Study On Forest Fuel Of Daxing' An Mountains In Northeast China

In this paper, the author discussed the history and the main content of forest fuel study, and reviewed the research status quo of forest fuel of home and abroad. The main content of forest fuel are such as: the physicochemical property of the fuel, the distribution and disposition of the fuel, the division of the fuel types and the research and development of the fuel models. The author studied the forest fuel of Daxing'an mountains from several aspects and main findings of the study are as follows:1. The fuel models of the surface fuel of all types were established by introducing the standing forest factors such as forest age, canopy density, mean height and diameter breast height. The fitting effect of the models is satisfactory, so it is feasible that the surface fuel are estimated by using the standing forest factors.2. The fire resistant ability and component about 16 tree species in Daxing'an Mountains have been determined in laboratory. The distinctions about the Properties between the tree species and between leaves, twigs and bark have been analyzed. The results indicate that wind dried moisture content correlates with construction of tree species. Different tree species have different ability on combining water; Absolutely dried moisture content correlates with inner construction of leaves, twigs and bark, and correlates little with construction of tree species; As long as it is woody plant, the difference of ignition point is minor; Ash and extractive correlate with construction of tree species, and correlate little with inner construction of leaves, twigs and bark. This induces that the difference of heat of combustion between the tree species is terribly noted. By multiple comparison of means of absolutely dried moisture content between leaves, twigs and bark, it was gained that bark is inflammable, leaves and twigs aren't inflammable in contrast from absolutely dried moisture content. By factor analysis of influencing heat of combustion, it was gained that component of tree species has an obvious influence on its fire resistant ability. Content of extractive has positive correlation with heat of combustion; content of ash has negative correlation with heat of combustion. Content of ash is high, then noncombustible matter is plentiful, so heat of combustion is small.3. Moisture content, ignition point, ash, heat of combustion and extractive of leaves, twigs and bark have been analyzed about 16 species of arbor tree and shrub by applying factor analysis and specialist marking. Ordering of fire resistant leaves, twigs, bark and tree species has been gained. The tree species of the best fire resistant leaves are: Larix gmelini, Prunus padus L., Betula nigra L; The tree species of the worst fire resistant leaves are: Pinus sylvestris L.var. mongolica Litv., Ledum palustre var, dilatatum Wahlanb., Vaccinium vitis-idaea L. The tree species of the best fire resistant bark are: Salix koreensis Anderss., Cornus alba L, Betula nigra L; The tree species of the worst fire resistant bark are: Pinus sylvestris L.var. mongolica Litv., Larix gmelini, Ledum palustre var. dilatatum Wahlanb.. The tree species of the best fire resistant twigs are: Populus davidiana Dode, Populus suaveolens, Salix koreensis Anderss.; The tree species of the worst fire resistant twigs are: Ledum palustre var. dilatatum Wahlanb., Pinus sylvestris L.var. mongolica Litv., Betulaplatyphylla Suk.. By integrating the fire resistant ability of leaves, twigs and bark, The tree species of the best fire resistant ability are: Prunuspadus L, Betula nigra L, Larix gmelini; The tree species of the worst fire resistant ability are: Ledum palustre var. dilatatum Wahlanb., Pinus sylvestris L.var.mongolica Litv, Rhododendron simsii Planch..4. Heat per unit area and rate of spread of each type change with moisture content of fuel changing. Heat per unit area makes certain if moisture series are immovable, but rate of spread changes. Rate of spread increases with wind speed increasing in a general way. But rate of spread actual...