Terrestrial Laser Scanning for Plot-Scale Forest Measurement

Abstract

Plot-scale measurements have been the foundation for forest surveys and reporting for over 200 years. Through recent integration with airborne and satellite remote sensing, manual measurements of vegetation structure at the plot scale are now the basis for landscape, continental and international mapping of our forest resources. The use of terrestrial laser scanning (TLS) for plot-scale measurement was first demonstrated over a decade ago, with the intimation that these instruments could replace manual measurement methods. This has not yet been the case, despite the unparalleled structural information that TLS can capture. For TLS to reach its full potential, these instruments cannot be viewed as a logical progression of existing plot-based measurement. TLS must be viewed as a disruptive technology that requires a rethink of vegetation surveys and their application across a wide range of disciplines. We review the development of TLS as a plotscale measurement tool, including the evolution of both instrument hardware and key data processing methodologies. We highlight two broad data modelling approaches of gap probability and geometrical modelling and the basic theory that underpins these. Finally, we discuss the future prospects for increasing the utilisation of TLS for plot-scale forest assessment and forest monitoring.

Quantifying micro-environmental variation in tropical rainforest understory at landscape scale by combining airborne LiDAR scanning and a sensor network

“…Low sampling of the understory due to insufficient aerial LiDAR penetration can be overcome by terrestrial LiDAR, which allows a much denser sampling pattern. It may also ultimately provide robust leaf area index estimates as it has the potential to separate leaf from non-leaf material (Raumonen et al 2013;Calders et al 2015;Newnham et al 2015) and to provide a more accurate description of the spatial arrangement of the foliage (clumping and orientation). Fig.…”

Terrestrial Laser Scanning for Forest Inventories—Tree Diameter Distribution and Scanner Location Impact on Occlusion

“…The combination of multiple scanner positions reduces the occlusion in a stand substantially [17,34,42,43]. Based on scanner location patterns found in the literature, we simulated 25 single scanning positions on each sample plot (n = 536) (see Figure 4) and combined them to form a total of 40 scanning location patterns (see Figures A2 and A3 in the Appendix A).…”

“…For these objects, only multiple TLS measurements can improve the coverage, albeit in a linear fashion. Newnham et al [42] identify two different categories of data retrieval approaches from TLS generated point clouds: gap probability and geometrical modelling. While the former approach samples the forest scene to provide a complement of all vegetation components, the latter uses the discrete point clouds to derive geometrical properties of the scanned object, e.g., by quantitative structure modelling (QSM) [44,45].…”

Precise Measurement of Stem Diameter by Simulating the Path of Diameter Tape from Terrestrial Laser Scanning Data

“…Compared with airborne laser scanning and field measurements, TLS can obtain accurate understory information, including a digital record of the three-dimensional structure of forests [3]. Many studies have demonstrated the high potential of TLS in forest inventory, including tree locations [1,[4][5][6], heights [2,3,7], diameters [2,3,6,[8][9][10][11][12][13][14][15], volumes [16][17][18], biomass [17,[19][20][21][22][23] and others forestry parameters [24][25][26][27]. In addition, the influence of scanner parameters on forestry parameter derivation has been studied [18,28].…”