Fire behaviour in slahs fuel of thinned black pine (Pinus nigra Arnold.) forests

Forest fires generally start from the surface fuel in the forest. In this study, a total of 33 small scale surface fires were ignited under weather and fuel conditions within thinned Anatolian black pine (P. nigra J.F. Arnold subsp. nigra var. caramanica (Loudon) Rehder) stands. Surface fuels consisted generally of thinned material (needle+branches). In the thinned Black pine forest stands, total surface fuel loading ranged from 3,0 to 10,2 kg m–². Wind speed ranged from 0,3 km h-¹ to 8,4 km h-¹. Fine fuel (<0,6 cm in diameter) moisture content changed from 10% to 21%. Relationships between the rate of fire spread, fire intensity and fuel and weather conditions were determined through correlation and regression analyses. The rate of fire spread ranged from 0,47 to 6,92 m min–1 in the surface fires. Fire line intensity ranged from 173 to 10239 kW m-1. Wind speed was the most important factor on both rate of spread and fire line intensity and explained 71% of the observed variation in the surface fire rate of spread and 74% of the observed variation in fire line intensity. These results should be invaluable for the prediction of surface fire behavior and the management of surface fuels in pine stands.