Comparison of canopy transpiration between Pinus sylvestris var. mongolica and Pinus tabuliformis plantations in a semiarid sandy region of Northeast China

•Mongolian pine had higher canopy transpiration per unit leaf area than Chinese pine.•Transpiration was more sensitive to drought in Mongolian pine than in Chinese pine.•Mongolian pine had higher canopy conductance per unit leaf area than Chinese pine.•Reference canopy conductance decreased with increasing water stress for both species.•Decreased ability to control transpiration under drought conditions in Mongolian pine.