This dataset contains measurements of sap flow from the study area of the project Dendromass4Europe. Three poplar SRC stands were selected according to a gradient of groundwater accessibility: S5-N (higher groundwater level), S4-D (low groundwater level), and S2-F (fluctuating groundwater level). On each of the selected sites four trees were selected according to the tree diameter at breast height distribution.The aim of the study was to quantify the water use of clone "AF2" on sites with contrasting groundwater conditions. For the sap measurements a SFM1 sap device (Heat Ratio Method) was used at 20-minutes resolution in 2019 and 30-minutes resolution in 2021. In 2019 the sensors were installed in April and the measurements were conducted throughout the growing season until end of September. In 2021, measurements started in July and concluded in September. No measurements were conducted in growing season 2020.

Empty cells represent missing values