Use of multi-temporal UAV-derived imagery for estimating individual tree growth in Pinus pinea stands

摘要: High spatial resolution imagery provided by unmanned aerial vehicles (UAVs) can yield accurate and efficient estimation of tree dimensions canopy structural variables at the local scale. We flew a low-cost, lightweight UAV over an experimental Pinus pinea L. plantation (290 trees distributed 16 ha with different fertirrigation treatments) to determine positions estimate individual height (h), diameter (d), biomass (wa), as well changes in these between 2015 2017. used Structure from Motion (SfM) 3D point cloud filtering techniques generate model object-based image analysis delineate crowns (ITC). ITC results were validated using field measurements subsample 50 trees. Comparison SfM-derived field-measured h yielded R2 value 0.96. Regressions explanatory described 79% 86–87% variability d wa, respectively. The growth estimates across entire study area for period 2015–2017 0.45 m ± 0.12 198.7 93.9 kg, Significant differences (t-test) observed end period. findings indicate that proposed method could be derive individual-tree detect spatio-temporal changes, highlighting potential role UAV-derived forest management tool.