Many investigations in the past decades have suggested that volatile organic compounds (VOCs) played an important role in tropospheric chemistry in the process of photochemical reaction with inorganic O_x, HO_x and NO_x. Most of researches about VOCs emitted from vegetation mainly focused on: (1) what are the role of VOCs emitted from vegetation to troposheric chemistry and their mechanism? (2) Why do many plants emit VOCs, and what is their eco-physiological significance? (3) What are main environmental fa...