Study on the Photosynthetic and Ecophysiological Characteristics of Endangered Pteridophytes Archangiopteris henryi

With CO2 photosynthetic analyzer,light compensation point and saturation light intensity for the pteridophyte Archangiopteris henryi grown in greenhouse were studied.By controlling light intensity,CO2 concentration,temperature and humidity in the leaf chamber,carboxylation efficiency and CO2 compensation point were analyzed and laboratory studies were conducted to investigate the relations between photosynthetic rate and light intensity,temperature and humidity.The results showed that the compensation irradiance was 5.3 μmol/(m2·s).Saturation light intensity was about 500 μmol/(m2·s).Archangiopteris henryi with obvious phenomenon of photoinhibition.Carboxylation efficiency of leaves was about 0.009 2 and CO2 compensation point was 51.8 μmol/mol.The photosynthetic rate was at the leaf temperature 10-20 ℃,raised with the temperature increased,when 20-35 ℃,reduced with the temperature decreased,the optimal temperature was from 16 to 31 ℃.When humidity went up from 20% to 80%,the rate of net photosynthesis increased.The optimum condition for the relative humidity was above 80%.