张今奇 周梅 赵鹏武 舒洋 李威 郭娇宇 管立娟

摘 要：可燃物是林火發生发展的物质基础条件，构成林火行为的主体。定量评价不同火烧程度火烧迹地死可燃物载量的影响对于理解火因子在生态系统中的作用具有重要意义。以恢复了10 a的内蒙古根河林区2009 年火烧迹地为研究区域，于2019 年6 月对研究区展开调查，沿海拔梯度设置9 块20 m×20 m标准样地，在每个标准样地中沿对角线设置 5 个小样方（1 m× 1 m），共 45 个。调查和测定环境因子、林分因子，计算在不同程度火烧迹地内死可燃物载量，采用逐步回归法建立死可燃物载量多元回归模型。结果表明：10 a恢复期对火烧迹地可燃物载量产生了一定的影响，重度和轻度火烧迹地中100 h 时滞死可燃物载量较多，分别为：（1.26±0.20） kg/m2、（1.50±0.10） kg/m2，受火灾后择伐影响，重度火烧迹地，烧死木、站杆大量减少，100 h 时滞死可燃物载量呈现轻度火烧大于重度火烧;建立死可燃物载量预测模型，1 h 死可燃物载量估测模型为Y1=1.794+0.166X1-0.004X2-0.278X3（R2=0.821）;100 h 时滞死可燃物载量估测模型为Y3=1.950-0.310X3+0.015X5-0.008X6+0.081X7（R2=0.710），影响因子中火烧程度（相关系数为-0.799）、平均树高（相关系数为0.689）、平均胸径（相关系数为0.474）3个因子相关性最高，拟合了100 h 时滞死可燃物载量的估测模型，经检验后发现100 h 时滞死可燃物载量的估测模型精度较为理想。

关键词：火烧程度;可燃物载量;预测模型;环境因子;林分因子;大兴安岭;郁闭度;树高

中图分类号：S762.2    文献标识码：A   文章编号：1006-8023（2021）03-0021-07

Abstract：Combustible material is the basic condition of forest fire occurrence and development and constitutes the main body of forest fire behavior. Quantitative evaluation of the effects of different fire degrees on the amount of dead fuel is of great significance for understanding the role of fire factors in the ecosystem. In June 2019， the study area was investigated in Genhe Forest District of Inner Mongolia， which was burned in 2009 and restored for 10 years. Nine 20 m × 20 m standard plots were set along the elevation gradient， and five small plots （1 m × 1 m） were set along the diagonal in each standard plot， a total of 45 plots were set. The environmental factors and stand factors were investigated and measured to calculate the dead fuel load in different degrees of fire. The multiple regression model of dead fuel load was established by stepwise regression method. The results showed that： the 10 a recovery period had a certain effect on the fuel load of the burned area. The 100 h time-delayed dead fuel load was higher in the heavy and mild burned areas， which were （1.26 ± 0.20） kg/m2 and （1.50 ± 0.10） kg/m2， respectively. Under the influence of postfire logging， dead burned wood and litter reduced greatly in heavy burned area， and the 100 h timedelayed dead fuel load of the mild burned area was higher than the heavy burned area. The prediction model of dead fuel load was established， the estimation model of 1 h dead fuel load was  （R2=0.821）; the estimation model of 100 h dead fuel load was  （R2=0.710）. Among them， three influencing factors： burning degree （correlation coefficient -0.799）， average tree height （correlation coefficient 0.689） and average diameter at breast height （correlation coefficient 0.474） had the highest correlation. The estimation model of 100 h timedelayed death fuel loads was fitted， and it was found that the accuracy of this model was ideal after testing.

Keywords：Burning degree; fuel load; prediction model; environmental factor; stand factor; Daxinganling; canopy closure; tree height

0 引言

森林火灾是世界性的林业重大灾害，被联合国粮农组织确认为世界八大自然灾害之一，对森林生态系统产生严重干扰，而中国是世界森林火灾最严重的国家之一[1]。……