Lodgepole pine and white spruce crown fuel weights predicted from height and crown width

Johnson, Allen F.; Woodard, Paul M.; Titus, Stephen J.

doi:10.1139/x89-083

Cited by 7 publications

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“…However, crown biomass equations are not available for all tree species, size classes, and stand conditions, so this method is impractical for many forested ecosystems. Johnson et al (1989) developed crown fuel component biomass equations for lodgepole pine and white spruce using tree height and crown width but did not predict the vertical distribution of canopy fuels. The allometric approach for predicting CBD has not been previously validated and is restricted to those forest types with appropriate biomass equations.…”

Section: Current Methodsmentioning

confidence: 99%

Estimating forest canopy bulk density using six indirect methods

Keane¹,

Reinhardt²,

Scott³

et al. 2005

Can. J. For. Res.

108

109

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Canopy bulk density (CBD) is an important crown characteristic needed to predict crown fire spread, yet it is difficult to measure in the field. Presented here is a comprehensive research effort to evaluate six indirect sampling techniques for estimating CBD. As reference data, detailed crown fuel biomass measurements were taken on each tree within fixed-area plots located in five important conifers types in the western United States, using destructive sampling following a series of four sampling stages to measure the vertical and horizontal distribution of canopy biomass. The six ground-based indirect measurement techniques used these instruments: LI-COR LAI-2000, AccuPAR ceptometer, CID digital plant canopy imager, hemispherical photography, spherical densiometer, and point sampling. These techniques were compared with four aggregations of crown biomass to compute CBD: foliage only, foliage and small branchwood, foliage and all branchwood (no stems), and all canopy biomass components. Most techniques had the best performance when all canopy biomass components except stems were used. Performance dropped only slightly when the foliage and small branchwood canopy biomass aggregation (best approximates fuels available for crown fires) was employed. The LAI-2000, hemispherical photography, and CID plant canopy imager performed best. Regression equations that predict CBD from gap fraction are presented for all six techniques.Résumé : La densité apparente de la canopée (DAC) est une caractéristique importante de la cime qui est nécessaire pour prédire la propagation d'un feu de cime mais qui est cependant très difficile à mesurer sur le terrain. Les auteurs présentent ici un travail de recherche exhaustif dont le but était d'évaluer six techniques indirectes d'échantillonnage pour estimer la DAC. Les données de référence proviennent de mesures détaillées de la biomasse des combustibles dans la cime prises sur chaque arbre dans des placettes à superficie fixe situées dans cinq types importants de forêt résineuse de l'ouest des États-Unis en utilisant une approche destructrice après avoir procédé à une série d'échantillonnages en quatre étapes pour mesurer la distribution verticale et horizontale de la biomasse dans la canopée. Les six techniques indirectes de mesure sur le terrain comprenaient les instruments suivants : le LAI-2000 de LI-COR, le ceptomètre d'AccuPAR, l'imageur digital du couvert végétal CID, la photographie hémisphérique, le densiomètre sphérique et l'échantillonnage par point. Ces techniques ont été comparées à quatre regroupements de la biomasse de la cime pour calculer la DAC : feuillage seulement, feuillage et petites branches, feuillage et toutes les branches (sans la tige) et toutes les composantes de la biomasse de la cime. La plupart des techniques offraient la meilleure performance lorsque toutes les composantes de la biomasse de la canopée, à l'exception de la tige, étaient utilisées. La performance diminuait juste un peu avec l'utilisation du regroupement de la biomasse de la cano...

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Section: Current Methodsmentioning

confidence: 99%

Estimating forest canopy bulk density using six indirect methods

Keane¹,

Reinhardt²,

Scott³

et al. 2005

Can. J. For. Res.

108

109

View full text Add to dashboard Cite

show abstract

“…Nevertheless, current research efforts state that in certain fuel complexes, other fuel categories, such as the fine twigs, may significantly contribute to the heat released from the flaming zone of a crown fire [19,70,76]. Although numerous studies correlate crown or foliage biomass with tree dendrometric characteristics [13,37,46,51,53,55,56], only few studies measure crown fuel load by diameter size class at tree level [15,39,40,73] and at stand level [9,23], as it is required in crown fire behavior modeling.…”

Section: Cflmentioning

confidence: 99%

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

Mitsopoulos

Dimitrakopoulos

2007

Ann. For. Sci.

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-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...

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“…Although numerous studies correlate crown or foliage biomass with tree dendrometric characteristics (Kittredge 1944;Moeur 1981;Grigal and Kernik 1984;Baldwin et al 1997;Monserud and Marshall 1999), few studies measure crown fuel load by diameter size classes (Brown 1978;Stocks 1980;Johnson et al 1989Johnson et al , 1990 as it is required in fire behaviour modelling.…”

Section: Introductionmentioning

confidence: 99%

Allometric equations for crown fuel biomass of Aleppo pine (Pinus halepensis Mill.) in Greece

Mitsopoulos

Dimitrakopoulos

2007

Int. J. Wildland Fire

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Allometric equations for the estimation of crown fuel weight of Aleppo pine (Pinus halepensis Mill.) trees in the Mediterranean Basin were developed. Forty trees were destructively sampled and their crown fuels were weighed separately for each fuel category. Crown fuel components, both living and dead, were separated into size classes and regression equations that estimate crown fuel load by diameter class were derived. The allometric equation y = ax b with diameter at breast height as the single predictor was chosen, because the addition of other parameters did not decrease the residual sum of squares significantly. The adjusted coefficient of determination (R 2 adj ) values were high (R 2 adj = 0.82-0.88) in all cases. Diameter at breast height was the most significant determinant of crown fuel biomass. The aerial fuels that are consumed during crown fires (i.e. needles and twigs with diameter less than 0.63 cm) comprised 29.3% of the total crown weight. Live fuels constituted ∼96.3% of total crown biomass, distributed as follows: needles 16.7% (average load 12.07 kg), branches with 0.0-0.63-cm diameter 12.6% (average load 9.18 kg), 0.64-2.5-cm diameter 37.3% (27.99 kg), 2.51-7.5-cm diameter 25.4% (18.59 kg), and >7.5-cm diameter 3.7% (2.65 kg). The equations provide quantitative fuel biomass attributes for use in crown fire behaviour models, fire management and carbon assessment in Aleppo pine stands.Additional keyword: crown fires.

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Lodgepole pine and white spruce crown fuel weights predicted from height and crown width

Cited by 7 publications

References 0 publications

Estimating forest canopy bulk density using six indirect methods

Estimating forest canopy bulk density using six indirect methods

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

Allometric equations for crown fuel biomass of Aleppo pine (Pinus halepensis Mill.) in Greece

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