The Eastern Arc: Legacy of a 30m yrs old mountain range

09Mar 2016
Our Reporter
The Guardian
The Eastern Arc: Legacy of a 30m yrs old mountain range

As a child, my father took me to visit his homeland in north east Tanzania in the district of Korogwe, Tanga Region.

He cautioned me that the village was perched high up on some steep mountain side but assured me of breathe taking scenery.

I didn’t want to forego the comforts of city amenities but the budding aspiring artist that I was, I reluctantly agreed.

When we got there, he was right about both things, the village was perched high up on the Usambara Mountains, the home of the Wasambaa, my father’s and my tribe.

The road to the village was treacherous and as far as I was concerned, that dirt tract did not merit being christened a road.

The car drove right on the edge of a steep cliff and dad warned me not to look down, but every now and then when someone exclaimed curiosity caught the better of me and I stole a look.

The height was shocking, the closeness to the edge sent a chill up my spine to the nape of my neck and creaking of the old land rover kept my hair on edge.

We were climbing the Eastern Arc, a chain of ancient mountains covered by rainforests and grasslands that stretches through northeast Tanzania and into southwest Kenya.

When we got to Welei, a village of a few hundred people and the land of my forefathers, I heaved a sigh of relief to step on flat land again.

Whe I turned around to see where we had come from, my heart skipped a beat and I held my breathe, dad was right, the scene was indeed breathe taking.

For the following week as I explored the sides of the mountains with my cousins who were raised there, I came to fell in love with the mountains, their waterfalls, and forests, the frogs and butterflies in the forest, drinking from natural springs and swimming in ponds clearer than the pool at our town apartments.

Little did I know, I was walking on ground some 2 billion years old! Neighbouring mountains like Kilimanjaro are only about 2 million years old.

The mountain range was formed nearly two billion years ago. Due to a lack of glaciations and a relatively consistent climate, the rainforest has gone through a long term and unique evolution resulting in an impressive amount of endemism and an old growth cloud rainforests - "Eastern Arc moist forest flora".

Biogeography and Ecology of the Rain Forests of Eastern Africa by Lovett, J.C. UK Cambridge University Press (1993).

Even the mountain range forest of the 2bn years old Usambara Mountains has survived for over 30 million years and was once connected to the forests of the Congo Basin and all the way to West Africa.

Learn about these ancient mountains, what they are, what they offer, the dangers facing them and what is being done to preserve them.

The Eastern Arc Mountains

The Eastern Arc Mountains in Tanzania and Kenya are among the most important areas for the conservation of biological diversity in the world.

The conservation of these mountains is being supported by the Eastern Arc Mountains Conservation Endowment Fund in collaboration with the Government of Tanzania and various development partners including the Government of Norway and GEF/UNDP.

Location (in Tanzania)

The Eastern Arc is made up of several mountains ranges that stretch across 15 districts in Tanzania:
• North/South Pare
• West/East Usambara
• Nguu
• Nguru
• Uluguru
• Ukaguru
• Rubeho
• Malundwe
• Udzungwa
• Mahenge

Districts of the Eastern Arc Mountains of Tanzania
• Mwanga and Same
• Lushoto, Korogwe, Muheza, Mkinga
• Kilindi
• Mvomero
• Morogoro and Mvomero
• Kilosa
• Mpwapwa and Kilosa
• Morogoro
• Kilombero, Kilolo and Mufindi
• Ulanga


Many thousands of species of plants and animals are found in these forests and nowhere else on earth.

This includes at least 100 species of birds, mammals, amphibians and reptiles; at least 500 plants and huge numbers of smaller creatures including butterflies and millipedes.

Many of these species are threatened with extinction.

The Eastern Arc is recognised internationally as an area with an exceptional concentration of species that occur nowhere else on earth.

Economic Value

The Eastern Arc supplies many resources and environmental services for the people of Tanzania. The total economic value of these resources has been estimated as at least $620 million.


Agriculture, industry and domestic users depend on the Eastern Arc for their water supply.

The Eastern Arc Mountains are the catchment areas for many of the important rivers of eastern Tanzania.

The Ruvu River that supplies water to Morogoro, Coast and Dar es Salaam flows from the Uluguru Mountains; the Sigi river that supplies water to Tanga flows from the East Usambara Mountains.

Morogoro and Iringa receive most of their water from the Eastern Arc Mountains. The Wami, Kilombero, Little Ruaha and Pangani Rivers also flow from different ranges within the Eastern Arc Mountains and have enormous benefits for rural people and agricultural schemes in the lowlands.

At least 25% of Tanzanians depend on the Eastern Arc Mountains for their water supply, and without this the economic future of the country would be in doubt.


Hydroelectric power using water from the Eastern Arc Forests contributes more than 50% of the electricity in Tanzania.

This power is essential to economic growth and development of the country.

A reliable source of water is crucial to avoid serious power blackouts and shortages, with the major inevitable economic consequences.


The cool and reliable climate in the Eastern Arc allows the cultivation of many food and cash crops, which feed local populations and are exported to towns and cities.

Fruits and vegetables exported to Dar es Salaam and other large cities include bananas, apples, pears, peaches, plums, cabbages, potatoes, peas, and other specialist items such as leeks, celery, parsley and strawberries.

Food grown in the Eastern Arc and exported to towns makes a major contribution to feeding the people of Tanzania and reducing poverty.

Due to fertile soils and sufficient rainfall the Eastern Arc Mountains area is famous for large scale farming of Cash Crops, e.g. Coffee, Tea and Sugarcane estates (Kilombero and Mtibwa Sugar Estates).


The forests and mountains of the Eastern Arc provide an attraction to visiting tourists.

Current tourist locations include the South Pare Mountains, Udzungwa Mountains National Park, Amani Nature Reserve in the East Usambaras, Lushoto in the West Usambaras and the area above Morogoro in the Uluguru Mountains.

The Eastern Arc is increasingly becoming popular with tourists particularly those with specialist interests in birds and wildlife.

The area also offers an unparalleled wilderness experience for the more adventurous visitors.

Eastern Arc Forest Conservation

Estimates suggest that more than 70% of the original forest cover has been destroyed and only about 5,400 sq km of forest remain on the mountains.

Most of the forest has been lost in the past 100 years due to conversion to farmland, unsustainable timber harvesting and uncontrolled fires.

Conserving these forest habitats is very important for the global community and for the people of Tanzania.

Most of the remaining forests are within government forest reserves. These government forest reserves are poorly funded and have few staff, however they provide the mainstay for conservation in the area.

Since 1998 local people often supported by civil society organisations have been increasingly involved in the management of the Eastern Arc Forests. This reflects a change in forest management policy in Tanzania.

e Eastern Arc Mountains Conservation Endowment Fund (EAMCEF) is a Trust Fund that was established and functions as a long-term and reliable funding mechanism to support Community Development, Biodiversity Conservation and Applied Research Projects, which promote the biological diversity, ecological functions and sustainable use of natural resources in the Eastern Arc Mountains of Tanzania.

The Eastern Arc Mountains Conservation Endowment Fund

EAMCEF was officially registered in Tanzania on 6th June 2001, under the Trustees’ Incorporation Act of the Laws of Tanzania.

It was originally conceived as a joint initiative of the Government of the United Republic of Tanzania, the Board of Trustees (BOT), the World Bank (WB) and the Global Environment Facility (GEF).

The Trust Fund operates as a Not-for-Profit Non-Governmental Organization (NGO). Initially, EAMCEF operated as a component of the WB financed project (TFCMP) under the Ministry of Natural Resources and Tourism (MNRT) whereby a total of US$ 2.4 Mil.

credit facility was used to finance activities and operations of its 7 years first phase (2002-2009), the establishment phase.

Funding of the second phase (the permanent phase) was initially planned to come mainly from incomes generated from the investment of the endowment capital secured from the GEF commitment of US$ 7.0 mil. as well as additional resources acquired from other sources through fundraising activities.

The fund is governed by a Board of Trustee EAMCEF operates as a Trust Fund Organization and managed by an Endowment Fund Secretariat based in its own office complex in Morogoro and headed by an Executive Director.

The main intention of establishing the Trust Fund is to address the need for a long-term sustainable approach to funding the conservation of forest biodiversity in the important ecosystem.

Unlike the time limited projects, EAMCEF was established and will continue to operate as a long-term institution.

Inadequate and poorly targeted public and donor resources for forest biodiversity in the Eastern Arc has meant that there has been a limited view of long-term resource requirements and financing needs.