Short-term effect of fuel treatments on fire behaviour in a mixed heathland: a comparative assessment in an outdoor wind tunnel

2014 ◽  
Vol 23 (8) ◽  
pp. 1097 ◽  
Author(s):  
Eva Marino ◽  
Carmen Hernando ◽  
Javier Madrigal ◽  
Mercedes Guijarro
Keyword(s):  
Wind Tunnel ◽  
Prescribed Burning ◽  
Flame Height ◽  
Fuel Load ◽  
Fire Intensity ◽  
Fuel Management ◽  
Fire Behaviour ◽  
Fuel Treatments ◽  
Relevant Effect ◽  
Significant Difference

Fuel management is one of the main challenges for wildfire prevention in the Mediterranean region, where wildfires have important environmental and socioeconomic effects. Different treatments are usually applied in fire-prone shrubland to try to modify its flammability. However, a knowledge gap on the effectiveness of fuel management techniques still exists. We studied the effects of two mechanical treatments (shrub crushing and shrub clearing with removal) and of prescribed burning, on fire behaviour, and compared them with untreated vegetation. Experimental burns in 0.8 × 6 m samples of regenerated shrubs 2 years after treatments were performed in an outdoor wind tunnel. All fuel treatments effectively modified fire behaviour, but no significant difference between treatment types was observed. Shrub fuel structure was the main factor affecting fire behaviour. Reduction of fuel load and height, especially necromass fraction, decreased flame height and fire intensity but did not affect fire rate of spread. Moisture contents of live and dead fuel fractions were not significant as independent parameters, but the average moisture level of the shrub fuel complex showed a relevant effect in determining fire behaviour. Temperature regime within and above the shrubs was also related to shrub fuel structure. This study contributes to understanding fuel management in shrubland by providing information about different fuel treatments effects on fire behaviour.

Fuel and fire characteristics in savanna - woodland of West Africa in relation to grazing and dominant grass type

2007 ◽  
Vol 16 (5) ◽  
pp. 531 ◽  
Author(s):  
Patrice Savadogo ◽  
Didier Zida ◽  
Louis Sawadogo ◽  
Daniel Tiveau ◽  
Mulualem Tigabu ◽  
...  
Keyword(s):  
Prescribed Burning ◽  
Management Tool ◽  
Fuel Load ◽  
Maximum Temperature ◽  
Fire Intensity ◽  
Fire Behaviour ◽  
Savanna Woodland ◽  
Vegetation Height ◽  
Average Maximum ◽  
Dominant Grass

Fuel characteristics, fire behaviour and temperature were studied in relation to grazing, dominant grass type and wind direction in West African savanna–woodland by lighting 32 prescribed early fires. Grazing significantly reduced the vegetation height, total fuel load, and dead and live fuel fractions whereas plots dominated by perennial grasses had higher values for vegetation height, total fuel load and the quantity of live fuel load. Although fire intensity remained insensitive (P > 0.05) to any of these factors, fuel consumption was significantly (P = 0.021) reduced by grazing, rate of spread was faster in head fire (P = 0.012), and flame length was shorter in head fire than back fire (P = 0.044). The average maximum temperature was higher (P < 0.05) on non-grazed plots, on plots dominated by annual grasses, on plots subjected to head fire, and at the soil surface. Lethal temperature residence time showed a nearly similar trend to fire temperature. Wind speed and total fuel load were best predictors of fire behaviour parameters (R2 ranging from 0.557 to 0.862). It can be concluded that grazing could be used as a management tool to modify fire behaviour, back fire should be carried out during prescribed burning to lower fire severity, and the fire behaviour models can be employed to guide prescribed early fire in the study area.

Does season affect fire behaviour in the Cerrado?

2017 ◽  
Vol 26 (5) ◽  
pp. 427 ◽  
Author(s):  
Mariana Ninno Rissi ◽  
M. Jaime Baeza ◽  
Elizabeth Gorgone-Barbosa ◽  
Talita Zupo ◽  
Alessandra Fidelis
Keyword(s):  
Dry Season ◽  
Flame Height ◽  
Fuel Load ◽  
Fire Season ◽  
Fire Intensity ◽  
Fire Behaviour ◽  
Dead Biomass ◽  
Management Plans ◽  
Fire Exclusion ◽  
Fuel Moisture Content

Fire has played an important role in the plant dynamics and diversity of the Cerrado for millions of years. We evaluated fire behaviour in different fire seasons in areas of an open savanna, providing information for fire management plans. It has been hypothesised that early fires (May – end of the rainy season) will be less intense than those conducted in the middle and end of the dry season (July and October) owing to the amount of dead biomass accumulated. Therefore, we compared fire behaviour in early, mid- and late dry season, evaluating the main fire and environmental variables. Fire intensity was mainly influenced by the combination of dead fuel percentage and fuel load. Even though this combination was the best model to explain fire intensity variability, fire parameters (including fire intensity) did not differ between fire seasons. Flame height was best explained by dead fuel percentage + fuel moisture content, dead fuel percentage + fuel load and also by dead fuel percentage. Our study showed that, in areas with fire exclusion for 2 years, fire season did not influence fire parameters and fire behaviour and the main factors influencing fire intensity were the proportion of dead biomass and total fuel load.

Simulating the effectiveness of prescribed burning at altering wildfire behaviour in Tasmania, Australia

2018 ◽  
Vol 27 (1) ◽  
pp. 15 ◽  
Author(s):  
James M. Furlaud ◽  
Grant J. Williamson ◽  
David M. J. S. Bowman
Keyword(s):  
Prescribed Burning ◽  
Vegetation Type ◽  
Weather Conditions ◽  
Statistical Modelling ◽  
Fire Intensity ◽  
Fire Weather ◽  
Fire Behaviour ◽  
Large Area ◽  
Treatment Scenario ◽  
Wildfire Hazard

Prescribed burning is a widely accepted wildfire hazard reduction technique; however, knowledge of its effectiveness remains limited. To address this, we employ simulations of a widely used fire behaviour model across the ecologically diverse Australian island state of Tasmania. We simulate three broad scenarios: (1) no fuel treatment, (2) a maximal treatment, with the most possible prescribed burning within ecological constraints, and (3) 12 hypothetically more implementable state-wide prescribed-burning plans. In all simulations, we standardised fire-weather inputs to represent regionally typical dangerous fire-weather conditions. Statistical modelling showed that an unrealistically large maximal treatment scenario could reduce fire intensity in three flammable vegetation types, and reduce fire probability in almost every vegetation type. However, leverage analysis of the 12 more-realistic implementable plans indicated that such prescribed burning would have only a minimal effect, if any, on fire extent and that none of these prescribed-burning plans substantially reduced fire intensity. The study highlights that prescribed burning can theoretically mitigate wildfire, but that an unrealistically large area would need to be treated to affect fire behaviour across the island. Rather, optimisation of prescribed burning requires careful landscape design at the local scale. Such designs should be based on improved fire behaviour modelling, empirical measurement of fuels and analysis of actual wildfires.

Got to burn to learn: the effect of fuel load on grassland fire behaviour and its management implications

2018 ◽  
Vol 27 (11) ◽  
pp. 727 ◽  
Author(s):  
Miguel G. Cruz ◽  
Andrew L. Sullivan ◽  
James S. Gould ◽  
Richard J. Hurley ◽  
Matt P. Plucinski
Keyword(s):  
Fire Spread ◽  
Flame Height ◽  
Fuel Load ◽  
Limiting Factor ◽  
Fire Behaviour ◽  
Load Effect ◽  
Fire Propagation ◽  
Rate Of Spread ◽  
Eastern Australia ◽  
Modelling Assumptions

The effect of grass fuel load on fire behaviour and fire danger has been a contentious issue for some time in Australia. Existing operational models have placed different emphases on the effect of fuel load on model outputs, which has created uncertainty in the operational assessment of fire potential and has led to end-user and public distrust of model outcomes. A field-based experimental burning program was conducted to quantify the effect of fuel load on headfire rate of spread and other fire behaviour characteristics in grasslands. A total of 58 experimental fires conducted at six sites across eastern Australia were analysed. We found an inverse relationship between fuel load and the rate of spread in grasslands, which is contrary to current, untested, modelling assumptions. This result is valid for grasslands where fuel load is not a limiting factor for fire propagation. We discuss the reasons for this effect and model it to produce a fuel load effect function that can be applied to operational grassfire spread models used in Australia. We also analyse the effect of fuel load on flame characteristics and develop a model for flame height as a function of rate of fire spread and fuel load.

scholarly journals AVALIAÇÃO DE ESPÉCIES ARBÓREAS PARA COMPOSIÇÃO DE CORTINAS DE SEGURANÇA CONTRA INCÊNDIOS FLORESTAIS

Nativa ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 197
Author(s):  
Bruna Kovalsyki ◽  
Luiz Donizeti Casimiro Junior ◽  
Rafaela Assunção ◽  
Raquel Costa Chiao Travenisk ◽  
Alexandre França Tetto ◽  
...  
Keyword(s):  
Tree Species ◽  
Flame Height ◽  
Fuel Load ◽  
Fire Intensity ◽  
Forest Protection ◽  
Magnolia Grandiflora ◽  
Viburnum Odoratissimum ◽  
Casearia Sylvestris ◽  
Michelia Champaca ◽  
Bougainvillea Glabra

Cortina de segurança é um plantio em faixas com espécies vegetais de menor combustibilidade do que as do cultivo principal, a fim de reduzir ou evitar a propagação do fogo. O presente trabalho teve por objetivo avaliar o potencial das espécies Magnolia grandiflora L., Michelia champaca L., Viburnum odoratissimum Ker Gawl., Casearia sylvestris Swartz e Bougainvillea glabra Choisy para compor cortinas de segurança. Para isso, as espécies foram analisadas em função do teor de umidade, altura de chama, velocidade de propagação do fogo, quantidade de material combustível consumido em queimas experimentais e intensidade do fogo. Foram realizadas 10 repetições por espécie e as queimas foram realizadas no Laboratório de Incêndios Florestais, do Departamento de Ciências Florestais, da Universidade Federal do Paraná, em parcelas de 1 m², com uma carga de 1 kg de material combustível fino seco em estufa. As espécies que se destacaram nas análises foram B. glabra e C. sylvestris, as quais indicaram baixa combustibilidade, apresentando assim potencial para uso em cortina de segurança na prevenção de incêndios florestais.Palavras-chave: barreiras verdes, prevenção de incêndios, altura de chama, proteção florestal. EVALUATION OF TREE SPECIES FOR THE COMPOSITION OF GREEN FIREBREAKS AGAINST FOREST FIRES ABSTRACT: Green firebreaks are vegetation stripes with a lower combustibility than that of the main crop and are intended to prevent or restrict the spread of fire. The present study aimed to evaluate the potential of the following tree species to compose firebreaks: Magnolia grandiflora L., Michelia champaca L., Viburnum odoratissimum Ker Gawl., Casearia sylvestris Swartz and Bougainvillea glabra Choisy. The species were analyzed according to their moisture content, flame height, fire spread rate, amount of fuel consumed in controlled burns, and fire intensity. There were ten repetitions per species and the burns were done at the wildfire laboratory, from the forest sciences department, of Universidade Federal do Paraná, on experimental plots of 1 m2, with 1 kg of thin fuel load, kiln-dried at 75 °C for 48 hours. The most notable species from the analyses were B. glabra and C. sylvestris, which indicated low combustibility, showing potential to compose green firebreaks and prevent forest fires.Keywords: green firebreaks, fire prevention, flame height, forest protection.

scholarly journals The impact of aging on laboratory fire behaviour in masticated shrub fuelbeds of California and Oregon, USA

2016 ◽  
Vol 25 (9) ◽  
pp. 1002 ◽  
Author(s):  
Jesse K. Kreye ◽  
J. Morgan Varner ◽  
Jeffrey M. Kane ◽  
Eric E. Knapp ◽  
Warren P. Reed
Keyword(s):  
Tree Mortality ◽  
Management Practice ◽  
Fire Hazard ◽  
Woody Debris ◽  
Fuel Load ◽  
Fire Intensity ◽  
Fire Behaviour ◽  
Slow Combustion ◽  
The Impact ◽  
Over Time

Mastication of shrubs and small trees to reduce fire hazard has become a widespread management practice, yet many aspects of the fire behaviour of these unique woody fuelbeds remain poorly understood. To examine the effects of fuelbed aging on fire behaviour, we conducted laboratory burns with masticated Arctostaphylos spp. and Ceanothus spp. woody debris that ranged from 2 to 16 years since treatment. Masticated fuels that were 10 years or older burned with 18 to 29% shorter flame heights and 19% lower fireline intensities compared with the younger fuelbeds across three different fuel loads (25, 50 and 75 Mg ha–1). Older fuelbeds smouldered for almost 50% longer than the younger masticated fuelbeds. Fuel consumption was 96% in the two higher fuel load categories regardless of fuelbed age, whereas consumption was 77% in the lighter fuel load. Fire intensity in masticated fuels may decrease over time owing to particle degradation, but in dry environments where decomposition is slow, combustion of the remaining fuels may still pose risks for tree mortality and smoke production associated with protracted smouldering.

A patch mosaic burning system for conservation areas in southern African savannas

2001 ◽  
Vol 10 (2) ◽  
pp. 169 ◽  
Author(s):  
B.H. Brockett ◽  
H.C. Biggs ◽  
B.W. van Wilgen
Keyword(s):  
Prescribed Burning ◽  
Fire Regime ◽  
Weather Conditions ◽  
Dry Season ◽  
Fuel Load ◽  
Fire Season ◽  
Fire Intensity ◽  
Target Area ◽  
Conservation Areas ◽  
Percentage Area

Fire-prone savanna ecosystems in southern African conservation areas are managed by prescribed burning in order to conserve biodiversity. A prescribed burning system designed to maximise the benefits of a diverse fire regime in savanna conservation areas is described. The area burnt per year is a function of the grass fuel load, and the number of fires per year is a function of the percentage area burnt. Fires are point-ignited, under a range of fuel and weather conditions, and allowed to burn out by themselves. The seasonal distribution of planned fires over a year is dependent on the number of fires. Early dry season fires (May–June) tend to be small because fuels have not yet fully cured, while late season fires (August–November) are larger. More fires are ignited in the early dry season, with fewer in the late dry season. The seasonality, area burnt, and fire intensity are spatially and temporally varied across a landscape. This should result in the creation of mosaics, which should vary in extent and existence in time. Envelopes for the accumulated percentage to be burnt per month, over the specified fire season, together with upper and lower buffers to the target area are proposed. The system was formalised after 8 years of development and testing in Pilanesberg National Park, South Africa. The spatial heterogeneity of fire patterns increased over the latter years of implementation. This fire management system is recommended for savanna conservation areas of >20 000 ha in size.

The effect of mastication on surface fire behaviour, fuels consumption and tree mortality in pine flatwoods of Florida, USA

2015 ◽  
Vol 24 (4) ◽  
pp. 573 ◽  
Author(s):  
Jesse K. Kreye ◽  
Leda N. Kobziar
Keyword(s):  
Tree Mortality ◽  
Prescribed Burning ◽  
Fire Hazard ◽  
Fire Effects ◽  
Flame Height ◽  
Soil Conditions ◽  
Fire Behaviour ◽  
Pine Flatwoods ◽  
Southern Us ◽  
Limited Effectiveness

Mastication of understorey shrubs and small trees to reduce fire hazard has become a widespread forest management practice, but few empirical studies have quantified the effects of this mechanical treatment on actual fire behaviour and fire effects at the stand scale. We conducted experimental burns in masticated pine flatwoods with palmetto/gallberry understories, a common ecosystem of the Southern US Coastal Plain. Fire behaviour (flame height, rate of spread) and fire effects were compared between treated and untreated sites burned in the typical winter prescribed burning season. Mastication effectively reduced flame heights by 66%, but recovering shrubs (cover, height) influenced fire behaviour within six months following treatment, suggesting time-limited effectiveness. Trees had less crown scorch and bole char in masticated sites, but tree mortality was minimal on both treated and untreated sites. Consumption of masticated fuel was substantial across both treatments, but little duff was consumed under the moist soil conditions. When burning is conducted soon after treatment, mastication may effectively reduce fire behaviour in pine flatwoods sites, but the duration of treatment efficacy remains unclear.

Fuel accumulation and forest structure change following hazardous fuel reduction treatments throughout California

2015 ◽  
Vol 24 (3) ◽  
pp. 361 ◽  
Author(s):  
Nicole M. Vaillant ◽  
Erin K. Noonan-Wright ◽  
Alicia L. Reiner ◽  
Carol M. Ewell ◽  
Benjamin M. Rau ◽  
...  
Keyword(s):  
Bulk Density ◽  
Prescribed Fire ◽  
Forest Structure ◽  
Fire Regimes ◽  
Post Treatment ◽  
Fuel Load ◽  
Fire Behaviour ◽  
Fuel Treatments ◽  
Minimal Impact ◽  
Canopy Bulk Density

Altered fuel conditions coupled with changing climate have disrupted fire regimes of forests historically characterised by high-frequency and low-to-moderate-severity fire. Managers use fuel treatments to abate undesirable fire behaviour and effects. Short-term effectiveness of fuel treatments to alter fire behaviour and effects is well documented; however, long-term effectiveness is not well known. We evaluated surface fuel load, vegetation cover and forest structure before and after mechanical and fire-only treatments over 8 years across 11 National Forests in California. Eight years post treatment, total surface fuel load returned to 67 to 79% and 55 to 103% of pretreatment levels following fire-only and mechanical treatments respectively. Herbaceous or shrub cover exceeded pretreatment levels two-thirds of the time 8 years after treatment. Fire-only treatments warranted re-entry at 8 years post treatment owing to the accumulation of live and dead fuels and minimal impact on canopy bulk density. In general, mechanical treatments were more effective at reducing canopy bulk density and initially increasing canopy base height than prescribed fire. However, elevated surface fuel loads, canopy base height reductions in later years and lack of restoration of fire as an ecological process suggest that including prescribed fire would be beneficial.

scholarly journals Reconstruction of the Spring Hill Wildfire and Exploration of Alternate Management Scenarios Using QUIC-Fire

Fire ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 72
Author(s):  
Michael R. Gallagher ◽  
Zachary Cope ◽  
Daniel Rosales Giron ◽  
Nicholas S. Skowronski ◽  
Trevor Raynor ◽  
...  
Keyword(s):  
Prescribed Burning ◽  
Fire Management ◽  
Management Strategies ◽  
Fire Behavior ◽  
New Physics ◽  
Fuel Load ◽  
Fire Intensity ◽  
Future Research ◽  
Management Scenarios ◽  
And Training

New physics-based fire behavior models are poised to revolutionize wildland fire planning and training; however, model testing against field conditions remains limited. We tested the ability of QUIC-Fire, a fast-running and computationally inexpensive physics-based fire behavior model to numerically reconstruct a large wildfire that burned in a fire-excluded area within the New York–Philadelphia metropolitan area in 2019. We then used QUIC-Fire as a tool to explore how alternate hypothetical management scenarios, such as prescribed burning, could have affected fire behavior. The results of our reconstruction provide a strong demonstration of how QUIC-Fire can be used to simulate actual wildfire scenarios with the integration of local weather and fuel information, as well as to efficiently explore how fire management can influence fire behavior in specific burn units. Our results illustrate how both reductions of fuel load and specific modification of fuel structure associated with frequent prescribed fire are critical to reducing fire intensity and size. We discuss how simulations such as this can be important in planning and training tools for wildland firefighters, and for avenues of future research and fuel monitoring that can accelerate the incorporation of models like QUIC-Fire into fire management strategies.

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