The site, also known as ‘the Eritrean Green Belt’ (or by the Italian name ‘Pendice Orientale’), lies between about 20 and 100 km north of Asmara on the coastal (eastern) escarpment of the Central Plateau. It contains the only remaining mixed evergreen tropical woodland in Eritrea. There is magnificent mountain scenery with sheer drops, rock precipices, spurs and deep valleys cutting into the mountains up to high altitudes. The whole montane area is frequently in cloud and there are profuse lichens in some areas. The highest upland areas consist of rough, stony moorland, rocky hillsides and peaks, scrubby tussock-grassland (with exotic cacti including Opuntia vulgaris), and Juniperus procera woodland. Riparian vegetation includes willows in the deep valleys. Below about 2,500 m, Juniperus procera woodland with shrubby undergrowth dominates. Below c.2,100–2,300 m the vegetation is Olea africana-dominated evergreen woodland and upland scrub (Olea, Euphorbia, Dodonaea, Opuntia, Rosa and occasional Acacia spp.), which gives way, at around 1,400 m, to Combretum forest, with Terminalia and Anogeissus spp. This continues down to c.300 m at the edge of the Eastern Plain. Riparian woodland along watercourses in this zone includes Acacia, Ficus, Rhus, Acokanthera, Ricinus, Gymnosporia and Buddleia spp., with dense mats of the herb Flaveria australasiatica adjacent to rivers at intermediate altitudes after rain.Because of the huge altitudinal gradient (from 2,600 m at the top of the massif, dropping to about 400 m over a horizontal distance of less than 15 km), the site contains a great diversity of climates and habitats. For five months of the year (October to March) the upper slopes can be covered continuously in mist and drizzle. It tends to be drier and sunnier from March to September, but the site can also receive rainfall during the ‘main rains’ sweeping down from the plateau between mid-June and mid-September. There are areas of poor agricultural land among the moorland, scrub and juniper, with rocky pastureland and terraced fields where wheat, barley and taff (Eragrostis tef) are cultivated during the wetter months (about 10% of the land appeared cultivated in one area at about 2,100 m: Butynski 1995). There are scattered Eucalyptus plantations and, at lower levels (in the Olea africana-dominated woodland), some cultivation of maize, potatoes, tomatoes, peppers, citrus fruits and coffee. There is also some (probably seasonal) grazing of livestock, particularly at higher levels on the plateau and during the wetter months.
See Box and Table 2 for key species. The site qualifies as an IBA partly due to the presence of significant numbers of Falco naumanni. Although he did not visit Semenawi Bahri specifically, Smith reports this species, in the 1950s, as ‘abundant at all altitudes on open grassland and scrub’ and also Circus macrourus as ‘a regular wintering species on the plateau over the moors’ (together with F. tinnunculus). More recently (1995) ‘impressive numbers’ of F. naumanni were recorded near an agricultural scheme by Tom Butynski, walking west from Allet (i.e. close to the proposed area of this IBA), although no information on actual numbers is available. It also seems likely that Rougetius rougetii will be found to occur here, as this species was said by Smith to ‘characterize small upland streams with adjacent willows, rank grass and marshy vegetation, 6,000 feet [1,800 m] and over’.This is the only IBA in Eritrea from which the Afrotropical Highland (A07) species Caprimulgus poliocephalus is recorded and it appears particularly important for Francolinus erckelii, with ‘hundreds’ of calling birds recorded over several days throughout the site between 900–2,500 m in 1995. It is one of only two IBAs in the country from which the Somali–Masai (A08) species Cisticola bodessa is recorded. A number of the Afrotropical Highland species are included in Table 2 on the basis that they appear very likely to occur from comments in the literature by Smith which do not mention the location by name, but indicate that the species occurs in habitats and at altitudes on the eastern escarpment which correspond with those occurring within the site. Given the almost complete lack of survey work at the site it seems certain that additional species of both biomes will be added to these lists very readily through future surveys. There are also records of three Sahel (A03) biome species; see Table 2.The site is also clearly important for raptors, including migrants, and is one of a number of sites along the eastern escarpment of the highland plateau which need further investigation as possible migration bottleneck sites (see ‘Overview of the inventory’). It is also important for other Palearctic migrants (e.g. Phoenicurus phoenicurus), particularly as it is one of the last wooded areas where forest migrants can rest and feed before continuing north to Europe or Asia. As such it is likely to be an important wintering and/ or staging area for Coturnix coturnix, Phylloscopus collybita and others, particularly warblers. The complete absence of some expected African bird families and insect groups was noticed with some surprise by Butynski (during March, in wet conditions). However, this may well reflect the large climatic changes in the site at different times of year and underlines the need for more survey work at different altitudes and in different seasons.
Non-bird biodiversity: The Semenawi Bahri is said to contain populations of Tragelaphus strepsiceros (LR/cd), T. scripta (LR/nt), Oreotragus oreotragus (LR/cd) and a species of Cephalophus duiker. Particularly high densities of baboons Papio hamadryas (LR/nt) were found in this area (and at sites ER006, ER007 and ER008) in 1997/98 (Zinner et al. 1999). Due to the diversity of altitudes, climates and habitats, it is probably one of the areas of highest species diversity in Eritrea and is known to contain species with small range distributions in Eritrea and some at the northern limit of their distributional range.
Pressure/threats to key biodiversity
The site currently has no formal protected-area status, but it is proposed as one of a suite of possible new protected areas (National Parks) in the National Environmental Management Plan for Eritrea (EAE 1995, DOE 1999). This Park may extend to include other parts of the escarpment slopes with similar, linked habitat (e.g. ER006, ER007 and ER008). The site is only a one-hour drive from Asmara and has considerable potential for specialized (birdwatching) tourism, particularly at times of year (probably September–October and March–April) when there are likely to be large numbers of migrants using or passing over the site. Some areas of forest within the site are quite degraded from decades of cultivation and grazing, particularly at higher altitudes (especially above 1,500 m). There are also impacts from the years of war with bunkers, placements, graves and piles of spent cartridges in places. At higher altitudes there are quite extensive areas of exotic non-native vegetation (Opuntia vulgaris and Eucalyptus plantations). In the late 1980s, a system of ‘closures’ of wooded hillsides and juniper forest was introduced, operated by local village councils (‘baitos’) in partnership with government. Such areas are closed to access for tree-cutting, grazing or agriculture for a number of years to allow forest regeneration (including some tree-planting) and to stabilize slopes. After 5–10 years, these areas are reopened and new closures established in other areas. In total about 100,000 ha have been closed in Semenawi and Debubawi Bahri regions. It is believed that populations of Panthera pardus, Tragelaphus strepsiceros, T. scriptus, Papio hamadryas and Oreotragus oreotragus are increasing as a result of this system of forest closures.
BirdLife International (2020) Important Bird Areas factsheet: Semenawi Bahri. Downloaded from
http://www.birdlife.org on 13/08/2020.