Fig. 3

TLS-based DBH estimation. a The “xy-range” approach computing a surrogate of DBH: x- and y-ranges were measured and averaged every 10 cm along the z axis of each stem, and the median was used as a surrogate of stem diameter. b The semi-automatic approach of DBH estimation for large-sized trees. Border points on the stem cross-section were manually selected and basal area BA was estimated, then the stem diameter D was computed from the formula BA = 𝜋D²/4. c Semi-automatic DBH estimation for insufficiently scanned stems. If possible, stem points were manually selected and a circle was fit to the points, resulting in an estimate of DBH