The Cross-Niger transition forests occupy southeastern Nigeria between the Niger River to the west and the Cross River to the east, spanning the states of Abia, Akwa Ibom, Anambra, Ebonyi, and Imo across low, undulating terrain. Once a mosaic of tropical forest and savanna woodland, the surviving rainforest carries characteristic genera such as Brachystegia, Cola, Ficus, Celtis, and Antiaris, alongside the fan palm Borassus aethiopum, grading into drier mixed forest northward. The climate is wet but becomes drier inland, with rainfall declining from south to north and a dry season from December to February. Biologically the region is transitional between the Upper and Lower Guinean forest blocks yet shows extremely low endemism, with the crested chameleon and Sclater's guenon among its few notable species. It is now one of Africa's most densely populated areas, and intensive farming and logging have left its forests in critical, fragmented condition, with large mammals depleted since the 1940s.
Marker placed inside the RESOLVE 2017 polygon at 5.5°N, 7.4°E.
Climate snapshot for this ecoregion
°C
°F
Current zone range (2011–2040)
13b
Plotwright
CHELSA-derived typical winter month at this ecoregion's bbox grid.
Projected (2041–2070)
13b
Plotwright
Where the CHELSA models say the typical winter month is heading.
Average warming this ecoregion is on track for: +3.4°F by mid-century. SSP3-7.0 (current trajectory) · CHELSA v2.1 bio06 sampled across 10 of 10 points within this ecoregion's bounding box.
At a glance
Dominant biome
Tropical & Subtropical Moist Broadleaf Forests
Realm
Afrotropic
Approximate area
7,998 sq mi
Conservation tier
Nature Imperiled (Dinerstein NNH 4)
About the tropical & subtropical moist broadleaf forests biome
Warm, wet, highly productive forests — including tropical rainforests — with closed canopies, near year-round growing seasons, and the richest terrestrial biodiversity on Earth. Low seasonality and high rainfall sustain dense, layered vegetation from canopy to forest floor.
Catalog plants suited to this ecoregion
No catalog plants intersect this ecoregion's zone range. As the catalog grows to cover this region's climate band, suggestions will surface here.
Collections for this ecoregion
No curated collection's plants all fit this ecoregion's zone range. We surface a collection only when every member would grow here — partial fits get filtered out rather than mislead. As the catalog and the curated set both grow, this section will fill in.
Related ecoregions
Other tropical & subtropical moist broadleaf forests ecoregions to explore: