The semiarid region of the Loess Plateau in China is characterized by its fragile ecosystems. Soil erosion and water shortage are major factors influencing the ecology and hydrology of vegetation in this area. For proper management of watershed ecosystems, quantification of water use by major vegetation types is needed. We used Granier-type thermal dissipation probes in a black locust (Robinia pseudoacacia) plantation, and up-scaled stand transpiration from individual measurements of stem sap flow. Stand transpiration water use during the growing seasons of 2008–2010 was estimated based on measured sap flux densities and sapwood areas. Seasonal and interannual variations were observed in stand-scale transpiration. Within a monthly time scale, water use by daily transpiration was correlated with daily solar radiation and daytime average vapor pressure deficit. The monthly changes in stand transpiration were mainly correlated with changes in leaf area index, and with mean daytime vapor pressure deficit, solar radiation and potential evapotranspiration at lower significance. A positive relationship between stand transpiration and soil moisture conditions was detected at an annual scale but not at a monthly scale. Precipitation did not show a clear correlation with stand transpiration at either seasonal or annual timescale. The results suggest that while the stand transpiration is controlled by multiple factors, those contributing to a significant difference vary with time-scales. Some factors (e.g. soil moisture) may only be detected upon long-term observations.