The extraction of canopy-understory vegetation-topography structure using helicopter-borne LIDAR measurement between a plantation and a broad-leaved forest

The relationship between stratification of canopy layers, understory vegetation and topography was investigated using helicopter-borne laser scanner data. The study plot was established ranging from an evergreen broad-leaved forest to a plantation of hinoki cypress (Chamaecyparis obtuse). LIDAR measurement was conducted with high density of footprints (23.4 points/m²) and both first pulse data and last pulse data were recorded. A local minimum filter was used to generate a digital elevation model (DEM). Adjoining spaces with 1 m wide along a certain direction in the stand were assumed and whole measurement data within every space were projected to a corresponding vertical plane to comprehend a canopy structure. It was found that through this processing that a series of vertical projective planes described stratification of canopy layers, gap structure, distribution of understory vegetation as well as topography.