An ecoregion is defined as “a large unit of land or water containing a geographically distinct assemblage of species, natural communities, and environmental conditions” (WWF International). The classification system developed by World Wide Fund for Nature describes:
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867 terrestrial ecoregions;
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426 freshwater ecoregions; and
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229 coast and shelf ecoregions.
Definitions of all ecoregions including information about location, biodiversity features and causes for concern can be found at The Encyclopaedia of Earth and at National Geographic
Ecoregions in the Kunene River basin.
Source: AHT GROUP AG 2010, after WWF 2004
( click to enlarge )
The Ecoregions within the Kunene River Basin are:
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Angolan montane forest-grassland mosaic;
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Angolan Miombo woodlands;
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Angolan Mopane woodlands;
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Zambezian Baikiaea woodlands;
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Angolan scarp savanna and woodlands;
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Namibian savanna woodlands;
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Koakoveld desert; and
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Kalahari Acacia Baikiaea woodlands.
The Namib Desert stretches along the coast of Namibia to form some of the driest areas in the world. Gently sloping toward the Atlantic Ocean, it is dominated by large red sand dunes up to 300 m high. The northern part of the Namib Desert is the KaokoveldDefined through sand dunes, valleys and gravel plains, the Kaokoveld is rich in biodiversity. Sporadic thunderstorms and small waterholes provide sustenance to many species. The Kaokoveld Desert comprises a unique array of species, including at least seven endemic species. The most unusual plant found in the Kaokoveld is the Welwitschia. Individual plants can grow up to 2 500 years old.
 The Welwitschia plant (Welwitschia mirabilis). Source: Gottrop 2004 ( click to enlarge ) |
The Angolan montane forest-grassland mosaic combines a variety of vegetation types including small areas of montane forest, reaching up to 2 600 m, surrounded by open grasslands. The forest patches differ very much from the surrounding habitats. Little is known about this ecoregion. Like many other areas of Angola it was little studied before the country’s civil conflict or since.
The Angolan Miombo woodlands cover most of central Angola and extend north into the Democratic Republic of Congo. It is part of the larger Miombo ecosystem that covers much of eastern and southern Africa. The flora is woodland and moist broadleaf savanna with open grassland between these areas. Fauna inhabiting the area contains a number of bird species, including the endemic Black-tailed Cisticola (Cisticola melanura). Mammals, including large mammals such as giraffes, hippos and zebras and their predators such as lions, leopards and cheetahs as well as smaller carnivores like wild cats live in this habitat. The only endemic mammal is the Vernay’s Climbing Mouse (Dendromus vernayi). The woodlands was home to large population of elephants and black rhinoceros, but during the conflict their populations decreased significantly.
The Angolan Mopane woodlands are located in northern Namibia and southwestern Angola. This ecosystem surrounds the Etosha Pan, which is considered a separate ecoregion. The name giving Mopane tree is the distinctive feature. It is a single-stemmed tree in some places up to 10m high and in some places not much more than a shrub. The tree has a rough bark and sparse crown, but its leaves are beautifully shaped like butterflies.
The Zambezian Baikiaea woodlands lie between 800 and 1 000 m and border the Kalahari of Zambia, in the south-east of Angola, and north-east of Namibia. They have a hot, semi-arid climate. The woodland is a habitat for a variety of life with a variation of riverine areas and wetlands. The areas also support grazing species, more than 400 bird species (including the rare black-checked lovebird) and at least 5 endemic species of reptiles. Part of the ecoregion lies in protected areas, and because of the few people living here the ecoregion has not been modified or fragmented.
The Angolan scarp savanna and woodlands rise from sea level to 1 000 m along the western part of Angola’s high plateau. This large, diverse ecoregion presents many habitat types including rain forest, mangrove forest, cloud forest, grassland and swamp. The ecoregion was long isolated from other ecosystems, which allows many endemic or near-endemic species to evolve. The region is literally unexplored.
The Namibian Savanna woodland forms a transition zone between the extremely arid Namib Desert and the central highland plateau. The landscape varies extremely from semi-arid zones to cool and wet condition at the summit of Brandberg Mountain. This explains the high number of unique species and endemism. This is the home of Hartmann’s mountain zebra, the only large mammal endemic to Namibia, as well as desert elephants and black rhinoceros.
The Kalahari Acacia Baikiaea woodlands are located in north-west Namibia and Botswana. The flat sandveld landscape of this ecoregion is home to more than 130 mammals and around 460 species of birds and the vegetation remained largely intact. Many of the animals here, such as the black rhinoceros and brown hyena, are endangered.
The Xeric freshwaters and endorheic (closed) basins: Namib ecoregion is one of the most arid areas on earth, but it also holds a variety of small wetland ecosystems. It lies at the Atlantic coast, mainly in Namibia, but extends into southwest Angola. The Kunene River is the only perennial river here; all others are ephemeral. The climate is very harsh, extremely hot, with very little and unpredictable rainfall and high evaporation rates. Despite the aridity, there are several types of wetland in the Namib Desert like pools or pans, which remain in the riverbeds after the river stopped flowing.
