Emission of atmospheric pollutants during forest fire in boreal region of China.

Data on emission of atmospheric pollutants at local scale is essential for accurately modelling forest fire emission at regional scale. In this study, we quantified emission factor (EF) of gaseous pollutants (CO, CO2, NOx, hydrocarbons, organic carbon, and inorganic elements), fine particulate matter (PM2.5), water soluble inorganic ions, and non-methane hydrocarbons (NMHCs) from leaves, branches and barks of five dominant tree species in Chinese boreal region. Results demonstrate that the emission factors of different pollutants varied among tree species and fuel typology. The average total EF (leaves + branches + barks) of different species ranged from 922 ± 116 mg/g to 1383 ± 134 mg/g for CO2; 225 ± 109 mg/g to 277 ± 21 mg/g for CO; 0.6 ± 0.2 mg/g to 3 ± 0.7 mg/g for NOx; 32 ± 6 mg/g to 55 ± 7 mg/g for hydrocarbons; 3 ± 0.3 mg/g to 6 ± 0.7 mg/g for organic carbon; 0.6 ± 0.1 mg/g to 2 ± 0.1 mg/g for elemental carbon; and 4 ± 0.7 mg/g to 12 ± 1 mg/g for PM2.5. The total water soluble ions ranged from 5 ± 0.6 mg/kg to 12 ± 1.3 mg/g. For most of the pollutants, combustion of barks emitted more than that of leaves and branches. A total of 48 types of NMHCs (19 alkanes, 15 alkenes, and 14 aromatic compounds) were released during combustion of leaves, barks, and branches of tree species, with EF ranged from 982 mg/g to 1375 mg/g. Alkenes and i-butane, 1-butene, 1,3-butadiene, Isoprene, 4-Methyl-1-pentene, p-Xylene and benzene were the major ozone-forming compounds. Our results provide a comprehensive emission data by species and fuel typology that can be useful for modelling climate change, source apportionment and atmospheric photochemistry.

[Forest fire management in the United States]. / 美国林火管理概况及分析.

With the intensification of climate change and human activities, megafires frequently occur, with serious impacts on ecosystems, atmospheric environment, and human health. The United States has accumulated a large amount of practical experience in forest fire management. A comprehensive review of the framework of forest fire management in the United States can provide an inspiring reference for forest fire prevention in China. Starting from the process of historical evolution of forest fire policy, we systematically introduced the four stages of policy evolution and the characteristics of each stage in the US. Moreover, a comprehensive analysis of forest fire management situation in the US from four aspects was conducted, including the management of combustible fuels, administrative responsibility, fire suppression and forest fire management research support. We summarized relevant literature and proposed improvement strategies for future combustibles management, policy politics and fire fighting in the United States. Through the comprehensive analysis of forest fire management in the United States, we put forward some inspiring opinions on forest fire management in China to promote the establishment of a sound forest fire management system with Chinese characteristics.