I - ECOLOGY

This area has high levels of precipitation and is covered in forest and savannahs, most of which secondary regrowth, the product of the degradation of the original forest. Three factors condition the emergence of different types of forests : land features, soil composition, and rainfall. The latter seems most significant in the geographical distribution of present types of vegetation. The following are the different types of forests that have been identified (see map 1).

1 - Evergreen forests of Gilbertiodendron dewevrei and Scorodophloeus senkeri on highland in areas with high levels of rainfall (over 1 600 mm/year).

2 - Periodically flooded and swamp forests, at the bottom and on the edges of the Basin.

3 - Guinean semideciduous forest, covering most of the area.

4 - Peri-Guinean semideciduous forest in a landscape dominated by grassland.

5 - Forests of semitropical semicaducous foliage in the south of Zaïre.

6 - Sclerophyllous forests of trees with fleshy foliage in dry montane and sub-montane areas (rainfall : less than 1 m/year).

7 - Montane rainforest of Dracaena, Ekebergia, Ficalhoa, Podocarpus (on the slopes of the Ruwenzori and Virunga).

8 - Secondary forests of Musanga due to deforestation.

9 - Woodland of Isoberlinia doka (in the north) and of Brachystegia (in the south) (rainfall : 1 100 to 1 500 mm/year).

An extremely rich and varied flora and fauna can be found in the rainforest environment. On the whole of the territory of Zaïre, about 40 000 different plant species have been inventoried, 3 000 of which are endemic ; there are 409 species of mammals and 1086 bird species.

Agriculture occupies nearly 3 % of a country's total area, and forest fallow 8 %. Forest exploitation represents approximrately 500 000 m³/year, but affects 25 % of rainforest areas[57].

Legends : 1 - Flooded and swamp forest. 2 - Mosaic of flooded and highland forests. 3 - Evergreen rainforest. 4 - Rainforest of semicaducous foliage. 5 - Dry and Zambezian woodland. 6 - Afro-Alpine area : sub-montane and montane forest ; Afro-sub-alpine and afro-alpine thickets and grassland (on Mount Cameroon). 7 - Transitional evergreen forest evolving towards a form of semicaducous vegetation. 8 - Shrubland or wooded savanna and steppes. 9 - Mosaic of forest and savanna. 10 - Mosaic of forest, savanna, Zambezian dry forest. 11 - Woodland with Marantacea undergrowth. 12 - Mangroves and coastal flooded forest.

[57] IUCN, 1981, 1991, 1992