The use of terrestrial LiDAR technology in forest science: application fields, benefits and challenges

Introduction The use of terrestrial LiDAR (light detection and ranging) scanners in forest environments is being studied extensively at present due to the high potential of this technology to acquire three-dimensional data on standing trees rapidly and accurately. This article aims to establish the state-of-the-art in this emerging area. Objectives Terrestrial LiDAR has been applied to forest inventory measurements (plot cartography, species recognition, diameter at breast height, tree height, stem density, basal area and plot-level wood volume estimates) and canopy characterisation (virtual projections, gap fraction and three-dimensional foliage distribution). These techniques have been extended to stand value and wood quality assessment. Terrestrial LiDAR also provides new support for ecological applications such as the assessment of the physical properties of leaves, transpiration processes and microhabitat diversity. Results Since 2003, both the capabilities of the devices and data processing technology have improved significantly, with encouraging results. Nevertheless, measurement patterns and device specifications must be selected carefully according to the objectives of the study. Moreover, automated and reliable programmes are still required to process data to make these methodologies applicable specifically to the forest sciences and to fill the gap between time-consuming manual methods and wide-scale remote sensing such as airborne LiDAR scanning.