Exploring spectral discrimination of grass species in African rangelands.
The spectral reflectance from eight species (Themeda triandra, Hyperthelia dissoluta, Brachiaria brizantha, Panicum maximum, Echinochloa haploclada, Setaria sphacelata, Sporobolus pyramidalis and Dichanthium insculptum [Bothriochloa inscultpa]) of rangeland grasses in the Masai Mara Nature Reserve, Kenya, was measured using a laboratory-based spectrometer. There were statistically significant differences in the spectral reflectance between species - a result which is encouraging for future work on identifying, classifying, mapping and monitoring rangeland ecosystems from hyperspectral imagery. To date, hyperspectral imagery has been available only through airborne scanners, but the European Space Agency and the United States' National Aeronautics and Space Administration (NASA) both plan satellite missions. The second part of this paper describes the acquisition and analysis of hyperspectral data (CASI) coincident with ground plots. In these plots, the mix of grass species varied from pure (monospecific) patches through to mixes of four to five different species. Evidence is presented indicating that some species may be identified on the image, based on the laboratory-obtained spectra.