METER Group, Inc. 1 article published in JoVE Environment The Calibration and Use of Capacitance Sensors to Monitor Stem Water Content in Trees Ashley M. Matheny1, Steven R. Garrity2, Gil Bohrer3 1Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, 2METER Group, Inc., USA, 3Department of Civil, Environmental and Geodetic Engineering, Ohio State University The hydraulic capacitance of biomass is a key component of the vegetation water budget, which serves as a buffer against short and long-term drought stresses. Here, we present a protocol for the calibration and use of soil moisture capacitance sensors to monitor water content in the stems of large trees.