树种枝叶微观结构对树种燃烧性的影响研究

选择具有不同抗火能力的亚热带树种来研究树叶和树枝的微观组织结构与燃烧性的关系，分别测定木荷、茶树、油茶、苦槠、女贞、石楠、日本珊瑚树、枇杷、杉木和马尾松等10个树种叶片、叶脉和树枝的组织比，并利用锥形量热仪测定样品的阻火性。结果发现，树叶构造对燃烧性有影响，阔叶树种的树叶结构有利于水分的传输与蒸散，叶脉中木质部比重越大，越有利于水分的传输；海绵组织，栅栏组织与火发生指数之间存在显著的回归关系，茶树、木荷的海绵组织，栅栏组织比值高，抗火能力强。树枝的燃烧性与其结构密切相关。特别是树枝的抗火性与其导管所占比例正相关，木荷、日本珊瑚树的导管比重大，传输水分的能力强，抗火烧能力强。

STUDY ON THE INFLUENCE OF MICROSTRUCTURE OF TREE''''S TWIG AND LEAF ON COMBUSTIBILITY

The correlation between microstructures of leaf and branch and its combustibility was studied by using the tree species with different fire resistance ability. The issue ratios of leaf, branch and nervation of ten species were measured. The species included Camellia sinensis, Eriobotrya japonica, Camellia oleifera, Viburnum amabuki, Photinia serrulata, Castanopsis sclerophylla, Ligustrum lucidum, Schima superba, Pinus massoniana and Cunninghamia lanceolata . The Cone Calorimeter was used to determine the fire resistance of all samples. The results showed that the structure of leaves has affected on its combustibility. The structure of broadleaf was benefit on the transportation and loss of water. The higher the ratio of nervation, the more favorable would be the water transportation. The ratio of spongy tissue to palisade tissue had distinct regression correlation with the fire occurrence index. The ratio of spongy tissue to palisade tissue of Camellia sinensis and Schima superba was high and their fire resistance was high. The microstructures of leaf affected its combustibility. The ratio of vessel was positive correlation with the fire resistance of branch. Schima superba and Viburnum amabuki had a high weight of vessel, and they had fire resistance.