中文摘要：

本文基于干沉降模型对北京市平原区造林削减PM2.5效应进行了评估。结果表明：2012年所造森林PM2.5年削减量可达451 t,其中,阔叶林削减量占57%;不同季节的削减量有较大差别,春季的削减量占全年的50%;造林工程可使造林区PM2.5浓度平均下降0.57μg·m-3,完成《北京市2013—2017年清洁空气行动计划》目标的2%;平原区造林对于减缓和控制PM2.5、改善城市大气环境质量具有一定作用,在目前治理PM2.5有效方法不多的状况下,应当继续开展平原区造林。

英文摘要：

Based on a dry deposition model, we evaluated the PM2.5 particles reduction effect of plain afforestation project in Beijing. The results showed that 451 t PM2.5 particles had been re- duced by the trees planted in Beijing plain areas in 2012. Among these trees, broadleaf forest contributed 57% of the total reduction. The reduction effect was variable in different seasons, with 50% of reduction happening in spring. The plain afforestation project had made the annual average PMz5 concentration in the afforestation area decreased by 0. 57μg· m-3 that has achieved 2% of the target from ＂Beijing Clean Air Action Plan （2013-2017）＂. The plain affor- estation has played an important role in the urban pollution management. Considering that there is no effective way to control the PM2.5 pollution, we recommend continuing carrying out the plain afforestation project in appropriate circumstances.