Abstract:The function on reducing the heat island effect and contaminated gases on road surface was studied by means of multiCpoint synchronous observation method on horizontal scale of the landscape protection forest along an aerodrome road in Guangzhou. The results showed that the forest stand had a vertically 4-storey community structure by 2.39 of Shannon (H), and 0.76 of uniformity index and its canopy density attained to 0.68. Its vertical structure incarnates the multi-hierarchy collocation with the upper-storey of 12.6 m (Eucalyptus species), the middle storey of 6.3 m (hardwood species), the shrub storey of 3.2 m and herbage storey of 0.6 m. The shelterbelt stretches along the road with the width 30 m to 50 m. The results of a six-day observation in September 2006 showed that the daily mean concentration of SO2 and NO2 was 0.150 mg·m-3 and 0.083 mg·m-3 on road surface while that of in the forest belt with 20 m in width was reduced to lesser than 0.05 mg·m-3. At the same time, the air temperature of the road surface decreased by 2.0 ℃ and the air humidity of road surface increased 2.4 % by the forest belt with 20 m in width. In fine weather, the air temperature in the area 20 m and 30 m inside forest belt was 2.0 ℃ lower compared with that on the road surface from 13:00 to 15:00. Concurrently, the air humidity in the area 10 m to 30 m inside forest belt increased from 5.0% to 7.1%. The results of a observation of September 11-16, 2008 showed the SO2 concentration in the air was ≤0.05 mg·m-3 for 8.3-9.0 hours in the forest with a width of 20 m to 30 m, and the NO2 concentration in the air was ≤0.05 mg·m-3 and could last for 8.3 hours in the forest with a width of 30 m to 40 m. The shelter communities along the aerodrome road have marked ecological function on reducing the heat island effect and contaminated gases of road surface. Using trend surface regression method, the temporal and spatial distribution fitting equation of SO2 and NO2 concentrations from the road to forest obtained a good fitting result.