Photosynthetic physio-response of urban Quercus mongolica leaves to surface elevated ozone concentration

Surface layer O3 concentration increases has become one of hot issues of the environment scientific research.This paper simulated the photosynthetic physio-response of Quercus mongolica,a main greening tree species in Shenyang urban forest,under elevated ozone concentration.With the use of open-top chamber device,the photosynthetic physio-response of elevated ozone concentration on urban Quercus mongolica leaves for a growing season was studied.The results showed that with the high concentration of ozone fumigation,net photosynthetic rate,photosynthetic pigment,photosynthate,photosynthetic electron transport and photophosphorylation were as the trend of increasing firstly then decreasing lastly and relative electrical conductivity increased compared with the control.It can be seen that net photosynthetic rate,carotenoid,ATPase and starch of treated leaves were lower than that of the control,which the differences reached best significant level(p0.01)and chlorophyll reached significant difference(p0.05)in the 30d.While the decrease of net photosynthetic rate and reached significant level(p0.05), but the decrease of chlorophyll and Mg2+-ATPase reached best significant level(p0.01)compared with the control in the 90d.The photosynthetic ability of Quercus mongolica leaves has declined under the elevated ozone concentration.