Abstract: Assessing spatial distribution of air quality purification functions of forest ecosystems can provide reference for ecosystem management. From aspects of negative iron supply, absorption of SO₂, absorption of fluorine, absorption of NO_X, dust retention, PM₁₀ retention and PM_2.5 retention, we examined the spatial pattern of air quality purification functions of the forest ecosystems in Helanshan Nature Reserve along the horizontal and vertical gradients. Results showed that air quality purification function of the forest ecosystems in the reserve was substantial, with negative iron supply being 1.426×10²³·a^-1, PM₁₀ retention and PM_2.5 retention being 361.27 and 77.44 t·a^-1, respectively. In the horizontal direction, the substance amount and capital value of the forest ecosystems was the highest in the central of the reserve, followed by the south, and least in the north. Both substance amount and capital value in the five management stations of the reserve were in order of Dashuigou > Maliankou > Suyukou > Shizuishan > Hongguozi. On the vertical gradient, the substance amount and capital value of the forest ecosystems were higher at the altitude of 2400-3000 m than at 3000-3500 and 1800-2400 m, and were higher on the shady slope than on the sunny slope. With respect to forest types, the air quality purification function of shrubs and spruce forests was the largest.

Key words: Peanut, Balance fertilization, Nutrient absorption, Potash fertilizer effect