Modelling herbivore grazing resources using hyperspectral remote sensing and GIS

We report on studies that successfully map the distribution of plant species as well as parameters indicative of the quality of forage for herbivores. We show that rangeland and wetland species and types may be discriminated and mapped using GIS and hyperspectral remote sensing. Using artificial medium, as well as field experiments, insect herbivore growth is positively related to nitrogen content, while significantly higher abundance of large herbivores occurs on nutrient enriched sites in southern Africa. Plant nitrogen concentration is shown to be significantly related to a shift in the red edge as well as key wavelength absorption points. Finally the reflectance of other leaf biochemicals associated with forage quality (P, K, Mg, Ca) are also discriminated and mapped.