Spatio-Temporal Variation In Forage Production In A Key Resource Area In Succulent Karoo Rangeland, South Africa

Abstract

For herbivores to survive in arid rangelands, they largely depend on landscapes that act as grazing reserves during the dry seasons. In Richtersveld National Park, the dry season forage consists of browse from tree branches, litter and grass that grow along the Orange River. The aim of the study was to determine how browse production by tree species along the riparian zone (a key resource area), vary between the sites, with time and among the tree species, as well as the implication of a dry season key resource in management of rangelands. Sampling of tree species took place at three study sites along the riparian zone. In each site, temporal available standing biomass, browse and litter production by the seven dominant tree species were sampled. To calculate the total biomass production per tree canopy area, branch-count method was used up to a height of 1.5 m. Browse production differed between the tree species and between sampling periods but not between the sampling sites. Key resource area was found to play an important role in sustaining herbivores populations during the dry seasons as well as to reduce the negative effects associated with continuous grazing on the landscapes.