The East Usambara Mountains are almost entirely within Muheza District in Tanga region, apart from some smaller parts in the west that fall in Korogwe and Mkinga (Nilo) Districts. The mountains rise to an altitude of 1,506 m at Mt Nilo. The population is 101,767 people distributed across 61 villages in the areas. Outside of reserves most of the forest has been cleared for farmland, apart from in the Derema proposed Forest Reserve and some other areas proposed as Village Forest Reserves. Some forest also remains in private land – for example in the lowland Kwamtili estate.
In Muheza District the East Usambaras contain two Nature Reserves (Amani and Nilo), 12 Forest Reserves (Bamba, Derema, Kambai, Kwamgumi, Segoma, Semdoe, Mtai, Mlinga, Manga, Mlungui, Longuza Teak plantation), four Village Forest Reserves (Kizee, Kizangata, Mfundia, Handei), and two private forests (Magoroto and Kwamtili). The total area is around 31,000 ha. Most of the Nilo Nature Reserve and a part of Amani Nature Reserve fall within Korogwe and Mkinga (Nilo) Districts, but the only EastUsambara reserve that wholly falls within Korogwe is Bombo West with a total area of 3,523 ha.
The forests of the East Usambara Mountains range from lowland areas at c.300 m on the east side, through sub-montane forests to the montane forests of Nilo. Tree species composition of these forests varies considerably, but species such as Khaya anthotheca, Milicia excelsa are found in the lowlands and others such as Myrianthus holstii, Albizia gummifera, Allanblackia stuhlmannii and Newtonia buchananii dominate at higher altitudes.
The mountain forests contain at least 7 strict endemic vertebrates and a further 28 species that are confined to the Eastern Arc or East Usambara lowland forests
The East Usambara forests are globally recognised for their exceptional biodiversity importance. The mountain forests contain at least 7 strict endemic vertebrates and a further 28 species that are confined to the Eastern Arc or East Usambara lowland forests. There are also 40 Eastern Arc endemic trees. Similar high rates of endemism are also seen in invertebrate animals and plants such as shrubs and herbs. The montane forests grade into lowland forests on the eastern margin of the mountain, and these lowland forests also have exceptional biological importance.
…expansion of farmland, logging, gold mining and invasive species.
The major threats to the forests in the East Usambaras are fire spreading from surrounding farmlands, logging, gold mining and farmland encroachment (especially into ungazetted forests). There is also a serious issue of invasive species, for example of the tree Maesopsis and various shrubs, herbs and lianas.