Data from: 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 complexity of tropical forest and to provide spatial explicit measurements of crown morphology and packing by modeling individual trees.

Here, we report tree-level forest inventory (field and LiDAR) over nine 1 ha forest plots in the La Selva Biological Station, Costa Rica. The field inventory includes stem location (tree height > 10m), tree diameter, tree height and wood density. Crown radii measurements for a tree subsample (n=285) were used to derive local tree allometry. The lidar forest inventory includes the point clouds measurements over the 1 ha plots with an additional attribute to cluster the individual points into tree crowns. The lidar tree crowns were modeled to estimate tree location, tree height, crown depth, crown area, crown volume and crown surface. Additionally, we provide tree-level LiDAR forest inventory for 45360 plots (1 ha) distributed over old-growth, selectively-logged, secondary and swamp forests. The field inventories have been compared and show good agreement in terms of stem number density, size-frequency distributions (stem diameter, tree height), basal area and aboveground biomass.