The Cross-Sanaga-Bioko coastal forests are a tropical moist broadleaf forest ecoregion of west-central Africa, spanning southeastern Nigeria, southwestern Cameroon, and the lowlands of the island of Bioko in Equatorial Guinea, running from the Cross River south to the Sanaga River and reaching up to 300 km inland from the Atlantic coast. The dominant habitat is coastal evergreen rainforest, grading into mixed moist semi-evergreen forest further inland, with plant families such as Annonaceae, Leguminosae, Euphorbiaceae, Rubiaceae, and Sterculiaceae well represented. This is one of the wettest parts of tropical Africa, with heavy rainfall throughout the year, humidity that rarely drops below 90 percent, and rainfall exceeding 10,000 mm per year in the southwestern foothills of Mount Cameroon while averaging around 3,000 mm along the coast and roughly 2,000 mm inland. The ecoregion is exceptionally rich in endemic plants and supports some of the highest numbers of forest-restricted birds and mammals in Africa, including the Cross River gorilla and Preuss's red colobus, with a 2017 assessment finding that about 26 percent of the region lies within protected areas such as Korup and Cross River National Parks. For gardeners, it is a useful reminder that its native flora is adapted to constant warmth, very high humidity, and abundant year-round rainfall rather than seasonal drought.
Marker placed inside the RESOLVE 2017 polygon at 5.9°N, 9.2°E.
Climate snapshot for this ecoregion
°C
°F
Current zone range (2011–2040)
12b-13b
Plotwright
CHELSA-derived typical winter month at this ecoregion's bbox grid.
Projected (2041–2070)
13a-13b
Plotwright
Where the CHELSA models say the typical winter month is heading.
Average warming this ecoregion is on track for: +3.7°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
20,101 sq mi
Conservation tier
Nature Could Reach Half Protected (Dinerstein NNH 2)
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
Computed from each plant's stated USDA zone range against this ecoregion's CHELSA-derived current zone range, with the CHELSA mid-century warming delta applied for the projection. Plants whose stated range falls outside both the current and projected zone end up dropped; the rest land in one of the three buckets below.
Currently suited · 4
These plants fit the ecoregion as it is today, but the mid-century projection moves them outside their stated zone range — plan for them to struggle by 2070.
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: