46 CFR 130.470 - Fire alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... fire detector and control unit must be of a type specifically approved by the Commandant (CG-ENG). (b) No fire-alarm circuit for the engine room may contain a fire detector for any other space. (c) The number and placement of fire detectors must be approved by the cognizant OCMI. [CGD 82-004 and CGD 86-074...

46 CFR 130.470 - Fire alarms.

Code of Federal Regulations, 2011 CFR

2011-10-01

... fire detector and control unit must be of a type specifically approved by the Commandant (CG-521). (b) No fire-alarm circuit for the engine room may contain a fire detector for any other space. (c) The number and placement of fire detectors must be approved by the cognizant OCMI. [CGD 82-004 and CGD 86-074...

46 CFR 130.470 - Fire alarms.

Code of Federal Regulations, 2010 CFR

2010-10-01

... fire detector and control unit must be of a type specifically approved by the Commandant (CG-521). (b) No fire-alarm circuit for the engine room may contain a fire detector for any other space. (c) The number and placement of fire detectors must be approved by the cognizant OCMI. [CGD 82-004 and CGD 86-074...

46 CFR 130.470 - Fire alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... fire detector and control unit must be of a type specifically approved by the Commandant (CG-ENG). (b) No fire-alarm circuit for the engine room may contain a fire detector for any other space. (c) The number and placement of fire detectors must be approved by the cognizant OCMI. [CGD 82-004 and CGD 86-074...

46 CFR 130.470 - Fire alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... fire detector and control unit must be of a type specifically approved by the Commandant (CG-ENG). (b) No fire-alarm circuit for the engine room may contain a fire detector for any other space. (c) The number and placement of fire detectors must be approved by the cognizant OCMI. [CGD 82-004 and CGD 86-074...

Wildfire seasonality and land use: when do wildfires prefer to burn?

PubMed

Bajocco, Sofia; Pezzatti, Gianni Boris; Mazzoleni, Stefano; Ricotta, Carlo

2010-05-01

Because of the increasing anthropogenic fire activity, understanding the role of land-use in shaping wildfire regimes has become a major concern. In the last decade, an increasing number of studies have been carried out on the relationship between land-use and wildfire patterns, in order to identify land-use types where fire behaves selectively, showing a marked preference (or avoidance) in terms of fire incidence. By contrast, the temporal aspects of the relationship between landuse types and wildfire occurrence have received far less attention. The aim of this paper is, thus, to analyze the temporal patterns of fire occurrence in Sardinia (Italy) during the period 2000-2006 to identify land-use types where wildfires occur earlier or later than expected from a random null model. The study highlighted a close relationship between the timing of fire occurrence and land-cover that is primarily governed by two complementary processes: climatic factors that act indirectly on the timing of wildfires determining the spatial distribution of land-use types, and human population and human pressure that directly influence fire ignition. From a practical viewpoint, understanding the temporal trends of wildfires within the different land-use classes can be an effective decision-support tool for fire agencies in managing fire risk and for producing provisional models of fire behavior under changing climatic scenarios and evolving landscapes.

Fire Safety Technician

ERIC Educational Resources Information Center

Moore, Pam

2007-01-01

Fire protection is one of the most important considerations in the construction and operation of industrial plants and commercial buildings. Fire insurance rates are determined by fire probability factors, such as the type of construction, ease of transporting personnel, and the quality and quantity of fire protection equipment available. Because…

Climate change, fire management, and ecological services in the southwestern US

USGS Publications Warehouse

Hurteau, Matthew D.; Bradford, John B.; Fulé, Peter Z.; Taylor, Alan H.; Martin, Katherine L.

2014-01-01

The diverse forest types of the southwestern US are inseparable from fire. Across climate zones in California, Nevada, Arizona, and New Mexico, fire suppression has left many forest types out of sync with their historic fire regimes. As a result, high fuel loads place them at risk of severe fire, particularly as fire activity increases due to climate change. A legacy of fire exclusion coupled with a warming climate has led to increasingly large and severe wildfires in many southwest forest types. Climate change projections include an extended fire season length due to earlier snowmelt and a general drying trend due to rising temperatures. This suggests the future will be warmer and drier regardless of changes in precipitation. Hotter, drier conditions are likely to increase forest flammability, at least initially. Changes in climate alone have the potential to alter the distribution of vegetation types within the region, and climate-driven shifts in vegetation distribution are likely to be accelerated when coupled with stand-replacing fire. Regardless of the rate of change, the interaction of climate and fire and their effects on Southwest ecosystems will alter the provisioning of ecosystem services, including carbon storage and biodiversity. Interactions between climate, fire, and vegetation growth provide a source of great uncertainty in projecting future fire activity in the region, as post-fire forest recovery is strongly influenced by climate and subsequent fire frequency. Severe fire can be mitigated with fuels management including prescribed fire, thinning, and wildfire management, but new strategies are needed to ensure the effectiveness of treatments across landscapes. We review the current understanding of the relationship between fire and climate in the Southwest, both historical and projected. We then discuss the potential implications of climate change for fire management and examine the potential effects of climate change and fire on ecosystem services. We conclude with an assessment of the role of fire management in an increasingly flammable Southwest.

Bits or Shots in Combat? The Generalized Deitchman Model of Guerrilla Warfare

DTIC Science & Technology

2013-08-13

fire; absence of intelligence leads to unaimed fire, dependent on targets’ density. We propose a new Lanchester -type model that mixes aimed and unaimed...military hardware. The idea of modeling the trade-off between firepower and intelligence in a Lanchester setting was first suggested by Schreiber [4...of intelligence leads to unaimed fire, dependent on targets? density. We propose a new Lanchester -type model that mixes aimed and unaimed fire, the

Pezizalean mycorrhizas and sporocarps in ponderosa pine (Pinus ponderosa) after prescribed fires in eastern Oregon, USA.

PubMed

Fujimura, K E; Smith, J E; Horton, T R; Weber, N S; Spatafora, J W

2005-03-01

Post-fire Pezizales fruit commonly in many forest types after fire. The objectives of this study were to determine which Pezizales appeared as sporocarps after a prescribed fire in the Blue Mountains of eastern Oregon, and whether species of Pezizales formed mycorrhizas on ponderosa pine, whether or not they were detected from sporocarps. Forty-two sporocarp collections in five genera (Anthracobia, Morchella, Peziza, Scutellinia, Tricharina) of post-fire Pezizales produced ten restriction fragment length polymorphism (RFLP) types. We found no root tips colonized by species of post-fire Pezizales fruiting at our site. However, 15% (6/39) of the RFLP types obtained from mycorrhizal roots within 32 soil cores were ascomycetes. Phylogenetic analyses of the 18S nuclear ribosomal DNA gene indicated that four of the six RFLP types clustered with two genera of the Pezizales, Wilcoxina and Geopora. Subsequent analyses indicated that two of these mycobionts were probably Wilcoxina rehmii, one Geopora cooperi, and one Geopora sp. The identities of two types were not successfully determined with PCR-based methods. Results contribute knowledge about the above- and below-ground ascomycete community in a ponderosa pine forest after a low intensity fire.

Fire ecology of the forest habitat types of northern Idaho

Treesearch

Jane Kapler Smith; William C. Fischer

1997-01-01

Provides information on fire ecology in forest habitat and community types occurring in northern Idaho. Identifies fire groups based on presettlement fire regimes and patterns of succession and stand development after fire. Describes forest fuels and suggests considerations for fire management.

Remote sensing analysis of vegetation recovery following short-interval fires in Southern California shrublands.

PubMed

Meng, Ran; Dennison, Philip E; D'Antonio, Carla M; Moritz, Max A

2014-01-01

Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change. Short interval fires are widely considered to be detrimental to reestablishment of shrub species in southern California chaparral, facilitating the invasion of exotic annuals and producing "type conversion". However, supporting evidence for type conversion has largely been at local, site scales and over short post-fire time scales. Type conversion has not been shown to be persistent or widespread in chaparral, and past range improvement studies present evidence that chaparral type conversion may be difficult and a relatively rare phenomenon across the landscape. With the aid of remote sensing data covering coastal southern California and a historical wildfire dataset, the effects of short interval fires (<8 years) on chaparral recovery were evaluated by comparing areas that burned twice to adjacent areas burned only once. Twelve pairs of once- and twice-burned areas were compared using normalized burn ratio (NBR) distributions. Correlations between measures of recovery and explanatory factors (fire history, climate and elevation) were analyzed by linear regression. Reduced vegetation cover was found in some lower elevation areas that were burned twice in short interval fires, where non-sprouting species are more common. However, extensive type conversion of chaparral to grassland was not evident in this study. Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery.

Remote Sensing Analysis of Vegetation Recovery following Short-Interval Fires in Southern California Shrublands

PubMed Central

Meng, Ran; Dennison, Philip E.; D’Antonio, Carla M.; Moritz, Max A.

2014-01-01

Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change. Short interval fires are widely considered to be detrimental to reestablishment of shrub species in southern California chaparral, facilitating the invasion of exotic annuals and producing “type conversion”. However, supporting evidence for type conversion has largely been at local, site scales and over short post-fire time scales. Type conversion has not been shown to be persistent or widespread in chaparral, and past range improvement studies present evidence that chaparral type conversion may be difficult and a relatively rare phenomenon across the landscape. With the aid of remote sensing data covering coastal southern California and a historical wildfire dataset, the effects of short interval fires (<8 years) on chaparral recovery were evaluated by comparing areas that burned twice to adjacent areas burned only once. Twelve pairs of once- and twice-burned areas were compared using normalized burn ratio (NBR) distributions. Correlations between measures of recovery and explanatory factors (fire history, climate and elevation) were analyzed by linear regression. Reduced vegetation cover was found in some lower elevation areas that were burned twice in short interval fires, where non-sprouting species are more common. However, extensive type conversion of chaparral to grassland was not evident in this study. Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery. PMID:25337785

Climatic and Landscape Influences on Fire Regimes from 1984 to 2010 in the Western United States

PubMed Central

Liu, Zhihua; Wimberly, Michael C.

2015-01-01

An improved understanding of the relative influences of climatic and landscape controls on multiple fire regime components is needed to enhance our understanding of modern fire regimes and how they will respond to future environmental change. To address this need, we analyzed the spatio-temporal patterns of fire occurrence, size, and severity of large fires (> 405 ha) in the western United States from 1984–2010. We assessed the associations of these fire regime components with environmental variables, including short-term climate anomalies, vegetation type, topography, and human influences, using boosted regression tree analysis. Results showed that large fire occurrence, size, and severity each exhibited distinctive spatial and spatio-temporal patterns, which were controlled by different sets of climate and landscape factors. Antecedent climate anomalies had the strongest influences on fire occurrence, resulting in the highest spatial synchrony. In contrast, climatic variability had weaker influences on fire size and severity and vegetation types were the most important environmental determinants of these fire regime components. Topography had moderately strong effects on both fire occurrence and severity, and human influence variables were most strongly associated with fire size. These results suggest a potential for the emergence of novel fire regimes due to the responses of fire regime components to multiple drivers at different spatial and temporal scales. Next-generation approaches for projecting future fire regimes should incorporate indirect climate effects on vegetation type changes as well as other landscape effects on multiple components of fire regimes. PMID:26465959

The influence of weather and fuel type on the fuel composition of the area burned by forest fires in Ontario, 1996-2006.

PubMed

Podur, Justin J; Martell, David L

2009-07-01

Forest fires are influenced by weather, fuels, and topography, but the relative influence of these factors may vary in different forest types. Compositional analysis can be used to assess the relative importance of fuels and weather in the boreal forest. Do forest or wild land fires burn more flammable fuels preferentially or, because most large fires burn in extreme weather conditions, do fires burn fuels in the proportions they are available despite differences in flammability? In the Canadian boreal forest, aspen (Populus tremuloides) has been found to burn in less than the proportion in which it is available. We used the province of Ontario's Provincial Fuels Database and fire records provided by the Ontario Ministry of Natural Resources to compare the fuel composition of area burned by 594 large (>40 ha) fires that occurred in Ontario's boreal forest region, a study area some 430,000 km2 in size, between 1996 and 2006 with the fuel composition of the neighborhoods around the fires. We found that, over the range of fire weather conditions in which large fires burned and in a study area with 8% aspen, fires burn fuels in the proportions that they are available, results which are consistent with the dominance of weather in controlling large fires.

7 CFR 29.2269 - Fire-cured.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Fire-cured. 29.2269 Section 29.2269 Agriculture... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2269 Fire-cured. Tobacco cured under artificial atmospheric conditions by the use of open fires from which the...

Representation of spontaneous movement by dopaminergic neurons is cell-type selective and disrupted in parkinsonism

PubMed Central

Dreyer, Jakob K.; Jennings, Katie A.; Syed, Emilie C. J.; Wade-Martins, Richard; Cragg, Stephanie J.; Bolam, J. Paul; Magill, Peter J.

2016-01-01

Midbrain dopaminergic neurons are essential for appropriate voluntary movement, as epitomized by the cardinal motor impairments arising in Parkinson’s disease. Understanding the basis of such motor control requires understanding how the firing of different types of dopaminergic neuron relates to movement and how this activity is deciphered in target structures such as the striatum. By recording and labeling individual neurons in behaving mice, we show that the representation of brief spontaneous movements in the firing of identified midbrain dopaminergic neurons is cell-type selective. Most dopaminergic neurons in the substantia nigra pars compacta (SNc), but not in ventral tegmental area or substantia nigra pars lateralis, consistently represented the onset of spontaneous movements with a pause in their firing. Computational modeling revealed that the movement-related firing of these dopaminergic neurons can manifest as rapid and robust fluctuations in striatal dopamine concentration and receptor activity. The exact nature of the movement-related signaling in the striatum depended on the type of dopaminergic neuron providing inputs, the striatal region innervated, and the type of dopamine receptor expressed by striatal neurons. Importantly, in aged mice harboring a genetic burden relevant for human Parkinson’s disease, the precise movement-related firing of SNc dopaminergic neurons and the resultant striatal dopamine signaling were lost. These data show that distinct dopaminergic cell types differentially encode spontaneous movement and elucidate how dysregulation of their firing in early Parkinsonism can impair their effector circuits. PMID:27001837

11. RW Meyer Sugar Mill: 18761889. Locomotive=type, firetube, portable boiler, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. RW Meyer Sugar Mill: 1876-1889. Locomotive=type, fire-tube, portable boiler, model No. 1, Manufactured by Ames Iron Works, Oswego, New York, 1879. 120 lbs./sq. in. working pressure, 66 sq. ft. heating surface in tubes. View: the boiler provided steam for steam engine which in turn powered the centrifugals. View shows front fire box, end of boiler. Below fire-box,used for removing ashes, is a door. Circular openings at the rear of the fire-box are where fire-tubes connected with furnace. Column to right of fire-box carried pressure and water level gauges. Fluted chimney-type structure is steam-port, safety valve, and whistle. Weights originally sat on the arm extending from the top of the port and controlled the boiler pressure. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Predicting the effect of fire on large-scale vegetation patterns in North America.

Treesearch

Donald McKenzie; David L. Peterson; Ernesto. Alvarado

1996-01-01

Changes in fire regimes are expected across North America in response to anticipated global climatic changes. Potential changes in large-scale vegetation patterns are predicted as a result of altered fire frequencies. A new vegetation classification was developed by condensing Kuchler potential natural vegetation types into aggregated types that are relatively...

30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water systems... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic fire sensors; actuation of fire...

30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water systems...

30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water systems...

30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water systems...

30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water systems...

Landscape-scale effects of fire severity on mixed-conifer and red fir forest structure in Yosemite National Park

USGS Publications Warehouse

Kane, Van R.; Lutz, James A.; Roberts, Susan L.; Smith, Douglas F.; McGaughey, Robert J.; Povak, Nicholas A.; Brooks, Matthew L.

2013-01-01

While fire shapes the structure of forests and acts as a keystone process, the details of how fire modifies forest structure have been difficult to evaluate because of the complexity of interactions between fires and forests. We studied this relationship across 69.2 km2 of Yosemite National Park, USA, that was subject to 32 fires ⩾40 ha between 1984 and 2010. Forests types included ponderosa pine (Pinus ponderosa), white fir-sugar pine (Abies concolor/Pinus lambertiana), and red fir (Abies magnifica). We estimated and stratified burned area by fire severity using the Landsat-derived Relativized differenced Normalized Burn Ratio (RdNBR). Airborne LiDAR data, acquired in July 2010, measured the vertical and horizontal structure of canopy material and landscape patterning of canopy patches and gaps. Increasing fire severity changed structure at the scale of fire severity patches, the arrangement of canopy patches and gaps within fire severity patches, and vertically within tree clumps. Each forest type showed an individual trajectory of structural change with increasing fire severity. As a result, the relationship between estimates of fire severity such as RdNBR and actual changes appears to vary among forest types. We found three arrangements of canopy patches and gaps associated with different fire severities: canopy-gap arrangements in which gaps were enclosed in otherwise continuous canopy (typically unburned and low fire severities); patch-gap arrangements in which tree clumps and gaps alternated and neither dominated (typically moderate fire severity); and open-patch arrangements in which trees were scattered across open areas (typically high fire severity). Compared to stands outside fire perimeters, increasing fire severity generally resulted first in loss of canopy cover in lower height strata and increased number and size of gaps, then in loss of canopy cover in higher height strata, and eventually the transition to open areas with few or no trees. However, the estimated fire severities at which these transitions occurred differed for each forest type. Our work suggests that low severity fire in red fir forests and moderate severity fire in ponderosa pine and white fir-sugar pine forests would restore vertical and horizontal canopy structures believed to have been common prior to the start of widespread fire suppression in the early 1900s. The fusion of LiDAR and Landsat data identified post-fire structural conditions that would not be identified by Landsat alone, suggesting a broad applicability of combining Landsat and LiDAR data for landscape-scale structural analysis for fire management.

A population model of chaparral vegetation response to frequent wildfires.

PubMed

Lucas, Timothy A; Johns, Garrett; Jiang, Wancen; Yang, Lucie

2013-12-01

The recent increase in wildfire frequency in the Santa Monica Mountains (SMM) may substantially impact plant community structure. Species of Chaparral shrubs represent the dominant vegetation type in the SMM. These species can be divided into three life history types according to their response to wildfires. Nonsprouting species are completely killed by fire and reproduce by seeds that germinate in response to a fire cue, obligate sprouting species survive by resprouting from dormant buds in a root crown because their seeds are destroyed by fire, and facultative sprouting species recover after fire both by seeds and resprouts. Based on these assumptions, we developed a set of nonlinear difference equations to model each life history type. These models can be used to predict species survivorship under varying fire return intervals. For example, frequent fires can lead to localized extinction of nonsprouting species such as Ceanothus megacarpus while several facultative sprouting species such as Ceanothus spinosus and Malosma (Rhus) laurina will persist as documented by a longitudinal study in a biological preserve in the SMM. We estimated appropriate parameter values for several chaparral species using 25 years of data and explored parameter relationships that lead to equilibrium populations. We conclude by looking at the survival strategies of these three species of chaparral shrubs under varying fire return intervals and predict changes in plant community structure under fire intervals of short return. In particular, our model predicts that an average fire return interval of greater than 12 years is required for 50 % of the initial Ceanothus megacarpus population and 25 % of the initial Ceanothus spinosus population to survive. In contrast, we predict that the Malosma laurina population will have 90 % survivorship for an average fire return interval of at least 6 years.

Space-time clustering analysis of wildfires: The influence of dataset characteristics, fire prevention policy decisions, weather and climate.

PubMed

Parente, Joana; Pereira, Mário G; Tonini, Marj

2016-07-15

The present study focuses on the dependence of the space-time permutation scan statistics (STPSS) (1) on the input database's characteristics and (2) on the use of this methodology to assess changes on the fire regime due to different type of climate and fire management activities. Based on the very strong relationship between weather and the fire incidence in Portugal, the detected clusters will be interpreted in terms of the atmospheric conditions. Apart from being the country most affected by the fires in the European context, Portugal meets all the conditions required to carry out this study, namely: (i) two long and comprehensive official datasets, i.e. the Portuguese Rural Fire Database (PRFD) and the National Mapping Burnt Areas (NMBA), respectively based on ground and satellite measurements; (ii) the two types of climate (Csb in the north and Csa in the south) that characterizes the Mediterranean basin regions most affected by the fires also divide the mainland Portuguese area; and, (iii) the national plan for the defence of forest against fires was approved a decade ago and it is now reasonable to assess its impacts. Results confirmed (1) the influence of the dataset's characteristics on the detected clusters, (2) the existence of two different fire regimes in the country promoted by the different types of climate, (3) the positive impacts of the fire prevention policy decisions and (4) the ability of the STPSS to correctly identify clusters, regarding their number, location, and space-time size in spite of eventual space and/or time splits of the datasets. Finally, the role of the weather on days when clustered fires were active was confirmed for the classes of small, medium and large fires. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of potential fire regimes: applying landscape ecology to fire management in Mexico

NASA Astrophysics Data System (ADS)

Jardel, E.; Alvarado, E.; Perez-Salicrup, D.; Morfín-Rios, J.

2013-05-01

Knowledge and understanding of fire regimes is fundamental to design sound fire management practices. The high ecosystem diversity of Mexico offers a great challenge to characterize the fire regime variation at the landscape level. A conceptual model was developed considering the main factors controlling fire regimes: climate and vegetation cover. We classified landscape units combining bioclimatic zones from the Holdridge life-zone system and actual vegetation cover. Since bioclimatic conditions control primary productivity and biomass accumulation (potential fuel), each landscape unit was considered as a fuel bed with a particular fire intensity and behavior potential. Climate is also a determinant factor of post-fire recovery rates of fuel beds, and climate seasonality (length of the dry and wet seasons) influences fire probability (available fuel and ignition efficiency). These two factors influence potential fire frequency. Potential fire severity can be inferred from fire frequency, fire intensity and behavior, and vegetation composition and structure. Based in the conceptual model, an exhaustive literature review and expert opinion, we developed rules to assign a potential fire regime (PFR) defined by frequency, intensity and severity (i.e. fire regime) to each bioclimatic-vegetation landscape unit. Three groups and eight types of potential fire regimes were identified. In Group A are fire-prone ecosystems with frequent low severity surface fires in grasslands (PFR type I) or forests with long dry season (II) and infrequent high-severity fires in chaparral (III), wet temperate forests (IV, fire restricted by humidity), and dry temperate forests (V, fire restricted by fuel recovery rate). Group B includes fire-reluctant ecosystems with very infrequent or occasional mixed severity surface fires limited by moisture in tropical rain forests (VI) or fuel availability in seasonally dry tropical forests (VII). Group C and PFR VIII include fire-free environments that correspond to deserts. Application of PFR model to fire management is discussed.

46 CFR 161.002-12 - Manual fire alarm systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the control unit and terminating at manual fire alarm boxes. Power failure alarm devices may be... specifically approved. (b) Types. Manual fire alarm systems shall be one of the following types, or a... using manually operated fire alarm boxes. (3) Other types as may be developed. (c) Power supply. The...

46 CFR 161.002-12 - Manual fire alarm systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the control unit and terminating at manual fire alarm boxes. Power failure alarm devices may be... specifically approved. (b) Types. Manual fire alarm systems shall be one of the following types, or a... using manually operated fire alarm boxes. (3) Other types as may be developed. (c) Power supply. The...

46 CFR 161.002-12 - Manual fire alarm systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the control unit and terminating at manual fire alarm boxes. Power failure alarm devices may be... specifically approved. (b) Types. Manual fire alarm systems shall be one of the following types, or a... using manually operated fire alarm boxes. (3) Other types as may be developed. (c) Power supply. The...

Fire-mediated disruptive selection can explain the reseeder-resprouter dichotomy in Mediterranean-type vegetation.

PubMed

Altwegg, Res; De Klerk, Helen M; Midgley, Guy F

2015-02-01

Crown fire is a key selective pressure in Mediterranean-type plant communities. Adaptive responses to fire regimes involve trade-offs between investment for persistence (fire survival and resprouting) and reproduction (fire mortality, fast growth to reproductive maturity, and reseeding) as investments that enhance adult survival lower growth and reproductive rates. Southern hemisphere Mediterranean-type ecosystems are dominated by species with either endogenous regeneration from adult resprouting or fire-triggered seedling recruitment. Specifically, on nutrient-poor soils, these are either resprouting or reseeding life histories, with few intermediate forms, despite the fact that the transition between strategies is evolutionarily labile. How did this strong dichotomy evolve? We address this question by developing a stochastic demographic model to assess determinants of relative fitness of reseeders, resprouters and hypothetical intermediate forms. The model was parameterised using published demographic data from South African protea species and run over various relevant fire regime parameters facets. At intermediate fire return intervals, trade-offs between investment in growth versus fire resilience can cause fitness to peak at either of the extremes of the reseeder-resprouter continuum, especially when assuming realistic non-linear shapes for these trade-offs. Under these circumstances, the fitness landscape exhibits a saddle which could lead to disruptive selection. The fitness gradient between the peaks was shallow, which may explain why this life-history trait is phylogenetically labile. Resprouters had maximum fitness at shorter fire-return intervals than reseeders. The model suggests that a strong dichotomy in fire survival strategy depends on a non-linear trade-off between growth and fire persistence traits.

Fire ecology of the forest habitat types of eastern Idaho and western Wyoming

Treesearch

Anne F. Bradley; William C. Fischer; Nonan V. Noste

1992-01-01

Provides information on fire as an ecological factor in the forest habitat types occurring in eastern Idaho and western Wyoming. Identifies Fire Groups based on fire's role in forest succession. Describes forest fuels and suggests considerations for fire management.

A basic approach to fire injury of tree stems

Treesearch

R. E. Martin

1963-01-01

Fire has come to be widely used as a tool in wildland management, particularly in the South. Its usefulness in fire hazard reduction, removal of undesirable trees, and changing of cover types has been demonstrated. We are continually trying to improve fire use, however, by learning more of the specific effects of fire on different species of plants.

46 CFR 161.002-12 - Manual fire alarm systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... (a) General. A manual fire alarm system shall consist of a power supply, a control unit on which are... using manually operated fire alarm boxes. (3) Other types as may be developed. (c) Power supply. The power supply shall be as specified for automatic fire detecting system by § 161.002-9. (d) Manual fire...

46 CFR 161.002-12 - Manual fire alarm systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... (a) General. A manual fire alarm system shall consist of a power supply, a control unit on which are... using manually operated fire alarm boxes. (3) Other types as may be developed. (c) Power supply. The power supply shall be as specified for automatic fire detecting system by § 161.002-9. (d) Manual fire...

Survival analysis and classification methods for forest fire size

PubMed Central

2018-01-01

Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene) and the size at “being held” (a state when no further increase in size is expected). We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at “being held” exceeds the size at initial assessment). Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances. PMID:29320497

Survival analysis and classification methods for forest fire size.

PubMed

Tremblay, Pier-Olivier; Duchesne, Thierry; Cumming, Steven G

2018-01-01

Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene) and the size at "being held" (a state when no further increase in size is expected). We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at "being held" exceeds the size at initial assessment). Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances.

Fuel age and fire spread: Natural conditions versus opportunities for fire suppression

USGS Publications Warehouse

Halsey, Richard W.; Keeley, Jon E.; Wilson, Kit

2009-01-01

Wildfires are driven and restrained by an interplay of variables that can lead to many potential outcomes. As every wildland firefighter learns in basic training, the ability of a fire to spread is determined by three basic variables: fuel type and condition, weather, and topography. Fire suppression obviously plays a significant role in determining fire spread as well, so firefighter activity becomes an additional variable.

Interactions among livestock grazing, vegetation type, and fire behavior in the Murphy Wildland Fire Complex in Idaho and Nevada, July 2007

USGS Publications Warehouse

Launchbaugh, Karen; Brammer, Bob; Brooks, Matthew L.; Bunting, Stephen C.; Clark, Patrick; Davison, Jay; Fleming, Mark; Kay, Ron; Pellant, Mike; Pyke, David A.

2008-01-01

A series of wildland fires were ignited by lightning in sagebrush and grassland communities near the Idaho-Nevada border southwest of Twin Falls, Idaho in July 2007. The fires burned for over two weeks and encompassed more than 650,000 acres. A team of scientists, habitat specialists, and land managers was called together by Tom Dyer, Idaho BLM State Director, to examine initial information from the Murphy Wildland Fire Complex in relation to plant communities and patterns of livestock grazing. Three approaches were used to examine this topic: (1) identify potential for livestock grazing to modify fuel loads and affect fire behavior using fire models applied to various vegetation types, fuel loads, and fire conditions; (2) compare levels of fuel consumed within and among major vegetation types; and (3) examine several observed lines of difference and discontinuity in fuel consumed to determine what factors created these contrasts. The team found that much of the Murphy Wildland Fire Complex burned under extreme fuel and weather conditions that likely overshadowed livestock grazing as a factor influencing fire extent and fuel consumption in many areas where these fires burned. Differences and abrupt contrast lines in the level of fuels consumed were affected mostly by the plant communities that existed on a site before fire. A few abrupt contrasts in burn severity coincided with apparent differences in grazing patterns of livestock, observed as fence-line contrasts. Fire modeling revealed that grazing in grassland vegetation can reduce surface rate of spread and fire-line intensity to a greater extent than in shrubland types. Under extreme fire conditions (low fuel moisture, high temperatures, and gusty winds), grazing applied at moderate utilization levels has limited or negligible effects on fire behavior. However, when weather and fuel-moisture conditions are less extreme, grazing may reduce the rate of spread and intensity of fires allowing for patchy burns with low levels of fuel consumption. The team suggested that targeted grazing to accomplish fuel objectives holds promise but requires detailed planning that includes clearly defined goals for fuel modification and appropriate monitoring to assess effectiveness. It was recommended that a pilot plan be devised to strategically place grazed blocks across a landscape to create fuel-reduction bands capable of influencing fire behavior. Also suggested was the development of a general technical report that highlights information and examples of how livestock grazing influences fire extent, severity, and intensity. Finally, the team encouraged continued research and monitoring of the effects of the Murphy Wildland Fire Complex. Much more can be learned from the effects of this extensive fire complex that may offer insight for future management decisions.

The ecology of mixed severity fire regimes in Washington, Oregon, and Northern California

Treesearch

David Perry; Paul Hessburg; Carl Skinner; Thomas Spies; Scott Stephens; Alan Henry Taylor; Jerry Franklin; Brenda McComb; Greg Riegel

2011-01-01

Forests characterized by mixed-severity fires occupy a broad moisture gradient between lower elevation forests typified by low-severity fires and higher elevation forests in which high-severity, stand replacing fires are the norm. Mixed-severity forest types are poorly documented and little understood but likely occupy significant areas in the western United States. By...

30 CFR 77.1108-1 - Type and capacity of firefighting equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... UNDERGROUND COAL MINES Fire Protection § 77.1108-1 Type and capacity of firefighting equipment. Firefighting... capacity for each 1,000 tons of coal processed (average) per shift. (b) Fire extinguishers. Fire extinguishers shall be: (1) Of the appropriate type for the particular fire hazard involved; (2) Adequate in...

30 CFR 77.1108-1 - Type and capacity of firefighting equipment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... UNDERGROUND COAL MINES Fire Protection § 77.1108-1 Type and capacity of firefighting equipment. Firefighting... capacity for each 1,000 tons of coal processed (average) per shift. (b) Fire extinguishers. Fire extinguishers shall be: (1) Of the appropriate type for the particular fire hazard involved; (2) Adequate in...

Prolonged post-inhibitory rebound firing in the cerebellar nuclei mediated by group I mGluR potentiation of L-type Ca currents

PubMed Central

Zheng, Nan; Raman, Indira M.

2011-01-01

Neurons in the cerebellar nuclei fire at accelerated rates for prolonged periods after trains of synaptic inhibition that interrupt spontaneous firing. Both in vitro and in vivo, however, this prolonged rebound firing is favored by strong stimulation of afferents, suggesting that neurotransmitters other than GABA may contribute to the increased firing rates. Here, we tested whether metabotropic glutamate receptors modulate excitability of nuclear cells in cerebellar slices from mouse. In current clamp, the prolonged rebound firing rate after high-frequency synaptic stimulation was reduced by a variety of group I mGluR antagonists, including CPCCOEt (7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester), JNJ16259685 ((3,4-dihydro-2H-pyrano[2,3-b]quinolin-7-yl)-(cis-4-methoxycyclohexyl)-methanone)+MPEP, or 3-MATIDA (α-amino-5-carboxy-3-methyl-2-thiopheneacetic acid) +MPEP, as long as both mGluR1 and mGluR5 were blocked. This mGluR-dependent acceleration of firing was reduced but still evident when IPSPs were prevented by GABAA receptor antagonists. In voltage clamp, voltage ramps revealed a non-inactivating, low-voltage-activated, nimodipine-sensitive current that was enhanced by the selective group I mGluR agonist s-DHPG ((S)-3,5-dihydroxyphenylglycine). This putative L-type current also increased when mGluRs were activated by trains of evoked synaptic currents instead of direct application of agonist. In current clamp, blocking L-type Ca channels with the specific blocker nifedipine greatly reduced prolonged post-stimulus firing and occluded the effect of adding group I mGluR antagonists. Thus, potentiation of a low-voltage-activated L-type current by synaptically released glutamate accounted nearly fully for the mGluR-dependent acceleration of firing. Together, these data suggest that prolonged rebound firing in the cerebellar nuclei in vivo is most likely to occur when GABAA and mGluRs are simultaneously activated by concurrent excitation and inhibition. PMID:21753005

Foreword

Treesearch

Robert E. Keane

2011-01-01

In the mid 1980s I was asked to create a fire regime map of the Selway-Bitterroot Wilderness Area for the Bitterroot National Forest fire management staff. The well known fire historian Steve Barrett had already completed most of the work by synthesizing all available fire history results by forest habitat type, so I figured it would be easy to create a map of habitat...

Detecting the Onset of Fire in an Aircraft by Employing Correlation Spectroscopy

NASA Technical Reports Server (NTRS)

Goswami, Kisholoy; Saxena, Indu; Egalon, Claudio; Mendoza, Edgar; Lieberman, Robert; Piltch, Nancy D.

1999-01-01

The cause of aircraft fire and locations of the fires are numerous. Worldwide, numerous in-flight fires have been passenger initiated, the prime location being the lavatory areas. Most in-flight fires in commercial carriers are of electrical origin and cigarettes. A cargo bay fire can be caused by a variety of reasons. The sheer number of different types of cargo makes it difficult to identify the origin, especially when the fire reaches the catastrophic level. The damage can be minimized, and fire can be suppressed effectively if a warning system for the onset of fire is available for onboard monitoring.

Landscape scale vegetation-type conversion and fire hazard in the San Francisco bay area open spaces

USGS Publications Warehouse

Russell, W.H.; McBride, J.R.

2003-01-01

Successional pressures resulting from fire suppression and reduced grazing have resulted in vegetation-type conversion in the open spaces surrounding the urbanized areas of the San Francisco bay area. Coverage of various vegetation types were sampled on seven sites using a chronosequence of remote images in order to measure change over time. Results suggest a significant conversion of grassland to shrubland dominated by Baccharis pilularison five of the seven sites sampled. An increase in Pseudotsuga menziesii coverage was also measured on the sites where it was present. Increases fuel and fire hazard were determined through field sampling and use of the FARSITE fire area simulator. A significant increase in biomass resulting from succession of grass-dominated to shrub-dominated communities was evident. In addition, results from the FARSITE simulations indicated significantly higher fire-line intensity, and flame length associated with shrublands over all other vegetation types sampled. These results indicate that the replacement of grass dominated with shrub-dominated landscapes has increased the probability of high intensity fires. ?? 2003 Elsevier Science B.V. All rights reserved.

The forest fire season at different elevations in Idaho

Treesearch

J. A. Larsen

1925-01-01

In any fire-ridden forest region, such as north Idaho, there is great need for a tangible basis by which to judge the length and the intensity of the fire season in different forest types and at different elevations. The major and natural forest types, such as the western yellow pine forests, the western white-pine forests, and the subalpine forests occur in...

Grassland Fire and Cattle Grazing Regulate Reptile and Amphibian Assembly Among Patches

NASA Astrophysics Data System (ADS)

Larson, Danelle M.

2014-12-01

Fire and grazing are common management schemes of grasslands globally and are potential drivers of reptilian and amphibian (herpetofauna) metacommunity dynamics. Few studies have assessed the impacts of fire and cattle grazing on herpetofauna assemblages in grasslands. A patch-burn grazing study at Osage Prairie, MO, USA in 2011-2012 created landscape patches with treatments of grazing, fire, and such legacies. Response variables were measured before and after the application of treatments, and I used robust-design occupancy modeling to estimate patch occupancy and detection rate within patches, and recolonization and extinction (i.e., dispersal) across patches. I conducted redundancy analysis and a permuted multivariate analysis of variance to determine if patch type and the associated environmental factors explained herpetofauna assemblage. Estimates for reptiles indicate that occupancy was seasonally constant in Control patches ( ψ ~ 0.5), but declined to ψ ~ 0.15 in patches following the applications of fire and grazing. Local extinctions for reptiles were higher in patches with fire or light grazing ( ɛ ~ 0.7) compared to the controls. For the riparian herpetofaunal community, patch type and grass height were important predictors of abundance; further, the turtles, lizards, snakes, and adult amphibians used different patch types. The aquatic amphibian community was predicted by watershed and in-stream characteristics, irrespective of fire or grazing. The varying responses from taxonomic groups demonstrate habitat partitioning across multiple patch types undergoing fire, cattle grazing, and legacy effects. Prairies will need an array of patch types to accommodate multiple herpetofauna species.

7 CFR 29.2519 - Fire-cured.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Fire-cured. 29.2519 Section 29.2519 Agriculture... INSPECTION Standards Official Standard Grades for Kentucky and Tennessee Fire-Cured and Foreign-Grown Fire-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2519 Fire-cured. Tobacco cured under...

14 CFR 121.417 - Crewmember emergency training.

Code of Federal Regulations, 2014 CFR

2014-01-01

... fire extinguishers, with emphasis on type of extinguisher to be used on different classes of fires; and... handling of emergency situations including— (i) Rapid decompression; (ii) Fire in flight or on the surface... crewmember combats an actual or simulated fire using at least one type of installed hand fire extinguisher or...

14 CFR 121.417 - Crewmember emergency training.

Code of Federal Regulations, 2013 CFR

2013-01-01

... fire extinguishers, with emphasis on type of extinguisher to be used on different classes of fires; and... handling of emergency situations including— (i) Rapid decompression; (ii) Fire in flight or on the surface... crewmember combats an actual or simulated fire using at least one type of installed hand fire extinguisher or...

14 CFR 121.417 - Crewmember emergency training.

Code of Federal Regulations, 2012 CFR

2012-01-01

... fire extinguishers, with emphasis on type of extinguisher to be used on different classes of fires; and... handling of emergency situations including— (i) Rapid decompression; (ii) Fire in flight or on the surface... crewmember combats an actual or simulated fire using at least one type of installed hand fire extinguisher or...

Synoptic weather types associated with critical fire weather

Treesearch

Mark J. Schroeder; Monte Glovinsky; Virgil F. Hendricks; Frank C. Hood; Melvin K. Hull; Henry L. Jacobson; Robert Kirkpatrick; Daniel W. Krueger; Lester P. Mallory; Albert G. Oeztel; Robert H. Reese; Leo A. Sergius; Charles E. Syverson

1964-01-01

Recognizing that weather is an important factor in the spread of both urban and wildland fires, a study was made of the synoptic weather patterns and types which produce strong winds, low relative humidities, high temperatures, and lack of rainfall--the conditions conducive to rapid fire spread. Such historic fires as the San Francisco fire of 1906, the Berkeley fire...

Toxicity of PHOS-CHEK LC-95A and 259F fire retardants to ocean- and stream-type Chinook salmon and their potential to recover before seawater entry.

PubMed

Dietrich, Joseph P; Van Gaest, Ahna L; Strickland, Stacy A; Hutchinson, Greg P; Krupkin, Alex B; Arkoosh, Mary R

2014-08-15

Long-term fire retardants are used to prevent the spread of wildland fire, but have inadvertently entered aquatic habitats and resulted in fish kills. We examined the toxicity of two fire retardant products; PHOS-CHEK 259F and LC-95A, on Chinook salmon with two different life histories, ocean-type and stream-type, at different stages of their development. Ocean-type Chinook outmigrate to the ocean as subyearlings; while, stream-type salmon overwinter in freshwater and outmigrate as yearlings. Ocean-type and stream-type salmon were exposed to the fire retardants prior to their parr to smolt transition (presmolts) as subyearlings (stream-type and ocean-type) and yearlings (stream-type only), as well as during their transition (smolts). The salmon were exposed to eight concentrations of each retardant and a control for 96h to determine acute toxicity. Lethal concentration curves were modeled by logistic regression for each life history and life stage exposed to the two fire retardants. Among all life histories and life stages tested, PHOS-CHEK 259F was most toxic to stream-type salmon at smolt stage and PHOS-CHEK LC-95A was most toxic to ocean-type salmon at smolt stage. To determine the delayed effects of product exposures on fish health as well as for the potential of recovery, 24-hour seawater challenges were performed immediately after fire retardant exposure, as well as after a recovery period. Previous PHOS-CHEK exposure reduced survival during seawater challenge among salmon from both life histories undergoing the parr-smolt transition and was more pronounced after PHOS-CHEK LC-95A exposure. However, this delayed effect was not observed 34 or more days after either PHOS-CHEK exposure. We conclude that accidental PHOS-CHEK LC-95A or 259F drops during salmon outmigration would have adverse impacts that extend beyond the acute mortality that occurs within the immediate drop and dilution areas. Published by Elsevier B.V.

7 CFR 30.12 - Fire-cure.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Fire-cure. 30.12 Section 30.12 Agriculture Regulations... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.12 Fire-cure. To cure tobacco under artificial atmospheric conditions by the use of open fires, the smoke and...

An Educational Program Dealing with Fire Safety. Curriculum and Resource Guide.

ERIC Educational Resources Information Center

Rhode Island State Dept. of Education, Providence.

A series of activities for fire safety education in grades K-12 is presented. The document is organized into three parts: grades K-3; 4-6; and 7-12. Each activity is preceded by general and specific concepts to be stressed. Concepts for grades K-3 stress usefulness and types of fire, fire drills, the fire fighting profession, and the…

High-severity fire: Evaluating its key drivers and mapping its probability across western US forests

Treesearch

Sean A. Parks; Lisa M. Holsinger; Matthew H. Panunto; W. Matt Jolly; Solomon Z. Dobrowski; Gregory K. Dillon

2018-01-01

Wildland fire is a critical process in forests of the western United States (US). Variation in fire behavior, which is heavily influenced by fuel loading, terrain, weather, and vegetation type, leads to heterogeneity in fire severity across landscapes. The relative influence of these factors in driving fire severity, however, is poorly understood. Here, we explore the...

Field Artillery Cannon Weapons Systems and Ammunition Handbook.

DTIC Science & Technology

1981-12-01

velocity 472 meters per second Maximum range 11,000 meters Type breechblock Horizontal sliding wedge Type firing mechanism Continuous pull , M13 Type...interrupted screw Type of firing mechanism Continuous pull , M35 Type of recoil mechanism Hydropneumatic Minimum recoil 24 inches Maximum recoil 36...breechblock Threaded, interrupted screw Type of firing mechanism Continuous pull , M35 Type of recoil mechanism Hydropneurnatic Minimum recoil 50 inches +_2

The use of geographic information for fire management planning in Yosemite National Park

USGS Publications Warehouse

Van Wagtendonk, Jan W.; van Wagtendonk, Kent A.; Meyer, Joseph B.; Paintner, Kara J.

2002-01-01

Fire has played a critical role in the ecosystems of Yosemite National park for millennia. Before the advent of Euro-Americans, lightning fires and fires set by Native Americans burned freely across the landscape. These fires burned periodically, with the interval between fires dependent on the availability of ignition sources, adequate fuels, and weather conducive to burning. As a result, different vegetation types burned at different intervals.

Using ecological forecasting of future vegetation transition and fire frequency change in the Sierra Nevada to assess fire management strategies

NASA Astrophysics Data System (ADS)

Thorne, J. H.; Schwartz, M. W.; Holguin, A. J.; Moritz, M.; Batllori, E.; Folger, K.; Nydick, K.

2013-12-01

Ecological systems may respond in complex manners as climate change progresses. Among the responses, site-level climate conditions may cause a shift in vegetation due to the physiological tolerances of plant species, and the fire return interval may change. Natural resource managers challenged with maintaining ecosystem health need a way to forecast how these processes may affect every location, in order to determine appropriate management actions and prioritize locations for interventions. We integrated climate change-driven vegetation type transitions with projected change in fire frequency for 45,203 km2 of the southern Sierra Nevada, California, containing over 10 land management agencies as well as private lands. This Magnitude of Change (MOC) approach involves classing vegetation types in current time according to their climate envelopes, and identifying which sites will in the future have climates beyond what that vegetation currently occurs in. Independently, fire models are used to determine the change in fire frequency for each site. We examined 82 vegetation types with >50 grid cell occurrences. We found iconic resources such as the giant sequoia, lower slope oak woodlands, and high elevation conifer forests are projected as highly vulnerable by models that project a warmer drier future, but not as much by models that project a warmer future that is not drier than current conditions. Further, there were strongly divergent vulnerabilities of these forest types across land ownership (National Parks versus US Forest Service lands), and by GCM. For example, of 50 giant sequoia (Sequoiadendron giganteum) groves and complexes, all but 3 (on Sierra National Forest) were in the 2 highest levels of risk of climate and fire under the GFDL A2 projection, while 15 groves with low-to-moderate risk were found on both the National Parks and National Forests 18 in the 2 under PCM A2. Landscape projections of potential MOC suggest that the region is likely to experience strong upslope shifting of open grassland, chaparral and hardwood types, which may be initiated by increased fire frequencies, particularly where fires have not recently burned within normal fire recurrence interval departures (FRID). An evaluation of four fire management strategies (business as usual; resist change; foster orderly change; protect vital resources) across four combinations of future climate and fire frequency found that no single management strategy was uniformly successful in protecting critical resources across the range of future conditions examined. This limitation is somewhat driven by current management constraints on the amount of management available to resource managers, which suggests management will need to use a triage approach to application of proactive fire management strategies, wherein MOC landscape projections can be used in decision support.

Extreme wildfire events are linked to global-change-type droughts in the northern Mediterranean

NASA Astrophysics Data System (ADS)

Ruffault, Julien; Curt, Thomas; Martin-StPaul, Nicolas K.; Moron, Vincent; Trigo, Ricardo M.

2018-03-01

Increasing drought conditions under global warming are expected to alter the frequency and distribution of large and high-intensity wildfires. However, our understanding of the impact of increasing drought on extreme wildfires events remains incomplete. Here, we analyzed the weather conditions associated with the extreme wildfires events that occurred in Mediterranean France during the exceptionally dry summers of 2003 and 2016. We identified that these fires were related to two distinct shifts in the fire weather space towards fire weather conditions that had not been explored before and resulting from specific interactions between different types of drought and different fire weather types. In 2016, a long-lasting press drought intensified wind-driven fires. In 2003, a hot drought combining a heat wave with a press drought intensified heat-induced fires. Our findings highlight that increasing drought conditions projected by climate change scenarios might affect the dryness of fuel compartments and lead to a higher frequency of extremes wildfires events.

Erwinia amylovora pyrC mutant causes fire blight despite pyrimidine auxotrophy.

PubMed

Ramos, L S; Sinn, J P; Lehman, B L; Pfeufer, E E; Peter, K A; McNellis, T W

2015-06-01

Erwinia amylovora bacteria cause fire blight disease, which affects apple and pear production worldwide. The Erw. amylovora pyrC gene encodes a predicted dihydroorotase enzyme involved in pyrimidine biosynthesis. Here, we discovered that the Erw. amylovora pyrC244::Tn5 mutant was a uracil auxotroph. Unexpectedly, the Erw. amylovora pyrC244::Tn5 mutant grew as well as the wild-type in detached immature apple and pear fruits. Fire blight symptoms caused by the pyrC244::Tn5 mutant in immature apple and pear fruits were attenuated compared to those caused by the wild-type. The pyrC244::Tn5 mutant also caused severe fire blight symptoms in apple tree shoots. A plasmid-borne copy of the wild-type pyrC gene restored prototrophy and symptom induction in apple and pear fruit to the pyrC244::Tn5 mutant. These results suggest that Erw. amylovora can obtain sufficient pyrimidine from the host to support bacterial growth and fire blight disease development, although de novo pyrimidine synthesis by Erw. amylovora is required for full symptom development in fruits. Significance and impact of the study: This study provides information about the fire blight host-pathogen interaction. Although the Erwinia amylovora pyrC mutant was strictly auxotrophic for pyrimidine, it grew as well as the wild-type in immature pear and apple fruits and caused severe fire blight disease in apple trees. This suggests that Erw. amylovora can obtain sufficient pyrimidines from host tissue to support growth and fire blight disease development. This situation contrasts with findings in some human bacterial pathogens, which require de novo pyrimidine synthesis for growth in host blood, for example. © 2015 The Society for Applied Microbiology.

Identification of two distinct fire regimes in Southern California: implications for economic impact and future change

NASA Astrophysics Data System (ADS)

Jin, Yufang; Goulden, Michael L.; Faivre, Nicolas; Veraverbeke, Sander; Sun, Fengpeng; Hall, Alex; Hand, Michael S.; Hook, Simon; Randerson, James T.

2015-09-01

The area burned by Southern California wildfires has increased in recent decades, with implications for human health, infrastructure, and ecosystem management. Meteorology and fuel structure are universally recognized controllers of wildfire, but their relative importance, and hence the efficacy of abatement and suppression efforts, remains controversial. Southern California’s wildfires can be partitioned by meteorology: fires typically occur either during Santa Ana winds (SA fires) in October through April, or warm and dry periods in June through September (non-SA fires). Previous work has not quantitatively distinguished between these fire regimes when assessing economic impacts or climate change influence. Here we separate five decades of fire perimeters into those coinciding with and without SA winds. The two fire types contributed almost equally to burned area, yet SA fires were responsible for 80% of cumulative 1990-2009 economic losses (3.1 Billion). The damage disparity was driven by fire characteristics: SA fires spread three times faster, occurred closer to urban areas, and burned into areas with greater housing values. Non-SA fires were comparatively more sensitive to age-dependent fuels, often occurred in higher elevation forests, lasted for extended periods, and accounted for 70% of total suppression costs. An improved distinction of fire type has implications for future projections and management. The area burned in non-SA fires is projected to increase 77% (±43%) by the mid-21st century with warmer and drier summers, and the SA area burned is projected to increase 64% (±76%), underscoring the need to evaluate the allocation and effectiveness of suppression investments.

Spatial-Temporal Dynamics of Urban Fire Incidents: a Case Study of Nanjing, China

NASA Astrophysics Data System (ADS)

Yao, J.; Zhang, X.

2016-06-01

Fire and rescue service is one of the fundamental public services provided by government in order to protect people, properties and environment from fires and other disasters, and thus promote a safer living environment. Well understanding spatial-temporal dynamics of fire incidents can offer insights for potential determinants of various fire events and enable better fire risk estimation, assisting future allocation of prevention resources and strategic planning of mitigation programs. Using a 12-year (2002-2013) dataset containing the urban fire events in Nanjing, China, this research explores the spatial-temporal dynamics of urban fire incidents. A range of exploratory spatial data analysis (ESDA) approaches and tools, such as spatial kernel density and co-maps, are employed to examine the spatial, temporal and spatial-temporal variations of the fire events. Particular attention has been paid to two types of fire incidents: residential properties and local facilities, due to their relatively higher occurrence frequencies. The results demonstrated that the amount of urban fire has greatly increased in the last decade and spatial-temporal distribution of fire events vary among different incident types, which implies varying impact of potential influencing factors for further investigation.

A stochastic Forest Fire Model for future land cover scenarios assessment

NASA Astrophysics Data System (ADS)

D'Andrea, M.; Fiorucci, P.; Holmes, T. P.

2010-10-01

Land cover is affected by many factors including economic development, climate and natural disturbances such as wildfires. The ability to evaluate how fire regimes may alter future vegetation, and how future vegetation may alter fire regimes, would assist forest managers in planning management actions to be carried out in the face of anticipated socio-economic and climatic change. In this paper, we present a method for calibrating a cellular automata wildfire regime simulation model with actual data on land cover and wildfire size-frequency. The method is based on the observation that many forest fire regimes, in different forest types and regions, exhibit power law frequency-area distributions. The standard Drossel-Schwabl cellular automata Forest Fire Model (DS-FFM) produces simulations which reproduce this observed pattern. However, the standard model is simplistic in that it considers land cover to be binary - each cell either contains a tree or it is empty - and the model overestimates the frequency of large fires relative to actual landscapes. Our new model, the Modified Forest Fire Model (MFFM), addresses this limitation by incorporating information on actual land use and differentiating among various types of flammable vegetation. The MFFM simulation model was tested on forest types with Mediterranean and sub-tropical fire regimes. The results showed that the MFFM was able to reproduce structural fire regime parameters for these two regions. Further, the model was used to forecast future land cover. Future research will extend this model to refine the forecasts of future land cover and fire regime scenarios under climate, land use and socio-economic change.

Activity-Dependent Changes in the Firing Properties of Neocortical Fast-Spiking Interneurons in the Absence of Large Changes in Gene Expression

PubMed Central

Miller, Mark N.; Okaty, Benjamin W.; Kato, Saori; Nelson, Sacha B.

2010-01-01

The diverse cell types that comprise neocortical circuits each have characteristic integrative and firing properties that are specialized to perform specific functions within the network. Parvalbumin-positive fast-spiking (FS) interneurons are a particularly specialized cortical cell-type that controls the dynamics of ongoing activity and prevents runaway excitation by virtue of remarkably high firing rates, a feature that is permitted by narrow action potentials and the absence of spike-frequency adaptation. Although several neuronal intrinsic membrane properties undergo activity-dependent plasticity, the role of network activity in shaping and maintaining specialized, cell-type-specific firing properties is unknown. We tested whether the specialized firing properties of mature FS interneurons are sensitive to activity perturbations by inactivating a portion of motor cortex in vivo for 48 hours and measuring resulting plasticity of FS intrinsic and firing properties with whole-cell recording in acute slices. Many of the characteristic properties of FS interneurons, including non-adapting high-frequency spiking and narrow action potentials, were profoundly affected by activity deprivation both at an age just after maturation of FS firing properties and also a week after their maturation. Using microarray screening, we determined that although normal maturation of FS electrophysiological specializations is accompanied by large-scale transcriptional changes, the effects of deprivation on the same specializations involve more modest transcriptional changes, and may instead be primarily mediated by post-transcriptional mechanisms. PMID:21154910

Fire-induced Carbon Emissions and Regrowth Uptake in Western U.S. Forests: Documenting Variation Across Forest Types, Fire Severity, and Climate Regions

NASA Technical Reports Server (NTRS)

Ghimire, Bardan; Williams, Christopher A.; Collatz, George James; Vanderhoof, Melanie

2012-01-01

The forest area in the western United States that burns annually is increasing with warmer temperatures, more frequent droughts, and higher fuel densities. Studies that examine fire effects for regional carbon balances have tended to either focus on individual fires as examples or adopt generalizations without considering how forest type, fire severity, and regional climate influence carbon legacies. This study provides a more detailed characterization of fire effects and quantifies the full carbon impacts in relation to direct emissions, slow release of fire-killed biomass, and net carbon uptake from forest regrowth. We find important variations in fire-induced mortality and combustion across carbon pools (leaf, live wood, dead wood, litter, and duff) and across low- to high-severity classes. This corresponds to fire-induced direct emissions from 1984 to 2008 averaging 4 TgC/yr and biomass killed averaging 10.5 TgC/yr, with average burn area of 2723 sq km/yr across the western United States. These direct emission and biomass killed rates were 1.4 and 3.7 times higher, respectively, for high-severity fires than those for low-severity fires. The results show that forest regrowth varies greatly by forest type and with severity and that these factors impose a sustained carbon uptake legacy. The western U.S. fires between 1984 and 2008 imposed a net source of 12.3 TgC/yr in 2008, accounting for both direct fire emissions (9.5 TgC/yr) and heterotrophic decomposition of fire-killed biomass (6.1 TgC yr1) as well as contemporary regrowth sinks (3.3 TgC/yr). A sizeable trend exists toward increasing emissions as a larger area burns annually.

Landsat imagery evidences great recent land cover changes induced by wild fires in central Siberia*

NASA Astrophysics Data System (ADS)

Antamoshkina, O. A.; Trofimova, N. V.; Antamoshkin, O. A.

2016-04-01

The article discusses the methods of satellite image classification to determine general types of forest ecosystems, as well as the long-term monitoring of ecosystems changes using satellite imagery of medium spatial resolution and the daily data of space monitoring of active fires. The area of interest of this work is 100 km footprint of the Zotino Tall Tower Observatory (ZOTTO), located near the Zotino settlement, Krasnoyarsk region. The study area is located in the middle taiga subzone of Western Siberia, are presented by the left and right banks of the Yenisei river. For Landsat satellite imagery supervised classification by the maximum likelihood method was made using ground-based studies over the last fifteen years. The results are the identification of the 10 aggregated classes of land surface and composition of the study area thematic map. Operational satellite monitoring and analysis of spatial information about ecosystem in the 100-kilometer footprint of the ZOTTO tall tower allows to monitor the dynamics of forest disturbance by fire and logging over a long time period and to estimate changes in forest ecosystems of the study area. Data on the number and area of fires detected in the study region for the 2000-2014 received in the work. Calculations show that active fires have burned more than a quarter of the footprint area over the study period. Fires have a significant impact on the redistribution of classes of land surface. Area of all types of vegetation ecosystems declined dramatically under the influence of fires, whereas industrial logging does not impact seriously on it. The results obtained in our work indicate the highest occurrence of fires for lichen forest types within study region, probably due to their high natural fire danger, which is consistent with other studies. The least damage the fire caused to the wetland ecosystem due to high content of moisture and the presence of a large number of fire breaks in the form of open water.

Fire patterns in piñon and juniper land cover types in the Semiarid Western United States from 1984 through 2013

Treesearch

David I. Board; Jeanne C. Chambers; Richard F. Miller; Peter J. Weisberg

2018-01-01

Increases in area burned and fire size have been reported across a wide range of forest and shrubland types in the Western United States in recent decades, but little is known about potential changes in fire regimes of piñon and juniper land cover types. We evaluated spatio-temporal patterns of fire in piñon and juniper land cover types from the National Gap Analysis...

Database of in-situ field measurements for estimates of fuel consumption and fire emissions in Siberia

NASA Astrophysics Data System (ADS)

Kukavskaya, Elena; Conard, Susan; Buryak, Ludmila; Ivanova, Galina; Soja, Amber; Kalenskaya, Olga; Zhila, Sergey; Zarubin, Denis; Groisman, Pavel

2016-04-01

Wildfires show great variability in the amount of fuel consumed and carbon emitted to the atmosphere. Various types of models are used to calculate global or large scale regional fire emissions. However, in the databases used to estimate fuel consumptions, data for Russia are typically under-represented. Meanwhile, the differences in vegetation and fire regimes in the boreal forests in North America and Eurasia argue strongly for the need of regional ecosystem-specific data. For about 15 years we have been collecting field data on fuel loads and consumption in different ecosystem types of Siberia. We conducted a series of experimental burnings of varying fireline intensity in Scots pine and larch forests of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions. In addition, we examined wildfire behavior and effects in different vegetation types including Scots pine, Siberian pine, fir, birch, poplar, and larch-dominated forests; evergreen coniferous shrubs; grasslands, and peats. We investigated various ecosystem zones of Siberia (central and southern taiga, forest-steppe, steppe, mountains) in the different subjects of the Russian Federation (Krasnoyarsk Kray, Republic of Khakassia, Republic of Buryatia, Tuva Republic, Zabaikalsky Kray). To evaluate the impact of forest practices on fire emissions, burned and unburned logged sites and forest plantations were examined. We found large variations of fuel consumption and fire emission rates among different vegetation types depending on growing conditions, fire behavior characteristics and anthropogenic factors. Changes in the climate system result in an increase in fire frequency, area burned, the number of extreme fires, fire season length, fire season severity, and the number of ignitions from lightning. This leads to an increase of fire-related emissions of carbon to the atmosphere. The field measurement database we compiled is required for improving accuracy of existing biomass burning models and for use by air quality agencies in developing regional strategies to mitigate negative smoke impacts on human health and environment. The research was supported by the Grant of the President of the Russian Federation MK-4646.2015.5, RFBR grant # 15-04-06567, and the NASA LCLUC Program.

Mediterranean maquis fuel model development and mapping to support fire modeling

NASA Astrophysics Data System (ADS)

Bacciu, V.; Arca, B.; Pellizzaro, G.; Salis, M.; Ventura, A.; Spano, D.; Duce, P.

2009-04-01

Fuel load data and fuel model maps represent a critical issue for fire spread and behaviour modeling. The availability of accurate input data at different spatial and temporal scales can allow detailed analysis and predictions of fire hazard and fire effects across a landscape. Fuel model data are used in spatially explicit fire growth models to attain fire behaviour information for fuel management in prescribed fires, fire management applications, firefighters training, smoke emissions, etc. However, fuel type characteristics are difficult to be parameterized due to their complexity and variability: live and dead materials with different size contribute in different ways to the fire spread and behaviour. In the last decades, a strong help was provided by the use of remote sensing imagery at high spatial and spectral resolution. Such techniques are able to capture fine scale fuel distributions for accurate fire growth projections. Several attempts carried out in Europe were devoted to fuel classification and map characterization. In Italy, fuel load estimation and fuel model definition are still critical issues to be addressed due to the lack of detailed information. In this perspective, the aim of the present work was to propose an integrated approach based on field data collection, fuel model development and fuel model mapping to provide fuel models for the Mediterranean maquis associations. Field data needed for the development of fuel models were collected using destructive and non destructive measurements in experimental plots located in Northern Sardinia (Italy). Statistical tests were used to identify the main fuel types that were classified into four custom fuel models. Subsequently, a supervised classification by the Maximum Likelihood algorithm was applied on IKONOS images to identify and map the different types of maquis vegetation. The correspondent fuel model was then associated to each vegetation type to obtain the fuel model map. The results show the potential of this approach in achieving a reasonable accuracy in fuel model development and mapping; fine scale fuel model maps can be potentially helpful to obtain realistic predictions of fire behaviour and fire effects.

Early forest dynamics in stand-replacing fire patches in the northern Sierra Nevada, California, USA

Treesearch

Brandon M. Collins; Gary B. Roller

2013-01-01

There is considerable concern over the occurrence of stand-replacing fire in forest types historically associated with low- to moderate-severity fire. The concern is largely over whether contemporary levels of stand-replacing fire are outside the historical range of variability, and what natural forest recovery is in these forest types following stand-replacing fire....

Quantifying the fire regime distributions for severity in Yosemite National Park, California, USA

USGS Publications Warehouse

Thode, Andrea E.; van Wagtendonk, Jan W.; Miller, Jay D.; Quinn, James F.

2011-01-01

This paper quantifies current fire severity distributions for 19 different fire-regime types in Yosemite National Park, California, USA. Landsat Thematic Mapper remote sensing data are used to map burn severity for 99 fires (cumulatively over 97 000 ha) that burned in Yosemite over a 20-year period. These maps are used to quantify the frequency distributions of fire severity by fire-regime type. A classification is created for the resultant distributions and they are discussed within the context of four vegetation zones: the foothill shrub and woodland zone; the lower montane forest zone; the upper montane forest zone and the subalpine forest zone. The severity distributions can form a building block from which to discuss current fire regimes across the Sierra Nevada in California. This work establishes a framework for comparing the effects of current fires on our landscapes with our notions of how fires historically burned, and how current fire severity distributions differ from our desired future conditions. As this process is refined, a new set of information will be available to researchers and land managers to help understand how fire regimes have changed from the past and how we might attempt to manage them in the future.

Principal short-term findings of the National Fire and Fire Surrogate study

Treesearch

James McIver; Karen Erickson; Andrew Youngblood

2012-01-01

Principal findings of the National Fire and Fire Surrogate (FFS) study are presented in an annotated bibliography and summarized in tabular form by site, discipline (ecosystem component), treatment type, and major theme. Composed of 12 sites, the FFS is a comprehensive multidisciplinary experiment designed to evaluate the costs and ecological consequences of...

Demography: a tool for understanding the wildland-urban interface fire problems

Treesearch

James B. Davis

1989-01-01

Fire managers across the nation are confronting the rapidly developing problem created by movement of people into wildland areas, increasing what has been termed the wildland-urban interface. The problem is very complex from the standpoint of fire planning and management. To plan and manage more effectively, fire managers should identify three types of interface areas...

Spatial patterns of large natural fires in Sierra Nevada wilderness areas

USGS Publications Warehouse

Collins, B.M.; Kelly, M.; van Wagtendonk, J.W.; Stephens, S.L.

2007-01-01

The effects of fire on vegetation vary based on the properties and amount of existing biomass (or fuel) in a forest stand, weather conditions, and topography. Identifying controls over the spatial patterning of fire-induced vegetation change, or fire severity, is critical in understanding fire as a landscape scale process. We use gridded estimates of fire severity, derived from Landsat ETM+ imagery, to identify the biotic and abiotic factors contributing to the observed spatial patterns of fire severity in two large natural fires. Regression tree analysis indicates the importance of weather, topography, and vegetation variables in explaining fire severity patterns between the two fires. Relative humidity explained the highest proportion of total sum of squares throughout the Hoover fire (Yosemite National Park, 2001). The lowest fire severity corresponded with increased relative humidity. For the Williams fire (Sequoia/Kings Canyon National Parks, 2003) dominant vegetation type explains the highest proportion of sum of squares. Dominant vegetation was also important in determining fire severity throughout the Hoover fire. In both fires, forest stands that were dominated by lodgepole pine (Pinus contorta) burned at highest severity, while red fir (Abies magnifica) stands corresponded with the lowest fire severities. There was evidence in both fires that lower wind speed corresponded with higher fire severity, although the highest fire severity in the Williams fire occurred during increased wind speed. Additionally, in the vegetation types that were associated with lower severity, burn severity was lowest when the time since last fire was fewer than 11 and 17 years for the Williams and Hoover fires, respectively. Based on the factors and patterns identified, managers can anticipate the effects of management ignited and naturally ignited fires at the forest stand and the landscape levels. ?? 2007 Springer Science+Business Media, Inc.

46 CFR 162.028-5 - Independent laboratories: Listing.

Code of Federal Regulations, 2014 CFR

2014-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Extinguishers, Fire, Portable, Marine Type... or tests of portable fire extinguishers: (a) For dry chemical, CO2, water and foam type portable fire...

46 CFR 162.028-5 - Independent laboratories: Listing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Extinguishers, Fire, Portable, Marine Type... or tests of portable fire extinguishers: (a) For dry chemical, CO2, water and foam type portable fire...

46 CFR 162.028-5 - Independent laboratories: Listing.

Code of Federal Regulations, 2013 CFR

2013-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Extinguishers, Fire, Portable, Marine Type... or tests of portable fire extinguishers: (a) For dry chemical, CO2, water and foam type portable fire...

46 CFR 162.028-5 - Independent laboratories: Listing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Extinguishers, Fire, Portable, Marine Type... or tests of portable fire extinguishers: (a) For dry chemical, CO2, water and foam type portable fire...

46 CFR 162.028-5 - Independent laboratories: Listing.

Code of Federal Regulations, 2012 CFR

2012-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Extinguishers, Fire, Portable, Marine Type... or tests of portable fire extinguishers: (a) For dry chemical, CO2, water and foam type portable fire...

Intensifying postfire weather and biological invasion drive species loss in a Mediterranean-type biodiversity hotspot.

PubMed

Slingsby, Jasper A; Merow, Cory; Aiello-Lammens, Matthew; Allsopp, Nicky; Hall, Stuart; Kilroy Mollmann, Hayley; Turner, Ross; Wilson, Adam M; Silander, John A

2017-05-02

Prolonged periods of extreme heat or drought in the first year after fire affect the resilience and diversity of fire-dependent ecosystems by inhibiting seed germination or increasing mortality of seedlings and resprouting individuals. This interaction between weather and fire is of growing concern as climate changes, particularly in systems subject to stand-replacing crown fires, such as most Mediterranean-type ecosystems. We examined the longest running set of permanent vegetation plots in the Fynbos of South Africa (44 y), finding a significant decline in the diversity of plots driven by increasingly severe postfire summer weather events (number of consecutive days with high temperatures and no rain) and legacy effects of historical woody alien plant densities 30 y after clearing. Species that resprout after fire and/or have graminoid or herb growth forms were particularly affected by postfire weather, whereas all species were sensitive to invasive plants. Observed differences in the response of functional types to extreme postfire weather could drive major shifts in ecosystem structure and function such as altered fire behavior, hydrology, and carbon storage. An estimated 0.5 °C increase in maximum temperature tolerance of the species sets unique to each survey further suggests selection for species adapted to hotter conditions. Taken together, our results show climate change impacts on biodiversity in the hyperdiverse Cape Floristic Region and demonstrate an important interaction between extreme weather and disturbance by fire that may make flammable ecosystems particularly sensitive to climate change.

Managing the human component of fire regimes: lessons from Africa.

PubMed

Archibald, Sally

2016-06-05

Human impacts on fire regimes accumulated slowly with the evolution of modern humans able to ignite fires and manipulate landscapes. Today, myriad voices aim to influence fire in grassy ecosystems to different ends, and this is complicated by a colonial past focused on suppressing fire and preventing human ignitions. Here, I review available evidence on the impacts of people on various fire characteristics such as the number and size of fires, fire intensity, fire frequency and seasonality of fire in African grassy ecosystems, with the intention of focusing the debate and identifying areas of uncertainty. Humans alter seasonal patterns of fire in grassy systems but tend to decrease total fire emissions: livestock have replaced fire as the dominant consumer in many parts of Africa, and fragmented landscapes reduce area burned. Humans alter the season and time of day when fires occur, with important implications for fire intensity, tree-grass dynamics and greenhouse gas (GHG) emissions. Late season fires are more common when fire is banned or illegal: these later fires are far more intense but emit fewer GHGs. The types of fires which preserve human livelihoods and biodiversity are not always aligned with the goal of reducing GHG concentrations. Current fire management challenges therefore involve balancing the needs of a large rural population against national and global perspectives on the desirability of different types of fire, but this cannot happen unless the interests of all parties are equally represented. In the future, Africa is expected to urbanize and land use to intensify, which will imply different trajectories for the continent's fire regimes.This article is part of the themed issue 'The interaction of fire and mankind. © 2016 The Author(s).

Managing the human component of fire regimes: lessons from Africa

PubMed Central

Archibald, Sally

2016-01-01

Human impacts on fire regimes accumulated slowly with the evolution of modern humans able to ignite fires and manipulate landscapes. Today, myriad voices aim to influence fire in grassy ecosystems to different ends, and this is complicated by a colonial past focused on suppressing fire and preventing human ignitions. Here, I review available evidence on the impacts of people on various fire characteristics such as the number and size of fires, fire intensity, fire frequency and seasonality of fire in African grassy ecosystems, with the intention of focusing the debate and identifying areas of uncertainty. Humans alter seasonal patterns of fire in grassy systems but tend to decrease total fire emissions: livestock have replaced fire as the dominant consumer in many parts of Africa, and fragmented landscapes reduce area burned. Humans alter the season and time of day when fires occur, with important implications for fire intensity, tree–grass dynamics and greenhouse gas (GHG) emissions. Late season fires are more common when fire is banned or illegal: these later fires are far more intense but emit fewer GHGs. The types of fires which preserve human livelihoods and biodiversity are not always aligned with the goal of reducing GHG concentrations. Current fire management challenges therefore involve balancing the needs of a large rural population against national and global perspectives on the desirability of different types of fire, but this cannot happen unless the interests of all parties are equally represented. In the future, Africa is expected to urbanize and land use to intensify, which will imply different trajectories for the continent's fire regimes. This article is part of the themed issue ‘The interaction of fire and mankind. PMID:27216516

The calcium-binding protein parvalbumin modulates the firing 1 properties of the reticular thalamic nucleus bursting neurons.

PubMed

Albéri, Lavinia; Lintas, Alessandra; Kretz, Robert; Schwaller, Beat; Villa, Alessandro E P

2013-06-01

The reticular thalamic nucleus (RTN) of the mouse is characterized by an overwhelming majority of GABAergic neurons receiving afferences from both the thalamus and the cerebral cortex and sending projections mainly on thalamocortical neurons. The RTN neurons express high levels of the "slow Ca(2+) buffer" parvalbumin (PV) and are characterized by low-threshold Ca(2+) currents, I(T). We performed extracellular recordings in ketamine/xylazine anesthetized mice in the rostromedial portion of the RTN. In the RTN of wild-type and PV knockout (PVKO) mice we distinguished four types of neurons characterized on the basis of their firing pattern: irregular firing (type I), medium bursting (type II), long bursting (type III), and tonically firing (type IV). Compared with wild-type mice, we observed in the PVKOs the medium bursting (type II) more frequently than the long bursting type and longer interspike intervals within the burst without affecting the number of spikes. This suggests that PV may affect the firing properties of RTN neurons via a mechanism associated with the kinetics of burst discharges. Ca(v)3.2 channels, which mediate the I(T) currents, were more localized to the somatic plasma membrane of RTN neurons in PVKO mice, whereas Ca(v)3.3 expression was similar in both genotypes. The immunoelectron microscopy analysis showed that Ca(v)3.2 channels were localized at active axosomatic synapses, thus suggesting that the differential localization of Ca(v)3.2 in the PVKOs may affect bursting dynamics. Cross-correlation analysis of simultaneously recorded neurons from the same electrode tip showed that about one-third of the cell pairs tended to fire synchronously in both genotypes, independent of PV expression. In summary, PV deficiency does not affect the functional connectivity between RTN neurons but affects the distribution of Ca(v)3.2 channels and the dynamics of burst discharges of RTN cells, which in turn regulate the activity in the thalamocortical circuit.

The effect of repeated firings on the color change of dental ceramics using different glazing methods

PubMed Central

Yılmaz, Kerem; Ozturk, Caner

2014-01-01

PURPOSE Surface color is one of the main criteria to obtain an ideal esthetic. Many factors such as the type of the material, surface specifications, number of firings, firing temperature and thickness of the porcelain are all important to provide an unchanged surface color in dental ceramics. The aim of this study was to evaluate the color changes in dental ceramics according to the material type and glazing methods, during the multiple firings. MATERIALS AND METHODS Three different types of dental ceramics (IPS Classical metal ceramic, Empress Esthetic and Empress 2 ceramics) were used in the study. Porcelains were evaluated under five main groups according to glaze and natural glaze methods. Color changes (ΔE) and changes in color parameters (ΔL, Δa, Δb) were determined using colorimeter during the control, the first, third, fifth, and seventh firings. The statistical analysis of the results was performed using ANOVA and Tukey test. RESULTS The color changes which occurred upon material-method-firing interaction were statistically significant (P<.05). ΔE, ΔL, Δa and Δb values also demonstrated a negative trend. The MC-G group was less affected in terms of color changes compared to other groups. In all-ceramic specimens, the surface color was significantly affected by multiple firings. CONCLUSION Firing detrimentally affected the structure of the porcelain surface and hence caused fading of the color and prominence of yellow and red characters. Compressible all-ceramics were remarkably affected by repeated firings due to their crystalline structure. PMID:25551001

Modeling mechanisms of vegetation change due to fire in a semi-arid ecosystem

USGS Publications Warehouse

White, J.D.; Gutzwiller, K.J.; Barrow, W.C.; Randall, L.J.; Swint, P.

2008-01-01

Vegetation growth and community composition in semi-arid environments is determined by water availability and carbon assimilation mechanisms specific to different plant types. Disturbance also impacts vegetation productivity and composition dependent on area affected, intensity, and frequency factors. In this study, a new spatially explicit ecosystem model is presented for the purpose of simulating vegetation cover type changes associated with fire disturbance in the northern Chihuahuan Desert region. The model is called the Landscape and Fire Simulator (LAFS) and represents physiological activity of six functional plant types incorporating site climate, fire, and seed dispersal routines for individual grid cells. We applied this model for Big Bend National Park, Texas, by assessing the impact of wildfire on the trajectory of vegetation communities over time. The model was initialized and calibrated based on landcover maps derived from Landsat-5 Thematic Mapper data acquired in 1986 and 1999 coupled with plant biomass measurements collected in the field during 2000. Initial vegetation cover change analysis from satellite data showed shrub encroachment during this time period that was captured in the simulated results. A synthetic 50-year climate record was derived from historical meteorological data to assess system response based on initial landcover conditions. This simulation showed that shrublands increased to the detriment of grass and yucca-ocotillo vegetation cover types indicating an ecosystem-level trajectory for shrub encroachment. Our analysis of simulated fires also showed that fires significantly reduced site biomass components including leaf area, stem, and seed biomass in this semi-arid ecosystem. In contrast to other landscape simulation models, this new model incorporates detailed physiological responses of functional plant types that will allow us to simulated the impact of increased atmospheric CO2 occurring with climate change coupled with fire disturbance. Simulations generated from this model are expected to be the subject of subsequent studies on landscape dynamics with specific regard to prediction of wildlife distributions associated with fire management and climate change.

Carbachol induces burst firing of dopamine cells in the ventral tegmental area by promoting calcium entry through L-type channels in the rat

PubMed Central

Zhang, Lei; Liu, Yudan; Chen, Xihua

2005-01-01

Enhanced activity of the central dopamine system has been implicated in many psychiatric disorders including schizophrenia and addiction. Besides terminal mechanisms that boost dopamine levels at the synapse, the cell body of dopamine cells enhances terminal dopamine concentration through encoding action potentials in bursts. This paper presents evidence that burst firing of dopamine cells in the ventral tegmental area was under cholinergic control using nystatin-perforated patch clamp recording from slice preparations. The non-selective cholinergic agonist carbachol excited the majority of recorded neurones, an action that was not affected by blocking glutamate and GABA ionotropic receptors. Twenty per cent of dopamine cells responded to carbachol with robust bursting, an effect mediated by both muscarinic and nicotinic cholinoceptors postsynaptically. Burst firing induced as such was completely dependent on calcium entry as it could be blocked by cadmium and more specifically the L-type blocker nifedipine. In the presence of the sodium channel blocker tetrodotoxin, carbachol induced membrane potential oscillation that had similar kinetics and frequency as burst firing cycles and could also be blocked by cadmium and nifedipine. Direct activation of the L-type channel with Bay K8644 induced strong bursting which could be blocked by nifedipine but not by depleting internal calcium stores. These results indicate that carbachol increases calcium entry into the postsynaptic cell through L-type channels to generate calcium-dependent membrane potential oscillation and burst firing. This could establish the L-type channel as a target for modulating the function of the central dopamine system in disease conditions. PMID:16081481

Interactions among livestock grazing, vegetation type, and fire behavior in the Murphy wildland fire complex in Idaho and Nevada, July 2007

USDA-ARS?s Scientific Manuscript database

A series of wildland fires were ignited by lightning in sagebrush and grassland communities near the Idaho-Nevada border southwest of Twin Falls, Idaho in July 2007. The fires burned for over two weeks and encompassed more than 650,000 acres. A team of scientists, habitat specialists, and land manag...

Smoke in a new era of fire

Treesearch

Rachel White; Paul Hessburg; Sim Larkin; Morgan Varner

2017-01-01

Smoke from fire can sharply reduce air quality by releasing particulate matter, one of the most dangerous types of air pollution for human health. A third of U.S. households have someone sensitive to smoke. Minimizing the amount and impact of smoke is a high priority for land managers and regulators. One tool for achieving that goal is prescribed fire. Prescribed fire...

Effect of a long-term fire retardant (Fire Trol 934) on the germination of nine Mediterranean-type shrub species.

PubMed

Cruz, Alberto; Serrano, Marián; Navarro, Esther; Luna, Belén; Moreno, José M

2005-12-01

Fire Trol 934 is a long-term fire retardant commonly used in fire prevention and extinction. Our objective was to determine the effect of this chemical on seed germination of nine plant species from Mediterranean-type shrublands, where these chemicals are potentially used. Seeds were exposed to five different Fire Trol concentrations, (0 (control) to 10%, on a log scale) and monitored in a germination chamber for nine weeks. Seeds from four Cistus species were subjected to an additional heat treatment that simulated thermal scarification caused by fire. Retardant exposure caused a significant decrease in total germination in all species, and exposure to the highest Fire Trol concentration (10%) resulted in complete inhibition of germination. However, the sensitivity to Fire Trol varied across species and this differential species sensitivity may potentially lead to different impacts in the soil seed banks depending on whether sites are burned or unburned. Exposure to Fire Trol 934 may affect recruitment of shrubland species particularly during dry autumns, due to limited leaching of these chemicals from the soil surface. Consequently, its use should be avoided in sites where particularly sensitive plant species are present. Copyright (c) 2005 Wiley Periodicals, Inc.

[Drivers of human-caused fire occurrence and its variation trend under climate change in the Great Xing'an Mountains, Northeast China].

PubMed

Li, Shun; Wu, Zhi Wei; Liang, Yu; He, Hong Shi

2017-01-01

The Great Xing'an Mountains are an important boreal forest region in China with high frequency of fire occurrences. With climate change, this region may have a substantial change in fire frequency. Building the relationship between spatial pattern of human-caused fire occurrence and its influencing factors, and predicting the spatial patterns of human-caused fires under climate change scenarios are important for fire management and carbon balance in boreal forests. We employed a spatial point pattern model to explore the relationship between the spatial pattern of human-caused fire occurrence and its influencing factors based on a database of historical fire records (1967-2006) in the Great Xing'an Mountains. The fire occurrence time was used as dependent variable. Nine abiotic (annual temperature and precipitation, elevation, aspect, and slope), biotic (vegetation type), and human factors (distance to the nearest road, road density, and distance to the nearest settlement) were selected as explanatory variables. We substituted the climate scenario data (RCP 2.6 and RCP 8.5) for the current climate data to predict the future spatial patterns of human-caused fire occurrence in 2050. Our results showed that the point pattern progress (PPP) model was an effective tool to predict the future relationship between fire occurrence and its spatial covariates. The climatic variables might significantly affect human-caused fire occurrence, while vegetation type, elevation and human variables were important predictors of human-caused fire occurrence. The human-caused fire occurrence probability was expected to increase in the south of the area, and the north and the area along the main roads would also become areas with high human-caused fire occurrence. The human-caused fire occurrence would increase by 72.2% under the RCP 2.6 scenario and by 166.7% under the RCP 8.5 scenario in 2050. Under climate change scenarios, the spatial patterns of human-caused fires were mainly influenced by the climate and human factors.

High-fire-risk behavior in critical fire areas

Treesearch

William S. Folkman

1977-01-01

Observations of fire-related behavior of wildland visitors were made in three types of areas-wilderness, established campground, and built-up commercial and residential areas-within the San Bernardino National Forest, California. Interviews were conducted with all persons so observed. Types of fire-related behavior differed markedly from one area to another, as did the...

Handheld Delivery System for Modified Boron-Type Fire Extinguishment Agent

DTIC Science & Technology

1993-11-01

was to develop and test a handheld portable delivery system for use with the modified boron-type fire extinguishing agent for metal fires . B...BACKGROUND A need exists for an extinguishing agent and accompanying delivery system that are effective against complex geometry metal fires . A modified...agent and its delivery system have proven effective against complex geometry metal fires containing up to 200 pounds of magnesium metal. Further

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.

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.

Intrinsic Cellular Properties and Connectivity Density Determine Variable Clustering Patterns in Randomly Connected Inhibitory Neural Networks

PubMed Central

Rich, Scott; Booth, Victoria; Zochowski, Michal

2016-01-01

The plethora of inhibitory interneurons in the hippocampus and cortex play a pivotal role in generating rhythmic activity by clustering and synchronizing cell firing. Results of our simulations demonstrate that both the intrinsic cellular properties of neurons and the degree of network connectivity affect the characteristics of clustered dynamics exhibited in randomly connected, heterogeneous inhibitory networks. We quantify intrinsic cellular properties by the neuron's current-frequency relation (IF curve) and Phase Response Curve (PRC), a measure of how perturbations given at various phases of a neurons firing cycle affect subsequent spike timing. We analyze network bursting properties of networks of neurons with Type I or Type II properties in both excitability and PRC profile; Type I PRCs strictly show phase advances and IF curves that exhibit frequencies arbitrarily close to zero at firing threshold while Type II PRCs display both phase advances and delays and IF curves that have a non-zero frequency at threshold. Type II neurons whose properties arise with or without an M-type adaptation current are considered. We analyze network dynamics under different levels of cellular heterogeneity and as intrinsic cellular firing frequency and the time scale of decay of synaptic inhibition are varied. Many of the dynamics exhibited by these networks diverge from the predictions of the interneuron network gamma (ING) mechanism, as well as from results in all-to-all connected networks. Our results show that randomly connected networks of Type I neurons synchronize into a single cluster of active neurons while networks of Type II neurons organize into two mutually exclusive clusters segregated by the cells' intrinsic firing frequencies. Networks of Type II neurons containing the adaptation current behave similarly to networks of either Type I or Type II neurons depending on network parameters; however, the adaptation current creates differences in the cluster dynamics compared to those in networks of Type I or Type II neurons. To understand these results, we compute neuronal PRCs calculated with a perturbation matching the profile of the synaptic current in our networks. Differences in profiles of these PRCs across the different neuron types reveal mechanisms underlying the divergent network dynamics. PMID:27812323

Fire modeling in a nonventilated corridor

NASA Astrophysics Data System (ADS)

Lulea, Marius Dorin; Iordache, Vlad; Năstase, Ilinca

2018-02-01

The main objective of this study was to determine the effect of fire in a nonventilated corridor. A real-scale model of a corridor has been modeled in Fire Dynamics Simulator(F.D.S.) in order to determine the evolution of indoor temperatures, the visibility and the oxygen quantities during a fire. The start time of a sprinkler has also been determined. The use of sprinklers in buildings has become a necessity and a requirement imposed by technical norms. The provision of this type of installation has become a common feature in buildings with a high fire risk, with two main effects: fire extinction and protection of structural and partition elements from high temperatures[15]. The ultimate goal is to ensure optimal conditions for saving the building users, intervention teams and maintaining the stability of the building. Low temperatures and good visibility on the escape routes during a fire are the basic conditions to ensure the optimal evacuation of users.

Holocene fire activity and vegetation response in South-Eastern Iberia

NASA Astrophysics Data System (ADS)

Gil-Romera, Graciela; Carrión, José S.; Pausas, Juli G.; Sevilla-Callejo, Miguel; Lamb, Henry F.; Fernández, Santiago; Burjachs, Francesc

2010-05-01

Since fire has been recognized as an essential disturbance in Mediterranean landscapes, the study of long-term fire ecology has developed rapidly. We have reconstructed a sequence of vegetation dynamics and fire changes across south-eastern Iberia by coupling records of climate, fire, vegetation and human activities. We calculated fire activity anomalies (FAAs) in relation to 3 ka cal BP for 10-8 ka cal BP, 6 ka cal BP, 4 ka cal BP and the present. For most of the Early to the Mid-Holocene uneven, but low fire events were the main vegetation driver at high altitudes where broadleaved and coniferous trees presented a highly dynamic post-fire response. At mid-altitudes in the mainland Segura Mountains, fire activity remained relatively stable, at similar levels to recent times. We hypothesize that coastal areas, both mountains and lowlands, were more fire-prone landscapes as biomass was more likely to have accumulated than in the inland regions, triggering regular fire events. The wet and warm phase towards the Mid-Holocene (between ca 8 and 6 ka cal BP) affected the whole region and promoted the spread of mesophytic forest co-existing with Pinus, as FAAs appear strongly negative at 6 ka cal BP, with a less important role of fire. Mid and Late Holocene landscapes were shaped by an increasing aridity trend and the rise of human occupation, especially in the coastal mountains where forest disappeared from ca 2 ka cal BP. Mediterranean-type vegetation (evergreen oaks and Pinus pinaster- halepensis types) showed the fastest post-fire vegetation dynamics over time.

Broadleaf deciduous forest counterbalanced the direct effect of climate on Holocene fire regime in hemiboreal/boreal region (NE Europe)

NASA Astrophysics Data System (ADS)

Feurdean, Angelica; Veski, Siim; Florescu, Gabriela; Vannière, Boris; Pfeiffer, Mirjam; O'Hara, Robert B.; Stivrins, Normunds; Amon, Leeli; Heinsalu, Atko; Vassiljev, Jüri; Hickler, Thomas

2017-08-01

Disturbances by fire are essential for the functioning of boreal/hemiboreal forests, but knowledge of long-term fire regime dynamics is limited. We analysed macrocharcoal morphologies and pollen of a sediment record from Lake Lielais Svētiņu (eastern Latvia), and in conjunction with fire traits analysis present the first record of Holocene variability in fire regime, fuel sources and fire types in boreal forests of the Baltic region. We found a phase of moderate to high fire activity during the cool and moist early (mean fire return interval; mFRI of ∼280 years; 11,700-7500 cal yr BP) and the late (mFRI of ∼190 years; 4500-0 cal yr BP) Holocene and low fire activity (mFRI of ∼630 years) during the Holocene Thermal Optimum (7500-4500 cal yr BP). Charcoal morphotypes and the pollen record show the predominance of frequent surface fires, occasionally transitioning to the crown during Pinus sylvestris-Betula boreal forests and less frequent surface fires during the dominance of temperate deciduous forests. In contrast to the prevailing opinion that fires in boreal forests are mostly low to moderate severity surface fires, we found evidence for common occurrence of stand-replacing crown fires in Picea abies canopy. Our results highlight that charcoal morphotypes analysis allows for distinguishing the fuel types and surface from crown fires, therefore significantly advancing our interpretation of fire regime. Future warmer temperatures and increase in the frequency of dry spells and abundant biomass accumulation can enhance the fire risk on the one hand, but will probably promote the expansion of broadleaf deciduous forests to higher latitudes, on the other hand. By highlighting the capability of broadleaf deciduous forests to act as fire-suppressing landscape elements, our results suggest that fire activity may not increase in the Baltic area under future climate change.

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.

Fires. A Joint Publication for U.S. Artillery Professionals. May-June 2011

DTIC Science & Technology

2011-05-01

DATE MAY 2011 2. REPORT TYPE 3. DATES COVERED 00-05-2011 to 00-06-2011 4. TITLE AND SUBTITLE Fires. A Joint Publication for U.S. Artillery...celebration in front of the original School of Fire, which dates back to 1911. (Photo by Keith Pannell, U.S. Army) 3 sill-www.army.mil/firesbulletin... date ) in the photograph - for example: “SGT Joe B. Smith, C/2-20 Fires, 4th Fires Brigade, fires the M777A2 howitzer during unit qualification

Development of a Standard Test Scenario to Evaluate the Effectiveness of Portable Fire Extinguishers on Lithium-ion Battery Fires

NASA Technical Reports Server (NTRS)

Juarez, Alfredo; Harper, Susan A.; Hirsch, David B.; Carriere, Thierry

2013-01-01

Many sources of fuel are present aboard current spacecraft, with one especially hazardous source of stored energy: lithium ion batteries. Lithium ion batteries are a very hazardous form of fuel due to their self-sustaining combustion once ignited, for example, by an external heat source. Batteries can become extremely energetic fire sources due to their high density electrochemical energy content that may, under duress, be violently converted to thermal energy and fire in the form of a thermal runaway. Currently, lithium ion batteries are the preferred types of batteries aboard international spacecraft and therefore are routinely installed, collectively forming a potentially devastating fire threat to a spacecraft and its crew. Currently NASA is developing a fine water mist portable fire extinguisher for future use on international spacecraft. As its development ensues, a need for the standard evaluation of various types of fire extinguishers against this potential threat is required to provide an unbiased means of comparing between fire extinguisher technologies and ranking them based on performance.

Defining old growth for fire-adapted forests of the Western United States

Treesearch

Merrill R. Kaufmann; Daniel Binkley; Peter Z. Fule; Johnson Marlin; Scott L. Stephens; Thomas W. Swetnam

2007-01-01

There are varying definitions of old-growth forests because of differences in environment and differing fire influence across the Intermountain West. Two general types of forests reflect the role of fire: 1) forests shaped by natural changes in structure and species makeup-plant succession-that are driven by competitive differences among species and individual trees...

46 CFR 199.175 - Survival craft and rescue boat equipment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... breakage-resistant material. (9) Fire extinguisher. The fire extinguisher must be approved under approval series 162.028. The fire extinguisher must be type B-C, size II, or larger. Two type B-C, size I fire... portions of the hull. (4) Bucket. The bucket must be made of corrosion-resistant material and should either...

Fires following bark beetles: Factors controlling severity and disturbance interactions in ponderosa pine

Treesearch

Carolyn H. Sieg; Rodman R. Linn; Francois Pimont; Chad M. Hoffman; Joel D. McMillin; Judith Winterkamp; L. Scott Baggett

2017-01-01

Previous studies have suggested that bark beetles and fires can be interacting disturbances, whereby bark beetle-caused tree mortality can alter the risk and severity of subsequent wildland fires. However, there remains considerable uncertainty around the type and magnitude of the interaction between fires following bark beetle attacks, especially in drier forest types...

Fuel and fire behavior in high-elevation five-needle pines affected by mountain pine beetle

Treesearch

Michael J. Jenkins

2011-01-01

Bark beetle-caused tree mortality in conifer forests affects the quantity and quality of forest fuels and has long been assumed to increase fire hazard and potential fire behavior. In reality, bark beetles and their effects on fuel accumulation and subsequent fire hazard have only recently been described. We have extensively sampled fuels in three conifer forest types...

Modeling vegetation mosaics in sub-alpine Tasmania under various fire regimes

Treesearch

Gabriel I. Yospin; Samuel W. Wood; Andres Holz; David M. J. S. Bowman; Robert E. Keane; Cathy Whitlock

2015-01-01

Western Tasmania, Australia contains some of the highest levels of biological endemism of any temperate region in the world, including vegetation types that are conservation priorities: fire-sensitive rainforest dominated by endemic conifer species in the genus Athrotaxis; and firetolerant buttongrass moorlands. Current management focuses on fire suppression,...

Fire protection for launch facilities using machine vision fire detection

NASA Astrophysics Data System (ADS)

Schwartz, Douglas B.

1993-02-01

Fire protection of critical space assets, including launch and fueling facilities and manned flight hardware, demands automatic sensors for continuous monitoring, and in certain high-threat areas, fast-reacting automatic suppression systems. Perhaps the most essential characteristic for these fire detection and suppression systems is high reliability; in other words, fire detectors should alarm only on actual fires and not be falsely activated by extraneous sources. Existing types of fire detectors have been greatly improved in the past decade; however, fundamental limitations of their method of operation leaves open a significant possibility of false alarms and restricts their usefulness. At the Civil Engineering Laboratory at Tyndall Air Force Base in Florida, a new type of fire detector is under development which 'sees' a fire visually, like a human being, and makes a reliable decision based on known visual characteristics of flames. Hardware prototypes of the Machine Vision (MV) Fire Detection System have undergone live fire tests and demonstrated extremely high accuracy in discriminating actual fires from false alarm sources. In fact, this technology promises to virtually eliminate false activations. This detector could be used to monitor fueling facilities, launch towers, clean rooms, and other high-value and high-risk areas. Applications can extend to space station and in-flight shuttle operations as well; fiber optics and remote camera heads enable the system to see around obstructed areas and crew compartments. The capability of the technology to distinguish fires means that fire detection can be provided even during maintenance operations, such as welding.

Fire protection for launch facilities using machine vision fire detection

NASA Technical Reports Server (NTRS)

Schwartz, Douglas B.

1993-01-01

Fire protection of critical space assets, including launch and fueling facilities and manned flight hardware, demands automatic sensors for continuous monitoring, and in certain high-threat areas, fast-reacting automatic suppression systems. Perhaps the most essential characteristic for these fire detection and suppression systems is high reliability; in other words, fire detectors should alarm only on actual fires and not be falsely activated by extraneous sources. Existing types of fire detectors have been greatly improved in the past decade; however, fundamental limitations of their method of operation leaves open a significant possibility of false alarms and restricts their usefulness. At the Civil Engineering Laboratory at Tyndall Air Force Base in Florida, a new type of fire detector is under development which 'sees' a fire visually, like a human being, and makes a reliable decision based on known visual characteristics of flames. Hardware prototypes of the Machine Vision (MV) Fire Detection System have undergone live fire tests and demonstrated extremely high accuracy in discriminating actual fires from false alarm sources. In fact, this technology promises to virtually eliminate false activations. This detector could be used to monitor fueling facilities, launch towers, clean rooms, and other high-value and high-risk areas. Applications can extend to space station and in-flight shuttle operations as well; fiber optics and remote camera heads enable the system to see around obstructed areas and crew compartments. The capability of the technology to distinguish fires means that fire detection can be provided even during maintenance operations, such as welding.

The Greek National Observatory of Forest Fires (NOFFi)

NASA Astrophysics Data System (ADS)

Tompoulidou, Maria; Stefanidou, Alexandra; Grigoriadis, Dionysios; Dragozi, Eleni; Stavrakoudis, Dimitris; Gitas, Ioannis Z.

2016-08-01

Efficient forest fire management is a key element for alleviating the catastrophic impacts of wildfires. Overall, the effective response to fire events necessitates adequate planning and preparedness before the start of the fire season, as well as quantifying the environmental impacts in case of wildfires. Moreover, the estimation of fire danger provides crucial information required for the optimal allocation and distribution of the available resources. The Greek National Observatory of Forest Fires (NOFFi)—established by the Greek Forestry Service in collaboration with the Laboratory of Forest Management and Remote Sensing of the Aristotle University of Thessaloniki and the International Balkan Center—aims to develop a series of modern products and services for supporting the efficient forest fire prevention management in Greece and the Balkan region, as well as to stimulate the development of transnational fire prevention and impacts mitigation policies. More specifically, NOFFi provides three main fire-related products and services: a) a remote sensing-based fuel type mapping methodology, b) a semi-automatic burned area mapping service, and c) a dynamically updatable fire danger index providing mid- to long-term predictions. The fuel type mapping methodology was developed and applied across the country, following an object-oriented approach and using Landsat 8 OLI satellite imagery. The results showcase the effectiveness of the generated methodology in obtaining highly accurate fuel type maps on a national level. The burned area mapping methodology was developed as a semi-automatic object-based classification process, carefully crafted to minimize user interaction and, hence, be easily applicable on a near real-time operational level as well as for mapping historical events. NOFFi's products can be visualized through the interactive Fire Forest portal, which allows the involvement and awareness of the relevant stakeholders via the Public Participation GIS (PPGIS) tool.

MUNICIPAL WASTE COMBUSTION ASSESSMENT: FOSSIL FUEL CO-FIRING

EPA Science Inventory

The report identifies refuse derived fuel (RDF) processing operations and various RDF types; describes such fossil fuel co-firing techniques as coal fired spreader stokers, pulverized coal wall fired boilers, pulverized coal tangentially fired boilers, and cyclone fired boilers; ...

Large-Scale Controls and Characteristics of Fire Activity in Central Chile, 2001-2015

NASA Astrophysics Data System (ADS)

McWethy, D. B.; Pauchard, A.; García, R.; Holz, A.; González, M.; Veblen, T. T.; Stahl, J.

2016-12-01

In recent decades, fire activity has increased in many ecosystems worldwide, even where fuel conditions and natural ignitions historically limited fire activity, and this increase begs questions of whether climate change, land-use change, and/or altered vegetation are responsible. Increased frequency of large fires in these settings has been attributed to drier-than-average summers and longer fire seasons as well as fuel accumulation related to ENSO events, raising concerns about the trajectory of post-fire vegetation dynamics and future fire regimes. In temperate and Mediterranean forests of central Chile, recent large fires associated with altered ecosystems, climate variability and land-use change highlight the risk and hazard of increasing fire activity yet the causes and consequences are poorly understood. To better understand characteristics of recent fire activity, key drivers of fire occurrence and the spatial probability of wildfire we examined the relationship between fire activity derived from MODIS satellite imagery and biophysical, land-cover and land-use variables. The probability of fire occurrence and annual area burned was best predicted by seasonal precipitation, annual temperature and land cover type. The likelihood of fire occurrence was greatest in Matorral shrublands, agricultural lands (including pasture lands) and Pinus and Eucalyptus plantations, highlighting the importance of vegetation type and fuel flammability as a critical control on fire activity. Our results suggest that land-use change responsible for the widespread presence of highly flammable vegetation and projections for continued warming and drying will likely combine to promote the occurrence of large fires in central Chile in the future.

Reconstructing grassland fire history using sedimentary charcoal: Considering count, size and shape.

PubMed

Leys, Berangere A; Commerford, Julie L; McLauchlan, Kendra K

2017-01-01

Fire is a key Earth system process, with 80% of annual fire activity taking place in grassland areas. However, past fire regimes in grassland systems have been difficult to quantify due to challenges in interpreting the charcoal signal in depositional environments. To improve reconstructions of grassland fire regimes, it is essential to assess two key traits: (1) charcoal count, and (2) charcoal shape. In this study, we quantified the number of charcoal pieces in 51 sediment samples of ponds in the Great Plains and tested its relevance as a proxy for the fire regime by examining 13 potential factors influencing charcoal count, including various fire regime components (e.g. the fire frequency, the area burned, and the fire season), vegetation cover and pollen assemblages, and climate variables. We also quantified the width to length (W:L) ratio of charcoal particles, to assess its utility as a proxy of fuel types in grassland environments by direct comparison with vegetation cover and pollen assemblages. Our first conclusion is that charcoal particles produced by grassland fires are smaller than those produced by forest fires. Thus, a mesh size of 120μm as used in forested environments is too large for grassland ecosystems. We recommend counting all charcoal particles over 60μm in grasslands and mixed grass-forest environments to increase the number of samples with useful data. Second, a W:L ratio of 0.5 or smaller appears to be an indicator for fuel types, when vegetation surrounding the site is before composed of at least 40% grassland vegetation. Third, the area burned within 1060m of the depositional environments explained both the count and the area of charcoal particles. Therefore, changes in charcoal count or charcoal area through time indicate a change in area burned. The fire regimes of grassland systems, including both human and climatic influences on fire behavior, can be characterized by long-term charcoal records.

Reconstructing grassland fire history using sedimentary charcoal: Considering count, size and shape

PubMed Central

Leys, Berangere A.; Commerford, Julie L.; McLauchlan, Kendra K.

2017-01-01

Fire is a key Earth system process, with 80% of annual fire activity taking place in grassland areas. However, past fire regimes in grassland systems have been difficult to quantify due to challenges in interpreting the charcoal signal in depositional environments. To improve reconstructions of grassland fire regimes, it is essential to assess two key traits: (1) charcoal count, and (2) charcoal shape. In this study, we quantified the number of charcoal pieces in 51 sediment samples of ponds in the Great Plains and tested its relevance as a proxy for the fire regime by examining 13 potential factors influencing charcoal count, including various fire regime components (e.g. the fire frequency, the area burned, and the fire season), vegetation cover and pollen assemblages, and climate variables. We also quantified the width to length (W:L) ratio of charcoal particles, to assess its utility as a proxy of fuel types in grassland environments by direct comparison with vegetation cover and pollen assemblages. Our first conclusion is that charcoal particles produced by grassland fires are smaller than those produced by forest fires. Thus, a mesh size of 120μm as used in forested environments is too large for grassland ecosystems. We recommend counting all charcoal particles over 60μm in grasslands and mixed grass-forest environments to increase the number of samples with useful data. Second, a W:L ratio of 0.5 or smaller appears to be an indicator for fuel types, when vegetation surrounding the site is before composed of at least 40% grassland vegetation. Third, the area burned within 1060m of the depositional environments explained both the count and the area of charcoal particles. Therefore, changes in charcoal count or charcoal area through time indicate a change in area burned. The fire regimes of grassland systems, including both human and climatic influences on fire behavior, can be characterized by long-term charcoal records. PMID:28448597

Utilizing NASA Airborne Data to Investigate the Influence of Fuel Type on Biomass Burning Aerosol Properties

NASA Astrophysics Data System (ADS)

Odwuor, A.; Corr, C.; Griffin, R. J.; Pusede, S.; Anderson, B.; Beyersdorf, A. J.; Campuzano Jost, P.; Chen, G.; Day, D. A.; Diskin, G. S.; Jimenez, J. L.; Moore, R.; Nault, B.; Schwarz, J. P.; Shook, M.; Thornhill, K. L., II; Winstead, E.; Armin, W.; Ziemba, L. D.

2017-12-01

Climate models and satellite aerosol classification retrievals rely on well-characterized aerosol optical properties (e.g., scattering and absorption coefficients) that vary with aerosol type. However, generalized parameterizations of aerosol optical properties are weakened by actual variability in aerosol chemical and physical properties that arises from factors independent of aerosol source (e.g., meteorology). This is particularly true for biomass burning (BB) aerosol, which can vary in composition and size depending on burn conditions (e.g., smoldering versus flaming) and fuel. This work investigates the relationships between BB aerosol chemical, physical, and optical properties and fuel. We compare BB aerosol measured in fire plumes associated with distinct fuel types sampled during three NASA airborne research campaigns: boreal forest fires during the Arctic Research of the Troposphere from Aircraft and Satellites (ARCTAS) mission in Saskatchewan, Canada in July 2008; agricultural fires during the Studies of Emissions and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys (SEAC4RS) over the continental U.S. in August/September 2013; and scrubland fires during the Student Airborne Research Program (SARP) mission in Southern California, U.S. in June 2016. Mean modified combustion efficiency values between 0.9 and 0.92 for the agricultural plumes and between 0.92 and 0.99 for the boreal and scrubland plumes indicate a significant flaming component to these fires. Despite similarities in burn conditions, SSA at 550nm was consistently lower for the agricultural and scrubland fires ( 0.92) compared to the boreal forest ( 0.96). While the ratio of black carbon to organic aerosol (OA) was similar among fires, differences in the OA were noted; f44/f60 ratios derived from Aerosol Mass Spectrometer OA measurements were consistently higher (>5) in scrubland and agricultural fires compared to boreal forest fires (<5). This suggests the amount of oxidized OA relative to fresh BB aerosol in fire plumes under flaming conditions may vary with fuel type and influence plume optical properties. The relationship between size distributions and optical properties is also explored in this work, with particular attention on the role of the coarse mode in aerosol absorption.

Comparison of public safety provider injury rates.

PubMed

Suyama, Joe; Rittenberger, Jon C; Patterson, P Daniel; Hostler, David

2009-01-01

During normal operations, public safety personnel may become injured, leading them to seek medical care and possible time off. Examining the nature and patterns of injury may help to identify preventive health measures for all public safety personnel and address specific needs of each discipline based on actual risk. Objective. To determine the types and severity of injuries encountered by public safety personnel during routine work conditions within a single urban population. De-identified workers' compensation data for emergency medical services (EMS), fire, and police providers from one urban center between January 1, 2005, and May 31, 2007, were examined. Data included type of injury, severity of injury, and date of event. Severity was categorized as follows: lost time (type 1), medical evaluation (type 2), report only (type 3), restricted duty (type 4), and not reported (type 5). Analysis of variance (ANOVA) and a pairwise t-test between groups with a Bonferroni correction was performed to determine the relative risk of injuries between groups. During the 29-month interval, an average workforce of 850 firefighters, 194 EMS providers, and 850 police officers were employed. A total of 1,295 workers' compensation events were documented, with 243 (18%) reported from EMS, 477 (36%) from fire, and 608 (46%) from police. Type 1 injuries were more common in fire (39%) and police (38%) than EMS (23%). EMS had higher rates of lost work (type 1) and medical evaluations (type 2) than both fire and police. Workers' compensation events common to all bureaus were minor trauma (76%) and exposures to blood-borne pathogens (12%). Minor traumatic injuries, mostly associated with axial musculoskeletal strains and extremity injuries, were responsible for the majority of injuries resulting in missed work. Injuries more common in a specific bureau included motor vehicle crashes and gunshot wounds (police) and cardiovascular disease, burns, and heat illness (fire). Public safety personnel are affected by both profession-specific and non-profession-specific injuries. Overall, EMS has higher rates of missed time and medical evaluations than both fire and police. These data highlight the need to make direct comparisons of various public safety personnel bureaus using a common time interval and locale in order to rationally plan interventions and apply resources.

Aviation Engine Test Facilities (AETF) fire protection study

NASA Astrophysics Data System (ADS)

Beller, R. C.; Burns, R. E.; Leonard, J. T.

1989-07-01

An analysis is presented to the effectiveness of various types of fire fighting agents in extinguishing the kinds of fires anticipated in Aviation Engine Test Facilities (AETF), otherwise known as Hush Houses. The agents considered include Aqueous Film-Forming Foam, Halon 1301, Halon 1211 and water. Previous test work has shown the rapidity with which aircraft, especially high performance aircraft, can be damaged by fire. Based on this, tentative criteria for this evaluation included a maximum time of 20 s from fire detection to extinguishment and a period of 30 min in which the agent would prevent reignition. Other issues examined included: toxicity, corrosivity, ease of personnel egress, system reliability, and cost effectiveness. The agents were evaluated for their performance in several fire scenarios, including: under frame fire, major engine fire, engine disintegration fire, high-volume pool fire with simultaneous spill fire, internal electrical fire, and runaway engine fire.

Comparative Analysis of Fusion Center Outreach to Fire and EMS Agencies

DTIC Science & Technology

2015-12-01

ANALYSIS OF FUSION CENTER OUTREACH TO FIRE AND EMS AGENCIES by Scott E. Goldstein December 2015 Thesis Advisor: Fathali Moghaddam Second...REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE COMPARATIVE ANALYSIS OF FUSION CENTER OUTREACH TO FIRE AND EMS AGENCIES 5...public release; distribution is unlimited 12b. DISTRIBUTION CODE A 13. ABSTRACT (maximum 200 words) Fire and EMS responders have had little

Species Composition and Fire: Non-Additive Mixture Effects on Ground Fuel Flammability

PubMed Central

van Altena, Cassandra; van Logtestijn, Richard S. P.; Cornwell, William K.; Cornelissen, Johannes H. C.

2012-01-01

Diversity effects on many aspects of ecosystem function have been well documented. However, fire is an exception: fire experiments have mainly included single species, bulk litter, or vegetation, and, as such, the role of diversity as a determinant of flammability, a crucial aspect of ecosystem function, is poorly understood. This study is the first to experimentally test whether flammability characteristics of two-species mixtures are non-additive, i.e., differ from expected flammability based on the component species in monospecific fuel. In standardized fire experiments on ground fuels, including monospecific fuels and mixtures of five contrasting subarctic plant fuel types in a controlled laboratory environment, we measured flame speed, flame duration, and maximum temperature. Broadly half of the mixture combinations showed non-additive effects for these flammability indicators; these were mainly enhanced dominance effects for temporal dynamics – fire speed and duration. Fuel types with the more flammable value for a characteristic determined the rate of fire speed and duration of the whole mixture; in contrast, maximum temperature of the fire was determined by the biomass-weighted mean of the mixture. These results suggest that ecological invasions by highly flammable species may have effects on ground-fire dynamics well out of proportion to their biomass. PMID:22639656

California Spotted Owl (Strix occidentalis occidentalis) habitat use patterns in a burned landscape

USGS Publications Warehouse

Eyes, Stephanie; Roberts, Susan L.; Johnson, Matthew D.

2017-01-01

Fire is a dynamic ecosystem process of mixed-conifer forests of the Sierra Nevada, but there is limited scientific information addressing wildlife habitat use in burned landscapes. Recent studies have presented contradictory information regarding the effects of stand-replacing wildfires on Spotted Owls (Strix occidentalis) and their habitat. While fire promotes heterogeneous forest landscapes shown to be favored by owls, high severity fire may create large canopy gaps that can fragment the closed-canopy habitat preferred by Spotted Owls. We used radio-telemetry to determine whether foraging California Spotted Owls (S. o. occidentalis) in Yosemite National Park, California, USA, showed selection for particular fire severity patch types within their home ranges. Our results suggested that Spotted Owls exhibited strong habitat selection within their home ranges for locations near the roost and edge habitats, and weak selection for lower fire severity patch types. Although owls selected high contrast edges with greater relative probabilities than low contrast edges, we did not detect a statistical difference between these probabilities. Protecting forests from stand-replacing fires via mechanical thinning or prescribed fire is a priority for management agencies, and our results suggest that fires of low to moderate severity can create habitat conditions within California Spotted Owls' home ranges that are favored for foraging.

Influences of prior wildfires on vegetation response to subsequent fire in a reburned Southwestern landscape.

PubMed

Coop, Jonathan D; Parks, Sean A; McClernan, Sarah R; Holsinger, Lisa M

2016-03-01

Large and severe wildfires have raised concerns about the future of forested landscapes in the southwestern United States, especially under repeated burning. In 2011, under extreme weather and drought conditions, the Las Conchas fire burned over several previous burns as well as forests not recently exposed to fire. Our purpose was to examine the influences of prior wildfires on plant community composition and structure, subsequent burn severity, and vegetation response. To assess these relationships, we used satellite-derived measures of burn severity and a nonmetric multidimensional scaling of pre- and post- Las Conchas field samples. Earlier burns were associated with shifts from forested sites to open savannas and meadows, oak scrub, and ruderal communities. These non-forested vegetation types exhibited both resistance to subsequent fire, measured by reduced burn severity, and resilience to reburning, measured by vegetation recovery relative to forests not exposed to recent prior fire. Previous shifts toward non-forested states were strongly reinforced by reburning. Ongoing losses of forests and their ecological values confirm the need for restoration interventions. However, given future wildfire and climate projections, there may also be opportunities presented by transformations toward fire-resistant and resilient vegetation types within portions of the landscape.

Fire Impact on Phytomass and Carbon Emissions in the Forests of Siberia

NASA Astrophysics Data System (ADS)

Ivanova, Galina A.; Zhila, Sergei V.; Ivanov, Valery A.; Kovaleva, Nataly M.; Kukavskaya, Elena A.; Platonova, Irina A.; Conard, Susan G.

2014-05-01

Siberian boreal forests contribute considerably to the global carbon budget, since they take up vast areas, accumulate large amount of carbon, and are sensitive to climatic changes. Fire is the main forest disturbance factor, covering up to millions of hectares of boreal forests annually, of which the majority is in Siberia. Carbon emissions released from phytomass burning influence atmospheric chemistry and global carbon cycling. Changing climate and land use influence the number and intensity of wildfires, forest state, and productivity, as well as global carbon balance. Fire effects on forest overstory, subcanopy woody layer, and ground vegetation phytomass were estimated on sites in light-conifer forests of the Central Siberia as a part of the project "The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia" supported by NASA (NEESPI). This study focuses on collecting quantitative data and modeling the influence of fires of varying intensity on fire emissions, carbon budget, and ecosystem processes in coniferous stands. Fires have a profound impact on forest-atmospheric carbon exchange and transform forests from carbon sinks to carbon sources lasting long after the time of burning. Our long-term experiments allowed us to identify vegetation succession patterns in taiga Scots pine stands after fires of known behavior. Estimating fire contributions to the carbon budget requires consideration of many factors, including vegetation type and fire type and intensity. Carbon emissions were found to depend on fire intensity and weather. In the first several years after fire, the above-ground phytomass appeared to be strongly controlled by fire intensity. However, the influence of burning intensity on organic matter accumulation was found to decrease with time.

Comparison of particulate lead levels for different ammunition types used with the M16 rifle. Final report, July 1987-June 1988

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

Hoke, S.H.; Beard, A.S.; Brueggemann, E.E.

1988-07-01

Airborne lead generated during firing of conventional ammunition has lead to health concerns at indoor firing ranges. This study compares the relative amounts of airborne lead produced by the M16 rifle firing the M193 standard M16 5.56-mm conventional ammunition, the M862 5.56-mm plastic training ammunition, and the conventional caliber .22 rifle cartridge. Both breech and breech-plus-muzzle lead emissions were determined for each type of ammunition.

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.

Comparison of Interglacial fire dynamics in Southern Africa

NASA Astrophysics Data System (ADS)

Brücher, Tim; Daniau, Anne-Laure

2016-04-01

Responses of fire activity to a change in climate are still uncertain and biases exist by integrating this non-linear process into global modeling of the Earth system. Warming and regional drying can force fire activity in two opposite directions: an increase in fire in fuel supported ecosystems or a fire reduction in fuel-limited ecosystems. Therefore, climate variables alone can not be used to estimate the fire risk because vegetation variability is an important determinant of fire dynamics and responds itself to change in climate. Southern Africa (south of 20°S) paleofire history reconstruction obtained from the analysis of microcharcoal preserved in a deep-sea core located off Namibia reveals changes of fire activity on orbital timescales in the precession band. In particular, increase in fire is observed during glacial periods, and reduction of fire during interglacials such as the Eemian and the Holocene. The Holocene was characterized by even lower level of fire activity than Eemian. Those results suggest the alternance of grass-fueled fires during glacials driven by increase in moisture and the development of limited fueled ecosystems during interglacials characterized by dryness. Those results question the simulated increase in the fire risk probability projected for this region under a warming and drying climate obtained by Pechony and Schindell (2010). To explore the validity of the hypotheses we conducted a data-model comparison for both interglacials from 126.000 to 115.000 BP for the Eemian and from 8.000 to 2.000 BP for the Holocene. Data out of a transient, global modeling study with a Vegetation-Fire model of full complexity (JSBACH) is used, driven by a Climate model of intermediate complexity (CLIMBER). Climate data like precipitation and temperature as well as vegetation data like soil moisture, productivity (NPP) on plant functional type level are used to explain trends in fire activity. The comparison of trends in fire activity during the Eemian (126.000 to 120.000 BP) and the Holocene (8.000 to 200 BP) shows an increase in fire data and in simulated fire. Lower level of fire during the Holocene than Eemian can be explained by differences due to unequal trends in vegetation as a result of climate forcing due to orbital changes: while woody type vegetation plays a major role during the Eemian, the Holocene is influenced by grass land. From the modelling perspective changes in the seasonal precipitation drives the vegetation pattern.

A strategic assessment of crown fire hazard in Montana: potential effectiveness and costs of hazard reduction treatments.

Treesearch

Carl E. Fiedler; Charles E. Keegan; Christopher W. Woodall; Todd A. Morgan

2004-01-01

Estimates of crown fire hazard are presented for existing forest conditions in Montana by density class, structural class, forest type, and landownership. Three hazard reduction treatments were evaluated for their effectiveness in treating historically fire-adapted forests (ponderosa pine (Pinus ponderosa Dougl. ex Laws.), Douglas-fir (...

24 CFR 232.510 - Commitment and commitment fee.

Code of Federal Regulations, 2013 CFR

2013-04-01

... of Fire Safety Equipment Fees and Charges § 232.510 Commitment and commitment fee. (a) Issuance of... setting forth the terms and conditions upon which the fire safety loan will be insured. (b) Type of... installation of the fire safety equipment, as determined by the Secretary of HHS. (c) Term of commitment. (1...

24 CFR 232.510 - Commitment and commitment fee.

Code of Federal Regulations, 2012 CFR

2012-04-01

... of Fire Safety Equipment Fees and Charges § 232.510 Commitment and commitment fee. (a) Issuance of... setting forth the terms and conditions upon which the fire safety loan will be insured. (b) Type of... installation of the fire safety equipment, as determined by the Secretary of HHS. (c) Term of commitment. (1...

24 CFR 232.510 - Commitment and commitment fee.

Code of Federal Regulations, 2014 CFR

2014-04-01

... of Fire Safety Equipment Fees and Charges § 232.510 Commitment and commitment fee. (a) Issuance of... setting forth the terms and conditions upon which the fire safety loan will be insured. (b) Type of... installation of the fire safety equipment, as determined by the Secretary of HHS. (c) Term of commitment. (1...

Ca currents activated by spontaneous firing and synaptic disinhibition in neurons of the cerebellar nuclei

PubMed Central

Zheng, Nan; Raman, Indira M.

2009-01-01

In neurons of the cerebellar nuclei, long-term potentiation of EPSCs is induced by high-frequency synaptic excitation by mossy fibers followed by synaptic inhibition by Purkinje cells. Induction requires activation of synaptic receptors as well as voltage-gated Ca channels. To examine how Purkinje-mediated inhibition of nuclear neurons affects Ca levels during plasticity-inducing stimuli, we have combined electrophysiology, Ca imaging, and pharmacology of cerebellar nuclear neurons in mouse cerebellar slices. We find that spontaneous firing generates tonic Ca signals in both somata and dendrites, which drop during 500-ms, 100-Hz trains of Purkinje IPSPs or hyperpolarizing steps. Although the presence of low-voltage-activated (T-type) Ca channels in nuclear neurons has fostered the inference that disinhibition activates these channels, synaptic inhibition with a physiological ECl (−75 mV) fails to hyperpolarize neurons sufficiently for T-type channels to recover substantially. Consequently, after IPSPs, Ca signals return to baseline, although firing is accelerated by ∼20 Hz for ∼300 ms. Only after hyperpolarizations beyond ECl does Ca rise gradually beyond baseline, as firing further exceeds spontaneous rates. Cd2+ (100 μM), which nearly eliminates L-type, N-type, P/Q-type, and R-type Ca currents while sparing about half the T-type current, prevents Ca changes during and after hyperpolarizations to ECl. Thus, high-frequency IPSPs in cerebellar nuclear neurons evoke little post-inhibitory current through T-type channels. Instead, inhibition regulates Ca levels simply by preventing action potentials, which usually permit Ca influx through high-voltage-activated channels. The decreases and restoration of Ca levels associated with Purkinje-mediated inhibition are likely to contribute to synaptic plasticity. PMID:19657035

Climate- and disturbance-driven changes in vegetation composition and structure limit future potential carbon storage in the Greater Yellowstone Ecosystem, USA

NASA Astrophysics Data System (ADS)

Henne, Paul D.; Hawbaker, Todd J.; Zhao, Feng; Huang, Chengquan; Berryman, Erin M.; Zhu, Zhiliang

2016-04-01

The Greater Yellowstone Ecosystem (GYE) provides unique opportunities to understand how changing climate, land use, and disturbance affect ecosystem carbon balance. The GYE is one of the largest, most intact ecosystems in the United States. However, distinct management histories on National Park, National Forest, and private lands, elevational climate gradients, and variable fire activity, have created a mosaic of stand ages and forest types. It is uncertain how greenhouse forcing may alter the carbon balance of the GYE. Whereas increasing temperatures may enhance productivity and perpetuate the GYE as a carbon sink, climate-driven increases in fire frequency may offset productivity gains by limiting biomass accumulation. We investigated how changes in fire frequency and size may affect vegetation dynamics and carbon sequestration potential in the GYE using the LANDIS-II dynamic landscape vegetation model. LANDIS-II provides sufficient spatial resolution to capture landscape-level variation in forest biomass and forest types (i.e. 90 × 90 m grid cells), but can integrate disturbance regimes and vegetation dynamics across the entire GYE (92,000 km2). We initiated our simulations with biomass and stand conditions that preceded the exceptional 1988 fire, when 16% of the GYE burned. We inferred the biomass, species abundances, and stand demographics of each model cell by combining satellite imagery with forest inventory data, and developed two fire regime scenarios from historical fire records. We developed a historic wildfire scenario with infrequent fires by excluding 1988 from our calibration of fire sizes and frequencies, and a future scenario with more frequent and larger fires by including 1988 in our calibrations. Fire frequency increased in all forest types in our future scenario, with a 152% increase in the annual forest area burned relative to observed area burned during recent decades. However, the changes in fire frequency varied among forest types, with the largest increases in lodgepole pine (Pinus contorta; 332% increase) and spruce/fir (Picea engelmannii, Abies lasiocarpa; 243% increase) stands. In model runs with the historic fire regime, average stand age and live biomass remained consistent with pre-1988 values during the 200-year simulation period; biomass increased significantly only in recently-logged areas. In contrast, a marked shift to younger stands with lower biomass occurred in the future fire scenario. Average stand age declined from 112 years to 31 years in lodgepole pine stands, and from 191 years to 65 years in spruce/fir stands, with consequent reductions in living biomass. A smaller shift in stand age was simulated for douglas-fir (Pseudotsuga menziesii) stands (i.e. 121 to 92 years). These fire-driven changes in stand age and biomass coincided with important shifts in species abundances. Specifically, lodgepole pine stands replaced large areas previously dominated by spruce and fir. Our results suggest that the potential for increasing the amount of fossil fuel emissions offset by carbon sequestration on public lands in the American West is limited by ongoing changes in disturbance regimes. Instead, land managers may need to consider strategies to adapt to climate change impacts.

Influence of forest management alternatives and land type on susceptibility to fire in northern Wisconsin, USA

Treesearch

Eric J. Gustafson; Patrick A. Zollner; Brian R. Sturtevant; S. He Hong; David J. Mladenoff

2004-01-01

We used the LANDIS disturbance and succession model to study the effects of six alternative vegetation management scenarios on forest succession and the subsequent risk of canopy fire on a 2791 km2 landscape in northern Wisconsin, USA. The study area is a mix of fire-prone and fire-resistant land types. The alternatives vary the spatial...

How fuel treatment types, locations, and amounts impact landscape-scale fire behavior and carbon dynamics

Treesearch

Christopher A. Dicus; Kevin J. Osborne

2015-01-01

When managing for fire across a large landscape, the types of fuel treatments, the locations of treatments, and the percentage of the landscape being treated should all interact to impact not only potential fire size, but also carbon dynamics across that landscape. To investigate these interactions, we utilized a forest growth model (FVS-FFE) and fire simulation...

Firefighter noise exposure during training activities and general equipment use.

PubMed

Root, Kyle S; Schwennker, Catherine; Autenrieth, Daniel; Sandfort, Delvin R; Lipsey, Tiffany; Brazile, William J

2013-01-01

Multiple noise measurements were taken on 6 types of fire station equipment and 15 types of emergency response vehicle-related equipment used by firefighters during routine and emergency operations at 10 fire stations. Five of the six types of fire station equipment, when measured at a distance of one meter and ear level, emitted noise equal to or greater than 85 dBA, including lawn maintenance equipment, snow blowers, compressors, and emergency alarms. Thirteen of 15 types of equipment located on the fire engines emitted noise levels equal to or greater than 85 dBA, including fans, saws, alarms, and extrication equipment. In addition, noise measurements were taken during fire engine operations, including the idling vehicle, vehicle sirens, and water pumps. Results indicated that idling fire-engine noise levels were below 85 dBA; however, during water pump and siren use, noise levels exceeded 85 dBA, in some instances, at different locations around the trucks where firefighters would be stationed during emergency operations. To determine if the duration and use of fire fighting equipment was sufficient to result in overexposures to noise during routine training activities, 93 firefighter personal noise dosimetry samples were taken during 10 firefighter training activities. Two training activities per sampling day were monitored during each sampling event, for a mean exposure time of 70 min per day. The noise dosimetry samples were grouped based on job description to compare noise exposures between the different categories of job tasks commonly associated with fire fighting. The three job categories were interior, exterior, and engineering. Mean personal dosimetry results indicated that the average noise exposure was 78 dBA during the training activities that lasted 70 min on average. There was no significant difference in noise exposure between each of the three job categories. Although firefighters routinely use equipment and emergency response vehicles that can produce hazardous levels of noise, this study showed that the average noise levels experienced by firefighters was below generally accepted guidelines.

Kv4.2 Mediates Histamine Modulation of Preoptic Neuron Activity and Body Temperature

PubMed Central

Sethi, Jasmine; Sanchez-Alavez, Manuel; Tabarean, Iustin V.

2011-01-01

Histamine regulates arousal, circadian rhythms, and thermoregulation. Activation of H3 histamine receptors expressed by preoptic GABAergic neurons results in a decrease of their firing rate and hyperthermia. Here we report that an increase in the A-type K+ current in preoptic GABAergic neurons in response to activation of H3 histamine receptors results in decreased firing rate and hyperthermia in mice. The Kv4.2 subunit is required for these actions in spite of the fact that Kv4.2−/− preoptic GABAergic neurons display A-type currents and firing characteristics similar to those of wild-type neurons. This electrical remodeling is achieved by robust upregulation of the expression of the Kv4.1 subunit and of a delayed rectifier current. Dynamic clamp experiments indicate that enhancement of the A-type current by a similar amount to that induced by histamine is sufficient to mimic its robust effect on firing rates. These data indicate a central role played by the Kv4.2 subunit in histamine regulation of body temperature and its interaction with pERK1/2 downstream of the H3 receptor. We also reveal that this pathway provides a mechanism for selective modulation of body temperature at the beginning of the active phase of the circadian cycle. PMID:22220205

Novel Tools in Determining the Physiological Demands and Nutritional Practices of Ontario FireRangers during Fire Deployments

PubMed Central

Robertson, A. H.; Larivière, C.; Leduc, C. R.; McGillis, Z.; Eger, T.; Godwin, A.; Larivière, M.; Dorman, S. C.

2017-01-01

Introduction The seasonal profession of wildland fire fighting in Canada requires individuals to work in harsh environmental conditions that are physically demanding. The purpose of this study was to use novel technologies to evaluate the physiological demands and nutritional practices of Canadian FireRangers during fire deployments. Methods Participants (n = 21) from a northern Ontario Fire Base volunteered for this study and data collection occurred during the 2014 fire season and included Initial Attack (IA), Project Fire (P), and Fire Base (B) deployments. Deployment-specific energy demands and physiological responses were measured using heart-rate variability (HRV) monitoring devices (Zephyr BioHarness3 units). Food consumption behaviour and nutrient quantity and quality were captured using audio-video food logs on iPod Touches and analyzed by NutriBase Pro 11 software. Results Insufficient kilocalories were consumed relative to expenditure for all deployment types. Average daily kilocalories consumed: IA: 3758 (80% consumption rate); P: 2945±888.8; B: 2433±570.8. Average daily kilocalorie expenditure: IA: 4538±106.3; P: 4012±1164.8; B: 2842±649.9. The Average Macronutrient Distribution Range (AMDR) for protein was acceptable: 22–25% (across deployment types). Whereas the AMDR for fat and carbohydrates were high: 40–50%; and low: 27–37% respectively, across deployment types. Conclusions This study is the first to use the described methodology to simultaneously evaluate energy expenditures and nutritional practices in an occupational setting. The results support the use of HRV monitoring and video-food capture, in occupational field settings, to assess job demands. FireRangers expended the most energy during IA, and the least during B deployments. These results indicate the need to develop strategies centered on maintaining physical fitness and improving food practices. PMID:28107380

Ponderosa pine snag densities following multiple fires in the Gila Wilderness, New Mexico

USGS Publications Warehouse

Holden, Z.A.; Morgan, P.; Rollins, M.G.; Wright, R.G.

2006-01-01

Fires create and consume snags (standing dead trees), an important structural and ecological component of ponderosa pine forests. The effects of repeated fires on snag densities in ponderosa pine forests of the southwestern USA have not been studied. Line intercept sampling was used to estimate snag densities in areas of the Gila Wilderness that had burned one to three times under Wildland Fire Use for Resource Benefit (WFU), a fire management policy implemented since 1974 aimed at restoring natural fire regimes. Twenty randomly located transects were measured in areas burned since 1946; six in once-burned areas, six in twice-burned areas and eight in thrice-burned areas. The mean density ?? standard errors of large (>47.5 cm dbh) snags for areas that burned once, twice and thrice was 7.0 ?? 2.7, 4.4 ?? 1.1 and 4.1 ?? 1.3 snags/ha, respectively. Differences in snag densities between once- and multiple-burned areas were significant (F-test; p < 0.05). There was no significant difference in density of large snags between twice- and thrice-burned areas. Proportions of type 1 snags (recently created) were higher in once- and twice-burned areas than in areas that burned three times, likely reflecting high tree mortality and snag recruitment resulting from an initial entry fire. Type 3 snags (charred by previous fire) were more abundant in areas that burned multiple times. The lack of differences in snag densities between areas that burned two and three times suggests that repeated fires leave many snags standing. The increasing proportion of type 3 snags with repeated fires supports this conclusion. ?? 2005 Elsevier B.V. All rights reserved.

Novel Tools in Determining the Physiological Demands and Nutritional Practices of Ontario FireRangers during Fire Deployments.

PubMed

Robertson, A H; Larivière, C; Leduc, C R; McGillis, Z; Eger, T; Godwin, A; Larivière, M; Dorman, S C

2017-01-01

The seasonal profession of wildland fire fighting in Canada requires individuals to work in harsh environmental conditions that are physically demanding. The purpose of this study was to use novel technologies to evaluate the physiological demands and nutritional practices of Canadian FireRangers during fire deployments. Participants (n = 21) from a northern Ontario Fire Base volunteered for this study and data collection occurred during the 2014 fire season and included Initial Attack (IA), Project Fire (P), and Fire Base (B) deployments. Deployment-specific energy demands and physiological responses were measured using heart-rate variability (HRV) monitoring devices (Zephyr BioHarness3 units). Food consumption behaviour and nutrient quantity and quality were captured using audio-video food logs on iPod Touches and analyzed by NutriBase Pro 11 software. Insufficient kilocalories were consumed relative to expenditure for all deployment types. Average daily kilocalories consumed: IA: 3758 (80% consumption rate); P: 2945±888.8; B: 2433±570.8. Average daily kilocalorie expenditure: IA: 4538±106.3; P: 4012±1164.8; B: 2842±649.9. The Average Macronutrient Distribution Range (AMDR) for protein was acceptable: 22-25% (across deployment types). Whereas the AMDR for fat and carbohydrates were high: 40-50%; and low: 27-37% respectively, across deployment types. This study is the first to use the described methodology to simultaneously evaluate energy expenditures and nutritional practices in an occupational setting. The results support the use of HRV monitoring and video-food capture, in occupational field settings, to assess job demands. FireRangers expended the most energy during IA, and the least during B deployments. These results indicate the need to develop strategies centered on maintaining physical fitness and improving food practices.

Cell-type-dependent action potentials and voltage-gated currents in mouse fungiform taste buds.

PubMed

Kimura, Kenji; Ohtubo, Yoshitaka; Tateno, Katsumi; Takeuchi, Keita; Kumazawa, Takashi; Yoshii, Kiyonori

2014-01-01

Taste receptor cells fire action potentials in response to taste substances to trigger non-exocytotic neurotransmitter release in type II cells and exocytotic release in type III cells. We investigated possible differences between these action potentials fired by mouse taste receptor cells using in situ whole-cell recordings, and subsequently we identified their cell types immunologically with cell-type markers, an IP3 receptor (IP3 R3) for type II cells and a SNARE protein (SNAP-25) for type III cells. Cells not immunoreactive to these antibodies were examined as non-IRCs. Here, we show that type II cells and type III cells fire action potentials using different ionic mechanisms, and that non-IRCs also fire action potentials with either of the ionic mechanisms. The width of action potentials was significantly narrower and their afterhyperpolarization was deeper in type III cells than in type II cells. Na(+) current density was similar in type II cells and type III cells, but it was significantly smaller in non-IRCs than in the others. Although outwardly rectifying current density was similar between type II cells and type III cells, tetraethylammonium (TEA) preferentially suppressed the density in type III cells and the majority of non-IRCs. Our mathematical model revealed that the shape of action potentials depended on the ratio of TEA-sensitive current density and TEA-insensitive current one. The action potentials of type II cells and type III cells under physiological conditions are discussed. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

A review of fire interactions and mass fires

Treesearch

Mark A. Finney; Sara S. McAllister

2011-01-01

The character of a wildland fire can change dramatically in the presence of another nearby fire. Understanding and predicting the changes in behavior due to fire-fire interactions cannot only be life-saving to those on the ground, but also be used to better control a prescribed fire to meet objectives. In discontinuous fuel types, such interactions may elicit fire...

KChIP1 modulation of Kv4.3-mediated A-type K(+) currents and repetitive firing in hippocampal interneurons.

PubMed

Bourdeau, M L; Laplante, I; Laurent, C E; Lacaille, J-C

2011-03-10

Neuronal A-type K(+) channels regulate action potential waveform, back-propagation and firing frequency. In hippocampal CA1 interneurons located at the stratum lacunosum-moleculare/radiatum junction (LM/RAD), Kv4.3 mediates A-type K(+) currents and a Kv4 β-subunit of the Kv channel interacting protein (KChIP) family, KChIP1, appears specifically expressed in these cells. However, the functional role of this accessory subunit in A-type K(+) currents and interneuron excitability remains largely unknown. Thus, first we studied KChIP1 and Kv4.3 channel interactions in human embryonic kidney 293 (HEK293) cells and determined that KChIP1 coexpression modulated the biophysical properties of Kv4.3 A-type currents (faster recovery from inactivation, leftward shift of activation curve, faster rise time and slower decay) and this modulation was selectively prevented by KChIP1 short interfering RNA (siRNA) knockdown. Next, we evaluated the effects of KChIP1 down-regulation by siRNA on A-type K(+) currents in LM/RAD interneurons in slice cultures. Recovery from inactivation of A-type K(+) currents was slower after KChIP1 down-regulation but other properties were unchanged. In addition, down-regulation of KChIP1 levels did not affect action potential waveform and firing, but increased firing frequency during suprathreshold depolarizations, indicating that KChIP1 regulates interneuron excitability. The effects of KChIP1 down-regulation were cell-specific since CA1 pyramidal cells that do not express KChIP1 were unaffected. Overall, our findings suggest that KChIP1 interacts with Kv4.3 in LM/RAD interneurons, enabling faster recovery from inactivation of A-type currents and thus promoting stronger inhibitory control of firing during sustained activity. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Untrained Forward Observer (UFO) Translator for Call for Fire

DTIC Science & Technology

2013-09-01

release; distribution is unlimited UNTRAINED FORWARD OBSERVER ( UFO ) TRANSLATOR FOR CALL FOR FIRE by Regan R. King September 2013 Thesis...DATE September 2013 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE UNTRAINED FORWARD OBSERVER ( UFO ) TRANSLATOR FOR CALL...application, which we call the Untrained Forward Observer ( UFO ) Translator, capable of assisting untrained observers in performing Call for Fire by asking a

Burn severity of areas reburned by wildfires in the Gila National Forest, New Mexico, USA

Treesearch

Zachary A. Holden; Penelope Morgan; Andrew T. Hudak

2010-01-01

We describe satellite-inferred burn severity patterns of areas that were burned and then reburned by wildland fire from 1984 to 2004 within the Gila Aldo Leopold Wilderness Complex, New Mexico, USA. Thirteen fires have burned 27 000 hectares across multiple vegetation types at intervals between fires ranging from 3 yr to 14 yr. Burn severity of reburned areas showed...

Fire effects on the mobilization and uptake of nitrogen by cheatgrass (Bromus tectorum L.)

Treesearch

Brittany G. Johnson; Dale W. Johnson; Jeanne C. Chambers; Robert R. Blank

2011-01-01

Cheatgrass (Bromus tectorum L.), an invasive annual grass, is displacing native species and causing increased fire frequency in the Great Basin of the southwestern United States. Growth and nitrogen uptake patterns by cheatgrass were examined in a greenhouse study using soils from sites with the same soil type but different fire histories: 1) an area that burned in...

46 CFR 167.45-40 - Fire-fighting equipment on nautical school ships using oil as fuel.

Code of Federal Regulations, 2011 CFR

2011-10-01

... following type and character: (a) In each boiler room and in each of the machinery spaces of a nautical... approved fire extinguishers of the foam type of not less than 9.5 liters (21/2 gallons) each or 2 or more approved fire extinguishers of the carbon dioxide type of not less than 33 kilograms (15 pounds) each must...

46 CFR 167.45-40 - Fire-fighting equipment on nautical school ships using oil as fuel.

Code of Federal Regulations, 2010 CFR

2010-10-01

... following type and character: (a) In each boiler room and in each of the machinery spaces of a nautical... approved fire extinguishers of the foam type of not less than 9.5 liters (21/2 gallons) each or 2 or more approved fire extinguishers of the carbon dioxide type of not less than 33 kilograms (15 pounds) each must...

Remote sensing information for fire management and fire effects assessment

NASA Astrophysics Data System (ADS)

Chuvieco, Emilio; Kasischke, Eric S.

2007-03-01

Over the past decade, much research has been carried out on the utilization of advanced geospatial technologies (remote sensing and geographic information systems) in the fire science and fire management disciplines. Recent advances in these technologies were the focus of a workshop sponsored by the EARSEL special interest group (SIG) on forest fires (FF-SIG) and the Global Observation of Forest and Land Cover Dynamics (GOFC-GOLD) fire implementation team. Here we summarize the framework and the key findings of papers submitted from this meeting and presented in this special section. These papers focus on the latest advances for near real-time monitoring of active fires, prediction of fire hazards and danger, monitoring of fuel moisture, mapping of fuel types, and postfire assessment of the impacts from fires.

Complex systems approach to fire dynamics and climate change impacts

NASA Astrophysics Data System (ADS)

Pueyo, S.

2012-04-01

I present some recent advances in complex systems theory as a contribution to understanding fire regimes and forecasting their response to a changing climate, qualitatively and quantitatively. In many regions of the world, fire sizes have been found to follow, approximately, a power-law frequency distribution. As noted by several authors, this distribution also arises in the "forest fire" model used by physicists to study mechanisms that give rise to scale invariance (the power law is a scale-invariant distribution). However, this model does not give and does not pretend to give a realistic description of fire dynamics. For example, it gives no role to weather and climate. Pueyo (2007) developed a variant of the "forest fire" model that is also simple but attempts to be more realistic. It also results into a power law, but the parameters of this distribution change through time as a function of weather and climate. Pueyo (2007) observed similar patterns of response to weather in data from boreal forest fires, and used the fitted response functions to forecast fire size distributions in a possible climate change scenario, including the upper extreme of the distribution. For some parameter values, the model in Pueyo (2007) displays a qualitatively different behavior, consisting of simple percolation. In this case, fire is virtually absent, but megafires sweep through the ecosystem a soon as environmental forcings exceed a critical threshold. Evidence gathered by Pueyo et al. (2010) suggests that this is realistic for tropical rainforests (specifically, well-conserved upland rainforests). Some climate models suggest that major tropical rainforest regions are going to become hotter and drier if climate change goes ahead unchecked, which could cause such abrupt shifts. Not all fire regimes are well described by this model. Using data from a tropical savanna region, Pueyo et al. (2010) found that the dynamics in this area do not match its assumptions, even though fire sizes are also well fitted by a power law. A possible interpretation is that the spatial structure of fire in savannas is strongly constrained by the spatial structure of their environment. Instead of resulting from ecosystem self-organization as in the model, in this case the scale invariance in fire events would be just a reflection of scale invariance in the environment in which the ecosystem lives. These results suggest at least three major types of fire dynamics: endogenous scaling, percolating, and exogenous scaling, in addition to intermediate options. The world's biomes can be classified based on the type of dynamics that is most likely to apply in each of them, and forecasts can be carried out with the tools developed for each of these types.

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

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.

Fire Distribution in Peninsular Malaysia, Sumatra and Borneo in 2015 with Special Emphasis on Peatland Fires.

PubMed

Miettinen, Jukka; Shi, Chenghua; Liew, Soo Chin

2017-10-01

In this paper, we analyze the spatio-temporal distribution of vegetation fires in Peninsular Malaysia, Sumatra, and Borneo in the severe El Niño year of 2015, concentrating on the distribution of fires between mineral soils and peatland areas, and between land cover types in peatland areas. The results reveal that 53% of all Moderate Resolution Imaging Spectroradiometer (MODIS) fire detections were recorded in peatlands that cover only 12% of the study area. However, fire occurrence in the peatland areas was highly dependent on land cover type. Pristine peat swamp forests (PSF) experienced only marginal fire activity (30 fire detections per 1000 km 2 ) compared to deforested undeveloped peatlands (831-915 fire detections per 1000 km 2 ). Our results also highlight the extreme fire vulnerability of the southern Sumatran and Bornean peatlands under strong El Niño conditions: 71% of all peatland hotspots were detected in the provinces of South Sumatra and Central Kalimantan, which contain 29% of peatlands in the study area. Degraded PSF and all deforested peatland land cover types, including managed areas, in the two provinces were severely affected, demonstrating how difficult it is to protect even managed drained agricultural areas from unwanted fires during dry periods. Our results thereby advocate rewetting and rehabilitation as the primary management option for highly fire prone degraded undeveloped peatland areas, whenever feasible, as a means to reduce fire risk during future dry episodes.

Fire Distribution in Peninsular Malaysia, Sumatra and Borneo in 2015 with Special Emphasis on Peatland Fires

NASA Astrophysics Data System (ADS)

Miettinen, Jukka; Shi, Chenghua; Liew, Soo Chin

2017-10-01

In this paper, we analyze the spatio-temporal distribution of vegetation fires in Peninsular Malaysia, Sumatra, and Borneo in the severe El Niño year of 2015, concentrating on the distribution of fires between mineral soils and peatland areas, and between land cover types in peatland areas. The results reveal that 53% of all Moderate Resolution Imaging Spectroradiometer (MODIS) fire detections were recorded in peatlands that cover only 12% of the study area. However, fire occurrence in the peatland areas was highly dependent on land cover type. Pristine peat swamp forests (PSF) experienced only marginal fire activity (30 fire detections per 1000 km2) compared to deforested undeveloped peatlands (831-915 fire detections per 1000 km2). Our results also highlight the extreme fire vulnerability of the southern Sumatran and Bornean peatlands under strong El Niño conditions: 71% of all peatland hotspots were detected in the provinces of South Sumatra and Central Kalimantan, which contain 29% of peatlands in the study area. Degraded PSF and all deforested peatland land cover types, including managed areas, in the two provinces were severely affected, demonstrating how difficult it is to protect even managed drained agricultural areas from unwanted fires during dry periods. Our results thereby advocate rewetting and rehabilitation as the primary management option for highly fire prone degraded undeveloped peatland areas, whenever feasible, as a means to reduce fire risk during future dry episodes.

Alternative characterization of forest fire regimes: incorporating spatial patterns

Treesearch

Brandon M. Collins; Jens T. Stevens; Jay D. Miller; Scott L. Stephens; Peter M. Brown; Malcolm P. North

2017-01-01

ContextThe proportion of fire area that experienced stand-replacing fire effects is an important attribute of individual fires and fire regimes in forests, and this metric has been used to group forest types into characteristic fire regimes. However, relying on proportion alone ignores important spatial characteristics...

Fire effects in northeastern forests: oak.

Treesearch

Cary Rouse

1986-01-01

Effects of fire on the oak timber type are reviewed. Many oak stands of today originated under severe fire regimes. Fire can ill or injure oak trees. Factors determining direct injury or mortality from fire include: season of year; bark characteristics; size, vigor and form of tree; fire characteristics and stocking level.

Forest fire effects on mercury deposition in the boreal forest

Treesearch

Emma L. Witt; Randall K. Kolka; Edward A. Nater; Trent R. Wickman

2009-01-01

The objective of this study was to determine how forest fire effects Hg deposition to nearby landscapes impacted by smoke plumes. Hg concentrations and deposition were hypothesized to increase in throughfall and open precipitation after fire, and canopy type was hypothesized to influence the magnitude of the increase. Conifer canopies, which are better able to scavenge...

Modelling fire frequency and area burned across phytoclimatic regions in Spain using reanalysis data and the Canadian Fire Weather Index System

NASA Astrophysics Data System (ADS)

Bedia, J.; Herrera, S.; Gutiérrez, J. M.

2013-09-01

We develop fire occurrence and burned area models in peninsular Spain, an area of high variability in climate and fuel types, for the period 1990-2008. We based the analysis on a phytoclimatic classification aiming to the stratification of the territory into homogeneous units in terms of climatic and fuel type characteristics, allowing to test model performance under different climatic and fuel conditions. We used generalized linear models (GLM) and multivariate adaptive regression splines (MARS) as modelling algorithms and temperature, relative humidity, precipitation and wind speed, taken from the ERA-Interim reanalysis, as well as the components of the Canadian Forest Fire Weather Index (FWI) System as predictors. We also computed the standardized precipitation-evapotranspiration index (SPEI) as an additional predictor for the models of burned area. We found two contrasting fire regimes in terms of area burned and number of fires: one characterized by a bimodal annual pattern, characterizing the Nemoral and Oro-boreal phytoclimatic types, and another one exhibiting an unimodal annual cycle, with the fire season concentrated in the summer months in the Mediterranean and Arid regions. The fire occurrence models attained good skill in most of the phytoclimatic zones considered, yielding in some zones notably high correlation coefficients between the observed and modelled inter-annual fire frequencies. Total area burned also exhibited a high dependence on the meteorological drivers, although their ability to reproduce the observed annual burned area time series was poor in most cases. We identified temperature and some FWI system components as the most important explanatory variables, and also SPEI in some of the burned area models, highlighting the adequacy of the FWI system for fire modelling applications and leaving the door opened to the development a more complex modelling framework based on these predictors. Furthermore, we demonstrate the potential usefulness of ERA-Interim reanalysis data for the reconstruction of historical fire-climate relationships at the scale of analysis. Fire frequency predictions may provide a preferable basis for past fire history reconstruction, long-term monitoring and the assessment of future climate impacts on fire regimes across regions, posing several advantages over burned area as response variable.

FireWorks educational program and its effectiveness

Treesearch

Jane Kapler Smith; Nancy E. McMurray

2004-01-01

FireWorks is an educational program that provides interactive, hands-on activities for studying fire behavior, fire ecology, and human influences on three fire-dependent forest types-ponderosa pine (Pinus ponderosa), interior lodgepolepine (P. contorta var.latifolia), and whitebark pine (P. albicaulis)....

Influence of reinforcement type on the mechanical behavior and fire response of hybrid composites and sandwich structures

NASA Astrophysics Data System (ADS)

Giancaspro, James William

Lightweight composites and structural sandwich panels are commonly used in marine and aerospace applications. Using carbon, glass, and a host of other high strength fiber types, a broad range of laminate composites and sandwich panels can be developed. Hybrid composites can be constructed by laminating multiple layers of varying fiber types while sandwich panels are manufactured by laminating rigid fiber facings onto a lightweight core. However, the lack of fire resistance of the polymers used for the fabrication remains a very important problem. The research presented in this dissertation deals with an inorganic matrix (Geopolymer) that can be used to manufacture laminate composites and sandwich panels that are resistant up to 1000°C. This dissertation deals with the influence of fiber type on the mechanical behavior and the fire response of hybrid composites and sandwich structures manufactured using this resin. The results are categorized into the following distinct studies. (i) High strength carbon fibers were combined with low cost E-glass fibers to obtain hybrid laminate composites that are both economical and strong. The E-glass fabrics were used as a core while the carbon fibers were placed on the tension face and on both tension and compression faces. (ii) Structural sandwich beams were developed by laminating various types of reinforcement onto the tension and compression faces of balsa wood cores. The flexural behavior of the beams was then analyzed and compared to beams reinforced with organic composite. The effect of core density was evaluated using oak beams reinforced with inorganic composite. (iii) To measure the fire response, balsa wood sandwich panels were manufactured using a thin layer of a fire-resistant paste to serve for fire protection. Seventeen sandwich panels were fabricated and tested to measure the heat release rates and smoke-generating characteristics. The results indicate that Geopolymer can be effectively used to fabricate both high strength composite plates and sandwich panels. A 2 mm thick coating of fireproofing on balsa wood is sufficient to satisfy FAA fire requirements.

Techniques for Estimating Emissions Factors from Forest Burning: ARCTAS and SEAC4RS Airborne Measurements Indicate which Fires Produce Ozone

NASA Technical Reports Server (NTRS)

Chatfield, Robert B.; Andreae, Meinrat O.

2016-01-01

Previous studies of emission factors from biomass burning are prone to large errors since they ignore the interplay of mixing and varying pre-fire background CO2 levels. Such complications severely affected our studies of 446 forest fire plume samples measured in the Western US by the science teams of NASA's SEAC4RS and ARCTAS airborne missions. Consequently we propose a Mixed Effects Regression Emission Technique (MERET) to check techniques like the Normalized Emission Ratio Method (NERM), where use of sequential observations cannot disentangle emissions and mixing. We also evaluate a simpler "consensus" technique. All techniques relate emissions to fuel burned using C(burn) = delta C(tot) added to the fire plume, where C(tot) approximately equals (CO2 = CO). Mixed-effects regression can estimate pre-fire background values of C(tot) (indexed by observation j) simultaneously with emissions factors indexed by individual species i, delta, epsilon lambda tau alpha-x(sub I)/C(sub burn))I,j. MERET and "consensus" require more than emissions indicators. Our studies excluded samples where exogenous CO or CH4 might have been fed into a fire plume, mimicking emission. We sought to let the data on 13 gases and particulate properties suggest clusters of variables and plume types, using non-negative matrix factorization (NMF). While samples were mixtures, the NMF unmixing suggested purer burn types. Particulate properties (b scant, b abs, SSA, AAE) and gas-phase emissions were interrelated. Finally, we sought a simple categorization useful for modeling ozone production in plumes. Two kinds of fires produced high ozone: those with large fuel nitrogen as evidenced by remnant CH3CN in the plumes, and also those from very intense large burns. Fire types with optimal ratios of delta-NOy/delta- HCHO associate with the highest additional ozone per unit Cburn, Perhaps these plumes exhibit limited NOx binding to reactive organics. Perhaps these plumes exhibit limited NOx binding to reactive organics

Techniques for Estimating Emissions Factors from Forest Burning: ARCTAS and SEAC4RS Airborne Measurements Indicate Which Fires Produce Ozone

NASA Technical Reports Server (NTRS)

Chatfield, Robert B.; Andreae, Meinrat O.

2015-01-01

Previous studies of emission factors from biomass burning are prone to large errors since they ignore the interplay of mixing and varying pre-fire background CO2 levels. Such complications severely affected our studies of 446 forest fire plume samples measured in the Western US by the science teams of NASA's SEAC4RS and ARCTAS airborne missions. Consequently we propose a Mixed Effects Regression Emission Technique (MERET) to check techniques like the Normalized Emission Ratio Method (NERM), where use of sequential observations cannot disentangle emissions and mixing. We also evaluate a simpler "consensus" technique. All techniques relate emissions to fuel burned using C(sub burn) = delta C(sub tot) added to the fire plume, where C(sub tot) approximately equals (CO2 + CO). Mixed-effects regression can estimate pre-fire background values of Ctot (indexed by observation j) simultaneously with emissions factors indexed by individual species i, delta epsilon lambda tau alpha-x(sub i)/(C(sub burn))i,j., MERET and "consensus" require more than two emissions indicators. Our studies excluded samples where exogenous CO or CH4 might have been fed into a fire plume, mimicking emission. We sought to let the data on 13 gases and particulate properties suggest clusters of variables and plume types, using non-negative matrix factorization (NMF). While samples were mixtures, the NMF unmixing suggested purer burn types. Particulate properties (bscat, babs, SSA, AAE) and gas-phase emissions were interrelated. Finally, we sought a simple categorization useful for modeling ozone production in plumes. Two kinds of fires produced high ozone: those with large fuel nitrogen as evidenced by remnant CH3CN in the plumes, and also those from very intense large burns. Fire types with optimal ratios of delta-NOy/delta- HCHO associate with the highest additional ozone per unit Cburn, Perhaps these plumes exhibit limited NOx binding to reactive organics. Perhaps these plumes exhibit limited NOx binding to reactive organics.

Carbon stocks of trees killed by bark beetles and wildfire in the western United States

USGS Publications Warehouse

Hicke, Jeffrey A.; Meddens, Arjan J.H.; Allen, Craig D.; Kolden, Crystal A.

2013-01-01

Forests are major components of the carbon cycle, and disturbances are important influences of forest carbon. Our objective was to contribute to the understanding of forest carbon cycling by quantifying the amount of carbon in trees killed by two disturbance types, fires and bark beetles, in the western United States in recent decades. We combined existing spatial data sets of forest biomass, burn severity, and beetle-caused tree mortality to estimate the amount of aboveground and belowground carbon in killed trees across the region. We found that during 1984-2010, fires killed trees that contained 5-11 Tg C year-1 and during 1997-2010, beetles killed trees that contained 2-24 Tg C year-1, with more trees killed since 2000 than in earlier periods. Over their periods of record, amounts of carbon in trees killed by fires and by beetle outbreaks were similar, and together these disturbances killed trees representing 9% of the total tree carbon in western forests, a similar amount to harvesting. Fires killed more trees in lower-elevation forest types such as Douglas-fir than higher-elevation forest types, whereas bark beetle outbreaks also killed trees in higher-elevation forest types such as lodgepole pine and Engelmann spruce. Over 15% of the carbon in lodgepole pine and spruce/fir forest types was in trees killed by beetle outbreaks; other forest types had 5-10% of the carbon in killed trees. Our results document the importance of these natural disturbances in the carbon budget of the western United States.

Calibrating a forest landscape model to simulate frequent fire in Mediterranean-type shrublands

USGS Publications Warehouse

Syphard, A.D.; Yang, J.; Franklin, J.; He, H.S.; Keeley, J.E.

2007-01-01

In Mediterranean-type ecosystems (MTEs), fire disturbance influences the distribution of most plant communities, and altered fire regimes may be more important than climate factors in shaping future MTE vegetation dynamics. Models that simulate the high-frequency fire and post-fire response strategies characteristic of these regions will be important tools for evaluating potential landscape change scenarios. However, few existing models have been designed to simulate these properties over long time frames and broad spatial scales. We refined a landscape disturbance and succession (LANDIS) model to operate on an annual time step and to simulate altered fire regimes in a southern California Mediterranean landscape. After developing a comprehensive set of spatial and non-spatial variables and parameters, we calibrated the model to simulate very high fire frequencies and evaluated the simulations under several parameter scenarios representing hypotheses about system dynamics. The goal was to ensure that observed model behavior would simulate the specified fire regime parameters, and that the predictions were reasonable based on current understanding of community dynamics in the region. After calibration, the two dominant plant functional types responded realistically to different fire regime scenarios. Therefore, this model offers a new alternative for simulating altered fire regimes in MTE landscapes. ?? 2007 Elsevier Ltd. All rights reserved.

Mapping burned areas and burn severity patterns across the Mediterranean region

NASA Astrophysics Data System (ADS)

Kalogeropoulos, Christos; Amatulli, Giuseppe; Kempeneers, Pieter; Sedano, Fernando; San Miguel-Ayanz, Jesus; Camia, Andrea

2010-05-01

The Mediterranean region is highly susceptible to wildfires. On average, about 60,000 fires take place in this region every year, burning on average half a million hectares of forests and natural vegetation. Wildfires cause environmental degradation and affect the lives of thousands of people in the region. In order to minimize the consequences of these catastrophic events, fire managers and national authorities need to have in their disposal accurate and updated spatial information concerning the size of the burned area as well as the burn severity patterns. Mapping burned areas and burn severity patterns is necessary to effectively support the decision-making process in what concerns strategic (long-term) planning with the definition of post-fire actions at European and national scales. Although a comprehensive archive of burnt areas exists at the European Forest Fire Information System, the analysis of the severity of the areas affected by forest fires in the region is not yet available. Fire severity is influenced by many variables, including fuel type, topography and meteorological conditions before and during the fire. The analysis of fire severity is essential to determine the socio-economic impact of forest fires, to assess fire impacts, and to determine the need of post-fire rehabilitation measures. Moreover, fire severity is linked to forest fire emissions and determines the rate of recovery of the vegetation after the fire. Satellite imagery can give important insights about the conditions of the live fuel moisture content and can be used to assess changes on vegetation structure and vitality after forest fires. Fire events occurred in Greece, Portugal and Spain during the fire season of 2009 were recorded and analyzed in a GIS environment. The Normalized Difference Vegetation Index (NDVI), the Enhanced Vegetation Index (EVI) and the Normalized Burn Ratio (NBR) were calculated from 8-days composites MODIS/TERRA imagery from March to October 2009. In addition, subtracting a post-fire from a pre-fire image derived index produces a measure of absolute change of the vegetation condition, like the differenced Normalized Burn Ratio index (dNBR). The aim of this study was the assessment of fire severity across diverse ecological and environmental conditions in the Mediterranean region. The specific objectives were: • The analysis of the correlation between the fire severity and local site conditions, including topography, fuel type, land use, land cover. • The analysis of the correlation between fire severity and fire danger conditions during the fire, as estimated by the European Forest Fire Information System. • Assessing the performance of several vegetation indices derived from MODIS imagery in estimating fire severity. • Assessing the permanence of the burnt signal for large fires as an estimate of fire severity.

The 1977 tundra fire in the Kokolik River area of Alaska

NASA Technical Reports Server (NTRS)

1981-01-01

Presumably caused by lightning, a large fire occurred due east of Point Lay several kilometers southwest of the Kokolik River, the farthest north a fire was ever fought by Bureau of Land Management personnel in Alaska. The progress and area extent of the fire were determined by analysis of LANDSAT MSS band 5 and 7 imagery. Low altitude observations from helicopter showed the fire burned a range of vegetation and relief types which included low polygonized and upland tussock tundras. The burned area appeared wetter on the surface than the unburned area, due to a lack of moisture absorbing organic matter and the possible release of moisture from the deeper thawed zone. Suggestions for future investigations of the effects of fire on tundra and permafrost terrains are discussed.

Fire severity and ecosytem responses following crown fires in California shrublands

USGS Publications Warehouse

Keeley, J.E.; Brennan, T.; Pfaff, A.H.

2008-01-01

Chaparral shrublands burn in large high-intensity crown fires. Managers interested in how these wildfires affect ecosystem processes generally rely on surrogate measures of fire intensity known as fire severity metrics. In shrublands burned in the autumn of 2003, a study of 250 sites investigated factors determining fire severity and ecosystem responses.Using structural equation modeling we show that stand age, prefire shrub density, and the shortest interval of the prior fire history had significant direct effects on fire severity, explaining >50% of the variation in severity.Fire severity per se is of interest to resource managers primarily because it is presumed to be an indicator of important ecosystem processes such as vegetative regeneration, community recovery, and erosion. Fire severity contributed relatively little to explaining patterns of regeneration after fire. Two generalizations can be drawn: fire severity effects are mostly short-lived, i.e., by the second year they are greatly diminished, and fire severity may have opposite effects on different functional types.Species richness exhibited a negative relationship to fire severity in the first year, but fire severity impacts were substantially less in the second postfire year and varied by functional type. Much of this relationship was due to alien plants that are sensitive to high fire severity; at all scales from 1 to 1000 m2, the percentage of alien species in the postfire flora declined with increased fire severity. Other aspects of disturbance history are also important determinants of alien cover and richness as both increased with the number of times the site had burned and decreased with time since last fire.A substantial number of studies have shown that remote-sensing indices are correlated with field measurements of fire severity. Across our sites, absolute differenced normalized burn ratio (dNBR) was strongly correlated with field measures of fire severity and with fire history at a site but relative dNBR was not. Despite being correlated with fire severity, absolute dNBR showed little or no relationship with important ecosystem responses to wildfire such as shrub resprouting or total vegetative regeneration. These findings point to a critical need for further research on interpreting remote sensing indices as applied to postfire management of these shrublands.

Fire severity and ecosytem responses following crown fires in California shrublands.

PubMed

Keeley, Jon E; Brennan, Teresa; Pfaff, Anne H

2008-09-01

Chaparral shrublands burn in large high-intensity crown fires. Managers interested in how these wildfires affect ecosystem processes generally rely on surrogate measures of fire intensity known as fire severity metrics. In shrublands burned in the autumn of 2003, a study of 250 sites investigated factors determining fire severity and ecosystem responses. Using structural equation modeling we show that stand age, prefire shrub density, and the shortest interval of the prior fire history had significant direct effects on fire severity, explaining > 50% of the variation in severity. Fire severity per se is of interest to resource managers primarily because it is presumed to be an indicator of important ecosystem processes such as vegetative regeneration, community recovery, and erosion. Fire severity contributed relatively little to explaining patterns of regeneration after fire. Two generalizations can be drawn: fire severity effects are mostly shortlived, i.e., by the second year they are greatly diminished, and fire severity may have opposite effects on different functional types. Species richness exhibited a negative relationship to fire severity in the first year, but fire severity impacts were substantially less in the second postfire year and varied by functional type. Much of this relationship was due to alien plants that are sensitive to high fire severity; at all scales from 1 to 1000 m2, the percentage of alien species in the postfire flora declined with increased fire severity. Other aspects of disturbance history are also important determinants of alien cover and richness as both increased with the number of times the site had burned and decreased with time since last fire. A substantial number of studies have shown that remote-sensing indices are correlated with field measurements of fire severity. Across our sites, absolute differenced normalized burn ratio (dNBR) was strongly correlated with field measures of fire severity and with fire history at a site but relative dNBR was not. Despite being correlated with fire severity, absolute dNBR showed little or no relationship with important ecosystem responses to wildfire such as shrub resprouting or total vegetative regeneration. These findings point to a critical need for further research on interpreting remote sensing indices as applied to postfire management of these shrublands.

‘Natural background’ soil water repellency in conifer forests of the north-western USA: Its prediction and relationship to wildfire occurrence

NASA Astrophysics Data System (ADS)

Doerr, S. H.; Woods, S. W.; Martin, D. A.; Casimiro, M.

2009-06-01

SummarySoils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites ( n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by collecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were further analyzed for repellency using WDPT and contact angle ( θsl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species ( Pinus ponderosa, Pinus contorta, Picea engelmanii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long-unburnt conifer forest soils of the north-western USA is therefore incorrect. It follows that, where pre-fire water repellency levels are not known or highly variable, post-fire soil water repellency conditions are an unreliable indicator in classifying soil burn severity. The terrain and soil variables examined showed, overall, no convincing relationship with the repellency levels observed ( R2 < 0.15) except that repellency was limited in soils (i) developed over meta-sedimentary lithology and (ii) with clay contents >4%. This suggests that water repellency levels cannot be predicted with confidence from common terrain or soil variables.

'Natural background' soil water repellency in conifer forests of the north-western USA: Its prediction and relationship to wildfire occurrence

USGS Publications Warehouse

Doerr, S.H.; Woods, S.W.; Martin, D.A.; Casimiro, M.

2009-01-01

Soils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites (n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by collecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were further analyzed for repellency using WDPT and contact angle (??sl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species (Pinus ponderosa, Pinus contorta, Picea engelmanii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long-unburnt conifer forest soils of the north-western USA is therefore incorrect. It follows that, where pre-fire water repellency levels are not known or highly variable, post-fire soil water repellency conditions are an unreliable indicator in classifying soil burn severity. The terrain and soil variables examined showed, overall, no convincing relationship with the repellency levels observed (R2 < 0.15) except that repellency was limited in soils (i) developed over meta-sedimentary lithology and (ii) with clay contents >4%. This suggests that water repellency levels cannot be predicted with confidence from common terrain or soil variables. ?? 2009 Elsevier B.V.

Susceptibility of eastern U.S. habitats to invasion of Celastrus orbiculatus (oriental bittersweet) following fire

USGS Publications Warehouse

Leicht-Young, Stacey A.; Pavlovic, Noel B.; Grundel, Ralph

2013-01-01

Fire effects on invasive species are an important land management issue in areas subjected to prescribed fires as well as wildfires. These effects on invasive species can be manifested across life stages. The liana Celastrus orbiculatus (oriental bittersweet) is a widespread invader of eastern US habitats including those where fire management is in practice. This study examined if prescribed fire makes these habitats more susceptible to invasion of C. orbiculatus by seed at Indiana Dunes National Lakeshore. Four treatments (control, litter removed, high and low intensity fire) were applied in six habitat types (sand savanna/woodland, sand prairie, moraine prairie, sand oak forest, beech-maple forest, and oak-hickory forest) and germinating seedlings were tracked over two growing seasons. Treatment did not have a significant effect on the germination, survival, or biomass of C. orbiculatus. However, habitat type did influence these responses mostly in the first growing season. Moraine prairie, beech-maple forest, and oak-hickory forests had the greatest peak percentage of germinants. Moraine prairie had significantly greater survival than oak forest and savanna habitats. Control plots with intact litter, and the moraine prairie habitat had the tallest seedlings at germination, while tallest final heights and greatest aboveground biomass were highest in oak forest. Thus, fire and litter removal did not increase the susceptibility of these habitats to germination and survival of C. orbiculatus. These results indicate that most eastern US habitats are vulnerable to invasion by this species via seed regardless of the level or type of disturbance to the litter layer.

Fire and climate suitability for woody vegetation communities in the south central United States

USGS Publications Warehouse

Stroh, Esther; Struckhoff, Matthew; Stambaugh, Michael C.; Guyette, Richard P.

2018-01-01

using a physical chemistry fire frequency model. We then used the fire probability data with additional climate parameters to construct maximum entropy environmental suitability models for three south central US vegetation communities. The modeled communities included an oak type (dominated by post oak, Quercus stellata Wangenh., and blackjack oak, Q. marilandica Münchh.), a mesquite type (dominated by honey mesquite, Prosopis glandulosa Torr., and velvet mesquite, P. velutina Wooton), and a pinyon−juniper type (dominated by pinyon pine, Pinus edulis Engelm., and Utah juniper, Juniperus osteosperma [Torr.] Little). We mapped baseline and future mean fire-climate suitability using data from three global climate models for 2040 to 2069 and 2070 to 2099; we also mapped future locations of threshold conditions for which all three models agreed on suitability for each community. Future projections included northward, southward, and eastward shifts in suitable conditions for the oaks along a broad path of fire-climate stability; an overall reduction in suitable area for historic mesquite communities coupled with potential expansion to new areas; and constriction and isolation of suitable conditions for pinyon−juniper communities. The inclusion of fire probability adds an important driver of vegetation distribution to climate envelope modeling. The simple models showed good fit, but future projections failed to account for future management activities or land use changes. Results provided information on potential future de-coupling and spatial re-arrangement of environmental conditions under which these communities have historically persisted and been managed. In particular, consensus threshold maps can inform long-term planning for maintenance or restoration of these communities, and they can be used as a potential tool for other communities in fire-prone environments within the study area and beyond its borders.

ALLTEM Multi-Axis Electromagnetic Induction System Demonstration and Validation

DTIC Science & Technology

2011-11-17

fencing that test the capabilities of the platform systems Recently the Open Field area was reconfigured to emulate typical impact area conditions. The...surveyed. • Open field (indirect fire) The indirect fire subarea contains only three munition types that could be typically found at an impact area...direct fire subarea contains only three munition types that could be typically found at an impact area of a direct fire weapons range. These are 25 mm

46 CFR 161.002-2 - Types of fire-protective systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., but not be limited to, automatic fire and smoke detecting systems, manual fire alarm systems, sample... unit, fire detectors, smoke detectors, and audible and visual alarms distinct in both respects from the alarms of any other system not indicating fire. (c) Manual fire alarm systems. For the purpose of this...

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 vegetation period and lasted until November with DN concentrations in June being 4 times higher compared to the control (82 vs. 18 mg DN/L) and being negatively correlated with pH-values (r=-0.51 p<0.001). Annual DN fluxes from fire manipulated forest plots were two times higher compared to control ones (62 vs. 29 kg DN/(ha*a)) whereas only low impact was found at the pasture with 45 and 38 kg DN/(ha*a) for fire-manipulated plots and control, respectively. In general, the results exhibit highly differing response patterns of elements to fire between the two land-use types and with season. Starting in spring higher DN fluxes following fire event at the forest site could be associated with accelerated activity of soil microbes mineralizing released organic substances from burned forest floor and/or from dead roots. This mineralization process resulted in a significant increase in acidity of the soil solution that may affect important ecosystem functions like nutrient cycling and primary production. Hence, high resolution monitoring following a low intensive fire indicated nutrient losses from the forest ecosystem that could be a hazard for managed forests on nutrient poor soils if fire frequency increases with climate change.

75 FR 47824 - Agency Information Collection Activities: Submission for OMB Review; Comment Request, OMB No...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-09

...; U.S. Fire Administration's National Fire Academy Evaluation Collection AGENCY: Federal Emergency... Information Title: U.S. Fire Administration's National Fire Academy Evaluation Collection. Type of Information...

Forestry timber typing. Tanana demonstration project, Alaska ASVT. [Alaska

NASA Technical Reports Server (NTRS)

Morrissey, L. A.; Ambrosia, V. G.

1982-01-01

The feasibility of using LANDSAT digital data in conjunction with topographic data to delineate commercial forests by stand size and crown closure in the Tanana River basin of Alaska was tested. A modified clustering approach using two LANDSAT dates to generate an initial forest type classification was then refined with topographic data. To further demonstrate the ability of remotely sensed data in a fire protection planning framework, the timber type data were subsequently integrated with terrain information to generate a fire hazard map of the study area. This map provides valuable assistance in initial attack planning, determining equipment accessibility, and fire growth modeling. The resulting data sets were incorporated into the Alaska Department of Natural Resources geographic information system for subsequent utilization.

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.

Fire ecology of forests and woodlands in Utah

Treesearch

Anne F. Bradley; Nonan V. Noste; William C. Fischer

1992-01-01

Provides information on fire as an ecological factor in forest habitat types, and in pinyon-juniper woodland and oak-maple brushland communities occurring in Utah. Identifies Fire Groups based on fire's role in forest succession. Describes forest fuels and suggests considerations for fire management.

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.

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...

Evaluation of a Dynamic Load Transfer Function Using Grassland Curing Data

Treesearch

Patricia L. Andrews; Stuart A.J. Anderson; Wendy R. Anderson

2006-01-01

Understanding and calculating fire behaviour in various fuel types is essential for effective fire management, including wildfire suppression and fuels management. Fire spread in grassland fuel is affected by the curing level, the amount of dead fuel expressed as a percentage of the total (live and dead fuel combined). The influence of live fuel is included in various...

Fire containment in wood construction doesn’t just happen

Treesearch

Robert H. White; Kuma Sumathipala

2007-01-01

Regardless of the type of construction, structures capable of containing a fully developed fire do not just happen. Fire walls or area separation walls play an important role in the building codes in that they allow each portion of a building separated by such walls to be treated as a separate building. Attention to construction details is critical to maximizing the...

Ecological effects of the Hayman Fire - Part 1: Historical (pre-1860) and current (1860-2002) fire regimes

Treesearch

William H. Romme; Thomas T. Veblen; Merrill R. Kaufmann; Rosemary Sherriff; Claudia M. Regan

2003-01-01

To address historical and current fire regimes in the Hayman landscape, we first present the concepts of “historical range of variability” and ”fire regime” to provide the necessary conceptual tools for evaluating fire occurrence, fire behavior, and fire effects. Next we summarize historical (pre-1860) fire frequency and fire effects for the major forest types of the...

Bricks in historical buildings of Toledo City: characterisation and restoration

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

Lopez-Arce, Paula; Garcia-Guinea, Javier; Gracia, Mercedes

2003-01-15

Two different types of ancient bricks (12th to 14th centuries) collected from historical buildings of Toledo (Spain) were characterised by optical microscopy, scanning electron microscopy/energy-dispersive X-ray spectrometers (SEM/EDS), electron probe microanalysis (EM), X-ray diffraction (XRD), differential thermal analysis (DTA) and {sup 57}Fe-Moessbauer spectroscopy. Physical properties such as water absorption and suction, porosity, density and compression strength were also determined. Several minerals found in the brick matrix, such as garnet, let us infer raw material sources; calcite, dolomite, illite and neoformed gehlenite and diopside phases, on temperature reached in firing; secondary calcite, on first cooling scenarios; and manganese micronodules, on latemore » pollution environments. XRD and DTA of original and refired samples supply information about firing temperatures. Additional data on firing conditions and type of the original clay are provided by the Moessbauer study. Physical properties of both types of bricks were compared and correlated with raw materials and fabric and firing technology employed. The physicochemical characterisation of these bricks provides valuable data for restoration purposes to formulate new specific bricks using neighbouring raw materials.« less

30 CFR 75.1107-6 - Capacity of fire suppression devices; location and direction of nozzles.

Code of Federal Regulations, 2013 CFR

2013-07-01

... withstand rough usage and vibration when installed on mining equipment. (b) The extinguishant-discharge..., or combination type. Where fire control is achieved by internal injection, or combination of internal...

30 CFR 75.1107-6 - Capacity of fire suppression devices; location and direction of nozzles.

Code of Federal Regulations, 2012 CFR

2012-07-01

... withstand rough usage and vibration when installed on mining equipment. (b) The extinguishant-discharge..., or combination type. Where fire control is achieved by internal injection, or combination of internal...

30 CFR 75.1107-6 - Capacity of fire suppression devices; location and direction of nozzles.

Code of Federal Regulations, 2011 CFR

2011-07-01

... withstand rough usage and vibration when installed on mining equipment. (b) The extinguishant-discharge..., or combination type. Where fire control is achieved by internal injection, or combination of internal...

30 CFR 75.1107-6 - Capacity of fire suppression devices; location and direction of nozzles.

Code of Federal Regulations, 2014 CFR

2014-07-01

... withstand rough usage and vibration when installed on mining equipment. (b) The extinguishant-discharge..., or combination type. Where fire control is achieved by internal injection, or combination of internal...

ERTS-1 imagery and high flight photographs as aids to fire hazard appraisal at the NASA San Pablo Reservoir test site

NASA Technical Reports Server (NTRS)

Colwell, R. N.

1973-01-01

The identification of fire hazards at the San Pablo Reservoir Test Site in California using ERTS-1 data is discussed. It is stated that the two primary fire hazards in the area are caused by wild oat plants and eucalyptus trees. The types of imagery used in conducting the study are reported. Aerial photographs of specific areas are included to show the extent of the fire hazards.

The influence of parent material on vegetation response 15 years after the Dude Fire, Arizona

Treesearch

Jackson M. Leonard; Alvin L. Medina; Daniel G. Neary; Aregai Tecle

2015-01-01

This study examined the effects of two types of parent material, sandstone and limestone, on the response of vegetation growth after the 1990 Dude Fire in central Arizona. The operating hypothesis of the study was that, given the right conditions, severe wildfire can trigger vegetation type conversion. Overall, three patterns emerged: (1) oak density increased by 413%...

Development, installation, and testing services for an automatic, point type thermal sensor, fire protection system on a mining dozer. Final report

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

Lease, W.D.

1976-08-01

Lease AFEX, Inc., modified its standard design of an automatic fire protection system used in the past on logging equipment, and long-term, in-mine tested system on a Fiat-Alli's HD-41B dozer at the Lemmons and Company coal mine, Boonville, Ind. The modification of the standard AFEX system involved improving the actuation device. The AFEX system is called a point-type thermal sensor, automatic fire protection system. The in-mine test took place in late 1975, and early 1976. The system was then tested by simulating a fire on the dozer. The system operated successfully after the 4 months of in-mine endurance testing. (Colormore » illustrations reproduced in black and white.)« less

A scheme for the classification of explosions in the chemical process industry.

PubMed

Abbasi, Tasneem; Pasman, H J; Abbasi, S A

2010-02-15

All process industry accidents fall under three broad categories-fire, explosion, and toxic release. Of these fire is the most common, followed by explosions. Within these broad categories occur a large number of sub-categories, each depicting a specific sub-type of a fire/explosion/toxic release. But whereas clear and self-consistent sub-classifications exist for fires and toxic releases, the situation is not as clear vis a vis explosions. In this paper the inconsistencies and/or shortcomings associated with the classification of different types of explosions, which are seen even in otherwise highly authentic and useful reference books on process safety, are reviewed. In its context a new classification is attempted which may, hopefully, provide a frame-of-reference for the future.

Above-ground biomass and structure of pristine Siberian Scots pine forests as controlled by competition and fire.

PubMed

Wirth, C; Schulze, E-D; Schulze, W; von Stünzner-Karbe, D; Ziegler, W; Miljukova, I M; Sogatchev, A; Varlagin, A B; Panvyorov, M; Grigoriev, S; Kusnetzova, W; Siry, M; Hardes, G; Zimmermann, R; Vygodskaya, N N

1999-10-01

The study presents a data set of above-ground biomass (AGB), structure, spacing and fire regime, for 24 stands of pristine Siberian Scots pine (Pinus sylvestris) forests with lichens (n = 20) or Vaccinium/mosses (n = 4) as ground cover, along four chronosequences. The stands of the "lichen" site type (LT) were stratified into three chronosequences according to stand density and fire history. Allometric equations were established from 90 sample trees for stem, coarse branch, fine branch, twig and needle biomass. The LT stands exhibited a low but sustained biomass accumulation until a stand age of 383 years. AGB reached only 6-10 kg dw  m -2 after 200 years depending on stand density and fire history compared to 20 kg dw  m -2 in the "Vaccinium" type (VT) stands. Leaf area index (LAI) in the LT stands remained at 0.5-1.5 and crown cover was 30-60%, whereas LAI reached 2.5 and crown cover was >100% in the VT stands. Although nearest-neighbour analyses suggested the existence of density-dependent mortality, fire impact turned out to have a much stronger effect on density dynamics. Fire scar dating and calculation of mean and initial fire return intervals revealed that within the LT stands differences in structure and biomass were related to the severity of fire regimes, which in turn was related to the degree of landscape fragmentation by wetlands. Self-thinning analysis was used to define the local carrying capacity for biomass. A series of undisturbed LT stands was used to characterise the upper self-thinning boundary. Stands that had experienced a moderate fire regime were positioned well below the self-thinning boundary in a distinct fire-thinning band of reduced major axis regression slope -0.26. We discuss how this downward shift resulted from alternating phases of density reduction by fire and subsequent regrowth. We conclude that biomass in Siberian Scots pine forests is strongly influenced by fire and that climate change will affect ecosystem functions predominantly via changes in fire regimes.

46 CFR 161.002-2 - Types of fire-protective systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., but not be limited to, automatic fire and smoke detecting systems, manual fire alarm systems, sample extraction smoke detection systems, watchman's supervisory systems, and combinations of these systems. (b) Automatic fire detecting systems. For the purpose of this subpart, automatic fire and smoke detecting...

46 CFR 161.002-2 - Types of fire-protective systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., but not be limited to, automatic fire and smoke detecting systems, manual fire alarm systems, sample extraction smoke detection systems, watchman's supervisory systems, and combinations of these systems. (b) Automatic fire detecting systems. For the purpose of this subpart, automatic fire and smoke detecting...

Fire and birds in maritime Pacific Northwest

Treesearch

Mark H. Huff; Nathaniel E. Seavy; John D. Alexander; C. John Ralph

2005-01-01

Resource managers face the challenge of understanding how numerous factors, including fire and fire suppression, influence habitat composition and animal communities. We summarize information on fire effects on major vegetation types and bird/fire relations within the maritime Pacific Northwest, and pose management related questions and research considerations....

Are prescribed fire and thinning dominant processes affecting snag occurrence at a landscape scale?

DOE PAGES

Zarnoch, Stanley J.; Blake, John I.; Parresol, Bernard R.

2014-11-01

Snags are standing dead trees that are an important component in the nesting habitat of birds and other species. Although snag availability is believed to limit populations in managed and non-managed forests, little data are available to evaluate the relative effect of stand conditions and management on snag occurrence. We analyzed point sample data from an intensive forest inventory within an 80,000 ha landscape for four major forest types to support the hypotheses that routine low-intensity prescribed fire would increase, and thinning would decrease, snag occurrence. We employed path analysis to define a priori causal relationships to determine the directmore » and indirect effects of site quality, age, relative stand density index and fire for all forest types and thinning effects for loblolly pine and longleaf pine. Stand age was an important direct effect for loblolly pine, mixed pine-hardwoods and hardwoods, but not for longleaf pine. Snag occurrence in loblolly pine was increased by prescribed fire and decreased by thinning which confirmed our initial hypotheses. Although fire was not important in mixed pine-hardwoods, it was for hardwoods but the relationship depended on site quality. For longleaf pine the relative stand density index was the dominant variable affecting snag occurrence, which increased as the density index decreased. Site quality, age and thinning had significant indirect effects on snag occurrence in longleaf pine through their effects on the density index. Although age is an important condition affecting snag occurrence for most forest types, path analysis revealed that fire and density management practices within certain forest types can also have major beneficial effects, particularly in stands less than 60 years old.« less

Decision making under uncertainty: Recommendations for the Wildland Fire Decision Support System (WFDSS)

Treesearch

Matthew P. Thompson

2015-01-01

The management of wildfire is a dynamic, complex, and fundamentally uncertain enterprise. Fire managers face uncertainties regarding fire weather and subsequent influence on fire behavior, the effects of fire on socioeconomic and ecological resources, and the efficacy of alternative suppression actions on fire outcomes. In these types of difficult decision environments...

Plant community patterns in unburned and burned blackbrush (Coleogyne ramosissima) shrublands in the Mojave Desert

USGS Publications Warehouse

Brooks, Matthew L.; Matchett, John R.

2003-01-01

The blackbrush vegetation type is dominated by Coleogyne ramossisima, which is thought to preclude the coexistence of many other plant species. Fire can remove blackbrush cover and possibly increase plant species richness and evenness. Fire also may increase the frequency and cover of alien annual grasses, thereby intensifying landscape flammability. We tested these predictions in unburned and burned (6-14 years postfire) blackbrush at 3 sites spanning the range of this vegetation type in the Mojave Desert. Species richness in unburned blackbrush was similar to published values for other vegetation types in western North America, but richness varied significantly among the 3 sites and 4 spatial scales (1, 10, 100, and 1000 m2). Richness values declined in order from annual forbs, woody perennials, herbaceous perennials, annual grasses, cacti, to perennial grasses. Fire reduced Coleogyne cover, thus boosting species evenness. In contrast, species richness decreased after burning, although the results varied among spatial scales. Total cover was unaffected by fire because cover of woody perennials decreased, while cover of annual forbs, annual grasses, herbaceous perennials, and perennial grasses increased. Native species richness and cover decreased, whereas alien richness and cover increased after burning, especially where the alien forb Erodium cicutarium was present. Fire had no effect on frequency and variable effects on cover of alien annual grasses. These results indicate that in blackbrush species richness can vary among sites and local spatial scales, and effects of fire can vary among plant life-forms and between natives and aliens.

Forest fire danger index based on modifying Nesterov Index, fuel, and anthropogenic activities using MODIS TERRA, AQUA and TRMM satellite datasets

NASA Astrophysics Data System (ADS)

Suresh Babu, K. V.; Roy, Arijit; Ramachandra Prasad, P.

2016-05-01

Forest fire has been regarded as one of the major causes of degradation of Himalayan forests in Uttarakhand. Forest fires occur annually in more than 50% of forests in Uttarakhand state, mostly due to anthropogenic activities and spreads due to moisture conditions and type of forest fuels. Empirical drought indices such as Keetch-Byram drought index, the Nesterov index, Modified Nesterov index, the Zhdanko index which belongs to the cumulative type and the Angstrom Index which belongs to the daily type have been used throughout the world to assess the potential fire danger. In this study, the forest fire danger index has been developed from slightly modified Nesterov index, fuel and anthropogenic activities. Datasets such as MODIS TERRA Land Surface Temperature and emissivity (MOD11A1), MODIS AQUA Atmospheric profile product (MYD07) have been used to determine the dew point temperature and land surface temperature. Precipitation coefficient has been computed from Tropical Rainfall measuring Mission (TRMM) product (3B42RT). Nesterov index has been slightly modified according to the Indian context and computed using land surface temperature, dew point temperature and precipitation coefficient. Fuel type danger index has been derived from forest type map of ISRO based on historical fire location information and disturbance danger index has been derived from disturbance map of ISRO. Finally, forest fire danger index has been developed from the above mentioned indices and MODIS Thermal anomaly product (MOD14) has been used for validating the forest fire danger index.

Lateral Hypothalamus Contains Two Types of Palatability-Related Taste Responses with Distinct Dynamics

PubMed Central

Yoshida, Takashi; Monk, Kevin J.; Katz, Donald B.

2013-01-01

The taste of foods, in particular the palatability of these tastes, exerts a powerful influence on our feeding choices. Although the lateral hypothalamus (LH) has long been known to regulate feeding behavior, taste processing in LH remains relatively understudied. Here, we examined single-unit LH responses in rats subjected to a battery of taste stimuli that differed in both chemical composition and palatability. Like neurons in cortex and amygdala, LH neurons produced a brief epoch of nonspecific responses followed by a protracted period of taste-specific firing. Unlike in cortex, however, where palatability-related information only appears 500 ms after the onset of taste-specific firing, taste specificity in LH was dominated by palatability-related firing, consistent with LH's role as a feeding center. Upon closer inspection, taste-specific LH neurons fell reliably into one of two subtypes: the first type showed a reliable affinity for palatable tastes, low spontaneous firing rates, phasic responses, and relatively narrow tuning; the second type showed strongest modulation to aversive tastes, high spontaneous firing rates, protracted responses, and broader tuning. Although neurons producing both types of responses were found within the same regions of LH, cross-correlation analyses suggest that they may participate in distinct functional networks. Our data shed light on the implementation of palatability processing both within LH and throughout the taste circuit, and may ultimately have implications for LH's role in the formation and maintenance of taste preferences and aversions. PMID:23719813

Lateral hypothalamus contains two types of palatability-related taste responses with distinct dynamics.

PubMed

Li, Jennifer X; Yoshida, Takashi; Monk, Kevin J; Katz, Donald B

2013-05-29

The taste of foods, in particular the palatability of these tastes, exerts a powerful influence on our feeding choices. Although the lateral hypothalamus (LH) has long been known to regulate feeding behavior, taste processing in LH remains relatively understudied. Here, we examined single-unit LH responses in rats subjected to a battery of taste stimuli that differed in both chemical composition and palatability. Like neurons in cortex and amygdala, LH neurons produced a brief epoch of nonspecific responses followed by a protracted period of taste-specific firing. Unlike in cortex, however, where palatability-related information only appears 500 ms after the onset of taste-specific firing, taste specificity in LH was dominated by palatability-related firing, consistent with LH's role as a feeding center. Upon closer inspection, taste-specific LH neurons fell reliably into one of two subtypes: the first type showed a reliable affinity for palatable tastes, low spontaneous firing rates, phasic responses, and relatively narrow tuning; the second type showed strongest modulation to aversive tastes, high spontaneous firing rates, protracted responses, and broader tuning. Although neurons producing both types of responses were found within the same regions of LH, cross-correlation analyses suggest that they may participate in distinct functional networks. Our data shed light on the implementation of palatability processing both within LH and throughout the taste circuit, and may ultimately have implications for LH's role in the formation and maintenance of taste preferences and aversions.

Monthly fire behavior patterns

Treesearch

Mark J. Schroeder; Craig C. Chandler

1966-01-01

From tabulated frequency distributions of fire danger indexes for a nationwide network of 89 stations, the probabilities of four types of fire behavior ranging from 'fire out' to 'critical' were calculated for each month and are shown in map form.

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.

Carbon and Aerosol Emissions from Biomass Fires in Mexico

NASA Astrophysics Data System (ADS)

Hao, W. M.; Flores Garnica, G.; Baker, S. P.; Urbanski, S. P.

2009-12-01

Biomass burning is an important source of many atmospheric greenhouse gases and photochemically reactive trace gases. There are limited data available on the spatial and temporal extent of biomass fires and associated trace gas and aerosol emissions in Mexico. Biomass burning is a unique source of these gases and aerosols, in comparison to industrial and biogenic sources, because the locations of fires vary considerably both daily and seasonally and depend on human activities and meteorological conditions. In Mexico, the fire season starts in January and about two-thirds of the fires occur in April and May. The amount of trace gases and aerosols emitted by fires spatially and temporally is a major uncertainty in quantifying the impact of fire emissions on regional atmospheric chemical composition. To quantify emissions, it is necessary to know the type of vegetation, the burned area, the amount of biomass burned, and the emission factor of each compound for each ecosystem. In this study biomass burning experiments were conducted in Mexico to measure trace gas emissions from 24 experimental fires and wildfires in semiarid, temperate, and tropical ecosystems from 2005 to 2007. A range of representative vegetation types were selected for ground-based experimental burns to characterize fire emissions from representative Mexico fuels. A third of the country was surveyed each year, beginning in the north. The fire experiments in the first year were conducted in Chihuahua, Nuevo Leon, and Tamaulipas states in pine forest, oak forest, grass, and chaparral. The second-year fire experiments were conducted on pine forest, oak forest, shrub, agricultural, grass, and herbaceous fuels in Jalisco, Puebla, and Oaxaca states in central Mexico. The third-year experiments were conducted in pine-oak forests of Chiapas, coastal grass, and low subtropical forest on the Yucatan peninsula. FASS (Fire Atmosphere Sampling System) towers were deployed for the experimental fires. Each FASS system contains 4 electro-polished stainless steel canisters to sample trace gas emissions, with a corresponding set of Teflon filters in the sampling ports to collect PM2.5 particulates. In addition, biomass burning was sampled by aircraft with canisters and real-time instruments as part of the MILAGRO field campaign. We present the emission factors of CO2, CO, CH4, C2-C4 compounds, and PM2.5 for prescribed fires of the major vegetation types in Mexico, as well as for regional wildfires in southern and central Mexico. We will also present a high-resolution vegetation map in Mexico based on the Landsat satellites and the fuel consumption models for various components and sizes of fuels.

33 CFR 183.590 - Fire test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Tests § 183.590 Fire test. (a) A piece of equipment is tested under the following conditions and procedures: (1) Fuel stop valves, “USCG Type A1” or USCG Type... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Fire test. 183.590 Section 183...

33 CFR 183.590 - Fire test.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Tests § 183.590 Fire test. (a) A piece of equipment is tested under the following conditions and procedures: (1) Fuel stop valves, “USCG Type A1” or USCG Type... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fire test. 183.590 Section 183...

33 CFR 183.590 - Fire test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Tests § 183.590 Fire test. (a) A piece of equipment is tested under the following conditions and procedures: (1) Fuel stop valves, “USCG Type A1” or USCG Type... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Fire test. 183.590 Section 183...

33 CFR 183.590 - Fire test.

Code of Federal Regulations, 2013 CFR

2013-07-01

... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Tests § 183.590 Fire test. (a) A piece of equipment is tested under the following conditions and procedures: (1) Fuel stop valves, “USCG Type A1” or USCG Type... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Fire test. 183.590 Section 183...

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, and changes in carbon storage.

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, and changes in carbon storage.

Impacts of prescribed fire on Pinus rigida Mill. in upland forests of the Atlantic Coastal Plain.

PubMed

Carlo, Nicholas J; Renninger, Heidi J; Clark, Kenneth L; Schäfer, Karina V R

2016-08-01

A comparative analysis of the impacts of prescribed fire on three upland forest stands in the Northeastern Atlantic Plain, NJ, USA, was conducted. Effects of prescribed fire on water use and gas exchange of overstory pines were estimated via sap-flux rates and photosynthetic measurements on Pinus rigida Mill. Each study site had two sap-flux plots, one experiencing prescribed fire and one control (unburned) plot for comparison before and after the fire. We found that photosynthetic capacity in terms of Rubisco-limited carboxylation rate and intrinsic water-use efficiency was unaffected, while light compensation point and dark respiration rate were significantly lower in the burned vs control plots post-fire. Furthermore, quantum yield in pines in the pine-dominated stands was less affected than pines in the mixed oak/pine stand, as there was an increase in quantum yield in the oak/pine stand post-fire compared with the control (unburned) plot. We attribute this to an effect of forest type but not fire per se. Average daily sap-flux rates of the pine trees increased compared with control (unburned) plots in pine-dominated stands and decreased in the oak/pine stand compared with control (unburned) plots, potentially due to differences in fuel consumption and pre-fire sap-flux rates. Finally, when reference canopy stomatal conductance was analyzed, pines in the pine-dominated stands were more sensitive to changes in vapor pressure deficit (VPD), while stomatal responses of pines in the oak/pine stand were less affected by VPD. Therefore, prescribed fire affects physiological functioning and water use of pines, but the effects may be modulated by forest stand type and fuel consumption pattern, which suggests that these factors may need to be taken into account for forest management in fire-dominated systems. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Previous fires moderate burn severity of subsequent wildland fires in two large western US wilderness areas

Treesearch

Sean A. Parks; Carol Miller; Cara R. Nelson; Zachary A. Holden

2014-01-01

Wildland fire is an important natural process in many ecosystems. However, fire exclusion has reduced frequency of fire and area burned in many dry forest types, which may affect vegetation structure and composition, and potential fire behavior. In forests of the western U.S., these effects pose a challenge for fire and land managers who seek to restore the ecological...

Developing models to predict the number of fire hotspots from an accumulated fuel dryness index by vegetation type and region in Mexico

Treesearch

D. Vega-Nieva; J. Briseño-Reyes; M. Nava-Miranda; E. Calleros-Flores; P. López-Serrano; J. Corral-Rivas; E. Montiel-Antuna; M. Cruz-López; M. Cuahutle; R. Ressl; E. Alvarado-Celestino; A. González-Cabán; E. Jiménez; J. Álvarez-González; A. Ruiz-González; R. Burgan; H. Preisler

2018-01-01

Understanding the linkage between accumulated fuel dryness and temporal fire occurrence risk is key for improving decision-making in forest fire management, especially under growing conditions of vegetation stress associated with climate change. This study addresses the development of models to predict the number of 10-day observed Moderate-Resolution Imaging...

An application of LANDSAT digital technology to forest fire fuel type mapping

NASA Technical Reports Server (NTRS)

Kourtz, P. H.

1977-01-01

The role of digital classifications suitable as fuel maps was examined. A Taylor enhancement was produced for an 8 million hectare fire control region showing water, muskeg, coniferous, deciduous and mixed stands, clearcut logging, burned areas, regeneration areas, nonforested areas and large forest roads. Use of the map by fire control personnel demonstrated its usefulness for initial attack decision making.

Impact of prescribed fire and other factors on cheatgrass persistence in a Sierra Nevada ponderosa pine forest

USGS Publications Warehouse

Keeley, J.E.; McGinnis, T.W.

2007-01-01

Following the reintroduction of fire Bromus tectorum has invaded the low elevation ponderosa pine forests in parts of Kings Canyon National Park, California. We used prescribed burns, other field manipulations, germination studies, and structural equation modelling, to investigate how fire and other factors affect the persistence of cheatgrass in these forests. Our studies show that altering burning season to coincide with seed maturation is not likely to control cheatgrass because sparse fuel loads generate low fire intensity. Increasing time between prescribed fires may inhibit cheatgrass by increasing surface fuels (both herbaceous and litter), which directly inhibit cheatgrass establishment, and by creating higher intensity fires capable of killing a much greater fraction of the seed bank. Using structural equation modelling, postfire cheatgrass dominance was shown to be most strongly controlled by the prefire cheatgrass seedbank; other factors include soil moisture, fire intensity, soil N, and duration of direct sunlight. Current fire management goals in western conifer forests are focused on restoring historical fire regimes; however, these frequent fire regimes may enhance alien plant invasion in some forest types. Where feasible, fire managers should consider the option of an appropriate compromise between reducing serious fire hazards and exacerbating alien plant invasions. ?? IAWF 2007.

Fire-related medical science

NASA Technical Reports Server (NTRS)

Knight, Douglas R.

1987-01-01

Spacecraft fire safety may be improved by the use of a fire-retardant atmosphere in occupied spaces. Low concentrations of oxygen can protect humans from fire damage by reducing the rate and spread of combustion, but care must be taken to avoid the hypoxic effects of oxygen-lean atmospheres. Crews can live and work in 11 percent oxygen if barometric pressure were adjusted to maintain the partial pressure of oxygen above 16 kPa. Eleven percent oxygen should prevent most types of fires, since 15 percent oxygen retards the combustion of paper and 13 percent oxygen extinguishes pentane flames. Test results indicate that seated humans can perform mental tasks in atmospheres containing 11.5 percent oxygen. Although this strategy of fire safety is under consideration for submarines, it could be adapted to spacecraft once operational procedures define a maximum hyperbaric pressure and fire research defines the effects of reduced oxygen concentrations on combustion in low gravity environments.

Field procedures for verification and adjustment of fire behavior predictions

Treesearch

Richard C. Rothermel; George C. Rinehart

1983-01-01

The problem of verifying predictions of fire behavior, primarily rate of spread, is discussed in terms of the fire situation for which predictions are made, and the type of fire where data are to be collected. Procedures for collecting data and performing analysis are presented for both readily accessible fires where data should be complete, and for inaccessible fires...

Space station internal environmental and safety concerns

NASA Technical Reports Server (NTRS)

Cole, Matthew B.

1987-01-01

Space station environmental and safety concerns, especially those involving fires, are discussed. Several types of space station modules and the particular hazards associated with each are briefly surveyed. A brief history of fire detection and suppression aboard spacecraft is given. Microgravity fire behavior, spacecraft fire detector systems, space station fire suppression equipment and procedures, and fire safety in hyperbaric chambers are discussed.

Mental arithmetic leads to multiple discrete changes from baseline in the firing patterns of human thalamic neurons.

PubMed

Kim, J H; Ohara, S; Lenz, F A

2009-04-01

Primate thalamic action potential bursts associated with low-threshold spikes (LTS) occur during waking sensory and motor activity. We now test the hypothesis that different firing and LTS burst characteristics occur during quiet wakefulness (spontaneous condition) versus mental arithmetic (counting condition). This hypothesis was tested by thalamic recordings during the surgical treatment of tremor. Across all neurons and epochs, preburst interspike intervals (ISIs) were bimodal at median values, consistent with the duration of type A and type B gamma-aminobutyric acid inhibitory postsynaptic potentials. Neuronal spike trains (117 neurons) were categorized by joint ISI distributions into those firing as LTS bursts (G, grouped), firing as single spikes (NG, nongrouped), or firing as single spikes with sporadic LTS bursting (I, intermediate). During the spontaneous condition (46 neurons) only I spike trains changed category. Overall, burst rates (BRs) were lower and firing rates (FRs) were higher during the counting versus the spontaneous condition. Spike trains in the G category sometimes changed to I and NG categories at the transition from the spontaneous to the counting condition, whereas those in the I category often changed to NG. Among spike trains that did not change category by condition, G spike trains had lower BRs during counting, whereas NG spike trains had higher FRs. BRs were significantly greater than zero for G and I categories during wakefulness (both conditions). The changes between the spontaneous and counting conditions are most pronounced for the I category, which may be a transitional firing pattern between the bursting (G) and relay modes of thalamic firing (NG).

Dopamine Neurons Change the Type of Excitability in Response to Stimuli

PubMed Central

Gutkin, Boris S.; Lapish, Christopher C.; Kuznetsov, Alexey

2016-01-01

The dynamics of neuronal excitability determine the neuron’s response to stimuli, its synchronization and resonance properties and, ultimately, the computations it performs in the brain. We investigated the dynamical mechanisms underlying the excitability type of dopamine (DA) neurons, using a conductance-based biophysical model, and its regulation by intrinsic and synaptic currents. Calibrating the model to reproduce low frequency tonic firing results in N-methyl-D-aspartate (NMDA) excitation balanced by γ-Aminobutyric acid (GABA)-mediated inhibition and leads to type I excitable behavior characterized by a continuous decrease in firing frequency in response to hyperpolarizing currents. Furthermore, we analyzed how excitability type of the DA neuron model is influenced by changes in the intrinsic current composition. A subthreshold sodium current is necessary for a continuous frequency decrease during application of a negative current, and the low-frequency “balanced” state during simultaneous activation of NMDA and GABA receptors. Blocking this current switches the neuron to type II characterized by the abrupt onset of repetitive firing. Enhancing the anomalous rectifier Ih current also switches the excitability to type II. Key characteristics of synaptic conductances that may be observed in vivo also change the type of excitability: a depolarized γ-Aminobutyric acid receptor (GABAR) reversal potential or co-activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) leads to an abrupt frequency drop to zero, which is typical for type II excitability. Coactivation of N-methyl-D-aspartate receptors (NMDARs) together with AMPARs and GABARs shifts the type I/II boundary toward more hyperpolarized GABAR reversal potentials. To better understand how altering each of the aforementioned currents leads to changes in excitability profile of DA neuron, we provide a thorough dynamical analysis. Collectively, these results imply that type I excitability in dopamine neurons might be important for low firing rates and fine-tuning basal dopamine levels, while switching excitability to type II during NMDAR and AMPAR activation may facilitate a transient increase in dopamine concentration, as type II neurons are more amenable to synchronization by mutual excitation. PMID:27930673

Changes in Carbon Emissions in Colombian Savannas Derived From Recent Land use and Land Cover Change

NASA Astrophysics Data System (ADS)

Etter, A.; Sarmiento, A.

2007-12-01

The global contribution of carbon emissions from land use dynamics and change to the global carbon (C) cycle is still uncertain, a major concern in global change modeling. Carbon emission from fires in the tropics is significant and represents 9% of the net primary production, and 50% of worldwide C emissions from fires are attributable to savanna fires. Such emissions may vary significantly due to differences in ecosystem types. Most savanna areas are devoted to grazing land uses making methane emissions also important in savanna ecosystems. Land use change driven by intensification of grazing and cropping has become a major factor affecting C emission dynamics from savanna regions. Colombia has some 17 MHa of mesic savannas which have been historically burned. Due to changes in market demands and improved accessibility during the last 20 years, important areas of savannas changed land use from predominantly extensive grazing to crops and intensive grazing systems. This research models and evaluates the impacts of such land use changes on the spatial and temporal burning patterns and C emissions in the Orinoco savannas of Colombia. We address the effects of land use change patterns using remote sensing data from MODIS and Landsat, ecosystem mapping products, and spatial GIS analysis. First we map the expansion of the agricultural frontier from the 1980s-2000s. We then model the changes in land use from the 1980s using a statistical modeling approach to analyze and quantify the impact of accessibility, ecosystem type and land tenure. We calculate the effects on C emissions from fire regimes and other sources of C based on patterns and extent of burned areas in the 2000s for different savanna ecosystem types and land uses. In the Llanos the fire regime exhibits a marked seasonal variability with most fire events occurring during the dry season between December-March. Our analysis shows that fire frequencies vary consistently between 0.6 and 2.8 fires.yr-1 per 2,500 Ha among the different savanna ecosystem types. Highest frequencies and largest burned areas occur in the less accessible well-drained savannas of the southern part of the region. The analysis also reveals a close relationship between land tenure and fire regimes, with highest frequencies in Indigenous Reserves, followed by private land ranches and National Parks, indicating that most fires are human induced. By 2000 more than 500k hectares of natural savannas were transformed to sown pastures (Brachiaria spp.), and some 100k hectares were planted with oil palm and irrigated rice. Such changes have taken place in more accessible areas and slightly better soils. In areas subject to land use change and intensification a significant reduction in fire frequency can be observed. Because such land use changes have been occurring in savanna types with better soils and higher aerial biomass values, the average effect on reduction of C-emissions is some 30 to 50% larger than the effect on fire area reduction. Our results indicate a reduction of fire frequencies greater than 80% in areas where savannas were replaced by introduced Brachiaria pastures. However the reduction in C emissions from fire reduction in these pastures is exceeded by the parallel emissions from the increase in the cattle stocking rates with a net effect of an additional emission of 0.5 Gt.CO2 equivalents. We make preliminary projections of future emission trends based on the land use change model, and we discuss the likely effects of future sources and sinks of C expected from the increase of irrigated rice crops and from projected oil palm and timber plantations.

Fire effects on temperate forest soil C and N storage.

PubMed

Nave, Lucas E; Vance, Eric D; Swanston, Christopher W; Curtis, Peter S

2011-06-01

Temperate forest soils store globally significant amounts of carbon (C) and nitrogen (N). Understanding how soil pools of these two elements change in response to disturbance and management is critical to maintaining ecosystem services such as forest productivity, greenhouse gas mitigation, and water resource protection. Fire is one of the principal disturbances acting on forest soil C and N storage and is also the subject of enormous management efforts. In the present article, we use meta-analysis to quantify fire effects on temperate forest soil C and N storage. Across a combined total of 468 soil C and N response ratios from 57 publications (concentrations and pool sizes), fire had significant overall effects on soil C (-26%) and soil N (-22%). The impacts of fire on forest floors were significantly different from its effects on mineral soils. Fires reduced forest floor C and N storage (pool sizes only) by an average of 59% and 50%, respectively, but the concentrations of these two elements did not change. Prescribed fires caused smaller reductions in forest floor C and N storage (-46% and -35%) than wildfires (-67% and -69%), and the presence of hardwoods also mitigated fire impacts. Burned forest floors recovered their C and N pools in an average of 128 and 103 years, respectively. Among mineral soils, there were no significant changes in C or N storage, but C and N concentrations declined significantly (-11% and -12%, respectively). Mineral soil C and N concentrations were significantly affected by fire type, with no change following prescribed burns, but significant reductions in response to wildfires. Geographic variation in fire effects on mineral soil C and N storage underscores the need for region-specific fire management plans, and the role of fire type in mediating C and N shifts (especially in the forest floor) indicates that averting wildfires through prescribed burning is desirable from a soils perspective.

Influence of the contractile properties of muscle on motor unit firing rates during a moderate-intensity contraction in vivo.

PubMed

Trevino, Michael A; Herda, Trent J; Fry, Andrew C; Gallagher, Philip M; Vardiman, John P; Mosier, Eric M; Miller, Jonathan D

2016-08-01

It is suggested that firing rate characteristics of motor units (MUs) are influenced by the physical properties of the muscle. However, no study has correlated MU firing rates at recruitment, targeted force, or derecruitment with the contractile properties of the muscle in vivo. Twelve participants (age = 20.67 ± 2.35 yr) performed a 40% isometric maximal voluntary contraction of the leg extensors that included linearly increasing, steady force, and decreasing segments. Muscle biopsies were collected with myosin heavy chain (MHC) content quantified, and surface electromyography (EMG) was recorded from the vastus lateralis. The EMG signal was decomposed into the firing events of single MUs. Slopes and y-intercepts were calculated for 1) firing rates at recruitment vs. recruitment threshold, 2) mean firing rates at steady force vs. recruitment threshold, and 3) firing rates at derecruitment vs. derecruitment threshold relationships for each subject. Correlations among type I %MHC isoform content and the slopes and y-intercepts from the three relationships were examined. Type I %MHC isoform content was correlated with MU firing rates at recruitment (y-intercepts: r = -0.577; slopes: r = 0.741) and targeted force (slopes: r = 0.853) vs. recruitment threshold and MU firing rates at derecruitment (y-intercept: r = -0.597; slopes: r = 0.701) vs. derecruitment threshold relationships. However, the majority of the individual MU firing rates vs. recruitment and derecruitment relationships were not significant (P > 0.05) and, thus, revealed no systematic pattern. In contrast, MU firing rates during the steady force demonstrated a systematic pattern with higher firing rates for the lower- than higher-threshold MUs and were correlated with the physical properties of MUs in vivo. Copyright © 2016 the American Physiological Society.

Packing Optimization of an Intentionally Stratified Sorbent Bed Containing Dissimilar Media Types

NASA Technical Reports Server (NTRS)

Kidd, Jessica; Guttromson, Jayleen; Holland, Nathan

2010-01-01

The Fire Cartridge is a packed bed air filter with two different and separate layers of media designed to provide respiratory protection from combustion products after a fire event on the International Space Station (ISS). The first layer of media is a carbon monoxide catalyst made from gold nanoparticles dispersed on iron oxide. The second layer of media is universal carbon, commonly used in commercial respirator filters. Each layer must be optimally packed to effectively remove contaminants from the air. Optimal packing is achieved by vibratory agitations. However, if post-packing movement of the media within the cartridge occurs, mixing of the bed layers, air voids, and channeling could cause preferential air flow and allow contaminants to pass. Several iterations of prototype fire cartridges were developed to reduce post-packing movement of the media within each layer (settling), and to prevent mixing of the two media types. Both types of movement of the media contribute to decreased fire cartridge performance. Each iteration of the fire cartridge design was tested to demonstrate mechanical loads required to cause detrimental movement within the bed, and resulting level of functionality of the media beds after movement was detected. In order to optimally pack each layer, vertical, horizontal, and orbital agitations were tested and a final packed bulk density was calculated for each method. Packed bulk density must be calculated for each lot of catalyst to accommodate variations in particle size, shape, and density. In addition, a physical divider sheet between each type of media was added within the fire cartridge design to further inhibit intermixing of the bed layers.

Fire safety

Treesearch

Robert H. White; Mark A. Dietenberger

1999-01-01

Fire safety is an important concern in all types of construction. The high level of national concern for fire safety is reflected in limitations and design requirements in building codes. These code requirements are discussed in the context of fire safety design and evaluation in the initial section of this chapter. Since basic data on fire behavior of wood products...

Evaluation of fire hazard inspection procedures in Butte County, California

Treesearch

William S. Folkman

1967-01-01

To assess effectiveness of fire hazard inspection procedures in securing compliance with fire safety requirements, effects of different types and combinations of contacts and timing were determined, and the production capacity of inspectors measured. It was demonstrated that fire law inspection is as much fire prevention education and engineering as it is law...

The Effects of Vegetative Type, Edges, Fire History, Rainfall and Management in Fire-Maintained Habitat

NASA Technical Reports Server (NTRS)

Breininger, David R.; Foster, Tammy E.; Carter, Geoffrey M.; Duncan, Brean W.; Stolen, Eric D.; Lyon, James E.

2018-01-01

The combined effects of fire history, climate, and landscape features (e.g., edges) on habitat specialists need greater focus in fire ecology studies, which usually only emphasize characteristics of the most recent fire. Florida scrub-jays are an imperiled, territorial species that prefer medium (1.2-1.7 m) shrub heights, which are dynamic because of frequent fires. We measured short, medium, and tall habitat quality states annually within 10 ha grid cells (that represented potential territories) because fires and vegetative recovery cause annual variation in habitat quality. We used multistate models and model selection to test competing hypotheses about how transition probabilities vary between states as functions of environmental covariates. Covariates included vegetative type, edges (e.g., roads, forests), precipitation, openings (gaps between shrubs), mechanical cutting, and fire characteristics. Fire characteristics not only included an annual presence/absence of fire covariate, but also fire history covariates: time since the previous fire, the longest fire-free interval, and the number of repeated fires. Statistical models with support included many covariates for each transition probability, often including fire history, interactions and nonlinear relationships. Tall territories resulted from 28 years of fire suppression and habitat fragmentation that reduced the spread of fires across landscapes. Despite 35 years of habitat restoration and prescribed fires, half the territories remained tall suggesting a regime shift to a less desirable habitat condition. Edges reduced the effectiveness of fires in setting degraded scrub and flatwoods into earlier successional states making mechanical cutting an important tool to compliment frequent prescribed fires.

Photo guide for estimating fuel loading and fire behavior in mixed-oak forests of the Mid-Atlantic Region

Treesearch

Patrick H. Brose

2009-01-01

A field guide of 45 pairs of photographs depicting ericaceous shrub, leaf litter, and logging slash fuel types of eastern oak forests and observed fire behavior of these fuel types during prescribed burning. The guide contains instructions on how to use the photo guide to choose appropriate fuel models for prescribed fire planning.

Natural 'background' soil water repellency in conifer forests: its prediction and relationship to wildfire occurrence

NASA Astrophysics Data System (ADS)

Doerr, Stefan; Woods, Scott; Martin, Deborah; Casimiro, Marta

2013-04-01

Soils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites (n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by col- lecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were fur- ther analyzed for repellency using WDPT and contact angle (hsl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species (Pinus ponderosa, Pinus contorta, Picea engelma- nii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long- unburnt conifer forest soils of the north-western USA is therefore incorrect. It follows that, where pre-fire water repellency levels are not known or highly variable, post-fire soil water repellency conditions are an unreliable indicator in classifying soil burn severity. The terrain and soil variables examined showed, overall, no convincing relationship with the repellency levels observed (R2 < 0.15) except that repellency was limited in soils (i) developed over meta-sedimen- tary lithology and (ii) with clay contents >4%. This suggests that water repellency levels cannot be pre- dicted with confidence from common terrain or soil variables. This work is presented in the memory of the late Scott Woods, who was instrumental in the success of this study and an inspiration to us all.

Technology and Organisation of Inka Pottery Production in the Leche Valley. Part II: Study of Fired Vessels

NASA Astrophysics Data System (ADS)

Hayashida, F.; Häusler, W.; Riederer, J.; Wagner, U.

2003-09-01

Ceramic finds from the Inka workshops at Tambo Real and La Viña in the Leche Valley in northern Peru were studied by Mössbauer spectroscopy, thin section microscopy and X-ray diffraction. Sherds of Inka style vessels and of local style vessels can be distinguished by their shape, although local techniques appear to have been used in making both types. A reconstruction of the firing techniques by scientific studies of the ceramic material does not reveal a substantial difference in material or in the firing of both forms, although high firing temperatures were necessary to achieve sufficient stability of the large Inka style vessels. It cannot be decided whether the smaller local vessels were fired together with the Inka vessels or separately. Most of the variation in the maximum firing temperature can be explained with the normal temperature and atmosphere fluctuations in an open pit kiln.

Remote sensing of vegetation fires and its contribution to a fire management information system

Treesearch

Stephane P. Flasse; Simon N. Trigg; Pietro N. Ceccato; Anita H. Perryman; Andrew T. Hudak; Mark W. Thompson; Bruce H. Brockett; Moussa Drame; Tim Ntabeni; Philip E. Frost; Tobias Landmann; Johan L. le Roux

2004-01-01

In the last decade, research has proven that remote sensing can provide very useful support to fire managers. This chapter provides an overview of the types of information remote sensing can provide to the fire community. First, it considers fire management information needs in the context of a fire management information system. An introduction to remote sensing then...

Multiple-Parameter, Low-False-Alarm Fire-Detection Systems

NASA Technical Reports Server (NTRS)

Hunter, Gary W.; Greensburg, Paul; McKnight, Robert; Xu, Jennifer C.; Liu, C. C.; Dutta, Prabir; Makel, Darby; Blake, D.; Sue-Antillio, Jill

2007-01-01

Fire-detection systems incorporating multiple sensors that measure multiple parameters are being developed for use in storage depots, cargo bays of ships and aircraft, and other locations not amenable to frequent, direct visual inspection. These systems are intended to improve upon conventional smoke detectors, now used in such locations, that reliably detect fires but also frequently generate false alarms: for example, conventional smoke detectors based on the blockage of light by smoke particles are also affected by dust particles and water droplets and, thus, are often susceptible to false alarms. In contrast, by utilizing multiple parameters associated with fires, i.e. not only obscuration by smoke particles but also concentrations of multiple chemical species that are commonly generated in combustion, false alarms can be significantly decreased while still detecting fires as reliably as older smoke-detector systems do. The present development includes fabrication of sensors that have, variously, micrometer- or nanometer-sized features so that such multiple sensors can be integrated into arrays that have sizes, weights, and power demands smaller than those of older macroscopic sensors. The sensors include resistors, electrochemical cells, and Schottky diodes that exhibit different sensitivities to the various airborne chemicals of interest. In a system of this type, the sensor readings are digitized and processed by advanced signal-processing hardware and software to extract such chemical indications of fires as abnormally high concentrations of CO and CO2, possibly in combination with H2 and/or hydrocarbons. The system also includes a microelectromechanical systems (MEMS)-based particle detector and classifier device to increase the reliability of measurements of chemical species and particulates. In parallel research, software for modeling the evolution of a fire within an aircraft cargo bay has been developed. The model implemented in the software can describe the concentrations of chemical species and of particulate matter as functions of time. A system of the present developmental type and a conventional fire detector were tested under both fire and false-alarm conditions in a Federal Aviation Administration cargo-compartment- testing facility. Both systems consistently detected fires. However, the conventional fire detector consistently generated false alarms, whereas the developmental system did not generate any false alarms.

Impact of forest fires on particulate matter and ozone levels during the 2003, 2004 and 2005 fire seasons in Portugal.

PubMed

Martins, V; Miranda, A I; Carvalho, A; Schaap, M; Borrego, C; Sá, E

2012-01-01

The main purpose of this work is to estimate the impact of forest fires on air pollution applying the LOTOS-EUROS air quality modeling system in Portugal for three consecutive years, 2003-2005. Forest fire emissions have been included in the modeling system through the development of a numerical module, which takes into account the most suitable parameters for Portuguese forest fire characteristics and the burnt area by large forest fires. To better evaluate the influence of forest fires on air quality the LOTOS-EUROS system has been applied with and without forest fire emissions. Hourly concentration results have been compared to measure data at several monitoring locations with better modeling quality parameters when forest fire emissions were considered. Moreover, hourly estimates, with and without fire emissions, can reach differences in the order of 20%, showing the importance and the influence of this type of emissions on air quality. Copyright © 2011 Elsevier B.V. All rights reserved.

[Factors affecting the vegetation restoration after fires in cold temperate wetlands: A review].

PubMed

Zhao, Feng-Jun; Wang, Li-Zhong; Shu, Li-Fu; Chen, Peng-Yu; Chen, Li-guang

2013-03-01

Cold temperate wetland plays an important role in maintaining regional ecological balance. Fire is an important disturbance factor in wetland ecosystem. Severe burning can induce the marked degradation of the ecological functions of wetland ecosystem. The vegetation restoration, especially the early vegetation restoration, after fires, is the premise and basis for the recovery of the ecological functions of the ecosystem. This paper reviewed the research progress on the factors affecting the vegetation restoration after fires in wetlands. The vegetation restoration after fires in cold temperate wetlands was controlled by the fire intensity, fire size, vegetation types before fires, regeneration characteristics of plant species, and site conditions. It was considered that the long-term monitoring on the post-fire vegetation restoration in cold temperate wetland, the key factors affecting the vegetation restoration, the roles of frozen soil layer on the post-fire vegetation restoration, and the theories and technologies on the vegetation restoration would be the main research directions in the future.

46 CFR 162.028-7 - Procedure for listing and labeling.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and motorboats may make application for listing and labeling as a marine-type portable fire..., AND MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Extinguishers, Fire, Portable, Marine Type § 162.028-7 Procedure for listing and labeling. (a) Manufacturers having a marine-type portable...

Bidirectional modulation of fear extinction by mediodorsal thalamic firing in mice.

PubMed

Lee, Sukchan; Ahmed, Touqeer; Lee, Soojung; Kim, Huisu; Choi, Sukwoo; Kim, Duk-Soo; Kim, Sang Jeong; Cho, Jeiwon; Shin, Hee-Sup

2011-12-25

The mediodorsal thalamic nucleus has been implicated in the control of memory processes. However, the underlying neural mechanism remains unclear. Here we provide evidence for bidirectional modulation of fear extinction by the mediodorsal thalamic nucleus. Mice with a knockout or mediodorsal thalamic nucleus-specific knockdown of phospholipase C β4 exhibited impaired fear extinction. Mutant mediodorsal thalamic nucleus neurons in slices showed enhanced burst firing accompanied by increased T-type Ca(2+) currents; blocking of T channels in vivo rescued the fear extinction. Tetrode recordings in freely moving mice revealed that, during extinction, the single-spike (tonic) frequency of mediodorsal thalamic nucleus neurons increased in wild-type mice, but was static in mutant mice. Furthermore, tonic-evoking microstimulations of the mediodorsal thalamic nucleus, contemporaneous with the extinction tones, rescued fear extinction in mutant mice and facilitated it in wild-type mice. In contrast, burst-evoking microstimulation suppressed extinction in wild-type mice, mimicking the mutation. These results suggest that the firing mode of the mediodorsal thalamic nucleus is critical for the modulation of fear extinction.

Fire dynamics and implications for nitrogen cycling in boreal forests

USGS Publications Warehouse

Harden, J.W.; Mack, M.; Veldhuis, H.; Gower, S.T.

2003-01-01

We used a dynamic, long-term mass balance approach to track cumulative carbon (C) and nitrogen (N) losses to fire in boreal Manitoba over the 6500 years since deglaciation. Estimated C losses to decomposition and fire, combined with measurements of N pools in mature and burned forest floors, suggest that loss of N by combustion has likely resulted in a long-term loss that exceeds the amount of N stored in soil today by 2 to 3 times. These estimates imply that biological N fixation rates could be as high as 5 to 10 times atmospheric deposition rates in boreal regions. At the site scale, the amount of N lost is due to N content of fuels, which varies by stand type and fire severity, which in turn vary with climate and fire dynamics. The interplay of fire frequency, fire severity, and N partitioning during regrowth are important for understanding rates and sustainability of nutrient and carbon cycling over millenia and over broad regions.

Revised (Mixed-Effects) Estimation for Forest Burning Emissions of Gases and Smoke, Fire/Emission Factor Typologies, and Potential Remote Sensing Classification of Types for Use in Ozone and Absorbing-Carbon Simulation

NASA Astrophysics Data System (ADS)

Chatfield, R. B.; Segal-Rosenhaimer, M.

2014-12-01

We summarize recent progress (a) in correcting biomass burning emissions factors deduced from airborne sampling of forest fire plumes, (b) in understanding the variability in reactivity of the fresh plumes sampled in ARCTAS (2008), DC3 (2012), and SEAC4RS (2013) airborne missions, and (c) in a consequent search for remotely sensed quantities that help classify forest-fire plumes. Particle properties, chemical speciation, and smoke radiative properties are related and mutually informative, as pictures below suggest (slopes of lines of same color are similar). (a) Mixed-effects (random-effects) statistical modeling provides estimates of both emission factors and a reasonable description of carbon-burned simultaneously. Different fire plumes will have very different contributions to volatile organic carbon reactivity; this may help explain differences of free NOx(both gas- and particle-phase), and also of ozone production, that have been noted for forest-fire plumes in California. Our evalualations check or correct emission factors based on sequential measurements (e.g., the Normalized Ratio Enhancement and similar methods). We stress the dangers of methods relying on emission-ratios to CO. (b) This work confirms and extends many reports of great situational variability in emissions factors. VOCs vary in OH reactivity and NOx-binding. Reasons for variability are not only fuel composition, fuel condition, etc, but are confused somewhat by rapid transformation and mixing of emissions. We use "unmixing" (distinct from mixed-effects) statistics and compare briefly to approaches like neural nets. We focus on one particularly intense fire the notorious Yosemite Rim Fire of 2013. In some samples, NOx activity was not so surpressed by binding into nitrates as in other fires. While our fire-typing is evolving and subject to debate, the carbon-burned Δ(CO2+CO) estimates that arise from mixed effects models, free of confusion by background-CO2 variation, should provide a solid base for discussion. (c) We report progress using promising links we find between emissions-related "fire types" and promising features deducible from remote observations of plumes, e.g., single scatter albedo, Ångström exponent of scattering, Ångström exponent of absorption, (CO column density)/(aerosol optical depth).

Unprecedented remote sensing data over King and Rim megafires in the Sierra Nevada Mountains of California.

PubMed

Stavros, E Natasha; Tane, Zachary; Kane, Van R; Veraverbeke, Sander; McGaughey, Robert J; Lutz, James A; Ramirez, Carlos; Schimel, David

2016-11-01

Megafires have lasting social, ecological, and economic impacts and are increasing in the western contiguous United States. Because of their infrequent nature, there is a limited sample of megafires to investigate their unique behavior, drivers, and relationship to forest management practices. One approach is to characterize critical information pre-, during, and post-fire using remote sensing. In August 2013, the Rim Fire burned 104,131 ha and in September 2014, the King Fire burned 39,545 ha. Both fires occurred in California's Sierra Nevada. The areas burned by these fires were fortuitously surveyed by airborne campaigns, which provided the most recent remote sensing technologies not currently available from satellite. Technologies include an imaging spectrometer spanning the visible to shortwave infrared (0.38-2.5 μm), a multispectral, high-spatial resolution thermal infrared (3.5-13 μm) spectroradiometer, and Light Detection and Ranging that provide spatial resolutions of pixels from 1 × 1 m to 35 × 35 m. Because of the unique information inherently derived from these technologies before the fires, the areas were subsequently surveyed after the fires. We processed and provide free dissemination of these airborne datasets as products of surface reflectance, spectral metrics and forest structural metrics ( http://dx.doi.org/10.3334/ORNLDAAC/1288). These data products provide a unique opportunity to study relationships among and between remote sensing observations and fuel and fire characteristics (e.g., fuel type, condition, structure, and fire severity). The novelty of these data is not only in the unprecedented types of information available from them before, during, and after two megafires, but also in the synergistic use of multiple state of the art technologies for characterizing the environment. The synergy of these data can provide novel information that can improve maps of fuel type, structure, abundance, and condition that may improve predictions of megafire behavior and effects, thus aiding management before, during, and after such events. Key questions that these data could address include: What drives, extinguishes, and results from megafires? How does megafire behavior relate to fire and fuel management? How does the size and severity of a megafire affect the ecological recovery of the system? © 2016 by the Ecological Society of America.

Revised (Mixed-Effects) Estimation for Forest Burning Emissions of Gases and Smoke, Fire/Emission Factor Typology, and Potential Remote Sensing Classification of Types for Ozone and Black-Carbon Simulation

NASA Technical Reports Server (NTRS)

Chatfield, Robert B.; Segal Rozenhaimer, M.

2014-01-01

We summarize recent progress (a) in correcting biomass burning emissions factors deduced from airborne sampling of forest fire plumes, (b) in understanding the variability in reactivity of the fresh plumes sampled in ARCTAS (2008), DC3 (2012), and SEAC4RS (2013) airborne missions, and (c) in a consequent search for remotely sensed quantities that help classify forest-fire plumes. Particle properties, chemical speciation, and smoke radiative properties are related and mutually informative, as pictures below suggest (slopes of lines of same color are similar). (a) Mixed-effects (random-effects) statistical modeling provides estimates of both emission factors and a reasonable description of carbon-burned simultaneously. Different fire plumes will have very different contributions to volatile organic carbon reactivity; this may help explain differences of free NOx(both gas- and particle-phase), and also of ozone production, that have been noted for forest-fire plumes in California. Our evaluations check or correct emission factors based on sequential measurements (e.g., the Normalized Ratio Enhancement and similar methods). We stress the dangers of methods relying on emission-ratios to CO. (b) This work confirms and extends many reports of great situational variability in emissions factors. VOCs vary in OH reactivity and NOx-binding. Reasons for variability are not only fuel composition, fuel condition, etc., but are confused somewhat by rapid transformation and mixing of emissions. We use "unmixing" (distinct from mixed-effects) statistics and compare briefly to approaches like neural nets. We focus on one particularly intense fire the notorious Yosemite Rim Fire of 2013. In some samples, NOx activity was not so suppressed by binding into nitrates as in other fires. While our fire-typing is evolving and subject to debate, the carbon-burned delta(CO2+CO) estimates that arise from mixed effects models, free of confusion by background-CO2 variation, should provide a solid base for discussion. (c) We report progress using promising links we find between emissions-related "fire types" and promising features deducible from remote observations of plumes, e.g., single scatter albedo, Angstrom exponent of scattering, Angstrom exponent of absorption, (CO column density)/(aerosol optical depth).

Do multiple fires interact to affect vegetation structure in temperate eucalypt forests?

PubMed

Haslem, Angie; Leonard, Steve W J; Bruce, Matthew J; Christie, Fiona; Holland, Greg J; Kelly, Luke T; MacHunter, Josephine; Bennett, Andrew F; Clarke, Michael F; York, Alan

2016-12-01

Fire plays an important role in structuring vegetation in fire-prone regions worldwide. Progress has been made towards documenting the effects of individual fire events and fire regimes on vegetation structure; less is known of how different fire history attributes (e.g., time since fire, fire frequency) interact to affect vegetation. Using the temperate eucalypt foothill forests of southeastern Australia as a case study system, we examine two hypotheses about such interactions: (1) post-fire vegetation succession (e.g., time-since-fire effects) is influenced by other fire regime attributes and (2) the severity of the most recent fire overrides the effect of preceding fires on vegetation structure. Empirical data on vegetation structure were collected from 540 sites distributed across central and eastern Victoria, Australia. Linear mixed models were used to examine these hypotheses and determine the relative influence of fire and environmental attributes on vegetation structure. Fire history measures, particularly time since fire, affected several vegetation attributes including ground and canopy strata; others such as low and sub-canopy vegetation were more strongly influenced by environmental characteristics like rainfall. There was little support for the hypothesis that post-fire succession is influenced by fire history attributes other than time since fire; only canopy regeneration was influenced by another variable (fire type, representing severity). Our capacity to detect an overriding effect of the severity of the most recent fire was limited by a consistently weak effect of preceding fires on vegetation structure. Overall, results suggest the primary way that fire affects vegetation structure in foothill forests is via attributes of the most recent fire, both its severity and time since its occurrence; other attributes of fire regimes (e.g., fire interval, frequency) have less influence. The strong effect of environmental drivers, such as rainfall and topography, on many structural features show that foothill forest vegetation is also influenced by factors outside human control. While fire is amenable to human management, results suggest that at broad scales, structural attributes of these forests are relatively resilient to the effects of current fire regimes. Nonetheless, the potential for more frequent severe fires at short intervals, associated with a changing climate and/or fire management, warrant further consideration. © 2016 by the Ecological Society of America.

The Effects of Vegetative Type, Edges, Fire History, Rainfall and Management in Fire-Maintained Ecosystems

NASA Technical Reports Server (NTRS)

Breininger, David R.; Foster, Tammy E.; Carter, Geoffrey M.; Duncan, Brean W.; Stolen, Eric D.; Lyon, James E.

2017-01-01

The combined effects of repeated fires, climate, and landscape features (e.g., edges) need greater focus in fire ecology studies, which usually emphasize characteristics of the most recent fire and not fire history. Florida scrub-jays are an imperiled, territorial species that prefer medium (1.2-1.7 m) shrub heights. We measured short, medium, and tall habitat quality states annually within 10 ha grid cells that represented potential territories because frequent fires and vegetative recovery cause annual variation in habitat quality. We used multistate models and model selection to test competing hypotheses about how transition probabilities between states varied annually as functions of environmental covariates. Covariates included vegetative type, edges, precipitation, openings (gaps between shrubs), mechanical cutting, and fire characteristics. Fire characteristics not only included an annual presenceabsence of fire covariate, but also fire history covariates: time since the previous fire, the maximum fire-free interval, and the number of repeated fires. Statistical models with support included many covariates for each transition probability, often including fire history, interactions and nonlinear relationships. Tall territories resulted from 28 years of fire suppression and habitat fragmentation that reduced the spread of fires across landscapes. Despite 35 years of habitat restoration and prescribed fires, half the territories remained tall suggesting a regime shift to a less desirable habitat condition. Measuring territory quality states and environmental covariates each year combined with multistate modeling provided a useful empirical approach to quantify the effects of repeated fire in combinations with environmental variables on transition probabilities that drive management strategies and ecosystem change.

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 allow additional burning in an area with severe anthropogenic air pollution and where frequent widespread fire is both beneficial and inevitable. The more extensive air quality impacts documented with large high intensity fire may be averted by embracing the use of fire to prevent unwanted high intensity burns. A widespread increase in the use of fire for ecological benefit may provide the resiliency needed in Sierra Nevada forests as well as be the most beneficial to public health through the reduction of single dose exposure to smoke and limiting impacts spatially. Copyright © 2014 Elsevier Ltd. All rights reserved.

A fire-affected community: the case of the West Melton fire, December 2003

Treesearch

Laura Kelly; Pamela J. Jakes; E.R. Langer

2008-01-01

A study of a fire-affected community was conducted to gain an understanding of the social ramifications of a wildfire event and to analyse how one community responded to this type of disaster. The research focused on the West Melton community, located just west of Christchurch, in the Selwyn District. This is the first in a series of case studies planned by the Scion...

Prescribed burning in the pine regions of southern New Jersey and eastern shore Maryland - a summary of present knowledge

Treesearch

S. Little; H. A. Somes

1961-01-01

Twenty years ago the deliberate use of fire in forest management was frowned upon by many foresters. Many heated arguments developed over it, even though ecological studies had shown that fire favored the maintenance of several valuable forest types. Today attitudes have changed: most foresters accept fire as one of their management tools - though admittedly it is...

Fire Safety Aspects of Polymeric Materials. Volume 6. Aircraft. Civil and Military

DTIC Science & Technology

1977-01-01

resistance of the existing Polyurethane foam- based seating sys- tems be improved through design, construction, and selection of covering materials. 12. A...aircraft interiors under real fire conditions. To provide the data base for developing improved fire safety standards for aircraft, four types of...the determination of immobilizing effect was based on performance in the swimming test, a simple exercise method also favored by Kimmerle to provide

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.

Contrasts in short- and long-term responses of Mediterranean reptile species to fire and habitat structure.

PubMed

Santos, Xavier; Badiane, Arnaud; Matos, Cátia

2016-01-01

Changes in habitat structure constitute a major factor explaining responses of reptiles to fire. However, few studies have examined habitat factors that covary with fire-history variables to explain reptile responses. We hypothesise that more complex habitats should support richer reptile communities, and that species-specific relative abundance should be related to particular habitat features. From spring 2012-2014, twenty-five transects were surveyed in the Albera Region (north-east Iberia). The vegetation structure was measured and the extent of habitat types in a 1000-m buffer around each transect calculated. Reptile-community metrics (species richness and reptile abundance) were related to fire history, vegetation structure, and habitat types, using generalized additive models. These metrics correlated with habitat-structure variables but not with fire history. The number of species increased with more complex habitats but decreased with pine-plantation abundance in the 1000-m buffer. We found contrasting responses among reptiles in terms of time since fire and those responses differed according to vegetation variables and habitat types. An unplanned fire in August 2012 provided the opportunity to compare reptile abundance values between pre-fire and the short term (1-2 years) after the fire. Most species exhibited a negative short-term response to the 2012 fire except Tarentola mauritanica, a gecko that inhabits large rocks, as opposed to other ground-dwelling species. In the reptiles studied, contrasting responses to time since fire are consistent with the habitat-accommodation model of succession. These differences are linked to specific microhabitat preferences and suggest that functional traits can be used to predict species-specific responses to fire.

Fuel loads and fuel type mapping

USGS Publications Warehouse

Chuvieco, Emilio; Riaño, David; Van Wagtendonk, Jan W.; Morsdof, Felix; Chuvieco, Emilio

2003-01-01

Correct description of fuel properties is critical to improve fire danger assessment and fire behaviour modeling, since they guide both fire ignition and fire propagation. This chapter deals with properties of fuel that can be considered static in short periods of time: biomass loads, plant geometry, compactness, etc. Mapping these properties require a detail knowledge of vegetation vertical and horizontal structure. Several systems to classify the great diversity of vegetation characteristics in few fuel types are described, as well as methods for mapping them with special emphasis on those based on remote sensing images.

A system to evaluate fire impacts from simulated fire behavior in Mediterranean areas of Central Chile.

PubMed

Castillo, Miguel E; Molina, Juan R; Rodríguez Y Silva, Francisco; García-Chevesich, Pablo; Garfias, Roberto

2017-02-01

Wildfires constitute the greatest economic disruption to Mediterranean ecosystems, from a socio-economic and ecological perspective (Molina et al., 2014). This study proposes to classify fire intensity levels based on potential fire behavior in different types of Mediterranean vegetation types, using two geographical scales. The study considered >4 thousand wildfires over a period of 25years, identifying fire behavior on each event, based on simulations using "KITRAL", a model developed in Chile in 1993 and currently used in the entire country. Fire intensity values allowed results to be classified into six fire effects categories (levels), each of them with field indicators linking energy values with damage related to burned vegetation and wildland urban interface zone. These indicators also facilitated a preliminary assessment of wildfire impact on different Mediterranean land uses and, are therefore, a useful tool to prioritize future interventions. Copyright © 2016 Elsevier B.V. All rights reserved.

Fire safety of wood construction

Treesearch

Robert H. White; Mark A. Dietenberger

2010-01-01

Fire safety is an important concern in all types of construction. The high level of national concern for fire safety is reflected in limitations and design requirements in building codes. These code requirements and related fire performance data are discussed in the context of fire safety design and evaluation in the initial section of this chapter. Because basic data...

FireWorks curriculum featuring ponderosa, lodgepole, and whitebark pine forests

Treesearch

Jane Kapler Smith; Nancy E. McMurray

2000-01-01

FireWorks is an educational program for students in grades 1-10. The program consists of the curriculum in this report and a trunk of laboratory materials, specimens, and reference materials. It provides interactive, hands-on activities for studying fire ecology, fire behavior, and the influences of people on three fire-dependent forest types - Pinus ponderosa...

Davis Fire: Fire behavior and fire effects analysis

Treesearch

LaWen T. Hollingsworth

2010-01-01

The Davis Fire presents an interesting example of fire behavior in subalpine fir, partially dead lodgepole pine with multiple age classes, and moist site Douglas-fir vegetation types. This has been summer of moderate temperatures and intermittent moisture that has kept live herbaceous and live woody moistures fairly high and dead fuel moistures at a moderate level....

Fire risk in east-side forests.

Treesearch

Valerie. Rapp

2002-01-01

Wildfire was a natural part of ecosystems in east-side Oregon and Washington before the 20th century. The fire regimes, or characteristic patterns of fire—how often, how hot, how big, what time of year—helped create and maintain various types of forests.Forests are dynamic, and fire interacts with other ecological processes. Fires, forests...

29 CFR Appendix A to Subpart P to... - Model Fire Safety Plan (Non-Mandatory)

Code of Federal Regulations, 2011 CFR

2011-07-01

... Subpart P to Part 1915 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Fire Protection in Shipyard Employment Pt. 1915, Subpt. P, App. A Appendix A to Subpart P to Part 1915... fire. D. Potential ignition sources for fires and how to control them. E. Types of fire protection...

29 CFR Appendix A to Subpart P to... - Model Fire Safety Plan (Non-Mandatory)

Code of Federal Regulations, 2010 CFR

2010-07-01

... Subpart P to Part 1915 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Fire Protection in Shipyard Employment Pt. 1915, Subpt. P, App. A Appendix A to Subpart P to Part 1915... fire. D. Potential ignition sources for fires and how to control them. E. Types of fire protection...

Chapter 6: Fire damage of wood structures

Treesearch

B. Kukay; R.H. White; F. Woeste

2012-01-01

Depending on the severity, fire damage can compromise the structural integrity of wood structures such as buildings or residences. Fire damage of wood structures can incorporate several models that address (1) the type, cause, and spread of the fire, (2) the thermal gradients and fire-resistance ratings, and (3) the residual load capacity (Figure 6.1). If there is a...

Particulate and trace gas emissions from prescribed burns in southeastern U.S. fuel types: Summary of a 5-year project

Treesearch

David R. Weise; Timothy J. Johnson; James Reardon

2015-01-01

Management of smoke from prescribed fires requires knowledge of fuel quantity and the amount and composition of the smoke produced by the fire to minimize adverse impacts on human health. A five-year study produced new emissions information for more than 100 trace gases and particulate matter in smoke for fuel types found in the southern United States of America using...

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

Zarnoch, Stanley J.; Blake, John I.; Parresol, Bernard R.

Snags are standing dead trees that are an important component in the nesting habitat of birds and other species. Although snag availability is believed to limit populations in managed and non-managed forests, little data are available to evaluate the relative effect of stand conditions and management on snag occurrence. We analyzed point sample data from an intensive forest inventory within an 80,000 ha landscape for four major forest types to support the hypotheses that routine low-intensity prescribed fire would increase, and thinning would decrease, snag occurrence. We employed path analysis to define a priori causal relationships to determine the directmore » and indirect effects of site quality, age, relative stand density index and fire for all forest types and thinning effects for loblolly pine and longleaf pine. Stand age was an important direct effect for loblolly pine, mixed pine-hardwoods and hardwoods, but not for longleaf pine. Snag occurrence in loblolly pine was increased by prescribed fire and decreased by thinning which confirmed our initial hypotheses. Although fire was not important in mixed pine-hardwoods, it was for hardwoods but the relationship depended on site quality. For longleaf pine the relative stand density index was the dominant variable affecting snag occurrence, which increased as the density index decreased. Site quality, age and thinning had significant indirect effects on snag occurrence in longleaf pine through their effects on the density index. Although age is an important condition affecting snag occurrence for most forest types, path analysis revealed that fire and density management practices within certain forest types can also have major beneficial effects, particularly in stands less than 60 years old.« less

Who's driving?: Separating Fire, CO2, and Climate Change Influences on Vegetation and Carbon Dynamics on MC2 Results for Western Oregon and Washington, United States

NASA Astrophysics Data System (ADS)

Sheehan, T.; Bachelet, D. M.; Ferschweiler, K.

2016-12-01

For Oregon and Washington west of the Cascade Mountain crest, results from the MC2 global dynamic vegetation model have projected a shift in potential vegetation type from predominantly conifer to predominantly mixed forest over the 21st century, with a shift from mixed to conifer in some areas. Carbon stocks have been projected to fall over this period. We ran MC2 using the CCSM4 RCP 8.5 climate future downscaled to 2.5 arc minute resolution with 5 different configurations: no fire; assumed ignitions without fire suppression; assumed ignitions with fire suppression; assumed ignitions with fire suppression and with CO2 concentration held at the preindustrial level; and stochastic ignitions without fire suppression. Results show that vegetation change is the result of climate change alone, while carbon is influenced by both fire occurrence and CO2-induced increased water use efficiency. While model results do not indicate a large change in carbon dynamics concomitant with the shift in vegetation, it is reasonable to expect that a change in conditions resulting in such a change in vegetation type would stress the existing vegetation resulting in some mortality and loss of live carbon.

Effects of prescribed burning and litter type on litter decomposition and nutrient release in mixed-grass prairie in Eastern Montana

USDA-ARS?s Scientific Manuscript database

Fire can affect litter decomposition and carbon (C) and nitrogen (N) dynamics. Here, we examined the effect of summer fire and three litter types on litter decomposition and litter C and N dynamics in a northern mixed-grass prairie over a 24 month period starting ca. 14 months after fire. Over all...

Self-extinguishing behavior of kerosene spray fire in a completely enclosed compartment

NASA Astrophysics Data System (ADS)

Wang, Changjian; Guo, Jin; Yan, Weigang; Lu, Shouxiang

2013-10-01

The self-extinguishing behavior of kerosene spray fire was investigated in a completely enclosed compartment with the size of 3 m × 3 m × 3.4 m. The spray was generated by locating one BETE nozzle at the center of the bottom wall. A series of spray fire videos were obtained by changing BETE nozzle type and injecting pressure. The results show that spray fire undergoes four stages: the growth stage, the quasi-steady stage, the stretch stage and the self-extinguishing stage. Consumption of large quantities of oxygen causes spray fire to first be stretched and then quench. In this process, fire base migrates away from spray region and leads to the emergence of ghosting fire. Ghosting fire promotes the instability of spray fire and large fluctuation of its height, which provides help to its self-extinguishing. With increasing the injecting pressure or the nozzle diameter, the self-extinguishing time decreases. It is found that the self-extinguishing time is approximately in inverse relation with injecting flow rate. Additionally, we also observed the occurrence of two-phase deflagration just after ignition, and it accelerates the spray fire growth and induces a larger fire height than the following quasi-steady spray fire. The deflagration turns stronger with increasing the injecting pressure.

Fire frequency in the Interior Columbia River Basin: Building regional models from fire history data

USGS Publications Warehouse

McKenzie, D.; Peterson, D.L.; Agee, James K.

2000-01-01

Fire frequency affects vegetation composition and successional pathways; thus it is essential to understand fire regimes in order to manage natural resources at broad spatial scales. Fire history data are lacking for many regions for which fire management decisions are being made, so models are needed to estimate past fire frequency where local data are not yet available. We developed multiple regression models and tree-based (classification and regression tree, or CART) models to predict fire return intervals across the interior Columbia River basin at 1-km resolution, using georeferenced fire history, potential vegetation, cover type, and precipitation databases. The models combined semiqualitative methods and rigorous statistics. The fire history data are of uneven quality; some estimates are based on only one tree, and many are not cross-dated. Therefore, we weighted the models based on data quality and performed a sensitivity analysis of the effects on the models of estimation errors that are due to lack of cross-dating. The regression models predict fire return intervals from 1 to 375 yr for forested areas, whereas the tree-based models predict a range of 8 to 150 yr. Both types of models predict latitudinal and elevational gradients of increasing fire return intervals. Examination of regional-scale output suggests that, although the tree-based models explain more of the variation in the original data, the regression models are less likely to produce extrapolation errors. Thus, the models serve complementary purposes in elucidating the relationships among fire frequency, the predictor variables, and spatial scale. The models can provide local managers with quantitative information and provide data to initialize coarse-scale fire-effects models, although predictions for individual sites should be treated with caution because of the varying quality and uneven spatial coverage of the fire history database. The models also demonstrate the integration of qualitative and quantitative methods when requisite data for fully quantitative models are unavailable. They can be tested by comparing new, independent fire history reconstructions against their predictions and can be continually updated, as better fire history data become available.

Anthropogenic and Climatic Influence on Vegetation Fires in Peatland of Insular Southeast Asia

NASA Astrophysics Data System (ADS)

Liew, S.; Miettinen, J.; Salinas Cortijo, S. V.

2011-12-01

Fire is traditionally used as a tool in land clearing by farmers and shifting cultivators in Southeast Asia. However, the small scale clearing of land is increasingly being replaced by modern large-scale conversion of forests into plantations/agricultural land, usually also by fires. Fires get out of control in periods of extreme drought, especially during the El Nino periods, resulting in severe episodes of transboundary air pollution in the form of smoke haze. We use the MODIS active fires product (hotspots) to establish correlations between the temporal and spatial patterns of vegetation fires with climatic variables, land cover change and soil type (peat or non-peat) in the western part of Insular Southeast Asia for a decade from 2001 to 2010. Fire occurrence exhibits a negative correlation with rainfall, and is more severe overall during the El-Nino periods. However, not all regions are equally affected by El-Nino. In Southern Sumatra and Southern Borneo the correlation with El-Nino is high. However, fires in some regions such as the peatland in Riau, Jambi and Sarawak do not appear to be influenced by El-Nino. These regions are also experiencing rapid conversion of forest to large scale plantations.

Aerosol emissions by tropical forest and savanna biomass burning: Characteristic trace elements and fluxes

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

Echalar, F.; Gaudichet, A.; Cachier, H.

1995-11-15

This report characterizes and compares trace element emissions from fires of three different types of savannas and from the southwestern amazonian rain forest. This study tries to verify a fingerprint that may characterize savanna fires or tropical biomass burning.

Predicted fire behavior and societal benefits in three eastern Sierra Nevada vegetation types

Treesearch

C.A. Dicus; K. Delfino; D.R. Weise

2009-01-01

We investigated potential fire behavior and various societal benefits (air pollution removal, carbon sequestration, and carbon storage) provided by woodlands of pinyon pine (Pinus monophylla) and juniper (Juniperus californica), shrublands of Great Basin sagebrush (Artemisia tridentata) and rabbitbrush (Ericameria nauseosa...

Estradiol-Dependent Stimulation and Suppression of Gonadotropin-Releasing Hormone Neuron Firing Activity by Corticotropin-Releasing Hormone in Female Mice.

PubMed

Phumsatitpong, Chayarndorn; Moenter, Suzanne M

2018-01-01

Gonadotropin-releasing hormone (GnRH) neurons are the final central regulators of reproduction, integrating various inputs that modulate fertility. Stress typically inhibits reproduction but can be stimulatory; stress effects can also be modulated by steroid milieu. Corticotropin-releasing hormone (CRH) released during the stress response may suppress reproduction independent of downstream glucocorticoids. We hypothesized CRH suppresses fertility by decreasing GnRH neuron firing activity. To test this, mice were ovariectomized (OVX) and either implanted with an estradiol capsule (OVX+E) or not treated further to examine the influence of estradiol on GnRH neuron response to CRH. Targeted extracellular recordings were used to record firing activity from green fluorescent protein-identified GnRH neurons in brain slices before and during CRH treatment; recordings were done in the afternoon when estradiol has a positive feedback effect to increase GnRH neuron firing. In OVX mice, CRH did not affect the firing rate of GnRH neurons. In contrast, CRH exhibited dose-dependent stimulatory (30 nM) or inhibitory (100 nM) effects on GnRH neuron firing activity in OVX+E mice; both effects were reversible. The dose-dependent effects of CRH appear to result from activation of different receptor populations; a CRH receptor type-1 agonist increased firing activity in GnRH neurons, whereas a CRH receptor type-2 agonist decreased firing activity. CRH and specific agonists also differentially regulated short-term burst frequency and burst properties, including burst duration, spikes/burst, and/or intraburst interval. These results indicate that CRH alters GnRH neuron activity and that estradiol is required for CRH to exert both stimulatory and inhibitory effects on GnRH neurons. Copyright © 2018 Endocrine Society.

Variation in soil enzyme activity as a function of vegetation amount, type, and spatial structure in fire-prone Mediterranean shrublands.

PubMed

Mayor, Ángeles G; Goirán, Silvana B; Vallejo, V Ramón; Bautista, Susana

2016-12-15

Fire-prone Mediterranean shrublands may be seriously threatened by land degradation due to progressive opening of the vegetation cover driven by increasing drought and fire recurrence. However, information about the consequences of this opening process for critical ecosystem functions is scant. In this work, we studied the influence of vegetation amount, type, and spatial pattern in the variation of extracellular soil enzyme activity (acid phosphatase, β-glucosidase, and urease) in fire-prone shrublands in eastern Spain. Soil was sampled in vegetation-patch and open-interpatch microsites in 15 shrubland sites affected by large wildfires in 1991. On average, the activities of the three enzymes were 1.5 (β-glucosidase and urease) to 1.7 (acid phosphatase) times higher in soils under vegetation patches than in adjacent interpatches. In addition, phosphatase activity for both microsites significantly decreased with the fragmentation of the vegetation. This result was attributed to a lower influence of roots -the main source of acid phosphatase- in the bigger interpatches of the sites with lower patch cover, and to feedbacks between vegetation pattern, redistribution of resources, and soil quality during post-fire vegetation dynamics. Phosphatase activity was also 1.2 times higher in patches of resprouter plants than in patches of non-resprouters, probably due to the faster post-fire recovery and older age of resprouter patches in these fire-prone ecosystems. The influence on the studied enzymes of topographic and climatic factors acting at the landscape scale was insignificant. According to our results, variations in the cover, pattern, and composition of vegetation patches may have profound impacts on soil enzyme activity and associated nutrient cycling processes in fire-prone Mediterranean shrublands, particularly in those related to phosphorus. Copyright © 2016 Elsevier B.V. All rights reserved.

30 CFR 75.1107-8 - Fire suppression devices; extinguishant supply systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Fire suppression devices; extinguishant supply systems. (a) Fire suppression systems using water or... equivalent protective devices and a rising stem or other visual indicator-type shutoff valve. (b) Water supplies for fire suppression devices installed on underground equipment may be maintained in mounted water...

30 CFR 75.1107-8 - Fire suppression devices; extinguishant supply systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Fire suppression devices; extinguishant supply systems. (a) Fire suppression systems using water or... equivalent protective devices and a rising stem or other visual indicator-type shutoff valve. (b) Water supplies for fire suppression devices installed on underground equipment may be maintained in mounted water...

30 CFR 75.1107-8 - Fire suppression devices; extinguishant supply systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Fire suppression devices; extinguishant supply systems. (a) Fire suppression systems using water or... equivalent protective devices and a rising stem or other visual indicator-type shutoff valve. (b) Water supplies for fire suppression devices installed on underground equipment may be maintained in mounted water...

Comparative Analysis of the Reliability of Steel Structure with Pinned and Rigid Nodes Subjected to Fire

NASA Astrophysics Data System (ADS)

Kubicka, Katarzyna; Radoń, Urszula; Szaniec, Waldemar; Pawlak, Urszula

2017-10-01

The paper concerns the reliability analysis of steel structures subjected to high temperatures of fire gases. Two types of spatial structures were analysed, namely with pinned and rigid nodes. The fire analysis was carried out according to prescriptions of Eurocode. The static-strength analysis was conducted using the finite element method (FEM). The MES3D program, developed by Szaniec (Kielce University of Technology, Poland), was used for this purpose. The results received from MES3D made it possible to carry out the reliability analysis using the Numpress Explore program that was developed at the Institute of Fundamental Technological Research of the Polish Academy of Sciences [9]. The measurement of reliability of structures is the Hasofer-Lind reliability index (β). The reliability analysis was carried out according to approximation (FORM, SORM) and simulation (Importance Sampling, Monte Carlo) methods. As the fire progresses, the value of reliability index decreases. The analysis conducted for the study made it possible to evaluate the impact of node types on those changes. In real structures, it is often difficult to define correctly types of nodes, so some simplifications are made. The presented analysis contributes to the recognition of consequences of such assumptions for the safety of structures, subjected to fire.

Charring temperatures are driven by the fuel types burned in a peatland wildfire

PubMed Central

Hudspith, Victoria A.; Belcher, Claire M.; Yearsley, Jonathan M.

2014-01-01

Peatlands represent a globally important carbon store; however, the human exploitation of this ecosystem is increasing both the frequency and severity of fires on drained peatlands. Yet, the interactions between the hydrological conditions (ecotopes), the fuel types being burned, the burn severity, and the charring temperatures (pyrolysis intensity) remain poorly understood. Here we present a post-burn assessment of a fire on a lowland raised bog in Co. Offaly, Ireland (All Saints Bog). Three burn severities were identified in the field (light, moderate, and deeply burned), and surface charcoals were taken from 17 sites across all burn severities. Charcoals were classified into two fuel type categories (either ground or aboveground fuel) and the reflectance of each charcoal particle was measured under oil using reflectance microscopy. Charcoal reflectance shows a positive relationship with charring temperature and as such can be used as a temperature proxy to reconstruct minimum charring temperatures after a fire event. Resulting median reflectance values for ground fuels are 1.09 ± 0.32%Romedian, corresponding to estimated minimum charring temperatures of 447°C ± 49°C. In contrast, the median charring temperatures of aboveground fuels were found to be considerably higher, 646°C ± 73°C (3.58 ± 0.77%Romedian). A mixed-effects modeling approach was used to demonstrate that the interaction effects of burn severity, as well as ecotope classes, on the charcoal reflectance is small compared to the main effect of fuel type. Our findings reveal that the different fuel types on raised bogs are capable of charring at different temperatures within the same fire, and that the pyrolysis intensity of the fire on All Saints Bog was primarily driven by the fuel types burning, with only a weak association to the burn severity or ecotope classes. PMID:25566288

Fire prevention in California's Riverside County Headstart Project...an evaluation

Treesearch

William S. Folkman; Jean Taylor

1972-01-01

An especially designed series of fire prevention lessons were taught to preschool children in the Headstart Project in Riverside County, Calif. Their effectiveness was evaluated by observing classroom reaction and by testing the children at the end of the year. The results suggest that this type of educational approach is feasible.

LOW CONCENTRATION MERCURY SORPTION MECHANISMS AND CONTROL BY CALCIUM-BASED SORBENTS; APPLICATION IN COAL-FIRED PROCESSES

EPA Science Inventory

The capture of elemental mercury (Hgo) and mercuric chloride (HgCl2) by three types of calcium (Ca)-based sorbents was examined in this bench-scale study under conditions prevalent in coal fired utilities. Ca-based sorbent performances were compared to that of an activated carbon...

Regional patterns of cropland and pasture burning: Statistical separation of signals from remote sensing products

NASA Astrophysics Data System (ADS)

Rabin, S. S.; Pacala, S. W.; Magi, B. I.; Shevliakova, E.

2013-12-01

The use of fire in agriculture--to manage crop residues and pastoral grasses, and for clearing land--has consequences worldwide for air quality, human health, and climate. Airborne particulate matter from such burning aggravates respiratory ailments and can influence regional precipitation, while associated greenhouse gases and aerosols affect global climate. Little research, however, has focused on understanding patterns of cropland and pasture fire use with an eye towards simulation at global scales. Previous work by these authors showed that the separate seasonal trends of agricultural and non-agricultural fire could be extracted from large-scale fire observation and land use datasets. This study builds on that research, describing the derivation and application of a statistical method to estimate both the seasonality and amount of cropland, pasture, and other fire based on observations from satellite-based remote sensing products. We demonstrate that our approach is flexible enough to allow the incorporation of alternative high-quality observations of fire and/or land use that might be available only for certain regions. Results for a number of large regions around the world show that these two kinds of agricultural fire often differ in their extent and seasonality from each other and from burning on other land in ways that reflect known management practices. For example, we find that pasture in north-central sub-Saharan Africa tends to burn earlier than non-agricultural land; this can be attributed to pastoralists preventively burning their land early in the dry season so as to avoid severe, uncontrolled burns under more dangerous fire conditions later. Both the timing and extent of agricultural fires prove to be regionally specific; our method allows these geographically distinct patterns to be fully appreciated. The local and global differences in seasonality and amount of fire between different land-use types suggest that dynamic global vegetation models (DGVMs) should simulate fires on cropland and pasture fire independently from burning on other lands and take a regional approach in doing so. For example, pastoral burning dominates across large parts of the African region described above, where a fire model focused only on non-agricultural burning would therefore be inaccurate. On the other hand, in southern Africa those two types of fire more closely parallel each other. While a pure application of our analytical method is based exclusively on the relative distributions of fire activity and land use types, we demonstrate its incorporation into a more process-based fire model to capture the influence of seasonal and interannual variations in climate and ecosystem characteristics on burning. Such a model, the ultimate goal of our research, will help improve DGVM simulations--and therefore scientific understanding--of past, present, and future distributions of fire.

Garrison Project - Lake Sakakawea Oil and Gas Management Plan, North Dakota

DTIC Science & Technology

2012-11-01

When the air gun is fired , pulses of acoustic energy are produced causing the shock waves needed for data collection (Peterson, 2004). • Seismic...The proposed casing program shall include the size, weight, grade, and length of casing proposed, type of thread and coupling, and setting depth of...suppression of fires on public lands caused by its employees, contractors or subcontractors. During conditions of extreme fire danger, surface use

Fire severity, size, and climate associations diverge from historical precedent along an ecological gradient in the Pinaleno Mountains, Arizona, USA

Treesearch

Christopher D. O' Connor; Donald A. Falk; Ann M. Lynch; Thomas W. Swetnam

2014-01-01

In recent decades fire size and severity have been increasing in high elevation forests of the American Southwest. Ecological outcomes of these increases are difficult to gauge without an historical context for the role of fire in these systems prior to interruption by Euro-American land uses. Across the gradient of forest types in the Pinaleño Mountains, a Sky Island...

Presettlement fire regime and vegetation mapping in Southeastern Coastal Plain forest ecosystems

Treesearch

Andrew D. Bailey; Robert Mickler; Cecil Frost

2007-01-01

Fire-adapted forest ecosystems make up 95 percent of the historic Coastal Plain vegetation types in the Southeastern United States. Fire suppression over the last century has altered the species composition of these ecosystems, increased fuel loads, and increased wildfire risk. Prescribed fire is one management tool used to reduce fuel loading and restore fire-adapted...

Estimating canopy fuels in conifer forests

Treesearch

Joe H. Scott; Elizabeth D. Reinhardt

2002-01-01

Crown fires occur in a variety of coniferous forest types (Agee 1993), including some that are not historically prone to crown fire, such as ponderosa pine (Mutch and others 1993). The head fire spread rate of a crown fire is usually several times faster than that of a surface fire burning under the same conditions, which leads to a significant increase in the number...

Szendro - type Integrated Vegetation Fire Management--Wildfire Management Program from Hungary

Treesearch

Ágoston Restás

2006-01-01

Szendrő Fire Department is located in the northeastern part of Hungary. The main task is to fight against wildfire and mitigate the impact of fire at the Aggtelek National Park -- which belongs to the UNESCO World Heritage list. Because of greater effectiveness, in 2004 the Fire Department started a project named Integrated Vegetation Fire Management (IVFM)....

Forest fire risk zonation mapping using remote sensing technology

NASA Astrophysics Data System (ADS)

Chandra, Sunil; Arora, M. K.

2006-12-01

Forest fires cause major losses to forest cover and disturb the ecological balance in our region. Rise in temperature during summer season causing increased dryness, increased activity of human beings in the forest areas, and the type of forest cover in the Garhwal Himalayas are some of the reasons that lead to forest fires. Therefore, generation of forest fire risk maps becomes necessary so that preventive measures can be taken at appropriate time. These risk maps shall indicate the zonation of the areas which are in very high, high, medium and low risk zones with regard to forest fire in the region. In this paper, an attempt has been made to generate the forest fire risk maps based on remote sensing data and other geographical variables responsible for the occurrence of fire. These include altitude, temperature and soil variations. Key thematic data layers pertaining to these variables have been generated using various techniques. A rule-based approach has been used and implemented in GIS environment to estimate fuel load and fuel index leading to the derivation of fire risk zonation index and subsequently to fire risk zonation maps. The fire risk maps thus generated have been validated on the ground for forest types as well as for forest fire risk areas. These maps would help the state forest departments in prioritizing their strategy for combating forest fires particularly during the fire seasons.

A comparison of effects from prescribed fires and wildfires managed for resource objectives in Sequoia and Kings Canyon National Parks

USGS Publications Warehouse

Nesmith, C.B.; Caprio, Anthony C.; Pfaff, Anne H.; McGinnis, Thomas W.; Keeley, Jon E.

2011-01-01

Current goals for prescription burning are focused on measures of fuel consumption and changes in forest density. These benchmarks, however, do not address the extent to which prescription burning meets perceived ecosystem needs of heterogeneity in burning, both for overstory trees and understory herbs and shrubs. There are still questions about how closely prescribed fires mimic these patterns compared to natural wildfires. This study compared burn patterns of prescribed fires and managed unplanned wildfires to understand how the differing burning regimes affect ecosystem properties. Measures of forest structure and fire severity were sampled in three recent prescribed fires and three wildfires managed for resource objectives in Sequoia and Kings Canyon National Parks. Fine scale patterns of fire severity and heterogeneity were compared between fire types using ground-based measures of fire effects on fuels and overstory and understory vegetation. Prescribed fires and wildfires managed for resource objectives displayed similar patterns of overstory and understory fire severity, heterogeneity, and seedling and sapling survival. Variation among plots within the same fire was always greater than between fire types. Prescribed fires can provide burned landscapes that approximate natural fires in many ways. It is recognized that constraints placed on when wildfires managed for resource objectives are allowed to burn freely may bias the range of conditions that might have been experienced under more natural conditions. Therefore they may not exactly mimic natural wildfires. Overall, the similarity in fire effects that we observed between prescribed fires and managed wildfires indicate that despite the restrictions that are often placed on prescribed fires, they appear to be creating post-fire conditions that approximate natural fires when assessed on a fine spatial scale.

Electronic equipment vulnerability to fire released carbon fibers

NASA Technical Reports Server (NTRS)

Pride, R. A.; Mchatton, A. D.; Musselman, K. A.

1980-01-01

The vulnerability of electronic equipment to damage by carbon fibers released from burning aircraft type structural composite materials was investigated. Tests were conducted on commercially available stereo power amplifiers which showed that the equipment was damaged by fire released carbon fibers but not by the composite resin residue, soot and products of combustion of the fuel associated with burning the carbon fiber composites. Results indicate that the failure rates of the equipment exposed to the fire released fiber were consistent with predictions based on tests using virgin fibers.

The StreamCat Dataset: Accumulated Attributes for NHDPlusV2 Catchments Riparian Buffer (Version 2.1) for the Conterminous United States: Wildland Fire Perimeters By Year 2000 - 2010

EPA Pesticide Factsheets

This dataset represents the historical fire perimeters within individual local NHDPlusV2 catchments and upstream, contributing watersheds riparian buffers based on the GeoMAC (Geospatial Multi-Agency Coordination) mapping tool (See Supplementary Info for Glossary of Terms). Fire perimeters contain data as they are submitted by field offices to GeoMAC (Geospatial Multi-Agency Coordination) in a polygon format. Fire perimeter data is based on input from incident intelligence sources, GPS data, infrared (IR) imagery from fixed wing and satellite platforms. Polygons are selected by year and then converted into a binary raster format where values of 1 represent fire perimeters of the given year and 0 describes the remaining areas across the CONUS, leaving No Data to be anything outside the CONUS border. The wildland fire characteristics (% forest loss to fire) were summarized by year to produce local catchment-level and watershed-level metrics as a continuous data type (see Data Structure and Attribute Information for a description).

The StreamCat Dataset: Accumulated Attributes for NHDPlusV2 Catchments (Version 2.1) for the Conterminous United States: Wildland Fire Perimeters By Year 2000 - 2010

EPA Pesticide Factsheets

This dataset represents the historical fire perimeters within individual local NHDPlusV2 catchments and upstream, contributing watersheds based on the GeoMAC (Geospatial Multi-Agency Coordination) mapping tool (See Supplementary Info for Glossary of Terms). Fire perimeters contain data as they are submitted by field offices to GeoMAC (Geospatial Multi-Agency Coordination) in a polygon format. Fire perimeter data is based on input from incident intelligence sources, GPS data, infrared (IR) imagery from fixed wing and satellite platforms. Polygons are selected by year and then converted into a binary raster format where values of 1 represent fire perimeters of the given year and 0 describes the remaining areas across the CONUS, leaving No Data to be anything outside the CONUS border. The wildland fire characteristics (% forest loss to fire) were summarized by year to produce local catchment-level and watershed-level metrics as a continuous data type (see Data Structure and Attribute Information for a description).

The Influence of Proximity to a National Forest on Emotions and Fire-Management Decisions

NASA Astrophysics Data System (ADS)

Vining, Joanne; Merrick, Melinda S.

2008-02-01

Because American national forests are managed for all citizens, it is important that researchers explore the differences and similarities between citizens living both near and far from publicly managed land. We surveyed residents living at various distances from nationally managed land to collect resident perceptions of different forest fire-management techniques, to determine public preferences for these techniques, and to examine the motivations behind these preferences. Participants both close to and far away from national forests tended to favor a multipronged approach to fire management by preferring the use of a combination of two or more fire-management techniques. There were no significant differences by proximity in participants’ self-rated emotions, types of fire-management techniques preferred, or the reasons and rationales for their preferred fire-management technique(s), indicating that the proximity variable may not be as significant as previously thought.

The influence of proximity to a national forest on emotions and fire-management decisions.

PubMed

Vining, Joanne; Merrick, Melinda S

2008-02-01

Because American national forests are managed for all citizens, it is important that researchers explore the differences and similarities between citizens living both near and far from publicly managed land. We surveyed residents living at various distances from nationally managed land to collect resident perceptions of different forest fire-management techniques, to determine public preferences for these techniques, and to examine the motivations behind these preferences. Participants both close to and far away from national forests tended to favor a multipronged approach to fire management by preferring the use of a combination of two or more fire-management techniques. There were no significant differences by proximity in participants' self-rated emotions, types of fire-management techniques preferred, or the reasons and rationales for their preferred fire-management technique(s), indicating that the proximity variable may not be as significant as previously thought.

Basal Ganglia Outputs Map Instantaneous Position Coordinates during Behavior

PubMed Central

Barter, Joseph W.; Li, Suellen; Sukharnikova, Tatyana; Rossi, Mark A.; Bartholomew, Ryan A.

2015-01-01

The basal ganglia (BG) are implicated in many movement disorders, yet how they contribute to movement remains unclear. Using wireless in vivo recording, we measured BG output from the substantia nigra pars reticulata (SNr) in mice while monitoring their movements with video tracking. The firing rate of most nigral neurons reflected Cartesian coordinates (either x- or y-coordinates) of the animal's head position during movement. The firing rates of SNr neurons are either positively or negatively correlated with the coordinates. Using an egocentric reference frame, four types of neurons can be classified: each type increases firing during movement in a particular direction (left, right, up, down), and decreases firing during movement in the opposite direction. Given the high correlation between the firing rate and the x and y components of the position vector, the movement trajectory can be reconstructed from neural activity. Our results therefore demonstrate a quantitative and continuous relationship between BG output and behavior. Thus, a steady BG output signal from the SNr (i.e., constant firing rate) is associated with the lack of overt movement, when a stable posture is maintained by structures downstream of the BG. Any change in SNr firing rate is associated with a change in position (i.e., movement). We hypothesize that the SNr output quantitatively determines the direction, velocity, and amplitude of voluntary movements. By changing the reference signals to downstream position control systems, the BG can produce transitions in body configurations and initiate actions. PMID:25673860

An organizational process for promoting home fire safety in two community settings.

PubMed

Lehna, Carlee; Twyman, Stephanie; Fahey, Erin; Coty, Mary-Beth; Williams, Joe; Scrivener, Drane; Wishnia, Gracie; Myers, John

2017-02-01

The purpose of this study was to describe the home fire safety quality improvement model designed to aid organizations in achieving institutional program goals. The home fire safety model was developed from community-based participatory research (CBPR) applying training-the-trainer methods and is illustrated by an institutional case study. The model is applicable to other types of organizations to improve home fire safety in vulnerable populations. Utilizing the education model leaves trained employees with guided experience to build upon, adapt, and modify the home fire safety intervention to more effectively serve their clientele, promote safety, and meet organizational objectives. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

46 CFR 62.35-15 - Fire safety.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Fire safety. 62.35-15 Section 62.35-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING VITAL SYSTEM AUTOMATION Requirements for Specific Types of Automated Vital Systems § 62.35-15 Fire safety. (a) All required fire pump...

46 CFR 62.35-15 - Fire safety.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Fire safety. 62.35-15 Section 62.35-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING VITAL SYSTEM AUTOMATION Requirements for Specific Types of Automated Vital Systems § 62.35-15 Fire safety. (a) All required fire pump...

Fire Prevention Inspection Procedures.

ERIC Educational Resources Information Center

Pribyl, Paul F.

Lesson plans are provided for a fire prevention inspection course of the Wisconsin Fire Service Training program. Objectives for the course are to enable students to describe and conduct fire prevention inspections, to identify and correct hazards common to most occupancies, to understand the types of building construction and occupancy, and to…

Soil organic matter composition and quality across fire severity gradients in coniferous and deciduous forests of the southern boreal region

NASA Astrophysics Data System (ADS)

Miesel, Jessica R.; Hockaday, William C.; Kolka, Randall K.; Townsend, Philip A.

2015-06-01

Recent patterns of prolonged regional drought in southern boreal forests of the Great Lakes region, USA, suggest that the ecological effects of disturbance by wildfire may become increasingly severe. Losses of forest soil organic matter (SOM) during fire can limit soil nutrient availability and forest regeneration. These processes are also influenced by the composition of postfire SOM. We sampled the forest floor layer (i.e., full organic horizon) and 0-10 cm mineral soil from stands dominated by coniferous (Pinus banksiana Lamb.) or deciduous (Populus tremuloides Michx.) species 1-2 months after the 2011 Pagami Creek wildfire in northern Minnesota. We used solid-state 13C NMR to characterize SOM composition across a gradient of fire severity in both forest cover types. SOM composition was affected by fire, even when no statistically significant losses of total C stocks were evident. The most pronounced differences in SOM composition between burned and unburned reference areas occurred in the forest floor for both cover types. Carbohydrate stocks in forest floor and mineral horizons decreased with severity level in both cover types, whereas pyrogenic C stocks increased with severity in the coniferous forest floor and decreased in only the highest severity level in the deciduous forest floor. Loss of carbohydrate and lignin pools contributed to a decreased SOM stability index and increased decomposition index. Our results suggest that increases in fire severity expected to occur under future climate scenarios may lead to changes in SOM composition and dynamics with consequences for postfire forest recovery and C uptake.

[Patterns of action potential firing in cortical neurons of neonatal mice and their electrophysiological property].

PubMed

Furong, Liu; Shengtian, L I

2016-05-25

To investigate patterns of action potential firing in cortical heurons of neonatal mice and their electrophysiological properties. The passive and active membrane properties of cortical neurons from 3-d neonatal mice were observed by whole-cell patch clamp with different voltage and current mode. Three patterns of action potential firing were identified in response to depolarized current injection. The effects of action potential firing patterns on voltage-dependent inward and outward current were found. Neurons with three different firing patterns had different thresholds of depolarized current. In the morphology analysis of action potential, the three type neurons were different in rise time, duration, amplitude and threshold of the first action potential evoked by 80 pA current injection. The passive properties were similar in three patterns of action potential firing. These results indicate that newborn cortical neurons exhibit different patterns of action potential firing with different action potential parameters such as shape and threshold.

The change in motor unit firing rates at de-recruitment relative to recruitment is correlated with type I myosin heavy chain isoform content of the vastus lateralis in vivo.

PubMed

Herda, T J; Miller, J D; Trevino, M A; Mosier, E M; Gallagher, P M; Fry, A C; Vardiman, J P

2016-04-01

To investigate the change in motor unit (MU) firing rates (FR) at de-recruitment relative to recruitment and the relation to % type I myosin heavy chain isoform content (type I %MHC) of the vastus lateralis (VL) in vivo. Ten subjects performed a 22-s submaximal isometric trapezoid muscle action that included a linearly increasing, steady force at 50% maximal voluntary contraction, and linearly decreasing segments. Surface electromyographic signals were collected from the VL and were decomposed into constituent MU action potentials trains. A tissue sample from the VL was taken to calculate type I %MHC. The y-intercepts and slopes were calculated for the changes (Δ) in FR at de-recruitment (FRDEREC ) relative to FR at recruitment (FRREC ) vs. FRREC relationship for each subject. Correlations were performed between the y-intercepts and slopes with type I %MHC. The majority of MUs had greater FRDEREC than FRREC . The y-intercepts (r = -0.600, P = 0.067) were not significantly correlated, but the slopes (r = -0.793, P = 0.006) were significantly correlated with type I %MHC. The majority of the motoneuron pool had greater FRDEREC than FRREC , however, individuals with higher type I %MHC had a greater propensity to have MUs with FRREC > FRDEREC as indicated by the slope values. Overall, the contractile properties of the muscle (MHC) could partially explain the differences in MU firing rates at de-recruitment relative to recruitment. Thus, suggesting the fatigability of the muscle influences the alterations in MU firing rates from recruitment to de-recruitment. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

A study of forest fire danger district division in Lushan Mountain based on RS and GIS

NASA Astrophysics Data System (ADS)

Xiao, Jinxiang; Huang, Shu-E.; Zhong, Anjian; Zhu, Biqin; Ye, Qing; Sun, Lijun

2009-09-01

The study selected 9 factors, average maximum temperature, average temperature, average precipitation, average the longest days of continuous drought and average wind speed during fire prevention period, vegetation type, altitude, slope and aspect as the index of forest fire danger district division, which has taken the features of Lushan Mountain's forest fire history into consideration, then assigned subjective weights to each factor according to their sensitivity to fire or their fire-inducing capability. By remote sensing and GIS, vegetation information layer were gotten from Landsat TM image and DEM with a scale of 1:50000 was abstracted from the digital scanned relief map. Topography info. (elevation, slope, aspect) layers could be gotten after that. A climate resource databank that contained the data from the stations of Lushan Mountain and other nearby 7 stations was built up and extrapolated through the way of grid extrapolation in order to make the distribution map of climate resource. Finally synthetical district division maps were made by weighing and integrating all the single factor special layers,and the study area were divided into three forest fire danger district, include special fire danger district, I-fire danger district and II-fire danger district. It could be used as a basis for developing a forest fire prevention system, preparing the annual investment plan, allocating reasonably the investment of fire prevention, developing the program of forest fire prevention and handle, setting up forest fire brigade, leaders' decisions on forest fire prevention work.

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 [Psaltriparus minimus]). We detected mixed results for the spotted towhee (Pipilo maculatus), which increased in burned chaparral and declined in burned coastal sage scrub within the low-elevation site. We suggest that the observed responses of birds to these fires may be attributed to: (1) the availability of nearby unburned refugia, (2) the continued suitability of post-fire vegetation at the study sites, and (3) the generally high mobility of this taxon.

Impact air quality by wildfire and agricultural fire in Mexico city 2015

NASA Astrophysics Data System (ADS)

Mendoza Campos, Alejandra; Agustín García Reynoso, José; Castro Romero, Telma Gloria; Carbajal Pérez, José Noel; Mar Morales, Bertha Eugenia; Gerardo Ruiz Suárez, Luis

2016-04-01

A forest fire is a large-scale process natural combustion where different types of flora and fauna of different sizes and ages are consumed. Consequently, forest fires are a potential source of large amounts of air pollutants that must be considered when trying to relate emissions to the air quality in neighboring cities of forest areas as in the Valley of Mexico. The size, intensity and occurrence of a forest fire directly dependent variables such as weather conditions, topography, vegetation type and its moisture content and the mass of fuel per hectare. An agricultural fire is a controlled combustion, which occurred a negligence can get out of control and increase the burned area or the possibly become a wildfire. Once a fire starts, the dry combustible material is consumed first. If the energy release is large and of sufficient duration, drying green material occurs live, with subsequent burning it. Under proper fuel and environmental conditions, this process can start a chain reaction. These events occur mainly in the dry season. Forest fires and agriculture fires contribute directly in the increase of carbon dioxide (CO2) into the atmosphere; The main pollutants emitted to the atmosphere by a wildfire are the PM10, PM2.5, NOx and VOC's, the consequences have by fire are deforestation, soil erosion or change of structure and composition of forests (Villers, 2006), also it affects ecosystems and the health of the population. In this study the impact of air quality for the emissions of particulate matter less than ten microns PM10, by wildfire and agricultural fire occurred on the same day and same place, the study was evaluated in Mexico City the Delegation Milpa Alta in the community of San Lorenzo Tlacoyucan, the fire occurred on 3rd March, 2015, the wildfire duration 12 hours consuming 32 hectares of oak forest and the agricultural fire duration 6 hours consumed 16 hectares of corn. To evaluate the impact of air quality the WRF-Chem, WRF-Fire and METv3 models were used, four scenarios were made, in the first forest fire emissions were included, in the second agricultural fire emissions were included, the third was the difference between agricultural burning and forest fire and the last stage model without fire emissions. In making the interpolation of the modeled scenarios forest and agricultural fires the impact of air quality in the Valley of Mexico was obtained by increasing the concentration of particles smaller than ten micrometers PM10, with the results of the modeling are obtained that the PM10 concentration is ten times higher in the wildfire regarding agricultural fire. By making interpolation between this difference and considering the fire scenario without emissions by that date, a maximum PM10 concentration was 170μg /m3 during the hours of the fires, which exceeds the Mexican standard NOM-025-SSA1-2014 that provides that the maximum allowable limit of exposure to particulate matter less than ten microns is 75μg/m3 on average 24 hours, forest and agricultural fires have an impact of 226% in the PM10 air quality affecting ecosystems and human health

Analysis of historical forest fire regime in Madrid region (1984-2010) and its relation with land-use/land-cover changes

NASA Astrophysics Data System (ADS)

Gómez-Nieto, Israel; Martín, María del Pilar; Salas, Francisco Javier; Gallardo, Marta

2013-04-01

Understanding the interaction between natural and socio-economic factors that determine fire regime is essential to make accurate projections and impact assessments. However, this requires having accurate historical, systematic, homogeneous and spatially explicit information on fire occurrence. Fire databases usually have serious limitations in this regard; therefore other sources of information, such as remote sensing, have emerged as alternatives to generate optimal fire maps on various spatial and temporal scales. Several national and international projects work in order to generate information to study the factors that determine the current fire regime and its future evolution. This work is included in the framework of the project "Forest fires under climate, social and economic Changes in Europe, the Mediterranean and other fire-affected areas of the World" (FUME http://www.fumeproject.eu), which aims to study the changes and factors related to fire regimes through time to determine the potential impacts on vegetation in Mediterranean regions and concrete steps to address future risk scenarios. We analyzed the changes in the fire regime in Madrid region (Spain) in the past three decades (1984-2010) and its relation to land use changes. We identified and mapped fires that have occurred in the region during those years using Landsat satellite images by combining digital techniques and visual analysis. The results show a clear cyclical behaviour of the fire, with years of high incidence (as 1985, 2000 and 2003, highlighted by the number of fires and the area concerned, over 2000 ha) followed by another with a clear occurrence decrease. At the same time, we analyzed the land use changes that have occurred in Madrid region between the early 80s and mid-2000s using as reference the CORINE Land-cover maps (1990, 2000 and 2006) and the Vegetation and Land Use map of the Community of Madrid, 1982. We studied the relationship between fire regimes and observed land-use and land-cover changes in the periods analyzed, it was determined that between years 1984 and 2006 most of the burned area remained pre-fire cover type (above 80% of the area). However, in areas that experienced change, the most important transitions were recorded in wooded areas, especially conifers, which became shrubs or sparsely vegetated areas, followed by non-irrigated crops, which were replaced by grasslands or industrial areas, and sparse vegetation which changed to shrubs. Finally, the analysis of land-use changes over burned areas situated shrubland as the most favored type of cover, either as a result of a vegetative degradation process after intense burning of wooded areas, especially conifers, or as stage of natural increase in areas previously covered by sparsely vegetation.

Spatial and Temporal Variability and Trends in 2001-2016 Global Fire Activity

NASA Astrophysics Data System (ADS)

Earl, Nick; Simmonds, Ian

2018-03-01

Fire regimes across the globe have great spatial and temporal variability, and these are influence by many factors including anthropogenic management, climate, and vegetation types. Here we utilize the satellite-based "active fire" product, from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors, to statistically analyze variability and trends in fire activity from the global to regional scales. We split up the regions by economic development, region/geographical land use, clusters of fire-abundant areas, or by religious/cultural influence. Weekly cycle tests are conducted to highlight and quantify part of the anthropogenic influence on fire regime across the world. We find that there is a strong statistically significant decline in 2001-2016 active fires globally linked to an increase in net primary productivity observed in northern Africa, along with global agricultural expansion and intensification, which generally reduces fire activity. There are high levels of variability, however. The large-scale regions exhibit either little change or decreasing in fire activity except for strong increasing trends in India and China, where rapid population increase is occurring, leading to agricultural intensification and increased crop residue burning. Variability in Canada has been linked to a warming global climate leading to a longer growing season and higher fuel loads. Areas with a strong weekly cycle give a good indication of where fire management is being applied most extensively, for example, the United States, where few areas retain a natural fire regime.

An evaluation of the relative fire hazards of jet A and jet B for commercial flight

NASA Technical Reports Server (NTRS)

Hibbard, R. R.; Hacker, P. T.

1973-01-01

The relative fire hazards of Jet A and Jet B aircraft fuels are evaluated. The evaluation is based on a consideration of the presence of and/or the generation of flammable mixtures in fuel systems, the ignition characteristics, and the flame propagation rates for the two fuel types. Three distinct aircraft operating regimes where fuel type may be a factor in fire hazards are considered. These are: (1) ground handling and refueling, (2) flight, and (3) crash. The evaluation indicates that the overall fire hazards for Jet A are less than for Jet B fuel.

Acute toxicity of fire-retardant and foam-suppressant chemicals to early life stages of chinook salmon (Oncorhynchus tshawytscha)

USGS Publications Warehouse

Buhl, Kevin J.; Hamilton, Steven J.

1998-01-01

Laboratorys studies were conducted to determine the acute toxicity of three fire retardants (Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F), and two fire-suppressant foams (Phos-Chek WD-881 and Ansul Silv-Ex) to early life stages of chinook salmon, Oncorhynchus tshawytscha, in hard and soft water. Regardless of water type, swim-up fry and juveniles (60 and 90 d posthatch) exhibited similar sensitivities to each chemical and these life stages were more sensitive than eyed eggs. Foam suppressants were more toxic to each life stage than the fire retardants in both water types. The descending rank order of toxicity for these chemicals tested with swim-up fry and juveniles (range of 96-h median lethal concentrations [LC50s]) was Phos-Chek WD-881 (7–13 mg/L) > Ansul Silv-Ex (11–22 mg/L) > Phos-Chek D75-F (218–305 mg/L) > Fire-Trol GTS-R (218–412 mg/L) > Fire-Trol LCG-R (685–1,195 mg/L). Water type had a minor effect on the toxicity of these chemicals. Comparison of acute toxicity values with recommended application concentrations indicates that accidental inputs of these chemicals into stream environments would require substantial dilution (237- to 1,429-fold) to reach concentrations equivalent to their 96-h LC50s.

Fire regimes of quaking aspen in the Mountain West

USGS Publications Warehouse

Shinneman, Douglas J.; Baker, William L.; Rogers, Paul C.; Kulakowski, Dominik

2013-01-01

Quaking aspen (Populus tremuloides Michx.) is the most widespread tree species in North America, and it is found throughout much of the Mountain West (MW) across a broad range of bioclimatic regions. Aspen typically regenerates asexually and prolifically after fire, and due to its seral status in many western conifer forests, aspen is often considered dependent upon disturbance for persistence. In many landscapes, historical evidence for post-fire aspen establishment is clear, and following extended fire-free periods senescing or declining aspen overstories sometimes lack adequate regeneration and are succeeding to conifers. However, aspen also forms relatively stable stands that contain little or no evidence of historical fire. In fact, aspen woodlands range from highly fire-dependent, seral communities to relatively stable, self-replacing, non-seral communities that do not require fire for persistence. Given the broad geographic distribution of aspen, fire regimes in these forests likely co-vary spatially with changing community composition, landscape setting, and climate, and temporally with land use and climate – but relatively few studies have explicitly focused on these important spatiotemporal variations. Here we reviewed the literature to summarize aspen fire regimes in the western US and highlight knowledge gaps. We found that only about one-fourth of the 46 research papers assessed for this review could be considered fire history studies (in which mean fire intervals were calculated), and all but one of these were based primarily on data from fire-scarred conifers. Nearly half of the studies reported at least some evidence of persistent aspen in the absence of fire. We also found that large portions of the MW have had little or no aspen fire history research. As a result of this review, we put forth a classification framework for aspen that is defined by key fire regime parameters (fire severity and probability), and that reflects underlying biophysical settings and correlated aspen functional types. We propose the following aspen fire regime types: (1) fire-independent, stable aspen; (2) fire-influenced, stable aspen; (3) fire-dependent, seral, conifer-aspen mix; (4) fire-dependent, seral, montane aspen-conifer; and (5) fire-dependent, seral, subalpine aspen-conifer. Closing research gaps and validating our proposed aspen fire regime classification will likely require additional site-specific research, enhanced dendrochronology techniques, charcoal and pollen record analysis, spatially-explicit modeling, and other techniques. We hope to encourage development of site-appropriate disturbance ecology characterizations, in order to aid efforts to manage and restore aspen communities and to diagnose key factors contributing to changes in aspen.

Linking Satellite-Derived Fire Counts to Satellite-Derived Weather Data in Fire Prediction Models to Forecast Extreme Fires in Siberia

NASA Astrophysics Data System (ADS)

Westberg, David; Soja, Amber; Stackhouse, Paul, Jr.

2010-05-01

Fire is the dominant disturbance that precipitates ecosystem change in boreal regions, and fire is largely under the control of weather and climate. Boreal systems contain the largest pool of terrestrial carbon, and Russia holds 2/3 of the global boreal forests. Fire frequency, fire severity, area burned and fire season length are predicted to increase in boreal regions under climate change scenarios. Meteorological parameters influence fire danger and fire is a catalyst for ecosystem change. Therefore to predict fire weather and ecosystem change, we must understand the factors that influence fire regimes and at what scale these are viable. Our data consists of NASA Langley Research Center (LaRC)-derived fire weather indices (FWI) and National Climatic Data Center (NCDC) surface station-derived FWI on a domain from 50°N-80°N latitude and 70°E-170°W longitude and the fire season from April through October for the years of 1999, 2002, and 2004. Both of these are calculated using the Canadian Forest Service (CFS) FWI, which is based on local noon surface-level air temperature, relative humidity, wind speed, and daily (noon-noon) rainfall. The large-scale (1°) LaRC product uses NASA Goddard Earth Observing System version 4 (GEOS-4) reanalysis and NASA Global Precipitation Climatology Project (GEOS-4/GPCP) data to calculate FWI. CFS Natural Resources Canada uses Geographic Information Systems (GIS) to interpolate NCDC station data and calculate FWI. We compare the LaRC GEOS- 4/GPCP FWI and CFS NCDC FWI based on their fraction of 1° grid boxes that contain satellite-derived fire counts and area burned to the domain total number of 1° grid boxes with a common FWI category (very low to extreme). These are separated by International Geosphere-Biosphere Programme (IGBP) 1°x1° resolution vegetation types to determine and compare fire regimes in each FWI/ecosystem class and to estimate the fraction of each of the 18 IGBP ecosystems burned, which are dependent on the FWI. On days with fire counts, the domain total of 1°x1° grid boxes with and without daily fire counts and area burned are totaled. The fraction of 1° grid boxes with fire counts and area burned to the total number of 1° grid boxes having common FWI category and vegetation type are accumulated, and a daily mean for the burning season is calculated. The mean fire counts and mean area burned plots appear to be well related. The ultimate goal of this research is to assess the viability of large-scale (1°) data to be used to assess fire weather danger and fire regimes, so these data can be confidently used to predict future fire regimes using large-scale fire weather data. Specifically, we related large-scale fire weather, area burned, and the amount of fire-induced ecosystem change. Both the LaRC and CFS FWI showed gradual linear increase in fraction of grid boxes with fire counts and area burned with increasing FWI category, with an exponential increase in the higher FWI categories in some cases, for the majority of the vegetation types. Our analysis shows a direct correlation between increased fire activity and increased FWI, independent of time or the severity of the fire season. During normal and extreme fire seasons, we noticed the fraction of fire counts and area burned per 1° grid box increased with increasing FWI rating. Given this analysis, we are confident large-scale weather and climate data, in this case from the GEOS-4 reanalysis and the GPCP data sets, can be used to accurately assess future fire potential. This increases confidence in the ability of large-scale IPCC weather and climate scenarios to predict future fire regimes in boreal regions.

Modeling the Effects of Fire Frequency and Severity on Forests in the Northwestern United States

USGS Publications Warehouse

Busing, Richard T.; Solomon, Allen M.

2006-01-01

This study used a model of forest dynamics (FORCLIM) and actual forest survey data to demonstrate the effects of various fire regimes on different forest types in the Pacific Northwest. We examined forests in eight ecoregions ranging from wet coastal forests dominated by Pseudotsuga menziesii and other tall conifers to dry interior forests dominated by Pinus ponderosa. Fire effects simulated as elevated mortality of trees based on their species and size did alter forest structure and species composition. Low frequency fires characteristic of wetter forests (return interval >200 yr) had minor effects on composition. When fires were severe, they tended to reduce total basal area with little regard to species differences. High frequency fires characteristic of drier forests (return interval <30 yr) had major effects on species composition and on total basal area. Typically, they caused substantial reductions in total basal area and shifts in dominance toward highly fire tolerant species. With the addition of fire, simulated basal areas averaged across ecoregions were reduced to levels approximating observed basal areas.

At the nexus of fire, water and society

USGS Publications Warehouse

Martin, Deborah

2016-01-01

The societal risks of water scarcity and water-quality impairment have received considerable attention, evidenced by recent analyses of these topics by the 2030 Water Resources Group, the United Nations and the World Economic Forum. What are the effects of fire on the predicted water scarcity and declines in water quality? Drinking water supplies for humans, the emphasis of this exploration, are derived from several land cover types, including forests, grasslands and peatlands, which are vulnerable to fire. In the last two decades, fires have affected the water supply catchments of Denver (CO) and other southwestern US cities, and four major Australian cities including Sydney, Canberra, Adelaide and Melbourne. In the same time period, several, though not all, national, regional and global water assessments have included fire in evaluations of the risks that affect water supplies. The objective of this discussion is to explore the nexus of fire, water and society with the hope that a more explicit understanding of fire effects on water supplies will encourage the incorporation of fire into future assessments of water supplies, into the pyrogeography conceptual framework and into planning efforts directed at water resiliency.

Micromorphological characteristics of sandy forest soils recently impacted by wildfires in Russia

NASA Astrophysics Data System (ADS)

Maksimova, Ekaterina; Abakumov, Evgeny

2017-04-01

Two fire-affected soils were studied using micromorphological methods. The objective of the paper is to assess and compare fire effects on the micropedological organisation of soils in a forest-steppe zone of central Russia (Volga Basin, Togliatti city). Samples were collected in the green zone of Togliatti city. The results showed that both soils were rich in quartz and feldspar. Mica was highly present in soils affected by surface fires, while calcium carbonates were identified in the soils affected by crown fires. The type of plasma is humus-clay, but the soil assemblage is plasma-silt with a prevalence of silt. Angular and subangular grains are the most dominant soil particulates. No evidence of intensive weathering was detected. There was a decrease in the porosity of soils affected by fires as a consequence of soil pores filled with ash and charcoal.

Assessment of fire effects based on Forest Inventory and Analysis data and a long-term fire mapping data set

Treesearch

John D. Shaw; Sara A. Goeking; James Menlove; Charles E. Werstak

2017-01-01

Integration of Forest Inventory and Analysis (FIA) plot data with Monitoring Trends in Burn Severity (MTBS) data can provide new information about fire effects on forests. This integration allowed broad-scale assessment of the cover types burned in large fires, the relationship between prefire stand conditions and fire severity, and postfire stand conditions. Of the 42...

Prioritizing forest fuels treatments based on the probability of high-severity fire restores adaptive capacity in Sierran forests

Treesearch

Daniel J. Krofcheck; Matthew D. Hurteau; Robert M. Scheller; E. Louise Loudermilk

2017-01-01

In frequent fire forests of the western United States, a legacy of fire suppression coupled with increases in fire weather severity have altered fire regimes and vegetation dynamics. When coupled with projected climate change, these conditions have the potential to lead to vegetation type change and altered carbon (C) dynamics. In the Sierra Nevada, fuels...

Fires at storage sites of organic materials, waste fuels and recyclables.

PubMed

Ibrahim, Muhammad Asim; Alriksson, Stina; Kaczala, Fabio; Hogland, William

2013-09-01

During the last decade, the European Union has enforced the diversion of organic wastes and recyclables to waste management companies operating incineration plants, composting plants and recycling units instead of landfills. The temporary storage sites have been established as a buffer against fluctuations in energy demand throughout the year. Materials also need to be stored at temporary storage sites before recovery and recycling. However, regulations governing waste fuel storage and handling have not yet been developed, and, as a result, companies have engaged in risky practices that have resulted in a high number of fire incidents. In this study, a questionnaire survey was distributed to 249 of the 400 members of Avfall Sverige (Swedish Waste Management Association), which represents the waste management of 95% of the Swedish population. Information regarding 122 storage facilities owned by 69 companies was obtained; these facilities were responsible for the storage of 47% of the total treated waste (incineration + digestion + composting) in 2010 in Sweden. To identify factors related to fire frequency, the questionnaire covered the amounts of material handled and burnt per year, financial losses due to fires, storage duration, storage method and types of waste. The results show that 217 fire incidents corresponded to 170 kilotonnes of material burnt and cumulative losses of 49 million SEK (€4.3 million). Fire frequency and amount of material burnt per fire was found to be dependent upon type of management group (waste operator). Moreover, a correlation was found between fire frequency and material recycled during past years. Further investigations of financial aspects and externalities of fire incidents are recommended.

46 CFR 62.35-15 - Fire safety.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Requirements for Specific Types of Automated Vital Systems § 62.35-15 Fire safety. (a) All required fire pump remote control locations must include the controls necessary to charge the firemain and— (1) A firemain...

46 CFR 62.35-15 - Fire safety.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Requirements for Specific Types of Automated Vital Systems § 62.35-15 Fire safety. (a) All required fire pump remote control locations must include the controls necessary to charge the firemain and— (1) A firemain...

46 CFR 62.35-15 - Fire safety.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Requirements for Specific Types of Automated Vital Systems § 62.35-15 Fire safety. (a) All required fire pump remote control locations must include the controls necessary to charge the firemain and— (1) A firemain...

46 CFR 161.002-2 - Types of fire-protective systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... systems will be considered to consist of normal and emergency power supplies, a fire detecting control... subpart, manual fire alarm systems will be considered to consist of normal and emergency power supplies, a...

46 CFR 161.002-2 - Types of fire-protective systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... systems will be considered to consist of normal and emergency power supplies, a fire detecting control... subpart, manual fire alarm systems will be considered to consist of normal and emergency power supplies, a...

Export of solids and nutrients from burnt areas: effects of fire severity and forest type

NASA Astrophysics Data System (ADS)

Abrantes, Nelson; Morais, Inês; Silva, Vera; Malvar, Mauxa C.; Prats, Sérgio; Coelho, Celeste; Keizer, Jan J.

2015-04-01

In the last few decades, the number of wildfires has markedly increased in Mediterranean Europe, including Portugal. Besides a range of direct impacts, wildfires can significantly alter the geomorphological and hydrological processes during a period commonly referred to as the "window-of-disturbance". It is now increasingly recognized that these indirect wildfire effects depend strongly on fire severity, i.e. the heating-induced changes in vegetation and litter cover as well as in topsoil properties such as infiltration capacity, aggregate stability and soil water repellency. Nonetheless, the exact role of fire severity in post-fire hydrological and erosion processes is still poorly quantified in many parts of the world, including Portugal. Another important gap in fire-related research stills to be the impacts of wildfire on soil fertility losses, in particular through erosion by runoff. Both research gaps were addressed in this study, following a wildfire that took place in July 2013 in Talhadas (Sever do Vouga, Aveiro) and burnt circa 815 ha. In the burnt area and the surrounding unburnt areas, six study sites were selected and, immediately after the fire, instrumented with slope-scale runoff plots. Two of the sites were long-unburnt, two were burnt at low severity and the other two were burnt at high severity; for all of them one being covered by a Eucalyptus globulus plantation and the other by a Pinus pinaster plantation. Following the instrumentation of the sites, runoff was measured at 1- to 2-weekly intervals and, whenever possible, runoff samples were collected for subsequent analysis in the laboratory with respect to total suspended sediments content and total nitrogen and total phosphorus concentrations. The results obtained in this study showed that the severity of the fire played a more important role in the loss of nutrients and solids than the type of vegetation. While the occurrence of fire markedly increased soil (fertility) losses, this effect was much stronger following a high-severity than low-severity fire. In the case of the pine slope, this effect of fire severity could be attributed to post-fire pine needle cast, with pine needles being scorched by the low-severity fire and being combusted in the high-severity fire. Looking at the temporal evolution, for both pine and eucalyptus slopes, significant exportations of solids as well nutrients were still found 10 months after the fire occurrence (May 2014) . This study highlight the importance of wildfire as a driver for the soil and fertility loss with consequent/potential impacts on surface water quality.

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

Wildfires have a wide diversity of impacts on landscape which, in turn, depend on the interaction of fire regimes (e.g. intensity, extent, frequency) and the response of vegetation to them in short and long-terms. The increase in erosion rates and the loss of nutrients by runoff in the first months following the fire are among the major impacts of wildfires. A minimum of 30% of vegetation cover is enough to protect soils against erosion but vegetation may require a long period to reach this threshold after severe fires. Since erosion risk is strongly linked to vegetation recovery rates, post-fire vegetation monitoring becomes crucial in land management. Fire regimes in the Mediterranean have been changing in the past decades due to modifications in both socio-economic and climate patterns. Although many vegetation species in Mediterranean ecosystems are adapted to wildfires, changes in fire regime characteristics affect the ability of ecosystems to recover to their previous state. In Spain, fire is an important driver of changes in landscape composition, leading to dominance of shrubland following fire and to a major decrease of pine woodlands (Viedma et al., 2006). Remote sensing is a powerful tool in land management, allowing vegetation monitoring on large spatial scales for relatively long periods of time. In order to assess vegetation dynamics, monthly NDVI data from 1998-2009 from SPOT/VEGETATION at 1km spatial resolution over the Iberian Peninsula were used. This work focuses on 2005 fire season in Spain, which registered the highest amount of burnt area since 1994, with more than 188000 ha burnt. Burnt scars in this fire season were identified by cluster analysis. Post-fire vegetation recovery was assessed based on the monoparametric model developed by Gouveia et al. (2010) that was applied to four large scars located in different geographical settings with different land cover characteristics. While the two northern regions presented fast recovery, in the 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.

Probabilistic discrimination between liquid rainfall events, hailstorms, biomass burning and industrial fires from C-Band Radar Polarimetric Variables

NASA Astrophysics Data System (ADS)

Valencia, J. M.; Sepúlveda, J.; Hoyos, C.; Herrera, L.

2017-12-01

Characterization and identification of fire and hailstorm events using weather radar data in a tropical complex topography region is an important task in risk management and agriculture. Polarimetric variables from a C-Band Dual polarization weather radar have potential uses in particle classification, due to the relationship their sensitivity to shape, spatial orientation, size and fall behavior of particles. In this sense, three forest fires and two chemical fires were identified for the Áburra Valley regions. Measurements were compared between each fire event type and with typical data radar retrievals for liquid precipitation events. Results of this analysis show different probability density functions for each type of event according to the particles present in them. This is very important and useful result for early warning systems to avoid precipitation false alarms during fire events within the study region, as well as for the early detection of fires using radar retrievals in remote cases. The comparative methodology is extended to hailstorm cases. Complementary sensors like laser precipitation sensors (LPM) disdrometers and meteorological stations were used to select dates of solid precipitation occurrence. Then, in this dates weather radar data variables were taken in pixels surrounding the stations and solid precipitation polar values were statistically compared with liquid precipitation values. Spectrum precipitation measured by LPM disdrometer helps to define typical features like particles number, fall velocities and diameters for both precipitation types. In addition, to achieve a complete hailstorm characterization, other meteorological variables were analyzed: wind field from meteorological stations and radar wind profiler, profiling data from Micro Rain Radar (MRR), and thermodynamic data from a microwave radiometer.

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.

Human and biophysical influences on fire occurrence in the United States

USGS Publications Warehouse

Hawbaker, Todd J.; Radeloff, Volker C.; Stewart, Susan I.; Hammer, Roger B.; Keuler, Nicholas S.; Clayton, Murray K.

2013-01-01

National-scale analyses of fire occurrence are needed to prioritize fire policy and management activities across the United States. However, the drivers of national-scale patterns of fire occurrence are not well understood, and how the relative importance of human or biophysical factors varies across the country is unclear. Our research goal was to model the drivers of fire occurrence within ecoregions across the conterminous United States. We used generalized linear models to compare the relative influence of human, vegetation, climate, and topographic variables on fire occurrence in the United States, as measured by MODIS active fire detections collected between 2000 and 2006. We constructed models for all fires and for large fires only and generated predictive maps to quantify fire occurrence probabilities. Areas with high fire occurrence probabilities were widespread in the Southeast, and localized in the Mountain West, particularly in southern California, Arizona, and New Mexico. Probabilities for large-fire occurrence were generally lower, but hot spots existed in the western and south-central United States The probability of fire occurrence is a critical component of fire risk assessments, in addition to vegetation type, fire behavior, and the values at risk. Many of the hot spots we identified have extensive development in the wildland–urban interface and are near large metropolitan areas. Our results demonstrated that human variables were important predictors of both all fires and large fires and frequently exhibited nonlinear relationships. However, vegetation, climate, and topography were also significant variables in most ecoregions. If recent housing growth trends and fire occurrence patterns continue, these areas will continue to challenge policies and management efforts seeking to balance the risks generated by wildfires with the ecological benefits of fire.

Wildfire and forest disease interaction lead to greater loss of soil nutrients and carbon.

PubMed

Cobb, Richard C; Meentemeyer, Ross K; Rizzo, David M

2016-09-01

Fire and forest disease have significant ecological impacts, but the interactions of these two disturbances are rarely studied. We measured soil C, N, Ca, P, and pH in forests of the Big Sur region of California impacted by the exotic pathogen Phytophthora ramorum, cause of sudden oak death, and the 2008 Basin wildfire complex. In Big Sur, overstory tree mortality following P. ramorum invasion has been extensive in redwood and mixed evergreen forests, where the pathogen kills true oaks and tanoak (Notholithocarpus densiflorus). Sampling was conducted across a full-factorial combination of disease/no disease and burned/unburned conditions in both forest types. Forest floor organic matter and associated nutrients were greater in unburned redwood compared to unburned mixed evergreen forests. Post-fire element pools were similar between forest types, but lower in burned-invaded compared to burned-uninvaded plots. We found evidence disease-generated fuels led to increased loss of forest floor C, N, Ca, and P. The same effects were associated with lower %C and higher PO4-P in the mineral soil. Fire-disease interactions were linear functions of pre-fire host mortality which was similar between the forest types. Our analysis suggests that these effects increased forest floor C loss by as much as 24.4 and 21.3 % in redwood and mixed evergreen forests, respectively, with similar maximum losses for the other forest floor elements. Accumulation of sudden oak death generated fuels has potential to increase fire-related loss of soil nutrients at the region-scale of this disease and similar patterns are likely in other forests, where fire and disease overlap.

Evaluation of weapons' combustion products in armored vehicles. Final report, 30 September 1986-14 December 1988

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

Menzies, K.T.; Randel, M.A.; Quill, A.L.

1989-01-01

The U.S. Army Biomedical Research and Development Laboratory defined an extensive research program to address the generation of potentially toxic propellant combustion products in crew compartments of armored vehicles during weapons firing. The major objectives of the research were: (1) to determine the presence and concentration of propellant combustion products, (2) to determine potential crew exposure to these combustion products, and (3) to assess the efficacy of field monitoring in armored vehicles. To achieve these goals, air monitoring was conducted in selected armored vehicle types, i.e., M109, M60, M3, M1, at several Army installations. Auxiliary information concerning the specific munitionsmore » fired and the Training and Doctrine Command (TRADOC) or Forces Command (FORSCOM) firing scenarios was collected so that a comparison of pollutant concentrations generated by specific weapons both within vehicle types and between vehicle types could be made.« less

The potential benefit of a home fire safety intervention during emergency medical services calls.

PubMed

Pirrallo, R G; Rubin, J M; Murawsky, G A

1998-03-01

To determine how often house fires occur at 1- and 2-family dwellings visited previously by emergency medical services (EMS) personnel and whether these visits were missed opportunities for a point-of-contact home fire safety intervention. A retrospective, consecutive, case series analysis of all Milwaukee Fire Department alarm responses during 1994 was performed. Measurements included date of service, type of response, property type, dollar loss estimate, number of injuries and fatalities, cause of alarm, and presence of an operational smoke detector. Descriptive, chi2, and relative risk statistics were used to describe the relationship between EMS responses and fire responses at 1- and 2-family dwellings. The Milwaukee Fire Department dispatched 94,378 requests for service to 43,556 addresses. 16,150 addresses generated multiple requests; 7.2% (1,162/16,150) were for an "alarm of fire" response [relative risk 1.83 (95% CI: 1.69-1.99) for addresses with multiple requests vs those with a single request for service]. Most [62% (721/1,162)] of the addresses were visited by EMS personnel prior to the alarm; 28% (205/721) were 1- and 2-family dwellings. A mean of 1.8 (376/205) EMS responses occurred prior to the "alarm of fire" response; 121 addresses received 1 response, 46 received 2, 18 received 3, and 20 received > or = 4 responses. Of 169 addresses with complete data, there was a total fire dollar loss of $1,963,020 (1994) along with 32 injuries and 0 fatalities. While 47% (80/169) of the 1- and 2-family dwellings had a smoke detector present, only 17% (29/169) of the dwellings had an operational smoke detector. A point-of-contact home fire safety intervention appears of potential benefit for frequent users of EMS care. Determination of the presence of an operational smoke detector in 1- and 2-family dwellings may be a useful injury prevention act during such EMS calls.

Burning phylogenies: fire, molecular evolutionary rates, and diversification.

PubMed

Verdú, Miguel; Pausas, Juli G; Segarra-Moragues, José Gabriel; Ojeda, Fernando

2007-09-01

Mediterranean-type ecosystems are among the most remarkable plant biodiversity "hot spots" on the earth, and fire has traditionally been invoked as one of the evolutionary forces explaining this exceptional diversity. In these ecosystems, adult plants of some species are able to survive after fire (resprouters), whereas in other species fire kills the adults and populations are only maintained by an effective post-fire recruitment (seeders). Seeders tend to have shorter generation times than resprouters, particularly under short fire return intervals, thus potentially increasing their molecular evolutionary rates and, ultimately, their diversification. We explored whether seeder lineages actually have higher rates of molecular evolution and diversification than resprouters. Molecular evolutionary rates in different DNA regions were compared in 45 phylogenetically paired congeneric taxa from fire-prone Mediterranean-type ecosystems with contrasting seeder and resprouter life histories. Differential diversification was analyzed with both topological and chronological approaches in five genera (Banksia, Daviesia, Lachnaea, Leucadendron, and Thamnochortus) from two fire-prone regions (Australia and South Africa). We found that seeders had neither higher molecular rates nor higher diversification than resprouters. Such lack of differences in molecular rates between seeders and resprouters-which did not agree with theoretical predictions-may occur if (1) the timing of the switch from seeding to resprouting (or vice versa) occurs near the branch tip, so that most of the branch length evolves under the opposite life-history form; (2) resprouters suffer more somatic mutations and therefore counterbalancing the replication-induced mutations of seeders; and (3) the rate of mutations is not related to shorter generation times because plants do not undergo determinate germ-line replication. The absence of differential diversification is to be expected if seeders and resprouters do not differ from each other in their molecular evolutionary rate, which is the fuel for speciation. Although other factors such as the formation of isolated populations may trigger diversification, we can conclude that fire acting as a throttle for diversification is by no means the rule in fire-prone ecosystems.

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.

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.

Assessment of the Utility of the Advanced Himawari Imager to Detect Active Fire Over Australia

NASA Astrophysics Data System (ADS)

Hally, B.; Wallace, L.; Reinke, K.; Jones, S.

2016-06-01

Wildfire detection and attribution is an issue of importance due to the socio-economic impact of fires in Australia. Early detection of fires allows emergency response agencies to make informed decisions in order to minimise loss of life and protect strategic resources in threatened areas. Until recently, the ability of land management authorities to accurately assess fire through satellite observations of Australia was limited to those made by polar orbiting satellites. The launch of the Japan Meteorological Agency (JMA) Himawari-8 satellite, with the 16-band Advanced Himawari Imager (AHI-8) onboard, in October 2014 presents a significant opportunity to improve the timeliness of satellite fire detection across Australia. The near real-time availability of images, at a ten minute frequency, may also provide contextual information (background temperature) leading to improvements in the assessment of fire characteristics. This paper investigates the application of the high frequency observation data supplied by this sensor for fire detection and attribution. As AHI-8 is a new sensor we have performed an analysis of the noise characteristics of the two spectral bands used for fire attribution across various land use types which occur in Australia. Using this information we have adapted existing algorithms, based upon least squares error minimisation and Kalman filtering, which utilise high frequency observations of surface temperature to detect and attribute fire. The fire detection and attribution information provided by these algorithms is then compared to existing satellite based fire products as well as in-situ information provided by land management agencies. These comparisons were made Australia-wide for an entire fire season - including many significant fire events (wildfires and prescribed burns). Preliminary detection results suggest that these methods for fire detection perform comparably to existing fire products and fire incident reporting from relevant fire authorities but with the advantage of being near-real time. Issues remain for detection due to cloud and smoke obscuration, along with validation of the attribution of fire characteristics using these algorithms.

Predictions of fire behavior and resistance to control: for use with photo series for the ponderosa pine type, ponderosa pine and associated species type, and lodgepole pine type.

Treesearch

Franklin R. Ward; David V. Sandberg

1981-01-01

This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the publication, "Photo Series for Quantifying Forest Residues in the Ponderosa Pine Type, Ponderosa Pine and Associated Species Type, Lodgepole Pine Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-052....

A comparison of visual and quantitative changes from rotational prescribed burning in old-growth stands of southwestern Ponderosa pine

Treesearch

S. M. Haase; S. S. Sackett

2008-01-01

Two long-term prescribed fire studies were established near Flagstaff, Arizona in 1976 and 1977. One of the sites, Chimney Spring, is located on a basalt soil type and had not received any natural fires for the previous 100 years. The other site, called Limestone Flats, located on a sedimentary soil type, has a similar fire-free period but received a sanitation cut to...

At the nexus of fire, water and society

PubMed Central

2016-01-01

The societal risks of water scarcity and water-quality impairment have received considerable attention, evidenced by recent analyses of these topics by the 2030 Water Resources Group, the United Nations and the World Economic Forum. What are the effects of fire on the predicted water scarcity and declines in water quality? Drinking water supplies for humans, the emphasis of this exploration, are derived from several land cover types, including forests, grasslands and peatlands, which are vulnerable to fire. In the last two decades, fires have affected the water supply catchments of Denver (CO) and other southwestern US cities, and four major Australian cities including Sydney, Canberra, Adelaide and Melbourne. In the same time period, several, though not all, national, regional and global water assessments have included fire in evaluations of the risks that affect water supplies. The objective of this discussion is to explore the nexus of fire, water and society with the hope that a more explicit understanding of fire effects on water supplies will encourage the incorporation of fire into future assessments of water supplies, into the pyrogeography conceptual framework and into planning efforts directed at water resiliency. This article is part of the themed issue ‘The interaction of fire and mankind’. PMID:27216505

Spatial and temporal selectivity patterns of fires in Attika, Greece from 1984 to 2015 delineated from Landsat time series satellite images

NASA Astrophysics Data System (ADS)

Stamos, Zoi; Koutsias, Nikos

2017-04-01

The aim of this study is to assess spatial and temporalfire selectivity patterns in the region of Attica - Greece from 1984 to 2015. Our work is implemented in two distinct phases: the first consists of the accurate delineation of the fire perimeter using satellite remote sensing technology, and the second consists of the application of suitable GIS supported analyses to develop thematic layers that optimally summarised the spatial and temporal information of fire occurrence. Fire perimeters of wildland fires occurred within the time window 1984-2015 were delineated from freely available Landsat images from USGS and ESA sources.More than three thousands satellite images were processed in order to extract fire perimeters and create maps of fire frequency and fire return interval. In total one thousand and one hundred twenty fire perimeters were recorded during this thirty years' period. Fire perimeters within each year of fire occurrence were compared against the available to burn under complete random processes to identify selectivity patterns over (i) CORINE land use/land cover, (ii) fire frequency and (iii) time since last firemaps. For example, non- irrigated arable lands, complex cultivation patterns and discontinuous urban fabrics are negative related with fires, while coniferous forests, sclerophyllous vegetation and transitional woodlands seem to be preferable by the fires. Additionally, it seems that fires prefer their old burnings (two and three times burned) and also places with different patterns of time since last fire depending on the time needed by the type of vegetation to recover and thus to re-burn.

46 CFR 52.25-15 - Fired thermal fluid heaters.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Fired thermal fluid heaters. 52.25-15 Section 52.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-15 Fired thermal fluid heaters. (a) Fired thermal fluid heaters shall be designed...

46 CFR 52.25-15 - Fired thermal fluid heaters.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Fired thermal fluid heaters. 52.25-15 Section 52.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-15 Fired thermal fluid heaters. (a) Fired thermal fluid heaters shall be designed...

46 CFR 52.25-15 - Fired thermal fluid heaters.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Fired thermal fluid heaters. 52.25-15 Section 52.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-15 Fired thermal fluid heaters. (a) Fired thermal fluid heaters shall be designed...

Steppe plant response to seasonal fire

Treesearch

Paulette L. Ford

2003-01-01

Fire is a natural grassland disturbance that affects a variety of ecosystem factors including nutrient cycling, species diversity, and population and community dynamics. Caution is warranted when interpreting the effects of fire on grasslands due to the variety of fire types (e.g. wildfire vs prescribed burn), season of occurrence, weather conditions, grassland uses (e...

Fire weather technology for fire agrometeorology operations

Treesearch

Francis Fujioka

2008-01-01

Even as the magnitude of wildfire problems increases globally, United Nations agencies are acting to mitigate the risk of wildfire disasters to members. Fire management organizations worldwide may vary considerably in operational scope, depending on the number and type of resources an organization manages. In any case, good fire weather information is vital. This paper...

Decadal time-scale monitoring of forest fires in Similipal Biosphere Reserve, India using remote sensing and GIS.

PubMed

Saranya, K R L; Reddy, C Sudhakar; Rao, P V V Prasada; Jha, C S

2014-05-01

Analyzing the spatial extent and distribution of forest fires is essential for sustainable forest resource management. There is no comprehensive data existing on forest fires on a regular basis in Biosphere Reserves of India. The present work have been carried out to locate and estimate the spatial extent of forest burnt areas using Resourcesat-1 data and fire frequency covering decadal fire events (2004-2013) in Similipal Biosphere Reserve. The anomalous quantity of forest burnt area was recorded during 2009 as 1,014.7 km(2). There was inconsistency in the fire susceptibility across the different vegetation types. The spatial analysis of burnt area shows that an area of 34.2 % of dry deciduous forests, followed by tree savannah, shrub savannah, and grasslands affected by fires in 2013. The analysis based on decadal time scale satellite data reveals that an area of 2,175.9 km(2) (59.6 % of total vegetation cover) has been affected by varied rate of frequency of forest fires. Fire density pattern indicates low count of burnt area patches in 2013 estimated at 1,017 and high count at 1,916 in 2004. An estimate of fire risk area over a decade identifies 12.2 km(2) is experiencing an annual fire damage. Summing the fire frequency data across the grids (each 1 km(2)) indicates 1,211 (26 %) grids are having very high disturbance regimes due to repeated fires in all the 10 years, followed by 711 grids in 9 years and 418 in 8 years and 382 in 7 years. The spatial database offers excellent opportunities to understand the ecological impact of fires on biodiversity and is helpful in formulating conservation action plans.

Western Spruce Budworm Outbreaks Did Not Increase Fire Risk over the Last Three Centuries: A Dendrochronological Analysis of Inter-Disturbance Synergism

PubMed Central

Flower, Aquila; G. Gavin, Daniel; Heyerdahl, Emily K.; Parsons, Russell A.; Cohn, Gregory M.

2014-01-01

Insect outbreaks are often assumed to increase the severity or probability of fire occurrence through increased fuel availability, while fires may in turn alter susceptibility of forests to subsequent insect outbreaks through changes in the spatial distribution of suitable host trees. However, little is actually known about the potential synergisms between these natural disturbances. Assessing inter-disturbance synergism is challenging due to the short length of historical records and the confounding influences of land use and climate changes on natural disturbance dynamics. We used dendrochronological methods to reconstruct defoliator outbreaks and fire occurrence at ten sites along a longitudinal transect running from central Oregon to western Montana. We assessed synergism between disturbance types, analyzed long-term changes in disturbance dynamics, and compared these disturbance histories with dendroclimatological moisture availability records to quantify the influence of moisture availability on disturbances. After approximately 1890, fires were largely absent and defoliator outbreaks became longer-lasting, more frequent, and more synchronous at our sites. Fires were more likely to occur during warm-dry years, while outbreaks were most likely to begin near the end of warm-dry periods. Our results show no discernible impact of defoliation events on subsequent fire risk. Any effect from the addition of fuels during defoliation events appears to be too small to detect given the overriding influence of climatic variability. We therefore propose that if there is any relationship between the two disturbances, it is a subtle synergistic relationship wherein climate determines the probability of occurrence of each disturbance type, and each disturbance type damps the severity, but does not alter the probability of occurrence, of the other disturbance type over long time scales. Although both disturbance types may increase in frequency or extent in response to future warming, our records show no precedent that western spruce budworm outbreaks will increase future fire risk. PMID:25526633

Western spruce budworm outbreaks did not increase fire risk over the last three centuries: a dendrochronological analysis of inter-disturbance synergism.

PubMed

Flower, Aquila; Gavin, Daniel G; Heyerdahl, Emily K; Parsons, Russell A; Cohn, Gregory M

2014-01-01

Insect outbreaks are often assumed to increase the severity or probability of fire occurrence through increased fuel availability, while fires may in turn alter susceptibility of forests to subsequent insect outbreaks through changes in the spatial distribution of suitable host trees. However, little is actually known about the potential synergisms between these natural disturbances. Assessing inter-disturbance synergism is challenging due to the short length of historical records and the confounding influences of land use and climate changes on natural disturbance dynamics. We used dendrochronological methods to reconstruct defoliator outbreaks and fire occurrence at ten sites along a longitudinal transect running from central Oregon to western Montana. We assessed synergism between disturbance types, analyzed long-term changes in disturbance dynamics, and compared these disturbance histories with dendroclimatological moisture availability records to quantify the influence of moisture availability on disturbances. After approximately 1890, fires were largely absent and defoliator outbreaks became longer-lasting, more frequent, and more synchronous at our sites. Fires were more likely to occur during warm-dry years, while outbreaks were most likely to begin near the end of warm-dry periods. Our results show no discernible impact of defoliation events on subsequent fire risk. Any effect from the addition of fuels during defoliation events appears to be too small to detect given the overriding influence of climatic variability. We therefore propose that if there is any relationship between the two disturbances, it is a subtle synergistic relationship wherein climate determines the probability of occurrence of each disturbance type, and each disturbance type damps the severity, but does not alter the probability of occurrence, of the other disturbance type over long time scales. Although both disturbance types may increase in frequency or extent in response to future warming, our records show no precedent that western spruce budworm outbreaks will increase future fire risk.

Investigating the association between weather conditions, calendar events and socio-economic patterns with trends in fire incidence: an Australian case study

NASA Astrophysics Data System (ADS)

Corcoran, Jonathan; Higgs, Gary; Rohde, David; Chhetri, Prem

2011-06-01

Fires in urban areas can cause significant economic, physical and psychological damage. Despite this, there has been a comparative lack of research into the spatial and temporal analysis of fire incidence in urban contexts. In this paper, we redress this gap through an exploration of the association of fire incidence to weather, calendar events and socio-economic characteristics in South-East Queensland, Australia using innovative technique termed the quad plot. Analysing trends in five fire incident types, including malicious false alarms (hoax calls), residential buildings, secondary (outdoor), vehicle and suspicious fires, results suggest that risk associated with all is greatly increased during school holidays and during long weekends. For all fire types the lowest risk of incidence was found to occur between one and six a.m. It was also found that there was a higher fire incidence in socially disadvantaged neighbourhoods and there was some evidence to suggest that there may be a compounding impact of high temperatures in such areas. We suggest that these findings may be used to guide the operations of fire services through spatial and temporal targeting to better utilise finite resources, help mitigate risk and reduce casualties.

TETRAMETHRIN AND DDT INHIBIT SPONTANEOUS FIRING IN CORTICAL NEURONAL NETWORKS

EPA Science Inventory

The insecticidal and neurotoxic effects of pyrethroids result from prolonged sodium channel inactivation, which causes alterations in neuronal firing and communication. Previously, we determined the relative potencies of 11 type I and type II pyrethroid insecticides using microel...

Fire Testing of Ethanol-Based Hand Cleaner

DOT National Transportation Integrated Search

1998-04-01

A variety of laboratory and full-scale fire tests were conducted on an ethanol-based gel-type hand cleaner currently used in commercial aircraft lavatories. The waterless-type hand cleaner has a relatively low flash point, raising concern over its fi...

Spatial temporal clustering for hotspot using kulldorff scan statistic method (KSS): A case in Riau Province

NASA Astrophysics Data System (ADS)

Hudjimartsu, S. A.; Djatna, T.; Ambarwari, A.; Apriliantono

2017-01-01

The forest fires in Indonesia occurs frequently in the dry season. Almost all the causes of forest fires are caused by the human activity itself. The impact of forest fires is the loss of biodiversity, pollution hazard and harm the economy of surrounding communities. To prevent fires required the method, one of them with spatial temporal clustering. Spatial temporal clustering formed grouping data so that the results of these groupings can be used as initial information on fire prevention. To analyze the fires, used hotspot data as early indicator of fire spot. Hotspot data consists of spatial and temporal dimensions can be processed using the Spatial Temporal Clustering with Kulldorff Scan Statistic (KSS). The result of this research is to the effectiveness of KSS method to cluster spatial hotspot in a case within Riau Province and produces two types of clusters, most cluster and secondary cluster. This cluster can be used as an early fire warning information.

Use of regionalisation approach to develop fire frequency curves for Victoria, Australia

NASA Astrophysics Data System (ADS)

Khastagir, Anirban; Jayasuriya, Niranjali; Bhuyian, Muhammed A.

2017-11-01

It is important to perform fire frequency analysis to obtain fire frequency curves (FFC) based on fire intensity at different parts of Victoria. In this paper fire frequency curves (FFCs) were derived based on forest fire danger index (FFDI). FFDI is a measure related to fire initiation, spreading speed and containment difficulty. The mean temperature (T), relative humidity (RH) and areal extent of open water (LC2) during summer months (Dec-Feb) were identified as the most important parameters for assessing the risk of occurrence of bushfire. Based on these parameters, Andrews' curve equation was applied to 40 selected meteorological stations to identify homogenous stations to form unique clusters. A methodology using peak FFDI from cluster averaged FFDIs was developed by applying Log Pearson Type III (LPIII) distribution to generate FFCs. A total of nine homogeneous clusters across Victoria were identified, and subsequently their FFC's were developed in order to estimate the regionalised fire occurrence characteristics.

History of wildland fires on Vandenberg Air Force Base, California

NASA Technical Reports Server (NTRS)

Hickson, Diana E.

1988-01-01

The fire history of the past 50 years for Vandenberg AFB, California was determined using aerial photography, field investigation, and historical and current written records. This constitutes a record of the vegetation age classes for the entire base. The location, cause, and fuel type for sixty fires from this time period were determined. The fires were mapped and entered into a geographic infomation system (GIS) for Vandenberg. Fire history maps derived from this GIS were printed at 1:9600 scale and are on deposit at the Vandenberg Environmental Task Force Office. Although some ecologically significant plant communities on Vandenberg are adapted to fire, no natural fire frequency could be determined, since only one fire possibly caused by lightning occurred in the area now within the base since 1937. Observations made during this study suggest that burning may encourage the invasion of exotic species into chaparral, in particular Burton Mesa or sandhill chaparral, an unusual and geographically limited form of chaparral found on the base.

Firing patterns in the adaptive exponential integrate-and-fire model.

PubMed

Naud, Richard; Marcille, Nicolas; Clopath, Claudia; Gerstner, Wulfram

2008-11-01

For simulations of large spiking neuron networks, an accurate, simple and versatile single-neuron modeling framework is required. Here we explore the versatility of a simple two-equation model: the adaptive exponential integrate-and-fire neuron. We show that this model generates multiple firing patterns depending on the choice of parameter values, and present a phase diagram describing the transition from one firing type to another. We give an analytical criterion to distinguish between continuous adaption, initial bursting, regular bursting and two types of tonic spiking. Also, we report that the deterministic model is capable of producing irregular spiking when stimulated with constant current, indicating low-dimensional chaos. Lastly, the simple model is fitted to real experiments of cortical neurons under step current stimulation. The results provide support for the suitability of simple models such as the adaptive exponential integrate-and-fire neuron for large network simulations.

Fire regime in Mediterranean ecosystem

NASA Astrophysics Data System (ADS)

Biondi, Guido; Casula, Paolo; D'Andrea, Mirko; Fiorucci, Paolo

2010-05-01

The analysis of burnt areas time series in Mediterranean regions suggests that ecosystems characterising this area consist primarily of species highly vulnerable to the fire but highly resilient, as characterized by a significant regenerative capacity after the fire spreading. In a few years the area burnt may once again be covered by the same vegetation present before the fire. Similarly, Mediterranean conifer forests, which often refers to plantations made in order to reforest the areas most severely degraded with high erosion risk, regenerate from seed after the fire resulting in high resilience to the fire as well. Only rarely, and usually with negligible damages, fire affects the areas covered by climax species in relation with altitude and soil types (i.e, quercus, fagus, abies). On the basis of these results, this paper shows how the simple Drossel-Schwabl forest fire model is able to reproduce the forest fire regime in terms of number of fires and burned area, describing whit good accuracy the actual fire perimeters. The original Drossel-Schwabl model has been slightly modified in this work by introducing two parameters (probability of propagation and regrowth) specific for each different class of vegetation cover. Using model selection methods based on AIC, the model with the optimal number of classes with different fire behaviour was selected. Two different case studies are presented in this work: Regione Liguria and Regione Sardegna (Italy). Both regions are situated in the center of the Mediterranean and are characterized by a high number of fires and burned area. However, the two regions have very different fire regimes. Sardinia is affected by the fire phenomenon only in summer whilst Liguria is affected by fires also in winter, with higher number of fires and larger burned area. In addition, the two region are very different in vegetation cover. The presence of Mediterranean conifers, (Pinus Pinaster, Pinus Nigra, Pinus halepensis) is quite spread in Liguria and is limited in Sardinia. What is common in the two regions is the widespread presence of shrub species frequently spread by fire. The analysis in the two regions thus allows in a rather limited area to study almost all the species that characterize the Mediterranean region. This work shows that the fire regime in Mediterranean area is strongly related with vegetation patterns, is almost totally independent by the cause of ignition, and only partially dependent by fire extinguishing actions.

Differences in human versus lightning fires between urban and rural areas of the boreal forest in interior Alaska

USGS Publications Warehouse

Calef, Monika; Varvak, Anna; McGuire, A. David

2017-01-01

In western North America, the carbon-rich boreal forest is experiencing warmer temperatures, drier conditions and larger and more frequent wildfires. However, the fire regime is also affected by direct human activities through suppression, ignition, and land use changes. Models are important predictive tools for understanding future conditions but they are based on regional generalizations of wildfire behavior and weather that do not adequately account for the complexity of human–fire interactions. To achieve a better understanding of the intensity of human influence on fires in this sparsely populated area and to quantify differences between human and lightning fires, we analyzed fires by both ignition types in regard to human proximity in urban (the Fairbanks subregion) and rural areas of interior Alaska using spatial (Geographic Information Systems) and quantitative analysis methods. We found substantial differences in drivers of wildfire: while increases in fire ignitions and area burned were caused by lightning in rural interior Alaska, in the Fairbanks subregion these increases were due to human fires, especially in the wildland urban interface. Lightning fires are starting earlier and fires are burning longer, which is much more pronounced in the Fairbanks subregion than in rural areas. Human fires differed from lightning fires in several ways: they started closer to settlements and highways, burned for a shorter duration, were concentrated in the Fairbanks subregion, and often occurred outside the brief seasonal window for lightning fires. This study provides important insights that improve our understanding of the direct human influence on recently observed changes in wildfire regime with implications for both fire modeling and fire management.

Spatial patterns in vegetation fires in the Indian region.

PubMed

Vadrevu, Krishna Prasad; Badarinath, K V S; Anuradha, Eaturu

2008-12-01

In this study, we used fire count datasets derived from Along Track Scanning Radiometer (ATSR) satellite to characterize spatial patterns in fire occurrences across highly diverse geographical, vegetation and topographic gradients in the Indian region. For characterizing the spatial patterns of fire occurrences, observed fire point patterns were tested against the hypothesis of a complete spatial random (CSR) pattern using three different techniques, the quadrat analysis, nearest neighbor analysis and Ripley's K function. Hierarchical nearest neighboring technique was used to depict the 'hotspots' of fire incidents. Of the different states, highest fire counts were recorded in Madhya Pradesh (14.77%) followed by Gujarat (10.86%), Maharastra (9.92%), Mizoram (7.66%), Jharkhand (6.41%), etc. With respect to the vegetation categories, highest number of fires were recorded in agricultural regions (40.26%) followed by tropical moist deciduous vegetation (12.72), dry deciduous vegetation (11.40%), abandoned slash and burn secondary forests (9.04%), tropical montane forests (8.07%) followed by others. Analysis of fire counts based on elevation and slope range suggested that maximum number of fires occurred in low and medium elevation types and in very low to low-slope categories. Results from three different spatial techniques for spatial pattern suggested clustered pattern in fire events compared to CSR. Most importantly, results from Ripley's K statistic suggested that fire events are highly clustered at a lag-distance of 125 miles. Hierarchical nearest neighboring clustering technique identified significant clusters of fire 'hotspots' in different states in northeast and central India. The implications of these results in fire management and mitigation were discussed. Also, this study highlights the potential of spatial point pattern statistics in environmental monitoring and assessment studies with special reference to fire events in the Indian region.

Effects of burn temperature on ash nutrient forms and availability from cattail (Typha domingensis) and sawgrass (Cladium jamaicense) in the Florida Everglades.

PubMed

Qian, Y; Miao, S L; Gu, B; Li, Y C

2009-01-01

Plant ash derived from fire plays an important role in nutrient balance and cycling in ecosystems. Factors that determine the composition and availability of ash nutrients include fire intensity (burn temperature and duration), plant species, habitat nutrient enrichment, and leaf type (live or dead leaf). We used laboratory simulation methods to evaluate temperature effects on nutrient composition and metals in the residual ash of sawgrass (Cladium jamaicense) and cattail (Typha domingensis), particularly on post-fire phosphorus (P) availability in plant ash. Live and dead leaf samples were collected from Water Conservation Area 2A in the northern Everglades along a soil P gradient, where prescribed fire may be used to accelerate recovery of this unique ecosystem. Significant decreases in total carbon and total nitrogen were detected with increasing fire temperature. Organic matter combustion was nearly complete at temperatures > or = 450 degrees C. HCl-extractable P (average, 50% of total P in the ash) and NH(4)Cl-extractable P (average, 33% of total P in the ash) were the predominant P fractions for laboratory-burned ash. Although a low-intensity fire could induce an elevation of P availability, an intense fire generally resulted in decreased water-soluble P. Significant differences in nutrient compositions were observed between species, habitat nutrient status, and leaf types. More labile inorganic P remained in sawgrass ash than in cattail ash; hence, sawgrass ash has a greater potential to release available P than cattail. Fire intensity affected plant ash nutrient composition, particularly P availability, and the effects varied with plant species and leaf type. Therefore, it is important to consider fire intensity and vegetation community when using a prescribed fire for ecosystem management.

Emissions from an automobile fire.

PubMed

Lönnermark, Anders; Blomqvist, Per

2006-02-01

The emissions from automobile fires have been investigated. The main gas phase components were analysed in small-scale tests with representative material from an automobile. A more detailed investigation of full-scale simulated automobile fires was also conducted, including the characterisation of gas phase components, particulates and run-off water from extinguishing activities. Three separate full scale fire tests have been characterised: a fire ignited and developed in the engine compartment; a fire ignited inside the coupé, that was extinguished in the early stages; and a similar fire ignited inside the coupé that was allowed to spread until the entire vehicle was involved in the fire. The quantitative analysis of the smoke gases from the full-scale fires showed that emissions with a potentially negative impact on the environment, or chronic toxic effect on humans, were produced in significant quantities. These emissions included HCl, SO2, VOCs (e.g. benzene), PAHs, and PCDDs/PCDFs. Analysis of run-off water indicated that it was severely contaminated, containing elevated levels of both organic compounds and metals. Comparison with data from other vehicle fires found in the literature shows that contamination by lead, copper, zinc, and antimony appears to be significant in water run-off from these types of fires.

Mid-term fire danger index based on satellite imagery and ancillary geographic data

NASA Astrophysics Data System (ADS)

Stefanidou, A.; Dragozi, E.; Tompoulidou, M.; Stepanidou, L.; Grigoriadis, D.; Katagis, T.; Stavrakoudis, D.; Gitas, I.

2017-09-01

Fire danger forecast constitutes one of the most important components of integrated fire management since it provides crucial information for efficient pre-fire planning, alertness and timely response to a possible fire event. The aim of this work is to develop an index that has the capability of predicting accurately fire danger on a mid-term basis. The methodology that is currently under development is based on an innovative approach that employs dry fuel spatial connectivity as well as biophysical and topological variables for the reliable prediction of fire danger. More specifically, the estimation of the dry fuel connectivity is based on a previously proposed automated procedure implemented in R software that uses Moderate Resolution Imaging Spectrometer (MODIS) time series data. Dry fuel connectivity estimates are then combined with other ancillary data such as fuel type and proximity to roads in order to result in the generation of the proposed mid-term fire danger index. The innovation of the proposed index—which will be evaluated by comparison to historical fire data—lies in the fact that its calculation is almost solely affected by the availability of satellite data. Finally, it should be noted that the index is developed within the framework of the National Observatory of Forest Fires (NOFFi) project.

Cost-benefit analysis of passive fire protections in road LPG transportation.

PubMed

Paltrinieri, Nicola; Bonvicini, Sarah; Spadoni, Gigliola; Cozzani, Valerio

2012-02-01

The cost-benefit evaluation of passive fire protection adoption in the road transport of liquefied petroleum gas (LPG) was investigated. In a previous study, mathematical simulations of real scale fire scenarios proved the effectiveness of passive fire protections in preventing the "fired" boiling liquid expanding vapor explosion (BLEVE), thus providing a significant risk reduction. In the present study the economical aspects of the adoption of fire protections are analyzed and an approach to cost-benefit analysis (CBA) is proposed. The CBA model is based on the comparison of the risk reduction due to fire protections (expressed in monetary terms by the value of a statistical life) and the cost of the application of fire protections to a fleet of tankers. Different types of fire protections were considered, as well as the possibility to apply protections to the entire fleet or only to a part of it. The application of the proposed model to a real-life case study is presented and discussed. Results demonstrate that the adoption of passive fire protections on road tankers, though not compulsory in Europe, can be economically feasible, thus representing a concrete measure to achieve control of the "major hazard accidents" cited by the European legislation. © 2011 Society for Risk Analysis.

Two-target game model of an air combat with fire-and-forget all-aspect missiles

NASA Technical Reports Server (NTRS)

Davidovitz, A.; Shinar, J.

1989-01-01

An air combat duel between similar aggressive fighter aircraft, both equipped with the same type of guided missiles, is formulated as a two-target differential game using the dynamic model of the game of two identical cars. Each of the identical target sets represents the effective firing envelope of an all-aspect fire-and-forget air-to-air missile. The firing range limits depend on the target aspect angle and are approximated by analytical functions. The maximum range, computed by taking into account the optimal missile avoidance maneuver of the target, determines the no-escape firing envelope. The solution consists of the decomposition of the game space into four regions: the respective winning zones of the two opponents, the draw zone, and the region where the game terminates by a mutual kill. The solution provides a new insight for future air combat analysis.

Individual Aerosol Particle Types Produced by Savanna Burning

NASA Astrophysics Data System (ADS)

Posfai, M.; Simonics, R.; Li, J.; Hobbs, P. V.; Buseck, P. R.; Buseck, P. R.

2001-12-01

We used analytical transmission electron microscopy (TEM) to study individual aerosol particles that were collected on the University of Washington Convair-580 research aircraft over southern Africa during the Safari2000 Dry Season Experiment. Our goals were to study the compositions, morphologies, and mixing states of carbonaceous particles, in order to better understand the physical and chemical properties of biomass smoke on the individual-particle level. The compositions of single particles were determined using energy-dispersive x-ray spectrometry (EDS) and electron energy-loss spectroscopy (EELS). Energy-loss maps obtained with the TEM are useful for studying the spatial distribution of light elements such as carbon within the particles; thus, they provide a detailed picture of complex particles. Carbonaceous particles were assigned into three main groups on the basis of morphology and composition: "organic particles with inorganic inclusions," "tar balls," and "soot." Soot is recognized by its characteristic morphology and microstructure. The distinction between "organic particles with inorganic inclusions" and "tar balls" is somewhat arbitrary, since the two criteria that are used for their distinction (composition and aspect ratio) change continually. The relative concentrations of the three major particle types vary with the type of fire and distance from fire. In the plume of a smoldering fire west of Beria (August 31) the relative concentration of tar balls increased with aging of the plume. Tar balls have a fairly narrow size distribution with a maximum between 100 and 200 nm (diameter). The inorganic K-salt inclusions (KCl, K2SO4, KNO3) within "organic particles" should make these particles hygroscopic, regardless of the properties of the organic compounds. Aging causes the conversion of KCl into K2SO4, KNO3. Aerosol production from flaming and smoldering fires was compared over Kruger National Park on August 17; more soot and more Cl-rich inclusions in organic particles were produced by the flaming fire than by the smoldering fire. Further sets of samples from other flights of Safari2000 are being studied.

Bird functional diversity decreases with time since disturbance: Does patchy prescribed fire enhance ecosystem function?.

PubMed

Sitters, Holly; Di Stefano, Julian; Christie, Fiona; Swan, Matthew; York, Alan

2016-01-01

Animal species diversity is often associated with time since disturbance, but the effects of disturbances such as fire on functional diversity are unknown. Functional diversity measures the range, abundance, and distribution of trait values in a community, and links changes in species composition with the consequences for ecosystem function. Improved understanding of the relationship between time since fire (TSF) and functional diversity is critical given that the frequency of both prescribed fire and wildfire is expected to increase. To address this knowledge gap, we examined responses of avian functional diversity to TSF and two direct measures of environmental heterogeneity, plant diversity, and structural heterogeneity. We surveyed birds across a 70-year chronosequence spanning four vegetation types in southeast Australia. Six bird functional traits were used to derive four functional diversity indices (richness, evenness, divergence, and dispersion) and the effects of TSF, plant diversity and structural heterogeneity on species richness and the functional diversity indices were examined using mixed models. We used a regression tree method to identify traits associated with species more common in young vegetation. Functional richness and dispersion were negatively associated with TSF in all vegetation types, suggesting that recent prescribed fire generates heterogeneous vegetation and provides greater opportunities for resource partitioning. Species richness was not significantly associated with TSF, and is probably an unreliable surrogate for functional diversity in fire-prone systems. A positive, relationship between functional evenness and structural heterogeneity was comnon to all vegetation types, suggesting that fine-scale (tens of meters) structural variation can enhance ecosystem function. Species more common in young vegetation were primarily linked by their specialist diets, indicating that ecosystem services such as seed dispersal and insect control are enhanced in more recently burnt vegetation. We suggest that patchy prescribed fire sustains functional diversity, and that controlled use of patchy fire to break up large expanses of mature vegetation will enhance ecosystem function.

Simulations of Forest Fires by the Cellular Automata Model "ABBAMPAU"

NASA Astrophysics Data System (ADS)

di Gregorio, S.; Bendicenti, E.

2003-04-01

Forest fires represent a serious environmental problem, whose negative impact is becoming day by day more worrisome. Forest fires are very complex phenomena; that need an interdisciplinary approach. The adopted method to modelling involves the definition of local rules, from which the global behaviour of the system can emerge. The paradigm of Cellular Automata was applied and the model ABBAMPAU was projected to simulate the evolution of forest fires. Cellular Automata features (parallelism and a-centrism) seem to match the system "forest fire"; the parameters, describing globally a forest fire, i.e. propagation rate, flame length and direction, fireline intensity, fire duration time et c. are mainly depending on some local characteristics i.e. vegetation type (live and dead fuel), relative humidity, fuel moisture, heat, territory morphology (altitude, slope), et c.. The only global characteristic is given by wind velocity and direction, but wind velocity and direction is locally altered according to the morphology; therefore wind has also to be considered at local level. ABBAMPAU accounts for the following aspects of the phenomenon: effects of combustion in surface and crown fire inside the cell, crown fire triggering off; surface and crown fire spread, determination of the local wind rate and direction. A validation of ABBAMPAU was tested on a real case of forest fire, in the territory of Villaputzu, Sardinia island, August 22nd, 1998. First simulations account for the main characteristics of the phenomenon and agree with the observations. The results show that the model could be applied for the forest fire preventions, the productions of risk scenarios and the evaluation of the forest fire environmental impact.

Modelling the meteorological forest fire niche in heterogeneous pyrologic conditions.

PubMed

De Angelis, Antonella; Ricotta, Carlo; Conedera, Marco; Pezzatti, Gianni Boris

2015-01-01

Fire regimes are strongly related to weather conditions that directly and indirectly influence fire ignition and propagation. Identifying the most important meteorological fire drivers is thus fundamental for daily fire risk forecasting. In this context, several fire weather indices have been developed focussing mainly on fire-related local weather conditions and fuel characteristics. The specificity of the conditions for which fire danger indices are developed makes its direct transfer and applicability problematic in different areas or with other fuel types. In this paper we used the low-to-intermediate fire-prone region of Canton Ticino as a case study to develop a new daily fire danger index by implementing a niche modelling approach (Maxent). In order to identify the most suitable weather conditions for fires, different combinations of input variables were tested (meteorological variables, existing fire danger indices or a combination of both). Our findings demonstrate that such combinations of input variables increase the predictive power of the resulting index and surprisingly even using meteorological variables only allows similar or better performances than using the complex Canadian Fire Weather Index (FWI). Furthermore, the niche modelling approach based on Maxent resulted in slightly improved model performance and in a reduced number of selected variables with respect to the classical logistic approach. Factors influencing final model robustness were the number of fire events considered and the specificity of the meteorological conditions leading to fire ignition.

Modelling the Meteorological Forest Fire Niche in Heterogeneous Pyrologic Conditions

PubMed Central

De Angelis, Antonella; Ricotta, Carlo; Conedera, Marco; Pezzatti, Gianni Boris

2015-01-01

Fire regimes are strongly related to weather conditions that directly and indirectly influence fire ignition and propagation. Identifying the most important meteorological fire drivers is thus fundamental for daily fire risk forecasting. In this context, several fire weather indices have been developed focussing mainly on fire-related local weather conditions and fuel characteristics. The specificity of the conditions for which fire danger indices are developed makes its direct transfer and applicability problematic in different areas or with other fuel types. In this paper we used the low-to-intermediate fire-prone region of Canton Ticino as a case study to develop a new daily fire danger index by implementing a niche modelling approach (Maxent). In order to identify the most suitable weather conditions for fires, different combinations of input variables were tested (meteorological variables, existing fire danger indices or a combination of both). Our findings demonstrate that such combinations of input variables increase the predictive power of the resulting index and surprisingly even using meteorological variables only allows similar or better performances than using the complex Canadian Fire Weather Index (FWI). Furthermore, the niche modelling approach based on Maxent resulted in slightly improved model performance and in a reduced number of selected variables with respect to the classical logistic approach. Factors influencing final model robustness were the number of fire events considered and the specificity of the meteorological conditions leading to fire ignition. PMID:25679957

Fire characteristics associated with firefighter injury on large federal wildland fires.

PubMed

Britton, Carla; Lynch, Charles F; Torner, James; Peek-Asa, Corinne

2013-02-01

Wildland fires present many injury hazards to firefighters. We estimate injury rates and identify fire-related factors associated with injury. Data from the National Interagency Fire Center from 2003 to 2007 provided the number of injuries in which the firefighter could not return to his or her job assignment, person-days worked, and fire characteristics (year, region, season, cause, fuel type, resistance to control, and structures destroyed). We assessed fire-level risk factors of having at least one reported injury using logistic regression. Negative binomial regression was used to examine incidence rate ratios associated with fire-level risk factors. Of 867 fires, 9.5% required the most complex management and 24.7% required the next-highest level of management. Fires most often occurred in the western United States (82.8%), during the summer (69.6%), caused by lightening (54.9%). Timber was the most frequent fuel source (40.2%). Peak incident management level, person-days of exposure, and the fire's resistance to control were significantly related to the odds of a fire having at least one reported injury. However, the most complex fires had a lower injury incidence rate than less complex fires. Although fire complexity and the number of firefighters were associated with the risk for at least one reported injury, the more experienced and specialized firefighting teams had lower injury incidence. Copyright © 2013 Elsevier Inc. All rights reserved.

A Novel Classification System for Injuries After Electronic Cigarette Explosions.

PubMed

Patterson, Scott B; Beckett, Allison R; Lintner, Alicia; Leahey, Carly; Greer, Ashley; Brevard, Sidney B; Simmons, Jon D; Kahn, Steven A

Electronic cigarettes (e-cigarettes) contain lithium batteries that have been known to explode and/or cause fires that have resulted in burn injury. The purpose of this article is to present a case study, review injuries caused by e-cigarettes, and present a novel classification system from the newly emerging patterns of burns. A case study was presented and online media reports for e-cigarette burns were queried with search terms "e-cigarette burns" and "electronic cigarette burns." The reports and injury patterns were tabulated. Analysis was then performed to create a novel classification system based on the distinct injury patterns seen in the study. Two patients were seen at our regional burn center after e-cigarette burns. One had an injury to his thigh and penis that required operative intervention after ignition of this device in his pocket. The second had a facial burn and corneal abrasions when the device exploded while he was inhaling vapor. The Internet search and case studies resulted in 26 cases for evaluation. The burn patterns were divided in direct injury from the device igniting and indirect injury when the device caused a house or car fire. A numerical classification was created: direct injury: type 1 (hand injury) 7 cases, type 2 (face injury) 8 cases, type 3 (waist/groin injury) 11 cases, and type 5a (inhalation injury from using device) 2 cases; indirect injury: type 4 (house fire injury) 7 cases and type 5b (inhalation injury from fire started by the device) 4 cases. Multiple e-cigarette injuries are occurring in the United States and distinct patterns of burns are emerging. The classification system developed in this article will aid in further study and future regulation of these dangerous devices.

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-stand variability in the NDVI (pixel-scale) also returned to pre-fire values within the same time frame but increased with water stress associated with droughts. While these studies indicated that the NDVI of fynbos and chaparral stands recovered to pre-fire values within 10 years, it is recognized that other ecosystem characteristics may take considerably longer to recover. Despite the larger pixel size, MODIS data were found to be more suitable for monitoring vegetation post-fire recovery than TM/ETM+ data, requiring considerably less pre-processing and providing substantially more information regarding phenological characteristics of recovery pathways. Future studies will include consideration of fire history in the post-fire recovery characteristics of vegetation in these two MTEs.

46 CFR 95.05-1 - Fire detecting, manual alarm, and supervised patrol systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... provided a smoke detecting or other suitable type fire detecting system. (c) Enclosed spaces which are “specially suitable for vehicles” shall be fitted with an approved fire or smoke detecting system. [CGFR 66...

46 CFR 95.05-1 - Fire detecting, manual alarm, and supervised patrol systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... provided a smoke detecting or other suitable type fire detecting system. (c) Enclosed spaces which are “specially suitable for vehicles” shall be fitted with an approved fire or smoke detecting system. [CGFR 66...

The estimation of electrical cable fire-induced damage limits

NASA Astrophysics Data System (ADS)

Nowlen, S. P.; Jacobus, M. J.

Sandia National Laboratories has, for several years, been engaged in the performance of both fire safety and electrical equipment qualification research under independent programs sponsored by the US Nuclear Regulatory Commission. Recent comparisons between electrical cable thermal damageability data gathered independently in these two efforts indicate that a direct correlation exists between certain of the recent cable thermal vulnerability information gathered under equipment qualification conditions and thermal damageability in a fire environment. This direct correlation allows for a significant expansion of the data base on estimated cable thermal vulnerability limits in a fire environment because of the wide range of cable types and products that have been evaluated as a part of the equipment qualification research. This paper provides a discussion of the basis for the derived correlation, and presents estimated cable thermal damage limits for a wide range of generic cable types and specific cable products. The supposition that a direct correlation exists is supported through direct comparisons of the test results for certain specific cable products. The proposed supplemental cable fire vulnerability data gained from examination of the equipment qualification results is presented. These results should be of particular interest to those engaged in the evaluation of fire risk for industrial facilities, including nuclear power plants.

Fire risk and adaptation strategies in Northern Eurasian forests

NASA Astrophysics Data System (ADS)

Shvidenko, Anatoly; Schepaschenko, Dmitry

2013-04-01

On-going climatic changes substantially accelerate current fire regimes in Northern Eurasian ecosystems, particularly in forests. During 1998-2012, wildfires enveloped on average ~10.5 M ha year-1 in Russia with a large annual variation (between 3 and 30 M ha) and average direct carbon emissions at ~150 Tg C year-1. Catastrophic fires, which envelope large areas, spread in usually incombustible wetlands, escape from control and provide extraordinary negative impacts on ecosystems, biodiversity, economics, infrastructure, environment, and health of population, become a typical feature of the current fire regimes. There are new evidences of correlation between catastrophic fires and large-scale climatic anomalies at a continental scale. While current climatic predictions suggest the dramatic warming (at the average at 6-7 °C for the country and up to 10-12°C in some northern continental regions), any substantial increase of summer precipitation does not expected. Increase of dryness and instability of climate will impact fire risk and severity of consequences. Current models suggest a 2-3 fold increase of the number of fires by the end of this century in the boreal zone. They predict increases of the number of catastrophic fires; a significant increase in the intensity of fire and amount of consumed fuel; synergies between different types of disturbances (outbreaks of insects, unregulated anthropogenic impacts); acceleration of composition of the gas emissions due to enhanced soil burning. If boreal forests would become a typing element, the mass mortality of trees would increase fire risk and severity. Permafrost melting and subsequent change of hydrological regimes very likely will lead to the degradation and destruction of boreal forests, as well as to the widespread irreversible replacement of forests by other underproductive vegetation types. A significant feedback between warming and escalating fire regimes is very probable in Russia and particularly in the permafrost areas. Overall, Russia should expect a disproportionate escalation of fire regimes compared to increasing climatic fire danger. Thus, development and implementation of an efficient adaptation strategy is a pressing problem of current forest management of the country. An appropriate system of forest fire protection which would be able to meet challenges of future climates is a corner stone of such a strategy. We consider possible systems solutions of this complex problem including (1) integrated ecological and socio-economic analysis of current and future fire regimes; (2) regional requirements to and specific features of a new paradigm of forest fire protection in the boreal zone of Northern Eurasia; (3) anticipatory strategy of the prevention of large-scale disturbances in forests, including adaptation of forest landscapes to the future climates (regulation of tree composition; setup of relevant spatial structure of forest landscapes; etc.); (4) implementation of an effective system of forest monitoring as part of integrated observing systems; (5) transition to ecologically-friendly systems of industrial development of northern territories; (6) development of new/ improvement of existing legislation and institutional frameworks of forest management which would be satisfactory to react on challenges of climate change; and (6) international cooperation.

Assessing accuracy of point fire intervals across landscapes with simulation modelling

Treesearch

Russell A. Parsons; Emily K. Heyerdahl; Robert E. Keane; Brigitte Dorner; Joseph Fall

2007-01-01

We assessed accuracy in point fire intervals using a simulation model that sampled four spatially explicit simulated fire histories. These histories varied in fire frequency and size and were simulated on a flat landscape with two forest types (dry versus mesic). We used three sampling designs (random, systematic grids, and stratified). We assessed the sensitivity of...

Comparing the costs of agency and contract fire crews.

Treesearch

G.H. Donovan

2007-01-01

This paper compares the cost of using Forest Service fire crews versus contract fire crews. Results suggest that if sufficient work is available to keep a Forest Service crew productively employed throughout a fire season, then the daily cost of a Forest Service type II crew is lower than the daily cost of a contract crew.

The Effect of Extinguishing Agents on Burning Sonobuoys Containing Lithium-Sulfur Dioxide Batteries

DTIC Science & Technology

1989-09-01

components and the JP-5. In addition, the types of extinguish- ment materials, such as carbor spheres, that have some degree of success on metal fires , would...NWC TP 6571, publication UNCLASSIFIED.) 8. John F. Riley. "Na-X, a New Fire Extinguishing Agent for Metal Fires ," Fire Technology, Vol. 10, No. 4

7 CFR 29.1018 - Fire-killed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Fire-killed. 29.1018 Section 29.1018 Agriculture... Type 92) § 29.1018 Fire-killed. Any leaf of which 5 percent or more of its surface has a set green... tobacco may be described as fire-killed. (See Rule 23.) [42 FR 21092, Apr. 25, 1977. Redesignated at 51 FR...

Fire-retardant-treated strandboard : properties and fire performance

Treesearch

Jerrold Winandy; Qingwen Wang; Robert H. White

2008-01-01

This study evaluated a series of single-layer, randomly oriented strandboard panels made with one resin type, a single resin loading level, and four fire-retardant-treatment levels. The fire retardant (FR) evaluated was a pH-buffered combination of boric acid and organic phosphate. Siberian larch strands were separated into five batches. One batch of strands served as...

First Order Fire Effects Model: FOFEM 4.0, user's guide

Treesearch

Elizabeth D. Reinhardt; Robert E. Keane; James K. Brown

1997-01-01

A First Order Fire Effects Model (FOFEM) was developed to predict the direct consequences of prescribed fire and wildfire. FOFEM computes duff and woody fuel consumption, smoke production, and fire-caused tree mortality for most forest and rangeland types in the United States. The model is available as a computer program for PC or Data General computer.

A tree-ring based fire history of riparian reserves in the Klamath Mountains.

Treesearch

Carl N. Skinner

2003-01-01

Surprisingly little fire history information is available for riparian environments despite their ecological importance. Thus, there is a great deal of uncertainty about the ecological role of fire in riparian environments. Considering the Mediterranean climate and the general pattern of frequent low-moderate severity fires in most vegetation types, it is logical to...

Developing fire management mixes for fire program planning

Treesearch

Armando González-Cabán; Patricia B. Shinkle; Thomas J. Mills

1986-01-01

Evaluating economic efficiency of fire management program options requires information on the firefighting inputs, such as vehicles and crews, that would be needed to execute the program option selected. An algorithm was developed to translate automatically dollars allocated to type of firefighting inputs to numbers of units, using a set of weights for a specific fire...

Pharmacological characterization of ionic currents that regulate high-frequency spontaneous activity of electromotor neurons in the weakly electric fish, Apteronotus leptorhynchus.

PubMed

Smith, G Troy

2006-01-01

The neural circuit that controls the electric organ discharge (EOD) of the brown ghost knifefish (Apteronotus leptorhynchus) contains two spontaneous oscillators. Both pacemaker neurons in the medulla and electromotor neurons (EMNs) in the spinal cord fire spontaneously at frequencies of 500-1,000 Hz to control the EOD. These neurons continue to fire in vitro at frequencies that are highly correlated with in vivo EOD frequency. Previous studies used channel blocking drugs to pharmacologically characterize ionic currents that control high-frequency firing in pacemaker neurons. The goal of the present study was to use similar techniques to investigate ionic currents in EMNs, the other type of spontaneously active neuron in the electromotor circuit. As in pacemaker neurons, high-frequency firing of EMNs was regulated primarily by tetrodotoxin-sensitive sodium currents and by potassium currents that were sensitive to 4-aminopyridine and kappaA-conotoxin SIVA, but resistant to tetraethylammonium. EMNs, however, differed from pacemaker neurons in their sensitivity to some channel blocking drugs. Alpha-dendrotoxin, which blocks a subset of Kv1 potassium channels, increased firing rates in EMNs, but not pacemaker neurons; and the sodium channel blocker muO-conotoxin MrVIA, which reduced firing rates of pacemaker neurons, had no effect on EMNs. These results suggest that similar, but not identical, ionic currents regulate high-frequency firing in EMNs and pacemaker neurons. The differences in the ionic currents expressed in pacemaker neurons and EMNs might be related to differences in the morphology, connectivity, or function of these two cell types.

Lead particle size and its association with firing conditions and range maintenance: implications for treatment.

PubMed

Dermatas, Dimitris; Chrysochoou, Maria

2007-08-01

Six firing range soils were analyzed, representing different environments, firing conditions, and maintenance practices. The particle size distribution and lead (Pb) concentration in each soil fraction were determined for samples obtained from the backstop berms. The main factors that were found to influence Pb fragment size were the type of soil used to construct the berms and the type of weapon fired. The firing of high velocity weapons, i.e., rifles, onto highly angular soils induced significant fragmentation of the bullets and/or pulverization of the soil itself. This resulted in the accumulation of Pb in the finer soil fractions and the spread of Pb contamination beyond the vicinity of the backstop berm. Conversely, the use of clay as backstop and the use of low velocity pistols proved to be favorable for soil clean-up and range maintenance, since Pb was mainly present as large metallic fragments that can be recovered by a simple screening process. Other factors that played important roles in Pb particle size distribution were soil chemistry, firing distance, and maintenance practices, such as the use of water spray for dust suppression and deflectors prior to impact. Overall, coarse Pb particles provide much easier and more cost-effective maintenance, soil clean-up, and remediation via physical separation. Fine Pb particles release Pb more easily, pose an airborne Pb hazard, and require the application of stabilization/solidification treatment methods. Thus, to ensure sustainable firing range operations by means of cost-effective design, maintenance, and clean-up, especially when high velocity weapons are used, the above mentioned factors should be carefully considered.

[Effects of three types of veneering porcelain on bending strength of KAVO(TM) Y-TZP/porcelain bilayered structure].

PubMed

Ma, Ting-ting; Yi, Yuan-fu; Shao, Long-quan; Tian, Jie-mo; Hou, Kang-lin; Zhang, Wei-wei; Wen, Ning; Deng, Bin

2010-10-01

To investigate the effect of three types of veneering porcelain on the bending strength of KAVO Y-TZP/porcelain layered structure. KAVO zirconia ceramics were used as the substructure. To form Y-TZP/porcelain bilayered structure, a leucite-based veneering porcelain was fired on the zirconia substructures by slip-casting technique with dentin washbake, and two nano-fluorapatite-based veneering porcelains were fired on the zirconia substructures by either slip-casting or pressed-on technique with or without liner coverage. The bending strength was tested according to ISO 6872 standard, and the veneered surfaces of the fracture samples were analyzed by scanning electron microscopy (SEM). For covering KAVO zirconia core material, the conventional veneering slurry-porcelain combined with liner or wash firing had significant higher bending strength than pressed-on porcelain. SEM showed that the main failure type at the interface was adhesive failure. Thin layer sintering using washbake program or liner on KAVO zirconia surface increases the surface wettability, and this procedure may be indispensable when veneering on the surface of dental zirconia.

Normalized burn ratios link fire severity with patterns of avian occurrence

USGS Publications Warehouse

Rose, Eli T.; Simons, Theodore R.; Klein, Rob; McKerrow, Alexa

2016-01-01

ContextRemotely sensed differenced normalized burn ratios (DNBR) provide an index of fire severity across the footprint of a fire. We asked whether this index was useful for explaining patterns of bird occurrence within fire adapted xeric pine-oak forests of the southern Appalachian Mountains.ObjectivesWe evaluated the use of DNBR indices for linking ecosystem process with patterns of bird occurrence. We compared field-based and remotely sensed fire severity indices and used each to develop occupancy models for six bird species to identify patterns of bird occurrence following fire.MethodsWe identified and sampled 228 points within fires that recently burned within Great Smoky Mountains National Park. We performed avian point counts and field-assessed fire severity at each bird census point. We also used Landsat™ imagery acquired before and after each fire to quantify fire severity using DNBR. We used non-parametric methods to quantify agreement between fire severity indices, and evaluated single season occupancy models incorporating fire severity summarized at different spatial scales.ResultsAgreement between field-derived and remotely sensed measures of fire severity was influenced by vegetation type. Although occurrence models using field-derived indices of fire severity outperformed those using DNBR, summarizing DNBR at multiple spatial scales provided additional insights into patterns of occurrence associated with different sized patches of high severity fire.ConclusionsDNBR is useful for linking the effects of fire severity to patterns of bird occurrence, and informing how high severity fire shapes patterns of bird species occurrence on the landscape.

Characterization of biomass burning aerosols produced in the laboratory with a light-scattering aerosol mass spectrometer

NASA Astrophysics Data System (ADS)

Middlebrook, A. M.; Adler, G. A.; Coggon, M.; De Gouw, J. A.; Franchin, A.; Gilman, J.; Koss, A.; Krechmer, J. E.; Lamb, K.; Manfred, K.; Roberts, J. M.; Schwarz, J. P.; Sekimoto, K.; Selimovic, V.; Stockwell, C.; Wagner, N.; Warneke, C.; Washenfelder, R. A.; Womack, C.; Yokelson, R. J.; Yuan, B.

2017-12-01

During the 2016 NOAA FIREX project at the Missoula Fire Sciences Laboratory, small fires of known fuel type and properties were ignited to characterize their direct emissions with a large variety of new sampling methods. Two types of experiments were employed: sampling smoke directly from the exhaust stack throughout the lifecycle of the fires (stack burns) or sampling when the exhaust vent was closed to fill the room with smoke (room burns). For both types of burns, photo-oxidation chambers were at times used to mimic aging in the atmosphere. During all these experiments, we measured the non-refractory components of the smoke particles using an Aerodyne compact time-of-flight aerosol mass spectrometer (AMS) with a light scattering module and diluted the sample line as little as possible (usually by a factor of 10) without overwhelming our instrument. For the stack burns, our AMS was placed near the top of the exhaust stack to capture the composition and size distribution during the rapidly changing stages of the fires. We found that the chemical composition of the aerosols varied with fuel type and combustion conditions on time scales of a few minutes as the fuels went through different stages of heating and combustion. For the room burns, we obtained additional measurements with the light-scattering module aimed at understanding how well smoke particles are measured with the AMS, along with characterization of their physical properties. We will present a summary of our results, with connections to their relevance for constraining model treatments of fire emissions on the atmosphere.

Carbon Emission from Forest Fires on Scots Pine Logging Sites in the Angara Region of Central Siberia

NASA Astrophysics Data System (ADS)

Ivanova, G. A.; Conard, S. G.; McRae, D. J.; Kukavskaya, E. A.; Bogorodskaya, A. V.; Kovaleva, N. M.

2010-12-01

Wildfire and large-scale forest harvesting are the two major disturbances in the Russian boreal forests. Non-recovered logged sites total about a million hectares in Siberia. Logged sites are characterized by higher fire hazard than forest sites due to the presence of generally untreated logging slash (i.e., available fuel) which dries out much more rapidly compared to understory fuels. Moreover, most logging sites can be easily accessed by local population; this increases the risk for fire ignition. Fire impacts on the overstory trees, subcanopy woody layer, and ground vegetation biomass were estimated on 14 logged and unlogged comparison sites in the Lower Angara Region in 2009-2010 as part of the NASA-funded NEESPI project, The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia. Based on calculated fuel consumption, we estimated carbon emission from fires on both logged and unlogged burned sites. Carbon emission from fires on logged sites appeared to be twice that on unlogged sites. Soil respiration decreased on both site types after fires. This reduction may partially offset fire-produced carbon emissions. Carbon emissions from fire and post-fire ecosystem damage on logged sites are expected to increase under changing climate conditions and as a result of anticipated increases in future forest harvesting in Siberia.

A land management history for central Queensland, Australia as determined from land-holder questionnaire and aerial photography.

PubMed

Fensham, Roderick J; Fairfax, Russell J

2003-08-01

Features of the land management history over a 125,755 km(2) area of central Queensland, Australia were determined from a variety of sources. A random sample of 205 site locations provided the basis for determining trends in land use. Trends in vegetation clearing were determined using sequential aerial photography for the sample sites, revealing a steady rate averaging nearly 1% of the region per annum over 41 years. This measure of sustained clearing over a large region is higher than recently published clearing rates from South America. Land types have been selectively cleared with over 90% of the Acacia on clay land type having been cleared. A land-holder questionnaire pertaining to the random sites yielded a response rate of 71% and provided information on vegetation clearing, ploughing, tree killing (ring-barking or tree poisoning), and fire frequency, season and intensity. The land-holder responses were compared with independent data sources where possible and revealed no mis-information. However, land-holders may have been marginally less likely to respond if the sample area had been cleared, although this effect was not statistically significant. Ploughing and tree killing are variable depending on land type, but the former has affected about 40% of the Acacia on clay land type, effectively eliminating options for natural regrowth. The proportion of decade-site combinations that were reported as having no fires increased from 22% in the 1950s to an average of 42% for subsequent decades, although the reporting of more than one fire per decade has been relatively constant through the study period. The reporting of at least one fire per decade varies from 46% for the Acacia on sand land type to 77% for the Eucalypt on sand land type for decade-site combinations. Fires are more intense when associated with clearing than in uncleared vegetation, but the proportion of cool and hot fires is relatively constant between land types in uncleared vegetation. Nearly all fires reported were either in spring or summer and this seasonally restricted regime is probably at variance with Aboriginal fire regimes. This study describes the rapid transformation of central Queensland. This has yielded substantially increased agricultural production but may also result in a range of negative impacts and these are discussed.

Carbon, fire, and fuels: The importance of fuels and fuel characterization and the status of wildland fire fuels data for the United States

NASA Astrophysics Data System (ADS)

French, N. H. F.; Prichard, S.; McKenzie, D.; Kennedy, M. C.; Billmire, M.; Ottmar, R. D.; Kasischke, E. S.

2016-12-01

Quantification of emissions of carbon during combustion relies on knowing three general variables: how much landscape is impacted by fire (burn area), how much carbon is in that landscape (fuel loading), and fuel properties that determine the fraction that is consumed (fuel condition). These variables also determine how much carbon remains at the site in the form of unburned organic material or char, and therefore drive post-fire carbon dynamics and pools. In this presentation we review the importance of understanding fuel type, fuel loading, and fuel condition for quantifying carbon dynamics properly during burning and for measuring and mapping fuels across landscapes, regions, and continents. Variability in fuels has been shown to be a major driver of uncertainty in fire emissions, but has had little attention until recently. We review the current state of fuel characterization for fire management and carbon accounting, and present a new approach to quantifying fuel loading for use in fire-emissions mapping and for improving fire-effects assessment. The latest results of a study funded by the Joint Fire Science Program (JFSP) are presented, where a fuel loading database is being built to quantify variation in fuel loadings, as represented in the Fuel Characteristic Classification System (FCCS), across the conterminous US and Alaska. Statistical assessments of these data at multiple spatial scales will improve tools used by fire managers and scientists to quantify fire's impact on the land, atmosphere, and carbon cycle.

Changes to Cretaceous surface fire behaviour influenced the spread of the early angiosperms.

PubMed

Belcher, Claire M; Hudspith, Victoria A

2017-02-01

Angiosperms evolved and diversified during the Cretaceous period. Early angiosperms were short-stature weedy plants thought to have increased fire frequency and mortality in gymnosperm forest, aiding their own expansion. However, no explorations have considered whether the range of novel fuel types that diversified throughout the Cretaceous also altered fire behaviour, which should link more strongly to mortality than fire frequency alone. We measured ignitability and heat of combustion in analogue Cretaceous understorey fuels (conifer litter, ferns, weedy and shrubby angiosperms) and used these data to model palaeofire behaviour. Variations in ignition, driven by weedy angiosperms alone, were found to have been a less important feedback to changes in Cretaceous fire activity than previously estimated. Our model estimates suggest that fires in shrub and fern understories had significantly greater fireline intensities than those fuelled by conifer litter or weedy angiosperms, and whilst fern understories supported the most rapid fire spread, angiosperm shrubs delivered the largest amount of heat per unit area. The higher fireline intensities predicted by the models led to estimates of enhanced scorch of the gymnosperm canopy and a greater chance of transitioning to crown fires. Therefore, changes in fire behaviour driven by the addition of new Cretaceous fuel groups may have assisted the angiosperm expansion. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Santa Ana Winds and Fire Regimes of Southern California National Forests

NASA Astrophysics Data System (ADS)

Bendix, J.

2015-12-01

In Southern California, it has long been understood that foehn-type Santa Ana winds are an important factor in the occurrence of large wildfires. Although a variety of anecdotal observations and statistical analyses have confirmed the importance of these winds to wildfire, particularly in the Fall months when Santa Ana winds overlap with dry fuels from summer drought, many of the details of those winds' impacts on fire remain obscure. This paper uses data regarding individual fires from California's Fire and Resource Assessment Program database and a compilation of Santa Ana Wind days (SAW days) published by Abatzoglou et al. in 2013 to assess the relationship of Santa Ana winds to fire occurrence and size in Southern California. The analysis included 474 fires larger than 20 ha (~50 acres).that burned on the four Southern California national forests (Angeles, Cleveland, Los Padres and San Bernardino) between 1948 and 2010. Overall, just 10.3% of the fires started on SAW days, and 14.4% experienced at least one SAW day between start and containment dates. The impact of Santa Ana winds is greater, however, with increasing fire size. For fires > 4000 ha, 18.4% began on SAW days, with 30.4% experiencing at least one SAW day before containment. And 20% of fires > 20000 ha started on SAW days, with 50% including one or more SAW days. Fires beginning on SAW days were larger, with a mean of 6239 ha compared to 2150 ha for fires that began on non-SAW days. Only 2% of the fires that began on SAW days were started by lightning, suggesting that the impact of Santa Ana winds on Southern California fire regimes may be enhanced by humans' role in ignitions.

40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

Code of Federal Regulations, 2012 CFR

2012-07-01

... one-quarter extension of the deadline for the next fuel flowmeter system accuracy test may be claimed... protocol no later than 45 days after the completion of all certification tests. 2. Procedure 2.1Fuel... applicable): by design (orifice, nozzle, and venturi-type flowmeters, only) or by measurement under...

40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

Code of Federal Regulations, 2010 CFR

2010-07-01

... one-quarter extension of the deadline for the next fuel flowmeter system accuracy test may be claimed... protocol no later than 45 days after the completion of all certification tests. 2. Procedure 2.1Fuel... applicable): by design (orifice, nozzle, and venturi-type flowmeters, only) or by measurement under...

40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

Code of Federal Regulations, 2013 CFR

2013-07-01

... one-quarter extension of the deadline for the next fuel flowmeter system accuracy test may be claimed... protocol no later than 45 days after the completion of all certification tests. 2. Procedure 2.1Fuel... applicable): by design (orifice, nozzle, and venturi-type flowmeters, only) or by measurement under...

Ponderosa pine, mixed conifer, and spruce-fir forests [Chapter 2

Treesearch

Michael A. Battaglia; Wayne D. Shepperd

2007-01-01

Before European settlement of the interior west of the United States, coniferous forests of this region were influenced by many disturbance regimes, primarily fires, insects, diseases, and herbivory, which maintained a diversity of successional stages and vegetative types across landscapes. Activities after settlement, such as fire suppression, grazing, and logging...

46 CFR 160.031-5 - Approval and production tests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Line-Throwing Appliance, Shoulder Gun Type (and... test. The operational test must be conducted as follows: (1) Three rounds must be fired by the gun, at... of the projectile must be in accordance with § 160.031-3(d) the gun must fire each round properly and...

46 CFR 160.031-5 - Approval and production tests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Line-Throwing Appliance, Shoulder Gun Type (and... test. The operational test must be conducted as follows: (1) Three rounds must be fired by the gun, at... of the projectile must be in accordance with § 160.031-3(d) the gun must fire each round properly and...

46 CFR 160.031-5 - Approval and production tests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Line-Throwing Appliance, Shoulder Gun Type (and... test. The operational test must be conducted as follows: (1) Three rounds must be fired by the gun, at... of the projectile must be in accordance with § 160.031-3(d) the gun must fire each round properly and...

46 CFR 160.031-5 - Approval and production tests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Line-Throwing Appliance, Shoulder Gun Type (and... test. The operational test must be conducted as follows: (1) Three rounds must be fired by the gun, at... of the projectile must be in accordance with § 160.031-3(d) the gun must fire each round properly and...

46 CFR 160.031-5 - Approval and production tests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Line-Throwing Appliance, Shoulder Gun Type (and... test. The operational test must be conducted as follows: (1) Three rounds must be fired by the gun, at... of the projectile must be in accordance with § 160.031-3(d) the gun must fire each round properly and...

Fuel dynamics and fire behaviour in Australian mallee and heath vegetation

Treesearch

Juanita Myers; Jim Gould; Miguel Cruz; Meredith Henderson

2007-01-01

In southern Australia, shrubby heath vegetation together with woodlands dominated by multistemmed eucalypts (mallee) comprise areas of native vegetation with important biodiversity values. These vegetation types occur in semiarid and mediterranean climates and can experience large frequent fires. This study is investigating changes in the fuel complex with time, fuel...

Experimental Extinguishment of Fires by Blast.

DTIC Science & Technology

1982-05-01

Icopmy DTIC TAB I Unan-nounced Approved by: Justiri cat i O__ : R. C. Phillips, Director Chemical Engineering Laboratory D1str1i.:: to,/ G. R...SRI study. Of interest this year has been the role played by fuel type--notably, the Dertinent physico- chemical properties--compared with the...perturbing geometries on fire behavior. Present tests on common liquid fuels representing various combinations of physico- chemical properties demonstrate

Vulnerability of North American Boreal Peatlands to Interactions between Climate, Hydrology, and Wildland Fires

NASA Astrophysics Data System (ADS)

Bourgeau-Chavez, L. L.; Jenkins, L. K.; Kasischke, E. S.; Turetsky, M.; Benscoter, B.; Banda, E. J.; Boren, E. J.; Endres, S. L.; Billmire, M.

2013-12-01

North American boreal peatland sites of Alaska, Alberta Canada, and the southern limit of the boreal ecoregion (Michigan's Upper Peninsula) are the focus of an ongoing project to better understand the fire weather, hydrology, and climatic controls on boreal peatland fires. The overall goal of the research project is to reduce uncertainties of the role of northern high latitude ecosystems in the global carbon cycle and to improve carbon emission estimates from boreal fires. Boreal peatlands store tremendous reservoirs of soil carbon that are likely to become increasingly vulnerable to fire as climate change lowers water tables and exposes C-rich peat to burning. Increasing fire activity in peatlands could cause these ecosystems to become net sources of C to the atmosphere, which is likely to have large influences on atmospheric carbon concentrations through positive feedbacks that enhance climate warming. Remote sensing is key to monitoring, understanding and quantifying changes occurring in boreal peatlands. Remote sensing methods are being developed to: 1) map and classify peatland cover types; 2) characterize seasonal and inter-annual variations in the moisture content of surface peat (fuel) layers; 3) map the extent and seasonal timing of fires in peatlands; and 4) discriminate different levels of fuel consumption/burn severity in peat fires. A hybrid radar and optical infrared methodology has been developed to map peatland types (bog vs. fen) and level of biomass (open herbaceous, shrubby, forested). This methodology relies on multi-season data to detect phenological changes in hydrology which characterize the different ecosystem types. Landsat data are being used to discriminate burn severity classes in the peatland types using standard dNBR methods as well as individual bands. Cross referencing the peatland maps and burn severity maps will allow for assessment of the distribution of upland and peatland ecosystems affected by fire and quantitative analysis of emissions. Radar imagery from multiple platforms (L-band PALSAR, C-band ERS-2, Envisat, and Radarsat-2) is being used to develop soil moisture extraction algorithms to monitor changes (drying - wetting) through time and to develop a standard method for soil moisture assessment. Using data from the 1990s (ERS-1 and 2) through the present (Radarsat-2) will allow for determination of patterns of wetting and drying across the landscape. All the remote sensing analysis is supported with field work which has been coordinated with that of Canadian scientists. Field collection includes vegetation and hydrology data to validate peatland distribution maps, collection of water table depths and peat moisture content data to aid in algorithm development for radar organic soil moisture retrieval, and characterization of variations in depth of burning and carbon consumption during peatland fires to use in burn severity mapping and fire emissions modeling.

Evaluation and Testing of Rail Transit Undercar Fire Detection and Suppression Systems

DOT National Transportation Integrated Search

1989-08-01

This document presents the results of a comprehensive review and evaluation of transit undercar fire detection and suppression methods. The evaluation of fire detection method resulted in a recommendation that continuous wire type linear thermal dete...

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.

Mapping Chaparral in the Santa Monica Mountains Using Multiple Spectral Mixture Models

NASA Technical Reports Server (NTRS)

Green Robert O.; Roberts, D. A.; Gardner, M.; Church, R.; Ustin, S.; Scheer, G.

1996-01-01

California chaparral is one of the most important natural vegetation communities in Southern California, representing a significant source of species diversity and, through a high susceptibility to fire, playing a major role in ecosystem dynamics. Due to steep topographic gradients, harsh edaphic conditions and variable fire histories, chaparral typically forms a complex mosaic of different species dominants and age classes, each with unique successional responses to fire and canopy characteristics (e.g. moisture content, biomass, fuel load) that modify fire susceptibility. The high human cost of fire and intimate mixing along the urban interface combine to modify the natural fire regime as well as provide additional impetus for a better understanding of how to predict fire and its management. Management problems have been further magnified by nearly seventy years of fire suppression and drought related die-back over the last few years resulting in a large accumulation of highly combustible fuels. Chaparral communities in the Santa Monica Mountains exemplify many of the management challenges associated with fire and biodiversity. A study was initiated in the Santa Monica Mountains to investigate the use of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) for providing improved maps of chaparral coupled with direct estimates of canopy attributes (e.g. biomass, leaf area, fuel load). The Santa Monica Mountains are an east-west trending range located approximately 75 kilometers north of Los Angeles extending westward into Ventura County. Within the Santa Monica Mountains a diverse number of ecosystems are located, including four distinct types of chaparral, wetlands, riparian habitats, woodlands, and coastal sage scrub. In this study we focus on mapping three types of chaparral, oak woodlands and grasslands. Chaparral mapped included coastal sage scrub, chamise chaparral and mixed chaparral that consisted predominantly of two species of Ceanothus.

Sleep and Movement Differentiates Actions of Two Types of Somatostatin-Expressing GABAergic Interneuron in Rat Hippocampus

PubMed Central

Katona, Linda; Lapray, Damien; Viney, Tim J.; Oulhaj, Abderrahim; Borhegyi, Zsolt; Micklem, Benjamin R.; Klausberger, Thomas; Somogyi, Peter

2014-01-01

Summary Neuropeptides acting on pre- and postsynaptic receptors are coreleased with GABA by interneurons including bistratified and O-LM cells, both expressing somatostatin but innervating segregated dendritic domains of pyramidal cells. Neuropeptide release requires high-frequency action potentials, but the firing patterns of most peptide/GABA-releasing interneurons during behavior are unknown. We show that behavioral and network states differentiate the activities of bistratified and O-LM cells in freely moving rats. Bistratified cells fire at higher rates during sleep than O-LM cells and, unlike O-LM cells, strongly increase spiking during sharp wave-associated ripples (SWRs). In contrast, O-LM interneurons decrease firing during sleep relative to awake states and are mostly inhibited during SWRs. During movement, both cell types fire cooperatively at the troughs of theta oscillations but with different frequencies. Somatostatin and GABA are differentially released to distinct dendritic zones of CA1 pyramidal cells during sleep and wakefulness to coordinate segregated glutamatergic inputs from entorhinal cortex and CA3. PMID:24794095

Distinct Developmental Origins Manifest in the Specialized Encoding of Movement by Adult Neurons of the External Globus Pallidus

PubMed Central

Dodson, Paul D.; Larvin, Joseph T.; Duffell, James M.; Garas, Farid N.; Doig, Natalie M.; Kessaris, Nicoletta; Duguid, Ian C.; Bogacz, Rafal; Butt, Simon J.B.; Magill, Peter J.

2015-01-01

Summary Transcriptional codes initiated during brain development are ultimately realized in adulthood as distinct cell types performing specialized roles in behavior. Focusing on the mouse external globus pallidus (GPe), we demonstrate that the potential contributions of two GABAergic GPe cell types to voluntary action are fated from early life to be distinct. Prototypic GPe neurons derive from the medial ganglionic eminence of the embryonic subpallium and express the transcription factor Nkx2-1. These neurons fire at high rates during alert rest, and encode movements through heterogeneous firing rate changes, with many neurons decreasing their activity. In contrast, arkypallidal GPe neurons originate from lateral/caudal ganglionic eminences, express the transcription factor FoxP2, fire at low rates during rest, and encode movements with robust increases in firing. We conclude that developmental diversity positions prototypic and arkypallidal neurons to fulfil distinct roles in behavior via their disparate regulation of GABA release onto different basal ganglia targets. PMID:25843402

Regulation of dopaminergic neuron firing by heterogeneous dopamine autoreceptors in the substantia nigra pars compacta.

PubMed

Jang, Jin Young; Jang, Miae; Kim, Shin Hye; Um, Ki Bum; Kang, Yun Kyung; Kim, Hyun Jin; Chung, Sungkwon; Park, Myoung Kyu

2011-03-01

Dopamine (DA) receptors generate many cellular signals and play various roles in locomotion, motivation, hormone production, and drug abuse. According to the location and expression types of the receptors in the brain, DA signals act in either stimulatory or inhibitory manners. Although DA autoreceptors in the substantia nigra pars compacta are known to regulate firing activity, the exact expression patterns and roles of DA autoreceptor types on the firing activity are highly debated. Therefore, we performed individual correlation studies between firing activity and receptor expression patterns using acutely isolated rat substantia nigra pars compacta DA neurons. When we performed single-cell RT-PCR experiments, D(1), D(2)S, D(2)L, D(3), and D(5) receptor mRNA were heterogeneously expressed in the order of D(2)L > D(2)S > D(3) > D(5) > D(1). Stimulation of D(2) receptors with quinpirole suppressed spontaneous firing similarly among all neurons expressing mRNA solely for D(2)S, D(2)L, or D(3) receptors. However, quinpirole most strongly suppressed spontaneous firing in the neurons expressing mRNA for both D(2) and D(3) receptors. These data suggest that D(2) S, D(2)L, and D(3) receptors are able to equally suppress firing activity, but that D(2) and D(3) receptors synergistically suppress firing. This diversity in DA autoreceptors could explain the various actions of DA in the brain. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

Fuel Consumption and Fire Emissions Estimates in Siberia: Impact of Vegetation Types, Meteorological Conditions, Forestry Practices and Fire Regimes

NASA Astrophysics Data System (ADS)

Kukavskaya, Elena; Conard, Susan; Ivanova, Galina; Buryak, Ludmila; Soja, Amber; Zhila, Sergey

2015-04-01

Boreal forests play a crucial role in carbon budgets with Siberian carbon fluxes and pools making a major contribution to the regional and global carbon cycle. Wildfire is the main ecological disturbance in Siberia that leads to changes in forest species composition and structure and in carbon storage, as well as direct emissions of greenhouse gases and aerosols to the atmosphere. At present, the global scientific community is highly interested in quantitative and accurate estimates of fire emissions. Little research on wildland fuel consumption and carbon emission estimates has been carried out in Russia until recently. From 2000 to 2007 we conducted a series of experimental fires of varying fireline intensity in light-coniferous forest of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions due to fires of known behavior. From 2009 to 2013 we examined a number of burned logged areas to assess the potential impact of forest practices on fire emissions. In 2013-2014 burned areas in dark-coniferous and deciduous forests were examined to determine fuel consumption and carbon emissions. We have combined and analyzed the scarce data available in the literature with data obtained in the course of our long-term research to determine the impact of various factors on fuel consumption and to develop models of carbon emissions for different ecosystems of Siberia. Carbon emissions varied drastically (from 0.5 to 40.9 tC/ha) as a function of vegetation type, weather conditions, anthropogenic effects and fire behavior characteristics and periodicity. Our study provides a basis for better understanding of the feedbacks between wildland fire emissions and changing anthropogenic disturbance patterns and climate. The data obtained could be used by air quality agencies to calculate local emissions and by managers to develop strategies to mitigate negative smoke impacts on the environmentand human health.

Conservation threats due to human-caused increases in fire frequency in Mediterranean-climate ecosystems.

PubMed

Syphard, Alexandra D; Radeloff, Volker C; Hawbaker, Todd J; Stewart, Susan I

2009-06-01

Periodic wildfire is an important natural process in Mediterranean-climate ecosystems, but increasing fire recurrence threatens the fragile ecology of these regions. Because most fires are human-caused, we investigated how human population patterns affect fire frequency. Prior research in California suggests the relationship between population density and fire frequency is not linear. There are few human ignitions in areas with low population density, so fire frequency is low. As population density increases, human ignitions and fire frequency also increase, but beyond a density threshold, the relationship becomes negative as fuels become sparser and fire suppression resources are concentrated. We tested whether this hypothesis also applies to the other Mediterranean-climate ecosystems of the world. We used global satellite databases of population, fire activity, and land cover to evaluate the spatial relationship between humans and fire in the world's five Mediterranean-climate ecosystems. Both the mean and median population densities were consistently and substantially higher in areas with than without fire, but fire again peaked at intermediate population densities, which suggests that the spatial relationship is complex and nonlinear. Some land-cover types burned more frequently than expected, but no systematic differences were observed across the five regions. The consistent association between higher population densities and fire suggests that regardless of differences between land-cover types, natural fire regimes, or overall population, the presence of people in Mediterranean-climate regions strongly affects the frequency of fires; thus, population growth in areas now sparsely settled presents a conservation concern. Considering the sensitivity of plant species to repeated burning and the global conservation significance of Mediterranean-climate ecosystems, conservation planning needs to consider the human influence on fire frequency. Fine-scale spatial analysis of relationships between people and fire may help identify areas where increases in fire frequency will threaten ecologically valuable areas. ©2009 Society for Conservation Biology.

Fire service instructor's undergarment choice to reduce Interleukin-6 and minimise physiological and perceptual strain.

PubMed

Watkins, Emily R; Richardson, Alan J

2017-01-01

Fire Service Instructors frequently experience high levels of physiological and perceptual strain during live fire exposures. Instructors are also at risk of cardiovascular illnesses, with cardiac death being the greatest cause of fire fighter death. Current practice for UK instructors is to select undergarment type based on personal preference, between a boiler suit (BOILER) and a wicking base layer (WBL). Research suggests that shorts and t-shirt (SHORTS) may also be a beneficial alternative undergarment choice. The UK South East Fire Service requested an investigation to identify if undergarment selection can lessen the strain experienced by instructors, and reduce the acute inflammatory response to fire exposures. Eight males completed three 45min sessions in a heat chamber (49.5±1.4°C and 16.9±4.3% RH) whilst performing intermittent walking. At the end of heat exposure change in heart rate was not effected by garment type (p=0.061, ηp 2 =0.373). Change in rectal temperature was different between garments (p=0.009, η p 2 =0.271), with trends suggesting that BOILER resulted in a greater change (1.03±0.60°C) than SHORTS (0.76±0.37°C, p=0.589, d=0.21) and WBL (0.72±0.33°C, p=0.545, d=0.25). Interleukin-6 post exposure was greater for BOILER (6.96±0.28pgmL -1 ) than both SHORTS (6.59±0.30pgmL -1 , p=0.043, d=0.42) and WBL (6.45±0.43pgmL -1 , p=0.031, d=0.51). Overall, undergarment type had little impact on physiological or perceptual strain. However, wearing WBL or SHORTS may reduce the inflammatory response, and consequently decrease the risk of cardiovascular events. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Modeling Forest Composition and Carbon Dynamics Under Projected Climate-Fire Interactions in the Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Liang, S.; Hurteau, M. D.; Westerling, A. L.

2014-12-01

The Sierra Nevada Mountains are occupied by a diversity of forest types that sort by elevation. The interaction of changing climate and altered disturbance regimes (e.g. fire) has the potential to drive changes in forest distribution as a function of species-specific response. Quantifying the effects of these drivers on species distributions and productivity under future climate-fire interactions is necessary for informing mitigation and adaptation efforts. In this study, we assimilated forest inventory and soil survey data and species life history traits into a landscape model, LANDIS-II, to quantify the response of forest dynamics to the interaction of climate change and large wildfire frequency in the Sierra Nevada. We ran 100-year simulations forced with historical climate and climate projections from three models (GFDL, CNRM and CCSM3) driven by the A2 emission scenario. We found that non-growing season NPP is greatly enhanced by 15%-150%, depending on the specific climate projection. The greatest increase occurs in subalpine forests. Species-specific response varied as a function of life history characteristics. The distribution of drought and fire-tolerant species, such as ponderosa pine, expanded by 7.3-9.6% from initial conditions, while drought and fire-intolerant species, such as white fir, showed little change in the absence of fire. Changes in wildfire size and frequency influence species distributions by altering the successional stage of burned patches. The range of responses to different climate models demonstrates the sensitivity of these forests to climate variability. The scale of climate projections relative to the scale of forest simulations presents a source of uncertainty, particularly at the ecotone between forest types and for identifying topographically mediated climate refugia. Improving simulations will likely require higher resolution climate projections.

Fire risk in California

NASA Astrophysics Data System (ADS)

Peterson, Seth Howard

Fire is an integral part of ecosystems in the western United States. Decades of fire suppression have led to (unnaturally) large accumulations of fuel in some forest communities, such as the lower elevation forests of the Sierra Nevada. Urban sprawl into fire prone chaparral vegetation in southern California has put human lives at risk and the decreased fire return intervals have put the vegetation community at risk of type conversion. This research examines the factors affecting fire risk in two of the dominant landscapes in the state of California, chaparral and inland coniferous forests. Live fuel moisture (LFM) is important for fire ignition, spread rate, and intensity in chaparral. LFM maps were generated for Los Angeles County by developing and then inverting robust cross-validated regression equations from time series field data and vegetation indices (VIs) and phenological metrics from MODIS data. Fire fuels, including understory fuels which are not visible to remote sensing instruments, were mapped in Yosemite National Park using the random forests decision tree algorithm and climatic, topographic, remotely sensed, and fire history variables. Combining the disparate data sources served to improve classification accuracies. The models were inverted to produce maps of fuel models and fuel amounts, and these showed that fire fuel amounts are highest in the low elevation forests that have been most affected by fire suppression impacting the natural fire regime. Wildland fires in chaparral commonly burn in late summer or fall when LFM is near its annual low, however, the Jesusita Fire burned in early May of 2009, when LFM was still relatively high. The HFire fire spread model was used to simulate the growth of the Jesusita Fire using LFM maps derived from imagery acquired at the time of the fire and imagery acquired in late August to determine how much different the fire would have been if it had occurred later in the year. Simulated fires were 1.5 times larger, and the fire reached the wildland urban interface three hours earlier, when using August LFM.

Fire history of the local wildland-urban interface

Treesearch

Neil R. Honeycutt

1995-01-01

Fire activity in Alameda and Contra Costa Counties has been recorded in historical documents. In pre-European times the Native Americans in the hills above the eastern shore of San Francisco Bay used fire to remove unwanted underbrush to improve the wildlife habitat. This type of "prescribed" burning may have been the earliest fire management in this region—...

Allocating resources to large wildland fires: a model with stochastic production rates

Treesearch

Romain Mees; David Strauss

1992-01-01

Wildland fires that grow out of the initial attack phase are responsible for most of the damage and burned area. We model the allocation of fire suppression resources (ground crews, engines, bulldozers, and airdrops) to these large fires. The fireline at a given future time is partitioned into homogeneous segments on the basis of fuel type, available resources, risk,...

Storm Prediction Center Product & Report Archives

Science.gov Websites

Current Watches Meso. Discussions Conv. Outlooks Tstm. Outlooks Fire Wx Outlooks XML logo RSS Feeds E-Mail Archived Fire Weather Outlooks To view fire weather outlooks for a previous day, type in the date you wish to retrieve (e.g. 140503 for May 3, 2014). Data available since June 4, 2002. 150101 Retrieve Fire

Forest landowner decisions and the value of information under fire risk.

Treesearch

Gregory S. Amacher; Arun S. Malik; Robert G. Haight

2005-01-01

We estimate the value of three types of information about fire risk to a nonindustrial forest landowner: the relationship between fire arrival rates and stand age, the magnitude of fire arrival rates, and the efficacy of fuel reduction treatment. Our model incorporates planting density and the level and timing of fuel reduction treatment as landowner decisions. These...

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...

A study of flame spread in engineered cardboard fuelbeds: Part II: Scaling law approach

Treesearch

Brittany A. Adam; Nelson K. Akafuah; Mark Finney; Jason Forthofer; Kozo Saito

2013-01-01

In this second part of a two part exploration of dynamic behavior observed in wildland fires, time scales differentiating convective and radiative heat transfer is further explored. Scaling laws for the two different types of heat transfer considered: Radiation-driven fire spread, and convection-driven fire spread, which can both occur during wildland fires. A new...

10 CFR Appendix R to Part 50 - Fire Protection Program for Nuclear Power Facilities Operating Prior to January 1, 1979

Code of Federal Regulations, 2010 CFR

2010-01-01

... could occur in a nuclear power plant. These sessions shall provide brigade members with experience in... A. Fire protection program. A fire protection program shall be established at each nuclear power... fires that could occur in the plant and in using the types of equipment available in the nuclear power...

MODIS-informed greenness responsesto daytime land surface temperaturefluctuations and wildfire disturbancesin the Alaskan Yukon River Basin

USGS Publications Warehouse

Tan, Zhengxi; Liu, Shu-Guang; Jenkerson, Calli B.; Oeding, Jennifer; Wylie, Bruce K.; Rover, Jennifer R.; Young, Claudia J.

2012-01-01

Pronounced climate warming and increased wildfire disturbances are known to modify forest composition and control the evolution of the boreal ecosystem over the Yukon River Basin (YRB) in interior Alaska. In this study, we evaluate the post-fire green-up rate using the normalized difference vegetation index (NDVI) derived from 250 m 7 day eMODIS (an alternative and application-ready type of Moderate Resolution Imaging Spectroradiometer (MODIS) data) acquired between 2000 and 2009. Our analyses indicate measureable effects on NDVI values from vegetation type, burn severity, post-fire time, and climatic variables. The NDVI observations from both fire scars and unburned areas across the Alaskan YRB showed a tendency of an earlier start to the growing season (GS); the annual variations in NDVI were significantly correlated to daytime land surface temperature (LST) fluctuations; and the rate of post-fire green-up depended mainly on burn severity and the time of post-fire succession. The higher average NDVI values for the study period in the fire scars than in the unburned areas between 1950 and 2000 suggest that wildfires enhance post-fire greenness due to an increase in post-fire evergreen and deciduous species components

The Elimination of Fire Hazard Due to Back Fires

NASA Technical Reports Server (NTRS)

Theodorsen, Theodore; Freeman, Ira M

1933-01-01

A critical study was made of the operation of a type of back-fire arrester used to reduce the fire hazard of aircraft engines. A flame arrester consisting of a pack or plug of alternate flat and corrugated plates of thin metal was installed in the intake pipe of a gasoline engines; an auxiliary spark plug inserted in the intake manifold permitted the production of artificial back fires at will. It was found possible to design a plug which prevented all back fires from reaching the carburetor.

46 CFR 28.825 - Excess fire detection and protection equipment.

Code of Federal Regulations, 2011 CFR

2011-10-01

...” “CARBON DIOXIDE FIRE SYSTEM” or “FOAM FIRE SYSTEM”, as the case may be; (v) Instructions for the operation... be locked, a key to the space or enclosure shall be in a break-glass-type box conspicuously located...

Prototypic and Arkypallidal Neurons in the Dopamine-Intact External Globus Pallidus

PubMed Central

Abdi, Azzedine; Mallet, Nicolas; Mohamed, Foad Y.; Sharott, Andrew; Dodson, Paul D.; Nakamura, Kouichi C.; Suri, Sana; Avery, Sophie V.; Larvin, Joseph T.; Garas, Farid N.; Garas, Shady N.; Vinciati, Federica; Morin, Stéphanie; Bezard, Erwan

2015-01-01

Studies in dopamine-depleted rats indicate that the external globus pallidus (GPe) contains two main types of GABAergic projection cell; so-called “prototypic” and “arkypallidal” neurons. Here, we used correlative anatomical and electrophysiological approaches in rats to determine whether and how this dichotomous organization applies to the dopamine-intact GPe. Prototypic neurons coexpressed the transcription factors Nkx2-1 and Lhx6, comprised approximately two-thirds of all GPe neurons, and were the major GPe cell type innervating the subthalamic nucleus (STN). In contrast, arkypallidal neurons expressed the transcription factor FoxP2, constituted just over one-fourth of GPe neurons, and innervated the striatum but not STN. In anesthetized dopamine-intact rats, molecularly identified prototypic neurons fired at relatively high rates and with high regularity, regardless of brain state (slow-wave activity or spontaneous activation). On average, arkypallidal neurons fired at lower rates and regularities than prototypic neurons, and the two cell types could be further distinguished by the temporal coupling of their firing to ongoing cortical oscillations. Complementing the activity differences observed in vivo, the autonomous firing of identified arkypallidal neurons in vitro was slower and more variable than that of prototypic neurons, which tallied with arkypallidal neurons displaying lower amplitudes of a “persistent” sodium current important for such pacemaking. Arkypallidal neurons also exhibited weaker driven and rebound firing compared with prototypic neurons. In conclusion, our data support the concept that a dichotomous functional organization, as actioned by arkypallidal and prototypic neurons with specialized molecular, structural, and physiological properties, is fundamental to the operations of the dopamine-intact GPe. PMID:25926446

Firefighter injuries are not just a fireground problem.

PubMed

Frost, D M; Beach, T A C; Crosby, I; McGill, S M

2015-01-01

Linking firefighter injury reporting to general motion patterns may provide insight into potential injury mechanisms and the development of prevention strategies. To characterize the injuries sustained by members of a large Canadian metropolitan fire department over a 5-year span. Data were taken from injury reports filed by career firefighters between 2007 and 2011. Injuries were described by job duty, type, body part affected, and the general motion pattern employed at the time of injury (e.g. lifting). Of the 1311 injuries reported, 64% were categorized as sprains and strains (musculoskeletal disorders -MSDs), the most frequent of which affected the back (32%). Categorized by job duty, 65% of MSDs were sustained while working at the fire station or during physical training-related activities. Only 15% were attributed to fireground operations. Furthermore, the associated job duty could not differentiate the types of injuries sustained; back injuries occurred primarily while lifting, knee injuries while stepping, and shoulder injuries during pushing/pulling-related activities. Firefighter injuries are not just a fireground problem. Injury causation may be better understood by linking the injury location and type with motion patterns rather than job duties. This information could assist in developing general prevention strategies for the fire service.

At the nexus of fire, water and society.

PubMed

Martin, Deborah A

2016-06-05

The societal risks of water scarcity and water-quality impairment have received considerable attention, evidenced by recent analyses of these topics by the 2030 Water Resources Group, the United Nations and the World Economic Forum. What are the effects of fire on the predicted water scarcity and declines in water quality? Drinking water supplies for humans, the emphasis of this exploration, are derived from several land cover types, including forests, grasslands and peatlands, which are vulnerable to fire. In the last two decades, fires have affected the water supply catchments of Denver (CO) and other southwestern US cities, and four major Australian cities including Sydney, Canberra, Adelaide and Melbourne. In the same time period, several, though not all, national, regional and global water assessments have included fire in evaluations of the risks that affect water supplies. The objective of this discussion is to explore the nexus of fire, water and society with the hope that a more explicit understanding of fire effects on water supplies will encourage the incorporation of fire into future assessments of water supplies, into the pyrogeography conceptual framework and into planning efforts directed at water resiliency.This article is part of the themed issue 'The interaction of fire and mankind'. © 2016 The Author(s).

LANDFIRE: Collaboration for National Fire Fuel Assessment

USGS Publications Warehouse

Zhu, Zhi-Liang

2006-01-01

The implementation of national fire management policies, such as the National Fire Plan and the Healthy Forest Restoration Act, requires geospatial data of vegetation types and structure, wildland fuels, fire risks, and ecosystem fire regime conditions. Presently, no such data sets are available that can meet these requirements. As a result, the U.S. Department of Agriculture (USDA) Forest Service and the Department of the Interior's land management bureaus (Bureau of Indian Affairs (BIA), Bureau of Land Management (BLM), Fish and Wildlife Service (FWS), and National Park Service (NPS)) have jointly sponsored LANDFIRE, a new research and development project. The primary objective of the project is to develop an integrated and repeatable methodology and produce vegetation, fire, and ecosystem information and predictive models for cost-effective national land management applications. The project is conducted collaboratively by the U.S. Geological Survey (USGS), the USDA Forest Service, and The Nature Conservancy.

Neural correlates for angular head velocity in the rat dorsal tegmental nucleus

NASA Technical Reports Server (NTRS)

Bassett, J. P.; Taube, J. S.; Oman, C. M. (Principal Investigator)

2001-01-01

Many neurons in the rat lateral mammillary nuclei (LMN) fire selectively in relation to the animal's head direction (HD) in the horizontal plane independent of the rat's location or behavior. One hypothesis of how this representation is generated and updated is via subcortical projections from the dorsal tegmental nucleus (DTN). Here we report the type of activity in DTN neurons. The majority of cells (75%) fired as a function of the rat's angular head velocity (AHV). Cells exhibited one of two types of firing patterns: (1) symmetric, in which the firing rate was positively correlated with AHV during head turns in both directions, and (2) asymmetric, in which the firing rate was positively correlated with head turns in one direction and correlated either negatively or not at all in the opposite direction. In addition to modulation by AHV, some of the AHV cells (40.1%) were weakly modulated by the rat's linear velocity, and a smaller number were modulated by HD (11%) or head pitch (15.9%). Autocorrelation analyses indicated that with the head stationary, AHV cells displayed irregular discharge patterns. Because afferents from the DTN are the major source of information projecting to the LMN, these results suggest that AHV information from the DTN plays a significant role in generating the HD signal in LMN. A model is proposed showing how DTN AHV cells can generate and update the LMN HD cell signal.

Thalamocortical neurons display suppressed burst-firing due to an enhanced Ih current in a genetic model of absence epilepsy.

PubMed

Cain, Stuart M; Tyson, John R; Jones, Karen L; Snutch, Terrance P

2015-06-01

Burst-firing in distinct subsets of thalamic relay (TR) neurons is thought to be a key requirement for the propagation of absence seizures. However, in the well-regarded Genetic Absence Epilepsy Rats from Strasbourg (GAERS) model as yet there has been no link described between burst-firing in TR neurons and spike-and-wave discharges (SWDs). GAERS ventrobasal (VB) neurons are a specific subset of TR neurons that do not normally display burst-firing during absence seizures in the GAERS model, and here, we assessed the underlying relationship of VB burst-firing with Ih and T-type calcium currents between GAERS and non-epileptic control (NEC) animals. In response to 200-ms hyperpolarizing current injections, adult epileptic but not pre-epileptic GAERS VB neurons displayed suppressed burst-firing compared to NEC. In response to longer duration 1,000-ms hyperpolarizing current injections, both pre-epileptic and epileptic GAERS VB neurons required significantly more hyperpolarizing current injection to burst-fire than those of NEC animals. The current density of the Hyperpolarization and Cyclic Nucleotide-activated (HCN) current (Ih) was found to be increased in GAERS VB neurons, and the blockade of Ih relieved the suppressed burst-firing in both pre-epileptic P15-P20 and adult animals. In support, levels of HCN-1 and HCN-3 isoform channel proteins were increased in GAERS VB thalamic tissue. T-type calcium channel whole-cell currents were found to be decreased in P7-P9 GAERS VB neurons, and also noted was a decrease in CaV3.1 mRNA and protein levels in adults. Z944, a potent T-type calcium channel blocker with anti-epileptic properties, completely abolished hyperpolarization-induced VB burst-firing in both NEC and GAERS VB neurons.

Relationship between leaf traits and fire-response strategies in shrub species of a mountainous region of south-eastern Australia.

PubMed

Vivian, Lyndsey M; Cary, Geoffrey J

2012-01-01

Resprouting and seed recruitment are important ways in which plants respond to fire. However, the investments a plant makes into ensuring the success of post-fire resprouting or seedling recruitment can result in trade-offs that are manifested in a range of co-occurring morphological, life history and physiological traits. Relationships between fire-response strategies and other traits have been widely examined in fire-prone Mediterranean-type climates. In this paper, we aim to determine whether shrubs growing in a non-Mediterranean climate region exhibit relationships between their fire-response strategy and leaf traits. Field surveys were used to classify species into fire-response types. We then compared specific leaf area, leaf dry-matter content, leaf width, leaf nitrogen and carbon to nitrogen ratios between (a) obligate seeders and all other resprouters, and (b) obligate seeders, facultative resprouters and obligate resprouters. Leaf traits only varied between fire-response types when we considered facultative resprouters as a separate group to obligate resprouters, as observed after a large landscape-scale fire. We found no differences between obligate seeders and obligate resprouters, nor between obligate seeders and resprouters considered as one group. The results suggest that facultative resprouters may require a strategy of rapid resource acquisition and fast growth in order to compete with species that either resprout, or recruit from seed. However, the overall lack of difference between obligate seeders and obligate resprouters suggests that environmental factors are exerting similar effects on species' ecological strategies, irrespective of the constraints and trade-offs that may be associated with obligate seeding and obligate resprouting. These results highlight the limits to trait co-occurrences across different ecosystems and the difficulty in identifying global-scale relationships amongst traits.

Relationship between leaf traits and fire-response strategies in shrub species of a mountainous region of south-eastern Australia

PubMed Central

Vivian, Lyndsey M.; Cary, Geoffrey J.

2012-01-01

Background and Aims Resprouting and seed recruitment are important ways in which plants respond to fire. However, the investments a plant makes into ensuring the success of post-fire resprouting or seedling recruitment can result in trade-offs that are manifested in a range of co-occurring morphological, life history and physiological traits. Relationships between fire-response strategies and other traits have been widely examined in fire-prone Mediterranean-type climates. In this paper, we aim to determine whether shrubs growing in a non-Mediterranean climate region exhibit relationships between their fire-response strategy and leaf traits. Methods Field surveys were used to classify species into fire-response types. We then compared specific leaf area, leaf dry-matter content, leaf width, leaf nitrogen and carbon to nitrogen ratios between (a) obligate seeders and all other resprouters, and (b) obligate seeders, facultative resprouters and obligate resprouters. Key Results Leaf traits only varied between fire-response types when we considered facultative resprouters as a separate group to obligate resprouters, as observed after a large landscape-scale fire. We found no differences between obligate seeders and obligate resprouters, nor between obligate seeders and resprouters considered as one group. Conclusions The results suggest that facultative resprouters may require a strategy of rapid resource acquisition and fast growth in order to compete with species that either resprout, or recruit from seed. However, the overall lack of difference between obligate seeders and obligate resprouters suggests that environmental factors are exerting similar effects on species' ecological strategies, irrespective of the constraints and trade-offs that may be associated with obligate seeding and obligate resprouting. These results highlight the limits to trait co-occurrences across different ecosystems and the difficulty in identifying global-scale relationships amongst traits. PMID:21994052

Management Impacts on Carbon Dynamics in a Sierra Nevada Mixed Conifer Forest

PubMed Central

Dore, Sabina; Fry, Danny L.; Collins, Brandon M.; Vargas, Rodrigo; York, Robert A.; Stephens, Scott L.

2016-01-01

Forest ecosystems can act as sinks of carbon and thus mitigate anthropogenic carbon emissions. When forests are actively managed, treatments can alter forests carbon dynamics, reducing their sink strength and switching them from sinks to sources of carbon. These effects are generally characterized by fast temporal dynamics. Hence this study monitored for over a decade the impacts of management practices commonly used to reduce fire hazards on the carbon dynamics of mixed-conifer forests in the Sierra Nevada, California, USA. Soil CO2 efflux, carbon pools (i.e. soil carbon, litter, fine roots, tree biomass), and radial tree growth were compared among un-manipulated controls, prescribed fire, thinning, thinning followed by fire, and two clear-cut harvested sites. Soil CO2 efflux was reduced by both fire and harvesting (ca. 15%). Soil carbon content (upper 15 cm) was not significantly changed by harvest or fire treatments. Fine root biomass was reduced by clear-cut harvest (60–70%) but not by fire, and the litter layer was reduced 80% by clear-cut harvest and 40% by fire. Thinning effects on tree growth and biomass were concentrated in the first year after treatments, whereas fire effects persisted over the seven-year post-treatment period. Over this period, tree radial growth was increased (25%) by thinning and reduced (12%) by fire. After seven years, tree biomass returned to pre-treatment levels in both fire and thinning treatments; however, biomass and productivity decreased 30%-40% compared to controls when thinning was combined with fire. The clear-cut treatment had the strongest impact, reducing ecosystem carbon stocks and delaying the capacity for carbon uptake. We conclude that post-treatment carbon dynamics and ecosystem recovery time varied with intensity and type of treatments. Consequently, management practices can be selected to minimize ecosystem carbon losses while increasing future carbon uptake, resilience to high severity fire, and climate related stresses. PMID:26918460

Birth wind and fire: raising awareness to operating room fires during delivery.

PubMed

Wolf, Omer; Weissman, Oren; Harats, Moti; Farber, Nimrod; Stavrou, Demetris; Tessone, Ariel; Zilinsky, Isaac; Winkler, Eyal; Haik, Josef

2013-09-01

We researched whether the obstetric operating room (OR) qualified as a fire-risk environment so as to take preventive measures accordingly. We analyzed a series of iatrogenic burns inflicted during birth by collecting clinical data and comparing it with known OR fire risk factors and with other factors that repeated in all cases in search of unique characteristics of the obstetric OR. All three cases shared in common the same type of oxygen-rich open ventilation system, alcohol-based prepping solution, and the hastiness of cesarean delivery while spontaneous vaginal delivery was already in progress. The obstetric OR is, as suspected, a fire-prone zone in more ways than the regular OR. Therefore, preventive measures should be undertaken and awareness for the possibility for such occurrences should be raised.

Sensory Regulation of Network Components Underlying Ciliary Locomotion in Hermissenda

PubMed Central

Crow, Terry; Tian, Lian-Ming

2008-01-01

Ciliary locomotion in the nudibranch mollusk Hermissenda is modulated by the visual and graviceptive systems. Components of the neural network mediating ciliary locomotion have been identified including aggregates of polysensory interneurons that receive monosynaptic input from identified photoreceptors and efferent neurons that activate cilia. Illumination produces an inhibition of type Ii (off-cell) spike activity, excitation of type Ie (on-cell) spike activity, decreased spike activity in type IIIi inhibitory interneurons, and increased spike activity of ciliary efferent neurons. Here we show that pairs of type Ii interneurons and pairs of type Ie interneurons are electrically coupled. Neither electrical coupling or synaptic connections were observed between Ie and Ii interneurons. Coupling is effective in synchronizing dark-adapted spontaneous firing between pairs of Ie and pairs of Ii interneurons. Out-of-phase burst activity, occasionally observed in dark-adapted and light-adapted pairs of Ie and Ii interneurons, suggests that they receive synaptic input from a common presynaptic source or sources. Rhythmic activity is typically not a characteristic of dark-adapted, light-adapted, or light-evoked firing of type I interneurons. However, burst activity in Ie and Ii interneurons may be elicited by electrical stimulation of pedal nerves or generated at the offset of light. Our results indicate that type I interneurons can support the generation of both rhythmic activity and changes in tonic firing depending on sensory input. This suggests that the neural network supporting ciliary locomotion may be multifunctional. However, consistent with the nonmuscular and nonrhythmic characteristics of visually modulated ciliary locomotion, type I interneurons exhibit changes in tonic activity evoked by illumination. PMID:18768639

Control of Phasic Firing by a Background Leak Current in Avian Forebrain Auditory Neurons

PubMed Central

Dagostin, André A.; Lovell, Peter V.; Hilscher, Markus M.; Mello, Claudio V.; Leão, Ricardo M.

2015-01-01

Central neurons express a variety of neuronal types and ion channels that promote firing heterogeneity among their distinct neuronal populations. Action potential (AP) phasic firing, produced by low-threshold voltage-activated potassium currents (VAKCs), is commonly observed in mammalian brainstem neurons involved in the processing of temporal properties of the acoustic information. The avian caudomedial nidopallium (NCM) is an auditory area analogous to portions of the mammalian auditory cortex that is involved in the perceptual discrimination and memorization of birdsong and shows complex responses to auditory stimuli We performed in vitro whole-cell patch-clamp recordings in brain slices from adult zebra finches (Taeniopygia guttata) and observed that half of NCM neurons fire APs phasically in response to membrane depolarizations, while the rest fire transiently or tonically. Phasic neurons fired APs faster and with more temporal precision than tonic and transient neurons. These neurons had similar membrane resting potentials, but phasic neurons had lower membrane input resistance and time constant. Surprisingly phasic neurons did not express low-threshold VAKCs, which curtailed firing in phasic mammalian brainstem neurons, having similar VAKCs to other NCM neurons. The phasic firing was determined not by VAKCs, but by the potassium background leak conductances, which was more prominently expressed in phasic neurons, a result corroborated by pharmacological, dynamic-clamp, and modeling experiments. These results reveal a new role for leak currents in generating firing diversity in central neurons. PMID:26696830

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.

Modeling the Effects of Drought, Fire, Beetles, and Management on Future Carbon Cycling in the Western US

NASA Astrophysics Data System (ADS)

Buotte, P.; Law, B. E.; Hicke, J. A.; Hudiburg, T. W.; Levis, S.; Kent, J.

2017-12-01

Fire and beetle outbreaks can have substantial impacts on forest structure, composition, and function and these types of disturbances are expected to increase in the future. Therefore understanding the ecological impacts of these disturbances into the future is important. We used ecosystem process modeling to estimate the future occurrence of fire and beetle outbreaks and their impacts on forest resilience and carbon sequestration. We modified the Community Land Model (CLM4.5) to better represent forest growth and mortality in the western US through multiple avenues: 1) we increased the ecological resolution to recognize 14 forest types common to the region; 2) we improved CLM4.5's ability to handle drought stress by adding forest type-specific controls on stomatal conductance and increased rates of leaf shed during periods of low soil moisture; 3) we developed and implemented a mechanistic model of beetle population growth and subsequent tree mortality; 4) we modified the current fire module to account for more refined forest types; and 5) we developed multiple scenarios of harvest based on past harvest rates and proposed changes in land management policies. We ran CLM4.5 in offline mode with climate forcing data. We compare future forest growth rates and carbon sequestration with historical metrics to estimate the combined influence of future disturbances on forest composition and carbon sequestration in the western US.

Calibration and validation of the relative differenced Normalized Burn Ratio (RdNBR) to three measures of fire severity in the Sierra Nevada and Klamath Mountains, California, USA

USGS Publications Warehouse

Miller, J.D.; Knapp, E.E.; Key, C.H.; Skinner, C.N.; Isbell, C.J.; Creasy, R.M.; Sherlock, J.W.

2009-01-01

Multispectral satellite data have become a common tool used in the mapping of wildland fire effects. Fire severity, defined as the degree to which a site has been altered, is often the variable mapped. The Normalized Burn Ratio (NBR) used in an absolute difference change detection protocol (dNBR), has become the remote sensing method of choice for US Federal land management agencies to map fire severity due to wildland fire. However, absolute differenced vegetation indices are correlated to the pre-fire chlorophyll content of the vegetation occurring within the fire perimeter. Normalizing dNBR to produce a relativized dNBR (RdNBR) removes the biasing effect of the pre-fire condition. Employing RdNBR hypothetically allows creating categorical classifications using the same thresholds for fires occurring in similar vegetation types without acquiring additional calibration field data on each fire. In this paper we tested this hypothesis by developing thresholds on random training datasets, and then comparing accuracies for (1) fires that occurred within the same geographic region as the training dataset and in similar vegetation, and (2) fires from a different geographic region that is climatically and floristically similar to the training dataset region but supports more complex vegetation structure. We additionally compared map accuracies for three measures of fire severity: the composite burn index (CBI), percent change in tree canopy cover, and percent change in tree basal area. User's and producer's accuracies were highest for the most severe categories, ranging from 70.7% to 89.1%. Accuracies of the moderate fire severity category for measures describing effects only to trees (percent change in canopy cover and basal area) indicated that the classifications were generally not much better than random. Accuracies of the moderate category for the CBI classifications were somewhat better, averaging in the 50%-60% range. These results underscore the difficulty in isolating fire effects to individual vegetation strata when fire effects are mixed. We conclude that the models presented here and in Miller and Thode ([Miller, J.D. & Thode, A.E., (2007). Quantifying burn severity in a heterogeneous landscape with a relative version of the delta Normalized Burn Ratio (dNBR). Remote Sensing of Environment, 109, 66-80.]) can produce fire severity classifications (using either CBI, or percent change in canopy cover or basal area) that are of similar accuracy in fires not used in the original calibration process, at least in conifer dominated vegetation types in Mediterranean-climate California.

Effect of ecosystem type and fire on chemistry of WEOM as measured by LDI-TOF-MS and NMR.

PubMed

Crecelius, Anna C; Vitz, Jürgen; Näthe, Kerstin; Meyer, Stefanie; Michalzik, Beate; Schubert, Ulrich S

2017-01-01

Soil organic matter (SOM) and its water-soluble components play an important role in terrestrial carbon cycling and associated ecosystem functions. Chemically, they are complex mixtures of organic compounds derived from decomposing plant material, microbial residues, as well as root exudates, and soil biota. To test the effect of the ecosystem type (forest and grassland) and fires events on the chemistry of dissolved organic matter (DOM), we applied a combination of laser-desorption/ionization time-of-flight mass spectrometry (LDI-TOF-MS) and 2D ( 1 H and 13 C) nuclear magnetic resonance (NMR) spectroscopy to water-extractable organic matter (WEOM) from a range of top soil samples. The aim was to assess the suitability of LDI-TOF-MS for the rapid characterization of WEOM. Therefore, we evaluated the effects of sample (pH and dilution) conditions and use of positive or negative reflector mode to identify the conditions under which LDI-TOF-MS best distinguished between WEOM from different sources. Thirty-six samples were measured with both analytical techniques and their chemical patterns were statistically evaluated to distinguish firstly the effect of the type of ecosystem (forest versus grassland) on WEOM characteristics, and secondly the impact of fire on the chemical composition of WEOM. The nonmetric multidimensional scaling (NMDS) analysis of the most suitable experimental LDI-TOF-MS conditions showed a clear separation between the type of vegetation and fire-induced changes, mostly reflecting the presence of poly(ethylene glycol) in grassland soils. Discrimination among WEOM from different vegetation types was preserved in the fire treated samples. The calculation of the relative abundance of certain functional structures in the WEOM samples revealed a common composition of forest and grassland WEOM, with polysaccharides and proteins making up to 60%. The compositional impact of forest fire on WEOM was more pronounced compared to the one of grassland, leading to a decline in the main components, and an increase in amino-sugars, fatty acids, and sterols. The recorded 1 H NMR and heteronuclear single quantum coherence (HSQC) spectra showed a decrease of the carbohydrate signal in WEOM from fire-treated samples, which was more pronounced in forest than in grassland soils. Copyright © 2016 Elsevier B.V. All rights reserved.

Fires: Pushing the Reset Button or a Flash in the Pan?

NASA Astrophysics Data System (ADS)

MacDonald, L. H.; Wagenbrenner, J. W.; Robichaud, P. R.; Nelson, P. A.; Kampf, S. K.; Brogan, D. J.

2016-12-01

High and moderate severity wildfires can reduce infiltration rates to less than 10 mm/hr, and the resulting surface runoff can increase small-scale peak flows by one or more orders of magnitude. Fires can increase hillslope erosion rates by several orders of magnitude, but this increase is less linear with rainfall intensity because it also depends on sediment supply and detachment processes as well as transport capacity. These localized and shorter-term effects have been relatively well documented, but there is much more uncertainty in how these fire-induced changes can lead to larger-scale and/or longer-term effects. The goal of this presentation is to provide a process-based analysis of how, where, and when wildfires can cause either longer-term or larger-scale changes, effectively resetting the system as opposed to a more transient "flash in the pan". An understanding of vegetation, climatic, and geomorphic dynamics are are critical for predicting larger-scale and longer-term effects. First is the potential for the vegetation to return to pre-fire conditions, and this depends on vegetation type, spatial extent of the fire, and if the pre-fire vegetation is marginalized by climate change, land use, or other factors. The trajectory of post-fire regrowth controls the duration of increased runoff and erosion as well as the size and severity of future fires, which then sets the scene for longer-term hydrologic and geomorphic change. Climate defines the dominant storm type and how they match up with the spatial extent of a fire. Historic data help estimate the extent and magnitude of post-fire rainfall, but there is a strong stochastic component and the more extreme events are of greatest concern. Geomorphic controls on larger-scale effects include the valley and drainage network characteristics that help govern the storage and delivery of water and sediment. Assessing each component involves multiple site factors, but the biggest problem is understanding their complex interactions to predict resource impacts, landscape change over different temporal and spatial scales, and the potential to ameliorate adverse impacts. Data from multiple field studies are used to illustrate the range of post-fire effects, selected interactions of the different components, and identify key research needs.

L-type calcium channels refine the neural population code of sound level

PubMed Central

Grimsley, Calum Alex; Green, David Brian

2016-01-01

The coding of sound level by ensembles of neurons improves the accuracy with which listeners identify how loud a sound is. In the auditory system, the rate at which neurons fire in response to changes in sound level is shaped by local networks. Voltage-gated conductances alter local output by regulating neuronal firing, but their role in modulating responses to sound level is unclear. We tested the effects of L-type calcium channels (CaL: CaV1.1–1.4) on sound-level coding in the central nucleus of the inferior colliculus (ICC) in the auditory midbrain. We characterized the contribution of CaL to the total calcium current in brain slices and then examined its effects on rate-level functions (RLFs) in vivo using single-unit recordings in awake mice. CaL is a high-threshold current and comprises ∼50% of the total calcium current in ICC neurons. In vivo, CaL activates at sound levels that evoke high firing rates. In RLFs that increase monotonically with sound level, CaL boosts spike rates at high sound levels and increases the maximum firing rate achieved. In different populations of RLFs that change nonmonotonically with sound level, CaL either suppresses or enhances firing at sound levels that evoke maximum firing. CaL multiplies the gain of monotonic RLFs with dynamic range and divides the gain of nonmonotonic RLFs with the width of the RLF. These results suggest that a single broad class of calcium channels activates enhancing and suppressing local circuits to regulate the sensitivity of neuronal populations to sound level. PMID:27605536

Characterizing interactions between fire and other disturbances and their impacts on tree mortality in western U.S. Forests

USGS Publications Warehouse

Kane, Jeffrey M.; Varner, J. Morgan; Metz, Margaret R.; van Mantgem, Phillip J.

2017-01-01

Increasing evidence that pervasive warming trends are altering disturbance regimes and their interactions with fire has generated substantial interest and debate over the implications of these changes. Previous work has primarily focused on conditions that promote non-additive interactions of linked and compounded disturbances, but the spectrum of potential interaction patterns has not been fully considered. Here we develop and define terminology, expand on the existing conceptual framework and review the patterns and mechanisms of disturbance interactions with a focus on interactions between fire and other forest disturbances and a specific emphasis on resulting tree mortality. The types of interactions reflect the positive, negative, or neutral responses to the incidence, intensity, and effects of the interaction. These types of interactions are not always mutually exclusive, but can be distinct. The collective effect of the interactions will determine the longer-term ecosystem response that can result in a resistant, resilient, or compounded interaction. Our review indicates that the interactions of drought, bark beetles, or pathogens with fire often result in neutral or maintained interactions that do not negatively or positively influence the incidence or intensity following fire. The effect of these disturbance interactions on tree mortality ranged from antagonistic (reduced mortality compared to individual disturbances) to synergistic (greater mortality compared to individual disturbances) within and among disturbance interaction types but often resulted in additive effects (mortality is consistent with the summation of the two disturbances). Synergistic effects on tree mortality have been observed when the severity of the initial disturbance is moderate to high and time between disturbances is relatively short. When the sequence of disturbance interaction is reversed (e.g., fire precedes other disturbances) the conditions can generally promote impeded interactions (lower incidence of interaction), reduced interactions (lower intensity of interaction), and antagonistic interactions (lower tree mortality). While recent research on fire-disturbance interactions has increased over the last decade and provided important insights, more research that identifies the specific thresholds of incidence, intensity, and effects of interaction by region and forest type are needed to better assist management solutions that promote desired outcomes in rapidly changing ecosystems.

Only multi-taxon studies show the full range of arthropod responses to fire

PubMed Central

Pryke, James S.; Gaigher, René; Samways, Michael J.

2018-01-01

Fire is a major driver in many ecosystems. Yet, little is known about how different ground-living arthropods survive fire. Using three sampling methods, and time-since-fire (last fire event: 3 months, 1 year, and 7 years), we investigate how ground-living arthropod diversity responds to fire, and how species richness, diversity, abundance, and composition of the four dominant taxa: ants, beetles, cockroaches and mites, respond. We did this in the naturally fire-prone Mediterranean-type scrubland vegetation (fynbos) of the Cape Floristic Region. Surprisingly, overall species richness and diversity was the same for all time-since-fire categories. However, when each dominant taxon was analysed separately, effect of fire on species richness and abundance varied among taxa. This emphasizes that many taxa must be investigated to really understand fire-driven events. We also highlight the importance of using different diversity measures, as fire did not influence species richness and abundance of particular taxa, while it affected others, overall greatly affecting assemblages of all taxa. Rockiness affected species richness, abundance and composition of a few taxa. We found that all time-since-fire categories supported distinctive assemblages. Some indicator species occurred across all time-since-fire categories, while others were restricted to a single time-since-fire category, showing that there is a wide range of responses to fire between taxa. Details of local landscape structure, abiotic and biotic, and frequency and intensity of fire add complexity to the fire-arthropod interaction. Overall, we show that the relationship between fire and arthropods is phylogenetically constrained, having been honed by many millennia of fire events, and highly complex. Present-day species manifest a variety of adaptations for surviving the great natural selective force of fire. PMID:29614132

Integration of vegetation community spatial data into a prescribed fire planning process at Shenandoah National Park, Virginia (USA)

USGS Publications Warehouse

Young, John A.; Mahan, Carolyn G.; Forder, Melissa

2017-01-01

Many eastern forest communities depend on fire for regeneration or are enhanced by fire as a restoration practice. However, the use of prescribed fire in the mesic forested environments and the densely populated regions of the eastern United States has been limited. The objective of our research was to develop a science-based approach to prioritizing the use of prescribed fire in appropriate forest types in the eastern United States based on a set of desired management outcomes. Through a process of expert elicitation and data analysis, we assessed and integrated recent vegetation community mapping results along with other available spatial data layers into a spatial prioritization tool for prescribed fire planning at Shenandoah National Park (Virginia, USA). The integration of vegetation spatial data allowed for development of per-pixel priority rankings and exclusion areas enabling precise targeting of fire management activities on the ground, as well as a park-wide ranking of fire planning compartments. We demonstrate the use and evaluation of this approach through implementation and monitoring of a prescribed burn and show that progress is being made toward desired conditions. Integration of spatial data into the fire planning process has served as a collaborative tool for the implementation of prescribed fire projects, which assures projects will be planned in the most appropriate areas to meet objectives that are supported by current science.

An approach of surface coal fire detection from ASTER and Landsat-8 thermal data: Jharia coal field, India

NASA Astrophysics Data System (ADS)

Roy, Priyom; Guha, Arindam; Kumar, K. Vinod

2015-07-01

Radiant temperature images from thermal remote sensing sensors are used to delineate surface coal fires, by deriving a cut-off temperature to separate coal-fire from non-fire pixels. Temperature contrast of coal fire and background elements (rocks and vegetation etc.) controls this cut-off temperature. This contrast varies across the coal field, as it is influenced by variability of associated rock types, proportion of vegetation cover and intensity of coal fires etc. We have delineated coal fires from background, based on separation in data clusters in maximum v/s mean radiant temperature (13th band of ASTER and 10th band of Landsat-8) scatter-plot, derived using randomly distributed homogeneous pixel-blocks (9 × 9 pixels for ASTER and 27 × 27 pixels for Landsat-8), covering the entire coal bearing geological formation. It is seen that, for both the datasets, overall temperature variability of background and fires can be addressed using this regional cut-off. However, the summer time ASTER data could not delineate fire pixels for one specific mine (Bhulanbararee) as opposed to the winter time Landsat-8 data. The contrast of radiant temperature of fire and background terrain elements, specific to this mine, is different from the regional contrast of fire and background, during summer. This is due to the higher solar heating of background rocky outcrops, thus, reducing their temperature contrast with fire. The specific cut-off temperature determined for this mine, to extract this fire, differs from the regional cut-off. This is derived by reducing the pixel-block size of the temperature data. It is seen that, summer-time ASTER image is useful for fire detection but required additional processing to determine a local threshold, along with the regional threshold to capture all the fires. However, the winter Landsat-8 data was better for fire detection with a regional threshold.

33 CFR 145.05 - Classification of fire extinguishers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Classification of fire... SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES FIRE-FIGHTING EQUIPMENT § 145.05 Classification of....05(c)—Portable and Semiportable Extinguishers Classification Type Size Soda-acid and water, gallons...

Particulate Matter Emissions for Fires in the Palmetto-Gallberry Fuel Type

Treesearch

Darold E. Ward

1983-01-01

Fire management specialists in the southeastern United States needing guides for predicting or assessing particulate matter emission factors, emission rates, and heat release rate can use the models presented in this paper for making these predictions as a function of flame length in the palmetto-gallberry fuel type.

The performance of lightweight plastic foams developed for fire safety

NASA Technical Reports Server (NTRS)

Fish, R. H.

1971-01-01

The use of a low density, polyurethane based foam to suppress a fire and to provide protection for the structure of an aircraft or spacecraft is discussed. The mechanism by which foams provide protection from heat and create a nonflammable surface is described. Various materials and their application to specific types of structures are examined.

Sensitivity of ALOS/PALSAR imagery to forest degradation by fire in northern Amazon

NASA Astrophysics Data System (ADS)

Martins, Flora da Silva Ramos Vieira; dos Santos, João Roberto; Galvão, Lênio Soares; Xaud, Haron Abrahim Magalhães

2016-07-01

We evaluated the sensitivity of the full polarimetric Phased Array type L-band Synthetic Aperture Radar (PALSAR), onboard the Advanced Land Observing Satellite (ALOS), to forest degradation caused by fires in northern Amazon, Brazil. We searched for changes in PALSAR signal and tri-dimensional polarimetric responses for different classes of fire disturbance defined by fire frequency and severity. Since the aboveground biomass (AGB) is affected by fire, multiple regression models to estimate AGB were obtained for the whole set of coherent and incoherent attributes (general model) and for each set separately (specific models). The results showed that the polarimetric L-band PALSAR attributes were sensitive to variations in canopy structure and AGB caused by forest fire. However, except for the unburned and thrice burned classes, no single PALSAR attribute was able to discriminate between the intermediate classes of forest degradation by fire. Both the coherent and incoherent polarimetric attributes were important to explain AGB variations in tropical forests affected by fire. The HV backscattering coefficient, anisotropy, double-bounce component, orientation angle, volume index and HH-VV phase difference were PALSAR attributes selected from multiple regression analysis to estimate AGB. The general regression model, combining phase and power radar metrics, presented better results than specific models using coherent or incoherent attributes. The polarimetric responses indicated the dominance of VV-oriented backscattering in primary forest and lightly burned forests. The HH-oriented backscattering predominated in heavily and frequently burned forests. The results suggested a greater contribution of horizontally arranged constituents such as fallen trunks or branches in areas severely affected by fire.

14 CFR 29.807 - Passenger emergency exits.

Code of Federal Regulations, 2014 CFR

2014-01-01

... inches wide by 48 inches high, with corner radii not greater than one-third the width of the exit, in the... might become potential fire hazards in a crash. (2) Type II. This type is the same as Type I, except that the opening must be at least 20 inches wide by 44 inches high. (3) Type III. This type is the same...

14 CFR 29.807 - Passenger emergency exits.

Code of Federal Regulations, 2013 CFR

2013-01-01

... inches wide by 48 inches high, with corner radii not greater than one-third the width of the exit, in the... might become potential fire hazards in a crash. (2) Type II. This type is the same as Type I, except that the opening must be at least 20 inches wide by 44 inches high. (3) Type III. This type is the same...

14 CFR 29.807 - Passenger emergency exits.

Code of Federal Regulations, 2012 CFR

2012-01-01

... inches wide by 48 inches high, with corner radii not greater than one-third the width of the exit, in the... might become potential fire hazards in a crash. (2) Type II. This type is the same as Type I, except that the opening must be at least 20 inches wide by 44 inches high. (3) Type III. This type is the same...

14 CFR 29.807 - Passenger emergency exits.

Code of Federal Regulations, 2010 CFR

2010-01-01

... inches wide by 48 inches high, with corner radii not greater than one-third the width of the exit, in the... might become potential fire hazards in a crash. (2) Type II. This type is the same as Type I, except that the opening must be at least 20 inches wide by 44 inches high. (3) Type III. This type is the same...

Surface Albedo Darkening from wildfires in Northern Sub-Saharan Africa

NASA Technical Reports Server (NTRS)

Gatebe, C. K.; Ichoku, C. M.; Poudal, R.; Roman, M. O.; Wilcox, E.

2014-01-01

Wildfires are recognized as a key physical disturbance of terrestrial ecosystems and a major source of atmospheric trace gases and aerosols. They are known to produce changes in landscape patterns and lead to changes in surface albedo that can persist for long periods. Here, we estimate the darkening of surface albedo due to wildfires in different land cover ecosystems in the Northern Sub-Saharan Africa using data from the Moderate Resolution Imaging Spectroradiometer (MODIS). We determined a decrease in albedo after fires over most land cover types (e.g. woody savannas: (-0.00352 0.00003) and savannas: (- 0.003910.00003), which together accounted for >86% of the total MODIS fire count between 2003 and 2011). Grasslands had a higher value (-0.00454 0.00003) than the savannas, but accounted for only about 5% of the total fire count. A few other land cover types (e.g. Deciduous broad leaf: (0.00062 0.00015), and barren: 0.00027 0.00019), showed an increase in albedo after fires, but accounted for less than 1% of the total fires. Albedo change due to wildfires is more important during the fire season (October-February). The albedo recovery progresses rapidly during the first year after fires, where savannas show the greatest recovery (>77%) within one year, while deciduous broadleaf, permanent wetlands and barren lands show the least one-year recovery (56%). The persistence of surface albedo darkening in most land cover types is limited to about six to seven years, after which at least 98% of the burnt pixels recover to their pre-fire albedo.

46 CFR 160.028-2 - Type.

Code of Federal Regulations, 2010 CFR

2010-10-01

... of the center-firing type having chamber and bore dimensions within the limits indicated by Figure No... section may have any chamber and bore dimensions if they are not the dimensions for a conventional round...

46 CFR 160.028-2 - Type.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of the center-firing type having chamber and bore dimensions within the limits indicated by Figure No... section may have any chamber and bore dimensions if they are not the dimensions for a conventional round...

46 CFR 160.028-2 - Type.

Code of Federal Regulations, 2014 CFR

2014-10-01

... of the center-firing type having chamber and bore dimensions within the limits indicated by Figure No... section may have any chamber and bore dimensions if they are not the dimensions for a conventional round...

46 CFR 160.028-2 - Type.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of the center-firing type having chamber and bore dimensions within the limits indicated by Figure No... section may have any chamber and bore dimensions if they are not the dimensions for a conventional round...

46 CFR 160.028-2 - Type.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of the center-firing type having chamber and bore dimensions within the limits indicated by Figure No... section may have any chamber and bore dimensions if they are not the dimensions for a conventional round...

Weather types and the regime of wildfires in Portugal

NASA Astrophysics Data System (ADS)

Pereira, M. G.; Trigo, R. M.; Dacamara, C. C.

2009-04-01

An objective classification scheme, as developed by Trigo and DaCamara (2000), was applied to classify the daily atmospheric circulation affecting Portugal between 1980 and 2007 into a set of 10 basic weather types (WTs). The classification scheme relies on a set of atmospheric circulation indices, namely southerly flow (SF), westerly flow (WF), total flow (F), southerly shear vorticity (ZS), westerly shear vorticity (ZW) and total vorticity (Z). The weather-typing approach, together with surfacemeteorological variables (e.g. intensity and direction of geostrophic wind, maximum and minimum temperature and precipitation) were then associated to wildfire events as recorded in the official Portuguese fire database consisting of information on each fire occurred in the 18 districts of Continental Portugal within the same period (>450.000 events). The objective of this study is to explore the dependence of wildfire activity on weather and climate and then evaluate the potential of WTs to discriminate among recorded wildfires on what respects to their occurrence and development. Results show that days characterised by surface flow with an eastern component (i.e. NE, E and SE) account for a high percentage of daily burnt area, as opposed to surface westerly flow (NW, W and SW), which represents about a quarter of the total number of days but only accounts for a very low percentage of active fires and of burnt area. Meteorological variables such as minimum and maximum temperatures, that are closely associated to surface wind intensity and direction, also present a good ability to discriminate between the different types of fire events.. Trigo R.M., DaCamara C. (2000) "Circulation Weather Types and their impact on the precipitation regime in Portugal". Int J of Climatology, 20, 1559-1581.

[Clinical manifestations related to kitchen biomass smoke in African women].

PubMed

Kouassi, B; Horo, K; Ahui, B; Godé, C; N'Guessan, L; Anon, J-C; Koffi, N; Ngom, A; Aka-Danguy, E; Koffi, M O; Djè Bi, I H; Ano, A

2012-03-01

Fires of wood and charcoal play an essential part in the cooking of food in Africa. These fires emit thick smoke that has definite health consequences. To determine the clinical manifestations related to kitchen smoke and to identify the type of fire most often incriminated. It was a transverse study comparing the clinical features in women using three types of fire: wood, charcoal and gas. We questioned 200 women in each group who used one type of fire exclusively for five days a week for at least five years. Clinical manifestations associated with the smoke were reported in all the women using wood as opposed to 98.5% using charcoal and 45.5% using gas. More than 80% had physical signs. These comprised 89.1% upper respiratory and 77% pulmonary signs. Upper respiratory signs were the most common, mainly sneezing and nasal obstruction. At the pulmonary level, a predominance of signs was found in women using wood fires (47.3%) and charcoal (36.2%), the difference being statistically significant. The signs included chronic cough, chest pain and dyspnoea. Wheezes were found in 15% of the women. Cooking smoke exposes women to complications which are most frequently associated with the use of wood or charcoal. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Predictions of fire behavior and resistance to control: for use with photo series for the sierra mixed conifer type and the sierra true fir type.

Treesearch

Franklin R. Ward; David V. Sandberg

1981-01-01

This publication presents tables on the behavior of fire and the resistance: of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Sierra Mixed Conifer Type, Sierra True Fir Type" (Maxwell, Wayne G.; Ward, Franklin R. 1979. Gen. Tech. Rep. PNW-GTR-095. Portland, OR: U.S....

Increasing resiliency in frequent fire forests: Lessons from the Sierra Nevada and western Australia

Treesearch

Scott L. Stephens

2014-01-01

This paper will primarily focus on the management and restoration of forests adapted to frequent, low-moderate intensity fire regimes. These are the forest types that are most at risk from large, high-severity wildfires and in many regions their fire regimes are changing. Fire as a landscape process can exhibit self-limiting characteristics in some forests which can...

Fire behavior in masticated fuels: a review

Treesearch

Jesse K. Kreye; Nolan W. Brewer; Penelope Morgan; J. Morgan Varner; Alistair M.S. Smith; Chad M. Hoffman; Roger D. Ottmar

2014-01-01

Mastication is an increasingly common fuels treatment that redistributes ‘‘ladder’’ fuels to the forest floor to reduce vertical fuel continuity, crown fire potential, and fireline intensity, but fuel models do not exist for predicting fire behavior in these fuel types. Recent fires burning in masticated fuels have behaved in unexpected and contradictory ways, likely...

Pezizalean mycorrhizas and sporocarps in ponderosa pine (Pinus ponderosa) after prescribed fires in eastern Oregon, USA.

Treesearch

K.E. Fujimura; J.E. Smith; T.R. Horton; N.S. Weber; J.W. Spatafora

2005-01-01

Post-fire Pezizales fruit commonly in many forest types after fire. The objectives of this study were to determine which Pezizales appeared as sporocarps after a prescribed fire in the Blue Mountains of eastern Oregon, and whether species of Pezizales formed mycorrhizas on ponderosa pine, whether or not they were detected from sporocarps. Forty-two sporocarp...

Chemical and dispersal characteristics of particulate emissions from forest fires in Siberia

Treesearch

Y. N. Samsonov; V. A. Ivanov; D. J. McRae; S. P. Baker

2012-01-01

Approximately 20 experimental fires were conducted on forest plots of 1-4 ha each in 2000-07 in two types of boreal forests in central Siberia, and 18 on 6 x 12-m plots in 2008-10. These experiments were designed to mimic wildfires under similar burning conditions. The fires were conducted in prescribed conditions including full documentation on pre-fire weather, pre-...

Evaluation of weapons' combustion products in armored vehicles. Appendix C: Summary of descriptive statistics (proc tabulate). Appendix D: Summary of comparative statistics. Final report, 30 September 1986-14 December 1988

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

Menzies, K.T.; Randel, M.A.; Quill, A.L.

1989-01-01

The U.S. Army Biomedical Research and Development Laboratory defined an extensive research program to address the generation of potentially toxic propellant combustion products in crew compartments of armored vehicles during weapons firing. The major objectives of the research were (1) to determine the presence and concentration of propellant combustion products, (2) to determine potential crew exposure to these combustion products, and (3) to assess the efficacy of field monitoring in armored vehicles. To achieve these goals, air monitoring was conducted in selected armored vehicle types, i.e., M109, M60, M3, M1, at several Army installations. Auxiliary information concerning the specific munitionsmore » fired and the Training and Doctrine Command (TRADOC) or Forces Command (FORSCOM) firing scenarios was collected so that a comparison of pollutant concentrations generated by specific weapons both within vehicle types and between vehicle types could be made.« less

Experimental gas-fired pulse-combustion studies

NASA Technical Reports Server (NTRS)

Blomquist, C. A.

1982-01-01

Experimental studies conducted at Argonne National Laboratory on a gas-fired, water-cooled, Helmholtz-type pulse combustion burner are discussed. In addition to the experimental work, information is presented on the evolution of pulse combustion, the types of pulse combustion burners and their applications, and the types of fuels used. Also included is a survey of other pertinent studies of gas-fired pulse combustion. The burner used in the Argonne research effort was equipped with adjustable air and gas flapper valves and was operated stably over a heat-input range of 30,000 to 200,000 Btu/h. The burner's overall heat transfer in the pulsating mode was 22 to 31% higher than when the unit was operated in the steady mode. Important phenomena discussed include (1) effects on performance produced by inserting a corebustor to change tailpipe diameter, (2) effects observed following addition of an air-inlet decoupling chamber to the unit, and (3) occurrence of carbon monoxide in the exhaust gas.

Fire as the dominant driver of central Canadian boreal forest carbon balance.

PubMed

Bond-Lamberty, Ben; Peckham, Scott D; Ahl, Douglas E; Gower, Stith T

2007-11-01

Changes in climate, atmospheric carbon dioxide concentration and fire regimes have been occurring for decades in the global boreal forest, with future climate change likely to increase fire frequency--the primary disturbance agent in most boreal forests. Previous attempts to assess quantitatively the effect of changing environmental conditions on the net boreal forest carbon balance have not taken into account the competition between different vegetation types on a large scale. Here we use a process model with three competing vascular and non-vascular vegetation types to examine the effects of climate, carbon dioxide concentrations and fire disturbance on net biome production, net primary production and vegetation dominance in 100 Mha of Canadian boreal forest. We find that the carbon balance of this region was driven by changes in fire disturbance from 1948 to 2005. Climate changes affected the variability, but not the mean, of the landscape carbon balance, with precipitation exerting a more significant effect than temperature. We show that more frequent and larger fires in the late twentieth century resulted in deciduous trees and mosses increasing production at the expense of coniferous trees. Our model did not however exhibit the increases in total forest net primary production that have been inferred from satellite data. We find that poor soil drainage decreased the variability of the landscape carbon balance, which suggests that increased climate and hydrological changes have the potential to affect disproportionately the carbon dynamics of these areas. Overall, we conclude that direct ecophysiological changes resulting from global climate change have not yet been felt in this large boreal region. Variations in the landscape carbon balance and vegetation dominance have so far been driven largely by increases in fire frequency.

Global Change Impacts on Future Fire Regimes: Distinguishing Between Climate-limited vs Ignition-Limited Landscapes

NASA Astrophysics Data System (ADS)

Keeley, J. E.; Syphard, A. D.

2016-12-01

Global warming is expected to exacerbate fire impacts. Predicting how climates will impact future fire regimes requires an understanding of how temperature and precipitation interact to control fire activity. Inevitably this requires historical analyses that relate annual burning to climate variation. Within climatically homogeneous subregions, montane forested landscapes show strong relationships between annual fluctuations in temperature and precipitation with area burned, however, this is strongly seasonal dependent; e.g., winter temperatures have very little or no effect but spring and summer temperatures are critical. Climate models are needed that predict future seasonal temperature changes if we are to forecast future fire regimes in these forests. Climate does not appear to be a major determinant of fire activity on all landscapes. Lower elevations and lower latitudes show little or no increase in fire activity with hotter and drier conditions. On these landscapes climate is not usually limiting to fires but these vegetation types are ignition-limited, and because they are closely juxtaposed with human habitations fire regimes are more strongly controlled by other direct anthropogenic impacts. Predicting future fire regimes is not rocket science, it is far more complicated than that. Climate change is not relevant on some landscapes, but where climate is relevant the relationship will change due to direct climate effects on vegetation trajectories, as well as by feedback processes of fire effects on vegetation distribution, plus policy changes in how we manage ecosystems.

The 1977 tundra fire at Kokolik River, Alaska

NASA Technical Reports Server (NTRS)

Hall, D.; Brown, J.; Johnson, L.

1981-01-01

During the summer of 1977, fire totaled 44 sq km of tundra vegetation according to measurements using LANDSAT imagery. Based on the experience gained from analysis of this fire using ground observations, satellite imagery, and topographic maps, it appears that natural drainages form effective fire breaks on the subdued relief of the Arctic coastal plain and northern foothills. It is confirmed that the intensity of the fire is related to vegetation type and to the moisture content of the organic rich soils.

Application of a Mesoscale Atmospheric Coupled Fire Model BRAMS-FIRE to Alentejo Woodland Fire and Comparison of Performance with the Fire Model WRF-Sfire.

NASA Astrophysics Data System (ADS)

Freitas, S. R.; Menezes, I. C.; Stockler, R.; Mello, R.; Ribeiro, N. A.; Corte-Real, J. A. M.; Surový, P.

2014-12-01

Models of fuel with the identification of vegetation patterns of Montado ecosystem in Portugal was incorporated in the mesoscale Brazilian Atmospheric Modeling System (BRAMS) and coupled with a spread woodland fire model. The BRAMS-FIRE is a new system developed by the "Centro de Previsão de Tempo e Estudos Climáticos" (CPTEC/INPE, Brazil) and the "Instituto de Ciências Agrárias e Ambientais Mediterrâneas" (ICAAM, Portugal). The fire model used in this effort was originally, developed by Mandel et al. (2013) and further incorporated in the Weather Research and Forecast model (WRF). Two grids of high spatial resolution were configured with surface input data and fuel models integrated for simulations using both models BRAMS-FIRE and WRF-SFIRE. One grid was placed in the plain land near Beja and the other one in the hills of Ossa to evaluate different types of fire propagation and calibrate BRAMS-FIRE. The objective is simulating the effects of atmospheric circulation in local scale, namely the movements of the heat front and energy release associated to it, obtained by this two models in an episode of woodland fire which took place in Alentejo area in the last decade, for application to planning and evaluations of agro woodland fire risks. We aim to model the behavior of forest fires through a set of equations whose solutions provide quantitative values of one or more variables related to the propagation of fire, described by semi-empirical expressions that are complemented by experimental data allow to obtain the main variables related advancing the perimeter of the fire, as the propagation speed, the intensity of the fire front and fuel consumption and its interaction with atmospheric dynamic system. References Mandel, J., J. D. Beezley, G. Kelman, A. K. Kochanski, V. Y. Kondratenko, B. H. Lynn, and M. Vejmelka, 2013. New features in WRF-SFIRE and the wildfire forecasting and danger system in Israel. Natural Hazards and Earth System Sciences, submitted, Numerical Wildfires, Cargèse, France, May 13-18, 2013.

An operational system for the assimilation of satellite information on wild-land fires for the needs of air quality modelling and forecasting

NASA Astrophysics Data System (ADS)

Sofiev, M.; Vankevich, R.; Lanne, M.; Prank, M.; Petukhov, V.; Ermakova, T.; Kukkonen, J.

2009-03-01

This paper investigates a potential of two remotely sensed wild-land fire characteristics: 4-μm Brightness Temperature Anomaly (TA) and Fire Radiative Power (FRP) for the needs of operational chemical transport modelling and the short-term forecasting of the atmospheric composition and air quality. Two treatments of the TA and FRP data are presented and a methodology for evaluating the emission fluxes is described. The method does not contain a complicated analysis of vegetation state, fuel load, burning efficiency and related factors, which are comparatively uncertain but inevitably involved in approaches based on burnt-area scars or similar products. The core of the current methodology is based on the empirical emission factors that have been derived from the analysis of several fire episodes in Europe (28 April-5 May 2006, 15-25 August 2006, August 2008 etc.). These episodes were characterised by: (i) well-identified FRP and TA values, and (ii) available independent observations of aerosol concentrations and optical thickness for the regions where fire smoke was dominant in comparison with contributions of other pollution sources. The emission factors were determined separately for the forested and grassland areas; in case of mixed-type land use an intermediate scaling was assumed. Despite significant difference between the TA and FRP products, an accurate non-linear fitting between the approaches was found. The agreement was comparatively weak only for small fires where the accuracy of both products is low. The re-analysis and forecasting applications of the Fire Assimilation System (FAS) showed that both TA and FRP products are suitable for evaluation of the emission fluxes from the wild-land fires. The concentrations of aerosols predicted by the regional dispersion modelling system SILAM appear within a factor of 2-3 from observations. The main areas of improvement include further refining the emission factors over the globe, explicit determination and appropriate treatment of the type of fires, evaluation of the injection height of the plumes and predicting the fire temporal evolution.

Alien plant dynamics following fire in mediterranean-climate California shrublands

USGS Publications Warehouse

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

2005-01-01

Over 75 species of alien plants were recorded during the first five years after fire in southern California shrublands, most of which were European annuals. Both cover and richness of aliens varied between years and plant association. Alien cover was lowest in the first postfire year in all plant associations and remained low during succession in chaparral but increased in sage scrub. Alien cover and richness were significantly correlated with year (time since disturbance) and with precipitation in both coastal and interior sage scrub associations. Hypothesized factors determining alien dominance were tested with structural equation modeling. Models that included nitrogen deposition and distance from the coast were not significant, but with those variables removed we obtained a significant model that gave an R2 = 0.60 for the response variable of fifth year alien dominance. Factors directly affecting alien dominance were (1) woody canopy closure and (2) alien seed banks. Significant indirect effects were (3) fire intensity, (4) fire history, (5) prefire stand structure, (6) aridity, and (7) community type. According to this model the most critical factor influencing aliens is the rapid return of the shrub and subshrub canopy. Thus, in these communities a single functional type (woody plants) appears to the most critical element controlling alien invasion and persistence. Fire history is an important indirect factor because it affects both prefire stand structure and postfire alien seed banks. Despite being fire-prone ecosystems, these shrublands are not adapted to fire per se, but rather to a particular fire regime. Alterations in the fire regime produce a very different selective environment, and high fire frequency changes the selective regime to favor aliens. This study does not support the widely held belief that prescription burning is a viable management practice for controlling alien species on semiarid landscapes. ?? 2005 by the Ecological Society of America.

27 CFR 555.209 - Construction of type 3 magazines.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Construction of type 3 magazines. A type 3 magazine is a “day-box” or other portable magazine. It must be fire...-type hardboard. Doors must overlap sides by at least one inch. Hinges and hasps are to be attached by welding, riveting or bolting (nuts on inside). One steel padlock (which need not be protected by a steel...

27 CFR 555.209 - Construction of type 3 magazines.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Construction of type 3 magazines. A type 3 magazine is a “day-box” or other portable magazine. It must be fire...-type hardboard. Doors must overlap sides by at least one inch. Hinges and hasps are to be attached by welding, riveting or bolting (nuts on inside). One steel padlock (which need not be protected by a steel...

Noise in Attractor Networks in the Brain Produced by Graded Firing Rate Representations

PubMed Central

Webb, Tristan J.; Rolls, Edmund T.; Deco, Gustavo; Feng, Jianfeng

2011-01-01

Representations in the cortex are often distributed with graded firing rates in the neuronal populations. The firing rate probability distribution of each neuron to a set of stimuli is often exponential or gamma. In processes in the brain, such as decision-making, that are influenced by the noise produced by the close to random spike timings of each neuron for a given mean rate, the noise with this graded type of representation may be larger than with the binary firing rate distribution that is usually investigated. In integrate-and-fire simulations of an attractor decision-making network, we show that the noise is indeed greater for a given sparseness of the representation for graded, exponential, than for binary firing rate distributions. The greater noise was measured by faster escaping times from the spontaneous firing rate state when the decision cues are applied, and this corresponds to faster decision or reaction times. The greater noise was also evident as less stability of the spontaneous firing state before the decision cues are applied. The implication is that spiking-related noise will continue to be a factor that influences processes such as decision-making, signal detection, short-term memory, and memory recall even with the quite large networks found in the cerebral cortex. In these networks there are several thousand recurrent collateral synapses onto each neuron. The greater noise with graded firing rate distributions has the advantage that it can increase the speed of operation of cortical circuitry. PMID:21931607

Wood Usage and Fire Veneration in the Pamir, Xinjiang, 2500 yr BP.

PubMed

Shen, Hui; Wu, Xinhua; Tang, Zihua; Zhou, Xinying; Sun, Nan; Li, Xiaoqiang

2015-01-01

Located on the Pamir Plateau in Xinjiang Province, China, the Ji'erzankale Necropolis dates back to 2500 yr BP. Many materials that have been unearthed in this cemetery, including shoo konghou (musical instrument), bronze mirrors and glass beads, suggest cultural transference between East and West. Furthermore, small-sized and rounded fire altars made from sweet-scented Sabina were found for the first time and regarded as implements for fire veneration. We identified 70 wooden objects from 25 tombs within the Necropolis, and found that each object had been made from one of seven tree species. Analysis revealed that the inhabitants of the region mainly used the most widely available types of wood, namely Betula and Populus. People also specifically chose inflammable Populus wood to make hearth boards and hand drills (both are used for making fire by drilling), rigid Betula wood to craft wooden plates. Salix was used for fashioning wooden sticks, while sweet-scented Sabina was the preferred choice for making fire altars. Lonicera was selected for arrow shaft manufacture and Fraxinus syriaca, which has a beautiful grain, was chosen for making musical instruments. Conscious selection of different types of wood indicates that people of the Pamir Plateau were aware of the properties of various types of timbers, and were able to exploit these properties to the full. In turn, this demonstrates their wisdom and their ability to survive in, and adapt to, their local environment.

Wood Usage and Fire Veneration in the Pamir, Xinjiang, 2500 yr BP

PubMed Central

Shen, Hui; Wu, Xinhua; Tang, Zihua; Zhou, Xinying; Sun, Nan; Li, Xiaoqiang

2015-01-01

Located on the Pamir Plateau in Xinjiang Province, China, the Ji’erzankale Necropolis dates back to 2500 yr BP. Many materials that have been unearthed in this cemetery, including shoo konghou (musical instrument), bronze mirrors and glass beads, suggest cultural transference between East and West. Furthermore, small-sized and rounded fire altars made from sweet-scented Sabina were found for the first time and regarded as implements for fire veneration. We identified 70 wooden objects from 25 tombs within the Necropolis, and found that each object had been made from one of seven tree species. Analysis revealed that the inhabitants of the region mainly used the most widely available types of wood, namely Betula and Populus. People also specifically chose inflammable Populus wood to make hearth boards and hand drills (both are used for making fire by drilling), rigid Betula wood to craft wooden plates. Salix was used for fashioning wooden sticks, while sweet-scented Sabina was the preferred choice for making fire altars. Lonicera was selected for arrow shaft manufacture and Fraxinus syriaca, which has a beautiful grain, was chosen for making musical instruments. Conscious selection of different types of wood indicates that people of the Pamir Plateau were aware of the properties of various types of timbers, and were able to exploit these properties to the full. In turn, this demonstrates their wisdom and their ability to survive in, and adapt to, their local environment. PMID:26308646

77 FR 21961 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-12

... the responses of California and Colorado residents to different scenarios related to fire hazard... researchers provide better information to natural resources, forest, and fire managers when they are contemplating the kind and type of fire hazard reduction programs to implement to achieve forest land management...

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

Fire is one of the most critical factors of disturbance in worldwide ecosystems. The effects of fires on soil, plants, landscape and ecosystems depend on many factors, among them fire frequency, fire severity and plant resistance. The characterization of vegetation post-fire behaviour is a fundamental issue to model and evaluate the fire resilience, which the ability of vegetation to recover after fire. Recent changes in fire regime, due to abandonment of local land use practice and climate change, can induce significant variations in vegetation fire resilience. In the Mediterranean-type communities, post fire vegetation trends have been analysed in a wide range of habitats, although pre- and post-fire investigation has been widely performed at stand level. But, factors controlling regeneration at the landscape scale are less well known. In this study, a time series of normalized difference vegetation index (NDVI) data derived from SPOT-VEGETATION was used to examine the recovery characteristics of fire affected vegetation in some test areas of the Mediterranean ecosystems of Southern Italy. The vegetation indices operate by contrasting intense chlorophyll pigment absorption in the red against the high reflectance of leaf mesophyll in the near infrared. SPOT-VEGETATION Normalized Difference Vegetation Index (NDVI) data from 1998 to 2005 were analyzed in order to evaluate the resilient effects in a some significant test sites of southern Italy. In particular, we considered: (i) one stable area site, one site affected by one fire during the investigated time window, (iii) one site affected by two consecutive fires during the investigated time window. In order to eliminate the phenological fluctuations, for each decadal composition of each pixel, we focused on the departure NDVId = [NDVI - ]/, where is the decadal mean and  is the decadal standard deviation. The decadal mean and the standard deviation were calculated for each decade, e.g. 1st 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.

Vegetation fire proneness in Europe

NASA Astrophysics Data System (ADS)

Pereira, Mário; Aranha, José; Amraoui, Malik

2015-04-01

Fire selectivity has been studied for vegetation classes in terms of fire frequency and fire size in a few European regions. This analysis is often performed along with other landscape variables such as topography, distance to roads and towns. These studies aims to assess the landscape sensitivity to forest fires in peri-urban areas and land cover changes, to define landscape management guidelines and policies based on the relationships between landscape and fires in the Mediterranean region. Therefore, the objectives of this study includes the: (i) analysis of the spatial and temporal variability statistics within Europe; and, (ii) the identification and characterization of the vegetated land cover classes affected by fires; and, (iii) to propose a fire proneness index. The datasets used in the present study comprises: Corine Land Cover (CLC) maps for 2000 and 2006 (CLC2000, CLC2006) and burned area (BA) perimeters, from 2000 to 2013 in Europe, provided by the European Forest Fire Information System (EFFIS). The CLC is a part of the European Commission programme to COoRdinate INformation on the Environment (Corine) and it provides consistent, reliable and comparable information on land cover across Europe. Both the CLC and EFFIS datasets were combined using geostatistics and Geographical Information System (GIS) techniques to access the spatial and temporal evolution of the types of shrubs and forest affected by fires. Obtained results confirms the usefulness and efficiency of the land cover classification scheme and fire proneness index which allows to quantify and to compare the propensity of vegetation classes and countries to fire. As expected, differences between northern and southern Europe are notorious in what concern to land cover distribution, fire incidence and fire proneness of vegetation cover classes. This work was supported by national funds by FCT - Portuguese Foundation for Science and Technology, under the project PEst-OE/AGR/UI4033/2014 and by the project SUSTAINSYS: Environmental Sustainable Agro-Forestry Systems (NORTE-07-0124-FEDER-000044), financed by the North Portugal Regional Operational Programme (ON.2 - O Novo Norte), under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER), as well as by National Funds (PIDDAC) through the Portuguese Foundation for Science and Technology (FCT/MEC).

Defining pyromes and global syndromes of fire regimes.

PubMed

Archibald, Sally; Lehmann, Caroline E R; Gómez-Dans, Jose L; Bradstock, Ross A

2013-04-16

Fire is a ubiquitous component of the Earth system that is poorly understood. To date, a global-scale understanding of fire is largely limited to the annual extent of burning as detected by satellites. This is problematic because fire is multidimensional, and focus on a single metric belies its complexity and importance within the Earth system. To address this, we identified five key characteristics of fire regimes--size, frequency, intensity, season, and extent--and combined new and existing global datasets to represent each. We assessed how these global fire regime characteristics are related to patterns of climate, vegetation (biomes), and human activity. Cross-correlations demonstrate that only certain combinations of fire characteristics are possible, reflecting fundamental constraints in the types of fire regimes that can exist. A Bayesian clustering algorithm identified five global syndromes of fire regimes, or pyromes. Four pyromes represent distinctions between crown, litter, and grass-fueled fires, and the relationship of these to biomes and climate are not deterministic. Pyromes were partially discriminated on the basis of available moisture and rainfall seasonality. Human impacts also affected pyromes and are globally apparent as the driver of a fifth and unique pyrome that represents human-engineered modifications to fire characteristics. Differing biomes and climates may be represented within the same pyrome, implying that pathways of change in future fire regimes in response to changes in climate and human activity may be difficult to predict.