provides improved predictions of debris-flow likelihood, which can be incorporated into existing approaches for post-fire debris-flow hazard assessment. Our results also provide guidance for the operational expansion of post-fire debris-flow early warning systems in areas where empirically defined regional rainfall intensity-duration thresholds do not currently exist.

  13. Establishment of non-native plant species after wildfires: Effects of fuel treatments, abiotic and biotic factors, and post-fire grass seeding treatments

    USGS Publications Warehouse

    Hunter, M.E.; Omi, Philip N.; Martinson, E.J.; Chong, G.W.

    2006-01-01

    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.

  14. Evaluation of vegetation post-fire resilience in the Alpine region using descriptors derived from MODIS spectral index time series

    NASA Astrophysics Data System (ADS)

    Di Mauro, Biagio; Fava, Francesco; Busetto, Lorenzo; Crosta, Giovanni Franco; Colombo, Roberto

    2013-04-01

    In this study a method based on the analysis of MODerate-resolution Imaging Spectroradiometer (MODIS) time series is proposed to estimate the post-fire resilience of mountain vegetation (broadleaf forest and prairies) in the Italian Alps. Resilience is defined herewith as the ability of a dynamical system to counteract disturbances. It can be quantified by the amount of time the disturbed system takes to resume, in statistical terms, an ecological functionality comparable with its undisturbed behavior. Satellite images of the Normalized Difference Vegetation Index (NDVI) and of the Enhanced Vegetation Index (EVI) with spatial resolution of 250m and temporal resolution of 16 days in the 2000-2012 time period were used. Wildfire affected areas in the Lombardy region between the years 2000 and 2010 were analysed. Only large fires (affected area >40ha) were selected. For each burned area, an undisturbed adjacent control site was located. Data pre-processing consisted in the smoothing of MODIS time series for noise removal and then a double logistic function was fitted. Land surface phenology descriptors (proxies for growing season start/end/length and green biomass) were extracted in order to characterize the time evolution of the vegetation. Descriptors from a burned area were compared to those extracted from the respective control site by means of the one-way analysis of variance. According to the number of subsequent years which exhibit statistically meaningful difference between burned and control site, five classes of resilience were identified and a set of thematic maps was created for each descriptor. The same method was applied to all 84 aggregated events and to events aggregated by main land cover. EVI index results more sensitive to fire impact than NDVI index. Analysis shows that fire causes both a reduction of the biomass and a variation in the phenology of the Alpine vegetation. Results suggest an average ecosystem resilience of 6-7 years. Moreover

  15. Monitoring the Effects of Forest Restoration Treatments on Post-Fire Vegetation Recovery with MODIS Multitemporal Data

    PubMed Central

    van Leeuwen, Willem J. D.

    2008-01-01

    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

  16. Effectiveness of post-fire Burned Area Emergency Response (BAER) road treatments: Results from three wildfires

    Treesearch

    Randy B. Foltz; Peter Robichaud

    2013-01-01

    Wildland fires often cause extreme changes in the landscape that drastically influence surface runoff and soil erosion, which can impact forest resources, aquatic habitats, water supplies, public safety, and forest access infrastructure such as forest roads. Little information is available on the effectiveness of various post-fire road treatments, thus this study was...

  17. Influence of Fire Mosaics, Habitat Characteristics and Cattle Disturbance on Mammals in Fire-Prone Savanna Landscapes of the Northern Kimberley.

    PubMed

    Radford, Ian J; Gibson, Lesley A; Corey, Ben; Carnes, Karin; Fairman, Richard

    2015-01-01

    Patch mosaic burning, in which fire is used to produce a mosaic of habitat patches representative of a range of fire histories ('pyrodiversity'), has been widely advocated to promote greater biodiversity. However, the details of desired fire mosaics for prescribed burning programs are often unspecified. Threatened small to medium-sized mammals (35 g to 5.5 kg) in the fire-prone tropical savannas of Australia appear to be particularly fire-sensitive. Consequently, a clear understanding of which properties of fire mosaics are most instrumental in influencing savanna mammal populations is critical. Here we use mammal capture data, remotely sensed fire information (i.e. time since last fire, fire frequency, frequency of late dry season fires, diversity of post-fire ages in 3 km radius, and spatial extent of recently burnt, intermediate and long unburnt habitat) and structural habitat attributes (including an index of cattle disturbance) to examine which characteristics of fire mosaics most influence mammals in the north-west Kimberley. We used general linear models to examine the relationship between fire mosaic and habitat attributes on total mammal abundance and richness, and the abundance of the most commonly detected species. Strong negative associations of mammal abundance and richness with frequency of late dry season fires, the spatial extent of recently burnt habitat (post-fire age <1 year within 3 km radius) and level of cattle disturbance were observed. Shrub cover was positively related to both mammal abundance and richness, and availability of rock crevices, ground vegetation cover and spatial extent of ≥4 years unburnt habitat were all positively associated with at least some of the mammal species modelled. We found little support for diversity of post-fire age classes in the models. Our results indicate that both a high frequency of intense late dry season fires and extensive, recently burnt vegetation are likely to be detrimental to mammals in the

  18. Pyrodiversity promotes avian diversity over the decade following forest fire.

    PubMed

    Tingley, Morgan W; Ruiz-Gutiérrez, Viviana; Wilkerson, Robert L; Howell, Christine A; Siegel, Rodney B

    2016-10-12

    An emerging hypothesis in fire ecology is that pyrodiversity increases species diversity. We test whether pyrodiversity-defined as the standard deviation of fire severity-increases avian biodiversity at two spatial scales, and whether and how this relationship may change in the decade following fire. We use a dynamic Bayesian community model applied to a multi-year dataset of bird surveys at 1106 points sampled across 97 fires in montane California. Our results provide strong support for a positive relationship between pyrodiversity and bird diversity. This relationship interacts with time since fire, with pyrodiversity having a greater effect on biodiversity at 10 years post-fire than at 1 year post-fire. Immediately after fires, patches of differing burn severities hold similar bird communities, but over the ensuing decade, bird assemblages within patches of contrasting severities differentiate. When evaluated at the scale of individual fires, fires with a greater heterogeneity of burn severities hold substantially more species. High spatial heterogeneity in severity, sometimes called 'mixed-severity fire', is a natural part of wildfire regimes in western North America, but may be jeopardized by climate change and a legacy of fire suppression. Forest management that encourages mixed-severity fire may be critical for sustaining biodiversity across fire-prone landscapes. © 2016 The Author(s).

  19. Pyrodiversity promotes avian diversity over the decade following forest fire

    PubMed Central

    Ruiz-Gutiérrez, Viviana; Wilkerson, Robert L.; Howell, Christine A.; Siegel, Rodney B.

    2016-01-01

    An emerging hypothesis in fire ecology is that pyrodiversity increases species diversity. We test whether pyrodiversity—defined as the standard deviation of fire severity—increases avian biodiversity at two spatial scales, and whether and how this relationship may change in the decade following fire. We use a dynamic Bayesian community model applied to a multi-year dataset of bird surveys at 1106 points sampled across 97 fires in montane California. Our results provide strong support for a positive relationship between pyrodiversity and bird diversity. This relationship interacts with time since fire, with pyrodiversity having a greater effect on biodiversity at 10 years post-fire than at 1 year post-fire. Immediately after fires, patches of differing burn severities hold similar bird communities, but over the ensuing decade, bird assemblages within patches of contrasting severities differentiate. When evaluated at the scale of individual fires, fires with a greater heterogeneity of burn severities hold substantially more species. High spatial heterogeneity in severity, sometimes called ‘mixed-severity fire', is a natural part of wildfire regimes in western North America, but may be jeopardized by climate change and a legacy of fire suppression. Forest management that encourages mixed-severity fire may be critical for sustaining biodiversity across fire-prone landscapes. PMID:27708152

  20. Post-mortem detection of gasoline residues in lung tissue and heart blood of fire victims.

    PubMed

    Pahor, Kevin; Olson, Greg; Forbes, Shari L

    2013-09-01

    The purpose of this study was to determine whether gasoline residues could be detected post-mortem in lung tissue and heart blood of fire victims. The lungs and heart blood were investigated to determine whether they were suitable samples for collection and could be collected without contamination during an autopsy. Three sets of test subjects (pig carcasses) were investigated under two different fire scenarios. Test subjects 1 were anaesthetized following animal ethics approval, inhaled gasoline vapours for a short period and then euthanized. The carcasses were clothed and placed in a house where additional gasoline was poured onto the carcass post-mortem in one fire, but not in the other. Test subjects 2 did not inhale gasoline, were clothed and placed in the house and had gasoline poured onto them in both fires. Test subjects 3 were clothed but had no exposure to gasoline either ante- or post-mortem. Following controlled burns and suppression with water, the carcasses were collected, and their lungs and heart blood were excised at a necropsy. The headspace from the samples was analysed using thermal desorption-gas chromatography-mass spectroscopy. Gasoline was identified in the lungs and heart blood from the subjects that were exposed to gasoline vapours prior to death (test subjects 1). All other samples were negative for gasoline residues. These results suggest that it is useful to analyse for volatile ignitable liquids in lung tissue and blood as it may help to determine whether a victim was alive and inhaling gases at the time of a fire.

  1. Interactions among wildland fires in a long-established Sierra Nevada natural fire area

    USGS Publications Warehouse

    Collins, B.M.; Miller, J.D.; Thode, A.E.; Kelly, M.; van Wagtendonk, J.W.; Stephens, S.L.

    2009-01-01

    We investigate interactions between successive naturally occurring fires, and assess to what extent the environments in which fires burn influence these interactions. Using mapped fire perimeters and satellite-based estimates of post-fire effects (referred to hereafter as fire severity) for 19 fires burning relatively freely over a 31-year period, we demonstrate that fire as a landscape process can exhibit self-limiting characteristics in an upper elevation Sierra Nevada mixed conifer forest. We use the term 'self-limiting' to refer to recurring fire as a process over time (that is, fire regime) consuming fuel and ultimately constraining the spatial extent and lessening fire-induced effects of subsequent fires. When the amount of time between successive adjacent fires is under 9 years, and when fire weather is not extreme (burning index <34.9), the probability of the latter fire burning into the previous fire area is extremely low. Analysis of fire severity data by 10-year periods revealed a fair degree of stability in the proportion of area burned among fire severity classes (unchanged, low, moderate, high). This is in contrast to a recent study demonstrating increasing high-severity burning throughout the Sierra Nevada from 1984 to 2006, which suggests freely burning fires over time in upper elevation Sierra Nevada mixed conifer forests can regulate fire-induced effects across the landscape. This information can help managers better anticipate short- and long-term effects of allowing naturally ignited fires to burn, and ultimately, improve their ability to implement Wildland Fire Use programs in similar forest types. ?? 2008 Springer Science+Business Media, LLC.

  2. Pre-wildfire management treatments interact with fire severity to have lasting effects on post-wildfire vegetation response

    Treesearch

    Kristen L. Shive; Carolyn H. Sieg; Peter Z. Fule

    2013-01-01

    Land managers are routinely applying fuel reduction treatments to mitigate the risk of severe, stand-replacing fire in ponderosa pine communities of the southwestern US. When these treatments are burned by wildfire they generally reduce fire severity, but less is known about how they influence post-wildfire vegetation recovery, as compared to pre-fire untreated areas....

  3. A database on post-fire erosion rates and debris flows in Mediterranean-Basin watersheds

    NASA Astrophysics Data System (ADS)

    Parise, M.; Cannon, S. H.

    2009-04-01

    Wildfires can affect many Mediterranean countries on a yearly bases, producing damage and economic losses, both as direct effect of the fires and as consequent events, including erosion and sedimentation in the recently burned areas. Even though most of the wildfires occur in Spain, Portugal, southern France, Italy and Greece, it can be stated that no one of the Mediterranean countries is completely immune by such hazards. In addition to destruction of the vegetation, and in addition to direct losses to the built-up environment, further effects may also be registered as a consequence of the fire, even weeks or months after its occurrence. Wildfire can have, in fact, profound effects on the hydrologic response of watersheds, and debris-flow activity is among the most destructive consequences of these effects, often causing extensive damage to human infrastructure. Wildfires are today continuously monitored by several European institutions, and forecasting of the conditions (weather, temperature, wind, etc.) more likely conducive to their occurrence is often available in real time. On the other hand, not much is known about the processes that occur as a consequence of the fire, including erosion and debris flows. These are often underestimated, and become object of study only after some catastrophic event has occurred. This is in strong contrast with all the established techniques of risk mitigation; as a result, no prevention action is generally considered, and the society relies only on the emergency phase following a disaster. Aimed at contributing to gather information about the occurrence of erosional and debris-flow activity in recently burned Mediterranean areas, and at making available these information to land planners and scientists, a specific database has been compiled and presented in this contribution. To date, scientific literature on the topic in Europe has never been catalogued, and was dispersed in a number of different journals and in conference

  4. Nitrogen balance along a northern boreal forest fire chronosequence.

    PubMed

    Palviainen, Marjo; Pumpanen, Jukka; Berninger, Frank; Ritala, Kaisa; Duan, Baoli; Heinonsalo, Jussi; Sun, Hui; Köster, Egle; Köster, Kajar

    2017-01-01

    Fire is a major natural disturbance factor in boreal forests, and the frequency of forest fires is predicted to increase due to climate change. Nitrogen (N) is a key determinant of carbon sequestration in boreal forests because the shortage of N limits tree growth. We studied changes in N pools and fluxes, and the overall N balance across a 155-year non stand-replacing fire chronosequence in sub-arctic Pinus sylvestris forests in Finland. Two years after the fire, total ecosystem N pool was 622 kg ha-1 of which 16% was in the vegetation, 8% in the dead biomass and 76% in the soil. 155 years after the fire, total N pool was 960 kg ha-1, with 27% in the vegetation, 3% in the dead biomass and 69% in the soil. This implies an annual accumulation rate of 2.28 kg ha-1 which was distributed equally between soil and biomass. The observed changes in N pools were consistent with the computed N balance +2.11 kg ha-1 yr-1 over the 155-year post-fire period. Nitrogen deposition was an important component of the N balance. The biological N fixation increased with succession and constituted 9% of the total N input during the 155 post-fire years. N2O fluxes were negligible (≤ 0.01 kg ha-1 yr-1) and did not differ among post-fire age classes. The number and intensity of microbial genes involved in N cycling were lower at the site 60 years after fire compared to the youngest and the oldest sites indicating potential differences in soil N cycling processes. The results suggest that in sub-arctic pine forests, the non-stand-replacing, intermediate-severity fires decrease considerably N pools in biomass but changes in soil and total ecosystem N pools are slight. Current fire-return interval does not seem to pose a great threat to ecosystem productivity and N status in these sub-arctic forests.

  5. Nitrogen balance along a northern boreal forest fire chronosequence

    PubMed Central

    Pumpanen, Jukka; Berninger, Frank; Ritala, Kaisa; Duan, Baoli; Heinonsalo, Jussi; Sun, Hui; Köster, Egle; Köster, Kajar

    2017-01-01

    Fire is a major natural disturbance factor in boreal forests, and the frequency of forest fires is predicted to increase due to climate change. Nitrogen (N) is a key determinant of carbon sequestration in boreal forests because the shortage of N limits tree growth. We studied changes in N pools and fluxes, and the overall N balance across a 155-year non stand-replacing fire chronosequence in sub-arctic Pinus sylvestris forests in Finland. Two years after the fire, total ecosystem N pool was 622 kg ha-1 of which 16% was in the vegetation, 8% in the dead biomass and 76% in the soil. 155 years after the fire, total N pool was 960 kg ha-1, with 27% in the vegetation, 3% in the dead biomass and 69% in the soil. This implies an annual accumulation rate of 2.28 kg ha-1 which was distributed equally between soil and biomass. The observed changes in N pools were consistent with the computed N balance +2.11 kg ha-1 yr-1 over the 155-year post-fire period. Nitrogen deposition was an important component of the N balance. The biological N fixation increased with succession and constituted 9% of the total N input during the 155 post-fire years. N2O fluxes were negligible (≤ 0.01 kg ha-1 yr-1) and did not differ among post-fire age classes. The number and intensity of microbial genes involved in N cycling were lower at the site 60 years after fire compared to the youngest and the oldest sites indicating potential differences in soil N cycling processes. The results suggest that in sub-arctic pine forests, the non-stand-replacing, intermediate-severity fires decrease considerably N pools in biomass but changes in soil and total ecosystem N pools are slight. Current fire-return interval does not seem to pose a great threat to ecosystem productivity and N status in these sub-arctic forests. PMID:28358884

  6. Post-fire wood management alters water stress, growth, and performance of pine regeneration in a Mediterranean ecosystem

    USGS Publications Warehouse

    Maranon-Jimenez, Sara; Castro, Jorge; Querejeta, José Ignacio; Fernandez-Ondono, Emilia; Allen, Craig D.

    2013-01-01

    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

  7. Post-fire salvage logging alters species composition and reduces cover, richness, and diversity in Mediterranean plant communities.

    PubMed

    Leverkus, Alexandro B; Lorite, Juan; Navarro, Francisco B; Sánchez-Cañete, Enrique P; Castro, Jorge

    2014-01-15

    An intense debate exists on the effects of post-fire salvage logging on plant community regeneration, but scant data are available derived from experimental studies. We analyzed the effects of salvage logging on plant community regeneration in terms of species richness, diversity, cover, and composition by experimentally managing a burnt forest on a Mediterranean mountain (Sierra Nevada, S Spain). In each of three plots located at different elevations, three replicates of three treatments were implemented seven months after the fire, differing in the degree of intervention: "Non-Intervention" (all trees left standing), "Partial Cut plus Lopping" (felling 90% of the trees, cutting the main branches, and leaving all the biomass in situ), and "Salvage Logging" (felling and piling the logs, and masticating the woody debris). Plant composition in each treatment was monitored two years after the fire in linear point transects. Post-fire salvage logging was associated with reduced species richness, Shannon diversity, and total plant cover. Moreover, salvaged sites hosted different species assemblages and 25% lower cover of seeder species (but equal cover of resprouters) compared to the other treatments. Cover of trees and shrubs was also lowest in Salvage Logging, which could suggest a potential slow-down of forest regeneration. Most of these results were consistent among the three plots despite plots hosting different plant communities. Concluding, our study suggests that salvage logging may reduce species richness and diversity, as well as the recruitment of woody species, which could delay the natural regeneration of the ecosystem. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Grass seedling growth and survival under different post-fire grazing management scenarios

    USDA-ARS?s Scientific Manuscript database

    As wildfires have increased in frequency and size throughout the Great Basin, post-fire rehabilitation activities have become important in reestablishing resilient sagebrush steppe communities. Many rehabilitation treatments fail when perennial grass seedlings do not establish. This can be due to pr...

  9. Modeling In-Stream Hydro-Geomorphic Processes After 2012 Waldo Canyon Fire, Colorado

    NASA Astrophysics Data System (ADS)

    Nourbakhshbeidokhti, S.; Kinoshita, A. M.; Chin, A.

    2016-12-01

    Wildfires can have significant impacts on hydrologic and geomorphic processes. Post-fire sediment transport and runoff generation vary by burn severity, precipitation, and vegetation. A need exists to understand these variable relationships and improve parameterization of post-fire hydro-geomorphic models. This research aims to model pre-fire geomorphic and hydrologic processes in Williams Canyon, a watershed burned by the 2012 Waldo Canyon Fire in Colorado. We develop the KINematic Runoff and EROSion (KINEROS) model with Geographical Information System (GIS)-based information, including a Digital Elevation Model, land cover, soil classification, precipitation, and soil burn severity for a local reference watershed that is unburned. We transfer these parameters to a channel reach in Williams Canyon (Williams Downstream) and adjust them toward post-fire conditions. We model runoff and sediment yield for several storms following the fire. Three post-fire terrestrial Light Detection and Ranging (LiDAR) images (21 April 2013, 14 September 2013, and 16 September 2014) are used to estimate total erosion and deposition at the reach scale. We use the LiDAR-based information to calibrate the post-fire model. Preliminary modeling results indicate 3870-125 kg/ha of sediment in the Williams Downstream reach. The uncalibrated model overestimated (410% in the first year) and underestimated (87.2% in the second year) the erosion. Model calibration reduced the Root Mean Square Error (RMSE) of sediment to 0.016% for the first year and 0.09% for the second year. The parameters calibrated for the Williams Downstream channel reach will be used to develop models for seven other channel reaches within the area burned by the Waldo Canyon Fire, where the performance can be evaluated with LiDAR estimates. Results of this research will enhance our understanding of wildfire disturbance on coupled hydrologic and geomorphic processes. Findings will also improve model parameterization that can

  10. Modeling post-fire woody carbon dynamics with data from remeasured inventory plots

    Treesearch

    Bianca N.I. Eskelson; Jeremy Fried; Vicente Monleon

    2015-01-01

    In California, the Forest Inventory and Analysis (FIA) plots within large fires were visited one year after the fire occurred resulting in a time series of measurements before and after fire. During this additional plot visit, the standard inventory measurements were augmented for these burned plots to assess fire effects. One example of the additional measurements is...

  11. Physiological and morphological responses of pine and willow saplings to post-fire salvage logging

    NASA Astrophysics Data System (ADS)

    Millions, E. L.; Letts, M. G.; Harvey, T.; Rood, S. B.

    2015-12-01

    With global warming, forest fires may be increasing in frequency, and post-fire salvage logging may become more common. The ecophysiological impacts of this practice on tree saplings remain poorly understood. In this study, we examined the physiological and morphological impacts of increased light intensity, due to post-fire salvage logging, on the conifer Pinus contorta (pine) and deciduous broadleaf Salix lucida (willow) tree and shrub species in the Crowsnest Pass region of southern Alberta. Photosynthetic gas-exchange and plant morphological measurements were taken throughout the summer of 2013 on approximately ten year-old saplings of both species. Neither species exhibited photoinhibition, but different strategies were observed to acclimate to increased light availability. Willow saplings were able to slightly elevate their light-saturated rate of net photosynthesis (Amax) when exposed to higher photosynthetic photon flux density (PPFD), thus increasing their growth rate. Willow also exhibited increased leaf inclination angles and leaf mass per unit area (LMA), to decrease light interception in the salvage-logged plot. By contrast, pine, which exhibited lower Amax and transpiration (E), but higher water-use efficiency (WUE = Amax/E) than willow, increased the rate at which electrons were moved through and away from the photosynthetic apparatus in order to avoid photoinhibition. Acclimation indices were higher in willow saplings, consistent with the hypothesis that species with short-lived foliage exhibit greater acclimation. LMA was higher in pine saplings growing in the logged plot, but whole-plant and branch-level morphological acclimation was limited and more consistent with a response to decreased competition in the logged plot, which had much lower stand density.

  12. The Effectiveness of Aerial Hydromulch as a Post-Fire Erosion Control Treatment in Southern California

    Treesearch

    P.M. Wohlgemuth; J.L. Beyers; P.R. Robichaud

    2010-01-01

    Following a wildfire in the Santa Ana Mountains of northeast Orange County, California, a monitoring project was established to test whether aerial hydromulch reduced post-fire hillslope and small watershed erosion, and to document its impact on re-growing vegetation. The study site received below normal rainfall both the first and second winters after the fire. A high...

  13. Fire effects on the Point Reyes Mountain Beaver (Aplodontia rufa phaea) at Point Reyes National Seashore, 10 years after the Vision Fire

    USGS Publications Warehouse

    Fellers, Gary M.; Osbourn, Michael

    2009-01-01

    The 1995 Vision Fire burned 5000 ha and destroyed 40% of the habitat of the Point Reyes Mountain Beaver (Aplodontia rufa phaea). Surveys immediately post-fire and in 2000 showed that only 0.4 to 1.7% of Mountain Beavers within the burn area survived. In 2000, dense, ground-hugging Blue-blossom Ceanothus (Ceanothus thrysiflorus) appeared to make coastal scrub thickets much less suitable for Mountain Beavers even though the number of burrows at our 11 study sites had returned to 88% of pre-fire numbers. In 2005 (10 y post-fire), the habitat appeared to be better for Mountain Beavers; Blue-blossom Ceanothus had diminished and vegetation more typical of northern coastal scrub, such as Coyote Brush (Baccharis pilularis) overstory with a lower layer of herbaceous vegetation, had greatly increased; but the number of Mountain Beaver burrows had declined to 52% of pre-fire numbers and there was little change in the number of sites occupied between our 2000 and 2005 surveys. With the expected successional changes in thicket structure, Mountain Beaver populations are likely to recover further, but there will probably be considerable variation in how each population stabilizes.

  14. Formation of post-fire water-repellent layers in Monterrey pine (Pinus radiata D. Don) plantations in south-central Chile

    Treesearch

    P. Garcia-Chevesich; R. Pizarro; C. L. Stropki; P. Ramirez de Arellano; P. F. Ffolliott; L. F. DeBano; Dan Neary; D. C. Slack

    2010-01-01

    A wildfire burned about 15,000 ha of Monterrey Pine (Pinus radiata D. Don) plantations near Yungay, Chile, in January of 2007. Post-fire water repellency (hydrophobicity) was measured using the water-drop-penetration-time (WDPT) method at depths of 0, 5, and 10 mm from the soil surface. These measurements were collected on burned sites of both young (4-years old) and...

  15. Yellow pine regeneration as a function of fire severity and post-burn stand structure in the southern Appalachian Mountains

    Treesearch

    Michael A. Jenkins; Robert N. Klein; Virginia L. McDaniel

    2011-01-01

    We used pre- and post-burn fire effects data from six prescribed burns to examine post-burn threshold effects of stand structure (understory density, overstory density, shrub cover, duff depth, and total fuel load) on the regeneration of yellow pine (Pinus subgenus Diploxylon) seedlings and cover of herbaceous vegetation in six prescribed-fire management units located...

  16. Evidence-based review of seeding in post-fire rehabilitation and native plant market feasibility

    Treesearch

    Donna L. Peppin

    2009-01-01

    A changing climate and fire regime shifts in the western United States have led to an increase in revegetation activities, in particular post-wildfire rehabilitation and the need for locally-adapted plant materials. Broadcast seeding is one of the most widely used post-wildfire emergency response treatments to minimize soil erosion, promote plant community recovery,...

  17. Boreal Forest Fire Cools Climate

    NASA Astrophysics Data System (ADS)

    Randerson, J. T.; Liu, H.; Flanner, M.; Chambers, S. D.; Harden, J. W.; Hess, P. G.; Jin, Y.; Mack, M. C.; Pfister, G.; Schuur, E. A.; Treseder, K. K.; Welp, L. R.; Zender, C. S.

    2005-12-01

    We report measurements, modeling, and analysis of carbon and energy fluxes from a boreal forest fire that occurred in interior Alaska during 1999. In the first year after the fire, ozone production, atmospheric aerosol loading, greenhouse gas emissions, soot deposition, and decreases in summer albedo contributed to a positive annual radiative forcing (RF). These effects were partly offset by an increase in fall, winter, and spring albedo from reduced canopy cover and increased exposure of snow-covered surfaces. The atmospheric lifetime of aerosols and ozone and are relatively short (days to months). The radiative effects of soot on snow are also attenuated rapidly from the deposition of fresh snow. As a result, a year after the fire, only two classes of RF mechanisms remained: greenhouse gas emissions and post-fire changes in surface albedo. Summer albedo increased rapidly in subsequent years and was substantially higher than unburned control areas (by more than 0.03) after 4 years as a result of grass and shrub establishment. Satellite measurements from MODIS of other interior Alaska burn scars provided evidence that elevated levels of spring and summer albedo (relative to unburned control areas) persisted for at least 4 decades after fire. In parallel, our chamber, eddy covariance, and biomass measurements indicated that the post-fire ecosystems switch from a source to a sink within the first decade. Taken together, the extended period of increased spring and summer albedo and carbon uptake of intermediate-aged stands appears to more than offset the initial warming pulse caused by fire emissions, when compared using the RF concept. This result suggests that management of forests in northern countries to suppress fire and preserve carbon sinks may have the opposite effect on climate as that intended.

  18. Annual runoff and erosion in a recently burn Mediterranean forest - The effects of plowing and time-since-fire

    NASA Astrophysics Data System (ADS)

    Vieira, D. C. S.; Malvar, M. C.; Fernández, C.; Serpa, D.; Keizer, J. J.

    2016-10-01

    The impacts of forest fires on runoff and soil erosion have been assessed by many studies, so the effects of fires on the hydrological and geomorphological processes of burnt forest areas, globally and in the Mediterranean region, are well established. Few studies, however, have assessed post-fire runoff and erosion on large time scales. In addition, a limited number of studies are available that consider the effect of pre-fire land management practices on post-fire runoff and erosion. This study evaluated annual runoff and sediment losses, at micro plot scale, for 4 years after a wildfire in three eucalypt plantations with different pre-fire land management practices (i.e., plowed and unplowed). During the four years following the fire, runoff amounts and coefficients at the downslope plowed (1257 mm, 26%) and contour plowed eucalypt sites (1915 mm, 40%) were higher than at the unplowed site (865 mm, 14%). Sediment losses over the 4 years of study were also consistently higher at the two plowed sites (respectively, 0.47 and 0.83 Mg ha- 1 y- 1 at the downslope and contour plowed eucalypt site) than at the unplowed site (0.11 Mg ha- 1 y- 1). Aside from pre-fire land management, time-since-fire also seemed to significantly affect post-fire annual runoff and erosion. In general, annual runoff amounts and erosion rates followed the rainfall pattern. Runoff amounts presented a peak during the third year of monitoring while erosion rates reached their maximum one year earlier, in the second year. Runoff coefficients increased over the 4 years of monitoring, in disagreement to the window of disturbance post-fire recovery model, but sediment concentrations decreased over the study period. When compared with other long-term post-fire studies and with studies evaluating the effects of pre- and post-fire management practices, the results of the present work suggest that an ecosystem's recovery after fire is highly dependent on the background of disturbances of each site, as

  19. Turbidity Responses from Timber Harvesting, Wildfire, and Post-Fire Logging in the Battle Creek Watershed, Northern California.

    PubMed

    Lewis, Jack; Rhodes, Jonathan J; Bradley, Curtis

    2018-04-11

    The Battle Creek watershed in northern California was historically important for its Chinook salmon populations, now at remnant levels due to land and water uses. Privately owned portions of the watershed are managed primarily for timber production, which has intensified since 1998, when clearcutting became widespread. Turbidity has been monitored by citizen volunteers at 13 locations in the watershed. Approximately 2000 grab samples were collected in the 5-year analysis period as harvesting progressed, a severe wildfire burned 11,200 ha, and most of the burned area was salvage logged. The data reveal strong associations of turbidity with the proportion of area harvested in watersheds draining to the measurement sites. Turbidity increased significantly over the measurement period in 10 watersheds and decreased at one. Some of these increases may be due to the influence of wildfire, logging roads and haul roads. However, turbidity continued trending upwards in six burned watersheds that were logged after the fire, while decreasing or remaining the same in two that escaped the fire and post-fire logging. Unusually high turbidity measurements (more than seven times the average value for a given flow condition) were very rare (0.0% of measurements) before the fire but began to appear in the first year after the fire (5.0% of measurements) and were most frequent (11.6% of measurements) in the first 9 months after salvage logging. Results suggest that harvesting contributes to road erosion and that current management practices do not fully protect water quality.

  20. Evaluating Post-Fire Forest Resilience Using GIS and Multi-Criteria Analysis: An Example from Cape Sounion National Park, Greece

    NASA Astrophysics Data System (ADS)

    Arianoutsou, Margarita; Koukoulas, Sotirios; Kazanis, Dimitrios

    2011-03-01

    Forest fires are one of the major causes of ecological disturbance in the mediterranean climate ecosystems of the world. Despite the fact that a lot of resources have been invested in fire prevention and suppression, the number of fires occurring in the Mediterranean Basin in the recent decades has continued to markedly increase. The understanding of the relationship between landscape and fire lies, among others, in the identification of the system's post-fire resilience. In our study, ecological and landscape data are integrated with decision-support techniques in a Geographic Information Systems (GIS) framework to evaluate the risk of losing post-fire resilience in Pinus halepensis forests, using Cape Sounion National Park, Central Greece, as a pilot case. The multi-criteria decision support approach has been used to synthesize both bio-indicators (woody cover, pine density, legume cover and relative species richness and annual colonizers) and geo-indicators (fire history, parent material, and slope inclination) in order to rank the landscape components. Judgments related to the significance of each factor were incorporated within the weights coefficients and then integrated into the multicriteria rule to map the risk index. Sensitivity analysis was very critical for assessing the contribution of each factor and the sensitivity to subjective weight judgments to the final output. The results of this study include a final ranking map of the risk of losing resilience, which is very useful in identifying the "risk hotspots", where post-fire management measures should be applied in priority.

  1. Evaluating post-fire forest resilience using GIS and multi-criteria analysis: an example from Cape Sounion National Park, Greece.

    PubMed

    Arianoutsou, Margarita; Koukoulas, Sotirios; Kazanis, Dimitrios

    2011-03-01

    Forest fires are one of the major causes of ecological disturbance in the mediterranean climate ecosystems of the world. Despite the fact that a lot of resources have been invested in fire prevention and suppression, the number of fires occurring in the Mediterranean Basin in the recent decades has continued to markedly increase. The understanding of the relationship between landscape and fire lies, among others, in the identification of the system's post-fire resilience. In our study, ecological and landscape data are integrated with decision-support techniques in a Geographic Information Systems (GIS) framework to evaluate the risk of losing post-fire resilience in Pinus halepensis forests, using Cape Sounion National Park, Central Greece, as a pilot case. The multi-criteria decision support approach has been used to synthesize both bio-indicators (woody cover, pine density, legume cover and relative species richness and annual colonizers) and geo-indicators (fire history, parent material, and slope inclination) in order to rank the landscape components. Judgments related to the significance of each factor were incorporated within the weights coefficients and then integrated into the multicriteria rule to map the risk index. Sensitivity analysis was very critical for assessing the contribution of each factor and the sensitivity to subjective weight judgments to the final output. The results of this study include a final ranking map of the risk of losing resilience, which is very useful in identifying the "risk hotspots", where post-fire management measures should be applied in priority.

  2. Soil Microbial Activity Responses to Fire in a Semi-arid Savannah Ecosystem Pre- and Post-Monsoon Season

    NASA Astrophysics Data System (ADS)

    Jimenez, J. R.; Raub, H. D.; Jong, E. L.; Muscarella, C. R.; Smith, W. K.; Gallery, R. E.

    2017-12-01

    Extracellular enzyme activities (EEA) of soil microorganisms can act as important proxies for nutrient limitation and turnover in soil and provide insight into the biochemical requirements of microbes in terrestrial ecosystems. In semi-arid ecosystems, microbial activity is influenced by topography, disturbances such as fire, and seasonality from monsoon rains. Previous studies from forest ecosystems show that microbial communities shift to similar compositions after severe fires despite different initial conditions. In semi-arid ecosystems with high spatial heterogeniety, we ask does fire lead to patch intensification or patch homogenization and how do monsoon rains influence the successional trajectories of microbial responses? We analyzed microbial activity and soil biogeochemistry throughout the monsoon season in paired burned and unburned sites in the Santa Rita Experimental Range, AZ. Surface soil (5cm) from bare-ground patches, bole, canopy drip line, and nearby grass patches for 5 mesquite trees per site allowed tests of spatiotemporal responses to fire and monsoon rain. Microbial activity was low during the pre-monsoon season and did not differ between the burned and unburned sites. We found greater activity near mesquite trees that reflects soil water and nutrient availability. Fire increased soil alkalinity, though soils near mesquite trees were less affected. Soil water content was significantly higher in the burned sites post-monsoon, potentially reflecting greater hydrophobicity of burned soils. Considering the effects of fire in these semi-arid ecosystems is especially important in the context of the projected changing climate regime in this region. Assessing microbial community recovery pre-, during, and post-monsoon is important for testing predictions about whether successional pathways post-fire lead to recovery or novel trajectories of communities and ecosystem function.

  3. Comparing and Linking Post-fire Hillslope Erosion and Channel Change for Different Storm Types

    NASA Astrophysics Data System (ADS)

    MacDonald, Lee; Kampf, Stephanie; Brogan, Dan; Schmeer, Sarah; Nelson, Peter

    2016-04-01

    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

  4. Post-fire mulching and soil hydrological response

    NASA Astrophysics Data System (ADS)

    Jordán, Antonio; Zavala, Lorena M.; Gordillo-Rivero, Ángel J.; Muñoz-Rojas, Miriam; Keesstra, Saskia; Cerdà, Artemi

    2017-04-01

    In general, one of the major threats after a forest fire is the increased erosion. This can occur due to the erosive impact of rainfall after a drastic reduction of vegetation cover or to changes in soil surface properties that contribute to enhanced runoff flow. There is a consensus among researchers that one of the best ways to reduce this risk is to apply a mulch cover (straw, shredded wood or other materials) immediately after fire. In this study, we studied the effectiveness of various types of mulch materials for the reduction of runoff and soil loss during the first 3 years after a forest fire, in plots of different sizes, with special attention to water repellency and physical properties of the soil surface. In general, straw mulch reduced both runoff and erosion rate more than other treatments. However, the effect was much more important on larger plots. This may be due to specific processes and impacts on sediment connectivity and surface water flow. Therefore, the effect of the scale seems to be an important factor in the management of burnt soils.

  5. Post-fire Thermokarst Development Along a Planned Road Corridor in Arctic Alaska

    NASA Astrophysics Data System (ADS)

    Jones, B. M.; Grosse, G.; Larsen, C. F.; Hayes, D. J.; Arp, C. D.; Liu, L.; Miller, E.

    2015-12-01

    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

  6. Post-fire management regimes affect carbon sequestration and storage in a Sierra Nevada mixed conifer forest

    Treesearch

    Elizabeth M. Powers; John D. Marshall; Jianwei Zhang; Liang Wei

    2013-01-01

    Forests mitigate climate change by sequestering CO2 from the atmosphere and accumulating it in biomass storage pools. However, in dry conifer forests, fire occasionally returns large quantities of CO2 to the atmosphere. Both the total amount of carbon stored and its susceptibility to loss may be altered by post-fire land...

  7. Fire effects on the Point Reyes Mountain Beaver at Point Reyes National Seashore, California

    USGS Publications Warehouse

    Fellers, Gary M.; Pratt, David; Griffin, Jennifer L.

    2004-01-01

    In October 1995, a wildlands fire burned 5,000 ha on the Point Reyes peninsula, California, USA. In most of the nonforested areas, the fire effectively cleared the ground of litter and vegetation and revealed thousands of Point Reyes mountain beaver (Aplodontia rufa phaea) burrow openings. In the first 6 months after the fire, we surveyed burned coastal scrub and riparian habitat to (1) count the number of burrow openings that existed at the time of the fire, and (2) evaluate whether signs of post-fire mountain beaver activity were evident. We estimated that only 0.4–1.7% of mountain beavers within the burn area survived the fire and immediate post-fire period. We monitored mountain beaver activity for 5 years at 8 sites where mountain beavers survived, and found little or no recovery. We estimate that the mountain beaver population will take 15–20 years post-fire to recover.

  8. Post-wildfire erosion in mountainous terrain leads to rapid and major redistribution of soil organic carbon

    NASA Astrophysics Data System (ADS)

    Abney, Rebecca B.; Sanderman, Jonathan; Johnson, Dale; Fogel, Marilyn L.; Berhe, Asmeret Asefaw

    2017-11-01

    Catchments impacted by wildfire typically experience elevated rates of post-fire erosion and formation and deposition of pyrogenic carbon (PyC). To better understand the role of erosion in post-fire soil carbon dynamics, we determined distribution of soil organic carbon in different chemical fractions before and after the Gondola fire in South Lake Tahoe, CA. We analyzed soil samples from eroding and depositional landform positions in control and burned plots pre- and post-wildfire (in 2002, 2003, and 10-years post-fire in 2013). We determined elemental concentrations, stable isotope compositions, and biochemical composition of organic matter (OM) using mid-infrared (MIR) spectroscopy for all of the samples. A subset of samples was analyzed by 13C cross polarization magic angle spinning nuclear magnetic resonance spectroscopy (CPMAS 13C-NMR). We combined the MIR and CPMAS 13C-NMR data in the Soil Carbon Research Program partial least squares regression model to predict distribution of soil carbon into three different fractions: 1) particulate, humic, and resistant organic matter fractions representing relatively fresh larger pieces of OM, 2) fine, decomposed OM, and 3) pyrogenic C, respectively. Samples from the post-fire eroding landform position showed no major difference in soil organic carbon (SOC) fractions one year post-fire. The depositional samples, however, had increased concentrations of all SOC fractions, particularly the fraction that resembles PyC, one year post-fire (2002), which had a mean of 160 g/kg compared with burned hillslope soils, which had 84 g/kg. The increase in all SOC fractions in the post-fire depositional landform position one year post-fire indicates significant lateral mobilization of the eroded PyC. In addition, our NMR analyses revealed a post-fire increase in both the aryl and O-aryl carbon compounds in the soils from the depositional landform position, indicating increases in soil PyC concentrations post-fire. After 10 years, the

  9. Microbial community recovery post-fire in a high elevation mixed conifer catchment in response to varied precipitation regime.

    NASA Astrophysics Data System (ADS)

    Fairbanks, D.; Cook, C.; Chorover, J.; Gallery, R. E.; Rich, V. I.

    2016-12-01

    Fire frequency and severity are increasing across the western United States with enormous impacts on regional carbon and nutrient cycling. Central to the understanding of ecosystem recovery are the microbial communities that transform nutrients in the environment. Temporal changes in precipitation patterns influence the stress response of resident microbiota, in combination with abiotic controls, and in part, controls ecosystem level CO2 and greenhouse gas flux. We explored the relationship between timing of precipitation, terrestrial nutrient cycles on microbial ecology post- fire by sampling across a topographic gradient from two adjacent mountain catchments (north and south-facing) in a high elevation mixed conifer forest three years following a high severity fire disturbance. To best understand microbial community response and recovery to a) a major fire disturbance and b) pulsed precipitation dynamics we analyzed the 16S ribosomal rRNA community metrics, seven hydrolytic enzyme activities, biomass carbon and nitrogen and geochemical parameters following snowmelt, pre and post-monsoon. Six sites were sampled from each catchment across a topographic transect from surface (0-10 cm) and deep (30-40 cm) soil profiles. Samples taken from the south facing catchment were co-located with CO2, O2, redox (platinum electrode) and temperature probes. Results show greater greenhouse gas flux in the convergent zones of the landscape occurring at deeper depths with simultaneous oxygen consumption. These results can be used to integrate our understanding of `hot spots' as a function of landscape position and the pulse coupling of precipitation dynamics influencing the stress response of microbes and the co-occurring nutrient cycling.

  10. Moving beyond the cambium necrosis hypothesis of post-fire tree mortality: cavitation and deformation of xylem in forest fires

    Treesearch

    S.T. Michaletz; E.A. Johnson; M.T. Tyree

    2012-01-01

    It is widely assumed that post-fire tree mortality results from necrosis of phloem and vascular cambium in stems, despite strong evidence that reduced xylem conductivity also plays an important role. In this study, experiments with Populus balsamifera were used to demonstrate two mechanisms by which heat reduces the hydraulic conductivity of xylem:...

  11. Prescribed Fire Effects on Runoff, Erosion, and Soil Water Repellency on Steeply-Sloped Sagebrush Rangeland over a Five Year Period

    NASA Astrophysics Data System (ADS)

    Williams, C. J.; Pierson, F. B.; Al-Hamdan, O. Z.

    2014-12-01

    Fire is an inherent component of sagebrush steppe rangelands in western North America and can dramatically affect runoff and erosion processes. Post-fire flooding and erosion events pose substantial threats to proximal resources, property, and human life. Yet, prescribed fire can serve as a tool to manage vegetation and fuels on sagebrush rangelands and to reduce the potential for large catastrophic fires and mass erosion events. The impact of burning on event hydrologic and erosion responses is strongly related to the degree to which burning alters vegetation, ground cover, and surface soils and the intensity and duration of precipitation. Fire impacts on hydrologic and erosion response may be intensified or reduced by inherent site characteristics such as topography and soil properties. Parameterization of these diverse conditions in predictive tools is often limited by a lack of data and/or understanding for the domain of interest. Furthermore, hydrologic and erosion functioning change as vegetation and ground cover recover in the years following burning and few studies track these changes over time. In this study, we evaluated the impacts of prescribed fire on vegetation, ground cover, soil water repellency, and hydrologic and erosion responses 1, 2, and 5 yr following burning of a mountain big sagebrush community on steep hillslopes with fine-textured soils. The study site is within the Reynolds Creek Experimental Watershed, southwestern Idaho, USA. Vegetation, ground cover, and soil properties were measured over plot scales of 0.5 m2 to 9 m2. Rainfall simulations (0.5 m2) were used to assess the impacts of fire on soil water repellency, infiltration, runoff generation, and splash-sheet erosion. Overland flow experiments (9 m2) were used to assess the effects of fire-reduced ground cover on concentrated-flow runoff and erosion processes. The study results provide insight regarding fire impacts on runoff, erosion, and soil water repellency in the immediate and

  12. Development of post-fire crown damage mortality thresholds in ponderosa pine

    Treesearch

    James F. Fowler; Carolyn Hull Sieg; Joel McMillin; Kurt K. Allen; Jose F. Negron; Linda L. Wadleigh; John A. Anhold; Ken E. Gibson

    2010-01-01

    Previous research has shown that crown scorch volume and crown consumption volume are the major predictors of post-fire mortality in ponderosa pine. In this study, we use piecewise logistic regression models of crown scorch data from 6633 trees in five wildfires from the Intermountain West to locate a mortality threshold at 88% scorch by volume for trees with no crown...

  13. Tropospheric ozone enhancement during post-harvest crop-residue fires at two downwind sites of the Indo-Gangetic Plain.

    PubMed

    Kumari, Sonal; Verma, Nidhi; Lakhani, Anita; Tiwari, Suresh; Kandikonda, Maharaj Kumari

    2018-05-01

    In the present study, surface ozone (O 3 ), nitrogen oxides (NO x ), and carbon monoxide (CO) levels were measured at two sites downwind of fire active region in the Indo-Gangetic Plain (IGP): Agra (27.16° N, 78.08° E) and Delhi (28.37° N, 77.12° E) to study the impact of post-harvest crop-residue fires. The study period was classified into two groups: Pre-harvest period and Post-harvest period. During the post-harvest period, an enhancement of 17.3 and 31.7 ppb in hourly averaged O 3 mixing ratios was observed at Agra and Delhi, respectively, under similar meteorological conditions. The rate of change of O 3 was also higher in the post-harvest period by 56.2% in Agra and 39.5% in Delhi. Relatively higher O 3 episodic days were observed in the post-harvest period. Fire hotspots detected by Moderate Resolution Imaging Spectroradiometer (MODIS) along with backward air-mass trajectory analysis suggested that the enhanced O 3 and CO levels at the study sites during the post-harvest period could be attributed to crop-residue burning over the North-West IGP (NW-IGP). Satellite observations of surface CO mixing ratios and tropospheric formaldehyde (HCHO) column also showed higher levels during the post-harvest period. Graphical abstract.

  14. Comparison of six fire severity classification methods using Montana and Washington wildland fires

    Treesearch

    Pamela G. Sikkink

    2015-01-01

    Fire severity classifications are used in the post-fire environment to describe fire effects, such as soil alteration or fuel consumption, on the forest floor. Most of the developed classifications are limited because they address very specific fire effects or post-burn characteristics in the burned environment. However, because fire effects vary so much among soil,...

  15. Higher sensitivity and lower specificity in post-fire mortality model validation of 11 western US tree species

    USGS Publications Warehouse

    Kane, Jeffrey M.; van Mantgem, Phillip J.; Lalemand, Laura; Keifer, MaryBeth

    2017-01-01

    Managers require accurate models to predict post-fire tree mortality to plan prescribed fire treatments and examine their effectiveness. Here we assess the performance of a common post-fire tree mortality model with an independent dataset of 11 tree species from 13 National Park Service units in the western USA. Overall model discrimination was generally strong, but performance varied considerably among species and sites. The model tended to have higher sensitivity (proportion of correctly classified dead trees) and lower specificity (proportion of correctly classified live trees) for many species, indicating an overestimation of mortality. Variation in model accuracy (percentage of live and dead trees correctly classified) among species was not related to sample size or percentage observed mortality. However, we observed a positive relationship between specificity and a species-specific bark thickness multiplier, indicating that overestimation was more common in thin-barked species. Accuracy was also quite low for thinner bark classes (<1 cm) for many species, leading to poorer model performance. Our results indicate that a common post-fire mortality model generally performs well across a range of species and sites; however, some thin-barked species and size classes would benefit from further refinement to improve model specificity.

  16. Development of a Test Protocol for Spacecraft Post-Fire Atmospheric Cleanup and Monitoring

    NASA Technical Reports Server (NTRS)

    Zuniga, David; Hornung, Steven D.; Haas, Jon P.; Graf, John C.

    2009-01-01

    Detecting and extinguishing fires, along with post-fire atmospheric cleaning and monitoring, are vital components of a spacecraft fire response system. Preliminary efforts focused on the technology evaluation of these systems under realistic conditions are described in this paper. While the primary objective of testing is to determine a smoke mitigation filter s performance, supplemental evaluations measuring the smoke-filled chamber handheld commercial off-the-shelf (COTS) atmospheric monitoring devices (combustion product monitors) are also conducted. The test chamber consists of a 1.4 cubic meter (50 cu. ft.) volume containing a smoke generator. The fuel used to generate the smoke is a mixture of polymers in quantities representative of materials involved in a circuit board fire as a typical spacecraft fire. Two fire conditions were examined: no flame and flame. No flame events are produced by pyrolyzing the fuel mixture in a quartz tube furnace with forced ventilation to produce a white, lingering-type smoke. Flame events ignite the smoke at the outlet of the tube furnace producing combustion characterized by a less opaque smoke with black soot. Electrochemical sensor measurements showed carbon monoxide is a major indicator of each fire. Acid gas measurements were recorded, but cross interferents are currently uncharacterized. Electrochemical sensor measurements and sample acquisition techniques from photoacoustic sensors are being improved. Overall, this research shows fire characterization using traditional analytical chemistry techniques is required to verify measurements recorded using COTS atmospheric monitoring devices.

  17. Modeling hydrologic and geomorphic hazards across post-fire landscapes using a self-organizing map approach

    USGS Publications Warehouse

    Friedel, Michael J.

    2011-01-01

    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.

  18. A Study of Aircraft Post-Crash Fuel Fire Mitigation

    DTIC Science & Technology

    1994-06-01

    AD-A282. 208 A STUDY OF AIRCRAFT POST-CRASH FUEL FIRE MITIGATION INTERIM REPORT BFLRF No. 292 By D.W. Naegeli B.R. Wright Belvoir Fuels and...DAAK7D-S7-C4.004; WD 36 6. AUTHOR(S) DA7-2C0.W Naegeli D"i N. and Wrigl* Bomnd L sed Zabne, David bi (Zalle. Assoiaes) 7. PERFORMING ORGANIZATION NAME...Proceedings, December 3-5, 1991. 6. Weatherford, W.D., Jr. and Naegeli , D,W., "Study of Pool Burning Self-Extinguishment Mechanisms in Aqueous Diesel

  19. Timing of susceptibility to post-fire debris flows in the western USA

    USGS Publications Warehouse

    DeGraff, Jerome V.; Cannon, Susan H.; Gartner, Joseph E.

    2015-01-01

    Watersheds recently burned by wildfires can have an increased susceptibility to debris flow, although little is known about how long this susceptibility persists, and how it changes over time. We here use a compilation of 75 debris-flow response and fire-ignition dates, vegetation and bedrock class, rainfall regime, and initiation process from throughout the western U.S. to address these issues. The great majority (85 percent) of debris flows occurred within the first 12 months following wildfire, with 71 percent within the first six months. Seven percent of the debris flows occurred between 1 and 1.5 years after a fire, or during the second rainy season to impact an area. Within the first 1.5 years following fires, all but one of the debris flows initiated through runoff-dominated processes, and debris flows occurred in similar proportions in forested and non-forested landscapes. Geologic materials affected how long debris-flow activity persisted, and the timing of debris flows varied within different rainfall regimes. A second, later period of increased debris flow susceptibility between 2.2 and 10 years after fires is indicated by the remaining 8 percent of events, which occurred primarily in forested terrains and initiated largely through landslide processes. The short time period between fire and debris-flow response within the first 1.5 years after ignition, and the longer-term response between 2.2 and 10 years after fire, demonstrate the necessity of both rapid and long-term reactions by land managers and emergency-response agencies to mitigate hazards from debris flows from recently burned areas in the western U.S.

  20. Salvage logging versus the use of burnt wood as a nurse object to promote post-fire tree seedling establishment

    USGS Publications Warehouse

    Castro, J.; Allen, Craig D.; Molina-Morales, M.; Maranon-Jimenez, Sara; Sanchez-Miranda, A.; Zamora, R.

    2011-01-01

    Intense debate surrounds the effects of post-fire salvage logging (SL) versus nonintervention policies on forest regeneration, but scant support is available from experimental studies. We analyze the effect of three post-fire management treatments on the recruitment of a serotinous pine (Pinus pinaster) at a Mediterranean mountain. Treatments were applied 7 months after the fire and differ in the degree of intervention, ranging from “no intervention” (NI, all trees left standing) to “partial cut plus lopping” (PCL, felling most of the trees, cutting the main branches, and leaving all the biomass in situ without mastication), and “SL” (felling and piling the logs, and masticating the woody debris). Seedling survival after 3 years was the highest in PCL (47.3% versus 38.7% in SL). This was associated with the amelioration of microclimatic conditions under the scattered branches, which reduced radiation and soil temperature while increasing soil moisture. Seedling density after 2 years was approximately 5.5 times higher in PCL than in SL, as in SL a large fraction of seedlings was lost as a consequence of mechanized mastication. The NI treatment showed the lowest seedling survival (17.3%). Nevertheless, seedling density was similar to SL. Seedling growth scarcely differed among treatments. Our results show that branches left onsite acted as nurse objects that improved key microclimatic conditions for seedling recruitment. This creates a facilitative interaction ideal for seedling establishment in moisture-deficient ecosystems, as it provides the benefit of a shading overstory but without underground competition.

  1. Patch to landscape patterns in post fire recruitment of a serotinous conifer

    USGS Publications Warehouse

    Ne'eman, Gidi; Fotheringham, C.J.; Keeley, J.E.

    1999-01-01

    Obligate seeding species are highly specialized to fire disturbance and many conifers such as cypress, which are adapted to high intensity stand-replacing fires, have canopy seed banks stored in serotinous cones. Resilience of these trees to fire disturbance is a function of disturbance frequency and one focus of this study was to determine the effect of patch age on postfire recruitment. A second focus was to determine the extent to which fire induced a landscape level change in the location of the forest boundary. Prior to a fire in 1994, a large Cupressus sargentii forest was a mosaic landscape of different aged patches of nearly pure cypress bordered by chaparral. Patches less than 60 years of age were relatively dense with roughly one tree every 1-2 m2 but older patches had thinned to one tree every 3-15 m2. Older trees had substantially greater canopy cone crops but the stand level seed bank size was not significantly correlated with stand age. Fire-dependent obligate seeding species are sensitive to fire return interval because of potential changes in the size of seed banks - facing both a potential 'immaturity risk' and a 'senescence risk'. At our site, C. sargentii regeneration was substantial in stands as young as 20 years, suggesting that fire return interval would need to be shorter than this to pose any significant risk. Reduced seedling recruitment in stands nearly 100 years of age may indicate risk from senescence is greater, however, even the lowest density seedling recruitment was many times greater than the density of mature forests - thus this cypress would appear to be resilient to a wide range of fire return intervals. Changes in landscape patterning of forest and chaparral are unlikely except after fire. Factors that inhibit tree establishment within the shrubland, as well as factors that affect shrub establishment within the forest border likely affect the 'permeability' of this ecotone. After the 1994 fire this boundary appeared to be stable

  2. Long-term post-fire effects on spatial ecology and reproductive output of female Agassiz’s desert tortoises (Gopherus agassizii) at a wind energy facility near Palm Springs, California, USA

    USGS Publications Warehouse

    Lovich, Jeffrey E.; Ennen, Joshua R.; Madrak, Sheila V.; Loughran, Caleb L.; Meyer, Katherin P.; Arundel, Terence R.; Bjurlin, Curtis D.

    2011-01-01

    We studied the long-term response of a cohort of eight female Agassiz’s desert tortoises (Gopherus agassizii) during the first 15 years following a large fire at a wind energy generation facility near Palm Springs, California, USA. The fire burned a significant portion of the study site in 1995. Tortoise activity areas were mapped using minimum convex polygons for a proximate post-fire interval from 1997 to 2000, and a long-term post-fire interval from 2009 to 2010. In addition, we measured the annual reproductive output of eggs each year and monitored the body condition of tortoises over time. One adult female tortoise was killed by the fire and five tortoises bore exposure scars that were not fatal. Despite predictions that tortoises would make the short-distance movements from burned to nearby unburned habitats, most activity areas and their centroids remained in burned areas for the duration of the study. The percentage of activity area burned did not differ significantly between the two monitoring periods. Annual reproductive output and measures of body condition remained statistically similar throughout the monitoring period. Despite changes in plant composition, conditions at this site appeared to be suitable for survival of tortoises following a major fire. High productivity at the site may have buffered tortoises from the adverse impacts of fire if they were not killed outright. Tortoise populations at less productive desert sites may not have adequate resources to sustain normal activity areas, reproductive output, and body conditions following fire.

  3. Predicting Fire Severity and Hydrogeomorphic Effects for Wildland Fire Decision Support

    NASA Astrophysics Data System (ADS)

    Hyde, K.; Woods, S. W.; Calkin, D.; Ryan, K.; Keane, R.

    2007-12-01

    The Wildland Fire Decision Support System (WFDSS) uses the Fire Spread Probability (FSPro) model to predict the spatial extent of fire, and to assess values-at-risk within probable spread zones. This information is used to support Appropriate Management Response (AMR), which involves decision making regarding fire-fighter deployment, fire suppression requirements, and identification of areas where fire may be safely permitted to take its course. Current WFDSS assessments are generally limited to a binary prediction of whether or not a fire will reach a given location and an assessment of the infrastructure which may be damaged or destroyed by fire. However, an emerging challenge is to expand the capabilities of WFDSS so that it also estimates the probable fire severity, and hence the effect on soil, vegetation and on hydrologic and geomorphic processes such as runoff and soil erosion. We present a conceptual framework within which derivatives of predictive fire modelling are used to predict impacts upon vegetation and soil, from which fire severity and probable post-fire watershed response can be inferred, before a fire actually occurs. Fire severity predictions are validated using Burned Area Reflectance Classification imagery. Recent tests indicate that satellite derived BARC images are a simple and effective means to predict post-fire erosion response based on relative vegetation disturbance. A fire severity prediction which reasonably approximates a BARC image may therefore be used to assess post-fire erosion and flood potential before fire reaches an area. This information may provide a new avenue of reliable support for fire management decisions.

  4. Increasing microbial diversity and nitrogen cycling potential of burnt forest soil in Spain through post-fire management

    NASA Astrophysics Data System (ADS)

    Pereg, Lily; Mataix-Solera, Jorge; McMillan, Mary; García-Orenes, Fuensanta

    2016-04-01

    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.

  5. RAPID POST-FIRE HYDROLOGIC WATERSHED ASSESSMENT USING THE AGWA GIS-BASED HYDROLOGIC MODELING TOOL

    EPA Science Inventory

    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...

  6. An 800-year fire history

    Treesearch

    Stanley G. Kitchen

    2010-01-01

    "Fire in the woods!" The words are a real heart stopper. Yet in spite of its capacity to destroy, fire plays an essential role in shaping plant communities. Knowledge of the patterns of fire over long time periods is critical for understanding this role. Trees often retain evidence of nonlethal fires in the form of injuries or scars in the annual growth rings...

  7. Experimental validation of finite element model analysis of a steel frame in simulated post-earthquake fire environments

    NASA Astrophysics Data System (ADS)

    Huang, Ying; Bevans, W. J.; Xiao, Hai; Zhou, Zhi; Chen, Genda

    2012-04-01

    During or after an earthquake event, building system often experiences large strains due to shaking effects as observed during recent earthquakes, causing permanent inelastic deformation. In addition to the inelastic deformation induced by the earthquake effect, the post-earthquake fires associated with short fuse of electrical systems and leakage of gas devices can further strain the already damaged structures during the earthquakes, potentially leading to a progressive collapse of buildings. Under these harsh environments, measurements on the involved building by various sensors could only provide limited structural health information. Finite element model analysis, on the other hand, if validated by predesigned experiments, can provide detail structural behavior information of the entire structures. In this paper, a temperature dependent nonlinear 3-D finite element model (FEM) of a one-story steel frame is set up by ABAQUS based on the cited material property of steel from EN 1993-1.2 and AISC manuals. The FEM is validated by testing the modeled steel frame in simulated post-earthquake environments. Comparisons between the FEM analysis and the experimental results show that the FEM predicts the structural behavior of the steel frame in post-earthquake fire conditions reasonably. With experimental validations, the FEM analysis of critical structures could be continuously predicted for structures in these harsh environments for a better assistant to fire fighters in their rescue efforts and save fire victims.

  8. Foliar stable carbon and nitrogen isotopes in woody Mediterranean species with different life form and post-fire regeneration.

    PubMed

    Saura-Mas, S; Lloret, F

    2010-01-01

    Wildfire is an important ecological disturbance factor in most Mediterranean ecosystems. In the Mediterranean Basin, most shrub species can regenerate after fire by resprouting or seeding. Here, we hypothesize that post-fire regenerative syndromes may potentially co-vary with traits directly related to functional properties involved in resource use. Thus, seeders with a shorter life span and smaller size would have lower water-use efficiency (WUE) than re-sprouting species and would take up nutrients such as nitrogen from more superficial parts of the soil. To test this hypothesis, we compared leaf (13)C and (15)N signatures from 29 co-existing species with different post-fire regeneration strategies. We also considered life form as an additional explanatory variable of the differences between post-fire regenerative groups. Our data support the hypothesis that seeder species (which mostly evolved in the Quaternary under a Mediterranean climate) have lower WUE and less stomatal control than non-seeders (many of which evolved under different climatic conditions in the Tertiary) and consequently greater consumption of water per unit biomass. This would be related to their smaller life forms, which tend to have lower WUE and shorter life and leaf lifespan. Differences in (15)N also support the hypothesis that resprouters have deeper root systems than non-resprouters. The study supports the hypothesis of an overlap between plant functional traits and plant attributes describing post-disturbance resilience.

  9. Rapid-response tools and datasets for post-fire remediation: Linking remote sensing and process-based hydrological models

    Treesearch

    M. E. Miller; William Elliot; M. Billmire; Pete Robichaud; K. A. Endsley

    2016-01-01

    Post-wildfire flooding and erosion can threaten lives, property and natural resources. Increased peak flows and sediment delivery due to the loss of surface vegetation cover and fire-induced changes in soil properties are of great concern to public safety. Burn severity maps derived from remote sensing data reflect fire-induced changes in vegetative cover and soil...

  10. Understanding the drivers of post-fire albedo and radiative forcing across Alaska and Canada: implications for management.

    NASA Astrophysics Data System (ADS)

    Potter, S.; Solvik, K.; Erb, A.; Goetz, S. J.; Johnstone, J. F.; Mack, M. C.; Randerson, J. T.; Roman, M. O.; Schaaf, C. L.; Turetsky, M. R.; Veraverbeke, S.; Wang, Z.; Rogers, B. M.

    2017-12-01

    Boreal forest dynamics including succession, composition, carbon cycling, and surface-atmosphere energy exchanges are largely driven by fire. In Alaska and Canada, burned area and fire frequency have increased since the 1970s, and are projected to continue increasing into the 21st century. In contrast to other biomes, alterations to surface albedo from fires in North American boreal forests are one of the primary feedbacks to climate. Understanding how altered fire regimes impact vegetation composition and energy budgets is therefore critical to forecasting regional and global climate change. High-severity fires cause winter and spring albedo to increase due to increased snow exposure and replacement of evergreen conifers by deciduous broadleaf trees. Although summer albedo decreases initially due to the deposition of black carbon and charred surfaces, it typically increases for several decades thereafter when younger and brighter deciduous trees dominate. The net effect of these albedo changes is expected to result in substantive radiative cooling, but there has been little research to examine how albedo trajectories differ spatially and temporally as a result of differences in burn severity, species composition, topography, climate and soil properties, and what the associated implications for future energy balances are. Here we investigate drivers of post-fire monthly albedo trajectories across Canada and Alaska using a new Collection V006 500 m MODIS daily blue-sky albedo product and historical fires from the Canadian and Alaskan National Fire Databases. The impacts of varying fuel type, landscape position, soils, climate, and burn severity on monthly albedo trajectories are explored using a Random Forest model. This information is then used to predict long-term monthly albedo and radiative forcing for fires that occurred during the MODIS era (2001-2012). We find that higher severity burns in denser forests and environmental conditions that promote either

  11. Evaluation of post-fire strength of concrete flexural members reinforced with glass fiber reinforced polymer (GFRP) bars

    NASA Astrophysics Data System (ADS)

    Ellis, Devon S.

    Owing to their corrosion resistance and superior strength to weight ratio, there has been, over the past two decades, increased interest in the use of fiber-reinforced polymer (FRP) reinforcing bars in reinforced concrete structural members. The mechanical behavior of FRP reinforcement differs from that of steel reinforcement. For example, FRP reinforcement exhibit a linear stress-strain behavior until the bar ruptures and the strength, stiffness and bond properties of FRP reinforcement are affected more adversely by elevated temperatures. All structures are subject to the risk of damage by fire and fires continue to be a significant cause of damage to structures. Many structures do not collapse after being exposed to fire. The safety of the structure for any future use is dependent on the ability to accurately estimate the post-fire load capacity of the structure. Assuming that the changes, due to fire exposure, in the mechanical behavior of the GFRP reinforcing bar and concrete, and the bond between the reinforcing bar and the concrete are understood, an analytical procedure for estimating the post-fire strength of GFRP reinforced concrete flexural elements can be developed. This thesis investigates the changes in: a) tensile properties and bond of GFRP bars; and b) the flexural behavior of GFRP reinforced concrete beams flexural after being exposed to elevated temperatures up to 400°C and cooled to ambient temperature. To this end, twelve tensile tests, twelve pullout bond tests and ten four-point beam tests were performed. The data from the tests were used to formulate analytical procedures for evaluating the post-fire strength of GFRP reinforced concrete beams. The procedure produced conservative results when compared with the experimental data. In general, the residual tensile strength and modulus of elasticity of GFRP bars decrease as the exposure temperature increases. The loss in properties is however, smaller than that observed by other researchers when

  12. RECOVER - An Automated Burned Area Emergency Response Decision Support System for Post-fire Rehabilitation Management of Savanna Ecosystems in the Western US

    NASA Astrophysics Data System (ADS)

    Weber, K.; Schnase, J. L.; Carroll, M.; Brown, M. E.; Gill, R.; Haskett, G.; Gardner, T.

    2013-12-01

    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

  13. Post-fire mulching for runoff and erosion mitigation; Part II: Effectiveness in reducing runoff and sediment yields from small catchments

    Treesearch

    Peter R. Robichaud; Joseph W. Wagenbrenner; Sarah A. Lewis; Louise E. Ashmun; Robert E. Brown; Peter M. Wohlgemuth

    2013-01-01

    Agricultural straw, hydromulch, and wood shred or wood strand mulches increasingly are being used as post-fire hillslope treatments, but the differences in effectiveness among these mulch treatments are not fully understood. Following the 2002 Hayman fire in central Colorado and the 2003 Cedar fire in southern California, matched catchments were monitored for five to...

  14. New procedure for sampling infiltration to assess post-fire soil water repellency

    Treesearch

    P. R. Robichaud; S. A. Lewis; L. E. Ashmun

    2008-01-01

    The Mini-disk Infiltrometer has been adapted for use as a field test of post-fire infiltration and soil water repellency. Although the Water Drop Penetration Time (WDPT) test is the common field test for soil water repellency, the Mini-disk Infiltrometer (MDI) test takes less time, is less subjective, and provides a relative infiltration rate. For each test, the porous...

  15. Geospatial Data Combined With The Automated Geospatial Watershed Assessment (AGWA) Tool For Rapid Post-Fire Watershed Assessments

    NASA Astrophysics Data System (ADS)

    Goodrich, D. C.; Clifford, T. J.; Guertin, D. P.; Sheppard, B. S.; Barlow, J. E.; Korgaonkar, Y.; Burns, I. S.; Unkrich, C. C.

    2016-12-01

    Wildfires disasters are common throughout the western US. While many feel fire suppression is the largest cost of wildfires, case studies note rehabilitation costs often equal or greatly exceed suppression costs. Using geospatial data sets, and post-fire burn severity products, coupled with the Automated Geospatial Watershed Assessment tool (AGWA - www.tucson.ars.ag.gov/agwa), the Dept. of Interior, Burned Area Emergency Response (BAER) teams can rapidly analyze and identify at-risk areas to target rehabilitation efforts. AGWA employs nationally available geospatial elevation, soils, and land cover data to parameterize the KINEROS2 hydrology and erosion model. A pre-fire watershed simulation can be done prior to BAER deployment using design storms. As soon as the satellite-derived Burned Area Reflectance Classification (BARC) map is obtained, a post-fire watershed simulation using the same storm is conducted. The pre- and post-fire simulations can be spatially differenced in the GIS for rapid identification of high at-risk areas of erosion or flooding. This difference map is used by BAER teams to prioritize field observations and in-turn produce a final burn severity map that is used in AGWA/KINEROS2 simulations to provide report ready results. The 2013 Elk Wildfire Complex that burned over 52,600 ha east of Boise, Idaho provides a tangible example of how BAER experts combined AGWA and geospatial data that resulted in substantial rehabilitation cost savings. The BAER team initially, they identified approximately 6,500 burned ha for rehabilitation. The team then used the AGWA pre- and post-fire watershed simulation results, accessibility constraints, and land slope conditions in an interactive process to locate burned areas that posed the greatest threat to downstream values-at-risk. The group combined the treatable area, field observations, and the spatial results from AGWA to target seed and mulch treatments that most effectively reduced the threats. Using this

  16. Long-term effects of prescribed fire on mixed conifer forest structure in the Sierra Nevada, California

    USGS Publications Warehouse

    van Mantgem, Phillip J.; Stephenson, Nathan L.; Knapp, Eric; Keeley, Jon E.

    2011-01-01

    The capacity of prescribed fire to restore forest conditions is often judged by changes in forest structure within a few years following burning. However, prescribed fire might have longer-term effects on forest structure, potentially changing treatment assessments. We examined annual changes in forest structure in five 1 ha old-growth plots immediately before prescribed fire and up to eight years after fire at Sequoia National Park, California. Fire-induced declines in stem density (67% average decrease at eight years post-fire) were nonlinear, taking up to eight years to reach a presumed asymptote. Declines in live stem biomass were also nonlinear, but smaller in magnitude (32% average decrease at eight years post-fire) as most large trees survived the fires. The preferential survival of large trees following fire resulted in significant shifts in stem diameter distributions. Mortality rates remained significantly above background rates up to six years after the fires. Prescribed fire did not have a large influence on the representation of dominant species. Fire-caused mortality appeared to be spatially random, and therefore did not generally alter heterogeneous tree spatial patterns. Our results suggest that prescribed fire can bring about substantial changes to forest structure in old-growth mixed conifer forests in the Sierra Nevada, but that long-term observations are needed to fully describe some measures of fire effects.

  17. Wildfires effects on soils: water repellency, NIR models and post-fire treatments. My personal view (SSS Division Outstanding ECS Award Lecture)

    NASA Astrophysics Data System (ADS)

    Arcenegui, Victoria

    2017-04-01

    I first was intrigued by fire, because all summers we had some of them in our location, and then I was involve in fire effects on soils. We had, and also have, a lot of question to answer. I am absolutely sure that soil science was my best choice. Soils are amazing, a lot of things are happening in soils. Soils and fire, are my main research topics. I studied the immediately effect of fire on soils, focus on the effect of fire in soil water repellency and aggregate stability. Two physical properties that are crucial to post-fire soil response. I also construct NIR models to know the maximum temperature reached in soils. It is well known that temperature is a key factor affecting soils properties. Then, it is a really important tool to predict the temperature reached in a soil after a wildfire. Currently, I am involve in a project to investigate what are the best post-fire treatments in our soils and how this treatments affects soil properties.

  18. The role of forest fire severity on vegetation recovery after 18 years. Implications for forest management of Quercus suber L. in Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Francos, Marcos; Úbeda, Xavier; Tort, Joan; Panareda, Josep María; Cerdà, Artemio

    2016-10-01

    Wildfires are a widespread phenomenon in Mediterranean environments. Wildfires result in different fire severities, and then in contrasting plant cover and floristic composition. This paper analyses the recovery of the vegetation eighteen years after a wildfire in Catalonia. The Pinus pinaster ssp. forest was affected by three different severities in July 1994, and studied the spring of 1995 and again in 2008. After eighteen years (2012), our research found that burnt sites constitute a dense forest with a broad variety of species, including many young pines, shrubs and herbaceous plants, but that the risk of fire remains very high, due to the large quantity of fuel and the flammability of the species. The management of the post-fire is critical when high severity fires take places, and it is recommended that high-severity fires must be avoided for a sustainable forest management. We recommend that once the timber (Pinus plantations) production is not profitable, Quercus suber L. and Pinus pinaster ssp. forest should be promoted, and pine plantations avoided.

  19. Post-fire rill and gully formation, Schultz Fire 2010, Arizona, USA

    Treesearch

    Daniel G. Neary; Karen A. Koestner; Ann Youberg; Peter E. Koestner

    2012-01-01

    The Schultz Fire burned 6100 ha on the eastern slopes of the San Francisco Peaks in northern Arizona. The fire burned between June 20th and 30th, 2010, across moderate to very steep ponderosa pine and mixed conifer watersheds. About 40% of the fire area was classified as high-severity, mostly on mountain slopes greater than 30% and in places exceeding 100%. The upper...

  20. Post-fire rill and gully formation, Schultz Fire 2010, Arizona, USA

    Treesearch

    Daniel G. Neary; Karen A. Koestner; Ann Youberg; Peter E. Koestner

    2011-01-01

    The Schultz Fire burned 6,100 ha on the eastern slopes of the San Francisco Peaks, a dormant Middle Pliocene to Holocene aged stratovolcano in northern Arizona (Figure 1). The fire burned in the Coconino National Forest between June 20th and 30th, 2010, across moderate to very steep ponderosa pine and mixed conifer watersheds. About 40% of the fire area was classified...

  1. Growth Response From Herbicide, Prescribed Fire, and Fertilizer Treatments in Midrotational Loblolly Pine: Fire-Year Response

    Treesearch

    Mary Michelle Barnett; Sandra Rideout; Brian P. Oswald; Kenneth W. Farrish; Hans M. Williams

    2002-01-01

    This study was initiated to determine growth response resulting from the application of prescribed fire and herbicide, with and without fertilization. In southeast Texas, herbicide, prescribed fire and fertilizer treatments were applied in mid-rotational loblolly pine plantations 1.5 years after thinning. Five replications were established at each of two study sites...

  2. Post-fire debris-flow hazard assessment of the area burned by the 2013 Beaver Creek Fire near Hailey, central Idaho

    USGS Publications Warehouse

    Skinner, Kenneth D.

    2013-01-01

    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

  3. Fire season and intensity affect shrub recruitment in temperate sclerophyllous woodlands.

    PubMed

    Knox, K J E; Clarke, P J

    2006-10-01

    The season in which a fire occurs may regulate plant seedling recruitment because of: (1) the interaction of season and intensity of fire and the temperature requirements for seed release, germination and growth; (2) post-fire rainfall and temperature patterns affecting germination; (3) the interaction of post-fire germination conditions and competition from surrounding vegetation; and (4) the interaction of post-fire germination conditions and seed predators and/or seedling herbivores. This study examined the effects of different fire intensities and fire seasons on the emergence and survival of shrubs representing a range of fire response syndromes from a summer rainfall cool climate region. Replicated experimental burns were conducted in two seasons (spring and autumn) in 2 consecutive years and fuel loads were increased to examine the effects of fire intensity (low intensity and moderate intensity). Post-fire watering treatments partitioned the effects of seasonal temperature from soil moisture. Higher intensity fires resulted in enhanced seedling emergence for hard-seeded species but rarely influenced survival. Spring fires enhanced seedling emergence across all functional groups. Reduced autumn recruitment was related to seasonal temperature inhibiting germination rather than a lack of soil moisture or competition. In Mediterranean-type climate regions, seedling emergence has been related to post-fire rainfall and exposure of seeds to seed predators. We think a similar model may operate in temperate summer rainfall regions where cold-induced dormancy over winter exposes seeds to predators for a longer time and subsequently results in recruitment failure. Our results support the theory that the effect of fire season is more predictable where there are strong seasonal patterns in climate. In this study seasonal temperature rather than rainfall appears to be more influential.

  4. Ecohydrologic Implications and Management of Post-fire Soil Water Repellency in Burned Pinon-Juniper Woodlands

    NASA Astrophysics Data System (ADS)

    Madsen, Matthew; Zvirzdin, Daniel; Fernelius, Kaitlynn; McMillan, Mica; Kostka, Stanley

    2014-05-01

    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

  5. Post-fire changes in sediment transport connectivity from pedon to watershed scale. The Navalón wildfire in Eastern Spain

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Bodí, Merche B.; González, Óscar; Mataix Solera, Jorge; Doerr, Stefan Helmut

    2015-04-01

    Wildfire are present in the Earth System since vegetation was present in the continents (Doerr and Cerdà, 2005; Kaiho et al., 2013). Forest fire cause damage in the soil and the vegetation cover (Guénon et al., 2013). The years after a forest fire there is a sudden increase in the soil erosion rates that contribute to connect the pedon, slope tram, tram and watershed with surface flows that results in high erosion rates (Cerdà and Lasanta, 2005; Lasanta and Cerdà, 2005; Cawson et al., 2012; Pérez Cabello et al., 2012; Prats et al., 2015). Although the research on soil erosion after forest fire was carried out at different scales by different authors, there is not information about soil erosion at different scales at the same research site and during the post fire period. After the forest fire of April 2008 in Navalón, Eastern Spain, the Soil Erosion and Degradation Research Group from the University of Valencia initiated the measurement of the soil losses at pedon scale (microplots of 0.30 m2), at slope tram (silt fences of 1.8 m width), at slope scale (abandoned terraces) and at watershed scale, at the bottom of the valley (abandoned terraces). The results show that there is a reduction in the sediment yield from pedon to watershed scale and that the soil erosion took place in the first year after the fire. Acknowledgements To the "Ministerio de Economía and Competitividad" of Spanish Government for finance the POSTFIRE project (CGL2013- 47862-C2-1-R). The research projects GL2008-02879/BTE, LEDDRA 243857 and PREVENTING AND REMEDIATING DEGRADATION OF SOILS IN EUROPE THROUGH LAND CARE (RECARE)FP7-ENV-2013- supported this research. References Carreiras, M., Ferreira, A.J.D., Valente, S., Fleskens, L., Gonzales-Pelayo, Ó., Rubio, J.L., Stoof, C.R., Coelho, C.O.A., Ferreira, C.S.S., Ritsema, C.J. 2014. Comparative analysis of policies to deal with the wildfire risk. Land Degradation & Development, 25, 92-103. http://dx.doi.org/10.1002/ldr.2274 Cawson, J. G

  6. Predicting the effectiveness of different mulching techniques to reduce post-fire runoff and erosion in Mediterranean pine stands - does cover matter?

    NASA Astrophysics Data System (ADS)

    Vieira, Diana; Nunes, João; Prats, Sergio; Serpa, Dalila; Keizer, Jan

    2016-04-01

    revised MMF model allowed, in fact, accurate predictions of runoff and soil erosion over the first year following hydro-mulch application . The obtained efficiency indices (Nash Sutcliffe Efficiency) of 0.82 and 0.71 for runoff and erosion, respectively, suggested that the revised MMF model could be at the base of a tool to assist decision-making in post-fire forest management. Furthermore, the MMF results obtained for hydro-mulching agreed well with those obtained in a previous study in the region for mulching with forest residues (Vieira et al., 2014). Ongoing work is assessing the possible improvements in model predictions by applying MMF on a seasonal basis and/or taking into account the occurrence of soil water repellency, i.e. using the adjustments of MMF to post-fire conditions as proposed in Vieira et al. (2014) and so far only tested - successfully - for eucalypt plantations in the study region. Vieira DCS, Prats SA, Nunes JP, Shakesby RA, Coelho COA, Keizer JJ (2014) Modelling runoff and erosion, and their mitigation, in burned Portuguese forest using the revised Morgan-Morgan-Finney model. Forest Ecology and Management 314: 150-165

  7. Wetland fire remote sensing research--The Greater Everglades example

    USGS Publications Warehouse

    Jones, John W.

    2012-01-01

    Fire is a major factor in the Everglades ecosystem. For thousands of years, lightning-strike fires from summer thunderstorms have helped create and maintain a dynamic landscape suited both to withstand fire and recover quickly in the wake of frequent fires. Today, managers in the Everglades National Park are implementing controlled burns to promote healthy, sustainable vegetation patterns and ecosystem functions. The U.S. Geological Survey (USGS) is using remote sensing to improve fire-management databases in the Everglades, gain insights into post-fire land-cover dynamics, and develop spatially and temporally explicit fire-scar data for habitat and hydrologic modeling.

  8. Effects of a prescribed fire on oak woodland stand structure

    Treesearch

    Danny L. Fry

    2002-01-01

    Fire damage and tree characteristics of mixed deciduous oak woodlands were recorded after a prescription burn in the summer of 1999 on Mt. Hamilton Range, Santa Clara County, California. Trees were tagged and monitored to determine the effects of fire intensity on damage, recovery and survivorship. Fire-caused mortality was low; 2-year post-burn survey indicates that...

  9. Examination of Post-stroke Alteration in Motor Unit Firing Behavior Using High Density Surface EMG Decomposition

    PubMed Central

    Li, Xiaoyan; Holobar, Aleš; Gazzoni, Marco; Merletti, Roberto; Rymer, William Z.; Zhou, Ping

    2014-01-01

    Recent advances in high density surface electromyogram (EMG) decomposition have made it a feasible task to discriminate single motor unit activity from surface EMG interference patterns, thus providing a noninvasive approach for examination of motor unit control properties. In the current study we applied high density surface EMG recording and decomposition techniques to assess motor unit firing behavior alterations post-stroke. Surface EMG signals were collected using a 64-channel 2-dimensional electrode array from the paretic and contralateral first dorsal interosseous (FDI) muscles of nine hemiparetic stroke subjects at different isometric discrete contraction levels between 2 N to 10 N with a 2 N increment step. Motor unit firing rates were extracted through decomposition of the high density surface EMG signals, and compared between paretic and contralateral muscles. Across the nine tested subjects, paretic FDI muscles showed decreased motor unit firing rates compared with contralateral muscles at different contraction levels. Regression analysis indicated a linear relation between the mean motor unit firing rate and the muscle contraction level for both paretic and contralateral muscles (p < 0.001), with the former demonstrating a lower increment rate (0.32 pulses per second (pps)/N) compared with the latter (0.67 pps/N). The coefficient of variation (CoV, averaged over the contraction levels) of the motor unit firing rates for the paretic muscles (0.21 ± 0.012) was significantly higher than for the contralateral muscles (0.17 ± 0.014) (p < 0.05). This study provides direct evidence of motor unit firing behavior alterations post-stroke using surface EMG, which can be an important factor contributing to hemiparetic muscle weakness. PMID:25389239

  10. Post-fire reproduction of herbs at a savanna-gallery forest boundary in Distrito Federal, Brazil.

    PubMed

    Massi, K G; Eugênio, C U O; Franco, A C

    2017-11-01

    In Cerrado, studies of post-fire vegetation recovery show that some herbaceous species are able to flower shortly after fires. However, these were mainly short-term studies that focused on grasslands and savannas. Little is known about the effects of fire on ground layer of forests that border the savannas in Central Brazil. Thus, an accidental burning gave us the opportunity to describe the reproductive activity of the ground layer vegetation after a fire event along a savanna-forest boundary at the IBGE Ecological Reserve, Brasília, Brazil. During the 16-month of the inventory, we registered 170 herbaceous species flowering or fruiting, of which 52 species (31%) may have been influenced by fire that changed their times of reproduction. In the savanna plots reproduction peaked at the end of the rainy season. Of the total number of reproducing species, 90 species occurred only in the savanna and four in the forest. Five herbs were recorded in the forest, savanna and border environments. Late dry season fire probably lead the majority of herbaceous species to have their reproduction spread throughout the study time.

  11. Post-fire recovery of soil organic matter in a Cambisol from typical Mediterranean forest in Southwestern Spain.

    PubMed

    Jiménez-González, Marco A; De la Rosa, José María; Jiménez-Morillo, Nicasio T; Almendros, Gonzalo; González-Pérez, José Antonio; Knicker, Heike

    2016-12-01

    Wildfire is a recurrent phenomenon in Mediterranean ecosystems and contributes to soil degradation and desertification, which are partially caused by alterations to soil organic matter (SOM). The SOM composition from a Cambisol under a Mediterranean forest affected by a wildfire is studied in detail in order to assess soil health status and better understand of soil recovery after the fire event. The soil was sampled one month and twenty-five months after the wildfire. A nearby unburnt site was taken as control soil. Soil rehabilitation actions involving heavy machinery to remove burnt vegetation were conducted sixteen months after the wildfire. Immediately after fire the SOM increased in topsoil due to inputs from charred vegetation, whereas a decrease was observed in the underlying soil layer. Twenty-five months after fire soil-pH increased in fire-affected topsoil due to the presence of ashes, a decrease in SOM content was recorded for the burnt topsoil and similar trend was observed for the water holding capacity. The pyro-chromatograms of burned soils revealed the formation of additional aromatic compounds. The thermal cracking of long-chain n-alkanes was also detected. Solid-state 13 C NMR spectroscopy supported the increase of aromatic compounds in the fire-affected topsoil due to the accumulation of charcoal, whereas the deeper soil sections were not affected by the fire. Two years later, soil parameters for the unburnt and burnt sites showed comparable values. The reduction of the relative intensity in the aromatic C region of the NMR spectra indicated a decrease in the charcoal content of the topsoil. Due to the negligible slope in the sampling site, the loss of charcoal was explained by the post-fire restoration activity, degradation, leaching of pyrogenic SOM into deeper soil horizons or wind erosion. Our results support that in the Mediterranean region, fire-induced alteration of the SOM is not lasting in the long-term. Copyright © 2016 Elsevier B

  12. Impact of the post fire management in some soil chemical properties. First results.

    NASA Astrophysics Data System (ADS)

    Francos, Marcos; Pereira, Paulo; Alcañiz, Meritxell; Úbeda, Xavi

    2016-04-01

    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

  13. Predicting post-fire hillslope erosion in forest lands of the western United States

    Treesearch

    Mary Ellen Miller; Lee H. MacDonald; Peter R. Robichaud; William J. Elliot

    2011-01-01

    Many forests and their associated water resources are at increasing risk from large and severe wildfires due to high fuel accumulations and climate change. Extensive fuel treatments are being proposed, but it is not clear where such treatments should be focussed. The goals of this project were to: (1) predict potential post-fire erosion rates for forests and shrublands...

  14. Reforestation after the Fountain fire in northern California: an untold success story

    Treesearch

    Jianwei Zhang; Jeff Webster; Robert F. Powers; John Mills

    2008-01-01

    Forest fires have been burning ‘hot’ across the United States and particularly in the West recent years. So, too, will the debate on post-fire management strategies. In this paper, we present a successful reforestation project after a catastrophic fire in 1992. Sixteen years later, most lands are covered with vigorous young forest stands. These regenerated stands have...

  15. Six-year post-fire mortality and health of relict ponderosa pines in the Bob Marshall Wilderness Area, Montana

    Treesearch

    Signe B. Leirfallom; Robert E. Keane

    2011-01-01

    In 2003, lightning-caused fires burned through relict ponderosa pine (Pinus ponderosa) stands in the Bob Marshall Wilderness, Montana, after decades of fire exclusion. Since many trees in these stands had Native American bark-peeling scars, concern arose about the adverse fire effects on this cultural and ecological resource. In 2004, Keane and others (2006) began a...

  16. Quantifying post-fire ponderosa pine snags using GIS techniques on scanned aerial photographs

    NASA Astrophysics Data System (ADS)

    Kent, Kevin

    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

  17. Testing the effectiveness of pine needlecast in reducing post-fire soil erosion using complementary experimental approaches

    NASA Astrophysics Data System (ADS)

    Bento, C. P. M.; Shakesby, R. A.; Walsh, R. P. D.; Ferreira, C. S. S.; Ferreira, A. J. D.; Urbanek, E.

    2012-04-01

    Mediterranean wildfire activity has increased markedly in recent decades, leading to enhanced runoff and erosion. Limiting post-fire on-site soil degradation and off-site flooding and sedimentation, however, often has a low priority because of the high costs of materials and labour needed to implement many recognised techniques (e.g. seeding, hydromulching, installing logs along the contour). However, in pine plantations, the crowns may only be scorched so that after fire the needlecast can form a comparatively dense ground cover. Its post-fire erosion-limiting effectiveness is virtually unknown in the Mediterranean context, despite potentially protecting soil with minimal effort (requiring only a delay to existing salvage logging procedures at most). As part of the DESIRE research programme, this paper presents results from two complementary approaches testing the erosion-limiting effectiveness of needlecast. (1) Near Moinhos, central Portugal, two 8m2 erosion plots were established immediately post-fire in September 2009 on a steep (30°) slope representative of an adjacent burnt Pinus pinaster plantation. Soil erosion was monitored during a 3-month pre-treatment phase. Needles were then applied to one plot at a density (37.7% cover) measured on a post-fire pine plantation. Soil losses from treated and untreated plots were then monitored until April 2011. By taking the percentage increase or decrease in erosion between the two monitoring phases for the untreated control plot as the 'expected' pattern, the erosion-limiting effectiveness of needles applied to the treated plot could then be determined. (2) Six adjacent rectangular 1.23m2 lysimeters were filled with gravel and sand, and capped by 10 cm of topsoil taken from a long unburnt Pinus pinaster plantation. They were set at 15° and left open to natural rainfall. This angle was considered the steepest possible from logistical and soil stability points of view. All lysimeters underwent a phase under bare soil

  18. Surface forcing of non-stand-replacing fires in Siberian larch forests

    NASA Astrophysics Data System (ADS)

    Chen, Dong; Loboda, Tatiana V.

    2018-04-01

    Wildfires are the dominant disturbance agent in the Siberian larch forests. Extensive low- to mediate-intensity non-stand-replacing fires are a notable property of fire regime in these forests. Recent large scale studies of these fires have focused mostly on their impacts on carbon budget; however, their potential impacts on energy budget through post-fire albedo changes have not been considered. This study quantifies the post-fire surface forcing for Siberian larch forests that experienced non-stand-replacing fires between 2001 and 2012 using the full record of MODIS MCD43A3 albedo product and a burned area product developed specifically for the Russian forests. Despite a large variability, the mean effect of non-stand-replacing fires imposed through albedo is a negative forcing which lasts for at least 14 years. However, the magnitude of the forcing is much smaller than that imposed by stand-replacing fires, highlighting the importance of differentiating between the two fire types in the studies involving the fire impacts in the region. The results of this study also show that MODIS-based summer differenced normalized burn ratio (dNBR) provides a reliable metric for differentiating non-stand-replacing from stand-replacing fires with an overall accuracy of 88%, which is of considerable importance for future work on modeling post-fire energy budget and carbon budget in the region.

  19. Predicting watershed post-fire sediment yield with the InVEST sediment retention model: Accuracy and uncertainties

    USGS Publications Warehouse

    Sankey, Joel B.; McVay, Jason C.; Kreitler, Jason R.; Hawbaker, Todd J.; Vaillant, Nicole; Lowe, Scott

    2015-01-01

    Increased sedimentation following wildland fire can negatively impact water supply and water quality. Understanding how changing fire frequency, extent, and location will affect watersheds and the ecosystem services they supply to communities is of great societal importance in the western USA and throughout the world. In this work we assess the utility of the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) Sediment Retention Model to accurately characterize erosion and sedimentation of burned watersheds. InVEST was developed by the Natural Capital Project at Stanford University (Tallis et al., 2014) and is a suite of GIS-based implementations of common process models, engineered for high-end computing to allow the faster simulation of larger landscapes and incorporation into decision-making. The InVEST Sediment Retention Model is based on common soil erosion models (e.g., USLE – Universal Soil Loss Equation) and determines which areas of the landscape contribute the greatest sediment loads to a hydrological network and conversely evaluate the ecosystem service of sediment retention on a watershed basis. In this study, we evaluate the accuracy and uncertainties for InVEST predictions of increased sedimentation after fire, using measured postfire sediment yields available for many watersheds throughout the western USA from an existing, published large database. We show that the model can be parameterized in a relatively simple fashion to predict post-fire sediment yield with accuracy. Our ultimate goal is to use the model to accurately predict variability in post-fire sediment yield at a watershed scale as a function of future wildfire conditions.

  20. Post-fire seeding of great basin native plants using conventional and minimum-till rangeland drills

    USDA-ARS?s Scientific Manuscript database

    Objectives of post-fire seeding in the Great Basin include reestablishment of perennial cover, suppression of exotic annual weeds, and increasingly restoration of diverse plant communities. Non-conventional seeding techniques may be required when seeding mixes of grasses, forbs and shrubs containing...

  1. Improving rangeland seeding success in post-fire water repellent soil using surfactant seed coating technology

    USDA-ARS?s Scientific Manuscript database

    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...

  2. Fire-mediated dieback and compositional cascade in an Amazonian forest.

    PubMed

    Barlow, Jos; Peres, Carlos A

    2008-05-27

    The only fully coupled land-atmosphere global climate model predicts a widespread dieback of Amazonian forest cover through reduced precipitation. Although these predictions are controversial, the structural and compositional resilience of Amazonian forests may also have been overestimated, as current vegetation models fail to consider the potential role of fire in the degradation of forest ecosystems. We examine forest structure and composition in the Arapiuns River basin in the central Brazilian Amazon, evaluating post-fire forest recovery and the consequences of recurrent fires for the patterns of dominance of tree species. We surveyed tree plots in unburned and once-burned forests examined 1, 3 and 9 years after an unprecedented fire event, in twice-burned forests examined 3 and 9 years after fire and in thrice-burned forests examined 5 years after the most recent fire event. The number of trees recorded in unburned primary forest control plots was stable over time. However, in both once- and twice-burned forest plots, there was a marked recruitment into the 10-20cm diameter at breast height tree size classes between 3 and 9 years post-fire. Considering tree assemblage composition 9 years after the first fire contact, we observed (i) a clear pattern of community turnover among small trees and the most abundant shrubs and saplings, and (ii) that species that were common in any of the four burn treatments (unburned, once-, twice- and thrice-burned) were often rare or entirely absent in other burn treatments. We conclude that episodic wildfires can lead to drastic changes in forest structure and composition, with cascading shifts in forest composition following each additional fire event. Finally, we use these results to evaluate the validity of the savannization paradigm.

  3. Delayed conifer tree mortality following fire in California

    Treesearch

    Sharon M. Hood; Sheri L. Smith; Daniel R. Cluck

    2007-01-01

    Fire injury was characterized and survival monitored for 5,246 trees from five wildfires in California that occurred between 1999 and 2002. Logistic regression models for predicting the probability of mortality were developed for incense-cedar, Jeffrey pine, ponderosa pine, red fir and white fir. Two-year post-fire preliminary models were developed for incense-cedar,...

  4. A low-cost method to measure the timing of post-fire flash floods and debris flows relative to rainfall

    USGS Publications Warehouse

    Kean, Jason W.; Staley, Dennis M.; Leeper, Robert J.; Schmidt, Kevin Michael; Gartner, Joseph E.

    2012-01-01

    Data on the specific timing of post-fire flash floods and debris flows are very limited. We describe a method to measure the response times of small burned watersheds to rainfall using a low-cost pressure transducer, which can be installed quickly after a fire. Although the pressure transducer is not designed for sustained sampling at the fast rates ({less than or equal to}2 sec) used at more advanced debris-flow monitoring sites, comparisons with high-data rate stage data show that measured spikes in pressure sampled at 1-min intervals are sufficient to detect the passage of most debris flows and floods. Post-event site visits are used to measure the peak stage and identify flow type based on deposit characteristics. The basin response timescale (tb) to generate flow at each site was determined from an analysis of the cross correlation between time series of flow pressure and 5-min rainfall intensity. This timescale was found to be less than 30 minutes for 40 post-fire floods and 11 post-fire debris flows recorded in 15 southern California watersheds ({less than or equal to} 1.4 km2). Including data from 24 other debris flows recorded at 5 more instrumentally advanced monitoring stations, we find there is not a substantial difference in the median tb for floods and debris flows (11 and 9 minutes, respectively); however, there are slight, statistically significant differences in the trends of flood and debris-flow tb with basin area, which are presumably related to differences in flow speed between floods and debris flows.

  5. Synthesis of current knowledge on post-fire seeding for soil stabilization and invasive species control

    USGS Publications Warehouse

    Beyers, Jan L.; Pyke, David A.; Wirth, Troy

    2015-01-01

    The General Accounting Office has identified a need for better information on the effectiveness of post-fire emergency stabilization and rehabilitation methods used by the U.S. Forest Service and Department of Interior (DOI) agencies. Since reviews were published on treatment effectiveness in the early 2000s, treatment choices have changed and increased monitoring has been done. Greater use of native species has added substantially to burned area emergency response (BAER) treatment costs, for example, but quantitative data on this treatment were scarce in earlier reviews. We synthesized current information on the effectiveness of post-fire seeding for both soil stabilization and for prevention of the spread of invasive species in rangelands. We reviewed published literature (peer-reviewed and “gray”) and agency monitoring reports, as well as compiled and analyzed quantitative data in agency files. Products of this review include a web-accessible database of monitoring reports and published information, a scientific journal paper summarizing findings of scientific studies, an annotated bibliography of peer-reviewed papers, a summary report published as a General Technical Report that will be available online (in progress), and presentations to scientific meetings and BAER/ESR team training sessions and workshops. By combining results from studies done by Forest Service and DOI agency personnel with research studies published since the initial reviews, we presented a comprehensive synthesis of seeding effectiveness knowledge that complements the review of other hillslope treatments published by other researchers. This information will help federal land managers make more cost-effective decisions on post-fire stabilization and rehabilitation treatments.

  6. Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Dvinskaya, Mariya L.; Petrov, Ilya A.; Im, Sergei T.; Ranson, Kenneth J.

    2016-01-01

    Fire history within the northern larch forests of Central Siberia was studied (65+degN). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRIs) were found to be 112 +/- 49 years (based on firescars) and 106 +/- 36 years (based on firescars and tree natality dates). FRIs were increased with latitude increase and observed to be about 80 years at 64N, about 200 years near the Arctic Circle and about 300 years nearby the northern range limit of larch stands (approx.71+degN). Northward FRIs increase correlated with incoming solar radiation (r = -0.95). Post- Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase. Keywords Fire ecology Fire history Fire frequency Siberian wildfires Larch forests Climate change

  7. Effects of post-fire salvage logging and a skid trail treatment on ground cover, soils, and sediment production in the interior western United States

    Treesearch

    Joseph W. Wagenbrenner; Lee H. MacDonald; Robert N. Coats; Peter R. Robichaud; Robert E. Brown

    2015-01-01

    Post-fire salvage logging adds another set of environmental effects to recently burned areas, and previous studies have reported varying impacts on vegetation, soil disturbance, and sediment production with limited data on the underlying processes. Our objectives were to determine how: (1) ground-based post-fire logging affects surface cover, soil water repellency,...

  8. Co-firing coal and biomass blends and their influence on the post-combustion CO2 capture installation

    NASA Astrophysics Data System (ADS)

    Więckol-Ryk, Angelika; Smoliński, Adam

    2017-10-01

    Co-firing of biomass with coal for energy production is a well-known technology and plays an important role in the electricity sector. The post-combustion capture integrated with biomass-fired power plants (Bio-CCS) seems to be a new alternative for reducing greenhouse gas emissions. This study refers to the best known and advanced technology for post-combustion CO2 capture (PCC) based on a chemical absorption in monoethanolamine (MEA). The co-firing of hard coal with four types of biomass was investigated using a laboratory fixed bed reactor system. The comparison of gaseous products emitted from the combustion of coal and different biomass blends were determined using gas chromatography. Research proved that co-firing of biomass in fossil fuel power plants is beneficial for PCC process. It may also reduce the corrosion of CO2 capture installation. The oxygen concentration in the flue gases from hard coal combustion was comparable with the respective value for a fuel blend of biomass content of 20% w/w. It was also noted that an increase in biomass content in a sample from 20 to 40 % w/w increased the concentration of oxygen in the flue gas streams. However, this concentration should not have a significant impact on the rate of amine oxidative degradation.

  9. Effectiveness of two contrasting mulching rates to reduce post-fire soil and organic matter losses

    NASA Astrophysics Data System (ADS)

    Silva, Flavio; Prats, Sergio; Vieira, Diana; Puga, João; Lopes, Rita; Gonzaléz-Pelayo, Oscar; Caetano, Ana; Campos, Isabel; Keizer, Jacob

    2017-04-01

    block design with three blocks. Mulching was applied at a "standard" rate of 8.0 Mg ha-1 as had been done in prior field tests (Prats et al. 2012, 2016a, 2016b) as well as at a reduced rate of 2.6 Mg ha-1. This reduced rate was selected based on the results of laboratory experiments that had been carried out using a 1.00 m × 0.75 m free drainage soil flume under artificial rainfall and run-on (Abrantes et al., 2017). These results suggested that this reduced rate was somewhat less effective as the "standard" rate. The results from the first post-fire year in Semide showed that both the "standard" and the reduced mulching rate were not only highly effective in reducing soil losses (with more than 85 %) but also capable of avoiding erosion rates clearly exceeding the tolerable soil loss threshold of 1 Mg ha-1 y-1 proposed by Verheijen et al. (2009). Soil losses amounted, on average, to 8.0 Mg ha-1 y-1 at the untreated plots as opposed to 1.1 and 0.3 Mg ha-1 y-1 at the plots with low and "standard" mulch application rates, respectively. This difference in effectiveness between the two application rates could be related to their difference in protective mulch cover, which corresponded to 48 and 77 % for the low and the "standard" mulching rate, respectively. References Abrantes J.R.C.B., de Lima J.L.M.P., Prats S.A., Keizer J.J., 2017. Assessing soil water repellency spatial variability using a thermographic technique: an exploratory study using a small-scale laboratory soil flume. Geoderma 287, 98-104 Campos I., Abrantes N., Keizer J.J., Vale C., Pereira P., 2016. Major and trace elements in soils and ashes of eucalypt and pine forest plantations in Portugal following a wildfire. Science of the Total Environment 572: 1363-1376 Ferreira R.V., Serpa D., Cerqueira M.A., Keizer J.J., 2016. Short-time phosphorus losses by overland flow in burnt pine and eucalypt plantations in north-central Portugal: A study at micro-plot scale. Science of the Total Environment 551-552: 631

  10. Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Dvinskaya, Mariya L.; Petrov, Ilya A.; Im, Sergei T.; Ranson, Kenneth J.

    2016-01-01

    Fire history within the northern larch forests of Central Siberia was studied (65 + deg N). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRIs) were found to be 112 ± 49 years (based on fire scars) and 106 ± 36 years (based on fire scars and tree natality dates). FRI were increased with latitude increase and observed to be about 80 years at 64 deg N, about 200 years near the Arctic Circle and about 300 years nearby the northern range limit of larch stands (approximately 71 deg + N). Northward FRI increase correlated with incoming solar radiation (r = -0.95). Post Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase.

  11. Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

    PubMed Central

    Kharuk, Viacheslav I.; Dvinskaya, Mariya L.; Petrov, Ilya A.; Im, Sergei T.; Ranson, Kenneth J.

    2017-01-01

    Fire history within the northern larch forests of Central Siberia was studied (65+°N). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRI) were found to be 112 ± 49 years (based on fire scars) and 106 ± 36 years (based on fire scars and tree natality dates). FRI were increased with latitude increase, and observed to be about 80 years at 64°N, about 200 years near the Arctic Circle, and about 300 years nearby the northern range limit of larch stands (~71°+N). Northward FRI increase correlated with incoming solar radiation (r = − 0.95). Post Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase. PMID:28966554

  12. Prescribed fire effects on runoff, erosion, and soil water repellency on steeply-sloped sagebrush rangeland over a five year period

    USDA-ARS?s Scientific Manuscript database

    Fire is an inherent component of sagebrush steppe rangelands in western North America and can dramatically affect runoff and erosion processes. Post-fire flooding and erosion events pose substantial threats to proximal resources, property, and human life. Yet, prescribed fire can serve as a tool to ...

  13. Biogeochemistry and plant physiological traits interact to reinforce patterns of post-fire dominance in boreal forests

    NASA Astrophysics Data System (ADS)

    Shenoy, A.; Kielland, K.; Johnstone, J. F.

    2011-12-01

    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

  14. Can compost improve Quercus pubescens Willd establishment in a Mediterranean post-fire shrubland?

    PubMed

    Larchevêque, Marie; Montès, Nicolas; Baldy, Virginie; Ballini, Christine

    2008-06-01

    The aim of the study was to evaluate the effects of sewage sludge compost (control, 20 kg m(-2), 40 kg m(-2)) supplied to Quercus pubescens Willd seedlings planted in a post-fire calcareous site in Provence (France). Changes in soil properties, seedling survival, growth and nutrition were monitored 7 months, 1.5 years and 2.5 years after amendment, and possible trace metal contamination of soil and seedlings by compost was also evaluated. Compost improved overall soil fertility by increasing organic matter, cation exchange capacity, total N and exchangeable P, K, Mg and B concentrations, but 40 kg m(-2) induced a more significant and more durable effect than 20 kg m(-2). However, the compost had no effect on seedling survival and growth, but increased foliar P and B concentrations at 40 kg m(-2). No foliar contamination of seedlings by trace metals occurred, although amendment increased exchangeable Cu and Zn concentrations in soil. Compost P and exchangeable Cu and Zn concentrations could induce eutrophication and water pollution, and limit rates that can be applied without environmental hazard.

  15. Long term effects of fire on the carbon balance in boreal forests

    NASA Astrophysics Data System (ADS)

    Berninger, Frank; Köster, Kaja; Pumpanen, Jukka

    2013-04-01

    Fire is the primary process which organizes the physical and biological attributes of the boreal biome and influences energy flows and biogeochemical cycles, particularly the carbon and nitrogen cycle. We established a forest fire chronosequence in the northern boreal forest in Lapland (Värriö Strict Nature Reserve), Finland (67°46' N, 29°35' E) that spans 160 years. Soil organic matter and its turnover were measured in and ex situ, as well as biomass of trees. The fungal biomass was assessed using soil ergosterol contents. The results indicate that fires slow down the turnover of soil organic matter for a period of at least 50 years. The turnover rate in recently burnt sites was only half of the turnover of the old forest site. Decreases in the turnover where still substantial 50 years after fire. The slow recovery of fungal biomass after fires seems to be the cause of the decrease since sites with a higher concentration of fungal biomass in the soils had shorter soil organic matter turnover rates. Increases in stand foliar biomass were less important for the turnover of soil organic matter. We tried to explore the potential importance of our finding using a simple data driven simulation model that estimates soil carbon dynamic from litter input and the measured soil carbon turnover times. The results indicate the initial post-fire slowdown of soil carbon turnover is an important component of the boreal carbon cycle. Using our fire intervals the simulated soil carbon stocks with a lower post-fire soil organic matter turnover were up to 15 % larger than simulations assuming a constant carbon turnover rate. Our sensitivity analysis indicates that the effects will be larger in areas with frequent fires. We do not know which environmental factors cause the delay in the turnover time and the effects of fires on post fire soil organic matter turnover could be considerably smaller or larger. Altogether our results fit well to published results from laboratory studies

  16. Temporal evolution of water repellency and preferential flow in the post-fire

    NASA Astrophysics Data System (ADS)

    Alanís, Nancy; Jordán, Antonio; Zavala, Lorena M.

    2015-04-01

    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.

  17. Fire Effects on Microbial Dynamics and C, N, and P Cycling in Larch Forests of the Siberian Arctic

    NASA Astrophysics Data System (ADS)

    Ludwig, S.; Alexander, H. D.; Mann, P. J.; Natali, S.; Schade, J. D.

    2013-12-01

    Arctic forest ecosystems are warming at an accelerated rate relative to lower latitudes, with global implications for C cycling within these regions. As climate continues to warm and dry, wildfire frequency and severity are predicted to increase, creating a positive feedback to climate warming. Because soil microbes regulate carbon (C) and nitrogen (N) cycling between terrestrial ecosystems and the atmosphere, it is important to understand microbial response to fires, particularly in the understudied larch forests in the Siberian Arctic. In this project, we created experimental burn plots in a mature larch forest in the Kolyma River watershed of Northeastern Siberia. Plots were burned at several treatments: control (no burn), low, moderate, and severe. After 1 day, 8 days and 1 year post-fire, we measured CO2 flux from the plots, and measured dissolved organic carbon (DOC), total dissolved nitrogen (TDN), NH4, NO3, PO4, and chromophoric dissolved organic matter (CDOM) from soil leachates. Furthermore, we measured extracellular activity of four enzymes involved in soil C and nutrient cycling (leucine aminopeptidase (LAP), β-glucosidase, phosphatase, and phenol oxidase). Both 1 day and 8 days post-fire DOC, TDN, NH4, and PO4 all increased with burn severity, but by 1 year they were similar to control plots. The aromaticity and molecular weight of DOM decreased with fire severity. One day post-fire we observed a spike in phenol oxidase activity in the severe burns only, and a decline in β-glucosidase and phosphatase activity. By 8 days post-fire all enzyme activities were at the level of the control plots. 1 year post-fire LAP, β-glucosidase, and phosphatase all decreased with fire severity, parallel to a decrease in CO2 flux by fire severity. Ratios of enzymatic activity 1 year post-fire reflect a switch of resource allocation from P acquiring to N acquiring activities in more severe fires. Our results show an immediate microbial response to the short-term effects

  18. Effectiveness of fire-retardant treatments for shingles after 10 years of outdoor weathering

    Treesearch

    S. L. LeVan; C. A. Holmes

    Some building codes require wood shingles to be fire-retardant treated. Because exterior fire-retardant treatments are subjected to weathering, treatment durability and leach resistance are critical for insuring adequate fire protection. We examined the effectiveness of various fire-retardant treatments on wood after 0, 2, 5, and 10 years of outdoor exposure. We used a...

  19. Rainfall simulations on a fire disturbed mediterranean area

    NASA Astrophysics Data System (ADS)

    Rulli, Maria Cristina; Bozzi, Silvia; Spada, Matteo; Bocchiola, Daniele; Rosso, Renzo

    2006-08-01

    SummaryRainfall simulator experiments were carried out in the Liguria region, Italy, immediately after a forest fire in early August, 2003, to evaluate the effects of forest fire on soil hydraulic properties, runoff and erosion. Two adjacent 30 m 2 plots were set up with common physiographic features, and the same fire history, except for the fire of August 2003, which burned only one of them. Since both plots were previously subject to the passage of fire in March 1997, one compares the hydrologic and sedimentologic response of an area burned in year 2003 (B03) with that of an area burnt 6 years before (B97). Each rainfall simulation consisted of a single 60 min application of rainfall with constant intensity of about 76 mm h -1. The results show runoff ratio, evaluated for different pre-event soil moisture conditions, ranging from 0% to 2% for B97 plot, and from 21% to 41% for B03. Runoff ratio for the recently burned plot was 60 times higher than for the plot burned six years before, under wet conditions, and 20 times higher, under very wet conditions. A large increase in sediment production also was measured in B03 plot, as compared with that in B97 plot. Suspended sediment yield from B03 plot was more than two orders of magnitude higher than that from B97 plot in all the simulated events. The high soil losses measured immediately after burning indicate that effective post-fire rehabilitation programs must be carried out to reduce soil erosion in recently burned areas. However, the results for the plot burned six year prior show that recovery of the hydrological properties of the soil occurs after the transient post-fire modification.

  20. Evaluating rehabilitation efforts following the Milford Flat Fire: successes, failures, and controlling factors

    USGS Publications Warehouse

    Duniway, Michael C.; Palmquist, Emily C.; Miller, Mark E.

    2015-01-01

    Uncontrolled wildfire in arid and semiarid ecosystems has become an increasing concern in recent decades. Active rehabilitation of fire-affected areas is often quickly initiated to minimize long-term ecosystem damage. However, the complex soil-geomorphic-vegetation patterns and low and variable moisture conditions in these regions makes restoration challenging. To further inform these post-fire management decisions, we present results from 5 years of vegetation and sediment flux monitoring following the Milford Flat Fire in west-central Utah, USA. Our sampling design includes monitoring plots in areas not burned, areas burned but where no rehabilitation was attempted, and burned areas where various rehabilitation approaches were implemented. At each of the 25 plots, vegetation cover and composition data were collected annually, and wind-driven sediment flux was measured using passive dust traps. To evaluate effectiveness of post-fire rehabilitation treatments in establishing desired species and limiting dominance of undesired species, we analyzed the temporal response of individual species and functional groups as well as community-level multivariate responses. The warm and dry conditions that persisted for approximately 12 months post-treatment, coupled with the surface disturbing rehabilitation approaches used, resulted in near-surface dust fluxes several orders of magnitude higher in treated areas than in unburned or burned areas where no rehabilitation occurred. These dry conditions and high surface sediment flux limited the establishment of seeded species in rehabilitation areas for nearly 3 years. Post-fire rehabilitation did not limit dominance by invasive annual species of concern. Perennial species composition in the areas burned but not subject to post-fire rehabilitation was relatively similar to unburned throughout the study period. In contrast, the burned plots where rehabilitation was attempted were characterized by no (<3%) perennial cover or, in

  1. Climate Impacts of Fire-Induced Land-Surface Changes

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Hao, X.; Qu, J. J.

    2017-12-01

    One of the consequences of wildfires is the changes in land-surface properties such as removal of vegetation. This will change local and regional climate through modifying the land-air heat and water fluxes. This study investigates mechanism by developing and a parameterization of fire-induced land-surface property changes and applying it to modeling of the climate impacts of large wildfires in the United States. Satellite remote sensing was used to quantitatively evaluate the land-surface changes from large fires provided from the Monitoring Trends in Burning Severity (MTBS) dataset. It was found that the changes in land-surface properties induced by fires are very complex, depending on vegetation type and coverage, climate type, season and time after fires. The changes in LAI are remarkable only if the actual values meet a threshold. Large albedo changes occur in winter for fires in cool climate regions. The signs are opposite between the first post-fire year and the following years. Summer day-time temperature increases after fires, while nigh-time temperature changes in various patterns. The changes are larger in forested lands than shrub / grassland lands. In the parameterization scheme, the detected post-fire changes are decomposed into trends using natural exponential functions and fluctuations of periodic variations with the amplitudes also determined by natural exponential functions. The final algorithm is a combination of the trends, periods, and amplitude functions. This scheme is used with Earth system models to simulate the local and regional climate effects of wildfires.

  2. MODIS NDVI Response Following Fires in Siberia

    NASA Technical Reports Server (NTRS)

    Ranson, K. Jon; Sun, G.; Kovacs, K.; Kharuk, V. I.

    2003-01-01

    The Siberian boreal forest is considered a carbon sink but may become an important source of carbon dioxide if climatic warming predictions are correct. The forest is continually changing through various disturbance mechanisms such as insects, logging, mineral exploitation, and especially fires. Patterns of disturbance and forest recovery processes are important factors regulating carbon flux in this area. NASA's Terra MODIS provides useful information for assessing location of fires and post fire changes in forests. MODIS fire (MOD14), and NDVI (MOD13) products were used to examine fire occurrence and post fire variability in vegetation cover as indicated by NDVI. Results were interpreted for various post fire outcomes, such as decreased NDVI after fire, no change in NDVI after fire and positive NDVI change after fire. The fire frequency data were also evaluated in terms of proximity to population centers, and transportation networks.

  3. Prescribed fire as the minimum tool for wilderness forest and fire regime restoration: a case study from the Sierra Nevada, California

    Treesearch

    MaryBeth Keifer; Nathan L. Stephenson; Jeff Manley

    2000-01-01

    Changes in forest structure were monitored in areas treated with prescribed fire in Sequoia and Kings Canyon National Parks. Five years after the initial prescribed fires, tree density was reduced by 61% in the giant sequoia-mixed conifer forest, with the greatest reduction in the smaller trees. This post-burn forest structure falls within the range that may have been...

  4. Summer moisture of forest fire fuels in Oregon and Washington in 1948 and previous years.

    Treesearch

    William G. Morris

    1948-01-01

    The forest fire season of 1948 in Oregon and Washington was regarded by fire suppression agencies as the most favorable for many years. The number of fires started and area burned were, in general, less than for many years. On the national forests the number of fires was the least since 1912 and the acreage burned was the least ever recorded. Was this primarily due to...

  5. Wetland fire scar monitoring and analysis using archival Landsat data for the Everglades

    USGS Publications Warehouse

    Jones, John W.; Hall, Annette E.; Foster, Ann M.; Smith, Thomas J.

    2013-01-01

    The ability to document the frequency, extent, and severity of fires in wetlands, as well as the dynamics of post-fire wetland land cover, informs fire and wetland science, resource management, and ecosystem protection. Available information on Everglades burn history has been based on field data collection methods that evolved through time and differ by land management unit. Our objectives were to (1) design and test broadly applicable and repeatable metrics of not only fire scar delineation but also post-fire land cover dynamics through exhaustive use of the Landsat satellite data archives, and then (2) explore how those metrics relate to various hydrologic and anthropogenic factors that may influence post-fire land cover dynamics. Visual interpretation of every Landsat scene collected over the study region during the study time frame produced a new, detailed database of burn scars greater than 1.6 ha in size in the Water Conservation Areas and post-fire land cover dynamics for Everglades National Park fires greater than 1.6 ha in area. Median burn areas were compared across several landscape units of the Greater Everglades and found to differ as a function of administrative unit and fire history. Some burned areas transitioned to open water, exhibiting water depths and dynamics that support transition mechanisms proposed in the literature. Classification tree techniques showed that time to green-up and return to pre-burn character were largely explained by fire management practices and hydrology. Broadly applicable as they use data from the global, nearly 30-year-old Landsat archive, these methods for documenting wetland burn extent and post-fire land cover change enable cost-effective collection of new data on wetland fire ecology and independent assessment of fire management practice effectiveness.

  6. Assessing fire impacts on the carbon stability of fire-tolerant forests.

    PubMed

    Bennett, Lauren T; Bruce, Matthew J; Machunter, Josephine; Kohout, Michele; Krishnaraj, Saravanan Jangammanaidu; Aponte, Cristina

    2017-12-01

    The carbon stability of fire-tolerant forests is often assumed but less frequently assessed, limiting the potential to anticipate threats to forest carbon posed by predicted increases in forest fire activity. Assessing the carbon stability of fire-tolerant forests requires multi-indicator approaches that recognize the myriad ways that fires influence the carbon balance, including combustion, deposition of pyrogenic material, and tree death, post-fire decomposition, recruitment, and growth. Five years after a large-scale wildfire in southeastern Australia, we assessed the impacts of low- and high-severity wildfire, with and without prescribed fire (≤10 yr before), on carbon stocks in multiple pools, and on carbon stability indicators (carbon stock percentages in live trees and in small trees, and carbon stocks in char and fuels) in fire-tolerant eucalypt forests. Relative to unburned forest, high-severity wildfire decreased short-term (five-year) carbon stability by significantly decreasing live tree carbon stocks and percentage stocks in live standing trees (reflecting elevated tree mortality), by increasing the percentage of live tree carbon in small trees (those vulnerable to the next fire), and by potentially increasing the probability of another fire through increased elevated fine fuel loads. In contrast, low-severity wildfire enhanced carbon stability by having negligible effects on aboveground stocks and indicators, and by significantly increasing carbon stocks in char and, in particular, soils, indicating pyrogenic carbon accumulation. Overall, recent preceding prescribed fire did not markedly influence wildfire effects on short-term carbon stability at stand scales. Despite wide confidence intervals around mean stock differences, indicating uncertainty about the magnitude of fire effects in these natural forests, our assessment highlights the need for active management of carbon assets in fire-tolerant eucalypt forests under contemporary fire regimes

  7. Pre-fire treatments have persistent effects on post-fire plant communities

    Treesearch

    Kristen L. Shive

    2012-01-01

    Wildfires characterized by large areas of high severity are increasingly occurring in ponderosa pine (Pinus ponderosa P. & C. Lawson) forests of the Southwest to extents that are out of the natural range of variability. Managers are now routinely applying thinning and/or burning treatments to reduce fire severity. To investigate the effects of pre-fire treatments...

  8. Fire-protection research for energy technology: Fy 80 year end report

    NASA Astrophysics Data System (ADS)

    Hasegawa, H. K.; Alvares, N. J.; Lipska, A. E.; Ford, H.; Priante, S.; Beason, D. G.

    1981-05-01

    This continuing research program was initiated in order to advance fire protection strategies for Fusion Energy Experiments (FEE). The program expanded to encompass other forms of energy research. Accomplishments for fiscal year 1980 were: finalization of the fault-free analysis of the Shiva fire management system; development of a second-generation, fire-growth analysis using an alternate model and new LLNL combustion dynamics data; improvements of techniques for chemical smoke aerosol analysis; development and test of a simple method to assess the corrosive potential of smoke aerosols; development of an initial aerosol dilution system; completion of primary small-scale tests for measurements of the dynamics of cable fires; finalization of primary survey format for non-LLNL energy technology facilities; and studies of fire dynamics and aerosol production from electrical insulation and computer tape cassettes.

  9. Evaluation of linear spectral unmixing and deltaNBR for predicting post-fire recovery in a North American ponderosa pine forest

    Treesearch

    A. M. S. Smith; L. B. Lenilte; A. T. Hudak; P. Morgan

    2007-01-01

    The Differenced Normalized Burn Ratio (deltaNBR) is widely used to map post-fire effects in North America from multispectral satellite imagery, but has not been rigorously validated across the great diversity in vegetation types. The importance of these maps to fire rehabilitation crews highlights the need for continued assessment of alternative remote sensing...

  10. The potential for LiDAR technology to map fire fuel hazard over large areas of Australian forest.

    PubMed

    Price, Owen F; Gordon, Christopher E

    2016-10-01

    Fuel load is a primary determinant of fire spread in Australian forests. In east Australian forests, litter and canopy fuel loads and hence fire hazard are thought to be highest at and beyond steady-state fuel loads 15-20 years post-fire. Current methods used to predict fuel loads often rely on course-scale vegetation maps and simple time-since-fire relationships which mask fine-scale processes influencing fuel loads. Here we use Light Detecting and Remote Sensing technology (LiDAR) and field surveys to quantify post-fire mid-story and crown canopy fuel accumulation and fire hazard in Dry Sclerophyll Forests of the Sydney Basin (Australia) at fine spatial-scales (20 × 20 m cell resolution). Fuel cover was quantified in three strata important for crown fire propagation (0.5-4 m, 4-15 m, >15 m) over a 144 km(2) area subject to varying fire fuel ages. Our results show that 1) LiDAR provided a precise measurement of fuel cover in each strata and a less precise but still useful predictor of surface fuels, 2) cover varied greatly within a mapped vegetation class of the same fuel age, particularly for elevated fuel, 3) time-since-fire was a poor predictor of fuel cover and crown fire hazard because fuel loads important for crown fire propagation were variable over a range of fire fuel ages between 2 and 38 years post-fire, and 4) fuel loads and fire hazard can be high in the years immediately following fire. Our results show the benefits of spatially and temporally specific in situ fuel sampling methods such as LiDAR, and are widely applicable for fire management actions which aim to decrease human and environmental losses due to wildfire. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Strong Gradients in Forest Sensitivity to Climate Change Revealed by Dynamics of Forest Fire Cycles in the Post Little Ice Age Era

    NASA Astrophysics Data System (ADS)

    Drobyshev, Igor; Bergeron, Yves; Girardin, Martin P.; Gauthier, Sylvie; Ols, Clémentine; Ojal, John

    2017-10-01

    The length of the fire cycle is a critical factor affecting the vegetation cover in boreal and temperate regions. However, its responses to climate change remain poorly understood. We reanalyzed data from earlier studies of forest age structures at the landscape level, in order to map the evolution of regional fire cycles across Eastern North American boreal and temperate forests, following the termination of the Little Ice Age (LIA). We demonstrated a well-defined spatial pattern of post-LIA changes in the length of fire cycles toward lower fire activity during the 1800s and 1900s. The western section of Eastern North America (west of 77°W) experienced a decline in fire activity as early as the first half of the 1800s. By contrast, the eastern section showed these declines as late as the early 1900s. During a regionally fire-prone period of the 1910s-1920s, forests in the western section of Eastern boreal North America burned more than forests in the eastern section. The climate appeared to dominate over vegetation composition and human impacts in shaping the geographical pattern of the post-LIA change in fire activity. Changes in the atmospheric circulation patterns following the termination of the LIA, specifically changes in Arctic Oscillation and the strengthening of the Continental Polar Trough, were likely drivers of the regional fire dynamics.

  12. Depositional characteristics of post-fire flooding following the Schultz Fire, San Francisco Peaks, Arizona

    Treesearch

    Karen A. Koestner; Mike D. Carroll; Daniel G. Neary; Peter E. Koestner; Ann Youberg

    2011-01-01

    During the summer of 2010 the northern Arizona mountain town of Flagstaff experienced three fires all blazing the same week in late-June, the height of the fire season for this region. By July 1st, all three were extinguished, but that was only the first phase of disturbance. The largest and most detrimental of these fires was the Schultz Fire. From June 20th to July...

  13. Isotopic evidence indicates saprotrophy in post-fire Morchella in Oregon and Alaska.

    PubMed

    Hobbie, Erik A; Rice, Samuel F; Weber, Nancy S; Smith, Jane E

    2016-01-01

    We assessed the nutritional strategy of true morels (genus Morchella) collected in 2003 and 2004 in Oregon and Alaska, 1 or 2 y after forest fires. We hypothesized that the patterns of stable isotopes (δ(13)C and δ(15)N) in the sporocarps would match those of saprotrophic fungi and that radiocarbon (Δ(14)C) analyses would indicate that Morchella was assimilating old carbon not current-year photosynthate. We compared radiocarbon and stable isotopes in Morchella with values from concurrently collected foliage, the ectomycorrhizal Geopyxis carbonaria (Alb. & Schwein.) Sacc., the saprotrophic Plicaria endocarpoides (Berk.) Rifai, and with literature to determine isotopic values for ectomycorrhizal or saprotrophic fungi. Geopyxis, Plicaria and Morchella, respectively, were 3‰, 5‰ and 6‰ higher in 13C than foliage and 5‰, 7‰ and 7‰ higher in (15)N. High (15)N enrichment in Morchella indicated that recent litter was not the primary source for Morchella nitrogen, and similar (13)C and (15)N enrichments to Plicaria suggest that Morchella assimilates its carbon and nitrogen from the same source pool as this saprotrophic fungus. From radiocarbon analyses Morchella averaged 11 ± 6 y old (n = 19), Plicaria averaged 17 ± 5 y old (n = 3), foliage averaged 1 ± 2 y old (n = 8) and Geopyxis (n = 1) resembled foliage in Δ(14)C. We conclude that morels fruiting in post-fire environments in our study assimilated old carbon and were saprotrophic. © 2016 by The Mycological Society of America.

  14. Predicting the effectiveness of different mulching techniques in reducing post-fire runoff and erosion at plot scale with the RUSLE, MMF and PESERA models.

    PubMed

    Vieira, D C S; Serpa, D; Nunes, J P C; Prats, S A; Neves, R; Keizer, J J

    2018-08-01

    Wildfires have become a recurrent threat for many Mediterranean forest ecosystems. The characteristics of the Mediterranean climate, with its warm and dry summers and mild and wet winters, make this a region prone to wildfire occurrence as well as to post-fire soil erosion. This threat is expected to be aggravated in the future due to climate change and land management practices and planning. The wide recognition of wildfires as a driver for runoff and erosion in burnt forest areas 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 management operations to mitigate these responses. In this study, the effectiveness of two post-fire treatments (hydromulch and natural pine needle mulch) in reducing post-fire runoff and soil erosion was evaluated against control conditions (i.e. untreated conditions), at different spatial scales. The main objective of this study was to use field data to evaluate the ability of different erosion models: (i) empirical (RUSLE), (ii) semi-empirical (MMF), and (iii) physically-based (PESERA), to predict the hydrological and erosive response as well as the effectiveness of different mulching techniques in fire-affected areas. The results of this study showed that all three models were reasonably able to reproduce the hydrological and erosive processes occurring in burned forest areas. In addition, it was demonstrated that the models can be calibrated at a small spatial scale (0.5 m 2 ) but provide accurate results at greater spatial scales (10 m 2 ). From this work, the RUSLE model seems to be ideal for fast and simple applications (i.e. prioritization of areas-at-risk) mainly due to its simplicity and reduced data requirements. On the other hand, the more complex MMF and PESERA models would be valuable as a base of a possible tool for assessing the risk of water contamination in fire-affected water bodies and

  15. Persistent Effects of Fire Severity on Early Successional Forests in Interior Alaska

    NASA Technical Reports Server (NTRS)

    Shenoy, Aditi; Johnstone, Jill F.; Kasischke, Eric S.; Kielland, Knut

    2011-01-01

    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

  16. Mitigating Hillslope Erosion After Post-fire Salvage Logging Operations

    NASA Astrophysics Data System (ADS)

    Robichaud, P. R.; Bone, E. D.; Brown, R. E.

    2017-12-01

    In the past decades, wildfires around the world have continued to increase in size, severity, and cost. Major concerns after wildfires are the increased runoff and erosion due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. Salvage logging is often a post-fire forest management action to recoup the economic loss of the burned timber, yet concerns arise on the impacts of this activity on water quality. Recently, several studies have been conducted to determine the effect of salvage logging on hillslope erosion. Logging skid trails have been cited as being the cause of high erosion during and after salvage operations. We investigated the impacts of adding operational logging slash to skid trails to reduce hillslope erosion after salvage operations on the 2015 North Star Fire, Washington. We implemented well-designed rapid response approach to compare slash treatment effectiveness by monitoring sediment yield and runoff response from hillslopes with a concentrated flow (rill) experiment. Various runoff amounts are incrementally added to 4 m hillslope plots with and without slash treatments. Our initial results suggest that adding logging slash increased ground cover significantly which contributed to an order of magnitude decrease in hillslope erosion. Integrating erosion mitigation strategies into salvage logging operations should be commonplace when hillslope erosion is a concern.

  17. Recent Arctic tundra fire initiates widespread thermokarst development.

    PubMed

    Jones, Benjamin M; Grosse, Guido; Arp, Christopher D; Miller, Eric; Liu, Lin; Hayes, Daniel J; Larsen, Christopher F

    2015-10-29

    Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burn severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for ~50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions.

  18. Recent Arctic tundra fire initiates widespread thermokarst development

    PubMed Central

    Jones, Benjamin M.; Grosse, Guido; Arp, Christopher D.; Miller, Eric; Liu, Lin; Hayes, Daniel J.; Larsen, Christopher F.

    2015-01-01

    Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burn severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for ~50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions. PMID:26511650

  19. Recent Arctic tundra fire initiates widespread thermokarst development

    DOE PAGES

    Jones, Benjamin M.; Grosse, Guido; Arp, Christopher D.; ...

    2015-10-29

    Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burnmore » severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for -50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions.« less

  20. Recent Arctic tundra fire initiates widespread thermokarst development

    USGS Publications Warehouse

    Jones, Benjamin M.; Grosse, Guido; Arp, Christopher D.; Miller, Eric K.; Liu, Lingli; Hayes, Daniel J.; Larsen, Christopher F.

    2015-01-01

    Fire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burn severity and near-surface, ground-ice content. Subsidence was greatest in severely burned, ice-rich upland terrain (yedoma), accounting for ~50% of the detected subsidence, despite representing only 30% of the fire disturbed study area. Microtopography increased by 340% in this terrain unit as a result of ice wedge degradation. Increases in the frequency, magnitude, and severity of tundra fires will contribute to future thermokarst development and associated landscape change in Arctic tundra regions.

  1. Soil geochemistry controls fire severity: A soil approach to improved understanding of forest fire consequences in southwest Montana.

    NASA Astrophysics Data System (ADS)

    Callahan, R.; Hartshorn, T.

    2014-12-01

    Fire severity can be defined using satellite imagery to ratio mid (~2.2 um) to near (~0.8 um) infrared reflectance values. We examined how lithology and topography affected burn severity, and how post-fire soils data could be used to ground-truth burn severity at two sites in southwestern Montana. A burned area reflectance classification (BARC), lithology, and terrain attributes were used to predict burn severity for the Millie Fire, which was triggered two years ago by lightning and burned ~4,000 ha. Burn severity showed a strong dependence on lithology: the ratio of areas with high burn severity vs. low or moderate burn severities was 2.9 for gneiss (vs. 0.3 for volcanics). The high-severity burn area for the gneiss was larger than the volcanics, despite the latter lithology covering ~270% greater area (~2,600 ha). Aspect and elevation also influenced burn severity with lower severity at higher elevations (2,600-3,000 m) and higher severity at lower elevations (1,800-2,400 m). Southern and western aspects burned more severely than northern and eastern aspects. To clarify whether post-fire soil geochemical changes might predict ground-based estimates of fire severity, a lab experiment was carried out . We expected residual enrichment of trace metal concentrations, as soil organic matter (SOM) was combusted, which we quantified as loss on ignition (LOI). To test this approach, burned and unburned soils were sampled from the ~6000 ha Beartrap 2 fire, which also burned two years. We simulated differing fire severities on unburned soil using a muffle furnace factorially (duration [5, 15, 30, 45, or 60 minutes] x temperature [50, 100, 200, 300, 400, or 500ºC]). Consistent with expectations, unburned samples had a lower mean (±1SD) concentrations for 23 of 30 elements than field-burned samples. For example, barium concentrations ([Ba]) in unburned samples were (708±37μg/g), 16% lower than field-burned [Ba] (841±7 μg/g). Simulated burning yielded smaller [Ba] (732

  2. Topographic Controls on Southern California Ecosystem Function and Post-fire Recovery: a Satellite and Near-surface Remote Sensing Approach

    NASA Astrophysics Data System (ADS)

    Azzari, George

    Southern Californian wildfires can influence climate in a variety of ways, including changes in surface albedo, emission of greenhouse gases and aerosols, and the production of tropospheric ozone. Ecosystem post-fire recovery plays a key role in determining the strength, duration, and relative importance of these climate forcing agents. Southern California's ecosystems vary markedly with topography, creating sharp transitions with elevation, aspect, and slope. Little is known about the ways topography influences ecosystem properties and function, particularly in the context of post-fire recovery. We combined images from the USGS satellite Landsat 5 with flux tower measurements to analyze pre- and post-fire albedo and carbon exchanged by Southern California's ecosystems in the Santa Ana Mountains. We reduced the sources of external variability in Landsat images using several correction methods for topographic and bidirectional effects. We used time series of corrected images to infer the Net Ecosystem Exchange and surface albedo, and calculated the radiative forcing due to CO2 emissions and albedo changes. We analyzed the patterns of recovery and radiative forcing on north- and south-facing slopes, stratified by vegetation classes including grassland, coastal sage scrub, chaparral, and evergreen oak forest. We found that topography strongly influenced post-fire recovery and radiative forcing. Field observations are often limited by the difficulty of collecting ground validation data. Current instrumentation networks do not provide adequate spatial resolution for landscape-level analysis. The deployment of consumer-market technology could reduce the cost of near-surface measurements, allowing the installation of finer-scale instrument networks. We tested the performance of the Microsoft Kinect sensor for measuring vegetation structure. We used Kinect to acquire 3D vegetation point clouds in the field, and used these data to compute plant height, crown diameter, and

  3. Short-term impact of post-fire salvage logging on regeneration, hazardous fuel accumulation, and understorey development in ponderosa pine forest of the Black Hills, SD, USA

    Treesearch

    Tara L Keyser; Fredrick W Smith; Wayne D. Shepperd

    2009-01-01

    We examined the impacts of post-fire salvage logging on regeneration, fuel accumulation, and understorey vegetation and assessed whether the effects of salvage logging differed between stands burned under moderate and high fire severity following the 2000 Jasper Fire in the Black Hills. In unsalvaged sites, fire-related tree mortality...

  4. Moderate drop in water table increases peatland vulnerability to post-fire regime shift

    PubMed Central

    Kettridge, N.; Turetsky, M. R.; Sherwood, J. H.; Thompson, D. K.; Miller, C. A.; Benscoter, B. W.; Flannigan, M. D.; Wotton, B. M.; Waddington, J. M.

    2015-01-01

    Northern and tropical peatlands represent a globally significant carbon reserve accumulated over thousands of years of waterlogged conditions. It is unclear whether moderate drying predicted for northern peatlands will stimulate burning and carbon losses as has occurred in their smaller tropical counterparts where the carbon legacy has been destabilized due to severe drainage and deep peat fires. Capitalizing on a unique long-term experiment, we quantify the post-wildfire recovery of a northern peatland subjected to decadal drainage. We show that the moderate drop in water table position predicted for most northern regions triggers a shift in vegetation composition previously observed within only severely disturbed tropical peatlands. The combined impact of moderate drainage followed by wildfire converted the low productivity, moss-dominated peatland to a non-carbon accumulating shrub-grass ecosystem. This new ecosystem is likely to experience a low intensity, high frequency wildfire regime, which will further deplete the legacy of stored peat carbon. PMID:25623290

  5. Moderate drop in water table increases peatland vulnerability to post-fire regime shift.

    PubMed

    Kettridge, N; Turetsky, M R; Sherwood, J H; Thompson, D K; Miller, C A; Benscoter, B W; Flannigan, M D; Wotton, B M; Waddington, J M

    2015-01-27

    Northern and tropical peatlands represent a globally significant carbon reserve accumulated over thousands of years of waterlogged conditions. It is unclear whether moderate drying predicted for northern peatlands will stimulate burning and carbon losses as has occurred in their smaller tropical counterparts where the carbon legacy has been destabilized due to severe drainage and deep peat fires. Capitalizing on a unique long-term experiment, we quantify the post-wildfire recovery of a northern peatland subjected to decadal drainage. We show that the moderate drop in water table position predicted for most northern regions triggers a shift in vegetation composition previously observed within only severely disturbed tropical peatlands. The combined impact of moderate drainage followed by wildfire converted the low productivity, moss-dominated peatland to a non-carbon accumulating shrub-grass ecosystem. This new ecosystem is likely to experience a low intensity, high frequency wildfire regime, which will further deplete the legacy of stored peat carbon.

  6. Decomposers and the fire cycle in a phryganic (East Mediterranean) ecosystem.

    PubMed

    Arianoutsou-Faraggitaki, M; Margaris, N S

    1982-06-01

    Dehydrogenase activity, cellulose decomposition, nitrification, and CO2 release were measured for 2 years to estimate the effects of a wildfire over a phryganic ecosystem. In decomposers' subsystem we found that fire mainly affected the nitrification process during the whole period, and soil respiration for the second post-fire year, when compared with the control site. Our data suggest that after 3-4 months the activity of microbial decomposers is almost the same at the two sites, suggesting that fire is not a catastrophic event, but a simple perturbation common to Mediterranean-type ecosystems.

  7. Exploring fire dynamics with BFAST approach: case studies in Sardinia, Italy

    NASA Astrophysics Data System (ADS)

    Quarfeld, Jamie; di Mauro, Biagio; Colombo, Roberto; Verbesselt, Jan

    2016-04-01

    The synergistic effect of wildfire and extreme post-fire climatic events, (e.g. droughts or torrential rainfall), may result in long windows of disturbance - challenging the overall resilience of Mediterranean ecosystems and communities. The notion that increased fire frequency and severity may reduce ecosystem resilience has received much attention in Mediterranean regions in recent decades. Careful evaluation of vegetation recovery and landscape regeneration after a fire event provides vital information useful in land management. In this study, an extension of Breaks For Additive Seasonal and Trend (BFAST) is proposed as an ideal approach to monitor change and assess fire dynamics at the landscape level based on analysis of the MODerate-resolution Imaging Spectroradiometer (MODIS, TERRA) time series. To this end, satellite images of three vegetation indices (VIs), the Normalized Burn Ratio (NBR), the Enhanced Vegetation Index (EVI) and the Normalized Difference Vegetation Index (NDVI) were used. The analysis was conducted on areas affected by wildfires in the Sardinia region (Italy) between 2007 and 2010. Some land surface (LS) descriptors (i.e. mean and maximum VI) and fire characteristics (e.g. pre-fire trend & VI, change magnitude, current VI) were extracted to characterize the post-fire evolution of each site within a fifteen-year period (2000-2015). Resilience was estimated using a classic linear function, whereby recovery rates were compared to regional climate data (e.g. water balance) and local landscape components (e.g.topography, land use and land cover). The methodology was applied according to land cover type (e.g. mixed forest, maquis, shrubland, pasture) within each fire site and highlighted the challenge of isolating effects and quantifying the role of fire regime characteristics on resilience in a dynamic way when considering large, heterogeneous areas. Preliminary findings can be outlined as follows: I. NBR showed it was most effective at

  8. Contribution of post-harvest agricultural paddy residue fires in the N.W. Indo-Gangetic Plain to ambient carcinogenic benzenoids, toxic isocyanic acid and carbon monoxide

    NASA Astrophysics Data System (ADS)

    Praphulla Chandra, Boggarapu; Sinha, Vinayak

    2016-04-01

    In the North West Indo-Gangetic Plain (N.W.IGP), large scale post-harvest paddy residue fires occur every year during the months of October-November. This anthropogenic perturbation causes contamination of the atmospheric environment with adverse impacts on regional air quality posing health risks for the population exposed to high concentrations of carcinogens such as benzene and toxic VOCs such as isocyanic acid. These gases and carbon monoxide are known to be emitted from biomass fires along with acetonitrile. Yet no long-term in-situ measurements quantifying the impact of this activity have been carried out in the N.W. IGP. Using high quality continuous online in-situ measurements of these gases at a strategic downwind site over a three year period from 2012 to 2014, we demonstrate the strong impact of this anthropogenic emission activity on ambient concentrations of these gases. In contrast to the pre-paddy harvest period, excellent correlation of benzenoids, isocyanic acid and CO with acetonitrile (a biomass burning chemical tracer); (r ≥ 0.82) and distinct VOC/acetonitrile emission ratios were observed for the post-paddy harvest period which was also characterized by high ambient concentrations of these species. The average concentrations of acetonitrile (1.62 ± 0.18 ppb), benzene (2.51 ± 0.28 ppb), toluene (3.72 ± 0.41 ppb), C8-aromatics (2.88 ± 0.30 ppb), C9-aromatics (1.55 ± 0.19 ppb) and CO (552 ± 113 ppb) in the post-paddy harvest periods were about 1.5 times higher than the annual average concentrations. For isocyanic acid, a compound with both primary and secondary sources, the concentration in the post-paddy harvest period was 0.97 ± 0.17 ppb. The annual average concentrations of benzene, a class A carcinogen, exceeded the annual exposure limit of 1.6 ppb at NTP mandated by the National Ambient Air Quality Standard of India (NAAQS). We show that mitigating the post-harvest paddy residue fires can lower the annual average concentration of

  9. Carbon And Nitrogen Storage Of A Mediterranean-Type Shrubland In Response To Post-Fire Succession And Long-Term Experimental Nitrogen Deposition

    NASA Astrophysics Data System (ADS)

    Vourlitis, G. L.; Hentz, C. S.

    2015-12-01

    Mediterranean-type shublands are subject to periodic fire and high levels of atmospheric nitrogen (N) deposition. Little is known how N inputs interact with post-fire secondary succession to affect ecosystem carbon (C) and N storage and cycling. Thus, a field experiment was conducted in a chaparral stand located in NE San Diego County, USA that burned during a wildfire in July 2003 to test the hypotheses that rates of C and N storage would significantly increase in response to experimental N addition. The experimental layout consists of a randomized design where four-10 x 10 m plots received 5 gN m-2 (added N) in the fall of each year since 2003 and four-10 x 10 m plots served as un-manipulated controls. Aboveground biomass C and N pools and fluxes, including biomass and litter C and N pool size, litter production, net primary production (NPP), N uptake, and litter C and N mineralization were measured seasonally (every 3 months) for a period of 10 years. Belowground surface (0-10 cm) soil extractable N, pH, and total soil N and C pools and surface root biomass C and N pools were also measured seasonally for a period of 10 years, while N losses from leaching were measured over a shorted (8 year) period of time. Added N led to a rapid increase in soil extractable N and a decline in soil pH; however, total soil C and N storage have yet to be affected by N input. Added N plots initially had significantly lower C and N storage than control plots; however, rates of aboveground N and C storage became significantly higher added N plots after 4-5 years of exposure. N losses from leaching continue to be significantly higher in added N plots even with an increase in aboveground C and N storage. The impact of N enrichment on ecosystem C and N storage varied depending on the stage of succession, but the eventual N-induced increase in NPP has implications for fuel buildup and future fire intensity. While N enrichment acted to increase aboveground C and N storage, plots exposed

  10. Fire History of a Forest, Savanna, and Fen Mosaic at White Ranch State Forest

    Treesearch

    Daniel C. Dey; Ricahrd P. Guyette; Michael C. Stambaugh

    2004-01-01

    We present the fire history of a 1-km2 area that is a mosaic of oak forest, savanna, and fen on the White Ranch State Forest, Howell County, Missouri. We dated 135 fire scars on 35 cross-sections of post oak ( Quercus stellata) trees and constructed a fire chronology dating from 1705 to 1997. Mean fire return intervals by periods were 3.7 years (...

  11. Contributions of microbial activity and ash deposition to post-fire nitrogen availability in a pine savanna

    NASA Astrophysics Data System (ADS)

    Ficken, Cari D.; Wright, Justin P.

    2017-01-01

    Many ecosystems experience drastic changes to soil nutrient availability associated with fire, but the magnitude and duration of these changes are highly variable among vegetation and fire types. In pyrogenic pine savannas across the southeastern United States, pulses of soil inorganic nitrogen (N) occur in tandem with ecosystem-scale nutrient losses from prescribed burns. Despite the importance of this management tool for restoring and maintaining fire-dependent plant communities, the contributions of different mechanisms underlying fire-associated changes to soil N availability remain unclear. Pulses of N availability following fire have been hypothesized to occur through (1) changes to microbial cycling rates and (2) direct ash deposition. Here, we document fire-associated changes to N availability across the growing season in a longleaf pine savanna in North Carolina. To differentiate between possible mechanisms driving soil N pulses, we measured net microbial cycling rates and changes to soil δ15N before and after a burn. Our findings refute both proposed mechanisms: we found no evidence for changes in microbial activity, and limited evidence that ash deposition could account for the increase in ammonium availability to more than 5-25 times background levels. Consequently, we propose a third mechanism to explain post-fire patterns of soil N availability, namely that (3) changes to plant sink strength may contribute to ephemeral increases in soil N availability, and encourage future studies to explicitly test this mechanism.

  12. Land Fire impacts assessment on the Rice Watershed, California. 2007

    NASA Astrophysics Data System (ADS)

    Zahraei, A.; Imam, B.; Sorooshian, S.

    2009-12-01

    Burn impacts assessment is a key factor for the post-fire disaster management. For example, assessing wildfire impacts on vegetation is an important component of improving the prediction of hydrologic and ecologic impacts of wildfires within the affected watershed. Many studies have analyzed satellite derived indices of vegetation vigor as indicator of burning effects. This poster reports a study in which Landsat (TM) data was used to compute three indices, NDVI, MASAVI and NBR, which are commonly used in assessing wildfire impacts. The study focused on the Rice watershed southern California, which was affected by a major wildfire in the 2007 fire season. A series of before and after Landsat images were used to evaluate these indices evaluated before and after the wildfire. Comparison between the three indices reveals that the affects of the fire were not very prominently present in the Satellite observation due to the length of time separating the fire from the next available Lansat scene. Such separation may include a period of vegetation recovery. However, when compared with the scenes from the previous year, but for the same season, post fire vegetation show marked differences from pre-fire conditions. The ability of NDVI, MSAVI and NBR to monitor post-fire impacts on vegetation is further evaluated by comparing precipitation patterns in 2006 and 2007, which may shed more light on whether the marked difference in these indices are due to dry/wet differences or to the impacts of fire. NDVI shows more reliability and better representation of both long-term and short-term impacts of wild-fire.

  13. Production and aerial application of wood shreds as a post-fire hillslope erosion mitigation treatment

    Treesearch

    Peter R. Robichaud; Louise E. Ashmun; Randy B. Foltz; Charles G. Showers; J. Scott Groenier; Jennifer Kesler; Claire DeLeo; Mary Moore

    2013-01-01

    Guidelines for the production and aerial application of wood shred mulch as a post-fire hillslope treatment were developed from laboratory and field studies, several field operations, and the evaluations of professionals involved in those operations. At two early trial sites, the wood shred mulch was produced off-site and transported to the area of use. At the 2010...

  14. Can post-fire erosion rates be estimated using a novel plastic optical fibre turbidity sensor?

    NASA Astrophysics Data System (ADS)

    Keizer, Jan Jacob; Bilro, Lúcia; Martins, Martinho M. A.; Machado, Ana Isabel; Karine Boulet, Anne; Vieira, Diana C. S.; Sequeira, Filipa; Prats, Sergio A.; Nogueira, Rogério

    2014-05-01

    It is well-established that wildfires can play an important role in the hydrological and erosion response of forested catchments, substantially increasing overland as well as stream flow and associated sediment yield during the earlier stages of the window-of-disturbance. Even so, it continues a major challenge to quantify post-fire erosion rates and their evolution with time-since-fire, both for plot and catchment outlets. This constraint could to some extent be overcome by low-cost turbidity sensors, placed in runoff collection tanks and at multiple points across stream flow sections. Plastic optical fibre turbidity sensors (POF) have, in that respect, much potential, due to their reduced costs, suitability for multiplexing and robustness under adverse monitoring conditions. The present study explores this potential for recently burnt areas, where the characteristics of the transported sediments can be expected to change markedly over time due to exhaustion of ashes. To this end, a large number of plot- and catchment-scale runoff samples were studied that had been collected in the course of 1- to 2-weekly field monitoring of a recently burnt study area in north-central Portugal. Comparison of the sediment and organic matter contents of these samples with turbidity readings obtained with a novel POF sensor suggested that the POF sensor would greatly facilitate obtaining rough estimates of post-fire erosion rates but would not dispense of regular calibration under changing sediment load characteristics.

  15. Post-wildfire physiological ecology of an Australian microbat.

    PubMed

    Doty, Anna C; Stawski, Clare; Law, Brad S; Geiser, Fritz

    2016-10-01

    Historical patterns of wildfires are being altered as a result of changing climate and therefore are becoming an increasingly pressing global issue. How small mammals deal physiologically with changes in landscape and food availability due to fire remains largely unknown, although recent studies on small heterothermic terrestrial mammals have shown an increase in post-fire torpor use to reduce energy and foraging requirements. However, data on the behavioural and physiological responses of bats after fires are scarce, although potentially these volant species may differ from terrestrial mammals. Therefore, we investigated the post-fire thermal biology and activity of lesser long-eared bats (Nyctophilus geoffroyi) using temperature-telemetry in Warrumbungle National Park, NSW, which experienced a devastating wildfire in 2013. The study comprised two field seasons, one in 2013 within 4 months after the fire, and one in 2015 two years after the fire to identify potential changes in behaviour and physiology. Interestingly, soon after the fire, bats showed significantly shorter torpor bout duration (11.8 ± 12.5 h) and longer normothermia duration (8.7 ± 4.6 h) in comparison to those in 2015 (torpor bout duration: 24.1 ± 23.5 h; normothermia duration: 2.5 ± 1.5 h). Insect availability was significantly (20-fold) higher in 2013 than in 2015, which was likely an important factor resulting in the short average torpor bout duration by N. geoffroyi after the fire. Our data indicate that volant bats appear to show the opposite post-fire behavioural and physiological responses to small terrestrial mammals, showing longer normothermic and active periods and shorter torpor bouts to capitalise on an increase in available post-fire resources.

  16. Reduced frequency and severity of residential fires following delivery of fire prevention education by on-duty fire fighters: cluster randomized controlled study.

    PubMed

    Clare, Joseph; Garis, Len; Plecas, Darryl; Jennings, Charles

    2012-04-01

    In 2008, Surrey Fire Services, British Columbia, commenced a firefighter-delivered, door-to-door fire-prevention education and smoke alarm examination/installation initiative with the intention of reducing the frequency and severity of residential structure fires in the City of Surrey. High-risk zones within the city were identified and 18,473 home visits were undertaken across seven temporal delivery cohorts (13.8% of non-apartment dwellings in the city). The frequency and severity of fires pre- and post- the home visit intervention was examined in comparison to randomized high-risk cluster controls. Overall, the frequency of fires was found to have reduced in the city overall, however, the reduction in the intervention cohorts was significantly larger than for controls. Furthermore, when fires did occur within the intervention cohorts, smoke detectors were activated more frequently and the fires were confined to the object of origin more often post-home visits. No equivalent pattern was observed for the cluster control. On-duty fire fighters can reduce the frequency and severity of residential fires through targeted, door-to-door distribution of fire prevention education in high-risk areas. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Chapter 9 - Monitoring survival of fire-injured trees in Oregon and Washington (Project WC-F-08-03)

    Treesearch

    Robert A. Progar; Lisa Ganio; Lindsay Grayson; Sharon M. Hood

    2018-01-01

    Wild and prescribed fire injury to trees can produce mortality that is not immediately apparent, and environmental stress subsequent to a fire may also contribute to tree mortality in the years after a fire (Hood and Bentz 2007). In order to predict post-fire tree mortality from fire injury variables before tree mortality is clearly apparent, dozens of statistical...

  18. Fire-induced changes in boreal forest canopy volume and soil organic matter from multi-temporal airborne lidar

    NASA Astrophysics Data System (ADS)

    Alonzo, M.; Cook, B.; Andersen, H. E.; Babcock, C. R.; Morton, D. C.

    2016-12-01

    Fire in boreal forests initiates a cascade of biogeochemical and biophysical processes. Over typical fire return intervals, net radiative forcing from boreal forest fires depends on the offsetting impacts of greenhouse gas emissions and post-fire changes in land surface albedo. Whether boreal forest fires warm or cool the climate over these multi-decadal intervals depends on the magnitude of fire emissions and the time scales of decomposition, albedo changes, and forest regrowth. Our understanding of vegetation and surface organic matter (SOM) changes from boreal forest fires is shaped by field measurements and moderate resolution remote sensing data. Intensive field plot measurements offer detailed data on overstory, understory, and SOM changes from fire, but sparse plot data can be difficult to extend across the heterogeneous boreal forest landscape. Conversely, satellite measurements of burn severity are spatially extensive but only provide proxy measures of fire effects. In this research, we seek to bridge the scale gap between existing intensive and extensive methods using a combination of airborne lidar data and time series of Landsat data to evaluate pre- and post-fire conditions across Alaska's Kenai Peninsula. Lidar-based estimates of pre-fire stand structure and composition were essential to characterize the loss of canopy volume from fires between 2001 and 2014, quantify transitions from live to dead standing carbon pools, and isolate vegetation recovery following fire over 1 to 13 year time scales. Results from this study demonstrate the utility of lidar for estimating pre-fire structure and species composition at the scale of individual tree crowns. Multi-temporal airborne lidar data also provide essential insights regarding the heterogeneity of canopy and SOM losses at a sub-Landsat pixel scale. Fire effects are forest-structure and species dependent with variable temporal lags in carbon release due to delayed mortality (>5 years post fire) and

  19. Mapping burn severity, pine beetle infestation, and their interaction at the High Park Fire

    NASA Astrophysics Data System (ADS)

    Stone, Brandon

    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

  20. Contribution of post-harvest agricultural paddy residue fires in the N.W. Indo-Gangetic Plain to ambient carcinogenic benzenoids, toxic isocyanic acid and carbon monoxide.

    PubMed

    Chandra, B P; Sinha, Vinayak

    2016-03-01

    In the north west Indo-Gangetic Plain (N.W.IGP), large scale post-harvest paddy residue fires occur every year during the months of October-November. This anthropogenic perturbation causes contamination of the atmospheric environment with adverse impacts on regional air quality posing health risks for the population exposed to high concentrations of carcinogens such as benzene and toxic VOCs such as isocyanic acid. These gases and carbon monoxide are known to be emitted from biomass fires along with acetonitrile. Yet no long-term in-situ measurements quantifying the impact of this activity have been carried out in the N.W. IGP. Using high quality continuous online in-situ measurements of these gases at a strategic downwind site over a three year period from 2012 to 2014, we demonstrate the strong impact of this anthropogenic emission activity on ambient concentrations of these gases. In contrast to the pre-paddy harvest period, excellent correlation of benzenoids, isocyanic acid and CO with acetonitrile (a biomass burning chemical tracer); (r≥0.82) and distinct VOC/acetonitrile emission ratios were observed for the post-paddy harvest period which was also characterized by high ambient concentrations of these species. The average concentrations of acetonitrile (1.62±0.18ppb), benzene (2.51±0.28ppb), toluene (3.72±0.41ppb), C8-aromatics (2.88±0.30ppb), C9-aromatics (1.55±0.19ppb) and CO (552±113ppb) in the post-paddy harvest periods were about 1.5 times higher than the annual average concentrations. For isocyanic acid, a compound with both primary and secondary sources, the concentration in the post-paddy harvest period was 0.97±0.17ppb. The annual average concentrations of benzene, a class A carcinogen, exceeded the annual exposure limit of 1.6ppb at NTP mandated by the National Ambient Air Quality Standard of India (NAAQS). We show that mitigating the post-harvest paddy residue fires can lower the annual average concentration of benzene and ensure

  1. Burn Severity Based Stream Buffers for Post Wildfire Salvage Logging Erosion

    NASA Astrophysics Data System (ADS)

    Bone, E. D.; Robichaud, P. R.; Brooks, E. S.; Brown, R. E.

    2017-12-01

    Riparian buffers may be managed for timber harvest disturbances to decrease the risk of hillslope erosion entering stream channels during runoff events. After a wildfire, burned riparian buffers may become less efficient at infiltrating runoff and reducing sedimentation, requiring wider dimensions. Testing riparian buffers under post-wildfire conditions may provide managers guidance on how to manage post-fire salvage logging operations on hillslopes and protect water quality in adjacent streams. We tested burned, unlogged hillslopes at the 2015 North Star Fire and 2016 Cayuse Mountain Fire locations in Washington, USA for their ability to reduce runoff flows and sedimentation. Our objectives were to: 1) measure the travel distances of concentrated flows using three sediment-laden flow rates, 2) measure the change in sediment concentration as each flow moves downslope, 3) test hillslopes under high burn-severity, low burn-severity and unburned conditions, and 4) conduct experiments at 0, 1 and 2 years since the fire events. Mean total flow length at the North Star Fire in year 1 was 211% greater at low burn-severity sites than unburned sites, and 467% greater at high burn-severity sites than unburned sites. Results decreased for all burned sites in year 2; by 40% at the high burn-severity sites, and by 30% at the low burn-severity sites, with no significant changes at the unburned sites. We tested only high burn-severity sites at the Cayuse Mountain Fire in year 0 and 1 where the mean total flow length between year 0 and year 1 decreased by 65%. The results of sediment concentration changes tracked closely with the magnitude of changes in flow travel lengths between treatments. Results indicate that managers may need to increase the widths of burned stream buffers during post-wildfire salvage logging for water quality protection, but stream buffer widths may decrease with less severe burn severity and increasing elapsed time (years) since fire.

  2. Responses in bird communities to wildland fires in southern California

    USGS Publications Warehouse

    Mendelsohn, Mark B.; Brehme, Cheryl S.; Rochester, Carlton J.; Stokes, Drew C.; Hathaway, Stacie A.; Fisher, Robert N.

    2008-01-01

    There is a growing body of literature covering the responses of bird species to wildland fire events. Our study was unique among these because we investigated the effects of large-scale wildland fires on entire bird communities across multiple vegetation types. We conducted avian point counts during the breeding seasons for two years before and two years after the Cedar and Otay Fires in 2003 in southern California. Our balanced sampling effort took place at two sites, one low-elevation and one high-elevation, each containing replicate stations (burned and unburned) within five vegetation types: chaparral, coastal sage scrub, grassland, oak woodland, and riparian. Although fire caused some degree of change in the vegetation structure at all of our impacted survey points, we found that the post-fire shrub and tree cover was significantly lower in only two of the vegetation types within the low-elevation site, coastal sage scrub and chaparral. We found no significant changes in cover at the high-elevation site. Using univariate and multivariate analyses, we tested whether the fires were associated with a change in bird species diversity, community structure, and the relative abundance of individuals within a species. We found that species diversity changed in only one circumstance: it increased in coastal sage scrub at the low-elevation site. Multivariate analyses revealed significant differences in the post-fire bird community structure in the low-elevation chaparral, low-elevation coastal sage scrub, and the high-elevation grassland communities. Vegetation characteristics altered by fire, such as decreases in shrub and tree cover, influenced the changes we observed in the bird communities. The relative abundance of some species (lazuli bunting [Passerina amoena] and horned lark [Eremophila alpestris]) significantly increased after the fires, while other species declined significantly (Anna's hummingbird [Calypte anna], wrentit [Chamaea fasciata], and bushtit

  3. Three years of hillslope sediment yields following the Valley Complex fires, western Montana

    Treesearch

    Peter R. Robichaud; Joseph W. Wagenbrenner; Robert E. Brown; Kevin M. Spigel

    2009-01-01

    The 2000 Bitterroot Valley wildfires provided an opportunity to measure post-fire effects and recovery rates. We established 24 small (0.01 ha [0.02 acre]) plots in four high-severity burn sites. We measured sediment yields at each site with silt fences. We also measured rainfall characteristics, soil water repellency, vegetative cover, and other site characteristics....

  4. Post-fire soil nutrient redistribution in northern Chihuahuan Desert

    NASA Astrophysics Data System (ADS)

    Wang, G.; Li, J. J.; Ravi, S.; Sankey, J. B.; Duke, D.; Gonzales, H. B.; Van Pelt, S.

    2016-12-01

    The desert grassland in the southwestern US has undergone dramatic land degradation with woody shrub encroachment over the last 150 years. Wind erosion and periodic fires are major drivers of vegetation dynamics in these ecosystems. Due to climate change and anthropogenic disturbances, many drylands are undergoing changes in fire regimes, which can largely alter the nutrient loss rate as well as the soil resource heterogeneity. In this study, we used manipulative field experiments, laboratory and geostatistical analyses to investigate the distribution of fertile islands, nutrient loss rate and spatial variation. Replicated burned and control experimental plots were set up in a desert grassland in northern Chihuahuan Desert in March 2016. Windblown sediments were monitored by multiple MWAC sediment collectors on each plot. Surface soil samples, with their locations accurately recorded (i.e., under shrub, under grass, and bare interspace) were collected twice per year in spring and again in summer after the experimental setup. Our preliminary results show that the spatial heterogeneity of soil C and N in the burned plots has changed notably compared to the control plots. Our results further demonstrated that areas with burned shrubs is most vulnerable to wind erosion, therefore the soil nutrient loss is most significant, almost five times of the nutrient loss rate of bare areas. Interspace bare areas is in the lowest micro-land and some of the surface has caliche, which makes the surface resistant to wind erosion. And areas with burned grass receive the lightest wind erosion and nutrient loss, around one third of the erosion on bare areas, because burned grasses still cover the surface and the dead bodies can eliminate wind erosion to a large extent. Hence, periodic fire in desert grassland favors the evenness distribution of soil nutrients and can retard the shrub encroachment process.

  5. Fire and Deforestation Dynamics in South America over the Past 50 Years

    NASA Astrophysics Data System (ADS)

    van Marle, M.; Field, R. D.; van der Werf, G.

    2015-12-01

    Fires play an important role in the Earth system and are one of the major sources of greenhouse gases and aerosols. Satellites have been key to understand their spatial and temporal variability in space and time, but the most frequently used satellite datasets start only in 1995. There are still large uncertainties about the frequency and intensity of fires in the pre-satellite time period, especially in regions with active deforestation, which may have changed dramatically in intensity in the past decades influencing fire dynamics. We used two datasets to extend the record of fires and deforestation in the Amazon region back in time: 1) annual forest loss rates starting in 1990 derived from Vegetation Optical Depth (VOD), which is a satellite-based vegetation product that can be used as proxy for forest loss, and 2) horizontal visibility as proxy for fire emissions, reported by weather stations and airports in the Amazon, which started around 1940, and having widespread coverage since 1973. We show that these datasets overlap with fire emission estimates from the Global Fire Emissions Database (GFED) enabling us to estimate fire emissions over the last 50 years. We will discuss how fires have varied over time in this region with globally significant emissions, how droughts have influenced fire activity and deforestation rates, and what the impact is of land-use change caused by fire on emissions in the Amazon region.

  6. Early spring post-fire snow albedo dynamics in high latitude boreal forests using Landsat-8 OLI data

    PubMed Central

    Wang, Zhuosen; Erb, Angela M.; Schaaf, Crystal B.; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A.; Román, Miguel O.

    2018-01-01

    Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (< 100m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high- burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will thus

  7. Early Spring Post-Fire Snow Albedo Dynamics in High Latitude Boreal Forests Using Landsat-8 OLI Data

    NASA Technical Reports Server (NTRS)

    Wang, Zhuosen; Erb, Angela M.; Schaaf, Crystal B.; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A.; Roman, Miguel O.

    2016-01-01

    Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (less than 100 m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high-burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500 m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will

  8. Early spring post-fire snow albedo dynamics in high latitude boreal forests using Landsat-8 OLI data.

    PubMed

    Wang, Zhuosen; Erb, Angela M; Schaaf, Crystal B; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A; Román, Miguel O

    2016-11-01

    Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (< 100m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high- burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will thus

  9. Strategies for preventing invasive plant outbreaks after prescribed fire in ponderosa pine forest

    USGS Publications Warehouse

    Symstad, Amy J.; Newton, Wesley E.; Swanson, Daniel J.

    2014-01-01

    Land managers use prescribed fire to return a vital process to fire-adapted ecosystems, restore forest structure from a state altered by long-term fire suppression, and reduce wildfire intensity. However, fire often produces favorable conditions for invasive plant species, particularly if it is intense enough to reveal bare mineral soil and open previously closed canopies. Understanding the environmental or fire characteristics that explain post-fire invasive plant abundance would aid managers in efficiently finding and quickly responding to fire-caused infestations. To that end, we used an information-theoretic model-selection approach to assess the relative importance of abiotic environmental characteristics (topoedaphic position, distance from roads), pre-and post-fire biotic environmental characteristics (forest structure, understory vegetation, fuel load), and prescribed fire severity (measured in four different ways) in explaining invasive plant cover in ponderosa pine forest in South Dakota’s Black Hills. Environmental characteristics (distance from roads and post-fire forest structure) alone provided the most explanation of variation (26%) in post-fire cover of Verbascum thapsus (common mullein), but a combination of surface fire severity and environmental characteristics (pre-fire forest structure and distance from roads) explained 36–39% of the variation in post-fire cover of Cirsium arvense (Canada thistle) and all invasives together. For four species and all invasives together, their pre-fire cover explained more variation (26–82%) in post-fire cover than environmental and fire characteristics did, suggesting one strategy for reducing post-fire invasive outbreaks may be to find and control invasives before the fire. Finding them may be difficult, however, since pre-fire environmental characteristics explained only 20% of variation in pre-fire total invasive cover, and less for individual species. Thus, moderating fire intensity or targeting areas

  10. Avian response to fire in pine–oak forests of Great Smoky Mountains National Park following decades of fire suppression

    USGS Publications Warehouse

    Rose, Eli T.; Simons, Theodore R.

    2016-01-01

    Fire suppression in southern Appalachian pine–oak forests during the past century dramatically altered the bird community. Fire return intervals decreased, resulting in local extirpation or population declines of many bird species adapted to post-fire plant communities. Within Great Smoky Mountains National Park, declines have been strongest for birds inhabiting xeric pine–oak forests that depend on frequent fire. The buildup of fuels after decades of fire suppression led to changes in the 1996 Great Smoky Mountains Fire Management Plan. Although fire return intervals remain well below historic levels, management changes have helped increase the amount of fire within the park over the past 20 years, providing an opportunity to study patterns of fire severity, time since burn, and bird occurrence. We combined avian point counts in burned and unburned areas with remote sensing indices of fire severity to infer temporal changes in bird occurrence for up to 28 years following fire. Using hierarchical linear models that account for the possibility of a species presence at a site when no individuals are detected, we developed occurrence models for 24 species: 13 occurred more frequently in burned areas, 2 occurred less frequently, and 9 showed no significant difference between burned and unburned areas. Within burned areas, the top models for each species included fire severity, time since burn, or both, suggesting that fire influenced patterns of species occurrence for all 24 species. Our findings suggest that no single fire management strategy will suit all species. To capture peak occupancy for the entire bird community within xeric pine–oak forests, at least 3 fire regimes may be necessary; one applying frequent low severity fire, another using infrequent low severity fire, and a third using infrequently applied high severity fire.

  11. Seven hundred years of human-driven and climate-influenced fire activity in a British Columbia coastal temperate rainforest

    PubMed Central

    Gavin, Daniel G.; Starzomski, Brian M.

    2016-01-01

    While wildland fire is globally most common at the savannah-grassland ecotone, there is little evidence of fire in coastal temperate rainforests. We reconstructed fire activity with a ca 700-year fire history derived from fire scars and stand establishment from 30 sites in a very wet (up to 4000 mm annual precipitation) temperate rainforest in coastal British Columbia, Canada. Drought and warmer temperatures in the year prior were positively associated with fire events though there was little coherence of climate indices on the years of fires. At the decadal scale, fires were more likely to occur after positive El Niño-Southern Oscillation and Pacific Decadal Oscillation phases and exhibited 30-year periods of synchrony with the negative phase of the Arctic Oscillation. Fire frequency was significantly inversely correlated with the distance from former Indigenous habitation sites and fires ceased following cultural disorganization caused by disease and other European impacts in the late nineteenth century. Indigenous people were likely to have been the primary ignition source in this and many coastal temperate rainforest settings. These data are directly relevant to contemporary forest management and discredit the myth of coastal temperate rainforests as pristine landscapes. PMID:27853581

  12. [Effects of fire recurrence on fire behaviour in cork oak woodlands (Quercus suber L.) and Mediterranean shrublands over the last fifty years].

    PubMed

    Schaffhauser, Alice; Pimont, François; Curt, Thomas; Cassagne, Nathalie; Dupuy, Jean-Luc; Tatoni, Thierry

    2015-12-01

    Past fire recurrence impacts the vegetation structure, and it is consequently hypothesized to alter its future fire behaviour. We examined the fire behaviour in shrubland-forest mosaics of southeastern France, which were organized along a range of fire frequency (0 to 3-4 fires along the past 50 years) and had different time intervals between fires. The mosaic was dominated by Quercus suber L. and Erica-Cistus shrubland communities. We described the vegetation structure through measurements of tree height, base of tree crown or shrub layer, mean diameter, cover, plant water content and bulk density. We used the physical model Firetec to simulate the fire behaviour. Fire intensity, fire spread, plant water content and biomass loss varied significantly according to fire recurrence and vegetation structure, mainly linked to the time since the last fire, then the number of fires. These results confirm that past fire recurrence affects future fire behaviour, with multi-layered vegetation (particularly high shrublands) producing more intense fires, contrary to submature Quercus woodlands that have not burnt since 1959 and that are unlikely to reburn. Further simulations, with more vegetation scenes according to shrub and canopy covers, will complete this study in order to discuss the fire propagation risk in heterogeneous vegetation, particularly in the Mediterranean area, with a view to a local management of these ecosystems. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  13. Rainfall and geomorphic aspects of post-fire soil erosion - Schultz Fire 2010

    Treesearch

    Ann Youberg; Karen A. Koestner; Daniel G. Neary; Peter E. Koestner

    2011-01-01

    The human-caused Schultz Fire near Flagstaff, Arizona burned 6,100 ha (15,075 acres) on the Coconino National Forest between June 20th and 30th, 2010. Ignited by an abandoned campfire, high winds drove the fire over approximately 60% of the total area burned during the first 12 hours (U.S. Forest Service, 2010). The majority of the area burned at moderate (27%) or high...

  14. Post-oil-spill fires at Ugbomro (Niger Delta): a new vista in soil-pollution studies.

    PubMed

    Osuji, Leo C; Ukale, Eseoghene E

    2005-10-01

    Reconnaissance of the post-oil-spill, fire-scourged site at Ugbomro, in the Niger Delta, was contingent upon the loud public outcry and galvanizing hue that ensued the widespread conflagration. Sampling was carried out by the grid technique, and fire-scourged soils and their unaffected controls were analyzed. Contrary to the 'celebrated' opinion of some that the fires improvised bush fallowing for cropping, the site had witnessed severe impoverishment as evidenced by the hitherto neglected insidious impact of such infernos on soil macronutrients. Alterations in physico-chemical properties (pH, conductivity, etc.) provided adequate bases for this conclusion, and offered broad explanations for the paucity of macronutrients in affected soils. For instance, a pH range of 3.1-3.8 hindered N2 fixation and other metabolic activities that enhance mineralization. Elaeis guineensis in a density of 3 stands/m2 at the control site was the only tree-form not charred beyond recognition.Against future fires, it is important to strengthen contingencies for more-expedient clean-up responses to oil spills to severe possibilities of in situ conflagrations. Nutrient supplementations, revegetation, and site surveillance should disengage the 'unsighted fingers' of sabotage. A careful husbandry of these measures might re-establish nutrient stability, and forestall future re-occurrence of such effacing incidents.

  15. Post-wildfire logging hinders regeneration and increases fire risk.

    PubMed

    Donato, D C; Fontaine, J B; Campbell, J L; Robinson, W D; Kauffman, J B; Law, B E

    2006-01-20

    We present data from a study of early conifer regeneration and fuel loads after the 2002 Biscuit Fire, Oregon, USA, with and without postfire logging. Natural conifer regeneration was abundant after the high-severity fire. Postfire logging reduced median regeneration density by 71%, significantly increased downed woody fuels, and thus increased short-term fire risk. Additional reduction of fuels is necessary for effective mitigation of fire risk. Postfire logging can be counterproductive to the goals of forest regeneration and fuel reduction.

  16. Contrasting long-term survival of two outplanted Mojave Desert perennials for post-fire revegetation

    USGS Publications Warehouse

    Scoles-Sciulla, Sara J.; Defalco, Lesley A.; Esque, Todd C.

    2015-01-01

    Post-fire recovery of arid shrublands is typically slow, and planting greenhouse-raised seedlings may be a means of jump-starting this process. Recovery can be further accelerated by understanding the factors controlling post-planting survival. In fall 2007 and 2009, we outplanted seedlings of two contrasting native evergreen shrubs—fast-growing Nevada jointfir and slow-growing blackbrush—across five burned sites in the Mojave Desert. To increase soil moisture and optimize seedling survival, we experimentally applied and evaluated soil amendments and supplemental watering. We also evaluated two herbicides that reduce competitive invasive annual grasses and two types of herbivore protection. Survival of jointfir outplanted in 2007 was 61% after 43 months, and site largely influenced survival, while herbicide containing imazapic applied more than one year after outplanting reduced survival. Reduced survival of jointfir outplanted in 2009 coincided with delayed seasonal precipitation that intensified foliar damage by small mammals. In contrast, blackbrush survival was 4% after 43 months, and was influenced by site, type of herbivore protection, and greenhouse during the 2007 outplanting, and soil amendment during 2009. Counter to expectations, we found that supplemental watering and soil amendments did not influence long-term survival of either blackbrush or jointfir. Shrub species with rapid growth rates and broad environmental tolerances, such as jointfir, make ideal candidates for outplanting, provided that seedlings are protected from herbivores. Re-introduction of species with slow growth rates and narrow environmental tolerances, such as blackbrush, requires careful consideration to optimize pre- and post-planting conditions.

  17. Fire weather in western Oregon and western Washington in 1952 compared with other years.

    Treesearch

    Owen P. Cramer

    1953-01-01

    How did the potential burning conditions of the 1952 fire season compare with those of previous years? The answer is important to those who protect forests from fire. Knowing the relative severity of the burning conditions will help them judge the effectiveness of their fire protection programs. This paper reports ratings of the weather factors most closely related to...

  18. Rice straw mulch for post-fire erosion control: assessing non-target effects on vegetation communities

    Treesearch

    Kristen L. Shive; Becky L. Estes; Angela M. White; Hugh D. Safford; Kevin L. O' Hara; Scott L. Stephens

    2017-01-01

    Straw mulch is commonly used for post-fire erosion control in severely burned areas but this practice can introduce non-native species, even when certified weed-free straw is used. Rice straw has recently been promoted as an alternative to wheat under the hypothesis that non-native species that are able to grow in a rice field are unlikely to establish in dry forested...

  19. Firefighter attitudes, norms, beliefs, barriers, and behaviors toward post-fire decontamination processes in an era of increased cancer risk.

    PubMed

    Harrison, Tyler R; Muhamad, Jessica Wendorf; Yang, Fan; Morgan, Susan E; Talavera, Ed; Caban-Martinez, Alberto; Kobetz, Erin

    2018-04-01

    Firefighters are exposed to carcinogens such as volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during fires and from their personal protective equipment (PPE). Recent research has shown that decontamination processes can reduce contamination on both gear and skin. While firefighter cultures that honor dirty gear are changing, little is known about current attitudes and behaviors toward decontamination in the fire service. Four hundred eighty-five firefighters from four departments completed surveys about their attitudes, beliefs, perceived norms, barriers, and behaviors toward post-fire decontamination processes. Overall, firefighters reported positive attitudes, beliefs, and perceived norms about decontamination, but showering after a fire was the only decontamination process that occurred regularly, with field decontamination, use of cleansing wipes, routine gear cleaning, and other behaviors all occurring less frequently. Firefighters reported time and concerns over wet gear as barriers to decontamination.

  20. Population and Individual Elephant Response to a Catastrophic Fire in Pilanesberg National Park

    PubMed Central

    Woolley, Leigh-Ann; Millspaugh, Joshua J.; Woods, Rami J.; Janse van Rensburg, Samantha; Mackey, Robin L.; Page, Bruce; Slotow, Rob

    2008-01-01

    In predator-free large herbivore populations, where density-dependent feedbacks occur at the limit where forage resources can no longer support the population, environmental catastrophes may play a significant role in population regulation. The potential role of fire as a stochastic mass-mortality event limiting these populations is poorly understood, so too the behavioural and physiological responses of the affected animals to this type of large disturbance event. During September 2005, a wildfire resulted in mortality of 29 (18% population mortality) and injury to 18, African elephants in Pilanesberg National Park, South Africa. We examined movement and herd association patterns of six GPS-collared breeding herds, and evaluated population physiological response through faecal glucocorticoid metabolite (stress) levels. We investigated population size, structure and projected growth rates using a simulation model. After an initial flight response post-fire, severely injured breeding herds reduced daily displacement with increased daily variability, reduced home range size, spent more time in non-tourist areas and associated less with other herds. Uninjured, or less severely injured, breeding herds also shifted into non-tourist areas post-fire, but in contrast, increased displacement rate (both mean and variability), did not adjust home range size and formed larger herds post-fire. Adult cow stress hormone levels increased significantly post-fire, whereas juvenile and adult bull stress levels did not change significantly. Most mortality occurred to the juvenile age class causing a change in post-fire population age structure. Projected population growth rate remained unchanged at 6.5% p.a., and at current fecundity levels, the population would reach its previous level three to four years post-fire. The natural mortality patterns seen in elephant populations during stochastic events, such as droughts, follows that of the classic mortality pattern seen in predator

  1. Life-history traits predict perennial species response to fire in a desert ecosystem

    PubMed Central

    Shryock, Daniel F; DeFalco, Lesley A; Esque, Todd C

    2014-01-01

    The Mojave Desert of North America has become fire-prone in recent decades due to invasive annual grasses that fuel wildfires following years of high rainfall. Perennial species are poorly adapted to fire in this system, and post-fire shifts in species composition have been substantial but variable across community types. To generalize across a range of conditions, we investigated whether simple life-history traits could predict how species responded to fire. Further, we classified species into plant functional types (PFTs) based on combinations of life-history traits and evaluated whether these groups exhibited a consistent fire-response. Six life-history traits varied significantly between burned and unburned areas in short (up to 4 years) or long-term (up to 52 years) post-fire datasets, including growth form, lifespan, seed size, seed dispersal, height, and leaf longevity. Forbs and grasses consistently increased in abundance after fire, while cacti were reduced and woody species exhibited a variable response. Woody species were classified into three PFTs based on combinations of life-history traits. Species in Group 1 increased in abundance after fire and were characterized by short lifespans, small, wind-dispersed seeds, low height, and deciduous leaves. Species in Group 2 were reduced by fire and distinguished from Group 1 by longer lifespans and evergreen leaves. Group 3 species, which also decreased after fire, were characterized by long lifespans, large non-wind dispersed seeds, and taller heights. Our results show that PFTs based on life-history traits can reliably predict the responses of most species to fire in the Mojave Desert. Dominant, long-lived species of this region possess a combination of traits limiting their ability to recover, presenting a clear example of how a novel disturbance regime may shift selective environmental pressures to favor alternative life-history strategies. PMID:25247062

  2. Life-history traits predict perennial species response to fire in a desert ecosystem

    USGS Publications Warehouse

    Shryock, Daniel F.; DeFalco, Lesley A.; Esque, Todd C.

    2014-01-01

    The Mojave Desert of North America has become fire-prone in recent decades due to invasive annual grasses that fuel wildfires following years of high rainfall. Perennial species are poorly adapted to fire in this system, and post-fire shifts in species composition have been substantial but variable across community types. To generalize across a range of conditions, we investigated whether simple life-history traits could predict how species responded to fire. Further, we classified species into plant functional types (PFTs) based on combinations of life-history traits and evaluated whether these groups exhibited a consistent fire-response. Six life-history traits varied significantly between burned and unburned areas in short (up to 4 years) or long-term (up to 52 years) post-fire datasets, including growth form, lifespan, seed size, seed dispersal, height, and leaf longevity. Forbs and grasses consistently increased in abundance after fire, while cacti were reduced and woody species exhibited a variable response. Woody species were classified into three PFTs based on combinations of life-history traits. Species in Group 1 increased in abundance after fire and were characterized by short lifespans, small, wind-dispersed seeds, low height, and deciduous leaves. Species in Group 2 were reduced by fire and distinguished from Group 1 by longer lifespans and evergreen leaves. Group 3 species, which also decreased after fire, were characterized by long lifespans, large non-wind dispersed seeds, and taller heights. Our results show that PFTs based on life-history traits can reliably predict the responses of most species to fire in the Mojave Desert. Dominant, long-lived species of this region possess a combination of traits limiting their ability to recover, presenting a clear example of how a novel disturbance regime may shift selective environmental pressures to favor alternative life-history strategies.

  3. Fire management strategies to maintain species population processes in a fragmented landscape of fire-interval extremes.

    PubMed

    Tulloch, Ayesha I T; Pichancourt, Jean-Baptiste; Gosper, Carl R; Sanders, Angela; Chadès, Iadine

    2016-10-01

    Changed fire regimes have led to declines of fire-regime-adapted species and loss of biodiversity globally. Fire affects population processes of growth, reproduction, and dispersal in different ways, but there is little guidance about the best fire regime(s) to maintain species population processes in fire-prone ecosystems. We use a process-based approach to determine the best range of fire intervals for keystone plant species in a highly modified Mediterranean ecosystem in southwestern Australia where current fire regimes vary. In highly fragmented areas, fires are few due to limited ignitions and active suppression of wildfire on private land, while in highly connected protected areas fires are frequent and extensive. Using matrix population models, we predict population growth of seven Banksia species under different environmental conditions and patch connectivity, and evaluate the sensitivity of species survival to different fire management strategies and burning intervals. We discover that contrasting, complementary patterns of species life-histories with time since fire result in no single best fire regime. All strategies result in the local patch extinction of at least one species. A small number of burning strategies secure complementary species sets depending on connectivity and post-fire growing conditions. A strategy of no fire always leads to fewer species persisting than prescribed fire or random wildfire, while too-frequent or too-rare burning regimes lead to the possible local extinction of all species. In low landscape connectivity, we find a smaller range of suitable fire intervals, and strategies of prescribed or random burning result in a lower number of species with positive growth rates after 100 years on average compared with burning high connectivity patches. Prescribed fire may reduce or increase extinction risk when applied in combination with wildfire depending on patch connectivity. Poor growing conditions result in a significantly

  4. Post-fire mulching for runoff and erosion mitigation; Part I: Effectiveness at reducing hillslope erosion rates

    Treesearch

    Peter R. Robichaud; Sarah A. Lewis; Joseph W. Wagenbrenner; Louise E. Ashmun; Robert E. Brown

    2013-01-01

    Mulch treatments often are used to mitigate post-fire increases in runoff and erosion rates but the comparative effectiveness of various mulches is not well established. The ability of mulch treatments to reduce sediment yields from natural rainfall and resulting overland flow was measured using hillslope plots on areas burned at high severity following four wildfires...

  5. Forest Fires Darken Snow for Years following Disturbance: Magnitude, Duration, and Composition of Light Absorbing Impurities in Seasonal Snow across a Chronosequence of Burned Forests in the Colorado River Headwaters

    NASA Astrophysics Data System (ADS)

    Gleason, K. E.; Arienzo, M. M.; Chellman, N.; McConnell, J.

    2017-12-01

    Charred forests shed black carbon and burned debris, which accumulates and concentrates on winter snowpack, reducing snow surface albedo, and subsequently increasing snowmelt rates, and advancing the date of snow disappearance. Forest fires have occurred across vast areas of the seasonal snow zone in recent decades, however we do not understand the long-term implications of burned forests in montane headwaters to snow hydrology and downstream water resources. Across a chronosequence of nine burned forests in the Colorado River Headwaters, we sampled snow throughout the complete snowpack profile to conserve the composition, properties, and vertical stratigraphy of impurities in the snowpack during maximum snow accumulation. Using state-of-the-art geochemical analyses, we determined the magnitude, composition, and particle size distribution of black carbon, dust, and other impurities in the snowpack relative to years-since fire. Forest fires continue to darken snow for many years following fire, however the magnitude, composition, and particle size distribution of impurities change through time, altering the post-fire radiative forcing on snow as a burned forest ages.

  6. Major atmospheric emissions from peat fires in Southeast Asia during non-drought years: evidence from the 2013 Sumatran fires

    NASA Astrophysics Data System (ADS)

    Gaveau, David L. A.; Salim, Mohammad A.; Hergoualc'h, Kristell; Locatelli, Bruno; Sloan, Sean; Wooster, Martin; Marlier, Miriam E.; Molidena, Elis; Yaen, Husna; Defries, Ruth; Verchot, Louis; Murdiyarso, Daniel; Nasi, Robert; Holmgren, Peter; Sheil, Douglas

    2014-08-01

    Trans-boundary haze events in Southeast Asia are associated with large forest and peatland fires in Indonesia. These episodes of extreme air pollution usually occur during drought years induced by climate anomalies from the Pacific (El Niño Southern Oscillation) and Indian Oceans (Indian Ocean Dipole). However, in June 2013 - a non-drought year - Singapore's 24-hr Pollutants Standards Index reached an all-time record 246 (rated ``very unhealthy''). Here, we show using remote sensing, rainfall records and other data, that the Indonesian fires behind the 2013 haze followed a two-month dry spell in a wetter-than-average year. These fires were short-lived (one week) and limited to a localized area in Central Sumatra (1.6% of Indonesia): burning an estimated 163,336 ha, including 137,044 ha (84%) on peat. Most burning was confined to deforested lands (82%; 133,216 ha). The greenhouse gas (GHG) emissions during this brief, localized event were considerable: 172 +/- 59 Tg CO2-eq (or 31 +/- 12 Tg C), representing 5-10% of Indonesia's mean annual GHG emissions for 2000-2005. Our observations show that extreme air pollution episodes in Southeast Asia are no longer restricted to drought years. We expect major haze events to be increasingly frequent because of ongoing deforestation of Indonesian peatlands.

  7. The role of fire severity, distance from fire perimeter and vegetation on post-fire recovery of small-mammal communities in chaparal

    Treesearch

    Jay Diffendorfer; Genie M. Fleming; Scott Tremor; Wayne Spencer; Jan L. Beyers

    2012-01-01

    Chaparral shrublands in southern California, US, exhibit significant biodiversity but are prone to large, intense wildfires. Debate exists regarding fuel reduction to prevent such fires in wildland areas, but the effects of these fires on fauna are not well understood. We studied whether fire severity and distance from unburned fire perimeter influenced recovery of the...

  8. Wildfires and post-fire erosion risk in a coastal area under severe anthropic pressure associated with the touristic fluxes

    NASA Astrophysics Data System (ADS)

    Canu, Annalisa; Arca, Bachisio; Pellizzaro, Grazia; Valeriano Pintus, Gian; Ferrara, Roberto; Duce, Pierpaolo

    2017-04-01

    In the last decades a rapid and intense development of the tourism industry led to an increasing of anthropic pressure on several coastal areas of Sardinia. This fact not only modified the coastal aesthetics, but has also generated an increase of risk for the environment. This phenomenon affected also the ancient structure of the landscape with a negative impact mainly caused by the following factors: land abandonment, wildfire occurrence, post-fire erosion, urbanization. These regional changes can be analyzed in detail by considering the geo-diachronic dynamics. The main objectives of this work were i) to perform a diachronic analysis of land use and land cover dynamics, ii) to analyse the recent dynamics of wildfires, and iii) to predict the soil erosion risk in relation to land use change occurred between the 1950s and the 2000s. The study was realized in a coastal area located in North-East Sardinia where the geo-historical processes were summarized and organized in a geographic information system that has been employed to examine the landscape variations at three different time steps: 1954, 1977 and 2000. In addition, different scenarios of wildfire propagation were simulated by FlamMap in order to estimate the spatial pattern of fire danger factors in the study area. Afterwards, maps of post-fire soil erosion were produced to identify the temporal and spatial variations of the erosion risk. The results show how the changes in land use and the significant and rapid increase of the residential areas affect the risk of both wildfires and post-fire soil erosion. The study reveals the capabilities of this type of approach and can be used by management agencies and policy makers e in sustainable landscape management planning. This approach can be extended to other regions of the Mediterranean basin characterized by complex interactions among landscape and anthropic factors affecting the environmental risk.

  9. Post-fire fluxes and sources of carbon in previously burnt tropical swamp peatlands, Brunei

    NASA Astrophysics Data System (ADS)

    Lupascu, M.; Akhtar, H.; Smith, T. E. L.; Sukmaria binti Hj Sukri, R.

    2017-12-01

    Tropical peatlands hold about 15-19% of the global organic carbon (C) pool of which 77% in Southeast Asia. Nonetheless Southeast Asian peatlands have been exploited for timber and land for agriculture leading to rapid deforestation, extensive drainage and frequent fires. Direct C-emissions through peat combustion must be quantified to examine the impact of peat fires on global and regional C-budgets, however it is also essential to evaluate oxidative decomposition of peat after fires for a complete understanding of ecosystem-scale fire impact. This kind of investigation is necessary also to understand the effect of peat burning on peat decomposition, because burning effects on the belowground environment are variable, depending on burnt frequency and fire severity. After a fire, ecosystems act as a C-source for months-to-years as ecosystem-respiration (Reco) exceeds photosynthesis. Furthermore during fires, the surface peat with a higher proportion of the more modern rapidly-cycled C burns preferentially. The loss of the surface peat possibly can reduce oxidative soil CO2 emissions, as the deeper, older peat, has more recalcitrant compounds. However, CO2emissions from this old C pool are a net flux to the atmosphere compared to the modern C. Within this context, we are quantifying the magnitudes and patterns of ecosystem-atmosphere fluxes of carbon dioxide (CO2) and methane (CH4) through cavity-ring spectroscopy in different transects of an intact tropical peat swamp forest and in two degraded forest areas affected by two and six fires over the last 40 years in Brunei, on the island of Borneo. We are using natural tracers such as δ13C and 14C to investigate the age and sources (auto- and heterotrophic) of C contributing to Reco and we are continuously monitoring soil temperature and water table level. Preliminary data show a similar magnitude of CO2 efflux between the intact (5.3 µmol CO2 m-2 s-1) and burnt areas (6.4 µmol CO2 m-2 s-1), with higher soil

  10. Fire scars and tree vigor following prescribed fires in Missouri Ozark upland forests

    Treesearch

    Aaron P. Stevenson; Rose-Marie Muzika; Richard P. Guyette

    2008-01-01

    The goal of our project was to examine basal fire scars caused by prescribed fires and tree vigor in upland forests of the Missouri Ozarks. Fire scar data were collected in 100 plots from black oak (Quercus velutina Lam.), scarlet oak (Q. coccinea Muench.), Shumard oak (Q. shumardii Buckl.), post oak (Q...

  11. Watershed response and recovery from the Will Fire: ten years of observations

    Treesearch

    Kenneth B. Roby

    1989-01-01

    Watershed response and recovery from a wildfire which burned 95 percent of the Williams Creek watershed in 1979 were monitored. Ground cover reduced to 11 percent by the fire increased to 80 percent by 1983. Grasses seeded for erosion control provided less than 10 percent cover until 3 years following the fire, and no significant difference in ground cover was found...

  12. Decreases in Soil Moisture and Organic Matter Quality Suppress Microbial Decomposition Following a Boreal Forest Fire

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Holden, Sandra R.; Berhe, Asmeret A.; Treseder, Kathleen K.

    Climate warming is projected to increase the frequency and severity of wildfires in boreal forests, and increased wildfire activity may alter the large soil carbon (C) stocks in boreal forests. Changes in boreal soil C stocks that result from increased wildfire activity will be regulated in part by the response of microbial decomposition to fire, but post-fire changes in microbial decomposition are poorly understood. Here, we investigate the response of microbial decomposition to a boreal forest fire in interior Alaska and test the mechanisms that control post-fire changes in microbial decomposition. We used a reciprocal transplant between a recently burnedmore » boreal forest stand and a late successional boreal forest stand to test how post-fire changes in abiotic conditions, soil organic matter (SOM) composition, and soil microbial communities influence microbial decomposition. We found that SOM decomposing at the burned site lost 30.9% less mass over two years than SOM decomposing at the unburned site, indicating that post-fire changes in abiotic conditions suppress microbial decomposition. Our results suggest that moisture availability is one abiotic factor that constrains microbial decomposition in recently burned forests. In addition, we observed that burned SOM decomposed more slowly than unburned SOM, but the exact nature of SOM changes in the recently burned stand are unclear. Finally, we found no evidence that post-fire changes in soil microbial community composition significantly affect decomposition. Taken together, our study has demonstrated that boreal forest fires can suppress microbial decomposition due to post-fire changes in abiotic factors and the composition of SOM. Models that predict the consequences of increased wildfires for C storage in boreal forests may increase their predictive power by incorporating the observed negative response of microbial decomposition to boreal wildfires.« less

  13. Understory response to varying fire frequencies after 20 years of prescribed burning in an upland oak forest

    USGS Publications Warehouse

    Burton, J.A.; Hallgren, S.W.; Fuhlendorf, S.D.; Leslie, David M.

    2011-01-01

    Ecosystems in the eastern United States that were shaped by fire over thousands of years of anthropogenic burning recently have been subjected to fire suppression resulting in significant changes in vegetation composition and structure and encroachment by invasive species. Renewed interest in use of fire to manage such ecosystems will require knowledge of effects of fire regime on vegetation. We studied the effects of one aspect of the fire regime, fire frequency, on biomass, cover and diversity of understory vegetation in upland oak forests prescribe-burned for 20 years at different frequencies ranging from zero to five fires per decade. Overstory canopy closure ranged from 88 to 96% and was not affected by fire frequency indicating high tolerance of large trees for even the most frequent burning. Understory species richness and cover was dominated by woody reproduction followed in descending order by forbs, C3 graminoids, C4 grasses, and legumes. Woody plant understory cover did not change with fire frequency and increased 30% from one to three years after a burn. Both forbs and C3 graminoids showed a linear increase in species richness and cover as fire frequency increased. In contrast, C4 grasses and legumes did not show a response to fire frequency. The reduction of litter by fire may have encouraged regeneration of herbaceous plants and helped explain the positive response of forbs and C3 graminoids to increasing fire frequency. Our results showed that herbaceous biomass, cover, and diversity can be managed with long-term prescribed fire under the closed canopy of upland oak forests. ?? 2011 Springer Science+Business Media B.V.

  14. Temporal characterisation of soil-plant natural recovery related to fire severity in burned Pinus halepensis Mill. forests.

    PubMed

    Moya, D; González-De Vega, S; García-Orenes, F; Morugán-Coronado, A; Arcenegui, V; Mataix-Solera, J; Lucas-Borja, M E; De Las Heras, J

    2018-05-28

    Despite Mediterranean ecosystems' high resilience to fire, both climate and land use change, and alterations in fire regimes increase their vulnerability to fire by affecting the long-term natural recovery of ecosystem services. The objective of this work is to study the effects of fire severity on biochemical soil indicators, such as chemical composition or enzymatic activity, related to time after fire and natural vegetation recovery (soil-plant interphase). Soil samples from three wildfires occurring 3, 15 and 21 years ago were taken in the south-eastern Iberian Peninsula (semiarid climate). Sampling included three fire severity levels in naturally regenerated (and changing to shrublands) Pinus halepensis Mill. forests. In the short-term post-fire period, phosphorus concentration, electrical conductivity and urease activity were positively linked to fire severity, and also influenced β-glucosidade activity in a negative relationship. During the 15-21-year post-fire period, the effects related to medium-high fire severity were negligible and soil quality indicators were linked to natural regeneration success. The results showed that most soil properties recovered in the long term after fire (21 years). These outcomes will help managers and stakeholders to implement management tools to stabilise soils and to restore burned ecosystems affected by medium-high fire severity. Such knowledge can be considered in adaptive forest management to reduce the negative effects of wildfires and desertification, and to improve the resilience of vulnerable ecosystems in a global change scenario. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. First post-fire flush in a Mediterranean temporary stream: source ascription in bed sediments

    NASA Astrophysics Data System (ADS)

    Estrany Bertos, Joan; García-Comendador, Julián; Fortesa, Josep; Calsamiglia, Aleix; Garcias, Francesca

    2017-04-01

    First flushes can be of great importance for suspended-sediment transport in fluvial systems of drylands, being temporary streams a characteristic feature of Mediterranean basins. After a wildfire, storm flows may enhance runoff delivery to channels and then increasing the first-flush effect. 137Cs and 210Pbex were used as tracers for recognizing the first post-fire flush effect in the source ascription of bed sediments temporarily stored in a Mediterranean temporary stream severely affected by a wildfire. Thirty potential sediment source samples were collected along the main stem of a catchment located in Mallorca (Spain) during a field campaign developed some weeks after the wildfire. The sample collection was designed considering the wildfire affection, and also distinguishing between soil surface and channel bank. To quantify the relative source contribution to the bed sediment temporarily stored, five sediment samples -deposited during the first storm occurred three months after the wildfire- were collected into the bed stream of the main channel. The 137Cs and 210Pbex concentrations were measured by gamma spectrometry. Then, a linear mixing model was used to establish the relative contribution of each source type to the bed sediments discerning between the most upstream and the downstream parts of the catchment. Post-fire first-flush effect was generated by a torrential event with a suspended-sediment concentration peak ca. 33,618 mg L-1, although transmission losses under a very low runoff coefficient (1%) promoted sediment deposition. Significant differences were observed in fallout radionuclide concentrations between burned surface soil and channel bank samples (p < 0.05), as well as between burned and unburned sources at the downstream part of the catchment (p < 0.01). The radioactivity concentrations in bed sediments samples were statistically similar (p > 0.05). Source ascription in bed sediments in the middle stream shows that 67% was generated in

  16. Effects of high fire frequency in creosote bush scrub vegetation of the Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.

    2012-01-01

    Plant invasions can increase fire frequency in desert ecosystems where fires were historically infrequent. Although there are many resource management concerns associated with high frequency fire in deserts, fundamental effects on plant community characteristics remain largely unstudied. Here I describe the effects of fire frequency on creosote bush scrub vegetation in the Mojave Desert, USA. Biomass of the invasive annual grass Bromus rubens L. increased following fire, but did not increase further with additional fires. In contrast, density, cover and species richness of native perennial plants each decreased following fire and continued to decrease with subsequent fires, although not as dramatically as after the initial fire. Responses were similar 5 and 14 years post-fire, except that cover of Hymenoclea salsola Torr. & A. Gray and Achnatherum speciosa Trin. & Rupr. both increased in areas burnt once. These results suggest that control of B. rubens may be equally warranted after one, two or three fires, but revegetation of native perennial plants is most warranted following multiple fires. These results are valid within the scope of this study, which is defined as relatively short term vegetation responses (???14 years) to short fire return intervals (6.3 and 7.3 years for the two and three fire frequency levels) within creosote bush scrub of the Mojave Desert. ?? 2012 IAWF.

  17. Assessment of fire-damaged mesquite trees 8 years following an illegal burn

    Treesearch

    Gerald J. Gottfried; Peter F. Ffolliott; Pablo Garcia; Diego Valdez-Zamudio; Akram Al-Khouri

    2003-01-01

    Effects of an illegal burn on the Santa Rita Experimental Range on mesquite (Prosopis velutina) survival in the semidesert grass-shrub ecosystem was initially assessed in terms of firedamage classes 18 months after the fire and again 8 years after the burn. While many of the mesquite trees on the burned site were damaged by the fire, some of the trees appear to have...

  18. Effectiveness of post-fire seeding at the Fitzner-Eberhardt Arid Land Ecology Reserve, Washington

    USGS Publications Warehouse

    Wirth, Troy A.; Pyke, David A.

    2011-01-01

    survival rates that warrant further testing; however, transplants located closer to washes tended to have the highest survival rates. Overall, the low-elevation aerial and drill seedings, and the high-elevation drill seedings resulted in significant numbers of seedlings. Further research is needed on methods that provide land managers with critical information about whether or not to seed post-fire areas including status of pre-fire vegetation and estimates of plant mortality due to fire.

  19. 12,000-Years of fire regime drivers in the lowlands of Transylvania (Central-Eastern Europe): a data-model approach

    NASA Astrophysics Data System (ADS)

    Feurdean, A.; Liakka, J.; Vannière, B.; Marinova, E.; Hutchinson, S. M.; Mosburgger, V.; Hickler, T.

    2013-12-01

    The usefulness of sedimentary charcoal records to document centennial to millennial scale trends in aspects of fire regimes (frequency, severity) is widely acknowledged, yet the long-term variability in these regimes is poorly understood. Here, we use a high-resolution, multi-proxy analysis of a lacustrine sequence located in the lowlands of Transylvania (NW Romania), alongside global climate simulations in order to disentangle the drivers of fire regimes in this dry climatic region of Central-Eastern Europe. Periods of greater fire activity and frequency occurred between 10,700 and 7100 cal yr BP (mean Fire Interval = mFI 112 yr), and between 3300 and 700 cal yr BP (mFI 150 yr), whereas intervals of lower fire activity were recorded between 12,000 and 10,700 cal yr BP (mFI 217 yr), 7100 and 3300 cal yr BP (mFI 317 yr), and over last 700 years (no fire events detected). We found good correlations between simulated early summer (June, July) soil moisture content and near-surface air temperature with fire activity, particularly for the early to mid Holocene. A climate-fire relationship is further supported by local hydrological changes, i.e., lake level and runoff fluctuations. Fuel limitation, as a result of arid and strongly seasonal climatic conditions, led to low fire activity before 10,700 cal yr BP. However, fires were most frequent during climatically drier phases for the remaining, fuel-sufficient, part of the Holocene. Our results also suggest that the occurrence of more frequent fires in the early Holocene has kept woodlands open, promoted grassland abundance and sustained a more flammable ecosystem (mFI < 150 years) whereas the decline in fire risk under cooler and wetter climate conditions (mFI = 317 years) favoured woodland development. From 3300 cal yr BP, human impacts clearly were partly responsible for changes in fire activity, first increasing fire frequency and severity in periods with fire-favourable climatic conditions (halving the mFI from 300

  20. Management impacts on fire occurrence: A comparison of fire regimes of African and South American tropical savannas in different protected areas.

    PubMed

    Alvarado, Swanni T; Silva, Thiago Sanna Freire; Archibald, Sally

    2018-07-15

    Humans can alter fire dynamics in grassland systems by changing fire frequency, fire seasonality and fuel conditions. These changes have effects on vegetation structure and recovery, species composition, and ecosystem function. Understanding how human management can affect fire regimes is vital to detect potential changes in the resilience of plant communities, and to predict vegetation responses to human interventions. We evaluated the fire regimes of two recently protected areas in Madagascar (Ibity and Itremo NPA) and one in Brazil (Serra do Cipó NP) before and after livestock exclusion and fire suppression policies. We compare the pre- and post-management fire history in these areas and analyze differences in terms of total annual burned area, density of ignitions, burn scar size distribution, fire return period and seasonal fire distribution. More than 90% of total park areas were burned at least once during the studied period, for all parks. We observed a significant reduction in the number of ignitions for Ibity NPA and Serra do Cipó NP after livestock exclusion and active fire suppression, but no significant change in total burned area for each protected area. We also observed a seasonal shift in burning, with fires happening later in the fire season (October-November) after management intervention. However, the protected areas in Madagascar had shorter fire return intervals (3.23 and 1.82 years) than those in Brazil (7.91 years). Our results demonstrate that fire exclusion is unattainable, and probably unwarranted in tropical grassland conservation areas, but show how human intervention in fire and vegetation patterns can alter various aspects of the fire regimes. This information can help with formulating realistic and effective fire management policies in these valuable conservation areas. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Major atmospheric emissions from peat fires in Southeast Asia during non-drought years: evidence from the 2013 Sumatran fires

    PubMed Central

    Gaveau, David L. A.; Salim, Mohammad A.; Hergoualc'h, Kristell; Locatelli, Bruno; Sloan, Sean; Wooster, Martin; Marlier, Miriam E.; Molidena, Elis; Yaen, Husna; DeFries, Ruth; Verchot, Louis; Murdiyarso, Daniel; Nasi, Robert; Holmgren, Peter; Sheil, Douglas

    2014-01-01

    Trans-boundary haze events in Southeast Asia are associated with large forest and peatland fires in Indonesia. These episodes of extreme air pollution usually occur during drought years induced by climate anomalies from the Pacific (El Niño Southern Oscillation) and Indian Oceans (Indian Ocean Dipole). However, in June 2013 – a non-drought year – Singapore's 24-hr Pollutants Standards Index reached an all-time record 246 (rated “very unhealthy”). Here, we show using remote sensing, rainfall records and other data, that the Indonesian fires behind the 2013 haze followed a two-month dry spell in a wetter-than-average year. These fires were short-lived (one week) and limited to a localized area in Central Sumatra (1.6% of Indonesia): burning an estimated 163,336 ha, including 137,044 ha (84%) on peat. Most burning was confined to deforested lands (82%; 133,216 ha). The greenhouse gas (GHG) emissions during this brief, localized event were considerable: 172 ± 59 Tg CO2-eq (or 31 ± 12 Tg C), representing 5–10% of Indonesia's mean annual GHG emissions for 2000–2005. Our observations show that extreme air pollution episodes in Southeast Asia are no longer restricted to drought years. We expect major haze events to be increasingly frequent because of ongoing deforestation of Indonesian peatlands. PMID:25135165

  2. Major atmospheric emissions from peat fires in Southeast Asia during non-drought years: evidence from the 2013 Sumatran fires.

    PubMed

    Gaveau, David L A; Salim, Mohammad A; Hergoualc'h, Kristell; Locatelli, Bruno; Sloan, Sean; Wooster, Martin; Marlier, Miriam E; Molidena, Elis; Yaen, Husna; DeFries, Ruth; Verchot, Louis; Murdiyarso, Daniel; Nasi, Robert; Holmgren, Peter; Sheil, Douglas

    2014-08-19

    Trans-boundary haze events in Southeast Asia are associated with large forest and peatland fires in Indonesia. These episodes of extreme air pollution usually occur during drought years induced by climate anomalies from the Pacific (El Niño Southern Oscillation) and Indian Oceans (Indian Ocean Dipole). However, in June 2013--a non-drought year--Singapore's 24-hr Pollutants Standards Index reached an all-time record 246 (rated "very unhealthy"). Here, we show using remote sensing, rainfall records and other data, that the Indonesian fires behind the 2013 haze followed a two-month dry spell in a wetter-than-average year. These fires were short-lived (one week) and limited to a localized area in Central Sumatra (1.6% of Indonesia): burning an estimated 163,336 ha, including 137,044 ha (84%) on peat. Most burning was confined to deforested lands (82%; 133,216 ha). The greenhouse gas (GHG) emissions during this brief, localized event were considerable: 172 ± 59 Tg CO2-eq (or 31 ± 12 Tg C), representing 5-10% of Indonesia's mean annual GHG emissions for 2000-2005. Our observations show that extreme air pollution episodes in Southeast Asia are no longer restricted to drought years. We expect major haze events to be increasingly frequent because of ongoing deforestation of Indonesian peatlands.

  3. Dietary response of sympatric deer to fire using stable isotope analysis of liver tissue

    USGS Publications Warehouse

    Walter, W. David; Zimmerman, T.J.; Leslie, David M.; Jenks, J.A.

    2009-01-01

    Carbon (??13C) and nitrogen (??15N) isotopes in biological samples from large herbivores identify photosynthetic pathways (C3 vs. C4) of plants they consumed and can elucidate potential nutritional characteristics of dietary selection. Because large herbivores consume a diversity of forage types, ??13C and ??15N in their tissue can index ingested and assimilated diets through time. We assessed ??13C and ??15N in metabolically active liver tissue of sympatric mule deer (Odocoileus hemionus) and white-tailed deer (O. virginianus) to identify dietary disparity resulting from use of burned and unburned areas in a largely forested landscape. Interspecific variation in dietary disparity of deer was documented 2-3 years post-fire in response to lag-time effects of vegetative response to burning and seasonal (i.e., summer, winter) differences in forage type. Liver ??13C for mule deer were lower during winter and higher during summer 2 years post-fire on burned habitat compared to unburned habitat suggesting different forages were consumed by mule deer in response to fire. Liver ??15N for both species were higher on burned than unburned habitat during winter and summer suggesting deer consumed more nutritious forage on burned habitat during both seasons 2 and 3 years post-fire. Unlike traditional methods of dietary assessment that do not measure uptake of carbon and nitrogen from dietary components, analyses of stable isotopes in liver or similar tissue elucidated ??13C and ??15N assimilation from seasonal dietary components and resulting differences in the foraging ecology of sympatric species in response to fire.

  4. 29 CFR 1926.151 - Fire prevention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Fire prevention. 1926.151 Section 1926.151 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Fire Protection and Prevention § 1926.151 Fire... at or in the vicinity of operations which constitute a fire hazard, and shall be conspicuously posted...

  5. 29 CFR 1926.151 - Fire prevention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Fire prevention. 1926.151 Section 1926.151 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Fire Protection and Prevention § 1926.151 Fire... at or in the vicinity of operations which constitute a fire hazard, and shall be conspicuously posted...

  6. 29 CFR 1926.151 - Fire prevention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Fire prevention. 1926.151 Section 1926.151 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Fire Protection and Prevention § 1926.151 Fire... at or in the vicinity of operations which constitute a fire hazard, and shall be conspicuously posted...

  7. Assessing impacts of fire and post-fire mitigation on runoff and erosion from rangelands

    USDA-ARS?s Scientific Manuscript database

    Wildfires are a natural component of rangeland ecosystems, but fires can pose hydrologic hazards for ecological resources, infrastructure, property, and human life. There has been considerable research conducted on the effects of fire on hydrologic processes and erosion on shrublands and woodlands....

  8. Polycyclic aromatic hydrocarbons in post-fire soils of drained peatlands in western Meshchera (Moscow region, Russia)

    NASA Astrophysics Data System (ADS)

    Tsibart, A.; Gennadiev, A.; Koshovskii, T.; Watts, A.

    2014-12-01

    Polycyclic aromatic hydrocarbons (PAHs) are priority pollutants that arrive in the environment from numerous anthropogenic and natural sources, but the data on their natural sources including wildfires remain insufficient. The level of contamination and the composition of PAHs in soils of the areas affected by wildfires were studied in this work. The study was conducted in the Moscow region (Russia) in areas occupied by drained peatland and strongly damaged by fires in 2002, 2010 and 2012. The features of PAH accumulation and the profile distributions in histosols and histic podzols after the fires of different times were analyzed. It was shown that new soil horizons formed after the fires - Cpir, Hpir and incipient O horizons - and that these horizons differ in PAH accumulation rate. Maximal total concentrations of 14 PAHs were detected in charred peat horizons Hpir (up to 330 ng g-1) and in post-fire incipient O horizons (up to 180 ng g-1), but the high-molecular-weight PAHs (benz(ghi)perylene, benz(a)pyrene, benz(k)fluoranthene) were revealed only in charry peat horizons. The trends of higher PAH concentrations were found in cases when smoldering combustion resulted in rather thick residual peat horizons. In cases of almost complete pyrogenic destruction of He horizons, total PAH concentrations were no more than 50 ng g-1. Also, PAH accumulation in upper horizons of soils near the sites of the latest fires was observed.

  9. Comparison of the characteristics of fire and non-fire households in the 2004-2005 survey of fire department-attended and unattended fires.

    PubMed

    Greene, Michael A

    2012-06-01

    Comparison of characteristics of fire with non-fire households to determine factors differentially associated with fire households (fire risk factors). National household telephone survey in 2004-2005 by the US Consumer Product Safety Commission with 916 fire households and a comparison sample of 2161 non-fire households. There were an estimated 7.4 million fires (96.6% not reported to fire departments) with 130,000 injuries. Bivariate analysis and multivariate logistic regression analyses to assess differences in household characteristics. Significant factors associated with fire households were renting vs. owning (OR 1.988 p<0.0001); household members under 18 year of age (OR 1.277 p<0.0001); lack of residents over 64 years old (OR 0.552 p=0.0007); and college or higher education (some college OR 1.444 p=0.0360, college graduate OR 1.873, p<0.0001, postgraduate OR 2.156 p<0.0001). Not significant were age of house; race; ethnicity; and income. Number of smokers was borderline significant (OR 1.132 p=0.1019) but was significant in the subset of fire households with non-cooking fires (OR 1.383 p=0.0011). Single family houses were associated with non-fire households in the bivariate analysis but not in the multivariate analyses. Renting, household members under 18 years old and smokers are risk factors for unattended fires, similar to the literature for fatal and injury fires. Differences included household members over 65 years old (associated with non-fire households), college/postgraduate education (associated with fire households) and lack of significance of income. Preventing cooking fires (64% of survey incidents), smoking prevention efforts and fire prevention education for families with young children have the potential for reducing unattended fires and injuries.

  10. School Fires. Topical Fire Research Series. Volume 8, Issue 1

    ERIC Educational Resources Information Center

    US Department of Homeland Security, 2007

    2007-01-01

    Using the past 3 years of data, for 2003 to 2005, from the National Fire Incident Reporting System (NFIRS) database, the yearly national fire loss for fires on nonadult school properties is estimated at $85 million. Such losses are the result of an estimated annual average of 14,700 fires that required a fire department response. Fires on school…

  11. Development of life prediction capabilities for liquid propellant rocket engines. Post-fire diagnostic system for the SSME system architecture study

    NASA Technical Reports Server (NTRS)

    Gage, Mark; Dehoff, Ronald

    1991-01-01

    This system architecture task (1) analyzed the current process used to make an assessment of engine and component health after each test or flight firing of an SSME, (2) developed an approach and a specific set of objectives and requirements for automated diagnostics during post fire health assessment, and (3) listed and described the software applications required to implement this system. The diagnostic system described is a distributed system with a database management system to store diagnostic information and test data, a CAE package for visual data analysis and preparation of plots of hot-fire data, a set of procedural applications for routine anomaly detection, and an expert system for the advanced anomaly detection and evaluation.

  12. Post-fire suspended sediment dynamics in a Mediterranean terraced catchment using a nested approach

    NASA Astrophysics Data System (ADS)

    Garcia-Comendador, Julián; Fortesa, Josep; Calsamiglia, Aleix; Calvo-Cases, Adolfo; Estrany, Joan

    2017-04-01

    Wildfires promote serious disturbances in the hydrological and sediment dynamics at catchment scale modifying the runoff generation response and the sediment delivery. The hysteretic loops analyses can help to clarify some landscape changes induced by fire. Accordingly, these spatio-temporal relationships between discharge and sediment transport at event scale enable the location of sediment sources, the availability or depletion of sediment and the precipitation threshold necessary to generate functional hillslope-channel connectivity. In addition, a nested catchment approach allows the characterization of the hydro-sedimentological dynamics in different landscape compartments, observing the incidence of the changes generated in the landscape and its evolution to control soil erosion and to implement useful mitigation practices after fire. In July 2013 a large wildfire (2,450 ha) severely affected the western part of Mallorca (Balearic Islands, Spain). The hydrological and sediment delivery processes were assessed in the first three post-fire hydrological years in a representative catchment when the window of disturbance is typically more open. A nested approach was applied in which two gauging stations (i.e., US 1.2 km2 and DS 4.8 km2) were established in September 2013 with continuous measurement of rainfall, water and sediment yield. At DS, a minimal runoff (i.e., 11 mm with 2% of coefficient) and low sediment yield (i.e., 6.3 t km2 yr-1) were generated on average in the study period in which rainfall averaged amount (i.e., 468 mm ± 141) and intensities were representative of long-term records. The hysteretic analysis allowed a better understanding of the effects of wildfires and terraces in sediment yields. For the whole study period, the percentage distribution was 43% (US; two monitored years) and 40% (DS; three monitored years) for clockwise loops in front of 57% (US) and 60% (DS) for counter clockwise loops. This percentage of counter clockwise loops was

  13. Fire Suppression and Response

    NASA Technical Reports Server (NTRS)

    Ruff, Gary A.

    2004-01-01

    This report is concerned with the following topics regarding fire suppression:What is the relative effectiveness of candidate suppressants to extinguish a representative fire in reduced gravity, including high-O2 mole fraction, low -pressure environments? What are the relative advantages and disadvantages of physically acting and chemically-acting agents in spacecraft fire suppression? What are the O2 mole fraction and absolute pressure below which a fire cannot exist? What effect does gas-phase radiation play in the overall fire and post-fire environments? Are the candidate suppressants effective to extinguish fires on practical solid fuels? What is required to suppress non-flaming fires (smoldering and deep seated fires) in reduced gravity? How can idealized space experiment results be applied to a practical fire scenario? What is the optimal agent deployment strategy for space fire suppression?

  14. Phenology-based, remote sensing of post-burn disturbance windows in rangelands

    USGS Publications Warehouse

    Sankeya, Joel B.; Wallace, Cynthia S.A.; Ravi, Sujith

    2013-01-01

    Wildland fire activity has increased in many parts of the world in recent decades. Ecological disturbance by fire can accelerate ecosystem degradation processes such as erosion due to combustion of vegetation that otherwise provides protective cover to the soil surface. This study employed a novel ecological indicator based on remote sensing of vegetation greenness dynamics (phenology) to estimate variability in the window of time between fire and the reemergence of green vegetation. The indicator was applied as a proxy for short-term, post-fire disturbance windows in rangelands; where a disturbance window is defined as the time required for an ecological or geomorphic process that is altered to return to pre-disturbance levels. We examined variability in the indicator determined for time series of MODIS and AVHRR NDVI remote sensing data for a database of ∼100 historical wildland fires, with associated post-fire reseeding treatments, that burned 1990–2003 in cold desert shrub steppe of the Great Basin and Columbia Plateau of the western USA. The indicator-based estimates of disturbance window length were examined relative to the day of the year that fires burned and seeding treatments to consider effects of contemporary variability in fire regime and management activities in this environment. A key finding was that contemporary changes of increased length of the annual fire season could have indirect effects on ecosystem degradation, as early season fires appeared to result in longer time that soils remained relatively bare of the protective cover of vegetation after fires. Also important was that reemergence of vegetation did not occur more quickly after fire in sites treated with post-fire seeding, which is a strategy commonly employed to accelerate post-fire vegetation recovery and stabilize soil. Future work with the indicator could examine other ecological factors that are dynamic in space and time following disturbance – such as nutrient cycling

  15. Short- term effects of post-fire logging on runoff and soil erosion at two spatial scales

    NASA Astrophysics Data System (ADS)

    Malvar, Maruxa; Silva, Flavio; Prats, Sergio; Vieira, Diana; Keizer, Jacob

    2017-04-01

    Logging is the most common management practice after wildfires in forested areas in Portugal. Clearcutting is undertaken to recover burnt timber resources, to control resprouting, notably in the case of eucalypt plantations, and to reduce the risks of possible insect plagues, notably in the case of maritime pine because of the nematode plague. Still, relatively little is known about the combined effect of wildfire and post-fire logging on erosion processes. In the framework of the EU-FP7 project RECARE (www.recare-project.eu), the ESP team of the University of Aveiro set up an experiment to quantify the hydrological and erosion impacts of post-fire logging, at the scale of both 0.25 m2 micro-plots and 16 m2 plots. A eucalypt slope burnt in August 2015 by a moderate intensity fire and logged in September 2015 was selected for this study. The burned trees were harvested with a chainsaw, while the logs were piled with a rubber wheeled forwarder tractor. Following logging, two distinct sub-areas were identified within the logged slope based on soil disturbance: an area where the forwarder wheels had left marked trails ("trail"), and an area where such trails were absent ("control"). Three micro-plots and three plots were installed in the control area, while three micro-plots and six plots were installed in the trail area. Generally, the trail area showed greater soil compaction and larger soil surface roughness than the control area. Between October 2015 and September 2016, mean runoff was 500 mm in the control micro-plots and 50% higher in the trail micro-plots. At the plot scale, however, no differences in runoff generation were observed between the two subareas. Sediment production over the same period, however, was twice as high in the trail area than the control area, at both plot scales. In the control area, mean sediment production was 8 Mg ha-1 yr-1 at the micro-plot scale and 6 Mg ha-1 yr-1at the plot scale; in the trail area, these figures were 21 Mg ha-1 yr

  16. Exotic, native and seeded species and soil biotic community response to post-fire seedings in northern Utah

    Treesearch

    Megan Taylor

    2013-01-01

    Post-fire seeding of native species is intended to reduce weed entry, yet few studies have addressed the impacts of seeding methods on the establishment and persistence of exotic annuals. In summers of 2010 and 2011, we investigated productivity of exotic annuals across rehabilitation seedings that were established on the Scooby Wildfire site in northern Utah. The site...

  17. Drivers and implications of recent large fire years in boreal North America

    NASA Astrophysics Data System (ADS)

    Veraverbeke, S.; Rogers, B. M.; Goulden, M.; Jandt, R.; Miller, C. E.; Wiggins, E. B.; Randerson, J. T.

    2016-12-01

    High latitude ecosystems are rapidly transforming because of climate change. Boreal North America recently experienced two exceptionally large fire years: 2014 in the Northwest Territories, Canada, and 2015 in Alaska, USA. We used geospatial climate, lightning, fire, and vegetation datasets to assess the mechanisms contributing to these recent extreme years and to the causes of recent decadal-scale changes in fire dynamics. We found that the two events had a record number of lightning ignitions and unusually high levels of burning near the boreal treeline, contributing to emissions of 164 ± 32 Tg C in the Northwest Territories and 65 ± 13 Tg C in Interior Alaska. The annual number ignitions in both regions displayed a significant increasing trend since 1975, driven by an increase in lightning ignitions. We found that vapor pressure deficit (VPD) in June, lightning, and ignition events were significantly correlated on interannual timescales. Future climate-driven increases in VPD and lightning near the treeline ecotone may enable northward forest expansion within tundra ecosystems.

  18. Fire-driven alien invasion in a fire-adapted ecosystem

    USGS Publications Warehouse

    Keeley, Jon E.; Brennan, Teresa J.

    2012-01-01

    Disturbance plays a key role in many alien plant invasions. However, often the main driver of invasion is not disturbance per se but alterations in the disturbance regime. In some fire-adapted shrublands, the community is highly resilient to infrequent, high-intensity fires, but changes in the fire regime that result in shorter fire intervals may make these communities more susceptible to alien plant invasions. This study examines several wildfire events that resulted in short fire intervals in California chaparral shrublands. In one study, we compared postfire recovery patterns in sites with different prefire stand ages (3 and 24 years), and in another study we compared sites that had burned once in four years with sites that had burned twice in this period. The population size of the dominant native shrub Adenostoma fasciculatum was drastically reduced following fire in the 3-year sites relative to the 24-year sites. The 3-year sites had much greater alien plant cover and significantly lower plant diversity than the 24-year sites. In a separate study, repeat fires four years apart on the same sites showed that annual species increased significantly after the second fire, and alien annuals far outnumbered native annuals. Aliens included both annual grasses and annual forbs and were negatively correlated with woody plant cover. Native woody species regenerated well after the first fire but declined after the second fire, and one obligate seeding shrub was extirpated from two sites by the repeat fires. It is concluded that some fire-adapted shrublands are vulnerable to changes in fire regime, and this can lead to a loss of native diversity and put the community on a trajectory towards type conversion from a woody to an herbaceous system. Such changes result in alterations in the proportion of natives to non-natives, changes in functional types from deeply rooted shrubs to shallow rooted grasses and forbs, increased fire frequency due to the increase in fine fuels

  19. Fire-driven alien invasion in a fire-adapted ecosystem.

    PubMed

    Keeley, Jon E; Brennan, Teresa J

    2012-08-01

    Disturbance plays a key role in many alien plant invasions. However, often the main driver of invasion is not disturbance per se but alterations in the disturbance regime. In some fire-adapted shrublands, the community is highly resilient to infrequent, high-intensity fires, but changes in the fire regime that result in shorter fire intervals may make these communities more susceptible to alien plant invasions. This study examines several wildfire events that resulted in short fire intervals in California chaparral shrublands. In one study, we compared postfire recovery patterns in sites with different prefire stand ages (3 and 24 years), and in another study we compared sites that had burned once in four years with sites that had burned twice in this period. The population size of the dominant native shrub Adenostoma fasciculatum was drastically reduced following fire in the 3-year sites relative to the 24-year sites. The 3-year sites had much greater alien plant cover and significantly lower plant diversity than the 24-year sites. In a separate study, repeat fires four years apart on the same sites showed that annual species increased significantly after the second fire, and alien annuals far outnumbered native annuals. Aliens included both annual grasses and annual forbs and were negatively correlated with woody plant cover. Native woody species regenerated well after the first fire but declined after the second fire, and one obligate seeding shrub was extirpated from two sites by the repeat fires. It is concluded that some fire-adapted shrublands are vulnerable to changes in fire regime, and this can lead to a loss of native diversity and put the community on a trajectory towards type conversion from a woody to an herbaceous system. Such changes result in alterations in the proportion of natives to non-natives, changes in functional types from deeply rooted shrubs to shallow rooted grasses and forbs, increased fire frequency due to the increase in fine fuels

  20. Effectiveness of post-fire seeding in desert tortoise Critical Habitat following the 2005 Southern Nevada Fire Complex

    USGS Publications Warehouse

    DeFalco, Lesley; Drake, Karla K.; Scoles-Sciulla, S. J.; Bauer, Kyla L.

    2010-01-01

    In June 2005, lightning strikes ignited multiple wildfires in southern Nevada. The Southern Nevada Fire Complex burned more than 32,000 acres of designated desert tortoise Critical Habitat and an additional 403,000 acres of Mojave Desert habitat characterized as potentially suitable for the tortoise. Mortalities of desert tortoises were observed after the fires, but altered habitat is likely to prolong and magnify the impacts of wildfire on desert tortoise populations. To accelerate the re-establishment of plants commonly used by tortoises for food and shelter, the Bureau of Land Management (BLM) distributed seeds of native annual and perennial species in burned areas within desert tortoise Critical Habitat. The U.S. Geological Survey (USGS) established monitoring plots to evaluate broadcast seeding as a means to restore habitat and tortoise activity compared with natural recovery. Within the standard three-year Emergency and Stabilization Response (ESR) monitoring timeline, seeding augmented perennial seed banks by four to six-fold within a year of seed applications compared with unseeded areas. By the end of the three-year monitoring period, seedling densities of seeded perennial species were 33% higher in seeded areas than in unseeded areas, particularly for the disturbance-adapted desert globemallow (Sphaeralcea ambigua) and desert marigold (Baileya multiradiata). Seeded annuals, in contrast, did not increase significantly in seed banks or biomass production, likely due to low seeding rates of these species. Production of non-native annuals that helped carry the fires was not reduced by seeding efforts but instead was strongly correlated with site-specific rainfall, as were native annual species. The short-term vegetation changes measured in seeded areas were not yet associated with a return of tortoise activity to unburned levels. By focusing on a combination of native species that can withstand disturbance conditions, including species that are found in

  1. WRF-based fire risk modelling and evaluation for years 2010 and 2012 in Poland

    NASA Astrophysics Data System (ADS)

    Stec, Magdalena; Szymanowski, Mariusz; Kryza, Maciej

    2016-04-01

    Wildfires are one of the main ecosystems' disturbances for forested, seminatural and agricultural areas. They generate significant economic loss, especially in forest management and agriculture. Forest fire risk modeling is therefore essential e.g. for forestry administration. In August 2015 a new method of forest fire risk forecasting entered into force in Poland. The method allows to predict a fire risk level in a 4-degree scale (0 - no risk, 3 - highest risk) and consists of a set of linearized regression equations. Meteorological information is used as predictors in regression equations, with air temperature, relative humidity, average wind speed, cloudiness and rainfall. The equations include also pine litter humidity as a measure of potential fuel characteristics. All these parameters are measured routinely in Poland at 42 basic and 94 auxiliary sites. The fire risk level is estimated for a current (basing on morning measurements) or next day (basing on midday measurements). Entire country is divided into 42 prognostic zones, and fire risk level for each zone is taken from the closest measuring site. The first goal of this work is to assess if the measurements needed for fire risk forecasting may be replaced by the data from mesoscale meteorological model. Additionally, the use of a meteorological model would allow to take into account much more realistic spatial differentiation of weather elements determining the fire risk level instead of discrete point-made measurements. Meteorological data have been calculated using the Weather Research and Forecasting model (WRF). For the purpose of this study the WRF model is run in the reanalysis mode allowing to estimate all required meteorological data in a 5-kilometers grid. The only parameter that cannot be directly calculated using WRF is the litter humidity, which has been estimated using empirical formula developed by Sakowska (2007). The experiments are carried out for two selected years: 2010 and 2012. The

  2. Quantifying the effects of climate and post-fire landscape change on hydrologic processes

    NASA Astrophysics Data System (ADS)

    Steimke, A.; Han, B.; Brandt, J.; Som Castellano, R.; Leonard, A.; Flores, A. N.

    2016-12-01

    Seasonally snow-dominated, forested mountain watersheds supply water to many human populations globally. However, the timing and magnitude of water delivery from these watersheds has already and will continue to change as the climate warms. Changes in vegetation also affect the runoff response of watersheds. The largest driver of vegetation change in many mountainous regions is wildfire, whose occurrence is affected by both climate and land management decisions. Here, we quantify how direct (i.e. changes in precipitation and temperature) and indirect (i.e. changing fire regimes) effects of climate change influence hydrologic parameters such as dates of peak streamflow, annual discharge, and snowpack levels. We used the Boise River Basin, ID as a model laboratory to calculate the relative magnitude of change stemming from direct and indirect effects of climate change. This basin is relevant to study as it is well-instrumented and major drainages have experienced burning at different spatial and temporal intervals, aiding in model calibration. We built a hydrology-based integrated model of the region using a multiagent simulation framework, Envision. We used a modified HBV (Hydrologiska Byråns Vattenbalansavdelning) rainfall-runoff model and calibrated it to historic streamflow and snowpack observations. We combined a diverse set of climate projections with wildfire scenarios (low vs. high) representing two distinct intervals in the regional historic fire record. In fire simulations, we altered land cover coefficients to reflect a burned state post-fire, which decreased overall evapotranspiration rates and increased water yields. However, direct climate effects had a larger signal on annual variations of hydrologic parameters. By comparing and analyzing scenario outputs, we identified links and sensitivities between land cover and regional hydrology in the context of a changing climate, with potential implications for local land and water managers. In future

  3. Post-fire debris flow prediction in Western United States: Advancements based on a nonparametric statistical technique

    NASA Astrophysics Data System (ADS)

    Nikolopoulos, E. I.; Destro, E.; Bhuiyan, M. A. E.; Borga, M., Sr.; Anagnostou, E. N.

    2017-12-01

    Fire disasters affect modern societies at global scale inducing significant economic losses and human casualties. In addition to their direct impacts they have various adverse effects on hydrologic and geomorphologic processes of a region due to the tremendous alteration of the landscape characteristics (vegetation, soil properties etc). As a consequence, wildfires often initiate a cascade of hazards such as flash floods and debris flows that usually follow the occurrence of a wildfire thus magnifying the overall impact in a region. Post-fire debris flows (PFDF) is one such type of hazards frequently occurring in Western United States where wildfires are a common natural disaster. Prediction of PDFD is therefore of high importance in this region and over the last years a number of efforts from United States Geological Survey (USGS) and National Weather Service (NWS) have been focused on the development of early warning systems that will help mitigate PFDF risk. This work proposes a prediction framework that is based on a nonparametric statistical technique (random forests) that allows predicting the occurrence of PFDF at regional scale with a higher degree of accuracy than the commonly used approaches that are based on power-law thresholds and logistic regression procedures. The work presented is based on a recently released database from USGS that reports a total of 1500 storms that triggered and did not trigger PFDF in a number of fire affected catchments in Western United States. The database includes information on storm characteristics (duration, accumulation, max intensity etc) and other auxiliary information of land surface properties (soil erodibility index, local slope etc). Results show that the proposed model is able to achieve a satisfactory prediction accuracy (threat score > 0.6) superior of previously published prediction frameworks highlighting the potential of nonparametric statistical techniques for development of PFDF prediction systems.

  4. Variables associated with the occurrence of Ips beetles, red turpentine beetle and wood borers in live and dead ponderosa pines with post-fire injury

    Treesearch

    Jose F. Negron; Joel McMillin; Carolyn H. Sieg; James F. Fowler; Kurt K. Allen; Linda L. Wadleigh; John A. Anhold; Ken E. Gibson

    2016-01-01

    Recently, wildfires and prescribed burning have become more frequent in conifer forests of western North America. Most studies examining the impacts of insects on trees with post-fire injury have focused on contributions to tree mortality. Few studies have examined fire-caused injuries to estimate the probability of attack by insects. Scant data quantifying...

  5. Effects of salvage logging on soil properties and vegetation recovery in a fire-affected Mediterranean forest: A two year monitoring research.

    PubMed

    García-Orenes, F; Arcenegui, V; Chrenková, K; Mataix-Solera, J; Moltó, J; Jara-Navarro, A B; Torres, M P

    2017-05-15

    Post-fire management can have an additional impact on the ecosystem; in some cases, even more severe than the fire. Salvage logging (SL) is a common practice in most fire-affected areas. The management of burnt wood can determine microclimatic conditions and seriously affect soil properties. In some cases, the way of doing it, using heavy machinery, and the vulnerability of soils to erosion and degradation can make this management potentially aggressive to soil. Research was done in "Sierra de Mariola Natural Park" (E Spain). A forest fire (>500ha) occurred in July 2012. In February 2013, SL treatment was applied in a part of the affected forest. Plots for monitoring this effect were installed in this area and in a similar nearby area where no treatment was done, used as control (C). Soil samplings were done immediately after treatment and every 6months during two years. Some soil properties were analysed, including organic matter (OM) content, nitrogen (N) available phosphorous (P) basal soil respiration (BSR), microbial biomass carbon (C mic ), bulk density (BD), water repellency (WR), aggregate stability (AS) and field capacity (FC). SL treatment caused an increase in BD, a decrease of AS, FC, OM and N. In the control area, in general the soil properties remained constant across the 2years of monitoring, and the microbial parameters (BSR and C mic ), initially affected by the fire, recovered faster in C than in the SL area. Plant recovery also showed some differences between treatments. No significant differences were observed in the number of plant species recorded (richness) comparing C versus SL plots, but the number of individuals of each species (evenness) was significantly higher in C plots. In conclusion, we can affirm that for the conditions of this study case, SL had a negative effect on the soil-plant system. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Quantifying Fire Impact on Alaskan Tundra from Satellite Observations and Field Measurements

    NASA Astrophysics Data System (ADS)

    Loboda, T. V.; Chen, D.; He, J.; Jenkins, L. K.

    2017-12-01

    Wildfire is a major disturbance agent in Alaskan tundra. The frequency and extent of fire events obtained from paleo, management, and satellite records may yet underestimate the scope of tundra fire impact. Field measurements, collected within the NASA's ABoVE campaign, revealed unexpectedly shallow organic soils ( 15 cm) across all sampled sites of the Noatak valley with no significant difference between recently burned and unburned sites. In typical small and medium-sized tundra burns vegetation recovers rapidly and scars are not discernable in 30 m optical satellite imagery by the end of the first post-fire season. However, field observations indicate that vegetation and subsurface characteristics within fire scars of different ages vary across the landscape. In this study we develop linkages between fire-induced changes to tundra and satellite-based observations from optical, thermal, and microwave imagers to enable extrapolation of in-situ observations to cover the full extent of Alaskan tundra. Our results show that recent ( 30 years) fire history can be reconstructed from optical observations (R2 0.65, p<0.001) within a specific narrow temporal window or thermal signatures (R2 0.54, p < 0.001), in both cases controlled for slope and southern exposure. Using microwave SAR imagery fire history can be determined for 4 years post fire primarily due to increased soil moisture at burned sites. Field measurements suggest that the relatively quick SAR signal dissipation results from more even distribution of surface moisture through the soil column with increases in Active Layer Thickness (ALT). Similar to previous long-term field studies we find an increase in shrub fraction and shrub height within burns over time at the landscape scale; however, the strength and significance of the relationship between shrub fraction and time since fire is governed by burn severity with more severe burns predictably (p < 0.01) resulting in higher post-fire shrub cover. Although

  7. The viability of prescribed fire for mitigating the soil degradational impacts of wildfire

    NASA Astrophysics Data System (ADS)

    Shakesby, R. A.; Bento, C. P. M.; Ferreira, C. S. S.; Ferreira, A. J. D.; Stoof, C. R.; Urbanek, E.; Walsh, R. P. D.

    2012-04-01

    Prescribed (controlled) fire has become an important strategy primarily to limit the likelihood of more devastating wildfire. The considerable increase in wildfire activity in recent decades throughout the Mediterranean, and in Portugal in particular, has meant that this strategy has become increasingly popular despite inherent fears of people about fire of any sort. Despite many studies of the impact of wildfire on soil erosion and degradation, relatively little research has assessed impacts of prescribed fire on soil in Portugal or elsewhere in the Mediterranean. As part of the DESIRE research programme, this paper addresses this research gap by investigating hillslope-scale losses of soil, soil organic matter and selected nutrients before and after an experimental fire (representing a 'worst case-scenario' prescribed fire) in a shrub-vegetated catchment in central Portugal. Comparison is provided by post-fire monitoring of a nearby hillslope affected by a wildfire of moderate severity. Hillslope-scale measurements were carried out over c. 3 years using sediment fences with contributing areas of up to c. 0.5 ha. Eroded sediment was periodically removed from the fences both before and after the fire at intervals ranging from a few weeks to several months depending on rainfall characteristics and logistics. Erosion expressed as g/m2 and g/m2/mm of rainfall was determined. Figures for long-term (c. 10 years) erosion under unburnt conditions for this vegetation type were obtained from a small bounded plot and from sediment accumulating in a weir pool draining a sub-catchment within the prescribed-fire catchment. In addition, soil organic matter and selected nutrients, including K2O, P2O5 and Total N, were measured in the eroded sediment and in the pre-burn and post-burn in situ soil. The results indicate that both the wildfire and prescribed fire caused erosion that was orders of magnitude higher than for long-term plot-scale and hillslope-scale erosion recorded

  8. Quantifying sources of fine sediment supplied to post-fire debris flows using fallout radionuclide tracers

    NASA Astrophysics Data System (ADS)

    Smith, Hugh; Sheridan, Gary; Nyman, Petter; Child, David; Lane, Patrick; Hotchkis, Michael

    2013-04-01

    The supply of fine sediment and ash has been identified as an important factor contributing to the initiation of runoff-generated debris flows after fire. However, despite the significance of fines for post-fire debris flow generation, no investigations have sought to quantify sources of this material in debris flow affected catchments. In this study, we employ fallout radionuclides (Cs-137, excess Pb-210 and Pu-239,240) as tracers to measure proportional contributions of fine sediment (<10 μm) from hillslope surface and channel bank sources to levee and terminal fan deposits formed by post-fire debris flows in two forest catchments in southeastern Australia. While Cs-137 and excess Pb-210 have been widely used in sediment tracing studies, application of Pu as a tracer represents a recent development and was limited to only one catchment. The estimated range in hillslope surface contributions of fine sediment to individual debris flow deposits in each catchment was 22-69% and 32-74%, respectively. No systematic change in the source contributions to debris flow deposits was observed with distance downstream from channel initiation points. Instead, spatial variability in source contributions was largely influenced by the pattern of debris flow surges forming the deposits. Linking the sediment tracing with interpretation of depositional evidence allowed reconstruction of temporal sequences in sediment source contributions to debris flow surges. Hillslope source inputs dominated most elevated channel deposits such as marginal levees that were formed under peak flow conditions. This indicated the importance of hillslope runoff and sediment supply for debris flow generation in both catchments. In contrast, material stored within channels that was deposited during subsequent surges was predominantly channel-derived. The results demonstrate that fallout radionuclide tracers may provide unique information on the changing source contributions of fine sediment during debris

  9. Mapping post-fire forest regeneration and vegetation recovery using a combination of very high spatial resolution and hyperspectral satellite imagery

    NASA Astrophysics Data System (ADS)

    Mitri, George H.; Gitas, Ioannis Z.

    2013-02-01

    Careful evaluation of forest regeneration and vegetation recovery after a fire event provides vital information useful in land management. The use of remotely sensed data is considered to be especially suitable for monitoring ecosystem dynamics after fire. The aim of this work was to map post-fire forest regeneration and vegetation recovery on the Mediterranean island of Thasos by using a combination of very high spatial (VHS) resolution (QuickBird) and hyperspectral (EO-1 Hyperion) imagery and by employing object-based image analysis. More specifically, the work focused on (1) the separation and mapping of three major post-fire classes (forest regeneration, other vegetation recovery, unburned vegetation) existing within the fire perimeter, and (2) the differentiation and mapping of the two main forest regeneration classes, namely, Pinus brutia regeneration, and Pinus nigra regeneration. The data used in this study consisted of satellite images and field observations of homogeneous regenerated and revegetated areas. The methodology followed two main steps: a three-level image segmentation, and, a classification of the segmented images. The process resulted in the separation of classes related to the aforementioned objectives. The overall accuracy assessment revealed very promising results (approximately 83.7% overall accuracy, with a Kappa Index of Agreement of 0.79). The achieved accuracy was 8% higher when compared to the results reported in a previous work in which only the EO-1 Hyperion image was employed in order to map the same classes. Some classification confusions involving the classes of P. brutia regeneration and P. nigra regeneration were observed. This could be attributed to the absence of large and dense homogeneous areas of regenerated pine trees in the study area.

  10. Relative effects of mammal herbivory and plant spacing on seedling recruitment following fire and mining

    PubMed Central

    Parsons, Michael H; Rafferty, Christine M; Lamont, Byron B; Dods, Kenneth; Fairbanks, Meredith M

    2007-01-01

    Background There is much debate concerning which ecological constraints are the most limiting factors to seedling recruitment in disturbed communities. We provide the first comparison between selective herbivory and plant competition effects among two post-mined forest ecosystems (primary succession) and one post-fire woodland ecosystem (secondary succession). Animal exclosure assessments of nine common species across eight sites were performed for comparison within three locations separated by up to 200 km. Additionally, we asked whether pre-browsed plants differed in nutrient content between or within species in the separate systems. Results Among the nine common species, seven of these were affected by mammal herbivory while five shared a similar vulnerability to predation regardless of system. One species was limited by competition (planting density). There was a strong linear correlation between herbivore selectivity (% browsed) and impact (biomass loss) on the fertilized minesites, but not post-fire sites. Phosphorus and potassium were higher for most species in the post-mined system. Principal components analyses revealed that nutrients in shortest supply may be the most likely components of selection within each system. Among all locations, species with highest levels of phosphorus, ADF and leaf water content were often favoured, while high tannins and nitrogen content were generally selected against. Conclusion Herbivory, rather than seedling competition, was the limiting factor for plant performance among post-fire and post-mined reclamation areas. The post-fire seedlings were smaller and more water and nutrient limited, nevertheless browsing prevalence was equivalent at all locations with nearly all seedlings predated. Kangaroo density in the post-fire community declined from the beginning of the experiment, while numbers in the post-mined revegetation increased fourfold within one year. Differences in water and nutrient availability may explain why

  11. Chapter 11 - Post-hurricane fuel dynamics and implications for fire behavior (Project SO-EM-F-12-01)

    Treesearch

    Shanyue Guan; G. Geoff. Wang

    2018-01-01

    Hurricanes have long been a powerful and recurring disturbance in many coastal forest ecosystems. Intense hurricanes often produce a large amount of dead fuels in their affected forests. How the post-hurricane fuel complex changes with time, due todecomposition and management such as salvage, and its implications for fire behavior remain largely unknown....

  12. Fire and bark beetle interactions

    Treesearch

    Ken Gibson; Jose F. Negron

    2009-01-01

    Bark beetle populations are at outbreak conditions in many parts of the western United States and causing extensive tree mortality. Bark beetles interact with other disturbance agents in forest ecosystems, one of the primary being fires. In order to implement appropriate post-fire management of fire-damaged ecosystems, we need a better understanding of...

  13. 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

    NASA Astrophysics Data System (ADS)

    Ireland, Gareth; Petropoulos, George P.; Kalivas, Dionissios; Griffirths, Hywel M.; Louka, Panagiota

    2015-04-01

    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

  14. Biogeochemical legacy of prescribed fire in a giant sequoia - Mixed conifer forest: A 16-year record of watershed balances

    USGS Publications Warehouse

    Engle, D.L.; Sickman, J.O.; Moore, C.M.; Esperanza, A.M.; Melack, J.M.; Keeley, J.E.

    2008-01-01

    The effects of prescription burning on watershed balances of major ions in mixed conifer forest were examined in a 16-year paired catchment study in Sequoia National Park, California. The objective was to determine whether fire-related changes in watershed balances persist as long as estimated low-end natural fire-return intervals (???10 years), and whether cumulative net export caused by fire could deplete nutrient stocks between successive fires. Inputs (wet + dry deposition) and outputs (stream export) of N, S, Cl-, HCO3-, Ca2+, Mg2+, Na+, K+, H+, and SiO2 were measured for 7 years preceding, and 9 years following, a prescribed burn of one of the catchments. After fire, runoff coefficients increased by 7% (in dry years) to 35% (in wet years). Inorganic N was elevated in stream water for 3 years after fire. Increased export of water, SO42-, Cl-,SiO2, and base cations continued through the end of the study. Pools and processes attributed to fire led to the cumulative loss, per hectare, of 1.2 kg N, 16 kg S, 25 kg Cl-, 130 kg Ca2+, 19 kg Mg2+, 71 kg Na+, 29 kg K+ and 192 kg Si, above that predicted by prefire regression equations relating export in the paired catchments. This additional export equaled <1% of the N, up to one-third of the Ca and Mg, and up to three-fourths of the K, contained in the forest floor prior to combustion. Changes in watershed balances indicated that low-end natural fire-return intervals may prevent complete reaccumulation of several elements between fires. Copyright 2008 by the American Geophysical Union.

  15. Prediction of spatially explicit rainfall intensity-duration thresholds for post-fire debris-flow generation in the western United States

    NASA Astrophysics Data System (ADS)

    Staley, Dennis; Negri, Jacquelyn; Kean, Jason

    2016-04-01

    Population expansion into fire-prone steeplands has resulted in an increase in post-fire debris-flow risk in the western United States. Logistic regression methods for determining debris-flow likelihood and the calculation of empirical rainfall intensity-duration thresholds for debris-flow initiation represent two common approaches for characterizing hazard and reducing risk. Logistic regression models are currently being used to rapidly assess debris-flow hazard in response to design storms of known intensities (e.g. a 10-year recurrence interval rainstorm). Empirical rainfall intensity-duration thresholds comprise a major component of the United States Geological Survey (USGS) and the National Weather Service (NWS) debris-flow early warning system at a regional scale in southern California. However, these two modeling approaches remain independent, with each approach having limitations that do not allow for synergistic local-scale (e.g. drainage-basin scale) characterization of debris-flow hazard during intense rainfall. The current logistic regression equations consider rainfall a unique independent variable, which prevents the direct calculation of the relation between rainfall intensity and debris-flow likelihood. Regional (e.g. mountain range or physiographic province scale) rainfall intensity-duration thresholds fail to provide insight into the basin-scale variability of post-fire debris-flow hazard and require an extensive database of historical debris-flow occurrence and rainfall characteristics. Here, we present a new approach that combines traditional logistic regression and intensity-duration threshold methodologies. This method allows for local characterization of both the likelihood that a debris-flow will occur at a given rainfall intensity, the direct calculation of the rainfall rates that will result in a given likelihood, and the ability to calculate spatially explicit rainfall intensity-duration thresholds for debris-flow generation in recently

  16. Topographic Patterns of Mortality and Succession in the Alpine Treeline Ecotone Suggest Hydrologic Controls on Post-Fire Tree Establishment

    NASA Astrophysics Data System (ADS)

    McCaffrey, D. R.; Hopkinson, C.

    2017-12-01

    Alpine Treeline Ecotone (ATE), the transition zone between closed canopy forest and alpine tundra, is a prominent vegetation pattern in mountain regions. At continental scales, the elevation of ATE is negatively correlated with latitude and is generally explained by thermal limitations. However, at landscape scales, precipitation and moisture regimes can suppress ATE elevation below thermal limits, causing variability and patterning in ATE position. Recent studies have investigated the relative effects of hydroclimatic variables on ATE position at multiple scales, but less attention has been given to interactions between hydroclimatic variables and disturbance agents, such as fire. Observing change in the ATE at sufficient spatial resolution and temporal extent to identify correlations between topographic variables and disturbance agents has proved challenging. Recent advances in monoplotting have enabled the extraction of canopy cover information from oblique photography, at a resolution of 20 m. Using airborne lidar and repeat photography from the Mountain Legacy Project, we observed canopy cover change in West Castle Watershed (Alberta, Canada; 103 km2; 49.3° N, 114.4° W) over a 92-year period (i.e. 1914-2006). Two wildfires, occurring 1934 and 1936, affected 63% of the watershed area, providing an opportunity to contrast topographic patterns of mortality and succession in the ATE, while factoring by exposure to fire. Slope aspect was a strong predictor of mortality and succession: the frequency of mortality was four times higher in fire-exposed areas, with 72% of all mortality occurring on south- and east-facing slope aspects; the frequency of succession was balanced between fire-exposed and unexposed areas, with 66% of all succession occurred on north- and east-facing slope aspects. Given previous experiments have demonstrated that moisture limitation inhibits tree establishment, suppressing elevation of ATE below thermal growth boundaries, we hypothesize

  17. Fire-related injuries with inpatient care in Finland: a 10-year nationwide study.

    PubMed

    Haikonen, Kari; Lillsunde, Pirjo M; Lunetta, Philippe; Lounamaa, Anne; Vuola, Jyrki

    2013-06-01

    The aim of this study was to examine fire-related injuries leading to inpatient care in Finland. The Finnish National Hospital Discharge Register (2000-2009) and a sample of 222 patients from the Helsinki Burn Centre who sustained flame burns was used. During the 10-years study period, the incidence of fire-related injuries with inpatient care was approximately 5.6 per 100000 persons-years (n=295; males 74%, females 26%). Approximately three quarters involved burns and the remaining cases were mostly combustion gas poisonings. Burns declined from 5.4 in 2000 to 4.0 per 100000 person-years in 2009. The decline was accounted for by young people primarily. Socio-economic features and smoking habits differ between the injured and general population. House fire victims were mainly middle aged and older, while injures involving flammable substances, campfires, etc., were mostly associated with young people. House fires caused the worst damage in terms of Total Body Surface Area burned and inhalation burns. Significantly more people die on the scene of the incident than during the hospital care. Targeting preventive measures in particular at older people and those with a tendency for alcohol abuse and smoking could potentially reduce the burden of the most severe flame burns. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  18. Cyclic occurrence of fire and its role in carbon dynamics along an edaphic moisture gradient in longleaf pine ecosystems.

    PubMed

    Whelan, Andrew; Mitchell, Robert; Staudhammer, Christina; Starr, Gregory

    2013-01-01

    Fire regulates the structure and function of savanna ecosystems, yet we lack understanding of how cyclic fire affects savanna carbon dynamics. Furthermore, it is largely unknown how predicted changes in climate may impact the interaction between fire and carbon cycling in these ecosystems. This study utilizes a novel combination of prescribed fire, eddy covariance (EC) and statistical techniques to investigate carbon dynamics in frequently burned longleaf pine savannas along a gradient of soil moisture availability (mesic, intermediate and xeric). This research approach allowed us to investigate the complex interactions between carbon exchange and cyclic fire along the ecological amplitude of longleaf pine. Over three years of EC measurement of net ecosystem exchange (NEE) show that the mesic site was a net carbon sink (NEE = -2.48 tonnes C ha(-1)), while intermediate and xeric sites were net carbon sources (NEE = 1.57 and 1.46 tonnes C ha(-1), respectively), but when carbon losses due to fuel consumption were taken into account, all three sites were carbon sources (10.78, 7.95 and 9.69 tonnes C ha(-1) at the mesic, intermediate and xeric sites, respectively). Nonetheless, rates of NEE returned to pre-fire levels 1-2 months following fire. Consumption of leaf area by prescribed fire was associated with reduction in NEE post-fire, and the system quickly recovered its carbon uptake capacity 30-60 days post fire. While losses due to fire affected carbon balances on short time scales (instantaneous to a few months), drought conditions over the final two years of the study were a more important driver of net carbon loss on yearly to multi-year time scales. However, longer-term observations over greater environmental variability and additional fire cycles would help to more precisely examine interactions between fire and climate and make future predictions about carbon dynamics in these systems.

  19. Large-Scale Forest Fires and Resulting Alterations to the Hydrologic Cycle in the Western U.S

    NASA Astrophysics Data System (ADS)

    Carr, J.; White, A. B.; Thomson, B.

    2012-12-01

    Recent changes in climate have resulted in a decrease in precipitation and snowpack amounts and increased temperatures in the western United States. Drier and warmer conditions coupled with forest management issues have led to an increase in the frequency and size of forest fires. The 2000 Cerro Grande fire in Los Alamos, New Mexico burned over 43,000 acres and 200 structures. Eleven years later, the Las Conchas fire burned over 156,000 acres and 100 structures, including areas previously burned in 2000, and was considered the largest fire in New Mexico's history. Both fires burned ponderosa, juniper, piñon and mixed conifer forests, resulting in dramatic decreases in vegetation, changes to surface soils, and alterations to the hydrologic cycle (decreased evapotranspiration, decreased infiltration, increased runoff volume and peak discharge, and decreased time to peak discharge) in surrounding watersheds. Burned Area Emergency Response (BAER) teams need to determine the flash-flood danger quickly in order to protect residents, fire-fighters, BAER-team field personnel, and property at risk. The USGS developed an analytical method for predicting post-fire peak discharges using data collected from eight different fires throughout the western United States. We use this method to predict peak discharge in Los Alamos watersheds post-Cerro Grande and post-Las Conchas, then compare predicted to measured peak discharge. We will evaluate the effectiveness of the three methodology levels presented by the USGS, which include varying levels of data input and processing. We expect the peak discharges to be similar in magnitude; however, we will also investigate different influential factors such as burn severity, soil type, vegetation type and density, ecological connectivity, topography, pre- and post-fire weather conditions, etc., as they relate to the fires and the results seen from the measured versus the analytical method. Determining the relative influence of these

  20. Pre-fire treatment effects and post-fire forest dynamics on the Rodeo-Chediski burn area, Arizona

    Treesearch

    Barbara A. Strom

    2005-01-01

    The 2002 Rodeo-Chediski fire was the largest wildfire in Arizona history at 189,000 ha (468,000 acres), and exhibited some of the most extreme fire behavior ever seen in the Southwest. Pre-fire fuel reduction treatments of thinning, timber harvesting, and prescribed burning on the White Mountain Apache Tribal lands (WMAT) and thinning on the Apache-Sitgreaves National...

  1. One year monitoring of fire-induced effects on dissolved organic matter and nutrient dynamics under different land-use

    NASA Astrophysics Data System (ADS)

    Potthast, Karin; Meyer, Stefanie; Crecelius, Anna; Schubert, Ulrich; Michalzik, Beate

    2016-04-01

    It is supposed that the changing climate will promote extreme weather events that in turn will increase drought periods and the abundance of fire events in temperate climate regions such as Central Europe. The impact of fires on the nutrient budgets of ecosystems is highly diverse and seems to depend on the ecosystem type. For example, little is known about fire effects on water-bound organic matter (OM) and nutrient fluxes in temperate managed forest ecosystems. Fires can strongly alter the distribution (forest floor vs. mineral soil), binding forms (organic vs. inorganic) and availability (solubility by water) of OM and associated nutrients. To elucidate the effects and seasonality of low intensity fires on the mobilization of dissolved organic carbon and nutrients, an experimental ground fire was conducted in November 2014 in the Hainich region, Central Germany. In addition, differences in response patterns between two land-use types (pasture and beech forest) were investigated. Lysimeters (n=5 controls/ 5 fire-manipulated) with topsoil monoliths (0-4 cm), rainfall/throughfall samplers, littertraps as well as temperature and moisture sensors were installed on three sites of each land-use type. During the one year of monitoring (Sep14-Dec15) soil solution, rainfall, and throughfall samples were taken biweekly and analyzed for pH, dissolved and particulate organic carbon (DOC, POC) and nitrogen (DN, PN) as well as for nutrients (e.g. K, Ca, Mg, P, S). Compared to the control sites, the ground fire immediately induced a short-run release peak of DOC in both land-use types. Within two weeks these differences were muted in the post-fire period. The effect of fire was land-use specific with annual DOC fluxes of 82 and 45 kg/(ha*a) for forest and pasture sites, respectively. In contrast, nitrogen fluxes responded differently to the fire event. In the forest, a significant increase in DN concentrations was notable five months after the fire, at the beginning of the

  2. Firebrands and spotting ignition in large-scale fires

    Treesearch

    Eunmo Koo; Patrick J. Pagni; David R. Weise; John P. Woycheese

    2010-01-01

    Spotting ignition by lofted firebrands is a significant mechanism of fire spread, as observed in many largescale fires. The role of firebrands in fire propagation and the important parameters involved in spot fire development are studied. Historical large-scale fires, including wind-driven urban and wildland conflagrations and post-earthquake fires are given as...

  3. Fire and season of post-fire defoliation effects on biomass, composition and cover in mixed-grass prairie

    USDA-ARS?s Scientific Manuscript database

    North American prairies are acknowledged to have evolved with grazing following fire. Given this evolutionary fire-grazing interaction, our objective was to determine whether seasonal timing of defoliation following fire alters subsequent productivity and species composition. Following the April 201...

  4. Fire endurance research at the Forest Products Laboratory

    Treesearch

    R. H. White

    1990-01-01

    Fire endurance research activities and facilities at the FPL concern the ability of a wood member or assembly to withstand the effects of fire while acting as a fire barrier and supporting a load. Fire endurance is generally concerned with the post-flashover portion of the fire. The importance of fire endurance in fire safety is reflected in building code requirements...

  5. Tree mortality patterns following prescribed fire for Pinus and Abies across the southwestern United States

    USGS Publications Warehouse

    van Mantgem, Philip J.; Nesmith, Jonathan C. B.; Keifer, MaryBeth; Brooks, Matthew

    2012-01-01

    The reintroduction of fire to historically fire-prone forests has been repeatedly shown to reduce understory fuels and promote resistance to high severity fire. However, there is concern that prescribed fire may also have unintended consequences, such as high rates of mortality for large trees and fire-tolerant Pinus species. To test this possibility we evaluated mortality patterns for two common genera in the western US, Pinus and Abies, using observations from a national-scale prescribed fire effects monitoring program. Our results show that mortality rates of trees >50 DBH were similar for Pinus (4.6% yr-1) and Abies (4.0% yr-1) 5 years following prescribed fires across seven sites in the southwestern US. In contrast, mortality rates of trees >50 cm DBH differed between Pinus (5.7% yr-1) and Abies (9.0% yr-1). Models of post-fire mortality probabilities suggested statistically significant differences between the genera (after including differences in bark thickness), but accounting for these differences resulted in only small improvements in model classification. Our results do not suggest unusually high post-fire mortality for large trees or for Pinus relative to the other common co-occurring genus, Abies, following prescribed fire in the southwestern US.

  6. Hyperbaric and hypobaric chamber fires: a 73-year analysis.

    PubMed

    Sheffield, P J; Desautels, D A

    1997-09-01

    Fire can be catastrophic in the confined space of a hyperbaric chamber. From 1923 to 1996, 77 human fatalities occurred in 35 hyperbaric chamber fires, three human fatalities in a pressurized Apollo Command Module, and two human fatalities in three hypobaric chamber fires reported in Asia, Europe, and North America. Two fires occurred in diving bells, eight occurred in recompression (or decompression) chambers, and 25 occurred in clinical hyperbaric chambers. No fire fatalities were reported in the clinical hyperbaric chambers of North America. Chamber fires before 1980 were principally caused by electrical ignition. Since 1980, chamber fires have been primarily caused by prohibited sources of ignition that an occupant carried inside the chamber. Each fatal chamber fire has occurred in an enriched oxygen atmosphere (> 28% oxygen) and in the presence of abundant burnable material. Chambers pressurized with air (< 23.5% oxygen) had the only survivors. Information in this report was obtained from the literature and from the Undersea and Hyperbaric Medical Society's Chamber Experience and Mishap Database. This epidemiologic review focuses on information learned from critical analyses of chamber fires and how it can be applied to safe operation of hypobaric and hyperbaric chambers.

  7. An overview of prescribed fire in Arkansas and Oklahoma over the last 40 years

    Treesearch

    Roger D. Fryar

    2012-01-01

    Over the last 40 years, prescribed fire programs on National Forest lands have grown from relatively insignificant to a major emphasis area of natural resource management. During this same period, social, economic, and cultural values have greatly changed. The public's environmental awareness has likewise grown. How prescribed fire programs in Arkansas and...

  8. Post-fire tree establishment and early cohort development in conifer forests of the western Cascades of Oregon, USA

    Treesearch

    Alan J. Tepley; Frederick J. Swanson; Thomas A. Spies

    2014-01-01

    Early-seral ecosystems make important contributions to regional biodiversity by supporting high abundance and diversity of many plant and animal species that are otherwise rare or absent from closed-canopy forests. Therefore, the period of post-fire tree establishment is a key stage in forest stand and ecosystem development that can be viewed in the context of...

  9. The Missoula Fire Sciences Laboratory: A 50-year dedication to understanding wildlands and fire

    Treesearch

    Diane M. Smith

    2012-01-01

    In 1960, the USDA Forest Service established the Northern Forest Fire Laboratory (now the Missoula Fire Sciences Laboratory) to find scientific solutions for better managing the nation's wildland resources and to research ways to improve forest fire prevention and suppression. This new state-of-the-art research facility did not emerge from a vacuum, however. This...

  10. Response Mechanism: Blast/Fire Interactions.

    DTIC Science & Technology

    1983-11-01

    A WORK UNIT NUMBERS University of Notre Dame Notre Dame, IN L FEMA WU No. 2564H ItI. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE Fedqral...Fires 9 Class A Fires 10 Control by Physics or Chemistry? 11 Conments 14 EXTINCTION AND IGNITION 15 Pool Fire 15 Analysis 17 Charring Solid Fire 21...post-explosion time, although its magnitude may make the efforts to control appear futile in the wake of a nuclear attack. There is considerable

  11. RECOVER: An Automated Cloud-Based Decision Support System for Post-fire Rehabilitation Planning

    NASA Technical Reports Server (NTRS)

    Schnase, John L.; Carroll, Mark; Weber, K. T.; Brown, Molly E.; Gill, Roger L.; Wooten, Margaret; May J.; Serr, K.; Smith, E.; Goldsby, R.; hide

    2014-01-01

    RECOVER is a site-specific decision support system that automatically brings together in a single analysis environment the information necessary for post-fire rehabilitation decision-making. After a major wildfire, law requires that the federal land management agencies certify a comprehensive plan for public safety, burned area stabilization, resource protection, and site recovery. These burned area emergency response (BAER) plans are a crucial part of our national response to wildfire disasters and depend heavily on data acquired from a variety of sources. Final plans are due within 21 days of control of a major wildfire and become the guiding document for managing the activities and budgets for all subsequent remediation efforts. There are few instances in the federal government where plans of such wide-ranging scope and importance are assembled on such short notice and translated into action more quickly. RECOVER has been designed in close collaboration with our agency partners and directly addresses their high-priority decision-making requirements. In response to a fire detection event, RECOVER uses the rapid resource allocation capabilities of cloud computing to automatically collect Earth observational data, derived decision products, and historic biophysical data so that when the fire is contained, BAER teams will have a complete and ready-to-use RECOVER dataset and GIS analysis environment customized for the target wildfire. Initial studies suggest that RECOVER can transform this information-intensive process by reducing from days to a matter of minutes the time required to assemble and deliver crucial wildfire-related data.

  12. RECOVER: An Automated, Cloud-Based Decision Support System for Post-Fire Rehabilitation Planning

    NASA Astrophysics Data System (ADS)

    Schnase, J. L.; Carroll, M. L.; Weber, K. T.; Brown, M. E.; Gill, R. L.; Wooten, M.; May, J.; Serr, K.; Smith, E.; Goldsby, R.; Newtoff, K.; Bradford, K.; Doyle, C.; Volker, E.; Weber, S.

    2014-11-01

    RECOVER is a site-specific decision support system that automatically brings together in a single analysis environment the information necessary for post-fire rehabilitation decision-making. After a major wildfire, law requires that the federal land management agencies certify a comprehensive plan for public safety, burned area stabilization, resource protection, and site recovery. These burned area emergency response (BAER) plans are a crucial part of our national response to wildfire disasters and depend heavily on data acquired from a variety of sources. Final plans are due within 21 days of control of a major wildfire and become the guiding document for managing the activities and budgets for all subsequent remediation efforts. There are few instances in the federal government where plans of such wide-ranging scope and importance are assembled on such short notice and translated into action more quickly. RECOVER has been designed in close collaboration with our agency partners and directly addresses their high-priority decision-making requirements. In response to a fire detection event, RECOVER uses the rapid resource allocation capabilities of cloud computing to automatically collect Earth observational data, derived decision products, and historic biophysical data so that when the fire is contained, BAER teams will have a complete and ready-to-use RECOVER dataset and GIS analysis environment customized for the target wildfire. Initial studies suggest that RECOVER can transform this information-intensive process by reducing from days to a matter of minutes the time required to assemble and deliver crucial wildfire-related data.

  13. Spatial and Temporal Patterns of Unburned Areas within Fire Perimeters in the Northwestern United States from 1984 to 2014

    NASA Astrophysics Data System (ADS)

    Meddens, A. J.; Kolden, C.; Lutz, J. A.; Abatzoglou, J. T.; Hudak, A. T.

    2016-12-01

    Recently, there has been concern about increasing extent and severity of wildfires across the globe given rapid climate change. Areas that do not burn within fire perimeters can act as fire refugia, providing (1) protection from the detrimental effects of the fire, (2) seed sources, and (3) post-fire habitat on the landscape. However, recent studies have mainly focused on the higher end of the burn severity spectrum whereas the lower end of the burn severity spectrum has been largely ignored. We developed a spatially explicit database for 2,200 fires across the inland northwestern USA, delineating unburned areas within fire perimeters from 1984 to 2014. We used 1,600 Landsat scenes with one or two scenes before and one or two scenes after the fires to capture the unburned proportion of the fire. Subsequently, we characterized the spatial and temporal patterns of unburned areas and related the unburned proportion to interannual climate variability. The overall classification accuracy detecting unburned locations was 89.2% using a 10-fold cross-validation classification tree approach in combination with 719 randomly located field plots. The unburned proportion ranged from 2% to 58% with an average of 19% for a select number of fires. We find that using both an immediate post-fire image and a one-year post fire image improves classification accuracy of unburned islands over using just a single post-fire image. The spatial characteristics of the unburned islands differ between forested and non-forested regions with a larger amount of unburned area within non-forest. In addition, we show trends of unburned proportion related primarily to concurrent climatic drought conditions across the entire region. This database is important for subsequent analyses of fire refugia prioritization, vegetation recovery studies, ecosystem resilience, and forest management to facilitate unburned islands through fuels breaks, prescribed burning, and fire suppression strategies.

  14. The Fire Challenge: A Case Report and Analysis of Self-Inflicted Flame Injury Posted on Social Media.

    PubMed

    Avery, Andrew H; Rae, Lisa; Summitt, J Blair; Kahn, Steven Alexander

    2016-01-01

    With the advent of social media platforms such as Facebook and YouTube, online dissemination of exhibitionist videos has gained popularity. One recent disturbing trend is the "fire challenge" wherein a participant douses his or herself in a household accelerant such as isopropyl alcohol or acetone, sets him or herself ablaze, and attempts to extinguish the flames before serious burns are incurred. As expected, participants in the "fire challenge" often accidentally suffer serious burns. A 17-year-old white male was recently treated at our burn center after participating in the "fire challenge." He suffered 15% TBSA full and partial thickness burns requiring split thickness skin grafting to his abdomen. He reported lighting himself on fire because he had seen this stunt performed on the internet. A search for "fire challenge" and similar terms was conducted on YouTube (www.youtube.com). Gender and ethnicity of each participant were documented. Burn size, burn depth, and age of video participant were estimated by two attending burn surgeons evaluating YouTube videos. Results were reported with descriptive statistics. The search yielded thousands of hits, mostly home videos, compilations of stunts, and commentaries. After omitting duplicate and irrelevant videos, 50 videos were selected for the study. Of these, 13 videos included postburn footage demonstrating burn wounds of various location, size, and severity. Of these burns, the median TBSA burned was 4 ± 2.7% with a maximum size of 10%. Superficial and partial thickness burns were sustained on the torso (10/13, 77%), face (4/13, 31%), and extremities (2/13, 15%). Full thickness burns were seen in 2/13 videos. Some burn wounds were obscured by dressings. Of the 50 videos reviewed, 45/50 participants (90%) were male and 32/50 (64%) were African American with 29/50 participants (58%) estimated to be under age 20. The "fire challenge" is a popular social media phenomenon, but it can result in severe injury as seen

  15. Fire history and human activity in last 2000 years reconstructed from varved lake sediments (N Poland)

    NASA Astrophysics Data System (ADS)

    Slowinski, M. M.; Pienczewska, A.; Obremska, M.; Ott, F.; Dietze, E.; Feurdean, A.; Theuerkauf, M.; Brauer, A.

    2016-12-01

    Humans in the last two thousand years affect profound changes to ecosystem structure and function sometimes causing fire regimes. The aim of the study was to reconstruct fire history and human activity in the Tuchola Pinewoods (Northern Poland) during the last 2000 years. The robust chronology of the sediment record is based on varve counting, AMS 14C dating, 137Cs activity concentration measurements and tephrochronology (Askja AD 1875). Pollen and microscopic charcoal data were obtained from varved lake sediments at a resolution of consistently 5 years and 10 years. Data from Czechowskie lake suggest next to climate change that increased human activity was one of the main factors that influenced fire frequency (e.g. 50-450 AD and 900-1200 AD). This is particularly evident between 1776-1905 AD, when intensified forest management led to a transformation from mixed to pine dominated forests (fire-prone vegetation). Using high-resolution pollen and charcoal data we aim to identify the most probable causes of changes during the last 2000 years. Finally, we discuss the observed fire frequency and vegetation change in relation to climate changes and the socio-economic development of the area. This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analysis - ICLEA- of the Helmholtz Association and National Science Centre, Poland (grant No. 2011/01/B/ST10/07367 and 2015/17/B/ST10/03430).

  16. Post-disturbance sediment recovery: Implications for watershed resilience

    NASA Astrophysics Data System (ADS)

    Rathburn, Sara L.; Shahverdian, Scott M.; Ryan, Sandra E.

    2018-03-01

    Sediment recovery following disturbances is a measure of the time required to attain pre-disturbance sediment fluxes. Insight into the controls on recovery processes and pathways builds understanding of geomorphic resilience. We assess post-disturbance sediment recovery in three small (1.5-100 km2), largely unaltered watersheds within the northern Colorado Rocky Mountains affected by wildfires, floods, and debris flows. Disturbance regimes span 102 (floods, debris flows) to 103 years (wildfires). For all case studies, event sediment recovery followed a nonlinear pattern: initial high sediment flux during single precipitation events or high annual snowmelt runoff followed by decreasing sediment fluxes over time. Disturbance interactions were evaluated after a high-severity fire within the South Fork Cache la Poudre basin was followed by an extreme flood one year post-fire. This compound disturbance hastened suspended sediment recovery to pre-fire concentrations 3 years after the fire. Wildfires over the last 1900 YBP in the South Fork basin indicate fire recurrence intervals of 600 years. Debris flows within the upper Colorado River basin over the last two centuries have shifted the baseline of sediment recovery caused by anthropogenic activities that increased debris flow frequency. An extreme flood on North St. Vrain Creek with an impounding reservoir resulted in extreme sedimentation that led to a physical state change. We introduce an index of resilience as sediment recovery/disturbance recurrence interval, providing a relative comparison between sites. Sediment recovery and channel form resilience may be inversely related because of high or low physical complexity in streams. We propose management guidelines to enhance geomorphic resilience by promoting natural processes that maintain physical complexity. Finally, sediment connectivity within watersheds is an additional factor to consider when establishing restoration treatment priorities.

  17. Geomorphic aspects of post-fire soil erosion - Schultz Fire 2010

    Treesearch

    Ann Youberg; Karen A. Koestner; Daniel G. Neary; Peter E. Koestner

    2011-01-01

    The summer of 2010 brought wildfires and near record monsoon rains to northern Arizona, USA, which generated debris flows and floods that caused extensive damage. The human-caused Schultz Fire on the Coconino National Forest northeast of Flagstaff was the largest wildfire in Arizona during 2010, burning 6,100 ha between June 20th and 30th. Ignited by an abandoned...

  18. The increasing wildfire and post-fire debris-flow threat in western USA, and implications for consequences of climate change

    USGS Publications Warehouse

    Cannon, Susan H.; DeGraff, Jerry

    2009-01-01

    In southern California and the intermountain west of the USA, debris flows generated from recently-burned basins pose significant hazards. Increases in the frequency and size of wildfires throughout the western USA can be attributed to increases in the number of fire ignitions, fire suppression practices, and climatic influences. Increased urbanization throughout the western USA, combined with the increased wildfire magnitude and frequency, carries with it the increased threat of subsequent debris-flow occurrence. Differences between rainfall thresholds and empirical debris-flow susceptibility models for southern California and the intermountain west indicate a strong influence of climatic and geologic settings on post-fire debris-flow potential. The linkages between wildfires, debris-flow occurrence, and global warming suggests that the experiences in the western United States are highly likely to be duplicated in many other parts of the world, and necessitate hazard assessment tools that are specific to local climates and physiographies.

  19. 50 years of service: The Missoula Fire Sciences Lab

    Treesearch

    Jane Kapler Smith; Diane Smith; Colin Hardy

    2011-01-01

    In September 12, 1960, the brand new Northern Forest Fire Laboratory was dedicated in Missoula, MT. The fire lab’s mission was - and is - to improve scientific understanding of wildland fire so it can be managed more safely and effectively in the field. The first scientists to work at the fire lab initiated research that continues to be used, refined, and extended....

  20. Persistent Influences of the 2002 Hayman Fire on Stream Nitrate and Dissolved Organic Carbon

    NASA Astrophysics Data System (ADS)

    Rhoades, C.; Pierson, D. N.; Fegel, T. S., II; Chow, A. T.; Covino, T. P.

    2016-12-01

    Large, high severity wildfires alter the physical and biological conditions that determine how watersheds retain and release nutrients and regulate stream water quality. For five years after the 2002 Hayman Fire burned in Colorado conifer forests, stream nitrate concentrations and export increased steadily in watersheds with extensive high-severity burning. Stream temperature and turbidity also increased in relation to the extent of high-severity burning and remained elevated above background levels throughout the initial five year post-fire period. Our recent sampling documents that 14 years after the Hayman Fire stream nitrate remains an order of magnitude higher in extensively-burned (35-90%) compared to unburned watersheds (0.2 vs 2.8 mg L-1). Nitrate represents 83% of the total dissolved N in extensively-burned watersheds compared to 29% in unburned watersheds. In contrast, dissolved organic carbon (DOC), was highest in watersheds that burned to a moderate extent (10-20%) and lowest in those with extensive burning. Catchments with a moderate extent burned had DOC concentrations 2.5 and 1.7 times more than those with extensive burning and unburned catchments, respectively. Peak concentrations of DOC and nitrate track the rising limb of the streamflow hydrograph and reach a maximum in May, but patterns among burn extent categories were seasonally consistent. Current riparian conditions are linked to stream nitrate in burned watersheds. For example, stream nitrate increases proportionally to the extent of riparian zones with low shrub cover (R2 = 0.76). We found signs of watershed recovery compared to the initial post-fire period; stream temperature and turbidity remained elevated in extensively burned catchments, but increases were only significant during the spring season. The persistent stream nitrate concentrations as well as the relation between riparian cover and post-fire stream nitrate may help prioritize restoration planting efforts and mitigate chronic

  1. Development of fire test methods for airplane interior materials

    NASA Technical Reports Server (NTRS)

    Tustin, E. A.

    1978-01-01

    Fire tests were conducted in a 737 airplane fuselage at NASA-JSC to characterize jet fuel fires in open steel pans (simulating post-crash fire sources and a ruptured airplane fuselage) and to characterize fires in some common combustibles (simulating in-flight fire sources). Design post-crash and in-flight fire source selections were based on these data. Large panels of airplane interior materials were exposed to closely-controlled large scale heating simulations of the two design fire sources in a Boeing fire test facility utilizing a surplused 707 fuselage section. Small samples of the same airplane materials were tested by several laboratory fire test methods. Large scale and laboratory scale data were examined for correlative factors. Published data for dangerous hazard levels in a fire environment were used as the basis for developing a method to select the most desirable material where trade-offs in heat, smoke and gaseous toxicant evolution must be considered.

  2. Laboratory fire behavior measurements of chaparral crown fire

    Treesearch

    C. Sanpakit; S. Omodan; D. Weise; M Princevac

    2015-01-01

    In 2013, there was an estimated 9,900 wildland fires that claimed more than 577,000 acres of land. That same year, about 542 prescribed fires were used to treat 48,554 acres by several agencies in California. Being able to understand fires using laboratory models can better prepare individuals to combat or use fires. Our research focused on chaparral crown fires....

  3. Afforestation, subsequent forest fires and provision of hydrological services: a model-based analysis for a Mediterranean mountainous catchment

    NASA Astrophysics Data System (ADS)

    Nunes, João Pedro; Naranjo Quintanilla, Paula; Santos, Juliana; Serpa, Dalila; Carvalho-Santos, Cláudia; Rocha, João; Keizer, Jan Jacob; Keesstra, Saskia

    2017-04-01

    Mediterranean landscapes have experienced extensive abandonment and reforestation in recent decades, which should have improved the provision of hydrological services, such as flood mitigation, soil erosion protection and water quality regulation. However, these forests are fire-prone, and the post-fire increase in runoff, erosion and sediment exports could negatively affect service provision. This issue was assessed using the SWAT model for a small mountain agroforestry catchment, which was monitored between 2010 and 2014 and where some eucalypt stands burned in 2011 and were subsequently plowed for replanting. The model was calibrated and validated for streamflow, sediment yield and erosion in agricultural fields and the burnt hillslopes, showing that it can be adapted for post-fire simulation. It was then used to perform a decadal assessment of surface runoff, erosion, and sediment exports between 2004 and 2014. Results show that the fire did not noticeably affect flood mitigation but that it increased erosion by 3 orders of magnitude, which subsequently increased sediment yield. Erosion in the burnt forest during this decade was one order of magnitude above that in agricultural fields. SWAT was also used to assess different fire and land-use scenarios during the same period. Results indicate that the impacts of fire were lower without post-fire soil management, and when the fire occurred in pine forests (i.e. before the 1990s) or in shrublands (i.e. before afforestation in the 1930s). These impacts were robust to changes in post-fire weather conditions and to a lower fire frequency (20-year intervals). The results suggest that, in the long term, fire-prone forests might not provide the anticipated soil protection and water quality regulation services in wet Mediterranean regions.

  4. Post-wildfire soil erosion in the Mediterranean: Review and future research directions

    NASA Astrophysics Data System (ADS)

    Shakesby, R. A.

    2011-04-01

    Wildfires increased dramatically in frequency and extent in the European Mediterranean region from the 1960s, aided by a general warming and drying trend, but driven primarily by socio-economic changes, including rural depopulation, land abandonment and afforestation with flammable species. Published research into post-wildfire hydrology and soil erosion, beginning during the 1980s in Spain, has been followed by studies in other European Mediterranean countries together with Israel and has now attained a sufficiently large critical mass to warrant a major review. Although variations in climate, vegetation, soil, topography and fire severity cause differences in Mediterranean post-wildfire erosion, the long history of human landscape impact up to the present day is responsible for some its distinctive characteristics. This paper highlights these characteristics in reviewing wildfire impacts on hydrology, soil properties and soil erosion by water. The 'mosaic' nature of many Mediterranean landscapes (e.g. an intricate land-use pattern, abandoned terraces and tracks interrupting slopes) may explain sometimes conflicting post-fire hydrological and erosional responses at different sites and spatial scales. First-year post-wildfire soil losses at point- (average, 45-56 t ha - 1 ) and plot-scales (many < 1 t ha - 1 and the majority < 10 t ha - 1 in the first year) are similar to or even lower than those reported for fire-affected land elsewhere or other disturbed (e.g. cultivated) and natural poorly-vegetated (e.g. badlands, rangeland) land in the Mediterranean. The few published losses at larger-scales (hillslope and catchment) are variable. Thin soil and high stone content can explain supply-limited erosion preceding significant protection by recovering vegetation. Peak erosion can sometimes be delayed for years, largely through slow vegetation recovery and temporal variability of erosive storms. Preferential removal of organic matter and nutrients in the commonly thin

  5. Quantifying sources of fine sediment supplied to post-fire debris flows using fallout radionuclide tracers

    NASA Astrophysics Data System (ADS)

    Smith, Hugh G.; Sheridan, Gary J.; Nyman, Petter; Child, David P.; Lane, Patrick N. J.; Hotchkis, Michael A. C.; Jacobsen, Geraldine E.

    2012-02-01

    Fine sediment supply has been identified as an important factor contributing to the initiation of runoff-generated debris flows after fire. However, despite the significance of fines for post-fire debris flow generation, no investigations have sought to quantify sources of this material in debris flow affected catchments. In this study, we employ fallout radionuclides ( 137Cs, 210Pb ex and 239,240Pu) as tracers to measure proportional contributions of fine sediment (< 10 μm) from hillslope surface and channel bank sources to levee and terminal fan deposits formed by post-fire debris flows in two forest catchments in southeastern Australia. While 137Cs and 210Pb ex have been widely used in sediment tracing studies, application of Pu as a tracer represents a recent development and was limited to only one catchment. The ranges in estimated proportional hillslope surface contributions of fine sediment to individual debris flow deposits in each catchment were 22-69% and 32-74%. The greater susceptibility of 210Pb ex to apparent reductions in the ash content of channel deposits relative to hillslope sources resulted in its exclusion from the final analysis. No systematic change in the proportional source contributions to debris flow deposits was observed with distance downstream from channel initiation points. Instead, spatial variability in source contributions was largely influenced by the pattern of debris flow surges forming the deposits. Linking the tracing analysis with interpretation of depositional evidence allowed reconstruction of temporal sequences in sediment source contributions to debris flow surges. Hillslope source inputs dominated most elevated channel deposits such as marginal levees that were formed under peak flow conditions. This indicated the importance of hillslope runoff and fine sediment supply for debris flow generation in both catchments. In contrast, material stored within channels that was deposited during subsequent surges was predominantly

  6. Fire

    Treesearch

    John R. Jones; Norbert V. DeByle

    1985-01-01

    In some areas, many aspen stands are all the same age, dating from a single great fire or a year of widespread fires (fig. 1). The 1879 fire in the Jackson Hole region of Wyoming (Loope and Gruell 1973) and the 1904 fires in Arizona's White Mountains (Kallander 1969) are examples. Choate (1966) found that almost all aspen stands in New Mexico were even-aged, many...

  7. The Response of Tundra to Biophysical Changes Ten Years Following the Anaktuvuk River Fire, Arctic Foothills, Alaska.

    NASA Astrophysics Data System (ADS)

    Jones, B. M.; Miller, E. A.; Jandt, R.; Baughman, C. A.

    2017-12-01

    Ten years following a large and severe wildfire in the arctic foothills of the Brooks Range, Alaska, tundra is experiencing rapid biophysical changes. Plant communities are responding to primary disturbance by fire but also to ground-ice melt, terrain subsidence, and apparent increase in soil drainage or evapotranspiration.The Anaktuvuk River Fire burned about 104,000 ha in 2007, spreading over broad ranges in soils, topography, hydrography, and permafrost features. Fourteen marked transects were measured between 2008-2011 and again in 2017 for cover of ground-layer vegetation, tall shrub abundance, thaw depth, and soil properties. A complementary set of 11 reference transects surrounding the burn was also sampled.We observed much higher rates of thermokarst inside the burn than out. Even low severity burn areas experienced noticeable thaw subsidence. Mean annual ground temperature at 1 m depth has warmed 1.5°C relative to unburned tundra. In cases ice wedge troughs have deepened by more than 1 m in areas underlain by yedoma soils. Troughs were characterized by cracking soil and slumping tussocks, often into ponded water. Troughs and degraded ice features appear to be draining adjacent polygon centers leading to a general drying of the tundra. Tussockgrasses inside the burn continue to grow and flower vigorously, suggesting a continued flush of soil nutrients. Post-fire accumulation of organic material is generally <5 cm of mostly moss and plant litter. Species of tall willow are responding by increases in stature and colonization of thermokarst areas.Other studies suggest that tundra north of the Brooks Range is responding to climate change with widespread expansion of and dominance by tall shrubs. Our observations from the Anaktuvuk River Burn, as well as at several other older burns, suggest that fire greatly accelerates this succession. Records and observations suggest that lightning and ignitions are becoming more frequent north of the Brooks Range

  8. Does fire severity influence shrub resprouting after spring prescribed burning?

    NASA Astrophysics Data System (ADS)

    Fernández, Cristina; Vega, José A.; Fonturbel, Teresa

    2013-04-01

    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.

  9. Exploring Model Error through Post-processing and an Ensemble Kalman Filter on Fire Weather Days

    NASA Astrophysics Data System (ADS)

    Erickson, Michael J.

    The proliferation of coupling atmospheric ensemble data to models in other related fields requires a priori knowledge of atmospheric ensemble biases specific to the desired application. In that spirit, this dissertation focuses on elucidating atmospheric ensemble model bias and error through a variety of different methods specific to fire weather days (FWDs) over the Northeast United States (NEUS). Other than a handful of studies that use models to predict fire indices for single fire seasons (Molders 2008, Simpson et al. 2014), an extensive exploration of model performance specific to FWDs has not been attempted. Two unique definitions for FWDs are proposed; one that uses pre-existing fire indices (FWD1) and another from a new statistical fire weather index (FWD2) relating fire occurrence and near-surface meteorological observations. Ensemble model verification reveals FWDs to have warmer (> 1 K), moister (~ 0.4 g kg-1) and less windy (~ 1 m s-1) biases than the climatological average for both FWD1 and FWD2. These biases are not restricted to the near surface but exist through the entirety of the planetary boundary layer (PBL). Furthermore, post-processing methods are more effective when previous FWDs are incorporated into the statistical training, suggesting that model bias could be related to the synoptic flow pattern. An Ensemble Kalman Filter (EnKF) is used to explore the effectiveness of data assimilation during a period of extensive FWDs in April 2012. Model biases develop rapidly on FWDs, consistent with the FWD1 and FWD2 verification. However, the EnKF is effective at removing most biases for temperature, wind speed and specific humidity. Potential sources of error in the parameterized physics of the PBL are explored by rerunning the EnKF with simultaneous state and parameter estimation (SSPE) for two relevant parameters within the ACM2 PBL scheme. SSPE helps to reduce the cool temperature bias near the surface on FWDs, with the variability in parameter

  10. Is fire a long term sink or source of atmospheric carbon? A comprehensive evaluation of a boreal forest fire

    NASA Astrophysics Data System (ADS)

    Santin, C.; Doerr, S. H.; Preston, C.; Bryant, R.

    2012-12-01

    Fires lead to a rapid release of carbon (C) from forest and other fire-prone ecosystems, emitting important quantities of C to the atmosphere. Every year 300-600 Mill. ha burn around the globe, generating CO2 emissions equivalent to half of the current annual global from fossil fuel combustion. Over the longer-term vegetation fires are widely considered as 'net zero Carbon (C) emission events', because C emissions from fires, excluding those associated with deforestation, are balanced by C uptake by regenerating vegetation. This 'zero C emission' scenario, however, may be flawed, as it does not consider the role of pyrogenic C (PyC). During fire, some of the fuel is transformed into PyC (i.e. charcoal, black C, soot), which is characterized by an enhanced recalcitrance and a longer mean residence time in the environment than its 'fresh' precursors. Therefore, after complete regeneration of the vegetation, the PyC generated represents an additional longer-term C pool and, hence, recurring fire-regrowth cycles could be considered as a 'net sink of atmospheric C'. To test the validity of this hypothesis, and to estimate how quantitatively important this PyC pool might be, accurate data on PyC production with respect to the fuel combusted are needed. Unfortunately, detailed quantification of fuel prior to fire is normally only available for prescribed and experimental fires, which are usually of low-intensity and therefore not representative of higher-intensity wildfires. Furthermore, what little data is available is usually based on only a specific fraction of the PyC present following burning rather than the whole range of PyC products and stores (i.e. PyC in soil, ash, downed wood and standing vegetation). The FireSmart project (Ft. Providence, NWT, Canada, June 2012) provided the ideal framework to address this research gap. This experimental fire reproduced wildfire conditions in boreal forest, i.e. stand-replacing crown fire and, at the same time, allowed i) pre-fire

  11. Cyclic Occurrence of Fire and Its Role in Carbon Dynamics along an Edaphic Moisture Gradient in Longleaf Pine Ecosystems

    PubMed Central

    Whelan, Andrew; Mitchell, Robert; Staudhammer, Christina; Starr, Gregory

    2013-01-01

    Fire regulates the structure and function of savanna ecosystems, yet we lack understanding of how cyclic fire affects savanna carbon dynamics. Furthermore, it is largely unknown how predicted changes in climate may impact the interaction between fire and carbon cycling in these ecosystems. This study utilizes a novel combination of prescribed fire, eddy covariance (EC) and statistical techniques to investigate carbon dynamics in frequently burned longleaf pine savannas along a gradient of soil moisture availability (mesic, intermediate and xeric). This research approach allowed us to investigate the complex interactions between carbon exchange and cyclic fire along the ecological amplitude of longleaf pine. Over three years of EC measurement of net ecosystem exchange (NEE) show that the mesic site was a net carbon sink (NEE = −2.48 tonnes C ha−1), while intermediate and xeric sites were net carbon sources (NEE = 1.57 and 1.46 tonnes C ha−1, respectively), but when carbon losses due to fuel consumption were taken into account, all three sites were carbon sources (10.78, 7.95 and 9.69 tonnes C ha−1 at the mesic, intermediate and xeric sites, respectively). Nonetheless, rates of NEE returned to pre-fire levels 1–2 months following fire. Consumption of leaf area by prescribed fire was associated with reduction in NEE post-fire, and the system quickly recovered its carbon uptake capacity 30–60 days post fire. While losses due to fire affected carbon balances on short time scales (instantaneous to a few months), drought conditions over the final two years of the study were a more important driver of net carbon loss on yearly to multi-year time scales. However, longer-term observations over greater environmental variability and additional fire cycles would help to more precisely examine interactions between fire and climate and make future predictions about carbon dynamics in these systems. PMID:23335986

  12. Epicormic resprouting in fire-prone ecosystems

    USGS Publications Warehouse

    Pausas, Juli G.; Keeley, Jon E.

    2017-01-01

    Many plants resprout from basal buds after disturbance, and this is common in shrublands subjected to high-intensity fires. However, resprouting after fire from epicormic (stem) buds is globally far less common. Unlike basal resprouting, post-fire epicormic resprouting is a key plant adaptation for retention of the arborescent skeleton after fire, allowing rapid recovery of the forest or woodland and leading to greater ecosystem resilience under recurrent high-intensity fires. Here we review the biogeography of epicormic resprouting, the mechanisms of protection, the fire regimes where it occurs, and the evolutionary drivers that shaped this trait. We propose that epicormic resprouting is adaptive in ecosystems with high fire frequency and relatively high productivity, at moderate–high fire intensities.

  13. Aircraft fires, smoke toxicity, and survival : an overview.

    DOT National Transportation Integrated Search

    1995-02-01

    In-flight fires in modern aircraft are rare, but post-crash fires do occur. Cabin occupants frequently survive initial forces of such crashes but are incapacitated from smoke inhalation. According to an international study, there were 95 fire-related...

  14. Inaja Fire - 1956, Pine Hills Fire - 1967...similar, yet different

    Treesearch

    Mark J. Schroeder; Bernadine B. Taylor

    1968-01-01

    Two fires burned in the same area in southern California under nearly similar weather conditions, 11 years apart. Yet the Inaja fire of 1956 was much more disastrous than the Pine Hills fire of 1967. The earlier fire claimed 11 lives, and covered an area five times larger than the 1967 fire. Differences in fuels, topography, fire behavior, fire-control action, and...

  15. Using unplanned fires to help suppressing future large fires in Mediterranean forests.

    PubMed

    Regos, Adrián; Aquilué, Núria; Retana, Javier; De Cáceres, Miquel; Brotons, Lluís

    2014-01-01

    Despite the huge resources invested in fire suppression, the impact of wildfires has considerably increased across the Mediterranean region since the second half of the 20th century. Modulating fire suppression efforts in mild weather conditions is an appealing but hotly-debated strategy to use unplanned fires and associated fuel reduction to create opportunities for suppression of large fires in future adverse weather conditions. Using a spatially-explicit fire-succession model developed for Catalonia (Spain), we assessed this opportunistic policy by using two fire suppression strategies that reproduce how firefighters in extreme weather conditions exploit previous fire scars as firefighting opportunities. We designed scenarios by combining different levels of fire suppression efficiency and climatic severity for a 50-year period (2000-2050). An opportunistic fire suppression policy induced large-scale changes in fire regimes and decreased the area burnt under extreme climate conditions, but only accounted for up to 18-22% of the area to be burnt in reference scenarios. The area suppressed in adverse years tended to increase in scenarios with increasing amounts of area burnt during years dominated by mild weather. Climate change had counterintuitive effects on opportunistic fire suppression strategies. Climate warming increased the incidence of large fires under uncontrolled conditions but also indirectly increased opportunities for enhanced fire suppression. Therefore, to shift fire suppression opportunities from adverse to mild years, we would require a disproportionately large amount of area burnt in mild years. We conclude that the strategic planning of fire suppression resources has the potential to become an important cost-effective fuel-reduction strategy at large spatial scale. We do however suggest that this strategy should probably be accompanied by other fuel-reduction treatments applied at broad scales if large-scale changes in fire regimes are to be

  16. In situ measurements of post-fire debris flows in southern California: Comparisons of the timing and magnitude of 24 debris-flow events with rainfall and soil moisture conditions

    USGS Publications Warehouse

    Kean, J.W.; Staley, D.M.; Cannon, S.H.

    2011-01-01

    Debris flows often occur in burned steeplands of southern California, sometimes causing property damage and loss of life. In an effort to better understand the hydrologic controls on post-fire debris-flow initiation, timing and magnitude, we measured the flow stage, rainfall, channel bed pore fluid pressure and hillslope soil-moisture accompanying 24 debris flows recorded in five different watersheds burned in the 2009 Station and Jesusita Fires (San Gabriel and Santa Ynez Mountains). The measurements show substantial differences in debris-flow dynamics between sites and between sequential events at the same site. Despite these differences, the timing and magnitude of all events were consistently associated with local peaks in short duration (< = 30 min) rainfall intensity. Overall, debris-flow stage was best cross-correlated with time series of 5-min rainfall intensity, and lagged the rainfall by an average of just 5 min. An index of debris-flow volume was also best correlated with short-duration rainfall intensity, but found to be poorly correlated with storm cumulative rainfall and hillslope soil water content. Post-event observations of erosion and slope stability modeling suggest that the debris flows initiated primarily by processes related to surface water runoff, rather than shallow landslides. By identifying the storm characteristics most closely associated with post-fire debris flows, these measurements provide valuable guidance for warning operations and important constraints for developing and testing models of post-fire debris flows. copyright. 2011 by the American Geophysical Union.

  17. Effects of Fire on Understory Vegetation Communities in Siberian Boreal Forests and Alaskan Tundra

    NASA Astrophysics Data System (ADS)

    Pena, H., III; Alexander, H. D.; Natali, S.; Loranty, M. M.; Holmes, R. M.; Mack, M. C.; Schade, J. D.; Mann, P. J.; Davydov, S. P.; Frey, B.; Zimov, N.; Jardine, L. E.

    2017-12-01

    Fire is an important disturbance in Arctic ecosystems that is increasing in frequency and severity as a result of climate warming. Fire alters the landscape, changes soil conditions, and influences vegetation regrowth, favoring early-successional plants and those with well-established root systems capable of surviving fire. Post-fire vegetation establishment contributes to the recovery of the soil organic layer (SOL), which insulates the soil and protects soil and permafrost carbon pools. In order to better understand successional dynamics following fire in the Arctic we assessed the short-(years) and long-(decades) term effects of fire on vegetation communities, SOL depth, and thaw depth across fire-affected sites located in two regions of the Arctic- a 76-year old fire scar in a larch forest in Siberia near Cherskiy, Russia, and a 2-year old fire scar in tundra in the Yukon-Kuskokwim Delta, Alaska. We measured species diversity, plant carbon (C) pools, SOL conditions and NDVI at both study areas. As expected, there was a decline in vegetation C pools following fire in Alaskan tundra, and as a result of higher severity fire in Siberian boreal forests. Two years following fire in Alaskan tundra, vegetation C pools decreased six-fold from 600 g C m-2 at unburned areas, to 100 g C m-2 at the 2015 burn areas. In larch forests, understory C pools were three-times lower in stands with high intensity fires (135 g C m-2) compared to those with low intensity fires (415 g C m-2), due to the absence of dwarf birch (Betula nana). Our results illustrate how fire influences vegetation at both early and later stages of succession, which can have cascading effects on SOL development and permafrost integrity, with the potential for release of large C stocks that may further exacerbate climate warming.

  18. Cambial injury in lodgepole pine (Pinus contorta): mountain pine beetle vs fire.

    PubMed

    Arbellay, Estelle; Daniels, Lori D; Mansfield, Shawn D; Chang, Alice S

    2017-12-01

    Both mountain pine beetle (MPB) Dendroctonus ponderosae Hopkins and fire leave scars with similar appearance on lodgepole pine Pinus contorta Dougl. ex Loud. var. latifolia Engelm. that have never been compared microscopically, despite the pressing need to determine the respective effects of MPB and fire injury on tree physiology. We analysed changes in wood formation in naturally caused scars on lodgepole pine, and tested the hypotheses that (i) MPB and fire injury elicit distinct anomalies in lodgepole pine wood and (ii) anomalies differ in magnitude and/or duration between MPB and fire. Mountain pine beetle and fire injury reduced radial growth in the first year post-injury. Otherwise, radial growth and wood density increased over more than 10 years in both MPB and fire scars. We found that the general increase in radial growth was of greater magnitude (up to 27%) and of longer duration (up to 5 years) in fire scars compared with MPB scars, as shown in earlywood width. We also observed that the increase in latewood density was of greater magnitude (by 12%) in MPB scars, but of longer duration (by 4 years) in fire scars. Crystallinity decreased following MPB and fire injury, while microfibril angle increased. These changes in fibre traits were of longer duration (up to 4 years) in MPB scars compared with fire scars, as shown in microfibril angle. We found no significant changes in carbon and nitrogen concentrations. In conclusion, we stress that reduced competition and resistance to cavitation play an important role alongside cambial injury in influencing the type and severity of changes. In addition, more research is needed to validate the thresholds introduced in this study. Our findings serve as a foundation for new protocols to distinguish between bark beetle and fire disturbance, which is essential for improving our knowledge of historical bark beetle and fire regimes, and their interactions. © The Author 2017. Published by Oxford University Press. All

  19. Fire, Carbon and Climate Change in Boreal Forests

    NASA Astrophysics Data System (ADS)

    Flannigan, M. D.; Amiro, B. D.; Logan, K. A.

    2005-12-01

    Disturbances are the major stand-renewing agents for much of the circumboreal forest. In Canada, fire has received much of the attention in carbon cycle science because it affects about 3 million ha of Canadian forest annually, impacts air quality, and can threaten life, property and infrastructure. Fire affects the carbon balance through three processes. First, carbon and other greenhouse gases are emitted to the atmosphere during the combustion process. We estimate this to average about 27 Tg C/year in Canada over the past 40 years, which is close to 20% of industrial carbon emissions. However, in some years this can exceed 100 Tg C. Efforts are underway to estimate global fire activity and greenhouse gas emissions using observations, remote sensing and modelling. The second process is the decomposition of fire-killed vegetation. This forms a pool of coarse woody debris that can take decades to decompose, or can be quite rapid, depending on the post-fire environment. The third process is succession of vegetation following fire, a dynamic process that involves the interplay among species establishment and competition. Weather and climate affects all of these processes. Estimates of the future environment indicate that much of boreal Canada will experience warmer and drier conditions, although there will be regional differences and transient effects. The projections suggest that we may experience a doubling of area burned over the next century because of anthropogenic climate changes. This may have further implications to the global carbon budget by increasing atmospheric carbon dioxide concentrations. This increase in fire activity may lead to a positive feedback cycle with the increased release of greenhouse gases. A run-away scenario is unlikely because young successional boreal vegetation often does not burn as readily and would limit the positive feedback cycle. Also, changes to the forest composition following fire increases surface albedo and alters the

  20. Cardiorespiratory hospitalizations associated with smoke exposure during the 1997, Southeast Asian forest fires.

    PubMed

    Mott, Joshua A; Mannino, David M; Alverson, Clinton J; Kiyu, Andrew; Hashim, Jamilah; Lee, Tzesan; Falter, Kenneth; Redd, Stephen C

    2005-01-01

    We investigated the cardiorespiratory health effects of smoke exposure from the 1997 Southeast Asian Forest Fires among persons who were hospitalized in the region of Kuching, Malaysia. We selected admissions to seven hospitals in the Kuching region from a database of all hospital admissions in the state of Sarawak during January 1, 1995 and December 31, 1998. For several cardiorespiratory disease classifications we used Holt-Winters time-series analyses to determine whether the total number of monthly hospitalizations during the forest fire period (August 1 to October 31, 1997), or post-fire period (November 1, 1997 to December 31, 1997) exceeded forecasted estimates established from a historical baseline period of January 1, 1995 to July 31, 1997. We also identified age-specific cohorts of persons whose members were admitted for specific cardiorespiratory problems during January 1 to July 31 of each year (1995--1997). We compared Kaplan-Meier survival curves of time to first readmission for the 1997 cohorts (exposed to the forest fire smoke) with the survival curves for the 1995 and 1996 cohorts (not exposed, pre-fire cohorts). The time-series analyses indicated that statistically significant fire-related increases were observed in respiratory hospitalizations, specifically those for chronic obstructive pulmonary disease (COPD) and asthma. The survival analyses indicated that persons over age 65 years with previous hospital admissions for any cause (chi2(1df) = 5.98, p = 0.015), any cardiorespiratory disease (chi2(1df) = 5.3, p = 0.02), any respiratory disease (chi2(1df) = 7.8, p = 0.005), or COPD (chi2(1df) = 3.9, p = 0.047), were significantly more likely to be rehospitalized during the follow-up period in 1997 than during the follow-up periods in the pre-fire years of 1995 or 1996. The survival functions of the exposed cohorts resumed similar trajectories to unexposed cohorts during the post-fire period of November 1, 1997 to December 31, 1998. Communities

  1. One thousand years of fires: Integrating proxy and model data

    USGS Publications Warehouse

    Kehrwald, Natalie; Aleman, Julie C.; Coughlan, Michael; Courtney Mustaphi, Colin J.; Githumbi, Esther N.; Magi, Brian I.; Marlon, Jennifer R.; Power, Mitchell J.

    2016-01-01

    The expected increase in fire activity in the upcoming decades has led to a surge in research trying to understand their causes, the factors that may have influenced similar times of fire activity in the past, and the implications of such fire activity in the future. Multiple types of complementary data provide information on the impacts of current fires and the extent of past fires. The wide array of data encompasses different spatial and temporal resolutions (Figure 1) and includes fire proxy information such as charcoal and tree ring fire scars, observational records, satellite products, modern emissions data, fire models within global land cover and vegetation models, and sociodemographic data for modeling past human land use and ignition frequency. Any single data type is more powerful when combined with another source of information. Merging model and proxy data enables analyses of how fire activity modifies vegetation distribution, air and water quality, and proximity to cities; these analyses in turn support land management decisions relating to conservation and development.

  2. Object-based Forest Fire Analysis for Pedrógão Grande Fire Using Landsat 8 OLI and Sentinel-2A Imagery

    NASA Astrophysics Data System (ADS)

    Tonbul, H.; Kavzoglu, T.

    2017-12-01

    Forest fires are among the most important natural disasters with the damage to the natural habitat and human-life. Mapping damaged forest fires is crucial for assessing ecological effects caused by fire, monitoring land cover changes and modeling atmospheric and climatic effects of fire. In this context, satellite data provides a great advantage to users by providing a rapid process of detecting burning areas and determining the severity of fire damage. Especially, Mediterranean ecosystems countries sets the suitable conditions for the forest fires. In this study, the determination of burnt areas of forest fire in Pedrógão Grande region of Portugal occurred in June 2017 was carried out using Landsat 8 OLI and Sentinel-2A satellite images. The Pedrógão Grande fire was one of the largest fires in Portugal, more than 60 people was killed and thousands of hectares were ravaged. In this study, four pairs of pre-fire and post-fire top of atmosphere (TOA) and atmospherically corrected images were utilized. The red and near infrared (NIR) spectral bands of pre-fire and post-fire images were stacked and multiresolution segmentation algorithm was applied. In the segmentation processes, the image objects were generated with estimated optimum homogeneity criteria. Using eCognition software, rule sets have been created to distinguish unburned areas from burned areas. In constructing the rule sets, NDVI threshold values were determined pre- and post-fire and areas where vegetation loss was detected using the NDVI difference image. The results showed that both satellite images yielded successful results for burned area discrimination with a very high degree of consistency in terms of spatial overlap and total burned area (over 93%). Object based image analysis (OBIA) was found highly effective in delineation of burnt areas.

  3. Can anthropic fires affect epigaeic and hypogaeic Cerrado ant (Hymenoptera: Formicidae) communities in the same way?

    PubMed

    Canedo-Júnior, Ernesto de Oliveira; Cuissi, Rafael Gonçalves; Nelson Henrique de Almeida, Curi; Demetrio, Guilherme Ramos; Lasmar, Chaim José; Malves, Kira

    2016-03-01

    Fire occurrences are a common perturbation in Cerrado ecosystems, and may differently impact the local biodiversity. Arthropods are one of the taxa affected by fires, and among them, ants are known as good bioindicators. We aimed to evaluate the effect of anthropic fires on epigaeic and hypogaeic ant communities (species richness and composition) in Cerrado areas with different post-fire event recovery periods. We conducted the study in four Cerrado areas during two weeks of 2012 dry season: one unburned and three at different post-fire times (one month, one and two years). We sampled ants with pitfall traps in epigaeic and hypogaeic microhabitats. We collected 71 ant morpho-species from 25 genera. In the epigaeic microhabitat we sampled 56 morpho-species and 42 in the hypogaeic microhabitat. The area with the shortest recovery time presented lower epigaeic ant species richness (4.3 ± 2.00) in comparison to the other areas (8.1 ± 2.68 species on one year area; 10.3 ± 2.66 species on two years area; 10.4 ± 2.31 species on control area), but recovery time did not affect hypogaeic ant species richness. Regarding ant species composition, fire did not directly affect hypogaeic ant species, which remained the same even one month after fire event. However, two years were not enough to reestablish ant species composition in both microhabitats in relation to our control group samples. Our study is the first to assess anthropic fire effects upon epigaeic and hypogaeic ants communities; highlighting the importance of evaluating different microhabitats, to more accurately detect the effects of anthropic disturbances in biological communities. We concluded that ant communities are just partially affected by fire occurrences, and epigaeic assemblages are the most affected ones in comparison to hypogaeic ants. Furthermore the study provides knowledge to aid in the creation of vegetation management programs that allow Cerrado conservation.

  4. Characterizing the primary material sources and dominant erosional processes for post-fire debris-flow initiation in a headwater basin using multi-temporal terrestrial laser scanning data

    USGS Publications Warehouse

    Staley, Dennis M.; Waslewicz, Thad A.; Kean, Jason W.

    2014-01-01

    Wildfire dramatically alters the hydrologic response of a watershed such that even modest rainstorms can produce hazardous debris flows. Relative to shallow landslides, the primary sources of material and dominant erosional processes that contribute to post-fire debris-flow initiation are poorly constrained. Improving our understanding of how and where material is eroded from a watershed during a post-fire debris-flow requires (1) precise measurements of topographic change to calculate volumetric measurements of erosion and deposition, and (2) the identification of relevant morphometrically defined process domains to spatially constrain these measurements of erosion and deposition. In this study, we combine the morphometric analysis of a steep, small (0.01 km2) headwater drainage basin with measurements of topographic change using high-resolution (2.5 cm) multi-temporal terrestrial laser scanning data made before and after a post-fire debris flow. The results of the morphometric analysis are used to define four process domains: hillslope-divergent, hillslope-convergent, transitional, and channelized incision. We determine that hillslope-divergent and hillslope-convergent process domains represent the primary sources of material over the period of analysis in the study basin. From these results we conclude that raindrop-impact induced erosion, ravel, surface wash, and rilling are the primary erosional processes contributing to post-fire debris-flow initiation in the small, steep headwater basin. Further work is needed to determine (1) how these results vary with increasing drainage basin size, (2) how these data might scale upward for use with coarser resolution measurements of topography, and (3) how these results change with evolving sediment supply conditions and vegetation recovery.

  5. Alterations caused to soil organic matter by post-fire rehabilitation actions in a pine forest from doñana national park (southwest Spain)

    NASA Astrophysics Data System (ADS)

    González-Pérez, José A.; Jiménez-Morillo, Nicasio T.; Jordán, Antonio; Zavala, Lorena M.; Granged, Arturo J. P.; González-Vila, Francisco J.

    2016-04-01

    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

  6. Fire suppression in human-crew spacecraft

    NASA Technical Reports Server (NTRS)

    Friedman, Robert; Dietrich, Daniel L.

    1991-01-01

    Fire extinguishment agents range from water and foam in early-design spacecraft (Halon 1301 in the present Shuttle) to carbon dioxide proposed for the Space Station Freedom. The major challenge to spacecraft fire extinguishment design and operations is from the micro-gravity environment, which minimizes natural convection and profoundly influences combustion and extinguishing agent effectiveness, dispersal, and post-fire cleanup. Discussed here are extinguishment in microgravity, fire-suppression problems anticipated in future spacecraft, and research needs and opportunities.

  7. Using Unplanned Fires to Help Suppressing Future Large Fires in Mediterranean Forests

    PubMed Central

    Regos, Adrián; Aquilué, Núria; Retana, Javier; De Cáceres, Miquel; Brotons, Lluís

    2014-01-01

    Despite the huge resources invested in fire suppression, the impact of wildfires has considerably increased across the Mediterranean region since the second half of the 20th century. Modulating fire suppression efforts in mild weather conditions is an appealing but hotly-debated strategy to use unplanned fires and associated fuel reduction to create opportunities for suppression of large fires in future adverse weather conditions. Using a spatially-explicit fire–succession model developed for Catalonia (Spain), we assessed this opportunistic policy by using two fire suppression strategies that reproduce how firefighters in extreme weather conditions exploit previous fire scars as firefighting opportunities. We designed scenarios by combining different levels of fire suppression efficiency and climatic severity for a 50-year period (2000–2050). An opportunistic fire suppression policy induced large-scale changes in fire regimes and decreased the area burnt under extreme climate conditions, but only accounted for up to 18–22% of the area to be burnt in reference scenarios. The area suppressed in adverse years tended to increase in scenarios with increasing amounts of area burnt during years dominated by mild weather. Climate change had counterintuitive effects on opportunistic fire suppression strategies. Climate warming increased the incidence of large fires under uncontrolled conditions but also indirectly increased opportunities for enhanced fire suppression. Therefore, to shift fire suppression opportunities from adverse to mild years, we would require a disproportionately large amount of area burnt in mild years. We conclude that the strategic planning of fire suppression resources has the potential to become an important cost-effective fuel-reduction strategy at large spatial scale. We do however suggest that this strategy should probably be accompanied by other fuel-reduction treatments applied at broad scales if large-scale changes in fire regimes are

  8. Forest Understory Fire in the Brazilian Amazon in ENSO and Non-ENSO Years: Area Burned and Committed Carbon Emissions

    NASA Technical Reports Server (NTRS)

    Alencar, A.; Nepstad, D.; Ver-Diaz, M. Del. C.

    2004-01-01

    "Understory fires" that burn the floor of standing forests are one of the most important types of forest impoverishment in the Amazon, especially during the severe droughts of El Nino Southern Oscillation (ENSO) episodes. However, we are aware of no estimates of the areal extent of these fires for the Brazilian Amazon and, hence, of their contribution to Amazon carbon fluxes to the atmosphere. We calculated the area of forest understory fires for the Brazilian Amazon region during an El Nino (1998) and a non El Nino (1995) year based on forest fire scars mapped with satellite images for three locations in eastern and southern Amazon, where deforestation is concentrated. The three study sites represented a gradient of both forest types and dry season severity. The burning scar maps were used to determine how the percentage of forest that burned varied with distance from agricultural clearings. These spatial functions were then applied to similar forest/climate combinations outside of the study sites to derive an initial estimate for the Brazilian Amazon. Ninety-one percent of the forest area that burned in the study sites was within the first kilometer of a clearing for the non ENSO year and within the first four kilometers for the ENSO year. The area of forest burned by understory forest fire during the severe drought (ENSO) year (3.9 millions of hectares) was 13 times greater than the area burned during the average rainfall year (0.2 million hectares), and twice the area of annual deforestation rate. Dense forest was, proportionally, the forest area most affected by understory fires during the El Nino year, while understory fires were concentrated in transitional forests during the year of average rainfall. Our estimate of aboveground tree biomass killed by fire ranged from 0.06 Pg to 0.38 Pg during the ENSO and from 0,004 Pg to 0,024 Pg during the non ENSO.

  9. Salvage logging effect on soil properties in a fire-affected Mediterranean forest: a two years monitoring research

    NASA Astrophysics Data System (ADS)

    Mataix-Solera, Jorge; Moltó, Jorge; Arcenegui, Vicky; García-Orenes, Fuensanta; Chrenkovà, Katerina; Torres, Pilar; Jara-Navarro, Ana B.; Díaz, Gisela; Izquierdo, Ezequiel

    2015-04-01

    In the Mediterranean countries, forest fires are common and must be considered as an ecological factor, but changes in land use, especially in the last five decades have provoked a modification in their natural regime. Moreover, post-fire management can have an additional impact on the ecosystem; in some cases, even more severe than the fire. Salvage logging is a traditional management in most fire-affected areas. In some cases, the way of doing it, using heavy machinery, and the vulnerability of soils to erosion and degradation make this management potentially very agresive to soil, and therefore to the ecosystem. Very little research has been done to study how this treatment could affect soil health. In this research we show 2 years of monitoring of some soil properties in an area affected by a forest fire, where some months later this treatment was applied. 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 consisting in a complete extraction of the burned wood using heavy machinery was applied in a part of the affected forest. Plots for monitoring this effect were installed in this area and in a similar nearby area where no treatment was done, and then used as control (C) for comparison. Soil samplings were done immediately after treatment and every 6 months. Some soil properties were analysed, including soil organic matter (SOM) content, basal soil respiration (BSR), microbial biomass carbon (MBC), bulk density (BD), soil water repellency (SWR), aggregate stability (AS), field capacity, nitrogen, etc. After two years of

  10. A Five-Year CMAQ PM2.5 Model Performance for Wildfires and Prescribed Fires

    NASA Astrophysics Data System (ADS)

    Wilkins, J. L.; Pouliot, G.; Foley, K.; Rappold, A.; Pierce, T. E.

    2016-12-01

    Biomass burning has been identified as an important contributor to the degradation of air quality because of its impact on ozone and particulate matter. Two components of the biomass burning inventory, wildfires and prescribed fires are routinely estimated in the national emissions inventory. However, there is a large amount of uncertainty in the development of these emission inventory sectors. We have completed a 5 year set of CMAQ model simulations (2008-2012) in which we have simulated regional air quality with and without the wildfire and prescribed fire inventory. We will examine CMAQ model performance over regions with significant PM2.5 and Ozone contribution from prescribed fires and wildfires. We will also review plume rise to see how it affects model bias and compare CMAQ current fire emissions input to an hourly dataset from FLAMBE.

  11. Influence of wildfires on atmospheric composition and carbon uptake of forest ecosystems in Central Siberia: the establishing of a long-term post-fire monitoring system

    NASA Astrophysics Data System (ADS)

    Panov, Alexey; Chi, Xuguang; Winderlich, Jan; Prokushkin, Anatoly; Bryukhanov, Alexander; Korets, Mikhail; Ponomarev, Evgenii; Timokhina, Anastasya; Andreae, Meinrat O.; Heimann, Martin

    2014-05-01

    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

  12. Updated logistic regression equations for the calculation of post-fire debris-flow likelihood in the western United States

    USGS Publications Warehouse

    Staley, Dennis M.; Negri, Jacquelyn A.; Kean, Jason W.; Laber, Jayme L.; Tillery, Anne C.; Youberg, Ann M.

    2016-06-30

    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.

  13. Ten-year responses of oak regeneration to prescribed fire

    Treesearch

    Erik Berg; Barry Clinton; Jim Vose; Wayne Swank

    2011-01-01

    Prescribed fire has proven effective in controlling vegetative competition of oak regeneration across many sites in the southeastern US most fire investigations have been performed in the Piedmont and Coastal Plain. Land managers lake definitive knowledge on how to use prescribed fire to improve long-term oak regeneration success in the southern Appalachians. Several...

  14. Wildland fire management and air quality in the southern Sierra Nevada: using the Lion Fire as a case study with a multi-year perspective on PM(2.5) impacts and fire policy.

    PubMed

    Schweizer, Don; Cisneros, Ricardo

    2014-11-01

    Management of fire is an important and controversial policy issue. Active fire suppression has led to a backlog of fuels, limited the ecological benefits of fire, and reduced short-term smoke impacts likely delaying these emissions to future generations over a larger spatial extent. Smoke impacts can be expected to increase as fire size and intensity increase and the fuel backlog is consumed; whether through reintroduction of fire under desirable conditions or through stand replacing fire. Land Management Agencies would like to increase the use of naturally ignited fires to burn during favorable conditions as a way to reduce catastrophic fires. This study provides information about the levels of air quality impacts expected from these types of fires and discusses some of the policy controversies of managed fire that propagate inconsistencies between agencies and enter the public discourse. The Lion Fire, a primarily low intensity 8,370 ha fire that was extensively monitored for Particulate Matter less than 2.5 microns (PM2.5), is used to quantify impacts to air quality. PM2.5 monitoring sites are used to assess exposure, public health impacts, and subsequently quantify annual air quality during a year with a fire that is within the historic normal fire size and intensity for this area. Ground level PM2.5 impacts were found to be localized with 99% of the hourly Air Quality Index readings in the moderate or good category for the sites impacted by the fire. PM2.5 concentrations at sites nearest the fire were below annual federal air quality standards for PM2.5 with annual 98th percentile at the most impacted sites (Johnsondale, Kernville, and Camp Nelson) of 35.0, 34.0, and 28.0 μg m(-3) respectively. Smoke impacts to PM2.5 concentrations were not found to reach the populated Central Valley. The findings suggest that this type of fire can be implemented with minimal public health impacts thus allowing an opportunity for air and fire managers to alter policy to

  15. Fire Effects at the Tundra-Boreal Ecotone in Interior Alaska

    NASA Astrophysics Data System (ADS)

    Howard, B. K.; Mack, M. C.; Johnstone, J. F.; Walker, X. J.; Roland, C.

    2016-12-01

    Climate warming in northern latitudes has led to an intensification of disturbance by wildfire. Little is known about the effects of fire on tundra vegetation. Changes in vegetation composition could have important implications for carbon cycling , and may feedback positively or negatively to future climate change (Randerson et al., 2006). Our study utilizes extensive pre-fire ecological data collected by the National Park Service (NPS) Inventory and Monitoring (I&M) program to assess the prefire conditions important in driving successional pathways within Denali National Park and Preserve. In 2013, the East Toklat fire burned 30,000 acres of tussock tundra and mixed white and black spruce forest at a high severity, which encompassed 50 NPS plots that were originally monitored in 2003. Our sampling occurred the summer of 2016 following the same NPS protocols to assess post-fire vegetation composition. In addition, we conducted a seeding experiment using locally collected white and black spruce seed to assess natural and potential tree regeneration in unburned and post fire environments. Seed traps were established along our transects to assess seed rain. A multivariate approach will be used to assess post-fire community dynamics and future field seasons will address tree germination and survival rates. These data will then be coupled with pre and post-fire ecological data to parse out important factors driving secondary succession.

  16. 46 CFR 116.530 - Fire control plan.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Fire control plan. 116.530 Section 116.530 Shipping... and Embarkation Station Requirements § 116.530 Fire control plan. A fire control plan must be posted on the vessel in a location that is accessible and visible to all passengers. The plan must show...

  17. 46 CFR 116.530 - Fire control plan.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Fire control plan. 116.530 Section 116.530 Shipping... and Embarkation Station Requirements § 116.530 Fire control plan. A fire control plan must be posted on the vessel in a location that is accessible and visible to all passengers. The plan must show...

  18. 46 CFR 116.530 - Fire control plan.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Fire control plan. 116.530 Section 116.530 Shipping... and Embarkation Station Requirements § 116.530 Fire control plan. A fire control plan must be posted on the vessel in a location that is accessible and visible to all passengers. The plan must show...

  19. 46 CFR 116.530 - Fire control plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Fire control plan. 116.530 Section 116.530 Shipping... and Embarkation Station Requirements § 116.530 Fire control plan. A fire control plan must be posted on the vessel in a location that is accessible and visible to all passengers. The plan must show...

  20. 46 CFR 116.530 - Fire control plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Fire control plan. 116.530 Section 116.530 Shipping... and Embarkation Station Requirements § 116.530 Fire control plan. A fire control plan must be posted on the vessel in a location that is accessible and visible to all passengers. The plan must show...