Tanzania: East Usambara Mountains



The East Usambara Mountains are located near the northeast coast of Tanzania in Tanga region. The East Usambaras are part of the Eastern Arc mountain range that extends from Southern Kenya across the Eastern part of Tanzania. The Eastern Arc is a globally recognized biodiversity hotspot which has the highest ration of endemic flora and fauna per 100 km2 out of all of the biodiversity hotspots in the world. The East Usambara landscape represents a mosaic of submontane and lowland forests, tree and cash crop plantations, agroforestry systems and agricultural land. Most of the remaining forests are fragmented with the biggest blocks found within forest reserves and the Amani and Nilo Nature Reserves. The agricultural land use consists of large commercial plantations of cash crops such as tea in the highlands and sisal in the lowlands and smallholder agriculture. Common cash crops cultivated by small-holders include spices such cardamom, clove and black pepper, typically grown in agroforestry systems. Sugar cane is growing in importance in the highlands. Maize, beans, cassava and yams are commonly cultivated for subsistence. The Landscape Mosaics Project has mainly worked in three village landscapes in the East Usambaras, two in the highland and one in the lowland zone.


The area is home to the Shambaa ethnic group who are considered among the long-term inhabitants of the area. Other large ethnic groups inhabiting the mountains and surrounding lowlands include Zigua, Bondei and Pare. Yet, the boundaries between the different ethnic groups are not solid. During the past decades, people from other parts of Tanzania and many ethnic groups have migrated to the region, attracted by the favorable climatic conditions for agriculture and job opportunities in the tea plantations.


In the East Usambaras, more than 100 species of plants and animals are endemic or near-endemic to the forests of the Eastern Arcs, some confined to particular altitudinal bands. In the East Usambara mountains’ forests, 7 species of endemic vertebrates are found, and additional 28 species are confined to the Eastern Arc or East Usambara lowland forests. 40 species of trees found in the East Usambaras are endemic or near-endemic to the Eastern Arc. High rates of endemism are also observed in invertebrate groups as well as shrubs and herbs, such as the African violet (Saintpaulia sp.).

Endemic species richness is highest in the montane and submontane forests that blend into the lowland forests on the eastern side of the mountains. The lowland forests are considered part of a globally important ecoregion, the Eastern African coastal forests.
The main direct threat to the East Usambara’s valuable biodiversity is the conversion of forests and tree dominated landscape into open habitats for agricultural use. Fires that spread from surrounding fields in the low lands, illegal logging and small scale mining are also considered threats. Underlying these direct threats, there are several political economic factors, such as governance weaknesses and problems in land tenure.


The Landscape Mosaics Project is implemented in the East Usambaras site by Tanzania Forest Conservation Group (TFCG) and the CIFOR-ICRAF Biodiversity Platform in collaboration with the TFCG-WWF East Usambara Forest Landscape Restoration Project.


Heini Vihemaki, Site Leader (ICRAF)

Emmanuel Lyimo, Research Officer (TFCG)

Nike Doggart, Scientific Advisor (TFCG)  


For more information on the site, please contact Heini Vihemaki, Site Leader (ICRAF) on h.vihemaki@cgiar.org or Nike Doggart  on ndoggart@tfcg.or.tz.


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