AIRBORNE RADIOMETRY AND A SHEEP GRAZING EXPERIMENT ON DUNE GRASSLAND

Radiometric data from an airborne scanner have been obtained for a gra zing experiment on dune grassland. The experiment consists of 32 fence d plots exposed to a range of sheep grazing intensities. Differential grazing intensities have changed the vegetation since the experiment w as set up, and there are positive correlations between sheep populatio n densities and both near-infrared and thermal-infrared radiance level s within each of the two different grassland communities (dune ridge a nd dune slack) of the experiment. These grazing-induced differences ar e of a similar magnitude to the radiometric differences between ridge and slack vegetation. The implications for using remote sensing to mon itor grazed vegetation are discussed.