关键词: 干旱, 光合速率, 蒸腾速率, 气孔阻力

Abstract: Ammopiptanthus mongolicus (Maxim) is the only one of evergreen shrubs in desert region. Its biological feature and adaptation are important for studying the mechanism and diversity of desert plants. The result showed that under soil drought condition, the average and maximum of photosynthetical rate in leave of A. mongolicus is separately 2.14 μmol·m^-2·s^-1 and 3.5 μmol·m^-2·s^-1;And those of transpiration rate 7.03 mmol·m^-2·s^-1 and 10.5 mmol·m^-2·s^-1. However, when the soil is moist, the average and maximum of photosynthetical rate and transpiration ra te in leave of A. mongolicus are separately two and three times as those under drought condition. Through analysis of stomatal activity in leave, it was kno wn that the stomatal activity is closely related to leaf transpiration. The photosynthesis in leave is regulated by not only the stomatal activity but the bioch emical processes. This needs a further study in the future.

Key words: drought, photosynthesis, transpiration, stomatal resistance