Estimation of coniferous standing tree volume using airborne LiDAR and passive optical remote sensing

Abstract

In this study, we confirmed the utility of airborne LiDAR and passive optical remote sensing techniques for estimating the standing tree volume of two coniferous trees, 28 Japanese red pine and 13 Japanese cedar trees respectively. Airborne 3-D LiDAR data and aerial photographs provided the respective height and crown area for each of the selected trees. Subsequently, we examined the relationships between 1) LiDAR-derived tree height and Field-based stem volume and 2) the crown area obtained from aerial photograph and the field-based stem volume. In addition, we made a multiplicative equation composed of both tree height and crown area to predict the stem volume, and examined its accuracy by comparing the predicted standing tree volume with the field-based volume. Consequently, stronger correlations were observed between the LiDAR-derived tree height and stem volume in both species, while those between the crown area obtained from aerial photographs and the stem volume were weaker in both species. At the multiplicative equation, R2 and SE of the stem volume were 0.90 and 0.046 m3 for the Japanese red pine, and 0.83 and 0.025 m3 for the Japanese cedar respectively, which represented a better result than using tree height or crown area alone, especially for the Japanese cedar. This shows the effectiveness of the combination of LiDAR and passive optical sensors in estimating the standing tree volume.