烟头引燃藏柏林下尖叶匐灯藓层研究

Study on cigarette butts igniting a Plagiomnium acutum layer in the understory of a Cupressus torulosa forest

为研究地表苔藓层的引燃特性,以昆明地区广泛分布的藏柏林下地被物尖叶匐灯藓为研究对象,在室内模拟构造野外自然生长状态的尖叶匐灯藓床层,设定5个水平含水率(0%、5%、10%、15%、20%)以及6个水平风速(0、1、2、3、4、5 m·s^(-1))的烟头引燃藏柏林下尖叶匐灯藓层试验。结果表明:烟头引燃尖叶匐灯藓层的最大含水率约为20%;含水率和风速以及两个因子之间的相互作用对尖叶匐灯藓层的引燃比例有显著影响。当风速≤2 m·s^(-1)时,尖叶匐灯藓层不能被烟头引燃;当风速从3 m·s^(-1)增加到5 m·s^(-1)时,含水率从20%降至0%时,烟头的引燃比例从13%增至82%。建立了烟头引燃尖叶匐灯藓层的二元Logistic回归模型,预测的准确率达71.7%。研究结果可为昆明地区地表可燃物的管理、火险预警等提供依据,为深入开展苔藓植物的火灾风险辨识与评价奠定基础。

To study the igniting characteristics of surface moss layers,Plagiomnium acutum,which is widely distributed in the understory of Cupressus torulosa forest in Kunming,Yunnan Province,China,was selected as the research species.In the laboratory,cigarette butts was placed onto the Plagiomnium acutum bed,which was constructed to simulate how it grows naturally in the field.We examined the Plagiomnium acutum layer under five moisture content levels(0%,5%,5%,10%,15%,20%)and six wind speeds(0,1,2,3,4,5 m·s^(-1)).The results showed that:the highest moisture content at which the Plagiomnium acutum layer could be ignited by the cigarette butts was approximately 20%.Water content,wind speed and the interaction between the two factors have significant effects on the ignition proportion of the layer.When the wind speed was less than 2 m·s^(-1),the layer could not be ignited by cigarette butts.When the wind speed increased from 3 m·s^(-1) to 5 m·s^(-1) and the moisture content of the layer decreased from 20%to 0%,the ignition proportion of cigarette butts increased from 13% to 82%.A binary Logistic regression model established for the Plagiomnium acutum layer ignited by cigarette butts had a prediction accuracy of 71.7%.The results of this study can provide a basis for the management of surface forest fuels and fire risk warnings in the Kunming area and lay a foundation for further research on forest fire risk identification and the evaluation of moss.