Tropical tree size-frequency distributions from airborne lidar

Tropical rainforest canopies, where stems and crowns reside, are hotspots of biological diversity, mediate the global biochemical processes and are the interface between organic nature and the atmosphere. Ecosystem functions such as growth, competition and mortality, depend on the spatial arrangement of tree crowns that varies significantly across forest types and disturbance gradients. The exact nature and function of tropical tree canopies are not well known. Field inventories often focus on measuring the horizontal component of the canopy (tree diameter and species identification) and rarely measure tree height or crown size. Remote sensing airborne lidar (light detection and ranging) is considered a complementary method to circumvent the difficulty of field techniques in measuring forest canopies, with recognized ability to estimate canopy height and vegetation vertical profiles. A recent lidar-based method (adaptive mean shift, AMS3D) shown improved capabilities to deal with the co...