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以辽东山区7个主要造林树种为研究对象,测定了不同水分状态下光合速率、蒸腾速率、水分利用效率,对其日变化规律和相互关系进行研究,确定了水分利用效率的主要影响因子.结果表明:各树种光合速率和水分利用效率日变化规律均呈双峰型曲线,光合速率峰值分别出现在中午12:00和下午16:00,最终随着干旱程度的逐渐加大,水分利用效率逐渐降低;蒸腾速率日变化规律呈单峰型曲线,随着干旱程度的增加,峰值出现的时间由中午12:00提前到上午10:00.逐步回归分析表明,在水分充足状态下,水分利用效率变化的主要影响因子是胞间CO2浓度和气孔导度,与胞间CO2浓度呈极显著负相关,与气孔导度呈极显著正相关.
The main afforestation tree species in Liaodong mountainous area were taken as the research object, the photosynthetic rate, transpiration rate and water use efficiency under different water status were measured, and their daily variation and interrelationship were studied, and the main influencing factors of water use efficiency were determined. The results showed that the diurnal variation of photosynthetic rate and water use efficiency of all species showed a bimodal curve with the peak of photosynthesis occurring at 12:00 noon and 16:00 pm, respectively. Finally, as the degree of drought gradually increased, the water use efficiency gradually increased And the diurnal variation of transpiration rate showed a unimodal curve.With the increase of drought degree, the peak appeared time from 12:00 noon to 10:00 am.The stepwise regression analysis showed that the water use efficiency The main influencing factors of the changes are the intercellular CO2 concentration and stomatal conductance, which have extremely significant negative correlation with the intercellular CO2 concentration and extremely significant positive correlation with stomatal conductance.