Paper 1: Vegetation, habitats and browse availability in the Waterval section, Augrabies Falls National Park – place of scarcity and diversity. Kenneth G. Buk Zoological Museum, University of Copenhagen, 1 Universitetsparken, 2100, Denmark.
[email protected] Abstract Factors potentially affecting habitat suitability for large browsers were quantified in 7530 ha of mountainous desert in Waterval, Augrabies Falls National Park, western South Africa. The vegetation was classified and mapped according to plant species associations. In each vegetation community vertical cover, shade, substrate composition as well as canopy volume of each browse species were measured. Furthermore, water availability and steepness of slopes were mapped. The varied topography and soils of Waterval result in a high diversity of browse (D=19.0, H’(ln)=3.45) divided into ten vegetation communities including seven shrublands (61.7 % by area), two woodlands (37.1 %) and a riverine forest (1.1 %). The average browse availability 0-200 cm above ground is 1 096 ±90 m 3/ha, ranging from 597 to 14 446 m 3/ha among vegetation communities. The browse includes Acacia mellifera (15.0 %), Schotia afra (12.7 %), Monechma spartioides (4.5 %), Acacia karroo (4.2 %), Boscia albitrunca (3.8 %), Euphorbia rectirama (2.9 %) and Indigofera pechuelii (2.6 %). The riverine forest provides easy access to water, browse, shade and vertical cover. However, some 97 % of Waterval has scarce browse and vertical cover as well as little to no shade. In addition, the northeastern area is steep, 4-6 km from water and bordered by a low-use road. Fortunately, with the exception of community 3, browse is diverse, generally palatable and deciduousness limited to 2-3 months in one major browse species.