This mountain block is found within Kilosa District of Morogoro region. It is an elongate ridge extending up to 2,250 m altitude. The human population surrounding the forest is at least 75,720 people and land outside the reserves is generally farmland.
The Ukaguru Mountain range contains 6 catchments Forest Reserves containing Eastern Arc forest habitat (Ikwamba, Mamboto, Mamboya, Mamiwa Kisara North, Mamiwa Kisara South, Uponera). These total 18,168 ha. There is also a large softwood plantation in the mountains that occupies an additional 3,600 ha. The main Ukaguru ridge is largely covered by forest with moist forests on the wetter eastern side. Heath lands occur on the summits with upper montane forest. Montane forest and dry submontane forest occurs on the lower slopes.
The drier south south west slopes of the whole ridge are covered by dry evergreen forests, bushes and wooded grasslands. Where forest edges are bordered by grassland, they are maintained by fire.
In terms of biodiversity the Ukaguru forests support one strictly endemic animal and a further nine Eastern Arc endemics. For trees there are at least four Eastern Arc endemic species. Two other strict endemic amphibians will be described. Some of the forests of this range, in particular those of Mamiwa-Kisara South are biologically unexplored and might support additional species of interest.
Threats to this forest include encroachment from farmers and workers from the plantation forest, fuel wood collection and fires spreading from lowland areas. Variation orders for Mamiwa-Kisara North and Mamiwa-Kisara South, expanding the forest area, have never been completed legally.