Itombwe Massif and Forest, DRC

Overview | Data

The Itombwe Massif and surrounding region remains one of the few relativelu undisturbed forests in the Albertine Rift. Located in eastern Democratic Republic of the Congo (DRC) to the west of northern Lake Tanganyika, the Itombwe Mountains include an area of approximately 16,2000 square kilometers that is above 1,500 meters in elevation. Mt. Mohi, located at the northern end of this region, is the highest peak at over 3,400 meters.

The forests of Itombwe are notable for having the highest richness of bird species in Africa, including at least two species that are endemic to the region. This area is also home to 35 mammal species other than primates, as well as thirteen primate species. Of particular interest to primatologists and conservationists working in the Albertine Rift are populations of eastern lowland gorillas (Gorilla beringei graueri) and chimpanzees (Pan troglodytes schweinfurthi). Despite Itombwe's obvious ecological importances, it remains relatively unstudies due to its remote and mountainous location. While conservation efforts in the past have been thwarted by ongoing violence in the region, recent undertakings have drawn together local community leaders with national and international agencies in order to formulate management strategies aimed at integrating conservation and sustainable resource use in the region.

 

Natural Environment

The Itombwe region is located in eastern DRC, within the hilly landscape characteristic of the western edge of the Albertine Rift system. Of this area, almost half is covered by Albertine Rift montane forest; an additional 12% of the landscape is covered by either bamboo or montane gallery forests. While the name "Itombwe" is often used in reference to this entire section of landscape, it also refers more specifically to the Itombwe Massif, a large fault-blocked and uplifted plateau. The Massif, which is a distinct geological formation within the greater Itombwe forested region, comprises approximately 75% of its total area. Slightly more than half the land surface of the Massif lies between 1,500 and 3,500 meters in elevation; this area is almost entirely covered by montane or bamboo forests, moorland heath, or a unique complex of alpine savanna and forest. This almost unbroken block of forest contains what is possibly the only remaining ecologically intact transition zone between montane forest and alpine savanna in Africa.

The Itombwe Massif's remote location and mountainous terrain has kept it one of the least accessible and therefore least studied areas in the Albertine Rift region. However, the same characteristics that have prevented thorough exploration of these forests have also protected them from encroachment; Itombwe is home to some of the most intact and expansive remaining forests in the Albertine Rift region. Although very little is known about specific floral species and communities within this mosaic of landscapes, Itombwe's unique position spanning a range of elevations indicates the potential for high species richness and overall diversity.

There is slightly more known of the incredibly faunal diveristy of Itombwe's environs. This area is best known for its incredible richness of bird species, including at least three species endemic to Itombwe's forests, and for its populations of forest gorillas and chimpanzees. In addition to the thirteen primate species that have been documented in this region, there are at least seventy non-primate mammal species, of which fifty-four are large mammals including elephants, leopards, bongo, and duikers.

As of the last comprehensive primate survey in the late 1990s, the Itombwe Massif was home to approximately 1,150 Grauer’s gorilla (Gorilla beringei graueri).  These gorillas are found only in localized, discrete geographic locations ranging in size from under 100 km2 to several hundred square kilometers.  Within these areas, population densities range from 0.3 to 3.7 individuals per km2.  Gorillas are not found in forested areas between these established habituated zones, the locations of which may be linked to habitat requirements.  Chimpanzees (Pan troglodytes schweinfurthii) in Itombwe are both more abundant and more widely dispersed than gorillas.  Additional primate species found in this area include the olive baboon, red-tailed monkey, and at least two species of colobus. 

Itombwe has been described as the single richest area in Africa for birds.  At last count, this area was home to 563 species of bird, including three endemics: the Congo bay (Itombwe) owl (Phodilus prigoginei), Schouteden’s swift (Sachoutedenapus schoutedeni), and Prigogine’s nightjar (Caprimulgus prigoginei). 

 

Land Use

The Itombwe Massif is located outside the main population belt of the Albertine Rift, and abuts the vast Congo Basin forests to the west.  Its geographic location, coupled with rugged topography and high elevation, has historically stymied settlement in this area.  The result is a landscape relatively undisturbed and unfragmented by agriculture or other human land use practices.  The interior of the Itombwe Massif remains largely uninhabited, while a few scattered villages exist along roads and near forest edges along the Massif’s perimeter.  Human population densities in this area depressed due to poor soil arability, although subsistence agriculture is still widely practiced where settlements have managed to survive.  Cattle are grazed in relatively open forests and in savannas and meadows that exist in a patchwork with denser forest.  The northern portion of the Itombwe region supports a greater human population, and therefore has been subjected to more intensive natural resource use, while the southern portion is relatively uninhabited.

Corn stalks grow among the tree stumps in a recently cleared plot at the forest's edge

Forests are exploited for timber, which is used both locally and sold in nearby markets.  Commercial logging has been limited to the selective removal of relatively few individual trees due to the difficulty in accessing the region’s forests.  Mining for gold and casserite (tin) are economically profitable activities in Itombwe. 

 

Conservation Threats

The most severe threats to the ecological integrity of Itombwe’s forest and its unparalleled faunal diversity stem from the burgeoning local population.  The most pervasive threat is the deforestation and degradation of forested areas that accompanies smallholder, subsistence farming.  The soils of the Itombwe region are not well suited to support agriculture—as the land quickly loses its fertility people are forced to relocate to new areas of the forest, where they clear all existing vegetation to make way for crops.  Thus the process of deforestation and degradation is perpetuated across the landscape.  As populations continue to grow, augmented by thousands of refugees fleeing continuing violence in Rwanda, Burundi, and eastern DRC, the rates of forest loss and fragmentation grow apace.  Additionally, the integrity of forested areas along the edges of settlement is threatened by selective timber harvests and the removal of trees for fuelwood.

Within the remaining intact forest blocks, large mammal populations are threatened by poaching and bushmeat hunting.  Unprotected populations of buffalo, elephants, gorillas, chimpanzees, duikers, and other animals have been decimated, some even to the point of extirpation, by unrestrained hunting.  Itombwe’s forests are some of the last remaining large tracts of wilderness in the Albertine Rift Valley and currently support some of the most robust populations of large mammals on the continent.  The specter of continued habitat loss coupled with hunting pressure represents a growing threat to the continued ecological integrity of this region. 

Despite its obvious ecological importance as one of the last refuges for endemic Albertine Rift flora and fauna, the Itombwe Massif remained completely without protection until very recently.  Efforts to designate the area as a nature reserve in the late 1990s were thwarted by pervasive violence in the region.  Recently, local chiefs in the areas surrounding Itombwe spearheaded an effort to develop a management scheme for this region, including designation of conservation and sustainable development areas within the forests.  Local leaders engaged the cooperation of national and international government bodies and NGOs in a campaign which culminated in October 2006 with the designation of a portion of Itombwe’s forests as a nature reserve.  The newly created Réserve Naturelle d’Itombwe will focus on integrating local development needs with conservation of the area’s vast cache of forest resources.