基于热重分析的大兴安岭乔灌木树种燃烧性

Combustibility of tree and shrub species in Da Xing’an mountains based on thermogravimetric analysiss

【目的】热重分析是研究森林可燃物热解过程和其潜在燃烧性的重要方法。测定大兴安岭塔河地区的主要乔灌木树种的皮、枝、叶的热解参数,并对热解动力学参数进行燃烧性排序,为森林防火树种选择和建立相应的林火行为模型提供依据。【方法】以13种乔木的皮、叶以及7种灌木的枝与叶为研究对象,利用热重分析仪得到热解动力学相应参数,通过计算得到活化能和指前因子,对主要乔灌木的不同部位的活化能以及热解参数进行燃烧性分析。【结果】乔木树皮的活化能在4.342~8.601 kJ·mol^(-1),树叶的活化能在3.956~10.226 kJ·mol^(-1);灌木枝的活化能在3.832~8.258 kJ·mol^(-1),灌木叶的活化能在4.238~6.635 kJ·mol^(-1);根据主成分研究结果表明13种乔木树种的树皮的燃烧性由高到低依次为:钻天柳皮>花楸皮>甜杨皮>兴安落叶松皮>蒙古栎皮>黑桦皮>白桦皮>樟子松皮>山杨皮>赤杨皮>鱼鳞云杉皮>红松皮>红皮云杉皮;树叶的燃烧性由高到低依次为:钻天柳叶>甜杨叶>花楸叶>蒙古栎叶>黑桦叶>山杨叶>白桦叶>兴安落叶松叶>赤杨叶>樟子松叶>鱼鳞云杉叶>红松叶>红皮云杉叶。7种灌木枝的燃烧性由高到低为越桔枝>兴安圆柏枝>榛子枝>偃松枝>胡枝子枝>杜香枝>笃斯越桔枝。灌木叶的燃烧性由高到低为:胡枝子叶>榛子叶>笃斯越桔叶>兴安圆柏叶>越桔叶>杜香叶>偃松叶。【结论】根据主要乔灌木的燃烧性,表明该地区的乔木中红皮云杉抗火性最佳,灌木中笃斯越桔抗火性最佳,且灌木相较于乔木燃烧性更强,为该地区生物防火树种选择提供依据。

【Objective】Thermogravimetric analysis is an important method to study the pyrolysis process and potential combustibility of forest combustibles.The pyrolysis parameters and pyrolysis kinetic parameters of the bark and leaves of the main trees and shrubs in Tahe county of the Da Xing’an mountains were sorted by combustibility,which provided a basis for selecting fire-resistant tree species and establishing the corresponding forest fire behavior model.【Method】Taking the barks and leaves of 13 kinds of trees as well as the leaves and branches of 7 kinds of shrubs as the research objects,the corresponding parameters of pyrolysis kinetics were obtained by thermogravimetric analysis instrument,and the activation energy and preexponential factor were obtained by calculation.The combustibility analysis of different parts of the main trees and shrubs was carried out by using the activation energy and pyrolysis parameters.【Result】The activation energy of tree barks was between 4.342-8.601 kJ·mol^(-1),the activation energy of leaves was between 3.956^(-1)0.226 kJ·mol^(-1),the activation energy of shrub branches was 3.832-8.258 kJ·mol^(-1),and the activation energy of shrub leaves was between 4.238 and 6.635 kJ·mol^(-1).According to the principal component study,the relationship between the combustibility of the barks of the 13 tree species was as follows:Salix arbutifolia>Sorbus alnifolia>Populus suaveolens>Larix gmelinii>Quercus mongolica>Betula dahurica>Betula platyphylla>Pinus sylvestris var.mongolica>Populus davidiana>Alnus sibirica>Picea jezoensis var.microsperma>Pinus koraiensis>Picea koraiensis.The relationship between the combustibility of leaves was:Salix arbutifolia>Populus suaveolens>Sorbus alnifolia>Quercus mongolica>Betula dahurica>Populus davidiana>Betula platyphylla>Larix gmelinii>Alnus sibirica>Pinus sylvestris var.mongolica>Picea jezoensis var.microsperma>Pinus koraiensis>Picea koraiensis.The relationship of the flammability of 7 shrub species was in the order of Vaccinium vitis-idaea>Juniperus sabina var.davurica>Corylus heterophylla>Pinus pumila>Lespedeza bicolor>Rhododendron tomentosum>Vaccinium uliginosum.The flammability relationship of the shrubs was as follows:Lespedeza bicolor>Corylus heterophylla>Vaccinium uliginosum>Juniperus sabina var.davurica>Vaccinium vitis-idaea>Rhododendron tomentosum>Pinus pumila.【Conclusion】According to the relationship between the main trees and shrubs,Picea koraiensis(the tree species)and Vaccinium uliginosum(the shrub species)have the best fire resistance and shrubs are more flammable than trees.The results have provided a basis for the selection of the biological fire-resistant tree species in this area.