Congolian swamp forests

• Category: Forest Biomes.
• Geographic Location: Central Africa.
• Summary: A vast, intact swamp forest, one of the largest on the planet, contains many large mammals but is not particularly high in species diversity.

The Congolian Swamp Forests biome of Central Africa stretches from the eastern Republic of the Congo across the Democratic Republic of the Congo (DRC) to encompass 47,880 square miles (124,000 square kilometers), including the central Congo Basin and some of the Congo River’s largest tributaries. The topography is a large alluvial plain called the Cuvette Congolaise, thought by some researchers to have lain under a lake at one time. It is generally agreed that the swamp forests retreated to along the river’s edge during colder, drier Pleistocene ice ages and expanded during warmer, wetter periods.

Annual precipitation is approximately 70 inches (180 centimeters). The region has limited seasons due to its equatorial location. Although seasons are not highly pronounced, habitats can be flooded to a depth of up to three feet (one meter), yet dry out for short periods annually. Habitats include not only swamp forests but also open water, seasonally flooded forest, dryland forest, and seasonally inundated savannas.

Essential Vegetation

The eastern extent of the swamp forests reaches to the Boyoma Falls (formerly the Stanley Falls) area near Kisangani. Swamp forest vegetation includes Guibourtia demeusei, Mitragyna spp., Symphonia globulifera, Entandrophragma palustre, Uapaca heudelotii, Sterculia subviolacea, Alstonia congensis, and species of Manilkara and Garcinia.

More frequently flooded swamps can harbor large, nearly monocultural expanses of Raphia palm. Levee forests often host liana species along with Gilbertiodendron dewevrei and Daniellia pynaertii. Open areas harbor giant ground orchids (Eulophia porphyroglossa), while riverbanks can be lined with arrowroot (Marantochloa spp).

Swamp Forest Animals

Large mammals include the endangered western lowland gorilla (Gorilla gorilla gorilla), chimpanzee (Pan troglodytes), and forest elephant (Loxodonta africana cyclotis). Larger numbers of forest buffalo (Sycerus caffer nanus) were once present but have been overhunted. Elephants, gorillas, and the remaining forest buffalo use open grassland areas within the swamps for refuge and feeding.

The Congo River, up to nine miles (15 kilometers) wide in places, acts as a significant barrier to movement of wildlife, especially primates. Occurring only on the left bank, or facing downriver, are communities of the Angolan colobus monkey (Colobus angolensis); Wolf’s guenon, or Wolf’s mona monkey (Cercopithecus wolfi); bonobo (Pan paniscus); golden-bellied mangabey (Cercocebus chrysogaster); black-crested mangabey (Lophocebus aterrimus); southern or Angolan talapoin (Miopithecus talapoin); and dryad guenon (Cercopithecus dryas).

Their counterparts on the right bank, facing upriver, include the crowned guenon (Cercopithecus pogonias), chimpanzee (Pan troglodytes), agile mangabey (Cercocebus agilis), and gray-cheeked mangabey (Lophocebus albigena). A minor number of primate species are found on both sides of the Congo River; counted among them is Allen’s swamp monkey (Allenopithecus nigroviridis).

One of the great and abiding myths of the region is found at Lake Tele, or Lac Télé-Likouala-aux-Herbes, in the Republic of the Congo, where a giant, dinosaur-like animal called Mokele Mbembe is said to live.

Human Impact and Conservation

Human populations are relatively low in the swampland and tend to concentrate in villages along river settings. Threats to wildlife species such as elephants and bonobos include logging and poaching, especially closer to the Congo River, due to its ease of accessibility both to wildlife and markets. Salonga National Park in the DRC contains the most swamp forest area under official protection, while a large Ramsar Wetland of International Importance site covers 1,695 square miles (4,390 square kilometers) in the Republic of the Congo. One leading characteristic of the Congolian swamp forest is its relative inaccessibility, but new roads built for logging, mining, and infrastructure development continue to increase access by both development workers and poachers. The bonobo population is fragmented and decreasing.

Salonga National Park, the largest protected area of dense humid forest in Africa at 8.2 million acres (3.3 million hectares), is also listed as a United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage Site. UNESCO had placed the site on its endangered list in 1999 but removed it from the list in 2021. The site had been endangered due to military conflict and poaching. However, UNESCO noted the DRC had increased conservation measures by the early 2020s. Despite the improvements, UNESCO said that the government of the DRC needed to implement a better management plan to ensure adequate conservation measures continue. Two major Indigenous groups live within the park: the Kitawala, with an estimated population between 3,000 and 4,000 in the northeast section, and the Iyaelima people in the south, with an estimated population of 2,500 inhabitants in eight villages.

The effect of decades of conflict in the eastern Congo region has stressed cash economies and made local populations more dependent on natural resources. Fishing makes up approximately 65 percent of incomes in some communities. Enforcement of poaching laws can be difficult. Once apprehended, transporting an offender to a nearby tribunal may require 125 miles (200 kilometers) of travel by foot or bicycle. The scale of conservation needed in the Congolian swamp forests requires a “landscape” approach that will incorporate the economy of local inhabitants.

At least two-thirds of the Congolian swamp forests are thought to be under threat of deforestation. Such a scenario would create havoc in efforts to slow or reduce global warming, as this biome is a major contributor to the natural sequestration of carbon. Like moist forests and boglands elsewhere, these swamp forests absorb carbon-heavy gas from the atmosphere—an ecological service that grows more important as concentrations of greenhouse gases continue to increase. The Congo Basin peatlands, including swamp forests, store an estimated thirty billion metric tons of carbon, making them one of the largest tropical carbon reserves in the world.

Bibliography

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