Characterizing the three-dimensional spatiotemporal variation of forest photosynthetically active radiation using terrestrial laser scanning data

•A method is proposed to estimate forest 3-D PAR distribution using TLS data.•The incident solar direct and diffuse PAR are treated separately in the method.•The effects of leaf orientations and LAIe on forest PAR are investigated.•When NPD≤20cm, lidar data are able to estimate the vertical PAR distribution.