Chapter VII. Trends in Land and Natural Resource Use

Rural populations, particularly those living in forest zones, rely almost entirely on the natural resource base for their subsistence. The forest is essential as a source of shelter, food, and energy. Most rural people extract a wide range of non-timber forest products (NTFPs), such as bushmeat, vegetables, fruits, saps, medicines, and mushrooms. For many people living in sparsely settled rural areas with limited or no access to agricultural markets, the revenues they generate from their use of forest resources continue to meet most of their needs.

Forest resources have been able to meet the needs of the indigenous population for hundreds of centuries, but the human population in Africa has increased eightfold since 1900 and is expected to double in the next 25 years. Even if consumption patterns of forest resources do not increase, harvesting pressure on most wild resources is likely to rise in the near future beyond sustainable levels. Harvesting of many NTFPs and of bushmeat is already unsustainable in many areas in Central Africa (Sunderland et al. 1999; Wilkie and Carpenter 1999a).

The human impact on forest and savanna landscapes takes the form of conversion to agriculture, settlements, or infrastructure, or of resource extraction. Agriculture, logging, fishing, hunting, NTFP harvesting, and water resource use all occur across national and land-ownership borders. In the Central African region, the most acutely felt impact is probably that of cross-border illegal hunting and transportation of wildlife.

A. Agriculture

More than 24 million people inhabiting the forests of Central Africa (Bahuchet and de Maret 1995) rely on shifting cultivation to meet their dietary needs. Assuming an average field size of 0.2 hectares per adult equivalent (Wilkie et al. 1999) and a conservative fallow period of 20 years (Bahuchet and de Maret 1995), Central Africa’s farmers need approximately 20 million hectares of land for sustainable cultivation. This is equivalent to 11 percent of the forest lands within all Central African nations, and matches the area of forest that is already degraded today, as estimated using remote sensing image analysis (Laporte et al. 1998) (Table 10).

Even were agricultural practices to remain largely unchanged, almost all forest in the Central African Republic might be converted to agricultural land by 2025. Even in Gabon, where 60 percent of the population of 1 million lives in cities, more than 20,000 square kilometers of forest might be degraded over the next 25 years (assuming that most food in Gabon is produced domestically). Both Cameroon and Equatorial Guinea risk seeing the percentage of degraded forest increase to more than 50 percent by 2025.

Source: Mayaux et al. (1997).

B. Logging

Logging is important as a source of employment and national revenue, and is a primary cause of degradation of the forest estates. In 1998, timber generated 28 percent of all nonpetroleum export revenues and millions of dollars in taxes in Cameroon. The logging sector is one of the largest employers in both Cameroon and Gabon, and often plays a key role in bringing roads, education, medical care, and electricity to rural areas (Bikie et al. 2000; Collomb et al. 2000). Logging companies are both the de jure and de facto managers of huge areas of forest in Central Africa. In Cameroon, 80 percent of the forest estate outside of protected areas is zoned for logging (Bikie et al. 2000); in Gabon, the figure is 50 percent (Collomb et al. 2000).

Unlike in the Diptocarp forests of tropical Southeast Asia or in temperate forests where timber companies fell most, if not all, trees in a given area, logging in Central Africa focuses on three to five primary species that may be sparsely distributed throughout the forest. Although as many as 80 species of trees are logged commercially, fewer than five account for the majority of wood exports. In Cameroon, Sapelli (Entandrophragma cylindricum) and Ayous (Triplochiton scleroxylon) comprise more than one-third of all logs exports; in Gabon, Okoumé (Aucoumea klaineana) accounts for more than 70 percent (Bikie et al. 2000; Collomb et al. 2000).

In northern Republic of Congo in 1989, the SFAC (Societé Forestiere Algero-Congolaise) concession removed, on average, one tree every 6.6 hectares. Sapelli (E. cylindricum) accounted for more than 75 percent of all trees felled. Comparison of inventory and logging records showed that more than 90 percent of all Sapelli trees within the SFAC concession that exceeded minimum statutory size limits were removed (Wilkie et al. 2000b).

Selective logging of tree species that occur at low densities within the forests of northern Republic of Congo typically removes or damages less than 7 percent of the canopy. The extent of disturbance at felling sites is in fact likely to be less than that of natural tree falls (Hart et al. 1989), as any attached lianas are cleared prior to tree cutting, thus reducing pulldowns of neighboring trees or tree limbs.

The reduction in canopy cover by logging in Central Africa (Struhsaker 1996 and 1997; White 1994; Wilkie et al. 1992) is considerably less than the 30 percent threshold estimated by Skorupa (1986) that would adversely affect primate species in a Ugandan forest, and is less than the 38 percent estimated by Thiollay (1992) to have caused a 25–30 percent loss of bird species richness in a Guyanan forest. Canopy removal as a result of one cycle of selective logging, typical of old-growth logging in Central Africa, may not therefore have a major adverse effect on forest primates and birds. This contention is further bolstered by the fact that commercially exploited tree species are primarily wind-dispersed emergents, and thus are not major food sources for frugivorous primates and birds. In fact, vegetation regrowth that occurs after a logged area is abandoned may increase the availability of food for folivorous species such as elephant (Fay 1991), gorilla, and duikers (Carroll 1996; McCoy 1995; Nummelin 1990). The near-complete removal of old-canopy-height Sapelli trees may, however, adversely affect species-dependent folivores and their predators, and may reduce the availability of some species of caterpillars that are seasonally collected by humans as a food source (Hladik et al. 1990).

The old-growth logging that is the characteristic practice throughout most of Central Africa progresses like a wave over the landscape as timber companies enter into unlogged areas in search of the few valuable trees that are scattered throughout the forest. Once these are logged the company quickly moves on to the next area. To find and harvest these trees, loggers must construct numerous survey trails and roads; this both heavily fragments the forest and opens it up to hunters. A hunting trip that might have taken days to undertake before the arrival of logging may be reduced to a few hours when the hunter can hitch a ride on a logging vehicle (Auzel and Wilkie 1999). With a ride from the logging company, the bushmeat hunter additionally no longer has to carry his catch on his back, and can kill many more animals on each trip. Logging companies thus not only directly increase demand for meat by bringing in a large workforce, they also greatly facilitate the entry of workers into the commercial supply of bushmeat to urban markets (Wilkie et al. 2000b).

C. Fisheries

Although most ethnic groups in Central Africa consume fish, only 11 are specialist riverine fishers, and 5 specialist marine fishers (Bahuchet and de Maret 1995). Fishers primarily use nets, traps, or long-lines, but poison fishing and dynamiting also occur throughout the region.

Coastal fish stocks from Guinea to the Democratic Republic of Congo are typically less abundant than those from Mauritania north, and Angola south. The large trigger fish stock (Balistes spp.) has now virtually disappeared in this region. Fishing of demersal stocks has been concentrated on inshore zones and on juveniles, and most demersal stocks are now fully exploited or overexploited, economically and biologically. The state of deep shelf and slope resources is not well known, however. Small pelagic species (Sardinella aurita, S. maderensis, Scomber japonicus, and Engraulis encrasicolus) are important, and constitute a shared but highly variable resource. Those in the western Gulf of Guinea are considered fully exploited, but the biomass of those in the southern Gulf of Guinea may actually be increasing (FAO 2000).

The management of tropical stocks seems to favor species assemblages and communities rather than individual species, aggravating the difficulties of stock assessment and therefore the adoption and implementation of appropriate management measures (FAO 2000).

Lack of information on the abundance, recruitment, and movement patterns of most riverine and lacustrine fish species makes estimates of the sustainability of riverine and lacustrine fishing and the value of transboundary fishery management mere speculation (Robin Abell, pers. comm.). Massive illegal overhunting of hippopotamus in the Rwindi region of the Virunga National Park in the Democratic Republic of Congo to supply meat to refugees in Goma and Bukavu is likely to have substantially reduced the nutrient flows into Lake Edward (Lac Idi Amin Dada), and consequently the production of the algae and algal-eating cichlids that form the basis of a substantial regional fishery.

D. Water resource uses and environmental impacts

The high volume of river flow and the fact that the underlying geology of the area has led to the formation of steep falls or rapids near the coast means that the rivers of Central Africa have tremendous hydropower generating potential (Revenga et al. 1998). Dams on some shared rivers for the production of hydroelectric power or irrigation water have been constructed or are under consideration, including the following:

• Inga Shaba dam on the Congo River. The Inga Shaba dam supplies electricity to the Democratic Republic of Congo, the Republic of Congo, and Angola. At full capacity (i.e., continuous operation 24 hours per day, 365 days per year) the 1,800 megawatt powerstation could generate 15 billion kilowatt hours per year, or twice the total energy consumption of all Central African states.
• The Rusizi I and Rusizi II dams on the Rusizi River between Rwanda and the Democratic Republic of Congo. These two dams produce electricity for the Democratic Republic of Congo, Rwanda, and Burundi.
• Lake Lagdo in Cameroon was created in 1986 with the construction of a dam on the Benue River. The dam reduced peak riverine discharges (measured at Yola, Nigeria) by 44 percent, from 3,330 to 1,870 cubic meters per second.
• Studies are underway for the construction of a dam at Rusumo on the Kagera River, with the intention of supplying electricity to Rwanda, Burundi, Tanzania, and Uganda.
• Waza-Logone irrigation dam in the far north of Cameroon, close to Lake Chad.

Hydropower delivers 80 percent or more of all electricity consumed in Cameroon, the Democratic Republic of Congo, Ghana, Mozambique, Rwanda, Uganda, and Zambia. With the Democratic Republic of Congo, Cameroon has the greatest potential in Africa for hydroelectric power generation. More than 110 possible sites have been identified, with a combined potential capacity of 500,000 megawatts. If Cameroon develops its electricity generating potential, it could become a net electricity exporter (See http://www.eia.doe.gov/emeu/cabs/cameroon.html).

Hydropower generation in the region is a mix of run-of-river and reservoir-cascade systems. At present the impact of dams across the region on river flow, upstream sedimentation, and fish movements is relatively low (Shumway 1999). Widespread use of the Schneider HydroEngine low-dam hydropower system could enable the low-cost, low-environmental-impact electrification of population centers near major rivers.

Water pollution

Levels of pesticide and fertilizer use for agriculture are extremely low throughout the region. Runoff and downstream pollution are typically not problems, with the possible exception of areas surrounding the few remaining industrial-scale rubber, coffee, banana, and oil palm plantations.

Oil prospecting, drilling, and refining occur along the Atlantic coast where oilfields are being exploited. Countries engaged in this business include Cameroon, Equatorial Guinea, the Republic of Congo, Angola (Cabinda), and the Democratic Republic of Congo. Oil prospecting and drilling produce large quantities of mud, which can pollute coastal waters. Water pollution by oil waste has been observed in Limbe and Edea in Cameroon (Mbog 1999) and in Conkouati in the Republic of Congo (Makaya 1999).

The absence of or incomplete sewage treatment means that urban waste is dumped into rivers and coastal waters, contributing to riverine, lacustrine, and marine water pollution and to a decline in aquatic diversity (Makaya 1999; Mbog 1999). In some coastal areas, mangroves are heavily exploited for wood to smoke fish and for firewood. According to Nkéoua and Nkombo (1999), overexploitation of mangroves for fish smoking has in some areas caused the degradation of the natural habitat of aquatic species.

Some activities linked with marine, river, and lake transportation also constitute a source of water pollution. The United Nations Environment Programme (UNEP) estimates that leaching of the copper antifouling coating on ship hulls can cause pollution of ocean waters and sediments, causing detectable inhibition of photosynthesis in marine microalgae and bioaccumulation in zooplankton (Mbog 1999). Small boats also introduce invasive species that can threaten local ecosystems and species. The Water Hyacinth (Eichoniea crassipe), for example, is spreading throughout the region, reducing navigation capacity and fish production, accelerating evapotranspiration, and degrading the biodiversity of lakes and rivers

E. Non-timber forest products

Non-timber forest products (NTFPs) are frequently touted as important to household consumption, thus enhancing the value of standing forest and discouraging deforestation. While recent research confirms that NTFPs provide sources of food, medicine, and income to many households in Central Africa (Sunderland et al. 1999), however, these studies also confirm that the contribution of NTFPs to local and national economies is typically small relative to agriculture. In four forest villages in southwestern Cameroon, NTFPs contributed 9 percent to the household economy, compared with the 43 percent contributed by agriculture (Vabi and Tchamou 1999). Joiris (1996) reports similar figures for households in southeastern Cameroon (NTFPs 1.2 percent; agriculture 31 percent) and southwestern Central African Republic (NTFPs 10 percent; agriculture 51 percent). Harvesting of wild NTFPs is most important for poor families that have limited or no access to agricultural markets. Wealthy households or those with access to agricultural markets (i.e., those that can sell cash crops) often consume NTFPs, but seldom harvest them for sale (Ambrose-Oji 1997).

In the southwest and northwest provinces of Cameroon, the total value of NTFP production and marketing exceeded US$ 19 million in 1999, and contributed 2.8 percent to the regional economy. Timber, in this predominantly logged-over area, contributed 5 percent, and agricultural crops 27 percent (Abwe et al. 1999). In areas of Cameroon where old-growth trees have yet to be harvested the value of logging is considerably higher.

Harvesting of wild NTFPs is dirty, arduous, and at times dangerous work. Wild harvesting and processing of NTFPs is usually labor-intensive and is typically economically feasible only when the opportunity costs of labor are low or when prices for NTFPs are high. As a result, harvesting of wild NTFPs is typically a symptom of poverty rather than a cure for it.

The relatively small contribution of NTFPs to household economies in Central Africa is mirrored by results of a recent review of global forest valuation studies (Costanza et al. 1997). Average worldwide values (converted to 1994 US dollars, with an additional correction for purchasing power) of tropical forests for food production, raw materials, and intangibles such as carbon sequestration, biodiversity conservation, and ecological services were US$ 32, US$ 315, and US$ 1,660 per hectare per year, respectively. Estimates of the direct (i.e., tangible) value of the forest may, however, be exaggerated, given the short duration of most studies. When Godoy and his colleagues (2000) directly measured and valued forest resource consumption patterns of 32 indigenous families in Honduras continuously over two and a half years, the direct value of the forest to local communities was in the range US$ 18–24 per hectare per year—considerably lower than the global average of US$ 347.

These studies suggest that tropical rain forests are worth more for their global than for their local values (Chomitz and Kumari 1998), and that NTFPs may be less likely than previously thought to provide economic incentives to conserve tropical forests.

NTFPs do provide critical supplies of food during periods when agricultural crops fail or are otherwise scarce, but one must be cautious before attaching too much weight to the insurance value of the forest. Rural people can protect themselves against mishaps either by taking precautionary measures before shocks take place, for example, by intercropping or plot scattering, or by relying on reciprocity, tolerated theft, or out-migration after shocks strike (Godoy and Wong 2000).

Many have argued for the increased commercialization of NTFP use as a means of increasing the relative contribution of NTFPs to household economies, raising the value of intact forest, and discouraging forest clearing. The following paragraphs review the evidence for the sustainability of commercial NTFP production in Central Africa.

While NTFPs have been used for millennia, the human population of the forested regions of Central Africa is higher now than it ever has been in history, and is likely to double to more than 60 million within 20 years. As with any wild plant or animal, if harvesting exceeds annual production, resources will progressively be depleted and will become locally extinct.

NTFPs prized for their leaves, roots, or bark are particularly prone to unsustainable use, because harvesting either damages or kills the parent plant. Commercial demand for Gnetum and harvesting practices that destroy the parent plant have driven wild populations of this leafy vine to local extinction in Nigeria and much of southwestern Cameroon. Cameroon can supply approximately 200 tons of Prunus africana bark sustainably each year, but in 1999 more than 3,500 tons were harvested and exported. Worse, for both Prunus africana and Pausinystalia johimbe, “sustainable” harvesting practices that partially strip bark from live trees exposes them to stem-boring insects that can result in 50–90 percent post-harvest tree mortality (Cunningham et al. 2000).

There is growing evidence that as NTFPs increase in value there is a trend toward the overharvesting of wild resources, increased on-farm production, and exclusion of resource users by resource managers. Of the 20 most economically valuable NTFPs in Central Africa, 11 are unsustainably harvested and 12 are now cultivated (Wilkie 1999). This trend suggests that few if any commercially valuable NTFPs can be harvested sustainably from the wild, given the existing resource access and ownership laws.

Two major options are available for the management of NTFPs. The first, domestication and on-farm cultivation, is appropriate when wild resources are being overexploited and are at risk of local extinction. Several NTFPs, including Irvingia, Dacryodes, Ricinodendron, and Piper, are already grown within farmers’ fields, and field trials are demonstrating the potential also for on-farm cultivation of Gnetum and rattans. The second option involves putting in place systems to define who should have access to wild NTFP resources in a given area, and to regulate harvest levels. This would require the privatization of forest resources at the household or community level—a complex political process that has barely begun in Central Africa.

Without reform of access to NTFPs, most commercially valuable NTFPs will be overharvested in the wild. On-farm cultivation will increase the economic value of NTFPs to landowner families, but will decrease NTFP access for landless families. And while on-farm cultivation of high-value NTFPs may reduce pressure to harvest from the wild, it may increase the incentive to clear forest to cultivate these new crops.

In summary, recent evidence strongly suggests that NTFPs contribute little to household economies relative to agriculture, and are thus unlikely to provide an economic incentive for conserving intact forests.

F. Transborder use of natural resources

The high porosity of international borders and the absence within nations of impediments to resource use across land-tenure borders means that timber exploitation, oil prospecting and drilling, mineral extraction, agricultural settlement, livestock grazing, fishing, and wildlife hunting often occur across political and land-use boundaries.

The single most critical factor threatening the conservation of forest resources across borders is the hunting of wildlife for meat, medicines, and the live animal trade (Bowen-Jones and Pendry 1999; ECOFAC 1998; Robinson and Bennett 1999b; Wilkie and Carpenter 1999a).

1. Bushmeat

The major threat to the sustainable management and conservation of wildlife in the Central Africa region is the commercial hunting of wild animals for meat. Bushmeat is highly appreciated by many people in the area, primarily because it is often less expensive and more readily available than domestic alternatives such as beef or chicken. For instance, a 10-month study by Kornelia Ioveva-Baillon indicated the annual flow of bushmeat into Yaoundé, Cameroon, by train to be about 816,710 kilograms. Steel (1994) estimated the annual quantity of bushmeat received by the Mont Bouë, Oloumi, and Nkembo markets in Libreville, Gabon, to be about 500,000 kilograms. The quantity of meat sold annually in Bukavu in the Democratic Republic of Congo is estimated to be about 400,000 kilograms. In total, it is probable that more than 1 million metric tons of bushmeat is harvested each year from the forests of Central Africa (Wilkie and Carpenter 1999a).

Cross-border hunting is common in Central Africa. It is indiscriminate and involves species recorded in the IUCN Red List of threatened species. The transboundary forest between Cameroon, the Central African Republic, and the Republic of Congo is open to the local communities, who use them mainly for hunting, fishing, gathering, and cultural ceremonies, regardless of administrative boundaries. Zouya-Mimbang (unpublished report, 1998) found a group of hunters from the Central African Republic settled in Molongodi, southeast Cameroon, where they practice hunting and fishing throughout the year. Camps of Central Africans are also established along the Koumela–Libongo road in southeast Cameroon.

Usongo and Curran (1986) reported a trade of bushmeat from the Lobéké region of Cameroon across the Sangha River to the Central African Republic, and also overland to internal Cameroon and other centers. Cameroonian hunters sell their bushmeat at Ouesso town (Republic of Congo) (Zouya-Mimbang 1998); Congolese cross the border with bushmeat to sell in Kika in Cameroon, in exchange buying manufactured products to take back home. In most cases, the bushmeat trade is facilitated by logging activities, with middlemen hitching rides on logging company trucks to transport their bushmeat.

According to Sournia (1998), Manovo–Gounda–Saint Floris National Park in the Central African Republic was for a long period the target of poachers sponsored by the APLS (Armée Populaire de Libération du Soudan, a Sudanese rebellion movement). Well-organized groups of poachers crossed the border seeking ivory, trophies, and bushmeat that subsequently were sold to help finance the war. Cross-border bushmeat hunting by Sudanese and Chadian poachers is also common in most Central African Republic-protected areas bordering Sudan and Chad (Damio and Sélébangue 2000).

Inadequate policing permits Congolese poachers to cross the Ngoko River that separates Cameroon and the Republic of Congo for game hunting in southeast Cameroon. According to reports by local communities, wildlife in the area between Socambo and Mongokélé has become scarce due to excessive hunting (Zouya-Mimbang 1998).

Local authorities in Gabon are similarly concerned that cross-border poaching is depleting wildlife stocks in the Minkébé reserve. While acknowledging the historic links between the population of southern Cameroon and the Minkébé, they believe a solution must be found to the problem of excessive poaching. Lacking the resources to address the problem alone, they are seeking the cooperation of Cameroon and the Republic of Congo. (Ndongo Allogho, pers. comm.)

2. Trade in ivory, skins, and other animal parts

In addition to bushmeat, wildlife is also hunted for secondary products such as ivory, rhino horn, and skins for trade on the international market. Between 1990 and 1998, 1,700 kilograms of ivory was seized at the Douala International Airport in Cameroon (Bello 1998). In 1997 alone, more than 200 elephants were killed for their tusks in the Sangha region of the Republic of Congo.

The trade in ivory culled from the Minkébé Forest is highly visible in the villages of southern Cameroon, particularly in Lélé and Alati in the Cameroon–Republic of Congo–Gabon region (De Watcher, Huijbregts, Ndongo Allogho, dir. comm.). A single hunter may have as many as 400 traps in the Minkébé Forest, and at least one elephant is killed every three days. The ivory hunters are believed to come mainly from gold mining camps near Minkébé and Menvé, and the Haut-Ivindo, Gabon, where a well-organized network of Baka and West Africans trades via Alati and Lélé in Cameroon, Makokou and Mvady in Gabon, and Garabizame in the Republic of Congo. (Ndongo Allogho, dir. comm., 2000).

Cross-border poaching by Nigerian hunters has been reported in Cameroon’s Korup National Park (Culverwell 1998; Vabi and Tchamou 1999), and by Nigerian and Chadian poachers in the Waza and Faro protected areas, also in Cameroon (Ngantou, pers. comm. 2000). Campo Ma’an National Park in Cameroon is also subject to cross-border poaching by hunters crossing the Ntem River from Equatorial Guinea (Ngouadjio, pers. comm., 2000). Cameroonian poachers, in their turn, are reported to hunt elephant in Rio de Campo in Equatorial Guinea (Nicanor, pers. comm., 2000).

3. Live animal trade

Some animal species are trapped and sold alive in domestic and foreign markets for ornamental or research purposes. This trade involves, among others, primates (Cercopithecus, gorillas, and chimpanzees), birds, including parrots (WCS 1996), and reptile and fish species. The extent of the cross-border trade in live animals within the region is not documented.

4. NTFPs

The international trade in Gnetum (leaves), Prunus africana, Garcinia lucida, and Pausinystalia johimbe (bark), and Laccosperma secundiflorum and Eremospatha macrocarpa (rattans) is resulting in overharvesting in Central Africa, and in many areas closest to the centers of demand, such as the border of southwest Cameroon and Nigeria, the local extinction of these plant species (Cunningham et al. 2000; Shiembo 1999; Sunderland et al. 1999).