Dessa’a forest is on the eastern escarpment, north-east of Mekele and c.20 km south-east of Agula town, Eastern Zone. The topography in Dessa’a is varied and includes some flatter areas and gentle slopes as well as steep scarps. The forest extends in an easterly direction along and down the escarpment, and forms a climatic buffer zone between the cool highlands of Tigray and the hot lowlands in Afar Region. Generally, rainfall along this part of the escarpment is marginal for tree growth. However, it seems likely that the forest abstracts moisture from the clouds that build up along the escarpment. Close to the forest there is a valley where one of the oldest irrigation systems in the country still functions. The soils in the valley are deep and fertile with both grassy and somewhat swampy patches as well as cultivated fields. Most of the trees in the forest are found at the higher altitudes, and relatively undisturbed forest exists only on the steep eastern slopes. A detailed study of the vegetation has not been made, but the species composition is most likely similar to that of the escarpment forests in Eritrea. The dominant tree species is Juniperus procera, with some patches of Olea europaea cuspidata; at lower altitudes Juniperus procera tends to be replaced by Acacia spp. including A. origena, a species only found on the eastern escarpment of Ethiopia and Eritrea, and in Yemen. A range of small understorey trees and bushes are likely to occur. Particularly characteristic of such dry montane forests are Barbeya oleoides (a monotypic family), Cadia purpurea, Berberis holstii and Tarchonanthus camphoratus. The plateau above the escarpment is heavily cultivated and the forest provides valuable grazing, particularly in the dry season. A major feature of the forest is the centuries-old track that passes through it, used by camel trains bringing blocks of salt up from the Afar.
See Box and Table 3 for key species. This is the only known location in Ethiopia for Emberiza cineracea, whose range within Africa otherwise extends only to Eritrea. However, the species is known only from one record of a single bird. Circus macrourus has also been recorded. A total of 42 bird species have been recorded from the forest and 67 from the plateau directly west of the forest. The combined total includes 15 species belonging to the Afrotropical Highlands biome of which one, Serinus nigriceps, is an Ethiopian endemic near the edge of its range. Below 1,800 m, two Somali–Masai biome species occur, namely Tockus flavirostris and Uraeginthus ianthinogaster. The eastern escarpment in this area is a distinct flyway for migrating eagles, with up to 50 Aquila nipalensis recorded on one day in October 1995.
Non-bird biodiversity: None known to BirdLife International.
Pressure/threats to key biodiversity
It appears that there is currently no natural forest regeneration. Grazing by domestic animals is given as a main cause for this, but the area is now very dry and climatic changes should not be ruled out. Many of the trees are old, and many of those at the top of the forest next to the plateau support a heavy growth of a dwarf mistletoe, Arceuthobium juniperi-procerae. A big fire in 1969 destroyed a large part of the forest. The areas most seriously affected were colonized by evergreen bushland species, particularly Dodonea angustifolia and Euclea spp. However, recent reports suggest that there is some forest regeneration in these areas. A survey in 1992 found that c.30% of the area was still forested. The plateau is heavily farmed and the traditional irrigation system has been somewhat damaged. It should be studied and repaired before irreparable damage occurs. It would be beneficial to integrate both the plateau and the Dessa’a forest in any conservation-oriented activities.
BirdLife International (2022) Important Bird Areas factsheet: Dessa'a forest. Downloaded from
http://www.birdlife.org on 23/05/2022.