Rapid measurement of trunk MOE on standing trees using RIGIDIMETER

International audience; Rigidimeter is a device developed in order to determine the modulus of elasticity (MOE) of standing trees. It was used on a hybrid Larch clonal test located at INRA, Orléans, France. Some of the examined trees were felled and remeasured. The goal of this study was to contribute to the validation of the Rigidimeter, as a fast non-destructive and reliable tool for rapid evaluation of MOE, an important mechanical property of wood. Two measurements in orthogonal directions improve the accuracy especially in the presence of reaction wood. We have showed that two measurements of diameter including bark with a precision of $\pm 1$ mm are sufficient to obtain a reliable second moment of area, which is an important parameter for the estimation of trunk MOE. Bark MOE is small compared to wood MOE, but bark thickness influences the measurement of tree diameter. A correction may be necessary to account for the presence of bark. We propose a method for estimating MOE of different trunk layers, such as bark and mature wood layer.