Ecoregions of the Central African Republic

July 31, 2012, 6:48 pm
Content Cover Image

CAR. Source: Brice Blondel for HDPTCAR

The Central African Republic has five ecoregions that occur entirely or partly within its borders:

  1. Northwestern Congolian lowland forests (just in the southwest corner)
  2. Northeastern Congolian lowland forests (in the central southern part of CAR)
  3. Northern Congolian forest-savanna mosaic
  4. East Sudanian savanna
  5. Sahelian Acacia savanna (just in the northern most part of the country)

Ecoregions of the Central African Republic. Source: World Wildlife Fund

Northwestern Congolian lowland forests

The Northwestern Congolian Lowland Forests ecoregion stretches across four countries - Cameroon, Gabon, Republic of Congo, and the Central African Republic (CAR). It is bordered to the north and south by forest-savanna mosaics and to the east by swamp forest, while the western limit grades gradually into the lowland rain forests of the Atlantic Equatorial coastal forest ecoregion.

The Northwest Congolian Lowland Forest ecoregion contains vast tracts of lowland forest, supporting core populations of the western lowland gorilla (Gorilla gorilla gorilla) and large numbers of forest elephant. Species richness and endemism are both high. Logging concessions and associated bushmeat hunting and agricultural expansion are the main threats to the habitats and species. There are some established protected areas, and the gazettement of new protected areas offers good potential for biodiversity conservation in the region.

The Dzanga-Sangha forest in CAR is protected within the Dzanga-Ndoki National Park and the adjacent Dzanga-Sangha Faunal Reserve, totaling 4,347 km2, which is about eight percent of CAR's total closed forest estate. While the forest around Ngotto in CAR currently has no official protected area status, the Forêt de Ngotto (730 km2) is in the final stages of gazettement. One of the largest areas under protection is the Sangha Trinational protected area (10,650 km2), which combines the Nouabalé-Ndoki National Park (over 4,000 km2) in northern Republic of Congo, Dzanga-Sangha complex in the Central African Republic (CAR), and the Lobéké National Park in Cameroon.

Northeastern Congolian lowland forests

The Northeastern Congolian Lowland Forest is located in the northeastern portion of the Democratic Republic of Congo (DRC) and extends into the Southeastern portion of the Central African Republic (CAR).

The Northeastern Congolian Lowland Forests contains endemic species and large areas of forest wilderness with intact animal and plant assemblages. Endemic species include the okapi (Okapia johnstoni), aquatic genet (Osbornictis piscivora), and the Congo peacock (Afropavo congensis). The forests also provide critical habitat for endangered species such as eastern lowland gorilla (Gorilla gorilla graueri). There are some protected areas, but the recent military conflicts in Rwanda, Burundi, and the Democratic Republic of Congo have made these difficult to manage. Threats come from mining, logging, hunting, and agricultural clearance of forest, often by refugees.

Northern Congolian forest-savanna mosaic

The Northern Congolian Forest Savanna Mosaic ecoregion forms the northern border of the Congo watershed, it begins east of the Cameroon highlands and extends east through the Central African Republic, northeastern Democratic Republic of Congo and into southwestern Sudan and a sliver of north-western Uganda. It includes the northernmost savanna woodlands in Africa. Unlike the Zambezian forest-savanna mosaics south and west of the Congo Basin, this narrow transition zone marks an abrupt habitat discontinuity between the extensive Congolian rain forests and Sudanian/Sahelian grasslands. With their characteristically diverse habitat complexes, forest savanna mosaics support a high proportion of ecotonal habitats, which have high species richness and are possible locii of tropical differentiation and speciation.

Increasing human population, poverty, the ongoing civil wars in Sudan and the Democratic Republic of Congo, strife between government and rebel groups in the Central African Republic and armed incursions by well-armed poaching gangs from the Sudan, mean that the northern forest-savanna mosaic faces increased threats. Hunting of animals for food, including from within protected areas, occurs in all areas, as does deforestation.

Political instability has propelled floods of transnational refugees, as well as provided incentive for widespread poaching, exacerbating negative human impact on the natural systems. Warring rebel factions poach valuable game and timber to buy munitions; mass migrations of refugees further tax fuelwood, wildlife in the form of bush meat resources, water, and soils. Ongoing economic, political and social instability have drained the already limited conservation budgets, and parks and protected areas are particularly susceptible to poaching.

The distribution of large mammals has been drastically reduced in recent times, providing evidence of the impact of habitat conversion and overhunting. Hunting camps are found far into the bush, with ivory and other valuable animal products targeted to pay for weapons as well as food. Gallery forests are logged for timber, even though high transportation costs marginalize the profitability of commercial logging ventures. Cutting wood for fuel and charcoal production threatens woodlands and forests where populations become too dense. Refugee camps produce intense local pressure on the environment, and severely degrade their local natural resources.

Climate change is also implicated in the increase of grassland in proportion to forest. Across much of the ecoregion, average rainfall levels have dropped precipitously since the 1970s. Careful monitoring of the dynamics of the forest/grassland ecotones, and the relative advance and retreat of the adjoining habitats, may offer insight into the nature and rate of climate change. Regions closer to the forest zone will continue to see increased human population in response to desiccation.

East Sudanian savanna

caption African elephants (Loxodonta africana), Manoro-Gounda-St. Floris, Central African Republic Photograph by Richard W. Carroll This ecoregion lies south of the Sahel in central and eastern Africa, and is divided into a western block and an eastern block by the Sudd swamps in the Saharan Flooded Grasslands ecoregion. The western block stretches from the Nigeria/Cameroon border through Chad and the Central African Republic to western Sudan. The eastern block is found in eastern Sudan, Eritrea, and the low-lying parts of western Ethiopia, and also extends south through southern Sudan, into northwestern Uganda, and marginally into the Democratic Republic of Congo around Lake Albert.

The East Sudanian Savanna is a hot, dry, wooded savanna composed mainly of Combretum and Terminalia shrub and tree species and tall elephant grass.

Notable threatened mammal species include large herds of elephant (Loxodonta africana, EN) in Chad and Central African Republic, wild dog (Lycaon pictus, EN), cheetah (Acinonyx jubatus, VU), leopard (Panthera pardus, EN) and lion (Panthera leo, VU). Black rhinoceros (Diceros bicornis, CR) and northern white rhinoceros (Ceratotherium simum cottoni, CR) have been extirpated from the ecoregion, although occasional unconfirmed reports of the former (from southern Chad, for example) continue to be received. The eastern giant eland (Taurotragus derbianus gigas) still survives in good numbers in the Central African Republic, especially in the western regions of the country, out of reach from Sudanese poachers. Giant eland are less susceptible to poachers than other more sedentary and less wary antelope species, but have been almost completely eliminated from Sudan. The roan antelope’s (Hippotragus equinus) cautious behavior has also allowed it to withstand poaching pressure to some degree and it is widespread throughout the Central African Republic, in low to moderate densities. However, uncontrolled poaching in Chad and Sudan has resulted in decreasing roan antelope populations in the rest of this ecoregion.

The habitat has been adversely affected by agricultural activities, fire, clearance for wood and charcoal, but large blocks of relatively intact habitat remain even outside protected areas. Populations of some of the larger mammal species have been reduced by hunting, but good numbers of others remain. Although numerous protected areas exist, most are under-resourced "paper parks" with little active enforcement on the ground, and some have suffered from decades of political instability and civil unrest. The protected areas include the Manovo-Gounda-St Floris National Park.

The poor infrastructure and inaccessibility of the region have resulted in little development of tourism and wildlife-related revenue generation schemes, with the notable exception of sport hunting in the Central African Republic. Considerable external support to this ecoregion from multilateral and bilateral aid agencies is likely to be needed for many years to maintain or improve current levels of biodiversity.

Sahelian Acacia savanna

The Sahelian Acacia Savanna stretches across Africa from northern Senegal and Mauritania on the Atlantic coast to Sudan on the Red Sea, varying in width from several hundred to over a thousand kilometers. It covers a small area of the northern most part of the Central African Republic.

Although not particularly rich biologically, these savannas once supported a large and diverse ungulate community. The first European explorers to visit the region found vast herds of game, even larger in number than those of eastern and southern Africa. Sadly, these herds have been reduced to mere remnants due to nearly a century of unregulated over-hunting with modern firearms and vehicles, coupled with habitat loss.

Context

Ecoregions are areas that:

[1] share a large majority of their species and ecological dynamics;
[2] share similar environmental conditions; and,
[3] interact ecologically in ways that are critical for their long-term persistence.

Scientists at the World Wildlife Fund (WWF), have established a classification system that divides the world in 867 terrestrial ecoregions, 426 freshwater ecoregions and 229 marine ecoregions that reflect the distribution of a broad range of fauna and flora across the entire planet.

 

Glossary

Citation

Fund, W. (2012). Ecoregions of the Central African Republic. Retrieved from http://www.eoearth.org/view/article/178648