What is a peat swamp forest?
Peat swamp forests known as idobo in the Zulu language are moist forests that are formed where waterlogged soil prevents dead leaves and wood from fully decomposing. Over time, this creates a thick layer of acidic peat inhabited by unique plant communities adapted to these wet, acidic, nutrient and oxygen poor soils.
Swamp fig Ficus trichopoda growing on the banks of the aManzimnyama river in the eMalangeni peat swamp forest
Peat swamp forests form in areas where saturated soils or frequent flooding prevent organic material from fully decomposing. As this organic material slowly accumulates, it retains even more water through capillary action, up to 13 times its weight, acting as a giant sponge that holds in the moisture. Peat swamps known as ixhaphozi in the Zulu language eventually form a dome of wet organic material that can rise above the surrounding flood levels.
It takes thousands of years for peatlands to form, with organic matter accumulating at 0.5 – 2 mm per year . Peat layers over 4 meters are common, while depths of up to 20 meters have been reported.
Above is a photograph of the water well known as Kwa Ginga that has been used by the eMalangeni community for over 100 years in the eMalangeni peat swamp forest. the well was named after the royal son of Makhuza Tembe
The unique hydrology of this habitat provides a critical buffer against flooding during the wet season, and insurance against drought in the dry season. The swamp retains heavy rainfall and slowly releases the moisture over an extended period of time. As climate change results in more extreme weather events and irregular precipitation, this ecosystem service is becoming even more critical.
The jewel of the eMalangeni Forest Euphaedra neophron, the gold banded forester, is a butterfly in the family Nymphalidae
In many ways, Peat swamp forests are similar to other tropical and sub-tropical lowland forests such as in the size and density of large trees. Unique biological communities are specially adapted to thrive in the flooded, oxygen poor environment.
Many tree species have large buttresses and Seepage of black water stained by tannins in the eMalangeni peat swamp forest to hold themselves up in the soft peat soil. Others have pneumatophores or are covered with lenticels at the base of the stem to permit gas exchange with the air, as soils are waterlogged and often inundated.
The red mangrove Rhizophora mucronata with prop roots to support it in the unstable peat soil
Wetland associated plants are also very common in the understory and on the forest floor, epiphytes growing on the trees right up into the canopy are numerous, such as ferns and orchids.
The epiphytic fern Microsorum punctatum growing on threes in the eMalangeni peat Swamp forest in the Kosi Bay System
Peat Swamp Forests supply numerous ecosystem services to human communities. These are natural services that are beneficial to humans but not paid for directly, these services include timber and non timber forest products such as honey, nuts, fruits, medicines, latex, dyes, and fiber. Peat swamps also provide fresh water and fish to local communities.
Peat Swamp forests regulate landscape hydrology, and have been described as “landscape sponges”, absorbing excess rainwater during wet seasons and during extreme storm events, and steadily releasing stored water during dry spells or droughts. They also serve as biofilters which trap sediments and excess nutrient runoff from agricultural activities upstream. In their natural state, peat swamps are also globally significant sinks of atmospheric carbon.
The Narina trogon Apaloderma narina is a most spectacular forest bird that is to be found in the eMalangeni peat swamp forest.
In South Africa peat swamp forests are highly threatened ecosystems, being the second rarest forest type in the whole country and only occur in isolated patches from the Mozambique border a few kilometers north of the Kosi Bay System and the eMalangeni peat swamp forest to just south of the Msikaba River in the Eastern Cape
The coastal peat swamp forests on the flat coastal plain of Maputaland which include the eMalangeni coastal peat swamp forest the largest of the peat swamp forests represent seventy five percent of all the swamp forest found in South Africa.
The eMalangeni coastal peat swamp forest which has a total area of 880 ha feeds the Siyadla- aManzimnyama river that flows through it is the largest peat swamp forest in South Africa. The eMalangeni coastal peat swamp forest which is situated immediately south of lake aManzimnyama is the main source of fresh water for the Kosi Bay Lake System.
The water that is released by the eMalangeni peat forest into the aManzimnyama river (black water river) is stained dark brown by the tannins that leach from the fallen leaves and peat, hence the name aManzimnyama the Zulu name for black water.
The aManzimnyama river, black water river that flows through the eMalangeni peat swamp forest
The eMalangeni peat swamp forest displays a gradient between wet and dry swamp forest. Raphia australis, Syzygium cordatum, Schefflera umbellifera generally grow under drier conditions, while Syzygium cordatum, Voacanga thouarsii grow in intermediate conditions and Ficus trichopoda dominate the Riverine area of the forest.
The drier swamp forest on the western shore of Lake aManzimnyama has large stands of the endemic Kosi Bay Palm, Raphia australis palms. Syzygium cordatum which exhibits a grade of hydrological preferences, is mostly absent in the very dry Raphia australis and very wet Ficus trichopoda dominated vegetation areas.
The Kosi Bay palm Raphia australis growing in the eMalangeni peat swamp forest
Heavily disturbed areas of the forest which were caused primarily due to previous agricultural practices are characterized by a general lack of a fully developed tree canopy as well as hydrological modifications made to the peat by means of drainage ditches. Natural gaps in the forest are created where stands of the monocarpic Raphia australis palms die and fall over after flowering.
Traditionally the light and durable wood of the endemic Raphia australis palms has been a very important component in the livelihood of the local peoples, the collection of fallen rachi is used for construction material for houses as well as canoes and rafts to cross the aManzimnyama river.
A traditional boat used on the lakes at Kosi Bay made of the leaf rachi of the Kosi Bay palm Raphia australis
In the past traditional farming practices enabled the local communities who have been relocated to live in harmony with their wetlands for several generations, as they rotated their gardens on a chosen peatland and still have wetland habitat that remain intact in spite of their presence over several centuries.
Tourism in this largely pristine peat swamp forest area that has been placed under the protection of the iSimangaliso Wetland Park Authority is playing an increasingly important role in the local economy as access and tourist numbers improve due to better infrastructure, such as new roads and lodges, and wider circulated publicity.
An African Jacana Actophilornis africana and young on the lily pads of the blue water lily Nymphaea nouchali in the eMalangeni peat forest
Guided excursions that offer far more scientific knowledge and interesting facts in regards to the plants birds animals and other creatures encountered in the forest than the usual guided can be conducted in English, Zulu and German into the eMalangeni Swamp Forest and surrounding area including the nearby Tembe Elephant Park can be arranged and tailored to the individual needs of the client/s no matter at which establishment one will be staying at while at Kosi Bay. Please visit one of my websites for contact details.
Michael Hickman
29.04.21
please visit my websites
www.ecoman.co.za
www.hlem.co.za
as well as my other blogs at
http://luthulienvironment.blogspot.com/
http://ecomandurban.blogspot.com/
