Modeling spatiotemporal patterns of understory light intensity using airborne laser scanner (LiDAR)

This study described a spatiotemporally explicit 3D raytrace model to provide spatiotemporal patterns of understory light (light intensity in the forest floor and along the vertical gradient). The model was built based on voxels derived from LiDAR and field investigation data, geographical information (elevation and location), and solar position (azimuth and altitude angles). We calculated the distance (L, in meters) traveled by solar ray in the crowns based on the model, and then calibrated and verified the light attenuation function using L based on Beer’s law. L and the ratio of below canopy light intensity to above canopy light intensity showed obviously exponential relationship, with R2=0.94 and P