Cape Lowland Freshwater Wetland
Encyclopedia
Cape Lowland Freshwater Wetland is a critically endangered
vegetation type of the Western Cape
, South Africa
.
, South Africa
, on freshwater floodplains, along the lower stretches of rivers and around seasonal vleis
and estuaries
. The terrain is typically flat and the soil is rich and silty. It is restricted to a winter rainfall area.
This used to be one of the major ecosystems on the Cape Flats
of Cape Town. The Cape Flats used to have a great many wetland
s, river
s and seasonal vleis
, but these have largely been drained and built over for housing. A few remain at places such as Rondevlei
.
), Restios
, sedge
s, grasses, floating aquatics and a great many species of shrub. Plant cover is very high.
Sedgelands predominate on the floodplains, floating aquatics grow in the open pools, taller shrubs and small trees grow in drier soils (eg. Erica
and Restio
sp.) and the taller, bigger reed-beds dominate on the fringes of permanent water. Some of the most noticeable and dominant species are Senecio halimnifolius, Paspalum vaginatum, Pennisetum macrourum, Triglochin bulbosa, Bolboschoenus maritimus
and Juncus krausii.
Plant species which are endemic to this vegetation type include: Passerina paludosa, Aponogeton angustifolius, Aponogeton distachyos, and Cotula myriophylloides.
This ecosystem is not particularly rich in endemics (by Cape Floristic Region
standards) but is an exceptionally rich and important habitat for the Waterbirds and Frog
s of the Cape. It is also the breeding ground of the endangered Western Leopard Toad
.
(Eichornia crassipes), Red River Gum (Eucalyptus cladocalyx
) and Port Jackson
(Acacia saligna
), as well as the draining and diversion of water for agricultural reasons and development. A significant proportion of these wetlands have now been transformed and lost and the ecosystem as a whole is now classed as endangered. All remaining wetlands are protected by national legislation.
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
vegetation type of the Western Cape
Western Cape
The Western Cape is a province in the south west of South Africa. The capital is Cape Town. Prior to 1994, the region that now forms the Western Cape was part of the much larger Cape Province...
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
Environment
This type of riparian vegetation and its accompanying ecosystem is found in the Western CapeWestern Cape
The Western Cape is a province in the south west of South Africa. The capital is Cape Town. Prior to 1994, the region that now forms the Western Cape was part of the much larger Cape Province...
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, on freshwater floodplains, along the lower stretches of rivers and around seasonal vleis
Vlei
The word vlei is used predominantly in South Africa. In most instances a vlei is a shallow minor lake of a seasonal or intermittent nature. It even might refer to seasonal ponds or marshy patches where frogs and similar marsh dwellers breed, but too minor to be granted recognition in the form of a...
and estuaries
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
. The terrain is typically flat and the soil is rich and silty. It is restricted to a winter rainfall area.
This used to be one of the major ecosystems on the Cape Flats
Cape Flats
The Cape Flats is an expansive, low-lying, flat area situated to the southeast of the central business district of Cape Town. To many people in Cape Town, the area is known simply as 'The Flats'....
of Cape Town. The Cape Flats used to have a great many wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
s, river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
s and seasonal vleis
Vlei
The word vlei is used predominantly in South Africa. In most instances a vlei is a shallow minor lake of a seasonal or intermittent nature. It even might refer to seasonal ponds or marshy patches where frogs and similar marsh dwellers breed, but too minor to be granted recognition in the form of a...
, but these have largely been drained and built over for housing. A few remain at places such as Rondevlei
Rondevlei
The Rondevlei Nature Reserve is located in Grassy Park, a suburb of Cape Town, South Africa. The bird sanctuary covers approximately 2.2 square kilometres of mostly permanent wetland and consists of a single large brackish lagoon...
.
Ecology
The flora consists of a range of species of tall reed (eg. Phragmites australis, Typha capensisTypha
Typha is a genus of about eleven species of monocotyledonous flowering plants in the family Typhaceae. The genus has a largely Northern Hemisphere distribution, but is essentially cosmopolitan, being found in a variety of wetland habitats...
), Restios
Restionaceae
Restionaceae, also called restiads, is the botanical name for a family of rush-like flowering plants native to the Southern Hemisphere.- Description :...
, sedge
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
s, grasses, floating aquatics and a great many species of shrub. Plant cover is very high.
Sedgelands predominate on the floodplains, floating aquatics grow in the open pools, taller shrubs and small trees grow in drier soils (eg. Erica
Ericaceae
The Ericaceae, commonly known as the heath or heather family, is a group of mostly calcifuge flowering plants. The family is large, with roughly 4000 species spread across 126 genera, making it the 14th most speciose family of flowering plants...
and Restio
Restionaceae
Restionaceae, also called restiads, is the botanical name for a family of rush-like flowering plants native to the Southern Hemisphere.- Description :...
sp.) and the taller, bigger reed-beds dominate on the fringes of permanent water. Some of the most noticeable and dominant species are Senecio halimnifolius, Paspalum vaginatum, Pennisetum macrourum, Triglochin bulbosa, Bolboschoenus maritimus
Bolboschoenus maritimus
Bolboschoenus maritimus is a species of flowering plant from family Cyperaceae. Common names for this species include sea clubrush, cosmopolitan bulrush, alkali bulrush, saltmarsh bulrush, and bayonet grass...
and Juncus krausii.
Plant species which are endemic to this vegetation type include: Passerina paludosa, Aponogeton angustifolius, Aponogeton distachyos, and Cotula myriophylloides.
This ecosystem is not particularly rich in endemics (by Cape Floristic Region
Cape floristic region
The Cape Floristic Region is a floristic region located near the southern tip of South Africa. It is the only floristic region of the Cape Floristic Kingdom, and includes only one floristic province, known as the Cape Floristic Province.The Cape Floristic Region, the smallest of the six recognised...
standards) but is an exceptionally rich and important habitat for the Waterbirds and Frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s of the Cape. It is also the breeding ground of the endangered Western Leopard Toad
Western Leopard Toad
The Western Leopard Toad is a species of toad in the Bufonidae family.The species is endemic to the areas of Cape Town and the eastern coastline of the South-western Cape, South Africa...
.
Threats and Conservation
These ecosystems are threatened by invasive alien plants such as Kikuyu grass, Water HyacinthWater hyacinth
The seven species of water hyacinth comprise the genus Eichhornia. Water hyacinth are a free-floating perennial aquatic plant native to tropical and sub-tropical South America. With broad, thick, glossy, ovate leaves, water hyacinth may rise above the surface of the water as much as 1 meter in...
(Eichornia crassipes), Red River Gum (Eucalyptus cladocalyx
Eucalyptus cladocalyx
The Sugar Gum is a eucalypt from South Australia. It is found naturally in three distinct populations - in the Flinders Ranges, Eyre Peninsula and on Kangaroo Island. Sugar Gums from the Flinders Ranges reach up to 35m in height and have the classic "gum" habit - with a straight trunk and steep...
) and Port Jackson
Port Jackson
Port Jackson, containing Sydney Harbour, is the natural harbour of Sydney, Australia. It is known for its beauty, and in particular, as the location of the Sydney Opera House and Sydney Harbour Bridge...
(Acacia saligna
Acacia saligna
Acacia saligna, commonly known by various names including coojong, golden wreath wattle, orange wattle, blue-leafed wattle, Western Australian golden wattle, and, in Africa, Port Jackson willow, is a small tree in the family Fabaceae...
), as well as the draining and diversion of water for agricultural reasons and development. A significant proportion of these wetlands have now been transformed and lost and the ecosystem as a whole is now classed as endangered. All remaining wetlands are protected by national legislation.
See also
- Biodiversity of Cape TownBiodiversity of Cape Town- Floristic region :The city of Cape Town lies within the Cape Floristic Kingdom . - Vegetation types :...
- Cape Floristic RegionCape floristic regionThe Cape Floristic Region is a floristic region located near the southern tip of South Africa. It is the only floristic region of the Cape Floristic Kingdom, and includes only one floristic province, known as the Cape Floristic Province.The Cape Floristic Region, the smallest of the six recognised...
- Cape Flats Sand FynbosCape Flats Sand FynbosCape Flats Sand Fynbos , previously known as Sand Plain Fynbos, is a critically endangered vegetation type that occurs only within the city of Cape Town, including the Cape Flats district. Less than 1% of this unique lowland Fynbos vegetation is conserved.-Description:This is the richest and most...
- FynbosFynbosFynbos is the natural shrubland or heathland vegetation occurring in a small belt of the Western Cape of South Africa, mainly in winter rainfall coastal and mountainous areas with a Mediterranean climate...