Influences of canopy architecture on relationships between various vegetation indices and LAI and FPAR: a computer simulation

Abstract

Simulation studies suggest that: (1) in most cases, VIs using off-nadir reflectances are more informative and useful than those based on nadir reflectances; (2) the optimal VI and sun/view geometries are usually different for inferring different parameters, depending on canopy architecture; (3) LAI can be practically estimated by VI only for homogeneous canopies while ground cover (GC) and Fpar can be inferred even for an inhomogeneous canopy; and (4) when optical properties of vegetation elements vary within a canopy, neither LAI/GC nor Fpar can be estimated by means of VI method with an acceptable accuracy. -from Authors