Narrowband spectral indices for the estimation of chlorophyl along a precipitation gradient

Narrowband spectral indices have largely been used for the estimation of biochemical attributes of vegetation. However, most of the proposed indices were developed using a limited number of species and locations. In this study, a strong precipitation gradient in northern savannas of Australia was used to develop narrowband spectral indices for the estimation of leaf chlorophyll content and verify the spatial generality of the indices when applied to different species from different environmental conditions. Simple ratio indices (SRI) and normalized difference indices (NDI) were developed for samples taken from seven study sites along the transect. The results showed a limited transferability of the indices along the transect. Therefore, there is a need for more site-specific indices for large scale estimation of chlorophyll in the study area.