Chapter 2: State and Trends
situation, in combination with increased populations and trade in fuelwood and charcoal, depletes significant areas of forests across the continent. The depletion is extensive in peri- urban areas. For example, fuelwood and charcoal collection and production are estimated to have caused about 24.6 per cent (29 268 hectares) and 19.58 per cent (23 308 hectares) of the degradation and deforestation of closed woodland, respectively, in areas around Dar es Salaam, Tanzania, and to have depleted 92 761 hectares (50.8 per cent) of open woodland in the same area (Malimbwi and Zahabu 2008). According to Megevand et al. (2013), Kinshasa, a megacity of 8–10 million inhabitants, consumes about 5 million cubic metres of fuelwood annually, which is harvested from degraded forest galleries within a radius of 200 kilometres of the town. Similar findings have been reported for most of the other cities in Central Africa, including Kisangani, Brazzaville, Pointe Noire, Libreville, Franceville, Port Gentil, Douala, Yaoundé and Bata. It is also worth noting that charcoal production in the Congo Basin increased by about 20 per cent between 1990 and 2009 (Megevand et al. 2013).
Beyond the threats related to habitat fragmentation and destruction, poaching too has become a significant menace to African biodiversity, causing alarming declines in species, particularly large-bodied ones, including mammals, birds and amphibians. Large mammalian species are particularly targeted for their meat and commercial value. Recent research indicates that charismatic species such as elephants will become extinct if current rates of poaching continue (Maisels et al. 2013), with the northern white rhinoceros (Ceratotherium simum), a species endemic to Democratic Republic of the Congo, nearly extinct in the wild because of poaching. Large forest tracts, such as the Salonga National Park in Democratic Republic of the Congo, have become vastly less densely occupied by large mammals. To many conservation biologists practising in Africa, poaching is a major driver of diminishing species populations across the continent. Another potential threat is disease outbreaks, especially among primates (Inogwabini and Leader-Williams 2012) such as chimpanzees and gorillas, which can contract serious human diseases. The 2003/2004 Ebola outbreak
in the range of the western lowland gorilla wiped out large numbers of individuals and could, if prolonged, have exterminated the whole species (Walsh et al. 2007; Walsh et al. 2003).
In addition to forests, Africa has extensive rangelands, which include natural grasslands and savannahs, covering 65 per cent of the region’s total land area and providing habitat for domestic livestock, wild plants and wild animals (Niamir- Fuller et al. 2012). Rangelands are rich in floral diversity as demonstrated by the average areal richness of savannah, which is about 1 750 species per 10 000 square kilometres, compared to 2 020 species per 10 000 square kilometres in rainforest (Menaut 1983). Blench and Sommer (1999) reported that the rangelands of East and Southern Africa shelter the greatest diversity of large mammals in the world.
Arid and semi-arid rangeland ecosystems are characterized by seasonal climatic extremes and unpredictable rainfall patterns, but they contain a great variety of biodiversity, much of which is highly adapted to dryland ecology. Species in these drylands have developed unique strategies to cope with low and erratic rainfall. They are drought tolerant and also highly resilient, recovering quickly from disturbances such as fire, herbivore pressure and drought.
Africa’s rangelands are under threat of biodiversity loss due to the degradation of ecosystems and habitats caused by encroachment by woody plants, high livestock and human populations, weakening of traditional resource management strategies, uncontrolled fire, expansion of villages and towns, expansion of crop cultivation, recurrent droughts and invasive alien plant species (Kebede 2009; Gemedo Dalle et al. 2006; Oba and Kotile 2001; Oba et al. 2000; Scholes and Archer 1997). Conversion of rangeland to cropland and other land-use types also causes rangeland degradation and biodiversity loss (Gemedo Dalle et al. 2006).
The many and diverse aquatic ecosystems such as wetlands, rivers, lakes and coastal environments provide habitat for a rich and unique aquatic biodiversity. Equally important are marine ecosystems. According to PERSGA GEF (2003),
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