[Transpiration water consumption of young Platycladus orientalis and Robinia pseudoacacia trees and their correction functions under different water supply].

Through artificial water control in the shed of rain-free, this paper studied the physiological water requirement patterns of 2-3 years old Platycladus orientalis and Robinia pseudoacacia trees during their growth period, and the relationships between their transpiration water consumption and soil water supply. The results showed that the transpiration water consumption of Robinia pseudoacacia was increased with increasing soil water supply within the range of 40%-100% of field water-holding capacity. Its maximum transpiration water consumption was at the early and accelerating growth stages, accounted for 80.5% of total annual water consumption. The transpiration water consumption of Robinia pseudoacacia was 5.13 times as much as that of Platycladus orientalis. Platycladus orientalis had a peak value of transpiration water consumption when the soil moisture content was 40%-100% of field water-holding capacity. Its transpiration water consumption was the maximum at accelerating growth stage, accounted for 46.27% of total annual water consumption, next at later growth stage, and relatively small at early growth stage. The correction functions of transpiration water consumption to soil water supply and the time-soil moisture functions of practical transpiration water consumption under insufficient water supply for two test species were put forward for the first time.