[3][4] The Rumpi hills are covered by more than 2,300 km2 (890 sq mi) of a combination of mid-elevation montane, coastal evergreen, and drier northern semi-evergreen forests as well as other vegetation types.

Located in the equatorial forest zone of Cameroon, this area is very rich in plant biodiversity ranging from fungi to angiosperms.

This variation in the distribution of forest ecosystems, is due to the changing agricultural landscape especially along the southern slopes of these hills.

These lowland forests are situated in the Lower Guinea zone of the Guineo-Congolian region of rich and endemic biodiversity composed of animal and plant species.

Most common plant families (with regards to species density and distribution) are Annonaceae, Leguminosae, Euphorbiaceae and Rubiaceae.

Over the years, the weathering of these basement rocks has created dense layers of leached and poor red earth soils.

Meanwhile, along the Atlantic Equatorial coastal forests, the continuous deposition of sand, rocks and silt has created extensive muddy banks, mangrove swamps and sandy beaches.