Assessing accurate stem taper functions for poplar plantations

The value of wood and of different timber assortments can vary by a factor of ten thus, optimization of stems assortment is a key element in the wood products supply chain, particularly in plantations. ‘Taper function’ are commonly used in other countries to tackle this issue. In Italy this approach has not yet has not yet entered operational use. The functions are developed based on measures of stem diameters taken at different distances from the base. Such measurements are commonly taken felling the tree and using a tape meter and the tree caliper, clearly assuming some approximations. This research assesses the advantages, in terms of assortments evaluation, that can be obtained if the diameters at different heights are extracted adequately processing Terrestrial Laser Scanning (TLS) output. TLS data have been collected, in a poplar plantation, on 36 trees distributed on three stands with different plantation densities. Sensitivity of the models to stem eccentricity and plantation density will be tested, providing tools that will hopefully favour the diffusion of taper functions in operational environments.