|
Abstract Taking Bauhinia blakeana, Elaeocarpus apiculatus, Mangifera indica, Alstonia scholaris, Bischofia javanica, Cinnamomum camphora, in Guangzhou City as test objects, a pot experiment was conducted to study the photosynthetic characteristics of these seedlings under effects of artificial simulation of the fumigation experiments with a gradient of 2.86mg/m3 of SO2 concentration (LSO2), 5.72mg/m3 of SO2 concentration (HSO2) and relatively clean area (CK). Results showed that：1) Compared with CK, the maximum net photosynthetic rate of six garden plants seedlings showed a downward trend with the increase of the concentration of SO2. Under two concentrations of SO2 stress, LSO2 and HSO2, the maximum net photosynthetic rate of Bauhinia blakeana, Elaeocarpus apiculatus, Mangifera indica, Alstonia scholaris, Bischofia javanica, Cinnamomum camphora decreased by 20.96% and 38.35%, 45.32% and 52.17%, 69.21% and 71.19%, 58.30% and 61.88%, 43.90% and 56.10%, 25.26% and 40.34%. 2) Light saturation point of Bauhinia blakeana, Mangifera indica, Alstonia scholaris, Bischofia javanica, Cinnamomum camphora ranged from 748-1016μmol/(m2·s), while their light compensation point ranged from 4.0 to 9.3μmol/(m2·s), and showed strong photophilic and shade-tolerant characteristics in a relatively clean area. Compared with CK, light saturation point of six kinds of garden plants occurred reduction to some extent. The largest decline of light saturation point was occurred in Mangifera indica, Alstonia scholaris, Bischofia javanica, while the smallest decline was in Cinnamomum camphora. 3) The effect of concentration of SO2 stress on light compensation point of six kinds of garden plants was not obvious. Under the stress of SO2 pollution, light adaptation range of six kinds of plants would be narrowing and poor. 4) Bauhinia blakeana and Cinnamomum camphora maintained the higher net photosynthetic rate and water use efficiency, and had higher adaptation ability to SO2 stress. The results would provide a reference for plants selection of severe acid contaminated areas such as thermal power plants, ceramic plants, steel mills and petrochemical plants.
|
