不同恢复时间火烧迹地地表死可燃物载量的变化

Change of Dead Fuel Load on the Surface of Burned Area in Different Recovery Times

为了探讨不同恢复时间火烧迹地地表死可燃物载量的特征、影响因子以及对森林火灾的影响。采用空间代替时间法,2019年7月,在根河林业局施业区内,选择2003年、2009年和2014年火烧迹地为研究对象,分别选择立地条件、火干扰强度及林分条件(林龄、密度、树种组成)近似的区域,设置6个10 m×10 m标准样地,并在未过火区设置6个对照样地,共设置24个样地,调查并记录样地信息,对所有样地的地表死可燃物取样。比较火烧迹地不同恢复时间的地表死可燃物载量差异,分析地表死可燃物载量与各影响因子的相关性,并使用逐步回归法建立多元回归模型。结果表明:恢复时间对火烧迹地的地表死可燃物的积累具有正面影响。总体上看,恢复时间越长,地表死可燃物载量越大;郁闭度、恢复时间和平均胸径与地表死可燃物载量相关性最高,相关系数分别为0.832、0.718、0.638;拟合了1 h时滞可燃物载量和地表死可燃物总载量与各影响因子的估测模型,模拟值与实测值差异不显著(P>0.05),模型估测精度具有可靠性。

We explored the characteristics of dead fuel load on the burned area at different recovery times,the influencing factors and the response mechanism to forest fires.Using the space instead of time method,in July 2019,in the construction area of Genhe Forestry Bureau,the burned sites in 2003,2009 and 2014 were selected as the research objects,whose site conditions,fire disturbance intensity and forest stand conditions are similar(Age,density,tree species composition),six 10 m×10 m standard sample plots and six contrast plots were set in the unfired area,for a total of 24 plots.We investigated and recorded sample plot information,and sampled dead fuel on the surface of all sample plots.Comparing the difference of the surface dead fuel load at different recovery time in the burned area,we analyzed the correlation between the surface dead fuel load and each influencing factor,and used the stepwise regression method to establish a multiple regression model.The recovery time has a positive effect on the accumulation of dead fuel on the surface of the burned area.On the whole,the longer the recovery time,the greater the surface dead fuelload;the stand canopy closure,recovery time and average diameter at breast height have the highest correlation with the surface dead fuel load,with correlation coefficients of 0.832,0.718 and 0.638,and the estimation fitting model of the 1-h time-lag fuel load and the total surface dead fuel load and various influence factors is with the ideal accuracy.