Abstract: By the method of emission factor (EF), this paper estimated the total carbon-containing gas emission from five main tree species in Daxing’an Mountains in forest fires from 1980 to 2005. The results showed that different tree species had different EF. Pinus sylvesstris var. mongolica and Populus davidiana had the maximum and minimum EF of CO₂, respectively. Larix gmeliniiand Betula platyphylla had the maximun EF of CO and C_xH_y, while B. platyphylla and L. gmelinii had the minimum EF of CO and C_xH_y. Based on the carbon storage in different organs and the total biomass of the tree, it was estimated that the total emission of CO₂, CO and C_xH_y from the five tree in the 25 years was 16.58 Tg, 1.61 Tg and 0.54 Tg, and the ontributions of L. gmelinii, P. sylvesstris var.mongolica, B. platyphylla, P. davidiana, and Quercus mongolica were 5.00 Tg, 0.63 Tg and 0.05 Tg, 0.225 Tg, 0.023 Tg and 0.003 Tg, 11.22 Tg, 0.83 Tg and 0.41 Tg, 0.0022 Tg, 0.004 Tg and 0.00034 Tg, and 3.12 Tg, 0.13 Tg and 0.062 Tg, respectively.

Key words: irrigation quota, orchard soil, moisture and salt redistribution, zero flux plane, water-soluble Na⁺ storage.