大娄山典型林分地表细小死可燃物载量影响因子研究

Influencing factors of surface fine dead fuel loading in typical forest stands of Dalou Mountain

【目的】森林地表细小死可燃物作为森林火灾的引火物,其载量决定一系列火行为和火灾发生的危险程度,快速准确地获取地表细小死可燃物载量值对于森林火险预报和林火科学管理具有重要意义。【方法】本研究以西南林区大娄山6种典型林分(马尾松林、软阔林、柏木林、杉木林、阔叶混交林和灌木林)地表细小死可燃物为研究对象,通过野外调查和室内烘干,测定林分特征和载量值,得到地表细小可燃物载量的影响因子,并建立预测模型。【结果】1)不同林型地表细小死可燃物载量存在显著差异,马尾松林和阔叶混交林显著高于其他林分。马尾松林和阔叶混交林的不同标准地间载量差异显著,其余林分不同标准地间的载量均无显著差异;2)除杉木林和灌木林外,其他林分的地表细小死可燃物载量与某些林分特征因子(林龄、郁闭度、平均胸径、平均树高、平均地径、坡度和海拔)均有显著相关性,林分密度和平均冠幅对研究区地表细小死可燃物载量无显著影响;3)建立马尾松林、柏木林、软阔林、阔叶混交林的地表细小死可燃物载量预测模型,柏木林预测效果最好,误差仅为3.6%,马尾松林预测误差高达27.4%,不能在实际中应用。【结论】通过本研究可获取大娄山典型林分的地表细小死可燃物载量基础数据,并得到影响因子和预测模型,对于该区域载量研究和林火科学管理具有重要意义。

【Objective】As the igniter of forest fire,the loading of fine dead fuel on the forest surface determines a series of fire behaviors and the risk degree of fire occurrence.It is of great significance for forest fire risk prediction and scientific forest fire management to quickly and accurately obtain the loading value of fine dead fuels on the surface.【Method】In this study,the fine dead fuel on the surface of 6 typical forests(Pinus massoniana Lamb.forest,Cupressus funebris Endl.forest,Soft broad forest,Cunninghamia lanceolata forest,Broadleaf mixed forest and shrub forest)in Dalou Mountain in the southwest forest region were taken as the research object.Through field investigation and indoor drying,the forest characteristics and loading values were measured to obtain the influencing factors of the fine dead fuel on the surface,and a prediction model was established.【Result】1)The fine dead fuel loading of different forest types was significantly different,and that of Pinus massoniana Lamb.and Broadleaf mixed forest was significantly higher than that of other forests.The difference in carrying capacities between different standard plots of Pinus massoniana Lamb.forest and broadleaf mixed forest was significant,and there was no significant difference in carrying capacities among different standard plots of other stands;2)Except for Cunninghamia lanceolata forest and shrub forest,the surface fine dead fuel loading of other forests had a significant correlation with some forest characteristic factors(forest age,canopy density,mean diameter at breast height,mean tree height,mean diameter at ground level,slope and elevation).The forest density and average crown width had no significant impact on the surface fine dead fuel loading of the study area;3)The prediction model of the surface fine dead fuel loading of Pinus massoniana Lamb.forest,Cupressus funebris Endl.forest,soft broad forest and Broadleaf mixed forest was established.The prediction effect of Cupressus funebris Endl.forest was the best,with an error of only 3.6%.The prediction error of Pinus massoniana Lamb.forest was as high as 27.4%,which could not be applied in practice.【Conclusion】Through this study,the basic data of the surface fine dead fuel loading of typical forest stands in Dalou Mountain and the influencing factors and prediction models have been obtained,which is of great significance for the study of the regional loading and scientific forest fire management.