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利用Licor-6400便携式光合仪对新疆南疆绿洲外围人工营造的混交林中的胡杨和新疆杨的净光合速率(Pn)、蒸腾速率(Tr)、水分利用效率(WUE)、气孔导度(Gs)和胞间CO2浓度(Ci)等光合生理指标进行了测定。结果表明:1)胡杨的净光合速率日变化曲线呈“单峰型”曲线,新疆杨的净光合速率日变化曲线呈“双峰型”曲线,新疆杨的净光合速率峰值比胡杨的峰值高出约24.7%;2)两树种的蒸腾速率变化曲线均呈现“单峰型”曲线,新疆杨蒸腾速率的峰值比胡杨的峰值高出约54.6%;3)胡杨的平均水分利用效率为1.19±0.21μmolCO2.mmol-1H2O,新疆杨的平均水分利用效率为0.87±0.19μmolCO2.mmol-1H2O。胡杨比新疆杨有更高的水分利用效率;4)两树种的气孔导度日变化曲线都呈“单峰”型曲线,但是峰值出现的时间不同。新疆杨的气孔导度比胡杨的气孔导度要高;5)两树种的胞间CO2浓度日变化曲线均呈“单峰型”曲线变化。
The photosynthetic rate (Pn), transpiration rate (Tr), water use efficiency (WUE) and stomatal conductance (Gs) of P. euphratica and P. xylostella in artificial mixed forests planted in the periphery of Namjiang oasis in Xinjiang were measured by Licor-6400 portable photosynthesis system. ) And intercellular CO2 concentration (Ci) and other photosynthetic physiological indicators were measured. The results showed as follows: 1) The diurnal variation curve of net photosynthetic rate of Populus euphratica showed “unimodal ” curve. The diurnal variation curve of net photosynthetic rate of Populus xinjiang showed “bimodal ” curve. The net photosynthetic rate peak ratio The peak value of Populus euphratica was about 24.7% higher than that of Populus euphratica. (2) The transpiration rate curves of both species showed “single peak” curve, and the peak value of transpiration rate of Populus euphratica in Xinjiang was about 54.6% higher than that of Populus euphratica. 3) The water use efficiency was 1.19 ± 0.21μmolCO2.mmol-1H2O. The average water use efficiency of Xinjiang Populus was 0.87 ± 0.19μmolCO2.mmol-1H2O. Populus euphratica had higher water use efficiency than Xinjiang poplar. 4) The diurnal variation curves of stomatal conductance showed “unimodal” curves in both species, but the peak appeared at different times. The stomatal conductance of Xinjiang poplar was higher than stomatal conductance of Populus euphratica. 5) The diurnal variation curve of intercellular CO2 concentration in both species showed “unimodal” curve.