TheGuineo-Congolian region is abiogeographical region in Africa straddling theEquator and stretching from theAtlantic Ocean through theCongo Basin to theCongo / Nile divide inRwanda andBurundi.[1] Formerly, this region was largely covered inrain forest, on both well-drained sites and inswamp forests, but little undisturbed primary forest now remains, having been replaced in many areas bysavanna and secondary-growth forest.[2]
The Guineo-Congolian region is a tropical, lowland rain forest area, typified by the forests of theCongo Basin. The terrain is generally under 1,000 m (3,300 ft) and the annual rainfall is typically in the range 1,600 to 2,000 mm (63 to 79 in).[1] The forest is tall with a densecanopy, 30 m (100 ft) or more above the ground, with emergent trees up to 60 m (200 ft) tall, and with several layers. The constituent trees are mostlyevergreen or semi-evergreen, with a scattering of deciduous species. In the wetter areas, the trees may be clad with numerousepiphytes, but these are less common in drier areas. Large trees typical of these forests includeEntandrophragma spp.,Guarea cedrata,Guarea thompsonii,Lovoa trichilioides,Maranthes glabra,Parkia bicolor,Pericopsis elata andPetersianthus macrocarpus. Some parts of the forest are dominated by a single species, typically a member of theFabaceae, such asBrachystegia laurentii,Cynometra alexandri,Gilbertiodendron dewevrei,Julbernardia seretii orMichelsonia microphylla, which form extensivemonodominant stands.[2] In places in theIturi Rainforest of northeastern Democratic Republic of the Congo,G. dewevrei forms 90% of the tree species present in the canopy.[3]
The floras of the Guineo-Congolian region and the adjoiningZambezian Region are for the most part almost mutually exclusive, apart from a small number ofcosmopolitan species and a few others. However, there is a transition zone where the two floras, each in an impoverished form, intermingle or occur in a mosaic pattern, influenced by climatic factors andsoil types. This makes it difficult to define an exact boundary between the two regions.[4]
Several forest types can be distinguished. Hygrophilous coastal evergreen forests occur in moist locations between Sierra Leone and Gabon in an intermittent coastal strip; these forests are often rich in legume family species which may regenerate freely and form pure stands. Mixed moist semi-evergreen forests occur extensively, especially in the Congo Basin, in somewhat drier locations. Drier peripheral semi-evergreen forest border the mixed moist forests to north and south and are subject to fire damage from adjoiningsavanna regions. Monospecific forests occur as patches in evergreen or semi-evergreen forests in the Congo Basin.Gallery forests and swamp forests occur where conditions are suitable but have more open canopies. Short forest and scrub forest occur on rocky hills and areas with thin soils.[1]
.jpg)
TheKakamega forest in western Kenya is the most easterly remnant of the Guineo-Congolian rainforest system