关键词: 水曲柳, 根系, 叶片, 氮有效性, 生物量分配

Abstract: Forest fire prevention policy has been implemented over 50 years in the Great Xing′an Mountains in Northeast China, which lengthened the mean forest fire return interval and increased the forest fuel load. It’s needed to incorporate forest fuel management with the current forest fire prevention policy. In this study, ten fuel treatment scenarios were designed, five of which were the prescribed burnings (PB02, PB04, PBP6, PB08, PB10) and the other five were the prescribed burnings plus mechanical removals (PR02, PR04, PRP6, PR08, PR10), taking no treatment (NoTreat) as a contrast. The long-term (300 years) effects of the forest fuel treatment scenarios on the total burned area, the area burned by various intensity fires, and the dynamic characteristics of fire intensity were analyzed by using a spatially explicit forest landscape model LANDIS, and the results showed that prescribed burning could reduce the total burned area, but had less effect on reducing the area burned by high intensity fires because the decrement of total burned area became lesser with the increase of treatment size. However, prescribed burning plus mechanical removal could dramatically reduce the total burned area while changing the high intensity fire (classes 4 and 5) to low intensity fire (classes 1 and 2). It was suggested that forest fuel treatment should be implemented for a long period to effectively reduce the forest fire intensity and the likelihood of catastrophic fires.

Key words: Fraxinus mandshurica, Root, Leaf, N availability, Biomass allocation