Underwater vegetation, Okavango River, Botswana, Africa
Wetland plants in the Okavango Delta
In addition to papyrus, the Okavango Delta is full of other reeds and lilies (Dancing lily, Joining cold fish in the clear Okavango, Underwater networks), whose stems and roots form thick banks. Jacanas walk on the lily pads floating on the surface, and hippos clear paths through the vegetation under water. Other flowers like mistletoe and flame lilies are also found in the Delta.
The delta slopes only slightly along its 250km (155mi) length and the water from rainfall in the catchment area takes five or six months to reach the far end of the swamps. This water is low in nutrients because the soils in the catchment are sandy. And despite evaporation, it does not get saline, because of the way the delta’s vegetation regulates the dispersal of water and sediment and influences the accumulation of salts.
When old channel systems dry out and peat catches fire, nutrients and clays are released and form fertile soils which produce grass on which large herbivores can graze. For a fuller explanation of the role plants play in this system, see the work of the Okavango Research Group at the University of the Witwatersrand in Johannesburg, South Africa.