Abstract: PROSPECT model is a well-known leaf optical model based on the radiative transfer processes within a leaf,which was used in this paper to simulate the leaf reflectance spectra of chlorophyll,water,and dry matter contents and mesophyll structure parameters,aimed to investigate the feasibility and precision of hyperspectral vegetation indices (VIs) in chlorophyll prediction,and their resistant performances against leaf water,dry matter,and mesophyll structure.A total of 5 widely-used VIs for predicting chlorophyll content,i.e.Chlorophyll Absorption Ratio Index (CARI),Triangular Vegetation Index (TVI),Photochemical Reflectance Index (PRI),Structured-Independent Pigment Index (SIPI),and Area of Band Normalization to the Center of Absorption Feature (ABNC),were considered.The simulation results showed that all the VIs except TVI were decreased with increasing chlorophyll content.Water content had little influence on VIs,because the major absorption features of leaf water were located at 1 300 nm and 1 900 nm which were not used in the VIs.Dry matter content had some influence on CARI and TVI,and mesophyll structure greatly affected the VIs except SIPI,because of the influence of mesophyll structure on the leaf reflectance spectra at both visible and near infrared regions.The use of simulated spectra in studying the affecting factors of chlorophyll VIs was a successful trial,which showed consistent results with measured rice leaf spectra.It was confirmed that the use of model-simulated spectra was theoretically based,simple,and generally applicable.

Key words: Rice field, Bio-controlling, Phytoplankton, Biodiversity