Predicting the Height to Live Crown Base in Plantations of Four Boreal Forest Species

Alpine, RS Mc; Hobbs, M.W.

doi:10.1071/wf9940103

Cited by 22 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…LOGIT4 results are in-between the other three logistic models, yielding reasonable behaviour, although there is the uncertainty about not accounting for the vertical stratification of the fuel complex. Several studies have developed equations to predict canopy base height from commonly available stand characteristics (e.g., Cole and Jensen 1982, McAlpine and Hobbs 1994, Cruz et al 2003a). In the logistic models presented here, the canopy base height is input-variable.…”

Section: Discussionmentioning

confidence: 99%

Assessing the probability of crown fire initiation based on fire danger indices

Cruz¹,

Alexander²,

Wakimoto³

2003

The Forestry Chronicle

View full text Add to dashboard Cite

The initiation of crown fires in conifer stands was modelled through logistic regression analysis by considering as independent variables a basic physical descriptor of the fuel complex structure and selected components of the Canadian Forest Fire Weather Index (FWI) System. The study was based on a fire behaviour research database consisting of 63 experimental fires covering a relatively wide range of burning conditions and fuel type characteristics. Four models were built with decreasing input needs. Significant predictors of crown fire initiation were: canopy base height, wind speed measured at a height of 10 m in the open, and four components of the FWI System (i.e., Fine Fuel Moisture Code, Drought Code, Initial Spread Index and Buildup Index). The models predicted correctly the type of fire (i.e., surface or crown) between 90% and 66% of the time. The C index, a statistical measure, varied from 0.94 to 0.71, revealing good concordance between predicted probabilities and observed events. A comparison between the logistic models and Canadian Forest Fire Behaviour Prediction System models did not show any conclusive differences. The results of a limited evaluation involving two independent experimental fire data sets for distinctly different fuel complexes were encouraging. The logistic models built may have applicability in fire management decision support systems, allowing for the estimation of the probability of crown fire initiation at small and large spatial scales from commonly available fire environment and fire danger rating information. The relationships presented are considered valid for free-burning fires on level terrain in coniferous forests that have reached a pseudo steadystate and are not deemed applicable to dead conifer forests (i.e., insect-killed stands).

show abstract

Section: Discussionmentioning

confidence: 99%

Assessing the probability of crown fire initiation based on fire danger indices

Cruz¹,

Alexander²,

Wakimoto³

2003

The Forestry Chronicle

View full text Add to dashboard Cite

show abstract

“…FSG is defined as the distance from the top of the surface fuelbed to the lower limit of the aerial fuel stratum constituted by the ladder and live crown fuels that can sustain vertical fire propagation. This definition is distinct from previous descriptions of crown or canopy base height (Van Wagner 1977;McAlpine and Hobbs 1994;Cruz et al 2003), in which the vertical fuel gap in the fuel complex is equated to the live canopy base height (CBH ). Surface fuelbed height was defined as done by Brown et al (1982).…”

Section: Energy Transfer To Canopy Fuel Particlesmentioning

confidence: 94%

“…But such quantities can be estimated directly from common stand inventory data (e.g. McAlpine and Hobbs 1994;Cruz et al 2003) or inferred by other means (Keane et al 1998;Riano et al 2003). Stand density and average dbh are required to estimate the radiation opacity coefficient.…”

Section: Model Implementationmentioning

confidence: 99%

Predicting the ignition of crown fuels above a spreading surface fire. Part I: model idealization

Cruz

Butler

Alexander

et al. 2006

Int. J. Wildland Fire

View full text Add to dashboard Cite

A model was developed to predict the ignition of forest crown fuels above a surface fire based on heat transfer theory. The crown fuel ignition model (hereafter referred to as CFIM) is based on first principles, integrating: (i) the characteristics of the energy source as defined by surface fire flame front properties; (ii) buoyant plume dynamics; (iii) heat sink as described by the crown fuel particle characteristics; and (iv) energy transfer (gain and losses) to the crown fuels. Fuel particle temperature increase is determined through an energy balance relating heat absorption to fuel particle temperature. The final model output is the temperature of the crown fuel particles, which upon reaching ignition temperature are assumed to ignite. CFIM predicts the ignition of crown fuels but does not determine the onset of crown fire spread per se. The coupling of the CFIM with models determining the rate of propagation of crown fires allows for the prediction of the potential for sustained crowning. CFIM has the potential to be implemented in fire management decision support systems.

show abstract

“…One of the main problems is the lack of a universally accepted definition for the lower limit of the canopy fuel layer [23]. Several authors [23,45,52,79] consider as CBH the distance from the forest floor to the live crown base. Wilson and Baker [83] used the midpoint between the minimum CBH from the ground and the average live crown height for calculating crown fire initiation risk in multi-layered stands.…”

Section: Cbhmentioning

confidence: 99%

Canopy fuel characteristics and potential crown fire behavior in Aleppo pine (Pinus halepensis Mill.) forests

Mitsopoulos

Dimitrakopoulos

2007

Ann. For. Sci.

View full text Add to dashboard Cite

-Canopy fuel characteristics that influence the initiation and spread of crown fires were measured in representative Aleppo pine (Pinus halepensis Mill.) stands in Greece. Vertical distribution profiles of canopy fuel load, canopy base height and canopy bulk density are presented. Aleppo pine canopy fuels are characterized by low canopy base height (3.0−6.5 m), while available canopy fuel load (0.96−1.80 kg/m 2 ) and canopy bulk density (0.09−0.22 kg/m 3 ) values are similar to other conifers worldwide. Crown fire behavior (probability of crown fire initiation, crown fire type, rate of spread, fireline intensity and flame length) in Aleppo pine stands with various understory fuel types was simulated with the most updated crown fire models. The probability of crown fire initiation was high even under moderate burning conditions, mainly due to the low canopy base height and the heavy surface fuel load. Passive crown fires resulted mostly in uneven aged stands, while even aged stands gave high intensity active crown fires. Assessment of canopy fuel characteristics and potential crown fire behavior can be useful in fuel management and fire suppression planning.canopy fuels / crown fires / fire behavior / Aleppo pine (Pinus halepensis Mill.) / Mediterranean Basin Résumé -Caractéristiques des combustibles de la canopée et comportement du potentiel de feu des couronnes de forêts de Pin d'Alep (Pinus halepensis Mill.). Les caractéristiques des combustibles qui influencent le démarrage et la propagation des feux de couronnes ont été mesurées dans des peuplements représentatifs de Pinus halepensis Mill. en Grèce. Des profils verticaux de la charge en combustible de la canopée, la hauteur de la base de la canopée et la densité volumique de la canopée sont présentés. La charge combustible de la canopée est caractérisée par une faible hauteur de la base de la canopée (3,0−6,5 m), tandis que la charge en combustible disponible (0,96−1,80 kg/m 2 ) et la densité volumique de la canopée (0,09−0,22 kg/m 3 ) sont similaires à celles des autres conifères dans le monde. Le comportement du feu de couronne (probabilité de démarrage du feu dans les couronnes, type de feu de couronne, taux de propagation, intensité de la ligne de feu et longueur des flammes) dans les peuplements de Pinus halepensis avec différents types de combustibles de sous-bois a été simulé avec le maximum de modèles actuels de feux de couronnes. La probabilité de démarrage de feu de couronne était forte même en conditions de faible embrasement, principalement en relation avec la faible hauteur de la base des couronnes et la forte charge en combustible au sol. Des feux passifs de couronnes se produisent principalement dans les peuplements inéquiennes tandis que les peuplements équiennes ont présenté de fortes intensités de feux actifs de couronnes. L'évaluation des caractéristiques des combustibles de la canopée et le comportement du potentiel de feu peuvent être très utiles pour la gestion des combustibles et la planification de la lutte contre les feux. c...

show abstract

Predicting the Height to Live Crown Base in Plantations of Four Boreal Forest Species

Cited by 22 publications

References 0 publications

Assessing the probability of crown fire initiation based on fire danger indices

Assessing the probability of crown fire initiation based on fire danger indices

Predicting the ignition of crown fuels above a spreading surface fire. Part I: model idealization

Canopy fuel characteristics and potential crown fire behavior in Aleppo pine (Pinus halepensis Mill.) forests

Contact Info

Product

Resources

About