The effect of woody fuel characteristics on fuel ignition and consumption: a case study from a eucalypt forest in south-west Western Australia

2018 ◽  
Vol 27 (5) ◽  
pp. 363 ◽  
Author(s):  
J. J. Hollis ◽  
W. L. McCaw ◽  
M. G. Cruz
Keyword(s):  
Fuel Consumption ◽  
Fire History ◽  
Management Practices ◽  
Woody Debris ◽  
Fuel Load ◽  
Fire Behaviour ◽  
Ecological Processes ◽  
Eucalypt Forest ◽  
Eucalypt Forests ◽  
Fuel Particles

Coarse woody debris (>0.6 cm in diameter) is an important component of the fuel complex in Australian eucalypt forests, influencing both fire behaviour, smoke production and post-fire ecological processes. We investigated how physical characteristics of woody fuel affected ignition and consumption during an experimental fire where the fuel complex characteristics, fire weather and fire behaviour varied within a narrow range. Decay status, bark condition, arrangement, suspension and extent of charring were classified for 2866 coarse woody fuel particles. We used generalised linear model (GLM) analysis to explain ignition success and the extent of consumption of individual particles, with a focus on larger diameter fuels (>7.5 cm in diameter), which comprised 83% of the woody fuel load and 94% of the woody fuel consumed during the flaming and smouldering stages of combustion. Ignition success was best explained by a model that included fuel arrangement (a surrogate of fuel proximity), suspension and decay status. The extent of fuel consumption was greater for pieces in advanced stages of decay, but suspension (inversely related) and arrangement (directly related) also affected the outcome. Forest management practices, previous fire history and other natural disturbances are likely to influence the distribution of pre-fire diameters and suspension classes that characterise large woody fuels at a site, and will therefore influence woody fuel consumption. This has practical implications for quantifying heat release and atmospheric emissions from fires burning in forests with different management histories.

Corrigendum to: The effect of woody fuel characteristics on fuel ignition and consumption: a case study from a eucalypt forest in south-west Western Australia

2019 ◽  
Vol 28 (8) ◽  
pp. 640
Author(s):  
J. J. Hollis ◽  
W. L. McCaw ◽  
M. G. Cruz
Keyword(s):  
Fuel Consumption ◽  
Fire History ◽  
Management Practices ◽  
Woody Debris ◽  
Fuel Load ◽  
Fire Behaviour ◽  
Ecological Processes ◽  
Eucalypt Forest ◽  
Eucalypt Forests ◽  
Fuel Particles

Coarse woody debris (>0.6cm in diameter) is an important component of the fuel complex in Australian eucalypt forests, influencing both fire behaviour, smoke production and post-fire ecological processes. We investigated how physical characteristics of woody fuel affected ignition and consumption during an experimental fire where the fuel complex characteristics, fire weather and fire behaviour varied within a narrow range. Decay status, bark condition, arrangement, suspension and extent of charring were classified for 2866 coarse woody fuel particles. We used generalised linear model (GLM) analysis to explain ignition success and the extent of consumption of individual particles, with a focus on larger diameter fuels (>7.5cm in diameter), which comprised 83% of the woody fuel load and 94% of the woody fuel consumed during the flaming and smouldering stages of combustion. Ignition success was best explained by a model that included fuel arrangement (a surrogate of fuel proximity), suspension and decay status. The extent of fuel consumption was greater for pieces in advanced stages of decay, but suspension (inversely related) and arrangement (directly related) also affected the outcome. Forest management practices, previous fire history and other natural disturbances are likely to influence the distribution of pre-fire diameters and suspension classes that characterise large woody fuels at a site, and will therefore influence woody fuel consumption. This has practical implications for quantifying heat release and atmospheric emissions from fires burning in forests with different management histories.

Project Vesta: Fire in Dry Eucalypt Forest

2008 ◽  
Author(s):  
JS Gould ◽  
WL McCaw ◽  
NP Cheney ◽  
PF Ellis ◽  
IK Knight ◽  
...  
Keyword(s):  
Wind Speed ◽  
Fire Spread ◽  
Fire Behaviour ◽  
Understorey Vegetation ◽  
Eucalypt Forest ◽  
Age Related ◽  
Vegetation Structures ◽  
Eucalypt Forests ◽  
The Relationship ◽  
New Algorithms

Project Vesta was a comprehensive research project to investigate the behaviour and spread of high-intensity bushfires in dry eucalypt forests with different fuel ages and understorey vegetation structures. The project was designed to quantify age-related changes in fuel attributes and fire behaviour in dry eucalypt forests typical of southern Australia. The four main scientific aims of Project Vesta were: To quantify the changes in the behaviour of fire in dry eucalypt forest as fuel develops with age (i.e. time since fire); To characterise wind speed profiles in forest with different overstorey and understorey vegetation structure in relation to fire behaviour; To develop new algorithms describing the relationship between fire spread and wind speed, and fire spread and fuel characteristics including load, structure and height; and to develop a National Fire Behaviour Prediction System for dry eucalypt forests. These aims have been addressed through a program of experimental burning and associated studies at two sites in the south-west of Western Australia.

Flame residence times and rates of weight loss of eucalypt forest fuel particles

2001 ◽  
Vol 10 (2) ◽  
pp. 137 ◽  
Author(s):  
N. D. Burrows
Keyword(s):  
Weight Loss ◽  
Forest Fire ◽  
Size Composition ◽  
Scientific Basis ◽  
Residence Times ◽  
Fire Behaviour ◽  
Eucalypt Forest ◽  
Round Wood ◽  
Fine Fuels ◽  
Fuel Particles

Shape, size, composition and arrangement of fuel particles within a fuel array significantly affect the way in which wildland fires behave. Australian eucalypt forest fire behaviour models characterise fine fuels according to the quantity burnt in the flaming zone, and the upper size limit for fine fuel particles is somewhat arbitrarily set at 6 mm for the McArthur Forest Fire Danger Meter and 10 mm for the Forest Fire Behaviour Tables for Western Australia. Flame residence time and rate of weight loss during combustion of dry eucalypt leaves and different dimensions of round wood were measured to provide a scientific basis for standardising litter fuel sampling in dry eucalypt forests. Eucalypt leaves burnt at a rate equivalent to a piece of 4 mm diameter round wood, with smaller diameter round wood being the most flammable component of the fuel array. Based on flame residence times of individual fuel particles measured in the laboratory, and eucalypt surface fuel arrays observed in the field, fine litter fuel sampling should be standardised to leaves and round wood less than 6 mm in diameter. This study also enables the determination of the contribution of larger fuel particles to flaming zone combustion and intensity.

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.

Field Guide: Fire in Dry Eucalypt Forest

2008 ◽  
Author(s):  
JS Gould ◽  
WL McCaw ◽  
NP Cheney ◽  
PF Ellis ◽  
S Matthews
Keyword(s):  
Fire Spread ◽  
Flame Height ◽  
Fire Behaviour ◽  
Effective Response ◽  
Understorey Vegetation ◽  
Near Surface ◽  
Field Guide ◽  
Eucalypt Forest ◽  
Rate Of Spread ◽  
Eucalypt Forests

An effective response to bushfires relies on accurate predictions of fire behaviour, particularly the rate of spread, intensity and ‘spotting’. This field guide has been developed to provide a systematic method for assessing fuel hazard and predicting potential fire behaviour in dry eucalypt forest. It will assist in making vital decisions that ensure the protection of fire crews and the community. This guide integrates Project Vesta research findings with the Victorian Overall Fuel Hazard Guide and is applicable to dry eucalypt forests throughout southern Australia. Fuel assessment is based on the hazard scoring system employed during Project Vesta which investigated the effects of fuel age and understorey vegetation structure on fire behaviour in these forests. Information provided in this guide can be used to: Define and identify different fuel layers and components of fuel structure and hazard; Determine the hazard score of surface and near-surface fuel layers and the height of the near-surface fuel for fire spread prediction; Determine elevated fuel height for flame height prediction; and determine surface fuel hazard score and bark hazard score for spotting distance prediction. The Field Guide provides tables to predict the potential rate of spread of a bushfire burning in dry eucalypt forest under summer conditions, and can also be used to predict flame height and maximum spotting distance. The guide also allows users to determine the moisture content of fine dead fuels throughout the day, and to account for the effect of slope on the rate of spread of a fire.

scholarly journals Pyrolysis Characteristics of Undervalued Wood Varieties in the Portuguese Charcoal Sector

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2537
Author(s):  
Felix Charvet ◽  
Felipe Silva ◽  
Luís Ruivo ◽  
Luís Tarelho ◽  
Arlindo Matos ◽  
...  
Keyword(s):  
Large Scale ◽  
Fixed Bed ◽  
Management Control ◽  
Fixed Bed Reactor ◽  
Fuel Load ◽  
Charcoal Production ◽  
Pyrolysis Characteristics ◽  
Major Market ◽  
Burnt Wood ◽  
Fuel Particles

Charcoal production in Portugal is mostly based on the valorization of woody residues from cork oak and holm oak, the latter being considered a reference feedstock in the market. Nevertheless, since wildfire prevention became a priority in Portugal, after the recent dramatic wildfires, urgent actions are being conducted to reduce the fuel load in the forests, which is increasing the amount of biomass that is available for valorization. Additionally, biomass residues from agriculture, forest management, control of invasive species, partially burnt wood from post-fire recovery actions, and waste wood from storm devastated forests need also to be considered within the national biomass valorization policies. This has motivated the present work on whether the carbonization process can be used to valorize alternative woody biomasses not currently used on a large scale. For this purpose, slow pyrolysis experiments were carried out with ten types of wood, using a fixed bed reactor allowing the controlled heating of large fuel particles at 0.1 to 5 °C/min and final temperatures within 300–450 °C. Apart from an evaluation of the mass balance of the process, emphasis was given to the properties of the resulting charcoals considering its major market in Portugal—barbecue charcoal for both recreational and professional purposes.

Fire Management of Rangelands in the Kimberley Low-Rainfall Zone: a Review.

1999 ◽  
Vol 21 (1) ◽  
pp. 39 ◽  
Author(s):  
AB Craig
Keyword(s):  
Fire History ◽  
Fire Management ◽  
Fire Regime ◽  
Fire Regimes ◽  
Environmental Research ◽  
Fire Behaviour ◽  
General Management ◽  
Noaa Avhrr ◽  
Local Experience ◽  
Definition Of

This paper examines a range of environmental, research and practical issues affecting fire management of pastoral lands in the southern part of the Kimberley region in Western Australia. Although spinifex grasslands dominate most leases, smaller areas of more productive pastures are crucially important to many enterprises. There is a lack of local documentation of burning practices during traditional Aboriginal occupation; general features of the fire regime at that time can be suggested on the basis of information from other inland areas. Definition of current tire regimes is improving through interpretation of NOAA-AVHRR satellite imagery. Irregular extensive wildfires appear to dominate, although this should be confirmed by further accumulation, validation and analysis of fire history data. While these fires cause ma,jor difficulties. controlled burn~ng is a necessary part of station management. Although general management guidelines have been published. local research into tire-grazing effects has been very limited. For spinifex pastures, reconimendations are generally consistent with those applying elsewhere in northern Australia. They favour periodic burning of mature spinifex late in the year, before or shortly after the arrival of the first rains, with deferment of grazing. At that time. days of high fire danger may still be expected and prediction of fire behaviour is critical to burning decisions. Early dry-season burning is also required for creating protective tire breaks and to prepare for burning later in the year. Further development of tools for predicting fire behaviour, suited to the discontinuous fuels characteristic of the area, would be warranted. A range of questions concerning the timing and spatial pattern of burning, control of post-fire grazing, and the economics of fire management, should be addressed as resources permit. This can be done through a combination of opportunistic studies, modelling and documentation of local experience. The development of an expert system should be considered to assist in planning and conducting burning activities. Key words: Kimberley, fire regimes, fire management, pastoralism, spinifex

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.

Log landings are methane emission hotspots in managed forests

2021 ◽  
Author(s):  
Juliana Vantellingen ◽  
Sean C. Thomas
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Management Practices ◽  
Emission Rate ◽  
Woody Debris ◽  
Organic Matter Content ◽  
Growing Season ◽  
Matter Content ◽  
Emission Rates ◽  
Managed Forests

Log landings are areas within managed forests used to process and store felled trees prior to transport. Through their construction and use soil is removed or redistributed, compacted, and organic matter contents may be increased by incorporation of wood fragments. The effects of these changes to soil properties on methane (CH<sub>4</sub>) flux is unclear and unstudied. We quantified CH<sub>4</sub> flux rates from year-old landings in Ontario, Canada, and examined spatial variability and relationships to soil properties within these sites. Landings emitted CH<sub>4</sub> throughout the growing season; the average CH<sub>4</sub> emission rate from log landings was 69.2 ± 12.8 nmol m<sup>-2</sup> s<sup>-1</sup> (26.2 ± 4.8 g CH<sub>4</sub> C m<sup>-2</sup> y<sup>-1</sup>), a rate comparable to CH<sub>4</sub>-emitting wetlands. Emission rates were correlated to soil pH, organic matter content and quantities of buried woody debris. These properties led to strong CH<sub>4</sub> emissions, or “hotspots”, in certain areas of landings, particularly where processing of logs occurred and incorporated woody debris into the soil. At the forest level, emissions from landings were estimated to offset ~12% of CH<sub>4</sub> consumption from soils within the harvest area, although making up only ~0.5% of the harvest area. Management practices to avoid or remediate these emissions should be developed as a priority measure in “climate-smart” forestry.

Visual assessments of fuel loads are poorly related to destructively sampled fuel loads in eucalypt forests

2016 ◽  
Vol 25 (11) ◽  
pp. 1193 ◽  
Author(s):  
Liubov Volkova ◽  
Andrew L. Sullivan ◽  
Stephen H. Roxburgh ◽  
Christopher J. Weston
Keyword(s):  
Visual Assessment ◽  
Fuel Load ◽  
Poor Correlation ◽  
Random Allocation ◽  
Near Surface ◽  
Forest Fuels ◽  
Fuel Loads ◽  
Rate Of Spread ◽  
Eucalypt Forests ◽  
Visual Assessments

Fire managers around the world commonly use visual assessment of forest fuels to aid prediction of fire behaviour and plan for hazard reduction burning. In Australia, fuel hazard assessment guides also allow conversion of visual assessments to indicative fuel loads, which is essential for some rate of spread models and calculation of fireline intensity or emissions. The strength of correlation between fuel hazard and destructively sampled (directly measured) fuel load was tested using a comprehensive dataset of >500 points from across a range of eucalypt forests in Australia. Overall, there was poor correlation between the assigned fuel hazard rating and measured biomass for surface, near-surface and elevated fuel components, with a clear tendency for these systems to under-predict fuel load at low hazard ratings, and over-predict it at high hazard ratings. Visual assessment of surface fuels was not statistically different from a random allocation of hazard level. The considerable overlap in fuel load between hazard ratings at higher ranges suggests the need to reduce the number of hazard classes to provide clearer differentiation of fuel hazard. To accurately assess forest fuel condition, improvements in fuel hazard descriptions and calibration of visual assessment with destructively measured fuels is essential.

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