长白落叶松净光合速率和呼吸速率的日变化及时空影响

Diurnal Variations of Net PhotosyntheticRate and Respiration Rate in Larix olgensisHenry and Effect of Season and Position

不同季节测定了长白落叶松树冠３个层次，４个方向１２个部位的净光合速率和呼吸速率的日变化，得到双峰曲线型、单峰曲线型和平坦型３种日变化模式。结果受测定日的气象条件、测定叶在树冠中的位置和测定季节及它们的相互作用的综合影响。长白落叶松净光合速率和呼吸速率的平坦型日变化是由内因决定的，单峰及双锋曲线型日变化是由外因和内因共同决定的。净光合速率与呼吸速率呈正相关，二者的低谷与峰值同时出现。呈双峰曲线型日变化时，两个峰值的大小不同，下午峰值明显高于上午峰值，这与前人结果不同，午休现象与高温对有关酶系统的抑制及水分亏缺有关。

Diurnal variations of net photosynthetic rate and respiration rate at 12 positions (3 levels ×4 dirctions) of crown ln Larix olgensis Henry were measured at different season Three kinds of diurnal variations, ie bipeak pattern, monopeak pattern and smooth pattern, were obtained The results were affected comprehensively by the weather condition, season of experiment and the position of the measured conifer in crown, and their interaction one another The smooth pattern diurnal variations of net photosynthetic rate and respiration rate were determined by internal cause; their diurnal variations of bipeak and monopeak pattern were determined by the action of internal and external cause Net photosynthetic rate was correlated with respiration rate positively Their lowest and peak values appeared at the same time The values of the two peak were different The peak appeared afternoon was higher obviously than that at forenoon, which was different with the results of other researcher The ″noon nap″ phenomenon was related with the restrain of high temperature to related enzyme system and water deficit