Broadleaved forests

The closed forest types are found in the mountain ranges and in the derived woodland savannas. Their only common features are their closed canopy and multi-storeyed structure that differentiate them from the vegetation of the surrounding areas.

Tropical rain and gallery forests

Tropical rain forest is confined to a few small, scattered localities. Talanga, Lotti and Laboni forests are at the base of the Imatong Mountains; Azza forest is in Meridi district and there are other small areas on the Aloma Plateau and in the Yambio area. In these forests, four storeys can be distinguished in the vegetation:

  • The canopy trees, which are 30 to 50 meters high with long, straight trunks, often buttressed at the base;

  • The second-storey trees, from 15 to 30 meters high, usually not so straight, more copiously branched and with less tendency to form buttresses;

  • The shrub layer, 4 to 6 meters high, often very dense, with numerous creepers and lianas; and

  • The ground layer of herbs and grasses, usually sparse and often absent.

The species occurring in rain forest are similar to those of the drier parts of the forests of West Africa. The most common species are Chrysophyllum albidum and Celtis zenkeri, with Holoptelea grandis in Azza forest. A number of valuable timber trees are found, including Khaya grandifoliola, Chlorophora excelsa, Entrandrophragma angolense and others.

Gallery forest may be regarded as a reduced type of rain forest confined to the banks of streams. It is generally found in rather deep U-shaped valleys, and benefits both from the extra water supply of the streams and the protection against fire afforded by the steeply sloping banks. Other important species are Cola cordifolia, Syzygium guineense and, especially in swampy places, Mitragyna stipulosa.

Acacia nilotica forests

These forests occur along the Nile from the Egyptian frontier south as far as Jebelein on the White Nile and Roseires on the Blue Nile. They occur on land that is more or less flooded when the river rises. Acacia nilotica is the dominant species, and occurs over large areas as pure dense stands. In the shallower, less frequently flooded basins along the Atbara River and in some inland sites, they are replaced by Hyphaene thebaica palm forests.

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last updated: Monday, January 12, 2004