Fire risk in Austrian pine (Pinus nigra) plantations under various temperature and wind conditions (original) (raw)

RATES OF SURFACE FIRE SPREAD IN A YOUNG CALABRIAN PINE (Pinus brutia Ten.) PLANTATION

Environmental Engineering and Management Journal, 2012

Fire behaviour data and models are essential in modern fire management. Thirty five experimental line-ignited fires were carried out in a young calabrian pine (Pinus brutia Ten.) stand with the objective of modelling the rate of surface fire spread. Relationships between rate of fire spread, and fuel, weather and topographical conditions were established by correlation and regression analyses. Dead fine fuel loading ranged from 0.19 to 0.68 kg m-2. Rate of fire spread varied from 0.3 to 3.75 m min-1 and flame length ranged from 5 cm to 55 cm. Rate of fire spread equations were generated that described the relationships of spread rate with fuel and weather conditions, using linear regression models. Wind speed had a dominant effect on rate of surface fire spread and explained 72% (P < 0.01) of the observed variation.

Modeling surface fire rate of spread within a thinned Anatolian black pine stand in Turkey

Forest Systems

Aim of the study: To develop regression models for estimating the rate of surface fire spread in a thinned even-aged black pine stand (Pinus nigra J.F. Arnold subsp. nigra var. caramanica (Loudon) Rehder).Area of the study: The study was carried out within a thinned black pine forest located in the Kastamonu Forest District, northwestern Turkey. The study area is located at 546819, 4577880 UTM.Material and methods: A total of 33 small scale surface fires were ignited under varying weather and fuel conditions. Line ignition was used during the burnings. Surface fuels consisted generally of thinned material (needle+branches).Main results: Within the stand, surface fuel loading ranged from 3.0 to 10.2 kg/m2. Wind speed ranged from 0.3 to 8.4 km/h. Needle moisture content ranged from 8 to 15%. The rate of fire spread ranged from 0.47 to 6.92 m/min. Relationships between the rate of fire spread and fuel and weather conditions were determined through regression analyses.Research highlight...

Forest Fire Studies on Fire Behaviour: Key Topics and Their Importance

INCOS2018, 2018

Every year thousands of hectares of forest fires occur in Mediterranean countries and there are major damages. The effects of forest fires are quite extensive when considered from the organism to landscape level in the short term and long term. Forest fires show different behaviours depending on where they come from and the factors that affect it with the flammable materials. Forest fire triangles provide important framework to study the forest fires. Flammable materials can be changed and controlled by time and space. Therefore, they are separated from meteorological and topographic factors that cannot be controlled. The main types of forest fire are ground, surface and crown fire. These types of fire reveal differences in terms of the danger and its fighting. In this study, the main topics of forest fire behaviour and fuel model researches and their importance will be present. The research of forest fire requires the need to study in very different areas. The studies required for the development of fire propagation and fuel models in fire management systems is gradually increasing. Estimations of typical forest fire features such as fire propagation ratio, fuel consumption, fire intensity, and flame size utilize fuel loading values, as well as spatial heterogeneity, which affects these factors. A significant feature of forest fire risk analyses is the fact that cause-based ignition, fire behaviour, and fire management have multivariate uncertainty factors. All of these research needs are basic components of the fire decision support system, which is a essential prerequisite of an effective fire management system.

Study of a forest fire behaviour in changed wind speed conditions

Košická bezpečnostná revue, 2018

Forest fires represent threat mostly in countries situated in temperate climate zone, however, because of the changing climate, longer periods of high temperatures and drought, we can expect that their number and extent will increase in Slovakia, too. There are several factors influencing the initiation and further propagation of forest fire. Among the most important factors belong the volume and type of fuel available, topography, meteorological conditions and the time of fire. Those influence mostly the fire propagation, i.e. fire behaviour. In the paper, we introduce the results of a study focusing the fire behaviour in changing wind speed conditions. To model the fire behaviour, the FARSITE software was applied. In the modelling, we applied the data on real forest fire that occurred in the Slovensky Raj National Park, Koc locality in 2007. We modelled the fire behaviour for 24 h, using the specific wind speeds (0 km/h, 34 km/h, 68 km/h). According to the modelling results, we an...

Fire development from a point source in surface fuels of a mature Anatolian black pine stand

Turkish Journal of Agriculture and Forestry, 2007

A total of 28 line and 24 point-source fires were ignited under varying weather and fuel loading conditions in Anatolian black pine (Pinus nigra J.F.Arnold subsp. nigra var. caramanica (Loudon) Rehder) stands. Relationships between the rate of fire spread and fuel and weather conditions were determined with correlation and regression analyses. The rate of fire spread ranged from 0.12 to 1.20 m min-1 in line fires. In the ignition, transition, and steady state phases of point-source fires, the rate of fire spread ranged from 0.04 to 0.78 m min-1 , from 0.11 to 0.59 m min-1 , and from 0.08 to 0.99 m min-1 , respectively. Surface fuel loading ranged from 1.27 to 2.45 kg m-2 for line fire and from 1.56 to 2.67 kg m-2 for point-source fire. The results showed that the rate of fire spread was closely related to wind speed and fuel moisture content for line and point-source fires. The linear prediction for wind conditions estimates that equilibrium spread rates may be achieved within 25 min after the ignition of pointsource fires.

Empirical modelling of surface fire behaviour in maritime pine stands

International Journal of Wildland Fire, 2009

An experimental burning program took place in maritime pine (Pinus pinaster Ait.) stands in Portugal to increase the understanding of surface fire behaviour under mild weather. The spread rate and flame geometry of the forward and backward sections of a line-ignited fire front were measured in 94 plots 10-15 m wide. Measured head fire rate of spread, flame length and Byram's fire intensity varied respectively in the intervals of 0.3-13.9 m min −1 , 0.1-4.2 m and 30-3527 kW m −1 . Fire behaviour was modelled through an empirical approach. Rate of forward fire spread was described as a function of surface wind speed, terrain slope, moisture content of fine dead surface fuel, and fuel height, while back fire spread rate was correlated with fuel moisture content and cover of understorey vegetation. Flame dimensions were related to Byram's fire intensity but relationships with rate of spread and fine dead surface fuel load and moisture are preferred, particularly for the head fire. The equations are expected to be more reliable when wind speed and slope are less than 8 km h −1 and 15 • , and when fuel moisture content is higher than 12%. The results offer a quantitative basis for prescribed fire management.

Susceptibility to Fire (Case the Forest of Chettabah, Algeria)

This work consists to evaluate the sensitivity of the Holm oak and Aleppo pine forestry vegetation against the fire in the region of Constantine (north-east Algerian). The shrub and herbaceous stratums are the most vulnerable and inflammables. The parameters analysis and the follow up of the foliage water content of the flammability and the combustibility is achieved during whole the year on the evergreen oak, Aleppo pine and a few number of secondary kinds of its floristic accompanying. The sensitivity of the foliage depend on the species, it is optimal during the summer. The time of flammability varies between 30 and 120 seconds in winter, even though the combustibility is between 40 and 500 seconds for the same periods. Theses variations allows to get noticed of the homogeneous groups for the litter, the bark and the other species like Asparagus acutifolium, Astragalus armatus Calycotome spinosa Ampelodesma mauritanicum, Cistus villosus, Pistacia lentiscus and Arbutus unedo. A classification of the different vegetables species is established according to studied parameters of the sensitivity degree. The air maximum temperature of the month is the hottest and is varied between (39-42°C). During the summer, the flammability is 60 seconds for Pinus halepensis and 20 seconds for Quercus ilex concerning the combustibility; it oscillates respectively between 200-400 seconds and 200-300 seconds for the two forestry species. The risk calculation by the CEMAGREF method is higher in the summer. The combustibility knowledge of the flammability is due to the foliage water content, linked to the species and the vegetable formation that are transposable for the vegetation map which allowed to class the planting by big flammability categories. Keywords: susceptibility to fire, Holm oak, Aleppo pine, water content, flammability, combustibility risk.

Fire behaviour and severity in a maritime pine stand under differing fuel conditions

Annals of Forest Science, 2004

An experimental fire was conducted in the summer in a 28-year old maritime pine (Pinus pinaster) plantation in northeastern Portugal. Fuel conditions within the stand were age-dependent and comprised four situations: treated with prescribed fire at differing times, respectively 2, 3, and 13 years before the study, and undisturbed, where fuel accumulation time equalled stand age. The rate of fire spread did not respond to factors other than wind speed, in spite of the fuel-complex diversity. A high-intensity fire involving partially or totally the tree canopy and killing all trees was experienced in the older treatment area and in the untreated part of the stand, but the benefits of fuel management were still detectable in the former. Surface fire intensity, crown fire potential and fire severity (including tree mortality) were drastically reduced where prescribed fire had been carried recently. Fuel and fire management implications are discussed. fire behaviour / fire severity / experimental fire / fuel management / Pinus pinaster Résumé-Comportement et sévérité d'un feu dans un peuplement de pin maritime pour des conditions de végétation variées. Un feu expérimental a été réalisé pendant l'été dans une plantation de pin maritime (Pinus pinaster) âgé de 28 ans, situé au Nord-Est du Portugal. Les conditions du combustible dans le peuplement étaient dépendantes de la période d'accumulation, avec quatre situations; trois traitées avec brûlage dirigé en différents moments, respectivement 2, 3, et 13 ans avant l'étude, et une jamais traitée, où le temps d'accumulation de combustible était égal à l'âge du peuplement. Malgré la diversité des caractéristiques du combustible, la vitesse de propagation du feu n'a été influencée que par la vitesse du vent. La partie du peuplement traitée 13 ans auparavant et celle non traitée ont connu un feu d'une intensité élevée, qui a touché partiellement ou totalement le couvert arboré et tué tous les arbres, mais les effets bénéfiques du traitement furent encore décelables dans la partie brûlée antérieurement. En revanche, l'intensité du feu de surface, le potentiel à engendrer un feu de cime et la sévérité du feu (y compris la mortalité des arbres) ont été fortement réduits dans les zones où un brûlage dirigé avait été conduit récemment. Les conséquences en terme de gestion du combustible et du feu sont discutées. comportement du feu / sévérité du feu / feu experimental / gestion du combustible / Pinus pinaster

Ignition characteristics of forest species in relation to thermal analysis data

Thermochimica Acta, 2002

The ignitability of various forest species was measured with a specifically designed apparatus, under precisely controlled temperature and airflow conditions. The ignitability tests were based on ignition delay time versus temperature measurements using five different forest species: Pinus halepensis, Pistacia lentiscus, Cupressus sempervirens, Olea europaea, Cistus incanus. These species are common in the Mediterranean region and frequently devastated by forest fires. The ignition characteristics of the forest fuels examined were related to thermogravimetric analysis data. The DTG curves showed that the mass changes related to cellulose decomposition in the temperature range of 320-370 8C are greatly responsible for the ignition behavior of the species tested. In addition, the mass of volatiles evolving between 120-160 8C has a significant effect on the ignitability. On the contrary, the inorganic ash content of forest fuels, measured by atomic absorption spectroscopy, seems to play an insignificant role on the ignitability characteristics of the forest fuels examined.