江西大岗山常绿阔叶林优势种丝栗栲和苦槠栲不同叶龄叶片光合特性研究

Photosynthetic Characteristics of Dominant Species Castanopsis fargesii and Castanopsis sclerophylla in Different Leaf Ages in Dagangshan Mountain, Jiangxi Province

利用LI-6400便携式光合作用测量系统,研究了江西大岗山常绿阔叶林优势种丝栗栲和苦槠栲树冠中部不同叶龄叶片的光合生理特征。结果表明: ( 1 )丝栗栲叶片和苦槠栲叶片的净光合速率(Pn)、蒸腾速率(E)、气孔导度(Gs)、表观量子产量(AQY)、CO2 羧化效率(CCE)均表现为当年生叶片>1年生叶片>2年生叶片; (2)在相同叶龄条件下,丝栗栲叶片的净光合速率(Pn)、光补偿点(LCP)、表观量子产量(AQY)、气孔导度(Gs)、蒸腾速率(E)、CO2 羧化效率(CCE)、光能利用率(LUE)均显著高于苦槠栲叶片的相应值; (3)在相同叶龄条件下,丝栗栲叶片和苦槠栲叶片的水分利用率(WUE)没有显著差别; (4)2种植物叶片中的Chla/Chlb则表现为2年生叶片>1年生叶片>当年生叶片。

The LI-6400 portable photosynthetic system was used to study the Photosynthetic characteristics of the dominant species C. fargesii and C. sclerophylla in different leaf ages in Dagangshan Mountain in subtropical evergreen broadleaved forest. The results showed that: ① The increase of leaf age resulted in the significant decrease of net photosynthetic rate(Pn), the transpiration rate (E), stomatal conductance(Gs), apparent quantum yield(AQY), CO_2 carboxylation efficiency(CCE) irrespectively of different tree species. ② In the condition of the same leaf age, the net photosynthetic rate(Pn), the transpiration rate (E), stomatal conductance(Gs),apparent quantum yield(AQY),CO_2 carboxylation efficiency(CCE)and light use (efficiency) (LUE) of C. fargesii were significantly higher than those of C. sclerophylla. ③ In the conditions of same leaf age, the water use efficiency(WUE) of the two species had no difference. ④ The Chl a/Chl b value of the two species increased with the increase of leaf age.