Study On The Photosynthetic Characteristics Of Phyllostachys Eduli And Its Three Undergrowth Vegetation In Dagangshan In Jiangxi Province

In this paper, Pyhllostachys edulis and its three undergrowth vegetation: Castanopsis fargeii, Castanopsis sclerophylla and Woodwardia Japonica in Dagang Mountain forest ecosystem fixed research station was selected to test materials. By using portable photosynthetic measuring system LI-6400, studied the effect of different seasonal environmental factors on photosynthetic eco-physiological characteristics of Pyhllostachys edulis and its three undergrowth vegetation.The results showed: the net photosynthetic rate was gradually increased with the increase of CO₂ concentration,change tendencies of different months ware same. CO₂ compensation point (CCP) of Pyhllostachys edulis was 56.7～82.2μmol·mol^-1, apparent carbozylation efficiency (ACE) was 0.0166～0.0562. Response of Pn to PAR exist certain difference on different months, Pn was decreased with seasonal change. Photosynthetic traits of current Pyhllostachys edulis was higher than 3-year-old Pyhllostachys edulis. Current Pyhllostachys edulis has higher low light use efficiency and adapt to higher light intensity than 3-year-old Pyhllostachys edulis.CO₂ compensation point and apparent carboxylation efficiency of Castanopsis fargeii and Castanopsis sclerophylla ware same, CCP was 72.4～111.6μmol·mol^-1, ACE was 0.0111～0.0210, CCP of Woodwardia Japonica was 86.4～99.8μmol·mol^-1, ACE was 0.0093～0.0072. Light compensation point of Castanopsis fargeii and Castanopsis sclerophylla are same, Light saturation point of Castanopsis fargeii was higher than Castanopsis sclerophylla. Woodwardia Japonica adapt to Shade-tolerance.Short-term doubled CO₂ concentration increased the photosynthesis of Pyhllostachys edulis and undergrowth vegetation. Short-term doubled CO₂ concentration increased net photosynthetic rate, water use efficiency and light saturation point of leaves of Pyhllostachys edulis; light compensation point, stomatal conductance, transpiration rate and dark respiration rate of leaves of Pyhllostachys edulis was decreased. It is good for the growth of Pyhllostachys edulis.