A transportable magnetic resonance imaging system for in situ measurements of living trees: The Tree Hugger

► A permanent 1 MHz 1H magnet for in situ NMR/MRI of living trees is presented. ► The magnet has an open access space of 210 mm diameter and weighs 55 kg. ► Images have been obtained of a Bird Cherry tree throughout a growing season. ► NMR data correlates with solar radiation, soil moisture and relative humidity. ► NMR data also correlates with tree sap flow and grain-angle.