Cross-Niger transition forests
Encyclopedia
The Cross-Niger transition forests are a tropical moist broadleaf forest
ecoregion
of southeastern Nigeria
, located between the Niger River
on the west and the Cross River
on the east. Once a rich mixture of tropical forest and savanna woodland covered these low, rolling hills but today this is one of the most densely-populated areas of Africa and today most of the forest has been removed and the area is now grassland.
, Akwa Ibom
, Anambra, Ebonyi, and Imo
, covering an area of 20700 square kilometres (7,992.3 sq mi). The Niger River separates the Cross-Niger transition forests from the Nigerian lowland forests to the west, which probably resembles most closely the original environment of the Cross-Niger ecoregion. To the south and south-west lies the Niger Delta swamp forests. To the north, the Cross-Niger transition forests yield to the Guinean forest-savanna mosaic
of the drier interior.
The climate is wet, becoming drier further inland, with a dry season from December to February.
of West Africa and the Lower Guinean-Congolian forests of Central Africa, which constitute the largest blocks of tropical moist forest on the African continent. Trees in the area include Afzelia
, which is cultivated for timber, and the Borassus aethiopum palm.
and crested chameleon (Chamaeleo cristatus). The Niger River
has always been a substantial barrier to movement of wildlife in and out of the region. Large mammals have been depleted in the area since the 1940s and there is now so little wildlife remaining in the area that even bats and frogs are now trapped and eaten.
together with some enclaves of sacred forest, which are continually disappearing as village life is eroded, and patches of riverine forest. There are forest reserves in Anambra and elsewhere but these last are mostly for the purpose of cultivating timber rather than preserving the original environment.
Tropical and subtropical moist broadleaf forests
Tropical and subtropical moist broadleaf forests , also known as tropical moist forests, are a tropical and subtropical forest biome....
ecoregion
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
of southeastern Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
, located between the Niger River
Niger River
The Niger River is the principal river of western Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in southeastern Guinea...
on the west and the Cross River
Cross River (Nigeria)
Cross River is the main river in southeastern Nigeria and gives its name to Cross River State.It originates in Cameroon, where it takes the name of the Manyu River....
on the east. Once a rich mixture of tropical forest and savanna woodland covered these low, rolling hills but today this is one of the most densely-populated areas of Africa and today most of the forest has been removed and the area is now grassland.
Location and description
The ecoregion extends across the Nigerian states of AbiaAbia State
Abia State is a state in southeastern Nigeria. The capital is Umuahia, although the major commercial city is Aba, formerly a British colonial government outpost. The state was created in 1991 from part of Imo State and its citizens are predominantly Igbo people...
, Akwa Ibom
Akwa Ibom
Akwa Ibom is a state in Nigeria named after the Qua Iboe river. It is located in the coastal South-Southern part of the country, lying between latitudes 4°321 and 5°331 North, and longitudes 7°251 and 8°251 East...
, Anambra, Ebonyi, and Imo
Imo State
Imo State is one of the 36 states of Nigeria and lies to the south of Nigeria with Owerri as its capital and largest city.-History:Imo State came into existence in 1976 along with other new states created under the leadership of the late military ruler of Nigeria, Murtala Muhammad, having been...
, covering an area of 20700 square kilometres (7,992.3 sq mi). The Niger River separates the Cross-Niger transition forests from the Nigerian lowland forests to the west, which probably resembles most closely the original environment of the Cross-Niger ecoregion. To the south and south-west lies the Niger Delta swamp forests. To the north, the Cross-Niger transition forests yield to the Guinean forest-savanna mosaic
Guinean forest-savanna mosaic
The Guinean forest-savanna mosaic is an ecoregion of West Africa, a band of interlaced forest, savanna, and grassland running east to west and dividing the tropical moist forests near the coast from the West Sudanian savanna of the interior.-Setting:...
of the drier interior.
The climate is wet, becoming drier further inland, with a dry season from December to February.
Flora
The traditional flora and fauna of the ecoregion is "transitional", blending elements from the Upper Guinean forestsUpper Guinean forests
The Upper Guinean forests is a tropical moist forest region of West Africa. The Upper Guinean forests extend from Guinea and Sierra Leone in the west through Liberia, Côte d'Ivoire and Ghana to Togo in the east, and a few hundred kilometers inland from the Atlantic coast. A few enclaves of montane...
of West Africa and the Lower Guinean-Congolian forests of Central Africa, which constitute the largest blocks of tropical moist forest on the African continent. Trees in the area include Afzelia
Afzelia
Afzelia is a genus in the subfamily Caesalpinioideae of the family Fabaceae . The thirteen species all are trees, native to tropical Africa or Asia.- Uses :...
, which is cultivated for timber, and the Borassus aethiopum palm.
Fauna
Small areas of protected forest do remain within the grassland and these are home to animals such as Sclater's GuenonSclater's Guenon
Sclater's guenon , also known as Sclater's monkey and the Nigerian monkey, is an Old World monkey that was first described by Reginald Innes Pocock in 1904 and named after Philip Sclater. It is an arboreal and diurnal primate that lives in the forests of southern Nigeria...
and crested chameleon (Chamaeleo cristatus). The Niger River
Niger River
The Niger River is the principal river of western Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in southeastern Guinea...
has always been a substantial barrier to movement of wildlife in and out of the region. Large mammals have been depleted in the area since the 1940s and there is now so little wildlife remaining in the area that even bats and frogs are now trapped and eaten.
Threats
The ecoregion has sustained a dense human population for centuries, and much of the original forest cover has been cleared for agriculture, forest plantations, and urban developments such as the oil refineries of Port Harcourt. The few remaining enclaves of native forest include the Stubbs Creek Forest Reserve in Akwa IbomAkwa Ibom
Akwa Ibom is a state in Nigeria named after the Qua Iboe river. It is located in the coastal South-Southern part of the country, lying between latitudes 4°321 and 5°331 North, and longitudes 7°251 and 8°251 East...
together with some enclaves of sacred forest, which are continually disappearing as village life is eroded, and patches of riverine forest. There are forest reserves in Anambra and elsewhere but these last are mostly for the purpose of cultivating timber rather than preserving the original environment.