Particulate emissions from fires in central Siberian Scots pine forests1

Abstract: Siberian boreal forest fires burn large areas annually, resulting in smoke that releases large amounts of par-ticulate emission into the atmosphere. We sampled aerosol emissions from experimental fires on three Scots pine (Pinus sylvestris L.) forest sites of central Siberia. Emissions from ground-based aerosol samples were 0.1–0.7 t/ha. This value represented 1%–7 % of the total biomass (10–30 t/ha) consumed during the experimental fires. We were able to classify the chemical composition of 77%–90 % of the mass of particulate fire emissions. Chemical analysis indi-cated that an average of 8%–17 % of the particulate composition was of mineral origin. Carbonaceous aerosols created because of incomplete combustion ranged from 50 % to 70 % of the total aerosol mass. The fraction of aerosols contain-ing elemental carbon (EC) (i.e., graphite, soot, and charcoal) was 7%–15%. As our samples were taken near the ground surface, these results represent freshly emitted fire aerosols that have not yet had time to react with atmospheric mois-ture or to undergo postfire chemical or physical–chemical changes. In a typical year, where 12 × 106 – 14 × 106 ha burn in Russia, we estimate that 3 × 106 – 10 × 106 t of particulate matter may be emitted into the atmosphere. Résumé: À chaque année, les incendies brûlent de vastes zones de forêt boréale en Sibérie. Ces incendies produisent de la fumée qui relâche dans l’atmosphère de grandes quantités de particules. Ils ont échantillonné les émissions d’aérosols provenant de feux expérimentaux dans trois forêts de pin sylvestre (Pinus sylvestris L.) du centre de la Sibérie. Sur la base d’échantillons d’aérosols prélevés au sol, les émissions atteignent 0,1–0,7 t/ha. Cette valeur représente 1 % – 7 % de l