秦岭火地塘林区4种林分地被物林火蔓延特性研究

Fire Spread Properties of Four Forest Litters at Huoditang Forest Region in the Qinling Mountains

以秦岭火地塘林区油松、华山松、锐齿栎和落叶松 4种林分地被物为研究对象 ,测定了 4种林分地被物在春季防火期林火蔓延指标随含水率的变化趋势及其灭火含水率 ,在此基础上计算各林分地被物的水分贮量、潜在能量、能量释放和火强度指标。结果表明 :4种林分地被物含水率最小值分别保持在 6.8% ,8.9% ,8.4%和 4.7%左右 ;在一定的范围内 ,4种地被物含水率与林火蔓延速度之间均呈密切的指数相关关系 ,其灭火含水率分别是 36.8%、36.3%、2 8.3%和 30 .3% ;华山松和油松两种林分地被物潜在能量明显高于锐齿栎和落叶松林。临近灭火含水率时 ,锐齿栎林分地被物所释放的能量分别是华山松和油松的 42 .3%和 43.6% ,落叶松则为 2 9.7%和 30 .6% ,并且 4种林分地被物火强度指标分别降低了 87.8%、86.4%、86.4%和 90 .6%。

Fire spread index of litters in the sharptooth oak, armand pine, chinese pine and larix principis rupprechtii forests and their variation with moisture content were measured in the spring season. The relationship between moisture content and fire spread index was analyzed using no liner regression, and also the water storage, potential energy, energy release and fire intensity index were calculated on the basis of measured date. The results showed that obvious index relationship was exist between moisture content of litters and their spread velocity. The minimum moisture content of four litters are about 6.8%,8.9%,8.4% and 4.7% respectively, and the extinguishing moisture content were 36.8%,36.3%,28.3% and 30.3, the potential energy of armand pine and chinese pine were higher than sharptooth oak and larix principis rupprechtii, energy release of sharptooth oak and larix principis rupprechtii were only 42.3% ,43.6% and 29.7%, 30.6% respectively compared with chinese pine and armand pine. Fire intensity for their litters decreased about 87.8%、86.4%、 86.4 % and 90.6 % in the range of minimum moisture content to extinguishing moisture content.