Closed forest are mainly found in the highlands, the escarpments and in some spots along rivers such as Gash, Bark and Anseba. The main species found in highlands is Olea africana which frequently occurs mixed with Juniperus procera, at the higher elevations or, at lower altitudes, it forms mixed forest formations with other species such as Celtis africana, Carissa edulis, Teclea nobilis, Anogeissus leicarpus, Dodonaea angustifolia, Combretum molle, Acacia etbaica, Terminalia brownii and a number of Acacia sp. Palm forests mainly composed by (Hyphaene thebaica) are found along rivers throughout the cost and along the river system in western lowland.
Mangroves are found scattered along the coast but mainly along the southern and central coastal zones. They are composed essentially of Rhizophora mucronata and Avicennia marina.
The higher altitudes of the highlands have been colonized by Juniperus procera forming pure stands and, as soon as the altitude decreases, this species mixes with broadleaved ones, mainly with Olea africana. The Juniperus procera is now found in five main locations namely Soyra Mountain, in the southern border with Ethiopia, Abahanni Mountain, Green Belt near Asmara, Rora Habab and in Om Hagar plateau near the border with Soudan in the north.