根据野外火烧迹地调查,比较过火前后归一化植被指数的差异,计算2005—2007年大兴安岭林区各种可燃物类型的过火面积、火烧消耗的可燃物量,对森林火烧程度进行分级,并利用植物平均含碳率估算林火释放碳量.结果表明:2005—2007年大兴安岭林区总过火面积为436512.5 hm2,其中轻度、中度和重度火烧面积分别为207178.4、150159.2和79159.4 hm2.这些火烧消耗可燃物量为3.9×106 t,释放碳1.76×106 t,其中落叶松林、针阔混交林、阔叶林和草地燃烧释放的碳量分别为0.34×106、0.83×106、0.27×106和0.32×106 t.
Based on field investigation, the burned areas and consumed fuel loadings in Daxing’anling region caused by forest fires in 2005-2007 were estimated by comparing the normalized difference vegetation index (NDVI) before and after burning. The burned areas were classified with fire intensity, and the carbon emission from the fires was estimated by the fuel consumption and the average carbon content of plants. It was estimated that the total burned area was 436512.5 hm2, of which, the severe, moderate, and light burned areas occupied 207178.4, 150159.2, and 79159.4 hm2, respectively. The consumed fuel loadings were 3.9×106 t in total, and the emitted carbon was 1.76×106 t, with 0.34×106, 0.83×106, 0.27×106, and 0.32×106 t from larch (Larix gmelini) forest, conifer and broadleaves mixed forest, broad-leaved forest, and grassland, respectively.