usaid/nambia environmental threats and opportunities assessment

4. OVERVIEW OF NAMIBIA’S
BIODIVERSITY AND
NATURAL RESOURCES
MANAGEMENT SECTORS
A. WILDLIFE AND CONSERVATION
1. BACKGROUND INFORMATION
Namibia’s major biomes are depicted in Figure 5.
THE TREE AND SHRUB SAVANNA receives the highest precipitation and is dominated by two vegetation
types – i.e., Broad-leafed (in the north east) and Acacia savannas. The sub-humid broad-leafed
woodlands represent Namibia’s most biodiversity rich area. The central acacia savanna (semi-arid) areas
support a moderate to dense cover of shrubs and small trees and suffer from a high prevalence of land
degradation (resulting from poor land management) in the form of bush encroachment.
THE NAMA KAROO supports a high level of species endemism (plants, birds, and reptiles). It covers
most of the southern and southeastern part of the country and extends northwards in a narrow band
along the escarpment – creating a transition zone between semi-arid savanna to the east and hyper-arid
desert to the west. This supports highly varied plant assemblages including: shrubby vegetation and
grasslands in the north and central western plains, dwarf shrub savanna in the south central areas, and
grasslands in the south.
THE NAMIB DESERT is characterized by hyper-aridity, especially along the coast where rainfall is very low
(< 50 mm/y). Ocean fog (which penetrates up to 50-100 km inland) moderates the temperature and
provides a source of moisture that is utilized by highly adapted plants and animals. High dunes
predominate the substrate between Luderitz and Walvis Bay. Vegetation cover on the sandy and gravel
plains that occur in areas where the dunes are absent is sparse and confined to lichens and small plants.
Ephemeral washes and westward flowing rivers (linear oases) that cut through the desert plains are able
to support higher densities of trees and undergrowth and, in some cases, fairly abundant wildlife
populations (including elephant, rhino, giraffe, and arid-adapted ungulates). Occasional springs and seeps
support birds and wildlife away from the river systems. Trees in the ephemeral rivers are maintained by
alluvial aquifers that are susceptible to overabstraction by increasing numbers of upstream boreholes and
small farm dams.
THE SUCCULENT KAROO (the lower Orange river basin) supports an abundant and distinct succulent
vegetation – largely dependent on highly variable winter rainfall. Plant endemism is extremely high in
this zone. The vegetation structure (referred to as dwarf shrubland) shows great variety in response to
the variable landscapes (mountains, inselbergs, gypsum, and sand plains), varying degrees of fog
penetration, and wind patterns.
USAID/NAMIBIA ENVIRONMENTAL THREATS AND OPPORTUNITIES ASSESSMENT 31