武夷山国家公园内4种森林类型地表可燃物热值特征比较

Comparison of surface fuel calorific value characteristics of four forest types in Wuyishan National Park

森林可燃物是森林火灾燃烧的物质载体和必要条件.以武夷山国家公园4种森林类型中的7种林分下地表可燃物为研究对象,分析地表可燃物热值特征及其内部差异.结果表明:4种森林类型地表可燃物热值在阳坡和阴坡上多数无显著差异(P> 0.05),不同龄级马尾松林活地表可燃物、阔叶林死地表可燃物和马尾松近成熟林10 h时滞可燃物(10hr)在阳坡和阴坡存在显著差异(P <0.05).同一森林类型下活地表可燃物和死地表可燃物之间的热值多数差异显著,同一大类地表可燃物内部差异不显著(除毛竹林外).地表可燃物在7种林分间热值存在差异,活地表可燃物(17.95-19.87k J/g)和死地表可燃物(18.09-20.09k J/g)热值较高.马尾松林不同演替阶段,10hr无显著差异,灌木、草本和1hr在不同演替阶段存在显著差异.马尾松幼龄林和马尾松中龄林热值高灰分低;毛竹林、马尾松成过熟林热值低灰分高.可见地表可燃物热值受地形、林分、林龄等因素的综合影响,结果可为该区域森林林火模型构建和森林可燃物精准管理提供参考.

Forest fuel is the material carrier and indispensable condition for forest fire occurrence.Surface fuel for seven stands of four forest types in Wuyishan National Park was studied to analyze their calorific value characteristics and internal differences.The results showed that most of the calorific value of the surface fuel had no significant difference on the sunny and shady slopes of the four forest types(P>0.05).A significant difference between the sunny and shady slopes occurred in the living surface fuel of different ages of Pinus massoniana forests,dead surface fuel of broad-leaved forests,and 10 h dead fuel of near-mature P.massoniana forests(P<0.05).In the same forest type,most of the calorific values were significantly different between live and dead surface fuel,and there was no significant difference within the same surface fuel(except for bamboo forest).The calorific value of the surface fuel was different among the seven forest stands.The calorific value was relatively high in the living surface fuel(17.95-19.87 kJ/g)and dead surface fuel(18.09-20.09 kJ/g).In the different successive stages of Pinus massoniana,the calorific value of 10 h dead fuel was not significantly different,whereas that of the shrubs,herbs,and 1 h dead fuel was notable.Surface fuel with high caloric value and low ash content was found in young P.massoniana forest and middle-aged P.massoniana forest,whereas surface fuels with low caloric value and high ash content were found in bamboo forest and mature and overmature P.massoniana forests.Therefore,the calorific values of surface fuels are comprehensively affected by topography,forest stand,and forest age,which provides a reference for the construction of forest fire models and the precise management of forest fuels.