In order to investigate the effects of different irrigation rates on the photosynthetic characteristics of Salix psammophila,a man-made forest in Kubuqi Sandy Land was used as experimental material.The diurnal variation of photosynthesis and light response curve of Salix psammophila were measured by Li-6800 portable photosynthetic apparatus under four irrigation conditions.The results show that:The diurnal variations of net photosynthetic rate(Pn),transpiration rate(Tr),water use efficiency(WUE),and intercellular CO2 concentration(Ci)were significantly affected by different irrigation amounts.Except for WUE,which decreased with the increase of irrigation amount,the above factors all increased with the increase of irrigation amount.The photosynthetic capacity of Salix psammophila was significantly improved with sufficient irrigation amount.The light saturation point(LSP)of Salix psammophila under different irrigation treatments was greater than 1 200 µmol/(m2∙s),and the light compensation point(LCP)was between 35 and 175 µmol/(m2∙s).The maximum net photosynthetic rate(Pnmax)under different irrigation conditions was N1>N2>N3>CK.Dark reaction rate(Rd)N1>N3>CK>N2;Apparent quantum efficiency(AQY)N1>CK>N2>N3.The correlation analysis results showed that the most significant factors affecting the net photosynthetic rate were photosynthetically active radiation and intercellular CO2 concentration under different irrigation treatments.
Salix psammophiladifferent irrigation conditionsphotosynthetic characteristicsphotosynthetically active radiationenvironmental factors
NETL
NSTL
维普
万方数据
