Corrigendum to: Interdependencies between flame length and fireline intensity in predicting crown fire initiation and crown scorch height

This state-of-knowledge review examines some of the underlying assumptions and limitations associated with the inter-relationships among four widely used descriptors of surface fire behaviour and post-fire impacts in wildland fire science and management, namely Byram's fireline intensity, flame length, stem-bark char height and crown scorch height. More specifically, the following topical areas are critically examined based on a comprehensive review of the pertinent literature: (i) estimating fireline intensity from flame length; (ii) substituting flame length for fireline intensity in Van Wagner's crown fire initiation model; (iii) the validity of linkages between the Rothermel surface fire behaviour and Van Wagner's crown scorch height models; (iv) estimating flame height from post-fire observations of stem-bark char height; and (v) estimating fireline intensity from post-fire observations of crown scorch height. There has been an overwhelming tendency within the wildland fire community to regard Byram's flame length–fireline intensity and Van Wagner's crown scorch height–fireline intensity models as universal in nature. However, research has subsequently shown that such linkages among fire behaviour and post-fire impact characteristics are in fact strongly influenced by fuelbed structure, thereby necessitating consideration of fuel complex specific-type models of such relationships.

Interdependencies between flame length and fireline intensity in predicting crown fire initiation and crown scorch height

This state-of-knowledge review examines some of the underlying assumptions and limitations associated with the inter-relationships among four widely used descriptors of surface fire behaviour and post-fire impacts in wildland fire science and management, namely Byram’s fireline intensity, flame length, stem-bark char height and crown scorch height. More specifically, the following topical areas are critically examined based on a comprehensive review of the pertinent literature: (i) estimating fireline intensity from flame length; (ii) substituting flame length for fireline intensity in Van Wagner’s crown fire initiation model; (iii) the validity of linkages between the Rothermel surface fire behaviour and Van Wagner’s crown scorch height models; (iv) estimating flame height from post-fire observations of stem-bark char height; and (v) estimating fireline intensity from post-fire observations of crown scorch height. There has been an overwhelming tendency within the wildland fire community to regard Byram’s flame length–fireline intensity and Van Wagner’s crown scorch height–fireline intensity models as universal in nature. However, research has subsequently shown that such linkages among fire behaviour and post-fire impact characteristics are in fact strongly influenced by fuelbed structure, thereby necessitating consideration of fuel complex specific-type models of such relationships.

Predicting Postfire Survival in Coulter Pine (Pinus coulteri) and Gray Pine (Pinus sabiniana) after Wildfire in Central California

Factors related to the survival of Coulter pine (Pinus coulteri) and gray pine (P. sabiniana) 3 yr after a September wildfire were evaluated for a site on the central coast of California. Data for 146 Coulter pine and 117 gray pine were analyzed with logistic regression models to estimate postfire survival in relationship to tree and fire-damage variables. Probability of survival for both species decreased with the increasing percentage of crown scorching and increasing height of bole bark char. Crown scorch was the most important variable for predicting survival of these species, but it was augmented by the bole-damage variable. Survival of gray pine was higher than that of Coulter pine for comparable values of both variables. West. J. Appl. For. 17(3):134–138.

Postfire Tree Mortality in Relation to Wildfire Severity in Mixed Oak Forests in the Blue Ridge of Virginia

Tree mortality in relation to fire severity was investigated in eight mixed oak stands in the second growing season following the 1900 ha Big Run Fire in May 1986, in Shenandoah National Park in the Blue Ridge of Virginia. Plots were located in four stands each burned by high- and low-severity fire. Prefire stands were evenaged (55-60 yr), of medium quality (upland oak 50 yr site index 18-20 m ), and dominated by chestnut oak, scarlet oak, northern red oak and pignut hickory. High-severity fire top-killed 67% of stand basal area and 81% of the trees, whereas low-severity fire top-killed 8% of stand basal area and 15% of the trees. Height of stem-bark char accounted for 93 % and 96% of the variation in fire-killed basal area and number of trees, respectively. Logistic regression models relating probability of top-kill of individual trees with tree dbh and height of stem-bark char were developed for chestnut oak, scarlet oak, northern red oak, black oak, pignut hickory, red maple, blackgum, and serviceberry. Regression diagnostics indicated that the models predicted well for all species, with 79 to 95% concordance between predicted probabilities and observed outcomes. The models demonstrate the interaction of species-specific fire resistance, tree size, and fire severity in determining fire induced top-kill. These models can be used to estimate postfire mortality for a variety of purposes, including planning postwildfire timber salvage and regeneration operations, planning prescribed fires, and ecosystem process modeling. North. J. Appl. For. 11(3):90-97.

Modeling Tree Mortality Following Wildfire in Pinus ponderosa Forests in the Central Sierra-Nevada of California

We modeled tree mortality occurring two years following wildfire in Pinus ponderosa forests using data from 1275 trees in 25 stands burned during the 1987 Stanislaus Complex fires. We used logistic regression analysis to develop models relating the probability of wildfire-induced mortality with tree size and fire severity for Pinus ponderosa, Calocedrus decurrens, Quercus chrysolepis, and Q. kelloggii. One set of models predicts mortality probability as a function of DBH and height of stem-bark char, a second set of models uses relative char height (height of stem-bark char as a proportion of tree height) as the predictor. Probability of mortality increased with increasing height of stem-bark char and decreased with increasing tree DBH and height. Analysis of receiver operating characteristic (ROC) curves indicated that both sets of models perform well for all species, with 83 to 96 percent concordance between predicted probabilities and observed outcomes. The models can be used to predict die probability of post-wildfire mortality of four tree species common in Pinus ponderosa forests in the central Sierra Nevada of California.

Effect of Crown Scorch on Survival And Growth of Young Loblolly Pine

Unthinned, pole-size loblolly pine (Pinus taeda L.) plantations in the South Carolina Piedmont were burned at different seasons under minimal wind conditions to evaluate the effects of fire intensity on crown scorch. Needle drop, an indicator of crown scorch, was significantly greater on areas burned with medium- to high-intensity fires than on unburned plots. There was a direct relation between bark char height, beyond a threshold value of 3 feet, and crown scorch. Scorched needles fell within three weeks following fire. Moderate crown scorch had no detrimental effects on survival and growth of trees in the upper crown classes. Complete crown scorch resulted in the death of 20 and 30 percent of trees in the codominant and intermediate crown classes, respectively.