Albertine Rift montane forests

• Category: Forest Biomes
• Geographic Location: Africa
• Summary: Remote and rugged, the Albertine Rift spans a wide range of habitats, from rainforest to glaciers, active volcanoes to deep lakes; the montane forests here are very rich in biodiversity.

The Albertine Rift covers more than 115,831 square miles (300,000 square kilometers) in central east Africa. This area is one of the most species-rich regions in Africa and also one of the most scenic, including the Ruwenzori Mountains, the Virunga Mountain volcanoes, and the Semliki Valley. The Albertine Rift is also one of Africa's most biodiversity-rich—and threatened—ecosystems. There is no clear-cut definition of the Albertine Rift, but the area it covers begins north of Lake Albert between Arua and Pakwach (West Nile, Uganda) and extends southward, following the course of the Rift Valley to the Lendu Plateau and the lower reaches of the Kibali and Ituri Rivers. It includes the forests of western Uganda and Kigezi (Uganda), north and south Kivu in the Democratic Republic of Congo, parts of western Rwanda and Burundi, Itombwe to Marungu in western Katanga in the Democratic Republic of Congo, areas of western Tanzania, and part of northwestern Zambia.

The Albertine Rift has been marked by political turmoil that has included massive displacement of peoples. Habitat destruction and other issues, such as the bushmeat trade, are very real and direct threats to species in the region. The Albertine Rift also has one of the highest population-growth trends in eastern and central Africa. Most of the population of this area is largely engaged in rural subsistence agriculture. One of the most threatened and famous animals on the planet, the mountain gorilla, lives within the Albertine Rift on the slopes of the Virunga volcanoes, which are among the steepest in Africa. However, after a period of mountain gorilla population decline, the twenty-first century saw a rebound due to conservationist efforts in the region. From the late 1970s to the 2020s, the population increased from around 230 mountain gorillas to between seven hundred and one thousand gorillas (estimates and researchers vary on the exact number).

The Virunga volcanic range, like the Albertine as a whole, is in the westernmost part of the immense East Africa Rift Valley system that cuts down across the continent from the Horn of Africa at the juncture of the Red Sea and the Gulf of Aden. Due to volcanic activity and the sinking and rising of parts of the continental plate, diverse and dramatic landscapes have formed. The flanks of the mountains and volcanoes of the Albertine Rift are covered with distinctive bands of vegetation that change higher up the slopes. At lower altitudes is dense forest, with montane forest typically occurring above this zone, where the trees are covered with moss and ferns. Above the montane forest is a zone of giant bamboo, followed by moorland and rock and/or ice, depending on the height of the mountain.

Plant and Animal Life

The levels of endemism (evolving uniquely to fit an isolated biome) among species is very high in the Albertine Rift for all living organisms: plants, invertebrates, birds, and mammals. A total of thirteen species of dragonflies and damselflies are unique to the Albertine Rift, for example, and some 117 butterfly species have been described as being endemic to the area. The forests of the Albertine Rift are mostly unexplored when it comes to invertebrates. Bwindi Impenetrable Forest in Uganda alone has five species of stingless bees. Many more species of invertebrates await discovery and formal description by scientists.

Bird life is abundant in the region, and the forests are home to a large number of endemic and near-endemic species. A total of forty-one species of birds are endemic to the Albertine Rift, including the Rwenzori Turaco, Albertine Owlet, Congo Bay Owl, Red-throated Alethe, and Rockefeller's Sunbird.

Some thirty-four species of endemic mammals live in the Albertine Rift; most are small mammals such as shrews, rats, and bats. A few of the larger ones include the Rwenzori duiker, which lives at high altitudes in the Rwenzori massif, and the striking golden monkey, which is confined to the Virunga volcanoes. The well-known mountain gorilla (Gorilla gorilla beringei) is an endemic subspecies. The gorillas were seriously threatened with extinction due to habitat destruction and hunting. Thanks to energetic conservation efforts, mountain gorilla numbers are currently increasing, and the threats now come from managing the needs of a growing human population around the gorilla habitat, as well as emerging threats from diseases and climate change. A few larger mammals are near-endemic species, such as Grauer's gorilla (Gorilla beringei graueri) and a species of monkey called L'Hoest's guenon.

The Albertine Rift montane forests are centers of geologic activity, with particularly active volcanoes, as well as innumerable endemic species that must face the effects of a growing population recovering from many decades of conflict. These factors combine to make this region one of the most important for conservation and sustainable development. Researchers, zoologists, conservationists, and local organizations have worked together over time to help maintain wildlife populations while recognizing the need for agricultural development due to human population growth along with mining concessions. However, habitat loss is a particularly notable factor for many living organisms, and though it has been partly addressed through the creation of reservations throughout the region and the continent at large, researchers still estimate significant losses over the coming decades. One study extrapolated an average loss of an additional 75 percent of remaining suitable habitat across all species by 2080, on top of what has already been lost and demolished. The same study estimated that by that time, 46 percent of endemic species would be listed as "threatened" on the International Union for Conservation of Nature Red List of Threatened Species.

Despite negative forecasts, population rebounds have been noted as conservation efforts have been taken more seriously within the region. One analysis demonstrated the possibility of conserving all endemic and threatened species in the region, while also allowing for potential future mining developments. However, efforts would need to be taken to redistribute reserve land to ensure wildlife protection.

Bibliography

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Byaruhanga, A., P. Kasoma, and D. Pomeroy. Important Bird Areas in Uganda. Kampala, Uganda: East Africa Natural History Society, 2001.

Chandrasekhar, Aruna. "Endangered African Montane Forests Could Be a Key 'Carbon Store', Scientists Say." Carbon Brief, 14 Sept. 2021, www.carbonbrief.org/endangered-african-montane-forests-could-be-a-key-carbon-store-scientists-say/. Accessed 11 Oct. 2024.

Eilu, Gerald, David L. N. Hafashimana, and John M. Kasenene. “Density and Species Diversity of Trees in Four Tropical Forests of the Albertine Rift, Western Uganda.” Diversity & Distributions 10, no. 4 (2004).

Eilu, Gerald, David L. N. Hafashimana, and John M. Kasenene. “Tree Species Distribution in Forests of the Albertine Rift, Western Uganda.” African Journal of Ecology 42, no. 2 (2004).

Plumptre, A. J., et al. "Conservation Planning for Africa’s Albertine Rift: Conserving a Biodiverse Region in the Face of Multiple Threats." Oryx, vol. 55, no. 2, 2021, pp. 302-310. doi:10.1017/S0030605319000218. Accessed 11 Oct. 2024.

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