The Responses of Gas Exchange of Bamboo(Fargesia denudata) Leaf on Elevated CO_2 Concentration and Light Intensity

To determine bamboo(Fargesia denudata) response on short-term elevated CO2 concentrations under 400,800,1 200 and 1 500 μmol·mol-1,LI 6400 Portable Photosynthesis System was used to examine the changes of the net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance (Gs) and vapor deficit at the leaf surface(Vpdl) of bamboo(Fargesia denudata) leaf with light intensity under different CO2 concentration.The results showed that with enhanced light intensity,Pn,Gs and Tr increased first and sustained at a high level then decreased,WUE(water use efficiency) increased first and sustained at a high and WUE increased first and then decreased,Gs and Tr decreased first and then increased and Vpdl increased.Under elevated CO2,the light saturation photosynthetic rate increased by 20%~61%,Gs and Tr decreased by 36%~57% and 30%~53% separately,WUE increased by 120%~215%,while Vpdl increased by 4%~11%.