________________________________________This report describes a new set of standard fire behavior fuel models for use with Rothermel's surface fire spread model and the relationship of the new set to the original set of 13 fire behavior fuel models. To assist with transition to using the new fuel models, a fuel model selection guide, fuel model crosswalk, and set of fuel model photos are provided.Keywords: fire behavior prediction, fire modeling, surface fuel, dynamic fuel model The Authors _____________________________________ Joe H. Scott has been a Forester with Systems for Environmental Management, a nonprofit research group based in Missoula, MT, since 1996. He is the lead developer of NEXUS, a system for assessing crown fire potential; lead developer of FireWords, an annotated, electronic glossary of fire science terminology; and codeveloper of FuelCalc, a system for computing, summarizing, and formatting ground, surface, and crown fuel characteristics from standard inventory methods. Scott has participated in several investigations of surface and canopy fuel characteristics. He has a B.S. degree in forestry and resource management from the University of California at Berkeley and an M.S. degree in forestry from the University of Montana. On page 45, the description for the high load, dry climate shrub stated that "The moisture of extinction is high. " It was corrected to say "The moisture of extinction is low. " Robert E. Burgan retired as a SupervisoryYou may order additional copies of this publication by sending your mailing information in label form through one of the following media. Please specify the publication title and number.

You may order additional copies of this publication by sending your mailing information in label form through one of the following media. Please specify the publication title and series number. Fire managers are increasingly concerned about the threat of crown fires, yet only now are quantitative methods for assessing crown fire hazard being developed. Links among existing mathematical models of fire behavior are used to develop two indices of crown fire hazard-the Torching Index and Crowning Index. These indices can be used to ordinate different forest stands by their relative susceptibility to crown fire and to compare the effectiveness of crown fire mitigation treatments. The coupled model was used to simulate the wide range of fire behavior possible in a forest stand, from a low-intensity surface fire to a high-intensity active crown fire, for the purpose of comparing potential fire behavior. The hazard indices and behavior simulations incorporate the effects of surface fuel characteristics, dead and live fuel moistures (surface and crown), slope steepness, canopy base height, canopy bulk density, and wind reduction by the canopy. Example simulations are for western Montana Pinus ponderosa and Pinus contorta stands. Although some of the models presented here have had limited testing or restricted geographic applicability, the concepts will apply to models for other regions and new models with greater geographic applicability. Fort Collins Service Center

Wildfires can result in significant, long-lasting impacts to ecological, social, and economic systems. It is necessary, therefore, to identify and understand the risks posed by wildland fire, and to develop cost-effective mitigation strategies accordingly. This report presents a general framework with which to assess wildfire risk and explore mitigation options, and illustrates a process for implementing the framework. Two key strengths of the framework are its flexibility-allowing for a multitude of data sources, modeling techniques, and approaches to measuring risk-and its scalability, with potential application for project, forest, regional, and national planning. The specific risk assessment process we introduce is premised on three modeling approaches to characterize wildfire likelihood and intensity, fire effects, and the relative importance of highly valued resources and assets that could be impacted by wildfire. The spatial scope of the process is landscape-scale, and the temporal scope is short-term (that is, the temporal dynamics of succession and disturbance are not simulated). We highlight key information needs, provide guidance for use of fire simulation models and risk geo-processing tools, and demonstrate recent applications of the framework across planning scales. The aim of this report is to provide fire and land managers with a helpful set of guiding principles and tools for assessing and mitigating wildfire risk.

is a research forester in the Prescribed Fire and Fire Effects research work unit at the Intermountain Fire Sciences Laboratory in Missoula, MT. He received a B.S. degree in forestry from Washington State University and M.S. and Ph.D. degrees from the University of Montana. He has studied various aspects of forest ecology since 1963, including ecological site classifications, forest succession, fire history, fire effects, and the development of strategies for prescribed fire.

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...

Assessment of crown fire potential requires quantification of canopy fuels. In this study, canopy fuels were measured destructively on plots in five Interior West conifer stands. Observed canopy bulk density, canopy fuel load, and vertical profiles of canopy fuels are compared with those estimated from stand data using several computational techniques. An allometric approach to estimating these canopy fuel characteristics was useful, but, for accuracy, estimates of vertical biomass distribution and site-adjustment factors were required. Available crown fuel was estimated separately for each tree according to species, diameter, and crown class. The vertical distribution of this fuel was then modeled within each tree crown on the basis of tree height and crown base height. Summing across trees within the stand at every height yielded an estimated vertical profile of canopy fuel that approximated the observed distribution.

Exchange of self-assembled monolayers (SAMs) of dodecanethiol (C12H25SH) on gold with decanethiol (C10H21SH) was detected with laser-desorption Fourier transform mass spectrometry (LD-FTMS) in the negative ion mode. The amount of adsorption of C10H21SH is dependent on the extent of air oxidation of the C12H25SH SAM. In this study, a partially air oxidized C12H25SH SAM with a 2.2:1.5:1 ratio of dodecanethiolate (C12H25S-, m/z 201) to the presumed dodecanesulfinate (C12H25SO2 -, m/z 233) to dodecanesulfonate (C12H25SO3 -, m/z 249) on the surface is examined. After the sample is soaked in an ethanol solution of C10H21SH for 30 min, the LD-FTMS spectrum shows that both the C12H25SO2 - and the C21H25SO3 - are gone, but a decanethiolate peak appears (C10H21S-, m/z 173) in the same ratio to C12H25S- (1.19) as the ratio of the combined oxidation products (1.16) prior to soaking. Subsequent air exposure (9 h) of this SAM composed of mixed thiolates gives a similar ratio (1.06) of the fully oxidized sulfonates of both species, which can be completely removed upon subsequent soaking in a solution of C12H25SH, resulting in a SAM of pure dodecanethiolate by FTMS analysis. Negligible exchange occurs when nonoxidized C12H25SH SAMs are soaked in decanethiol solution for 30 min. From these observations, we draw several conclusions. First, the results refute suspicions that sulfonates form in a laser-induced reaction of thiolates with O2 absorbed in the SAM during air exposure. Second, ionization efficiency of thiolates and sulfonates during LD-FTMS analysis is approximately equal. Third, previous literature reports of exchange experiments should be carefully scrutinized for possible evidence of the effects of air oxidation.

Laser-induced breakdown spectroscopy (LIBS) is typically performed at ambient Earth atmospheric conditions. However, interest in LIBS in other atmospheric conditions has increased in recent years, especially for use in space exploration (e.g., Mars and Lunar) or to improve resolution for isotopic signatures. This review focuses on what has been reported about the performance of LIBS in reduced pressure environments as well as in various gases other than air.