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On 1 April 1963, the Department of Forest Fire Protection was established at the Forest Research Institute, which resulted from the need to develop scientific and organisational bases for building a forest fire protection system that would effectively minimise the growing fire hazard of Polish forests. The Department began its activities by developing a programme that took into account both the immediate but urgent needs of the forestry and the anticipated directions of research. Over the course of 60 years, more than 350 research reports were produced. Among the achievements that have influenced the currently functioning forest fire protection system in Poland there are: the method of forest fire risk assessment, forest fire risk prediction, the creation of fire risk monitoring based on a network of forest meteorological measuring points, the development of forest fuel models, the extensive use of aircraft to detect and extinguish forest fires, the conduct of the first studies on the possibility of using television cameras to detect forest fires, the operation of the National Forest Fire Information System, the purpose of which is to collect data on forest fires and natural non-forest areas, the development of an application for forest fire models and the conduct of the first workshop on controlled heath burn in the country. Among the many projects completed, there were also those dealing with the evaluation and suitability of equipment and chemicals for extinguishing forest fires. [ABSTRACT FROM AUTHOR]

We describe the development and implementation of an operational human-caused wildland fire occurrence prediction (FOP) system in the province of Ontario, Canada. A suite of supervised statistical learning models was developed using more than 50 years of high-resolution data over a 73.8 million ha study area, partitioned into Ontario's Northwest and Northeast Fire Management Regions. A stratified modelling approach accounts for different seasonal baselines regionally and for a set of communities in the Far North. Response-dependent sampling and modelling techniques using logistic generalized additive models are used to develop a fine-scale, spatiotemporal FOP system with models that include nonlinear relationships with key predictors. These predictors include inter- and intra-annual temporal trends, spatial trends, ecological variables, fuel moisture measures, human land-use characteristics, and a novel measure of human activity. The system produces fine-scale, spatially explicit maps of daily probabilistic human-caused FOP based on locally observed conditions along with point and interval predictions for the expected number of fires in each region. A simulation-based approach for generating the prediction intervals is described. Daily predictions were made available to fire management practitioners through a custom dashboard and integrated into daily regional planning to support detection and fire suppression preparedness needs. Key words: fire management, forest fire occurrence, person-caused, prediction interval, wildfire occurrence. Nous traitons du developpement et de la mise en oeuvre d'un systeme operationnel de prevision de l'occurrence des feux de foret (POF) d'origine humaine dans la province d'Ontario, au Canada. Une suite de modeles d'apprentissage statistique supervise a ete developpee en utilisant plus de 50 annees de donnees a haute resolution couvrant une aire d'etude de 73,8 millions d'hectares repartis dans les regions de gestion du feu du nord-ouest et du nord-est. Une approche de modelisation stratifiee tient compte a l'echelle regionale de differents niveaux de reference saisonniers et pour un ensemble de communautes de l'extreme nord. Des techniques de modelisation et d'echantillonnage dependantes de la reaction utilisant des modeles logistiques additifs generalises ont servi a elaborer un systeme de POF spatio-temporel a fine echelle avec des modeles qui incluent des relations non lineaires avec des variables predictives cles. Ces variables predictives incluent des tendances temporelles intra-annuelles, des tendances spatiales, des variables ecologiques, des mesures de teneur en humidite des combustibles, des caracteristiques de l'utilisation des terres par l'homme et une nouvelle mesure de l'activite humaine. Le systeme produit des cartes a fine echelle spatialement explicites qui illustrent la probabilite quotidienne de la POF d'origine humaine sur la base des conditions observees localement avec une prevision ponctuelle et un intervalle du nombre attendu de feux dans chaque region. Une approche fondee sur la simulation pour generer les intervalles de prevision est decrite. Les previsions quotidiennes ont ete mises a la disposition des responsables de la gestion du feu par l'entremise d'un tableau de bord personnalise et integrees dans la planification regionale quotidienne en support aux besoins de preparation pour la detection et la suppression des feux. [Traduit par la Redaction] Mots-cles: gestion du feu, occurrence des feux de foret, d'origine humaine, intervalle de prevision, occurrence des feux de vegetation., 1. Introduction 1.1. The need for and importance of fire occurrence prediction (FOP) systems Although the province of Ontario's forest fire management organization dates back as far as 1878 with [...]

Contemporary fire regimes of Canadian forests have been well documented based on forest fire records between the late 1950s to 1990s. Due to known limitations of fire datasets, an analysis of changes in fire-regime characteristics could not be easily undertaken. This paper presents fire-regime trends nationally and within two zonation systems, the homogeneous fire-regime zones and ecozones, for two time periods, 1959-2015 and 1980-2015. Nationally, trends in both area burned and number of large fires ([greater than or equal to]200 ha) have increased significantly since 1959, which might be due to increases in lightning-caused fires. Human-caused fires, in contrast, have shown a decline. Results suggest that large fires have been getting larger over the last 57 years and that the fire season has been starting approximately one week earlier and ending one week later. At the regional level, trends in fire regimes are variable across the country, with fewer significant trends. Area burned, number of large fires, and lightning-caused fires are increasing in most of western Canada, whereas human-caused fires are either stable or declining throughout the country. Overall, Canadian forests appear to have been engaged in a trajectory towards more active fire regimes over the last half century. Key words: fire regime, wildfire, trend analysis, Canadian forests. Les regimes contemporains des feux dans les forets canadiennes ont ete bien documentes selon les archives portant sur les feux de foret, accumulees depuis la fin des annees 1950 jusqu'aux annees 1990. A cause des limitations connues des jeux de donnees sur les feux, on ne pouvait facilement entreprendre une analyse des changements survenus dans les caracteristiques des regimes des feux. Cet article presente l'evolution des regimes des feux a l'echelle nationale et a l'interieur de deux systemes de zonage, la zone ou les regimes des feux sont homogenes et les ecozones, pour deux periodes, soit de 1959 a 2015 et de 1980 a 2015. A l'echelle nationale, dans les deux zones, les superficies brnlees et le nombre de grands feux ([greater than or equal to]200 ha) ont significativement augmente depuis 1959, ce qui pourrait etre du a une augmentation des feux causes par la foudre. Par contre, les feux d'origine humaine ont diminue. Les resultats indiquent que la taille des grands feux a augmente au cours des 57 dernieres annees et que la saison des feux debute environ une semaine plus tot et se termine une semaine plus tard. A l'echelle regionale, l'evolution des regimes des feux varie d'un endroit a l'autre et on observe moins de tendances significatives. Les superficies brUlees, le nombre de grands feux et les feux causes par la foudre sont en augmentation presque partout dans l'ouest du Canada, tandis que les feux d'origine humaine sont soit stables ou en diminution partout dans le pays. Dans l'ensemble, les forets canadiennes semblent engagees sur une trajectoire vers des regimes des feux plus actifs au cours des 50 dernieres annees. [Traduit par la Redaction] Mots-cles : regime des feux, feu de foret, analyse des tendances, forets canadiennes., 1. Introduction The fire-regime concept is composed of fire-related characteristics that describe the occurrence and impact of fires over space and time. In Canada, the fire regime is commonly characterized [...]

Historically, eastern ponderosa pine (Pinus ponderosa) forests were described as sparse patches of old-growth trees maintained by frequent, low-severity fires; however, in recent decades, there have been a number of large mixed-severity wildfires throughout the range of these forests. Wildlife responses to severe fire disturbance in eastern ponderosa pine forests are not well understood. Our study investigates how cavity-nesting bird species in an eastern ponderosa pine forest are impacted by burn severity. The objectives of our study were to: (1) identify the community composition of cavity-nesting birds in a 27 y old burn of mixed severity, (2) assess how habitat variables important to cavity-nesting birds differ in the mixedseverity fire, and (3) determine what habitat variables best predict bird occurrence 27 y after mixed-severity fire. We surveyed 56 sites across four burn severity classes, ranging from unburned to severely burned forest, in the Pine Ridge region of Nebraska. We measured multiple habitat characteristics (tree and snag diameter at breast height (DBH), coarse woody debris (CWD), tree and snag density, shrub height, and shrub cover) in May-August 2016 and conducted bird count surveys between 25 May and 8 June 201 (i. Cavity-nesting bird species' occurrence varied among the burn severity variables. Burn severity class (unburned, low severity, moderate severity, high severity) was a significant predictor of habitat characteristics for cavity-nesting birds, including tree density, snag density, mean snag DBH, variance in DBH, and (AVI), which also was the best indicator of cavity-nesting bird community composition. We report evidence that mixed-severity wildfires in eastern ponderosa pine forests create variation in habitat characteristics and cavity-nesting bird occurrence., INTRODUCTIONWildfire is a major ecological disturbance that can alter community composition and vegetation structure (Brown and Sieg, 1999; Hutto et al., 2016). Although ponderosa pine (Pinus ponderosa) forests are believed [...]

In the managed forest of Canada, forest fires are actively suppressed through efficient initial attack capability; however, the impact of different factors on the suppression success remains to be understood. The aim of this paper was to analyze the influence of operational suppression objectives (fire detection, initial attack, and fire control) along with fire intensity, fuel type, fire ignition cause, year, workload, and homogeneous fire regime zones on the achievement of the fire suppression objective (fire < 3 ha) using the Forest Fire Protection Agency of Quebec (SOPFEU) as a case study. The overall success of the suppression objective was very high (88%) over the study period (1994–2015). Both detection and control had significant effects on the suppression success through their interaction with fuel type, ignition cause, fire intensity, and zone variables. When the suppression objective was not achieved, final fire size was influenced by control, fuel type, fire intensity, and zone. The paper highlights the importance of the operational objectives and of regional differences for both fire suppression success and final fire size. Our results can help forest fire protection agencies to better understand their wildland fire suppression systems for a better adaptation to the upcoming fire regime changes. [ABSTRACT FROM AUTHOR]

We computed four stand-level canopy stratum variables important for crown fire modelling – canopy cover, stand height, canopy base height and canopy bulk density – from forest inventory data. We modelled the relationship between the canopy variables and a set of common inventory parameters – site index, stem density, basal area, stand age or stand height – and number of prescribed burns. We used a logistic model to estimate canopy cover, a linear model to estimate the other canopy variables, and the information theoretic approach for model selection. Coefficients of determination across five forest groups were 0.72–0.91 for stand height, 0.36–0.83 for canopy base height, 0.39–0.80 for canopy cover, and 0.63–0.78 for canopy bulk density. We assessed crown fire potential (1) for several sets of environmental conditions in all seasons, and (2) with increasing age, density and number of prescribed burns using our modelled canopy bulk density and canopy base height variables and local weather data to populate the Crown Fire Initiation and Spread model. Results indicated that passive crown fire is possible in any season in Atlantic coastal plain pine stands with heavy surface fuel loads and active crown fire is most probable in infrequently burned, dense stands at low fuel moistures. We developed equations estimating canopy characteristics from commonly measured inventory variables and used estimated canopy base height and bulk density in a model to assess potential for crown fire at increasing age, density and number of prescribed burns. Findings indicate potential for active crown fire in dense stands at low fuel moistures. [ABSTRACT FROM AUTHOR]

The present work addresses the problem of how wind should be taken into account in fire spread simulations. The study was based on the software system FireStation, which incorporates a surface fire spread model and a solver for the fluid flow (Navier-Stokes) equations. The standard procedure takes the wind field computed from a single simulation in the absence of fire, but this may not be the best option, especially for large fires. The two-way coupling method, however, considers the buoyancy effects caused by the fire heat release. Fire rate of spread is computed with the semi-empirical Rothermel model, which takes as input local terrain slope, fuels properties and wind speed and direction. Wind field is obtained by solving the mass, momentum and energy equations. Effects of turbulence on the mean flow field are taken into account with the k - ε turbulence model. The calculation procedure consists of an interchange between the fire spread model and the wind model through a dynamic interaction. The present work describes the first part of this research, presenting the underlying models and a qualitative sensitivity analysis. It is shown that the update frequency for the dynamic interaction markedly influences the total calculation time. The best strategy for updating the wind field during the fire progression is presented. The dependence of results on mesh size is also described. [ABSTRACT FROM AUTHOR]

There are few studies on the effects of fire on the seasonal semideciduous forest of the Cerrado region. This study aimed to assess the effect of fire on Semideciduous forest fragments located in the Altamiro Moura Pacheco State Park (AMPSP). The study area is located in the central state of Goiás. A total of 10 plots (50 x 20 m; 1,000 m²) were drawn in the remaining forests seeking to portray two areas: area which underwent forest fire (burned area; B) and unburned area (unburned; UB). A total of 771 individuals with DBH (≥ 5 cm) were identified. A total of 303 individuals were recorded in the burned area (B), comprising 28 families, 41 genera and 47 species, while the unburned area (UB) had 468 individuals comprising 25 families, 43 genera and 50 species. The species Anadenanthera colubrina (Vell.) Brenan, Emmotum nitens (Benth.), Zanthoxylum rhoifolium Lam, Tapirira guianensis Aubl., Myracrodruon urundeuva Allemão and Luehea candicans Mart. had the highest Importance Value Index (IVI) values and occur in both areas. The percentage of dead trees differed between the areas, where the burned area had a mortality of 12.69% and the unburned area of 7.29% in regards to the number of individuals. Density per plot was the only parameter that differed between the areas, where the burned area (B) had the lowest values. The fire affected all diameter classes, demonstrating the fragility of this vegetation type in regards to fire. The fire had a greater effect on trees in the smaller diameter classes, reducing the frequency of individuals in the burned area and changing height distribution, which may have favored the establishment of lianas and invasive species. [ABSTRACT FROM AUTHOR]

Near-instantaneous estimation of the moisture content of live fuels is complicated because of the large control exerted by physiological mechanisms. The commonly accepted reference method for measuring fuel moisture content is oven drying, which is time consuming. This study evaluates the use of a moisture analyzer (ML-50, A&D Company, Limited, Tokyo, Japan) for measuring the foliar moisture content of two common European species. The moisture of live leaves of Arbutus unedo L. (strawberry tree) and Quercus robur L. (pedunculate oak) was measured within a period of 15 min using two drying temperatures and compared with the oven-dried value. Correction factors were determined for estimating the oven-dried moisture content based on the measurement by the moisture analyzer. The power delivered during the drying process plays an important role in the moisture measured by the analyzer in relation to the oven-dried value. Increasing the drying time beyond the minimum period necessary for obtaining a reliable prediction of the oven-dried moisture does not significantly change the moisture measured at lower temperatures. The moisture analyzer is able to estimate the live foliage moisture content with high accuracy. Key words: fuel moisture content, live fine fuels, correction equations. L'estimation quasi instantanee de la teneur en humidite des combustibles vivants est compliquee a cause du grand controle exerce par les mecanismes physiologiques. La methode de reference generalement acceptee pour mesurer la teneur en humidite des combustibles est le sechage au four qui demande du temps. Cet article evalue un analyseur d'humidite (ML-50, A&D Company Ltd) pour mesurer la teneur en humidite des feuilles de deux especes europeennes communes. La teneur en humidite des feuilles vivantes dArbustus unedo L. (arbousier) et de Quercus robur L. (chene pedoncule) a ete mesuree pendant une periode de 15 min en utilisant deux temperatures de sechage et comparee a la valeur obtenue par sechage au four. Des facteurs de correction ont ete determines pour estimer la teneur en humidite par sechage au four a partir des mesures obtenues avec l'analyseur. La puissance fournie durant le processus de sechage a un effet important sur la teneur en humidite mesuree par l'analyseur en relation avec la valeur obtenue par sechage au four. Le fait d'augmenter le temps de sechage au-dela de la periode minimale requise pour obtenir une prediction fiable de la teneur en humidite selon la methode de sechage au four ne change pas de facon significative la teneur en humidite mesuree a des temperatures plus faibles. L'analyseur d'humidite est capable d'estimer la teneur en humidite du feuillage vivant avec une grande precision. [Traduit par la Redaction] Mots-cles: teneur en humidite des combustibles, combustibles legers vivants, equations de correction., Introduction Fuel moisture content measures the amount of water in the fuel, normally expressed as a percentage of its dry mass. It plays a key role in forest fire behaviour [...]

Assessing burn severity is critical for understanding both the short- and long-term effects of fire disturbance on forest ecosystems. This study proposed a methodology to reconstruct burn severity from the Landsat imagery at different time lags after a fire (≤18 years) in Siberian larch (Larix sibirica) forest. The estimated accuracy of the burn severity models we developed indicated strong effects of forest recovery, image acquisition date and remote sensing predictors on the burn severity assessment. In the first several years after the fire, the dNBR (differenced Normalized Burn Ratio) was the most important remotely sensed index for assessing burn severity, followed by the dNDMI (differenced Normalized Difference Moisture Index) and dNDVI (differenced Normalized Difference Vegetation Index). However, the dNDMI was more important than the dNBR and dNDVI in explaining burn severity when larch forest regrowth dominated. The overall accuracy of the classification and regression tree models showed a decrease in accuracy from 83% to 62% depending on the lag times of burn severity assessment. The high severity class had the lowest omission and commission errors, followed by the low and moderate classes among lag times. Our evaluation of model transferability and thresholds of burn severity index demonstrates the advantage of the proposed methodology for rapid assessment of fire effects in boreal larch forest that will assist in understanding the complex relationships among forest fires and ecological processes in Eurasian boreal ecosystems. [ABSTRACT FROM AUTHOR]

The European beech (Fagus sylvatica L.) is one of the most ecologically and economically important tree species in Europe. Nonetheless, post-fire ecological processes in beech forests have only been marginally studied although they might become more important for forest management in the light of global climate change drought effects. Focusing on the Southern European Alps, where numerous forest fires have affected beech stands, we assessed temporal trends and detected factors that influence beech regeneration in beech forests burnt between 1970 and 2012. Beech regeneration was found to occur abundantly in fire sites of mixed burn severity, and often co-occurred with light-demanding pioneer trees (mostly Betula pendula Roth). These pioneers declined in abundance from 20 years post-fire onwards, whereas beech dominance increased. Beech regeneration density was best explained in regression models by the canopy of remnant trees and the abundance of competing ground vegetation. As fire-injured beech trees slowly die back, the canopy gradually opens, favouring beech recruitment for as long as decades, depending on the light conditions. In contrast, dense layers of early post-fire colonisers may delay beech regeneration for many years. Generally, single fire events favour beech regeneration except in areas where the burn severity is extraordinarily high. [ABSTRACT FROM AUTHOR]

Measured soil moisture data may improve wildfire probability assessments because soil moisture is physically linked to fuel production and live fuel moisture, yet models characterising soil moisture-wildfire relationships have not been developed. We therefore described the relationships between measured soil moisture (concurrent and antecedent), as fraction of available water capacity (FAW), and large (≥405 ha) wildfire occurrence during the growing (May-October) and dormant (November-April) seasons from 2000 to 2012 in Oklahoma, USA. Wildfires were predominantly grass and brush fires but occurred across multiple fuel types including forests. Below-average FAW coincided with high wildfire occurrence each season. Wildfire probability during the growing season was 0.18 when concurrent FAW was 0.5 (a threshold for plant water stress) but was 0.60 when concurrent FAW was 0.2 (extreme drought). Dormant season wildfire probability was influenced not only by concurrent but also by antecedent FAW. Dormant season wildfire probability was 0.29 and 0.09 when FAW during the previous growing season was 0.9 (near ideal for plant growth) and 0.2, respectively. Therefore, although a wet growing season coincided with reduced wildfire probability that season, it also coincided with increased wildfire probability the following dormant season, suggesting that the mechanisms by which soil moisture influences wildfire probability are seasonally dependent. [ABSTRACT FROM AUTHOR]

The article offers forest research news briefs. Uneven-aged forestry unites Swedish and Finnish researchers. A study published in Scientific Reports on nature.com analyses regional fires and their links to regional temperature, precipitation and sea surface temperatures of the Northern Atlantic. Press releases are considered to be important by journalists.

We applied logistic regression and Random Forest to evaluate drivers of fire occurrence on a provincial scale. Potential driving factors were divided into two groups according to scale of influence: 'climate factors', which operate on a regional scale, and 'local factors', which includes infrastructure, vegetation, topographic and socioeconomic data. The groups of factors were analysed separately and then significant factors from both groups were analysed together. Both models identified significant driving factors, which were ranked in terms of relative importance. Results show that climate factors are the main drivers of fire occurrence in the forests of Fujian, China. Particularly, sunshine hours, relative humidity (fire seasonal and daily), precipitation (fire season) and temperature (fire seasonal and daily) were seen to play a crucial role in fire ignition. Of the local factors, elevation, distance to railway and per capita GDP were found to be most significant. Random Forest demonstrated a higher predictive ability than logistic regression across all groups of factors (climate, local, and climate and local combined). Maps of the likelihood of fire occurrence in Fujian illustrate that the high fire-risk zones are distributed across administrative divisions; consequently, fire management strategies should be devised based on fire-risk zones, rather than on separate administrative divisions. [ABSTRACT FROM AUTHOR]

On 30 May 2013, a forest fire occurred in Izmir, Turkey causing damage to both forest and fruit trees within the region. In this research, pre- and post-fire SPOT-6 images obtained on 30 April 2013 and 31 May 2013 were used to identify the extent of forest fire within the region. SPOT-6 images of the study region were orthorectified and classified using pixel and object-based classification (OBC) algorithms to accurately delineate the boundaries of burned areas. The present results show that for OBC using only normalized difference vegetation index (NDVI) thresholds is not sufficient enough to map the burn scars; however, creating a new and simple rule set that included mean brightness values of near infrared and red channels in addition to mean NDVI values of segments considerably improved the accuracy of classification. According to the accuracy assessment results, the burned area was mapped with a 0.9322 kappa value in OBC, while a 0.7433 kappa value was observed in pixel-based classification. Lastly, classification results were integrated with the forest management map to determine the effected forest types after the fire to be used by the National Forest Directorate for their operational activities to effectively manage the fire, response and recovery processes. [ABSTRACT FROM PUBLISHER]

Fire has a major impact on the structure and function of many ecosystems globally. Pyrodiversity, the diversity of fires within a region (where diversity is based on fire characteristics such as extent, severity, and frequency), has been hypothesized to promote biodiversity, but changing climate and land management practices have eroded pyrodiversity. To assess whether changes in pyrodiversity will have impacts on ecological communities, we must first understand the mechanisms that might enable pyrodiversity to sustain biodiversity, and how such changes might interact with other disturbances such as drought. Focusing on plant-pollinator communities in mixed-conifer forest with frequent fire in Yosemite National Park, California, we examine how pyrodiversity, combined with drought intensity, influences those communities. We find that pyrodiversity is positively related to the richness of the pollinators, flowering plants, and plant-pollinator interactions. On average, a 5% increase in pyrodiversity led to the gain of approximately one pollinator and one flowering plant species and nearly two interactions. We also find that a diversity of fire characteristics contributes to the spatial heterogeneity ( β-diversity) of plant and pollinator communities. Lastly, we find evidence that fire diversity buffers pollinator communities against the effects of drought-induced floral resource scarcity. Fire diversity is thus important for the maintenance of flowering plant and pollinator diversity and predicted shifts in fire regimes to include less pyrodiversity compounded with increasing drought occurrence will negatively influence the richness of these communities in this and other forested ecosystems. In addition, lower heterogeneity of fire severity may act to reduce spatial turnover of plant-pollinator communities. The heterogeneity of community composition is a primary determinant of the total species diversity present in a landscape, and thus, lower pyrodiversity may negatively affect the richness of plant-pollinator communities across large spatial scales. [ABSTRACT FROM AUTHOR]

Plant communities are sensitive to perturbations and may display alternative recovery pathways depending on disturbance history. In sub-boreal lodgepole pine forests of central interior British Columbia, Canada, fire and logging are two widespread landscape disturbances that overlap in many regions. We asked whether cumulative, short-interval disturbance from logging and fire resulted in different ground-layer plant communities than resulted from fire alone. Using field-collected data, we compared the taxonomic composition and functional traits of 3-year old plant communities that were either harvested 6-to-13 years prior, or not harvested prior to being burned in a large stand-replacing fire. The taxonomic composition diverged between the two treatments, driven primarily by differences in a few key indicator species such as Petasites frigidus and Vaccinium membranaceum. Analysis of individual species' morphological traits indicated that only a few species vary in size in relation to disturbance history. Our data suggest that a history of forest harvest leaves a subtle footprint on post-fire ground-layer plant communities at early stages of succession. [ABSTRACT FROM AUTHOR]

Fires are a key disturbance of boreal forests. In fact, they are the main source of renewal and evolution for forest stands. The variability of fire through space and time results in a diversified forest mosaic, altering their species composition, structure and productivity. A resilient forest is assumed to be in a state of dynamic equilibrium with the fire regime, so that the composition, age structure and succession stages of forests should be consistent with the fire regime. Dense spruce-moss stands tend, however, to diminish in favour of more open stands similar to spruce-lichen stands when subjected to more frequent and recurring disturbances. This study therefore focused on the effects of spatial and temporal variations in burn rates on the proportion of open stands over a large geographic area (175,000 km²) covered by black spruce (Picea mariana (Mill.) Britton, Sterns, Poggenb.). The study area was divided into 10 different zones according to burn rates, as measured using fire-related data collected between 1940 and 2006. To test if the abundance of open stands was unstable over time and not in equilibrium with the current fire regime, forest succession was simulated using a landscape dynamics model that showed that the abundance of open stands should increase progressively over time in zones where the average burn rate is high. The proportion of open stands generated during a specific historical period is correlated with the burn rate observed during the same period. Rising annual burn rates over the past two decades have thereby resulted in an immediate increase in the proportion of open stands. There is therefore a difference between the current proportion of open stands and the one expected if vegetation was in equilibrium with the disturbance regime, reflecting an instability that may significantly impact the way forest resources are managed. It is apparent from this study that forestry planning should consider the risks associated with the temporal variability of fire regimes on the forest ecosystem, as the resulting changes can have a significant impact on biodiversity and allowable cut estimates. [ABSTRACT FROM AUTHOR]

This study proposes and evaluates a relatively new concept for fire occurrence zoning based on documented historical fire records. The proposed method creates continuous kernel density surfaces based on wildland fire ignition observations. Kernels have the advantage of directly producing density estimates that are not influenced by grid size or localization effects. Within this scheme, kernel density surfaces have been created and reclassified to construct fire occurrence zones at local to global scales in the Mediterranean Basin. Specifically, fire occurrence zones were created for the European scale (European Mediterranean Basin), national scale (Greece), regional scale (Peloponnese, Greece) and local scale (Chalkidiki, Greece). To evaluate fire occurrence zones, we compared the observed with the expected distribution of the number of fires within these zones using a Monte Carlo randomization test, finding that these numbers were statistically different in all cases. The deviations observed from the expected distributions towards the high occurrence zone indicated their successful assessment and value. In this paper, we further discuss their potential role and use for multi-scale fire management and policy in a European context. [ABSTRACT FROM AUTHOR]

Fire is the most common disturbance in northern boreal forests, and large fires are often associated with highly variable burn severities across the burnt area. We studied the understory plant community response to a range of burn severities and pre-fire stand age four growing seasons after the 2011 Richardson Fire in xeric jack pine forests of northern Alberta, Canada. Burn severity had the greatest impact on post-fire plant communities, while pre-fire stand age did not have a significant impact. Total plant species richness and cover decreased with disturbance severity, such that the greatest richness was in low severity burns (average 28 species per 1-m² quadrat) and plant cover was lowest in the high severity burns (average 16%). However, the response of individual plant groups differed. Lichens and bryophytes were most common in low severity burns and were effectively eliminated from the regenerating plant community at higher burn severities. In contrast, graminoid cover and richness were positively related to burn severity, while forbs did not respond significantly to burn severity, but were impacted by changes in soil chemistry with increased cover at pH >4.9. Our results indicate the importance of non-vascular plants to the overall plant community in this harsh environment and that the plant community is environmentally limited rather than recruitment or competition limited, as is often the case in more mesic forest types. If fire frequency and severity increase as predicted, we may see a shift in plant communities from stress-tolerant species, such as lichens and ericaceous shrubs, to more colonizing species, such as certain graminoids. [ABSTRACT FROM AUTHOR]

Remotely sensed data have already become one of the major resources for estimating the burn severity of forest fires. Recently, Land Surface Temperature (LST) calculated from remote sensing data has been considered as a potential indicator for estimating burn severity. However, using the LST-based index alone may not be sufficient for estimating burn severity in the areas that has unburned trees and vegetation. In this paper, a new index is proposed by considering LST and enhanced vegetation index (EVI) together. The accuracy of the proposed index was evaluated by using 264 composite burn index (CBI) field sample data of the five fires across different regional eco-type areas in the Western United States. Results show that the proposed index performed equally well for post-fire areas covered with both sparse vegetation and dense vegetation and relatively better than some commonly-used burn severity indices. This index also has high potential of estimating burn severity if more accurate surface temperatures can be obtained in the future. [ABSTRACT FROM AUTHOR]

Lightning-caused forest fires can cause serious damage to the social economy and public property and even threaten human life. Therefore, lightning-caused forest fire risk rating assessment is very important for forest management agency, because the risk rating assessment results could provide important information to prevent fires and allocate extinguishing resources. The existing forest fire risk rating assessment methods are more difficult for the area with sparse meteorological stations, imperfect lightning monitoring systems and complex terrain conditions. Based on remote sensing data and case-based reasoning principle, this paper proposed a method to overcome the limitations of existing forest fire risk rating assessment methods. The proposed method uses three dynamic and two static indexes to characterize the potential fire environment. The dynamic indexes are temperature condition index, vegetation condition index and water condition index. The static indexes are terrain fluctuation and LIS/OTD lightning density. In DaXingAn Mountains of China, the fire risk rating spatial distribution maps with 8-day cycle before the occurrences of historical lightning-caused fires were produced by using the lightning-caused forest fire risk rating assessment method during 2000-2006 in this paper. The results showed that most of the historical lightning-caused fires occurred in the region with high fire risk rating, and the spatial-temporal distribution changes of the lightning-caused fire risk rating followed the same trend as the changes in the number of lightning-caused fires. Therefore, the lightning-caused forest fire risk rating assessment method proposed in this paper could assess the fire risk rating effectively, and this method could also provide a reference for other countries and regions with sparse meteorological stations and imperfect lightning monitoring systems. [ABSTRACT FROM AUTHOR]

Boreal soils account for ~ 30% of the global soil organic carbon (C) stock. Wildfires are an important perturbation of this C pool, particularly affecting the top organic soil layer, which constitutes the forest floor. Alterations to the forest floor by fire are relevant to the soil C balance and have profound implications for soil properties. However, relationships between forest floor transformations and actual wildfire characteristics have not been established to date due to the logistical challenges of obtaining the necessary fire behaviour data, together with associated pre- and post-fire sample material. We used a high-intensity experimental wildfire to address this research gap, which enabled us to determine forest floor chemical transformations in a Canadian boreal forest in relation to temperature–time profiles for 18 sampling points during the fire. Forest floor samples taken pre- and post-fire were characterized using elemental and δ 13 C analysis, differential scanning calorimetry and 13 C nuclear magnetic resonance. During this typical boreal crown fire average maximum temperature (T max ) at the forest floor was 745 °C (550 < T max < 976 °C) with the average heating duration (t) > 300 °C being 176 s (65 < t < 364 s). Significant correlations were detected between the chemical characteristics of the pyrogenic (charred) forest floor layer and the temperature–time profiles at the corresponding sampling points. Higher T max and associated prolonged heating durations correlated with greater C enrichments, increased thermal recalcitrance and degree of aromaticity of the pyrogenic organic matter. These changes were particularly pronounced for T max > 600–700 °C, which is higher than the range of 300–500 °C for aromaticity development previously reported from laboratory experiments. One reason for this discrepancy could be the generally much longer heating durations used in laboratory studies, and we therefore advise caution when extrapolating findings from laboratory studies to wildfire conditions. Almost half of the initial total C stock in the forest floor (20 Mg C ha − 1 ) was affected by fire, with ~ 24% of this fire-affected C transformed to pyrogenic organic matter. This pyrogenic material possessed variable, yet distinct, chemical characteristics when compared to unburnt forest floor, including higher recalcitrance and associated resistance to biological degradation. As some boreal regions already show a rise in fire severity and area burned linked to climate change, our findings suggest a potential accompanying increase in the more stable organic carbon stock, with important implications for the functioning and turnover of organic matter in boreal soils. [ABSTRACT FROM AUTHOR]

Forest fire is one of the dominant disturbances in boreal forests. It is the primary process responsible for organizing the physical and biological attributes of the boreal biome, shaping landscape diversity and influencing biogeochemical cycles. The Greater Hinggan Mountain of China is rich in forest resources while suffers from a high incidence of forest fires simultaneously. In this study, focusing on the most serious forest fire in the history of P. R. China which occurred in this region, we made use of two Landsat-5 TM (Thematic Mapper) images, and proposed to map the overall burned area and burned forest area by multiple methods. During the mapping, the fire perimeter, as well as rivers, roads and urban areas were first extracted and masked visually, and then four indices of Normalized Difference Vegetation Index, Enhanced Vegetation Index, Vegetation Fractional Cover and Disturbance Index were calculated. For each index, the optimal threshold for separating burned from unburned forest area was determined using their histograms. For comparison, threshold segmentation using single-band reflectance was performed, in addition to a Maximum Likelihood Classifier (MLC) based supervised classification of all features and forest area alone; their accuracies were also evaluated and analysed. Among all the methods compared here, mapping by EVI threshold segmentation proved to be optimal by the comparisons of overall accuracy (99.78%) and the kappa coefficient (0.9946). Finally, the calculated burned area and burned forest area were compared with the values from official statistics. Compared with the classical methods used to report official statistics on burned areas, the remote sensing-based mapping is more objective and efficient, less labour- and time-consuming, and more repeatable. [ABSTRACT FROM PUBLISHER]

Wildfires are keystone components of natural disturbance regimes that maintain ecosystem structure and functions, such as the hydrological cycle, in many parts of the world. Consequently, critical surface freshwater resources can be exposed to post-fire effects disrupting their quantity, quality and regularity. Although well studied at the local scale, the potential extent of these effects has not been examined at the global scale. We take the first step toward a global assessment of the wildfire water risk (WWR) by presenting a spatially explicit index of exposure. Several variables related to fire activity and water availability were identified and normalized for use as exposure indicators. Additive aggregation of those indicators was then carried out according to their individual weight. The resulting index shows the greatest exposure risk in the tropical wet and dry forests. Intermediate exposure is indicated in mountain ranges and dry shrublands, whereas the lowest index scores are mostly associated with high latitudes. We believe that such an approach can provide important insights for water security by guiding global freshwater resource preservation. [ABSTRACT FROM AUTHOR]

On 4 and 8 January 2014, at the height of the austral summer, intense wildfires in forests and dry pastures occurred in the Melipilla sector, located about 70 km to the southwest of Santiago, the Chilean capital, affecting more than 6 million inhabitants. Low level winds transported the forest fire plume towards Santiago causing a striking decrease in visibility and a marked increase in the concentration of both primary (PM10 and CO) and secondary (Ozone) pollutants in the urban atmosphere. In particular, ozone maximum concentrations in the Santiago basin reached hourly averages well above 80 ppb, the national air quality standard. This ozone increase took place at the three sampling sites considered in the present study. These large values can be explained in terms of high NOx concentrations and NO2/NO ratios in biomass burning emissions. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the response of the soil microarthropod community to wildfire in forest ecosystems. The edaphic microarthropod communities of pine stands burned in 2001, in 2009, both in 2001 and in 2009, in 2012 were compared to an area never burned. Sampling was conducted in the spring and autumn of 2011 and 2012 in the areas burned in 2001, in 2009 and those never burned, while in the area burned in 2012, soil samples were collected in March (10 days after fire), June and September. The abundance and biodiversity of the microarthropod community were assessed. A multitemporal analysis was also carried out to assess the effect of fire on soil microarthropod abundance 5 months, 2-3 years and 10-11 years after fire. The results showed that the abundance of edaphic microarthropod communities decreased dramatically in areas burned twice, but also in areas burned once in 2009 and five months after the fire in the area burned in 2012. Different taxonomic groups did not seem to respond to fire in the same way, some taxa being more sensitive than others. Pseudoscorpionida decreased in both the shortand the long-term, while Diplopoda, Thysanoptera and Symphyla showed a reduction in the intermediate- and long-term. In the short-term, Diptera and Coleoptera larvae appeared to be the most influenced taxonomic groups. Our study shows that biomonitoring is a valuable tool to investigate the reaction of forest ecosystems to fire, and that edaphic microarthropods can provide interesting answers about the direct and indirect effects of fire on soil. [ABSTRACT FROM AUTHOR]

In the scenario of the Mediterranean area, where about 54 000 fires and 0.4 million hectares of forest are burned and annually registered (2006-2010), the rank for Algeria is non-negligible with 4.11 million hectares of forest. The annual number of fires and the size of area burned depict a critical situation, which became rather dramatic in 2012. Climate change projections and the estimated changes to wildfire risk for the future decades (2030-2060) indicate that the entire Maghreb region, including Algeria, will be among the most affected areas of the Mediterranean. Longer fire seasons will be experienced and extended by an additional month with each passing year. Despite Algeria's recent investments in technical means for controlling forest fires, the current suppression-oriented model seems unable to cope with such a phenomenon. Furthermore, the model is unfit in view of the approaching scenario, when fire-exclusion policies need to be complemented with fuel-reduction techniques and fire prevention management. This study aims to establish an understanding of the context and public policy issues related to wildfire management in Algeria. Data were collected by distributing questionnaires to foresters with the objective of identifying obstacles and constraints hindering the efficacy of pro-active measures. Analysis of the data gathered indicates that Algerian foresters are well aware of the importance of prevention, contrasting with current governmental policies that are predominantly oriented towards improving the technical extinction apparatus. A SWOT analysis suggests possible strategic options for improving the efficiency of wildfire control by building on strengths, eliminating weaknesses, exploiting opportunities, and mitigating threats. The results of this study may be adapted to other countries with similar problems as those of Algeria. [ABSTRACT FROM AUTHOR]

Wildfires cause devastating environmental, social and economic effects in different regions of the world. The aim of this study was to analyze the long-run relationship between the number of ignition events and socioeconomic variables using time series data. We focus on Galicia, a region in the northwest part of the Iberian Peninsula and with one of the highest fire density and largest burned areas in Europe. Since the late 1980s, the number of forest fires has increased in Galicia and caused extensive damage to the environment, property and human life. The analysis is based on cointegration tests between variables. In order to avoid the problems related to spurious regression, the ARDL bounds testing approach was applied. The statistical evidence allows us to conclude that in the long term, the price of eucalyptus timber, the population in the primary sector and the intensity of the elections are relevant factors in explaining the start of forest fires. These three variables are found to increase the propensity of the population to start a fire that cause devastating environmental, social and economic effects. [ABSTRACT FROM AUTHOR]

Mixed-severity fire regimes may be the most extensive yet poorly understood fire regimes of western North America. Understanding their long-term spatiotemporal dynamics is central to debates regarding altered fire regimes and the need for restoration in the context of changing climate and nearly a century of active fire suppression. However, the complexity of fire patterns and forest stand and landscape structures characteristic of mixed-severity regimes poses a substantial challenge to understanding their long-term dynamics. In this study, we develop analysis methods aimed at understanding the fire-driven forest dynamics of mixed-severity systems and apply them in the San Juan Mountains of southwestern Colorado. We sampled fire scars, stand structure, and >4300 tree ages across two 1340-ha landscapes (Williams Creek and Squaretop Mountain) that span the environmental gradient of montane mixed-conifer and aspen forests. New approaches were applied to identify pulses of tree recruitment, evaluate climate and fire as potential drivers of synchronous recruitment pulses, and combine fire scar and recruitment data to reconstruct fires. The reconstructions provided detailed fire history for each stand, which in turn was used to develop a fire-severity metric, compare fire frequency and severity by forest type, and develop a simulation procedure to evaluate the degree to which tree regeneration depended on fire by species within each forest type. Twenty fires were reconstructed since 1685 at Williams Creek and 13 fires since 1748 at Squaretop Mountain. Patterns of fire severity varied within each fire and over successive events, including high-severity patches of hundreds of hectares in both study areas. Dry mixed-conifer forests experienced relatively short fire intervals (mean 21 years) and low fire severity, and regeneration of the main conifer species was largely dependent on open conditions sustained over successive fires. Moist mixed-conifer forests experienced longer fire intervals (mean 32 years) and a broader range of severities, and fire-caused canopy openings were important for initiating pulses of tree recruitment. Most (83%) aspen stands included two or more post-fire cohorts. The methods presented here can be adapted to other mixed-severity systems to better understand their long-term spatial and temporal dynamics and develop restoration priorities. [ABSTRACT FROM AUTHOR]

The Brazilian Cerrado is significantly affected by anthropic fires every year, which makes the region an important source of pyrogenic emissions. This study aims at generating improved 1 km monthly burned area maps for Cerrado based on remote-sensed information. The algorithm relies on a burn-sensitive vegetation index based on MODIS daily values of near and middle infrared reflectance and makes use of active fire detection from multiple sensors. Validation is performed using reference burned area (BA) maps derived from Landsat imagery. Results are also compared with MODIS standard BA products. A monthly BA database for the Brazilian Cerrado is generated covering the period 2005-2014. Estimated value of BA is 1.3 times larger than the value derived from reference data, making the product suitable for applications in fire emission studies and ecosystem management. As expected the intra and inter-annual variability of estimated BA over the Brazilian Cerrado is in agreement with the regime of precipitation. This work represents the first step towards setting up a regional database of BA for Brazil to be developed in the framework of BrFLAS, an R and D project in the areas of fire emissions and ecosystem management planning. [ABSTRACT FROM AUTHOR]

Presented is the method of computational monitoring of black carbon emissions due to wildfires. The computation is carried out for the territory of Russia for the period of 2007-2012. Given is the distribution of black carbon emissions according to fire types and regions. The mean value of black carbon emission due to wildfires for the period under consideration amounted to 81.9 ± 37.2 × 10 t/year and interannual variations are from 53.8 × 10 t in 2011 to 143.5 × 10 t in 2008. The mean value of black carbon emission in the forests is 25.0 ± 3.7 kg/ha for crown fires, 24.0 ± 0.1 kg/ha for underground fires, 10.2 ± 1.2 kg/ha for ground fires, and 4.1 ± 0.3 kg/ha for fires in non-forested areas. [ABSTRACT FROM AUTHOR]

The majority of wildfires in the Republic of Croatia occur in coastal and island areas, so the Šibenik-Knin County was studied in this research. This research was based upon spatial and temporal analyses of past fires in the Šibenik-Knin County using GIS tools in order to identify potential locations for seasonal dislocation of fire stations. The research resulted in cartographic visualization of areas within reach of existing fire brigades within the standard intervention time and potential locations for seasonal dislocation of fire stations. The results obtained using spatial GIS analysis can be used as a basis for future spatial planning and seasonal dislocation of fire stations in the Šibenik-Knin County, as well as a basis for determining dislocation of fire stations in other Croatian counties. [ABSTRACT FROM AUTHOR]

Background: Anthropogenic uses of fire play a key role in regulating fire regimes in African savannas. These fires contribute the highest proportion of the globally burned area, substantial biomass burning emissions and threaten maintenance and enhancement of carbon stocks. An understanding of fire regimes at local scales is required for the estimation and prediction of the contribution of these fires to the global carbon cycle and for fire management. We assessed the spatio-temporal distribution of fires in miombo woodlands of Tanzania, utilizing the MODIS active fire product and Landsat satellite images for the past ~40 years. Results: Our results show that up to 50.6% of the woodland area is affected by fire each year. An early and a late dry season peak in wetter and drier miombo, respectively, characterize the annual fire season. Wetter miombo areas have higher fire activity within a shorter annual fire season and have shorter return intervals. The fire regime is characterized by small-sized fires, with a higher ratio of small than large burned areas in the frequency-size distribution (β = 2.16 ± 0.04). Large-sized fires are rare, and occur more frequently in drier than in wetter miombo. Both fire prevalence and burned extents have decreased in the past decade. At a large scale, more than half of the woodland area has less than 2 years of fire return intervals, which prevent the occurrence of large intense fires. Conclusion: The sizes of fires, season of burning and spatial extent of occurrence are generally consistent across time, at the scale of the current analysis. Where traditional use of fire is restricted, a reassessment of fire management strategies may be required, if sustainability of tree cover is a priority. In such cases, there is a need to combine traditional and contemporary fire management practices. [ABSTRACT FROM AUTHOR]

Unlike the commonly used relative humidity, vapor pressure deficit (VPD) is an absolute measure of the difference between the water vapor content of the air and its saturation value and an accurate metric of the ability of the atmosphere to extract moisture from the land surface. VPD has been shown to be closely related to variability in burned forest areas in the western United States. Here, the climatology, variability, and trends in VPD across the United States are presented. VPD reaches its climatological maximum in summer in the interior southwest United States because of both high temperatures and low vapor pressure under the influence of the northerly, subsiding eastern flank of the Pacific subtropical anticyclone. Maxima of variance of VPD are identified in the Southwest and southern plains in spring and summer and are to a large extent driven by temperature variance, but vapor pressure variance is also important in the Southwest. La Niña-induced circulation anomalies cause subsiding, northerly flow that drives down actual vapor pressure and increases saturation vapor pressure from fall through spring. High spring and summer VPDs can also be caused by reduced precipitation in preceding months, as measured by Bowen ratio anomalies. Case studies of 2002 (the Rodeo-Chediski and Hayman fires, which occurred in Arizona and Colorado, respectively) and 2007 (the Murphy Complex fire, which occurred in Idaho and Nevada) show very high VPDs caused by antecedent surface drying and subsidence warming and drying of the atmosphere. VPD has increased in the southwest United States since 1961, driven by warming and a drop in actual vapor pressure, but has decreased in the northern plains and Midwest, driven by an increase in actual vapor pressure. [ABSTRACT FROM AUTHOR]

As fire is a major disturbance in boreal forests, it is now recognized that it has to be taken into account in forest management planning. Moreover, as the time of exposure to fire is related to stand productivity, combining information on productivity and fire should help in assessing the potential to sustainably manage forests. We present a method to assess potential vulnerability to the risk of fire and illustrate it in the boreal coniferous forest of Quebec. This method takes into account some sources of uncertainty related to the estimation of productivity and fire risk. Spatialization of stand productivity from growth and yield curves allowed us to compute the area comprised of productive stands of each district with or without considering fire risk. Results showed that productive area is generally decreasing with decreasing degree-days, increasing elevation, or in relation to surficial geology. Furthermore, districts with moderate to good productivity were found to be vulnerable to fire when burn rates were greater than 0.333%·year-1. Our innovative approach allowed us to assess the vulnerability of the districts to fire and could be helpful in many regions in the context of a projected increase in future area burned under climate change. [ABSTRACT FROM AUTHOR]

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents the results of studying the Cladonia lichen postfire growth-rate dynamics in different zonal units of West Siberia. The relative growth rate of lichens in forest-tundra and taiga zones was assessed with regard to the pyrogenic factor. The growth rate varied from 1.2 mm/year at the early stage of recovery succession to 11.9 mm/year at the stage of the closed lichen cover. The variations in lichen growth rates at different stages of recovery were reliable in southern and middle taiga communities. In open forests and forest-tundra communities of northern regions, the growth rate of lichens was not characterized by significant changes. [ABSTRACT FROM AUTHOR]

In this work the influence of external environmental factors (prevailing forest stands, intensity of the fire season, and weather conditions) on power released by fire (fire radiative power (FRP)) has been studied. The data from the Moderate Resolution Imaging Spectroradiometer (MODIS) are used to characterize variations of the FRP. Our studies show that, during periods of high fire activity, the FRP is 10% higher than during periods of low fire activity. The correlation level between the FRP and weather fire danger is determined. In particular, the fire weather index (FWI) of the Canadian weather fire-danger-assessment system shows a closer relationship with the FRP than the Russian PV-1 index. Based on the results, it is found that fires in forests with a predominance of larch have higher FRP values (by 20-25%) for the forest zone of Siberia than fires in deciduous and pine forests. [ABSTRACT FROM AUTHOR]