Abstract: Based on the urban forest coverage data interpreted from QuickBird image (2006) and the CITYgreen model, the benefits of Shenyang urban forest types with different canopy closure in carbon fixation and pollutant removal were investigated by means of sampling strategy. The results showed that the total amount of carbon storage, annual carbon sequestration, annual air pollutant removal, and their corresponding values were 0.51 Tg, 6858.20 Mg·a^-1, 556.04 Mg·a^-1, 1.26×10⁸ Yuan, 1.72×10⁶ Yuan, and 0.22×10⁸ Yuan, respectively. Among the urban forest types in Shenyang City, ecological and public welfare forest (E) contributed most to the carbon fixation and air pollutant removal. The carbon density decreased in the order of S (subordinated forest) >L (landscape and relaxation forest)>P (production and management forest)>E>R (road forest), annual carbon sequestration was in the order of P>L>E>S>R, and annual air pollutant removal was in the order of P>L>S>E>R. The carbon density of different urban forest types was closely related to their structural complexity. For the forests with high canopy closure, both the annual carbon sequestration and the annual pollutant removal were high; while for those with lower canopy closure, these two characteristics were dependent on the structural complexity of the forests.

Key words: turnover, mine-ralization, organic matter, metabolic transformation, compound-specific isotope analysis of amino sugars