Using 3d Scanning Technique for Estimating Forest Standing Volume

The use of 3D (three-dimensional) scanning in calculating tree's volume is discussed and suitable equations are fitted for estimating stand volume based on stem diameter at breast height (DBH) and height in the form of power and logarithmic functions. One hundred eighty-four individuals of Hopea odorata, Dipterocarpus alatus and Afzelia xylocarpa were scanned. Then, 3D images were used to calculate an individual tree's volume, based on sectioning the main stem and branches by assuming the cylinder of each section. The results indicated that 3D image calculations underestimated volume by 2.1-4.8% compared to the water displacement method by testing spiral branches of 4.3-15.7 cm diameter. The logarithmic function is the best-fitted model for each species and the combination of three species. A. alatus, H. odorata and combination of three species require both DBH and height, while A. xylocarpa needs only DBH in volume estimation. All four best fitted equations have Adjusted R-Squared > 0.88 and underestimate < 0.9% 3D volume. The smallest underestimate of 0.02% 3D volume belongs to the best-fitted equation for combination of three species, indicating the potentiality of using a combination of three species equation for estimating the volume of all species, especially in natural forests. It is concluded the suitability of using the 3D scanning technique for calculating individual tree's volume with high accuracy and establishing volume equations for multiple species applications, especially in the tropical forest.