and Nitraria sphaerocarpa and Elaeagnus angustifolia are representative dominant shrubs in desert regions of China’s Heihe
River Basin. Therefore,weinvestigated the response of these shrubs to rainfall events by measuring sap flow in their branches and stems using stem flow gauges to confirm whether the thresholddelay model could be parameterized for these species and used to assess various response variables (including the rainfall threshold required to initiate a response).