Non-destructive estimation of above-ground surface and near-surface biomass using 3D terrestrial remote sensing techniques

.Quantitative measurements of above-ground vegetationbiomass are vital to a range of ecological and naturalresource management applications. Remote-sensing techniques, such as terrestrial laser scanning (TLS) andimage-based point clouds, are potentially revolutionary techniques for measuring vegetation biomass and deriv-ing other related, structuralmetrics for these purposes.2.Surfacevegetationbiomass(upto25cm)inpasture,forest, and woodland environments is estimated from a3D point cloud derived from a small number of digitalimages. Volume is calculated, using the 3D cloud andregressed against dry weight to provide an estimateof biomass. Assessment of the method is made throughcomparison to 3D point clouds collected through TLS surveys.3.High correlation between destructively sampled biomass and vegetation volume derived from TLS andimage-based point clouds in the pasture (TLSr2¼075, image basedr2¼078),drygrassyforest(TLSr2¼073, image basedr2¼087) and lowland forest (TLSr2¼074, image basedr2¼063) environ-ments was found. Occlusion caused by standing vegetation in the woodland environment resulted in moder-ate correlation between TLS derived volume and biomass (r2¼050). The effects of surrounding vegetationon the image-based technique resulted in 3D point clouds being resolved for only 40% of the samples in thisenvironment.4.The results of this study demonstrate that image-based point cloud techniques are highly viable for the mea-surement of surface biomass. In contrast to TLS, volume and biomass data can be captured using low-cost equip-ment and relatively little expertise.