【摘要】 以不同pH值的模拟酸雨对樟树进行处理,研究酸雨对樟树光合作用日变化的影响.结果表明:(1)模拟酸雨处理的樟树净光合速率日变化均呈不对称的双峰形,峰值分别出现在10:00、14:00,12:00表现“光合午休.”(2)模拟酸雨处理的樟树“午休”表现更加明显,“午休”时净光合速率下降幅度增大,模拟酸雨降低了其净光合速率的日变幅.(3)pH 3.0、pH 4.0的模拟酸雨增大了樟树日均净光合速率.(4)3种酸雨均降低了樟树气孔导度最小值,而pH 3.0、pH 4.0的酸液增大了其气孔导度最大值、日变幅.(5)3种酸液均增高了樟树气孔限制值的最小值,降低了其气孔限制值的最大值和日变幅.(6)3种模拟酸雨均增大了樟树胞间CO2浓度最小值,而pH 4.0酸雨增大了其胞间CO2浓度最大值和日变幅.更多还原

【Abstract】 The effects of simulated acid rain on the diurnal changes of Cinnamomum camphora photosynthesis were studied by treating it with simulated acid rain solution of different pH values.The results are showed as follows:（1） There is a non-symmetry double peak shape from the diurnal changes of the photosynthesis rate of simulated acid rain treatments;the first peak appears at 10:00,the second at 14:00 and there is a photosynthetic depression at 12:00;（2） The photosynthetic depression of Cinnamomum camphora treated with simulated acid rain is significant.During the photosynthetic depression,the range of net photosynthesis rate declines more than those without being treated; meanwhile simulated acid rain also reduces the range of diurnal change on net photosynthesis rate;（3） Simulated acid rain of pH3.0 and pH4.0 increases respectively the mean net photosynthetic rate of Cinnamomum camphora;（4） Three kinds of simulated acid rain lower the least values of the stomatal conductance of Cinnamomum camphora while the acid rain of pH3.0 and pH4.0 increases the largest valve and the diurnal change of stomatal conductance;（5） The three kinds of acid rain also increase the least value of the stomatal limitation of Cinnamomum camphora and decrease the largest value and the diurnal mean values of stomatal limitation;and（6） the three kinds of simulated acid rain increase the least value of intercellular CO₂ concentration of Cinnamomum camphora while that of pH4.0 increases the largest value and the diurnal change range of intercellular CO₂ concentration.更多还原