腐殖质粒径和燃烧深度对兴安落叶松人工林地下火燃烧温度的影响

Effects of humus particle and combustion depth on combustion temperature of underground fires in Larix gmelinii plantations

地下火是森林中难以控制的一种燃烧现象,对森林危害极大,燃烧所释放的温度影响着地下火蔓延。以我国地下火频发区域之一的大兴安岭地区兴安落叶松(Larix gmelinii)人工林为研究对象,通过室内控制模拟点烧实验的方法,研究腐殖质粒径和燃烧深度对地下火燃烧温度的影响。结果表明:在不同地类条件下,不同粒径腐殖质和深度对燃烧最高温度的影响存在显著差异(P<0.05);在不同深度条件下,不同地类和腐殖质粒径以及二者的交互作用对燃烧最高温度的影响均存在显著差异(P<0.05);在5种地类的腐殖质中都以粒径≤80目和深度12cm处的燃烧温度最高;塔头甸子和水湿地条件下的地下火燃烧温度较高,尤其是塔头甸子;深度、距离和腐殖质粒径可作为有坡山地、水湿地和农用地条件下预测模型自变量,深度和腐殖质粒径可作为塔头甸子和无坡山地条件下预测模型自变量,且模型均通过了显著性检验(P<0.05)。相关研究成果可以为该地区地下火的防控和扑火装备的研发提供科学依据。

Underground fire is a kind of burning phenomenon which is difficult to control in the forest. It is very harmful to the forest. The temperature released by burning affects the spread of underground fire. Taking Larix gmelinii plantation in Daxing′anling area, one of the areas with frequent underground fire in China, as the research object, effects of humus particle size and combustion depth on the combustion temperature of underground fires were studied by the indoor control simulation of scorching experiment data. There were significant differences in the effects of different particle sizes and depths of humus on the maximum combustion temperature under different land classifications(P<0.05);there were significant differences in the effects of different land classifications, particle sizes of humus and their interaction on the maximum combustion temperature under different depths(P<0.05). Among five types of humus, the highest combustion temperature was at the particle size ≤80 mesh and the depth of 12 cm. The combustion temperature of underground fire was higher under the condition of tatoudianzi and meadow bog, especially in tatoudianzi. Depth, distance and humus particle size could be used as independent variables of the prediction model under the conditions of slope mountains, meadow bog and agricultural land, while depth and humus particle size could be used as independent variables of the prediction model under the conditions of tatoudianzi and flat mountains, and all the models passed the significance test(P<0.05). The results can provide scientific basis for the prevention and control of underground fire and the development of fire fighting equipment in this area.