A study of emissions and marker gases from smouldering combustion in Larix gmelinii plantations of the Daxing’an Mountains

Underground fires are characterized by smouldering combustion with a slow rate of spread rate and without flames. Although smouldering combustion releases large amounts of gaseous pollutants, it is difficult to discover by today’s forest fire monitoring technologies. Carbon monoxide (CO), nitrogen oxides (NOx) and sulfur dioxide (SO2) were identified as high concentration marker gases of smouldering combustion-easily-be monitored. According to a two-way ANOVA, combustion time had a significant impact on CO and NOx emissions; smoldering -depth also had a significant impact on NOx emissions but not on CO emissions. Gas emission equations were established by multiple linear regression, Cco = 156.989 − 16.626 t and CNOx = 3.637 − 0.252 t − 0.039 h.