There is a considerable overlap between historic cultural centres and centres of biodiversity. Some factors promoting high biodiversity, such as perennial water availability, environmental heterogeneity and fertile soils have also favoured human settlement (Balmford and others 2001). In general, patterns of biodiversity and language diversity coincide (Moore and others 2002), and show parallel extinction risks (Sutherland 2003), suggesting that cultural cohesion and biodiversity sustainability are closely linked.

The most important centres of vertebrate and plant diversity are inhabited by more than 100 million people (Balmford and others 2001) and are areas of intensive land use. These have been identified as “hotspots” (Myers and others 2000). In Africa, these are the Cape Floristic Region, the Coastal Forests of Eastern Africa, the Eastern Afromontane, the Guinean Forests of West Africa, the Horn of Africa, Madagascar and the Indian Ocean Islands, Maputaland-Pondoland-Albany and the Succulent Karoo (CI 2006). Despite their proximity to metropolitan areas and despite often being completely surrounded by transformed land, many sites of primary vegetation remain within hotspots (for example, the Taï and Banco national parks of Côte d’Ivoire, the Table Mountain National Park of South Africa, and parts of the coastal forests of Eastern Africa); these areas contain irreplaceable habitats for endemic species. For example, the Taï National Park currently represents at least 40 per cent of the total remaining forest area of Côte d’Ivoire (Poorter and others 2004).

There are at least two fundamental reasons for Africa’s biodiversity richness:

  • First, it has occupied its position astride the equator for hundreds of millions of years. Its life forms have not, during this period, been wiped clean by glaciers or inundated by oceans, and have been able to gradually accumulate new varieties.
  • Second, perhaps because Africa has been occupied by humans for longer than any other continent, it has not suffered the mass extinctions that followed the arrival of the human species elsewhere.

In this place where humans evolved, people coexisted with other living things, at least until the modern era. That situation is rapidly changing. Major increases in the human population and rising wealth create pressures on land, and on freshwater and marine ecosystems. Global trade has intensified the demand for animal products, tropical timbers, cash crops and seafood. At the same time, global connectedness has brought new problems, such as global climate change, IAS, the spread of viral diseases, and the introduction of new technologies. The result is that biodiversity, so persistent for millions of years, is now under unprecedented threat. These human drivers and pressures are discussed more fully in Chapter 1: The Human Dimension.

Biodiversity underlies the provision of a large variety of benefits that people obtain from ecosystems (MA 2006). These include environmental goods, such as food and wood for energy, and ecosystem functions that depend on particular organisms, for example pollination by bees, or nitrogen fixation by symbiotic bacteria in the roots of legumes. Living organisms are critical in creating the environmental conditions on Earth that make it habitable to humans and many other species by, for instance, regulating the climate and atmospheric composition (Lovelock 1979, Steffen and others 2004, MA 2006).