大岗山地区主要林型可燃物调查与林火行为

Forest Fuel Survey and Fire Behavior in Main Forests in Dagangshan

以江西大岗山地区11个主要植被类型为研究对象,调查立地因子和林分因子。测量每个样方内的枯落物、鲜草和枯草、及1、10、100和1 000 h的地表枯枝载量,并采集样品。在林火实验室测定可燃物热值、抽提物、灰分和粗纤维质量分数,并进行相关分析,计算林火蔓延速率、火强度和火焰长度。研究得出,天然林地表可燃物载量普遍大于人工林;天然林火行为指标大于人工林,针叶林火行为指标大于阔叶林,纯林火行为指标大于混交林,落叶阔叶林火行为指标大于常绿阔叶林。通过比较各植被类型蔓延速度、火强度和火焰长度这3项林火行为指标,对林火行为可能造成的森林危害做出评价,并提出森林防火决策。

Taking 11 major vegetation types in Jiangxi Dagangshan area as the targets,the site factors and stand factors were surveyed.litter,grass and hay,and 1,10,100,1 000 h of surface dry twig load were measured in every quadrat,and samples were collected.The calorific value,extract,ash and crude fiber mass fraction of combustible materials were measured in the forest fire laboratory,and through correlation analysis,the fire spread rate,fire intensity and flame length were calculated.The study results showed,the forest surface fuel load in the natural forest was generally greater than in the plantation;the forest fire behavior indicators in the natural forest were greater than in the plantation,that in the coniferous forest were greater than that in the broad-leaved forest,that in the pure forest were greater than that in the mixed forest,that in the deciduous broadleaf forest were greater than that in the evergreen broad-leaved forest.By comparing the spread rate,fire intensity and flame length of these three forest fire behavioral indicators in each vegetation type,the loss and harm caused by forest fire behavior were assessed,and some countermeasures against forest fire are proposed.