Aquatic Sciences

, Volume 68, Issue 3, pp 310–337 | Cite as

Species diversity of the Okavango Delta, Botswana

  • Lars Ramberg
  • Peter Hancock
  • Markus Lindholm
  • Thoralf Meyer
  • Susan Ringrose
  • Jan Sliva
  • Jo Van As
  • Cornelis Vander Post
Overview Article

Abstract.

In the Okavango Delta (about 28,000 km2) the number of identified species is 1,300 for plants, 71 for fish, 33 for amphibians, 64 for reptiles, 444 for birds, and 122 for mammals. The local occurrence of different species of these taxonomic groups in the Okavango Delta is mainly due to a hydrological gradient from permanent streams and swamps to seasonal floodplains, riparian woodlands, and dry woodlands. This level of species diversity is normal for the southern African region, and all analyzed aquatic groups are composed of ubiquitous species with an additional significant proportion of species originating from northern, more tropical systems. Cyclical variations in climate over thousands of years have created a huge wetland complex in the upper Zambezi and Okavango Rivers during wet phases. This wetland complex has fragmented into the Okavango Delta and other large wetlands in Zambia during dry phases. There are no endemic species in the Okavango Delta while the South-central African wetland complex is a centre of endemism. Species diversity of the Okavango Delta is a consequence of this unique environment, with dynamic shifts in flooding patterns that in turn force constant changes in patterns of plant succession and dependent animals. Temporal variations in flooding also cause accumulation and sudden mobilization of nutrients which are readily used by well adapted plant species. As a consequence, locally high biological productivity occurs, which in turn results in high numbers of grazing mammals.

Keywords.

Biodiversity species habitat Africa wetlands Okavango 

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Copyright information

© Eawag 2006

Authors and Affiliations

  • Lars Ramberg
    • 1
  • Peter Hancock
    • 2
  • Markus Lindholm
    • 3
  • Thoralf Meyer
    • 1
  • Susan Ringrose
    • 1
  • Jan Sliva
    • 4
  • Jo Van As
    • 5
  • Cornelis Vander Post
    • 1
  1. 1.Harry Oppenheimer Okavango Research CentreUniversity of BotswanaMaunBotswana
  2. 2.Ecotourism ServicesMaunBotswana
  3. 3.Department of BiologyUniversity of OsloOsloNorway
  4. 4.Munich Technical UniversityMunichGermany
  5. 5.Department of Zoology and EntomologyUniversity of the Free StateBloemfonteinSouth Africa

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