Effects of Auto-exhaust Pollution on Four Native Ornamental Trees: Stomatal and Photosynthetic Responses
交通尾气污染对城市绿化乡土树种的影响:气孔、光合生理的响应

The stomatal and photosynthetic responses of four native ornamental species, such as Elaeocarpus sylvestris, Syzygium hainanense, Ficus microcarpa var. pusillifolia, and Cinnamomum philippinense grown in heavy traffic Dongguan Road were studied. The results showed that stomatal morphology had no difference among four species, while stomatal density of 4 species at Dongguan Road increased significantly, in which Elaeocarpus sylvestris increased most. The contents of chlorophyll and carotenoid of 4 species in Dongguan Road had different adaptive changes, but the variations were inconsistent. Except for C. philippinense, the maxium net photosynthesis rate (Pmax) increased at Dongguan Road, but the changes of stomatal conductance and intercellular CO2 concentration were inconsistent. The responses to auto-exhaust pollution were different among 4 species. Therefore, the 4 species adapted to traffic exhaust pollution by changing morphological characters and physiological properties.