Figure 4

Plots of the hourly changes in sap flow (SF), photosynthetically active radiation (PAR), vapor-pressure deficit (VPD), air temperature (T_a), and wind speed (u_s) for Amorpha fruticosa seedlings on three days with typical and similar meteorological conditions but different soil conditions (REW_0–40 cm represents the relative extractable water in the top 40 cm of the soil; EC represents the electrical conductivity). The data are for (a) 17 June 2017, a typical day with soil water stress and high salinity (REW_0–40 cm = 0.33, EC_0–40 cm = 4.33 mS·cm⁻¹, EC_40–80 cm = 3.15 mS·cm⁻¹); (b) 22 June 2017, a typical day with no soil water stress and high salinity (REW_0–40 cm = 0.85, EC_0–40 cm = 3.32 mS·cm⁻¹, EC_40–80 cm = 3.12 mS·cm⁻¹); and (c) 19 July 2017, a typical day with no soil water stress and low salinity (REW_0–40 cm = 0.84, EC = 2.62 mS·cm⁻¹, EC_40–80 cm = 2.25 mS·cm⁻¹).