3D models from terrestrial photogrammetry in the estimation of forest inventory variables

Abstract

The management of forest resources should be based on reliable measurements of individual standing trees. At the beginning, these measurements allow us to estimate equations and models, which in turn are used to be applied to similar individuals with the objective of estimate variables such as timber volume at plot or stand level. Traditionally, these measurements required the destruction of several standing trees. The present work intends the construction of three-dimensional models of standing trees by terrestrial photogrammetry. With this purpose, four plots were sampled in the MUP n°39 (Madrid) in each of which 5 representative trees were measured and photographed. For the measurement of standing trees, we used: tree caliper, Criterion RD1000 dendrometer and Vertex III hipsometer. The images were taken with a non-metric Canon IXUS 85 IS camera. Three-dimensional models were constructed from the images using VisualSFM software. Subsequently, measurements were made on these models using Meshlab software. The evaluation is performed by comparing the diameters measured on the 3D models with those obtained by other validated measurement methodology (using the Criterion RD1000 laser dendrometer). No significant differences were found between those measurements made with the Criterion and those made on the 3D models. Wood volume estimation of standing trees using photogrammetry is a sound alternative with potential for the next years.