Beyond the “climate versus grazing” impasse: using remote sensing to investigate the effects of grazing system choice on vegetation cover in the eastern Karoo

Abstract

Much research has been directed at determining the relative roles of climate and grazing in driving vegetation cover change in semi-arid ecosystems. Recent attempts seek to move beyond this debate as it has stagnated, or reached an "impasse". This study follows this pathway in investigating the effect of commercial stock grazing practices on vegetation cover in an eastern Karoo study site in South Africa. The study "corrects" a 14-year NDVI time-series for precipitation effects. Results suggest that some grazing strategies lead to consistently lower vegetation cover measures than do others, once rainfall is accounted for. Such findings provide a basis for recommendations for more sustainable grazing practices under conditions of variable precipitation.