DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu



ŠUMARSKI LIST 11-12/2015 str. 66     <-- 66 -->        PDF

characteristics (Anderson, 1982; Chandler et al. 1983; Pyne et al. 1996; Nelson, 2001; Bilgili & Saglam, 2003; Bilgili et al. 2006; Kucuk et al. 2012). A fuel model describes a complex of fuel elements through their average properties values (Burgan & Rothermel, 1984). Therefore, a fuel model is based on the physical rather than the floristic characteristics of a fuel complex and a single fuel model can be applied to various vegetation types whose fuel characteristics are similar to those represented by the model (Dimitrakopoulos, 2002).
The National Forest Fire Laboratory (NFFL) fire behavior fuel models (Anderson, 1982) provide a general framework to describe the surface fuel complex in temperate regions. The NFFL set of fuel models is often used in Europe, e.g. ICONA (1990). However, realistic estimates of fire characteristics for structurally different fuel types require specific fuel models. European examples include fuel models for Alpine (Allgöwer et al. 1998) and Mediterranean (Dimitrakopoulos, 2002; Cruz & Fernandes, 2008; Fernandes, 2009; Krivtsov et al. 2009) vegetation types. Although fuel models should be fine-tuned with observed fire behavior data in order to adequately reflect real-world fire characteristics (Burgan & Rothermel, 1984), such procedure is seldom followed (Cruz & Fernandes, 2008), which can have negative impacts on the conclusions reached by fire modeling exercises and application to fire management decisions.
Selecting, calibrating or developing fuel models and determining their fire behavior potential are of crucial importance in fire, forest, and land management in the Mediterranean region. In this study, fuel models calibrated with observed fire behavior characteristics were for the first time developed for important fuel types in Turkey and their potential fire behavior range then determined using the BehavePlus fire modeling system.
METHODS
Metode
Fuel characteristics and fire behavior experiments – Karakteristike govora i eksperimenti ponašanja požara
In this study we considered four fuel types, respectively slash of Anatolian black pine (P. nigra J.F. Arnold subsp. nigra var. caramanica (Loudon) Rehder), black pine litter, low maquis, and tall maquis. Taken together, these fuel types represent nearly half of Turkey’s wildland area, 19.8 % corresponding to black pine and 27% to maquis (OGM, 2006).
Kastamonu was the study area for Anatolian black pine slash. Slash of three different ages (3, 12, 24 month) at two fresh fuel loading levels (8 kg m–2 and 16 kg m–2) was used. Fuels in the burning plots (3x1 m) were made up of foliage and branches. A series of 30 burning plots were established on level terrain occupied by newly cut black pine slash fuels. Fuel was uniformly distributed to the greatest extent possible. The plots were laid out in parallel, in the direction of the prevailing wind. Fuel material within one 0.09 m2 (30x30 cm) sampling frame was removed from each plot down to the mineral soil, and then sorted into needles and branches, later subdivided by size class. Fuel depth was measured as the vertical distance from the litter layer bottom to the slash top, at three points in each plot with a ruler. During the experimental burns, 2-m open wind speed, air temperature and relative humidity were recorded at 15-second intervals using an automatic weather station set up at the site edge. The wind measurements were averaged over the fire spread period. Plots were burned over two years under varying temperature, relative humidity, moisture and wind speed conditions (Küçük et al. 2008).
Fuel modeling for the black pine litter fuel bed was conducted in a 45 year-old stand with an average diameter at breast height (dbh) of 30 cm, average live crown base height of 6 m, and an average height of 18 m, averaging 700 stem ha–1. No living plants were present in the understorey and living trees made up 100% of the overstorey. Surface fuels consisted primarily of needle litter along with some branches and cones. Surface fuel loading measurements were based on three fuel samples randomly taken immediately adjacent to each burning plot. Surface fuel material within a 30x30 cm sampling frame was removed down to mineral soil, and then sorted into litter (needles, branches) and duff. Burn plots in black pine litter (n=28) were established on flat terrain and measured 3x1 m (3 m long and 1 m wide) and were laid out, in parallel, in the direction of the prevailing wind for subsequent line ignition. The plots were surrounded by cleared fire lines (0.5 m width) so that each plot would burn free from the influence of other fires (Kucuk et al. 2007).
Fuel models were also built for low (< 1-m tall) and tall maquis (> 1-m tall). Shrub fuels are most common in the southwestern of Turkey. The study areas were located in Antalya and Keşan. The dominant plant species were Quercus coccifera L. for low maquis and Arbutus andrachne L. and Pistacia lentiscus L. for tall maquis. A detailed description is included in Saglam et al (2008a, 2008b). A series of 18 burning plots were established at the experimental burning sites. The size of each plot was 0.06 ha (20 × 30 m), delimited by a 5-m wide fire-break bulldozed to mineral soil to enable easy access and facilitate fire control. A complete fire weather station was established on the site 10 days prior to the burnings. Air temperature, relative humidity, 2-m open wind speed and precipitation were recorded at 13:00 local standard time.
The shrub fuel parameters measured for fuel modeling were height, fuel loading by size class and condition (dead or alive), and the moisture contents of dead fine fuel and live