The Niger Delta swamp forests is a tropical moist forest ecoregion in southern Nigeria. It consists of freshwater swamp forests in the Niger Delta of the Niger River. This swamp forest is the second largest in Africa after the Congolian swamp forests. Although there are large cities just outside the ecoregion, the area has been relatively isolated by the difficulty of building roads across the swamps, although this is changing with development of oil and logging industries. Scientific surveys have only begun in recent years, and new species were being identified into the 1990s. Crude oil exploration and pollution has been a threat to forests in the Niger Delta region.
Location and description
The Niger Delta swamp forests ecoregion covers a triangular territory at the mouth of the Niger River. The southern edge is set back about 10 km from the Gulf of Guinea, buffered by the Central African mangroves ecoregion where the effects of salt water are more pronounced. The western border of the ecoregion is formed along the Benin River, the northern tip is just north of the city of Aboh, and the eastern edge runs along the Imo River. The city of Port Harcourt is in the southeast corner of the ecoregion. The Niger Delta region of Nigeria is located along the Gulf of Guinea. It is the largest delta in Africa and the third largest delta in the world and also the most extensive marshland in West and Central Africa. The region spans from Aboh (5°33′49″ N and 6°31′38″ E) Ndokwa East, Delta State in the North to Palm Point (4°16′22″ N and 6°05′27″ E) Bayelsa State in the south. The east-west boundary lies between Benin or Ethiope River estuary (5°44′11″ N and 5°3′49″ E) Delta State in the west and Imo River estuary (4°27′16″ N and 7°35′27″ E) Ikot Abasi, Akwa Ibom State to the east.
The Niger Delta is built up from silt deposits from the Niger River. The landscape is flat with meandering branches of the main river. The Niger Delta is made up of various networks of rivers and creeks mostly distributaries of the Niger River. The soils of the delta vary by the shifting rivers and creeks, with sand and loam marking the remains of old levees, water-logged heavy clay in the backswamps behind the levees, and silty loam and clay on the higher ground. Niger delta can be delineated into four different ecological zones: namely mangrove forest, freshwater swamp forest, lowland rain forest and other vegetation occasioned by human impact on the environment. Mangroves are intricate intertidal forest that grow at the intersection within dry land and open sea in tropical regions and is the source of huge biological and none living resources. Nigeria’s mangrove forest is located in the Niger delta region and is arguably the most exploited mangrove forest in the world. The Niger Delta region of Nigeria has a land mass of about 70000 km² representing 7.5% of Nigeria's land mass. It is made up nine oil – producing states viz; Abia, Akwa Ibom, Bayelsa, Cross River, Delta, Edo, Imo, Ondo and Rivers. These states contain more than 40 ethnic groups and have 185 Local Government Areas (LGAs) and inhabitants that speak about 250 different dialects. The Niger Delta region is amongst the highest hydrocarbon-rich regions on planet earth. Exploration and exploitation of hydrocarbons started in the region in 1957 with discovery of oil at Oloibiri in River State and has since been going on till date (2023).
Climate
The ecoregion has a tropical monsoon climate, according to the Köppen climate classification (Am). This climate is characterized by a distinct dry season and rather constant temperatures throughout the year, with the average temperature of each month above 18 °C (64 °F). Less than 60 mm, but more than (100-(average/25) mm, of precipitation fall during the driest month. This climate is in the middle of a tropical savannah and a tropical rainforest. The rainy season runs from March–April to October. Precipitation ranges from 2,500 mm/year in the north to 4,000 mm/year along the coast in the south. Relative humidity is 90-100% for most of the year.
Degradation is putting freshwater marsh forests in the Niger basin in danger, so it's important to comprehend their composition, distribution, and trends. In a study that evaluated the floristic diversity and composition of sixteen one-hectare forest patches, 116 species from 82 genera and 36 families were discovered. Sites that were disturbed exhibited reduced species richness but greater species variety and stem density. The study highlights the necessity for species stability and biodiversity and stresses the significance of focused conservation in damaged areas.