Coniferous

Montane vegetation of the Imatong and Dongotona ranges

Both ranges are located in Equatoria Province, the highest one culminating at 3 187 m. The lower slopes of these mountains, below about 1 500 meters, have vegetation in wetter areas similar to that of the derived woodland savanna, but with fewer species. In drier areas they are similar to low rainfall woodland savanna, especially on rocky hill slopes, with an abundance of Boswellia papyrifera and Terminalia brownii. Between 1 500 and 2 600 meters the climax vegetation is closed evergreen forest with Podocarpus milanjianus, Olea hochstetteri and Syzygium spp. dominant over a shrubby understorey. Second growth of Acacia xiphocarpa occupies large areas on old cultivation sites. Between 2 600 and 3 000 meters, Podocarpus milanjianus again forms the climax vegetation, but is less mixed with other species, apart from a little Olea hochstetteri. This zone includes large areas of mountain meadow dominated by the sedge Bulbostyles atrosanguineus. The bamboo Arundinaria alpina is also found. Much of the ground is wet or swampy because of the combination of high rainfall and low potential evapo-transpiration. Above 3 000 meters, ferns (Erica arborea and Myrica salicifolia) are dominant. Many species of herbs occur.

Montane vegetation of the Didinga range

This range lies also in Equatoria Province. The highest point, 2 963 m high, is Mount Lotuke at the south end, the summit carrying vegetation similar to that of the Imatong, with Podocarpus milanjianus mixed forest. Below this zone there is, however, a belt with a few relic trees of Juniperus procera, probably the remnants of a forest now destroyed by fire. The north end of the Didinga Mountains is a high plateau, in which trees of Podocarpus milanjianus occur in dense thickets of Olea chrysophylla, Soutia myrtina and other species. Dense forests of Podocarpus and Albizia maranguensis are confined to valleys.

Montane vegetation of the Red Sea hills

Up to 2 260 m high, these hills are situated in the north-eastern edge of the Sudan. The seaward facing slopes of the hills have a winter rainfall, while those not facing the sea have a very low summer rainfall. Mist and clouds have an important effect on the vegetation. A few localities enjoy both summer and winter rains. Near the Eritrean border, forests of Juniperus procera are found, with a few well-stocked areas but most ravaged by fire and overgrazing. Associated with Juniperus is Olea chrysophylla. Characteristic plants of the drier parts of this range include Dracaena ombet and Euphorbia abyssinica.

last updated: Wednesday, September 27, 2006