Three Types of Horizontal Vortices Observed in Wildland Mass and Crown Fires

1987 ◽  
Vol 26 (12) ◽  
pp. 1624-1637 ◽  
Author(s):  
Donald A. Haines ◽  
Mahlon C. Smith
Keyword(s):  
Crown Fires

Charcoal signatures defined by multivariate analysis of charcoal records from 10 lakes in northwest Wisconsin (USA)

2011 ◽  
Vol 75 (1) ◽  
pp. 125-137 ◽  
Author(s):  
Elizabeth A. Lynch ◽  
Sara C. Hotchkiss ◽  
Randy Calcote
Keyword(s):  
Late Holocene ◽  
Climate Changes ◽  
Regional Climate ◽  
Fire Regimes ◽  
Small Scale ◽  
Regional Patterns ◽  
Crown Fires ◽  
Sand Plain ◽  
In Fire ◽  
Standard Techniques

AbstractWe show how sedimentary charcoal records from multiple sites within a single landscape can be used to compare fire histories and reveal small scale patterns in fire regimes. Our objective is to develop strategies for classifying and comparing late-Holocene charcoal records in Midwestern oak- and pine-dominated sand plain ecosystems where fire regimes include a mix of surface and crown fires. Using standard techniques for the analysis of charcoal from lake sediments, we compiled 1000- to 4000-yr-long records of charcoal accumulation and charcoal peak frequencies from 10 small lakes across a sand plain in northwestern Wisconsin. We used cluster analysis to identify six types of charcoal signatures that differ in their charcoal influx rates, amount of grass charcoal, and frequency and magnitude of charcoal peaks. The charcoal records demonstrate that while fire histories vary among sites, there are regional patterns in the occurrence of charcoal signature types that are consistent with expected differences in fire regimes based on regional climate and vegetation reconstructions. The fire histories also show periods of regional change in charcoal signatures occurring during times of regional climate changes at ~700, 1000, and 3500 cal yr BP.

scholarly journals Frequency of Dynamic Fire Behaviours in Australian Forest Environments

Fire ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Alexander I. Filkov ◽  
Thomas J. Duff ◽  
Trent D. Penman
Keyword(s):  
Empirical Analysis ◽  
Land Management ◽  
Quantitative Data ◽  
Economic Losses ◽  
High Frequencies ◽  
Crown Fires ◽  
Direct Data ◽  
Social Environmental

Wildfires can result in significant social, environmental and economic losses. Fires in which dynamic fire behaviours (DFBs) occur contribute disproportionately to damage statistics. Little quantitative data on the frequency at which DFBs occur exists. To address this problem, we conducted a structured survey using staff from fire and land management agencies in Australia regarding their experiences with DFBs. Staff were asked which, if any, DFBs were observed within fires greater than 1000 ha from the period 2006–2016 that they had experience with. They were also asked about the nature of evidence to support these observations. One hundred thirteen fires were identified. Eighty of them had between one and seven DFBs with 73% (58 fires) having multiple types of DFBs. Most DFBs could commonly be identified through direct data, suggesting an empirical analysis of these phenomena should be possible. Spotting, crown fires and pyro-convective events were the most common DFBs (66%); when combined with eruptive fires and conflagrations, these DFBs comprise 89% of all cases with DFBs. Further research should be focused on these DFBs due to their high frequencies and the fact that quantitative data are likely to be available.

Modelling the rate of fire spread and uncertainty associated with the onset and propagation of crown fires in conifer forest stands

2017 ◽  
Vol 26 (5) ◽  
pp. 413 ◽  
Author(s):  
Miguel G. Cruz ◽  
Martin E. Alexander
Keyword(s):  
Monte Carlo ◽  
Average Rate ◽  
Fire Spread ◽  
Prediction Errors ◽  
Crown Fire ◽  
Conifer Forest ◽  
Fire Behaviour ◽  
Crown Fires ◽  
Deterministic Modelling ◽  
Eastern Australia

Crown fires are complex, unstable phenomena dependent on feedback mechanisms between the combustion products of distinct fuel layers. We describe non-linear fire behaviour associated with crowning and the uncertainty they cause in fire behaviour predictions by running a semiphysical modelling system within a simple Monte Carlo simulation framework. The method was able to capture the dynamics of passive and active crown fire spread regimes, providing estimates of average rate of spread and the extent of crown fire activity. System outputs were evaluated against data collected from a wildfire that occurred in a radiata pine plantation in south-eastern Australia. The Monte Carlo method reduced prediction errors relative to the more commonly used deterministic modelling approach, and allowed a more complete description of the level of crown fire behaviour to expect. The method also provides uncertainty measures and probabilistic outputs, extending the range of questions that can be answered by fire behaviour models.

scholarly journals Wildfire during deposition of the “Illinger Flözzone” (Heusweiler-Formation, “Stephanian B”, Kasimovian–Ghzelian) in the Saar-Nahe Basin (SW-Germany)

2020 ◽  
Author(s):  
Dieter Uhl ◽  
André Jasper
Keyword(s):  
Atmospheric Oxygen ◽  
Anatomical Features ◽  
Seasonally Dry ◽  
Surface Fires ◽  
Dead Trees ◽  
Crown Fires ◽  
Oxygen Conditions ◽  
Wet Tropics

Abstract Wildfires occurred more or less regularly in many Pennsylvanian ecosystems, not only in seasonally dry regions but also in the ever wet tropics. One of the reasons for this was probably the relatively high atmospheric oxygen conditions prevailing during this period. The present study reports evidence for the occurrence of wildfires during deposition of the Upper Pennsylvanian Heusweiler Formation (“Stephanian B”, Kasimovian–Gzhelian) in the intramontane Saar-Nahe (or Saar-Lorraine) Basin in SW-Germany. Based on anatomical features of the charcoal, as well as the co-occurring adpression flora, it seems possible that some of the fires occurred in an ecosystem inhabited by Cordaites. Some of the charcoal fragments exhibit traces of pre-charring decay by fungi, indicating either the consumption of litter by ground or surface fires, or of still standing (partly) dead trees by crown fires.

Prescribed fire as a tool to regenerate live and dead serotinous jack pine (Pinus banksiana) stands

2017 ◽  
Vol 26 (6) ◽  
pp. 478 ◽  
Author(s):  
Maria Sharpe ◽  
Hyejin Hwang ◽  
David Schroeder ◽  
Soung Ryoul Ryu ◽  
Victor J. Lieffers
Keyword(s):  
Prescribed Fire ◽  
Natural Regeneration ◽  
Pinus Banksiana ◽  
Mountain Pine Beetle ◽  
Jack Pine ◽  
Crown Fire ◽  
Seedling Regeneration ◽  
Dead Trees ◽  
Crown Fires ◽  
Pine Beetle

This study documents cone opening and natural regeneration of jack pine (Pinus banksiana Lamb.) after burning live and dead stands similar to those killed by the mountain pine beetle (Dendroctonus ponderosae). Trees were killed by girdling in May and were burned in late July, 26 months later. Pairs of live and dead plots were simultaneously burned using three types of fire: surface, intermittent crown and continuous crown fires. Each type of fire was replicated three times; the nine pairs of burns were completed in a 4-day period. After fire, more cones were opened on dead trees than live trees. On dead trees, there was cone opening even when fire charred only the lower part of the bole. Three years after burning, dead stands with continuous crown fires had some of the densest regeneration and the highest rates of stocking. Across all burns in this study, seedling regeneration was best in shallow residual duff and in the more intensely burned plots. Without burning, there was virtually no regeneration 5 years after mortality. The results also show that burning, especially under continuous crown fire, could be used to promote regeneration in dead stands.

Predicted and Observed Rates of Spread of Crown Fires in Immature Jack Pine

1986 ◽  
Vol 48 (1-2) ◽  
pp. 65-76 ◽  
Author(s):  
FRANK A. ALBINI ◽  
BRIAN J. STOCKS
Keyword(s):  
Jack Pine ◽  
Crown Fires

FIRE SEVERITY AND ECOSYTEM RESPONSES FOLLOWING CROWN FIRES IN CALIFORNIA SHRUBLANDS

2008 ◽  
Vol 18 (6) ◽  
pp. 1530-1546 ◽  
Author(s):  
Jon E. Keeley ◽  
Teresa Brennan ◽  
Anne H. Pfaff
Keyword(s):  
Fire Severity ◽  
Crown Fires

scholarly journals Repeated Stand-Replacing Crown Fires Affect Seed Morphology and Germination in Aleppo pine

2017 ◽  
Vol 8 ◽  
Author(s):  
Antonio Saracino ◽  
Alessandro Bellino ◽  
Emilia Allevato ◽  
Antonio Mingo ◽  
Stefano Conti ◽  
...  
Keyword(s):  
Seed Morphology ◽  
Aleppo Pine ◽  
Crown Fires

Canopy bulk density and canopy base height equations for assessing crown fire hazard in Pinus radiata plantations

2011 ◽  
Vol 41 (4) ◽  
pp. 839-850 ◽  
Author(s):  
Ana Daría Ruiz-González ◽  
Juan Gabriel Álvarez-González
Keyword(s):  
Bulk Density ◽  
Pinus Radiata ◽  
Fire Hazard ◽  
Direct Action ◽  
Quantitative Information ◽  
Wildlife Habitat ◽  
Vertical Profiles ◽  
Crown Fire ◽  
Crown Fires ◽  
Canopy Bulk Density

Crown fires combine high rates of spread, flame lengths, and intensities, making it virtually impossible to control them by direct action and having significant impact on soils, vegetation, and wildlife habitat. For these reasons, fire managers have great interest in preventive silviculture of forested landscapes to avoid the initiation and propagation of crown fires. The minimum conditions necessary to initiate and propagate crown fires are assumed to be strongly influenced by the stand structural variables canopy bulk density (CBD) and canopy base height (CBH). However, there is a lack of quantitative information on these variables and how to estimate them. To characterize the aerial fuel layers of Pinus radiata D. Don, the vertical profiles of canopy fuel in 180 sample plots of pure and even-aged P. radiata plantations were analysed. Effective CBD and CBH were obtained from the vertical profiles, and equations relating these variables to common stand variables were fitted simultaneously. Inclusion of the fitted equations in existing dynamic growth models, together with the use of current fire behaviour and hazard prediction tools, will provide a decision support system for assessing the crown fire potential of different silvicultural alternatives for this species.

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