[Characteristics and affecting factors of sap flow density of Pinus tabuliformis and Hippophae rhamnoides in growing season in the hilly region of the Loess Plateau, China].

The dynamic changes of sap flow density (J) of Pinus tabuliformis and Hippophae rhamnoides in plantations from July to September in 2015 was monitored through thermal dissipation probe in the hilly region of the Loess Plateau. In addition, plant physiological characteristics were analyzed to determine the water use types of these two species. The results indicated that the daily changes of J of P.