Trees for Colobus Monkeys

Why Trees?

Colobus Monkeys, a unique group of primates, found in eastern and central Africa are also seen in the Usambara mountains of Tanzania which represent a mosaic of human habitat populating primary forests in the west Usambara hill ranges. Black-and-white colobuses are Old World monkeys of the genus Colobus, native to Africa. They are closely related to the red colobus monkeys of the genus Piliocolobus. Although Colobus monkeys are not endangered, they, however, face several challenges as their habitat is shrinking fast due to expanding farming on slopes of Tanzanian forests’ vast tracts which are not reserved and have traditional land rights. Further, local practices of the bushmeat trade, logging, and habitat destruction pose a serious threat to their survival in the long run.

They are listed as vulnerable by the IUCN, protected under Appendix II of CITES, and protected under Class A of the African convention. The population of this species is on the decline in its natural habitats and even in national parks estimated to have reduced by  30% in the last 30 years. As a result, the group is placed in the threatened category by IUCN in Togo, Benin, Nigeria, and Ghana. (Oates, et al., 2008).

Colobus monkeys are herbivorous and eat leaves, fruits, flowers, lichen, herbaceous plants, and bark. Their habitats include primary and secondary forests, riverine forests, and woodland grasslands; they are more frequently seen in logged forests than in other primary forests. Adapted to primary forests and farm-forest interface, Colobuses play a crucial role in the dispersal of seeds because of their sloppy eating habits and digestive systems.

Well-stocked vegetation in forests and tree canopy cover surrounding human habitation provides a conducing habitat for the group. Their presence in an area also signifies the state of forest cover in an area. According to Andrew Robert Marshall in the ‘Disturbance in the Udzungwa: Responses of Monkeys and Trees to Forest Degradation’, University of York, 2007, “Those areas in the Udzungwa lowlands that contain high densities and large groups of red and black and white colobus monkeys contain the best quality forest in terms of vegetation structure and composition."

The forest cover of the Usambara mountain range has degraded severely over the years due to honeycombing caused by extensive logging and firewood extraction, as woodfuel is the main source of domestic energy needs. At the same time, the diversity of species both flora and fauna, make it a  "biodiversity hotspot" to experts. There are reportedly more than 340 bird species and hundreds of plant species in the mountain range.  

In the West Usambara mountains, the colobuses are located in the Magamba Nature Reserve, Mkussu forest, Ndelemai Forest, Baga Forest, Mazumbai Forest, and small forests around the Usambara mountains. Promoting tree plantation can contribute to the regeneration of forests and the protection of biodiversity hotspots. 

Some of the main issues in the Usambara mountains include logging and habitat loss. Its lowland, coastal, and montane forests are all under threat due to nearby agricultural areas, fires, artisanal gold mining, illegal livestock grazing, and logging. Promoting tree plantation can contribute to the regenration of forests and the protection of biodiversity hotspots.

The majority of the human population in Tanzania is dependent on shifting cultivation and forest products such as poles, firewood, and charcoal. Due to the high electricity price, people depend heavily on firewood and charcoal for cooking. The Colobus Monkeys and other species continue to face a serious threat from tree cutting to meet this demand. Hence, planting trees is a crucial solution to address the challenges faced by them.

Tree Species

In this tree plantation initiative, species like Podo (Podocarpus usambarensis), Markhamia/Mile Tulip (Markhamia lutea), Crape jasmine (Tabernaemontana Spp.), African red stinkwood (Prunus Africana), Qunine tree (Rauvalfia caffra), Coast goldleaf (Bridelia micrantha), Large podded Albizia (Albizia schimperiana), Sudan teak (Cordia Africana), Water pear (Syzygium guineense), Peacock flower (Albizia gummifera) and Croton wood (Croton megalocarpus) are grown here.

Social Impact

The project aims to restore and improve the habitat of the threatened primate by way of improving tree cover on degraded forests and wastelands adjoining to forest reserves of West Usambara. The tree plantation while providing various goods and services critical for the local economy will also nurture the habitat of Colobus, both for its survival and proliferation.  It is a recognized fact that due to the paucity of resources, the Tanzania Forest Department is unable to take up tree plantation and habitat restoration which Grow-Trees.com aims to supplement by engaging the community. 

Planting trees will also help in conserving the degraded land in the Magamba Nature Forest of Gologolo. The reserve area is part of the West Usambara mountain ranges. The diverse altitudinal and climatic conditions prevalent in the area have led to a great biological diversity and richness of flora and fauna in the Magamba Nature Forest Reserve. The reserve is managed for the preservation of biodiversity, water resources, tourism, and scientific endeavors. The tree plantation will be essential in recovering the forests of the Usambara mountains, which provide Tanzania with a significant amount of water and energy.

The Usambara Mountains act as a key biodiversity area. To guarantee the sustainability of a vital water source, natural habitat restoration is essential. Reforestation will help to alleviate the consequences of climate change by preserving the topsoil, preventing erosion, and preserving the local water supply. In addition, it is important to protect biodiversity by preserving and expanding the rainforest's environment.

100,000 trees of different endemic species are planted, and the tree plantation is done by the villagers living close to the Magamba Nature Forest to give them a sense of ownership over the forest's protection and help them with temporary employment. Additionally, this initiative aims to provide locals with learning opportunities that will enable them to understand how environmentally sound conservation practices improve crop fertility, increase the supply of forest products, and lessen reliance on the Magamba Nature Reserve for forest resources.