There are 53 countries and one 'non-self governing territory' (Western Sahara) in Africa. Ecologically, Africa is home to eight major biomes - large and distinct biotic communities with characteristic assemblages of flora and fauna. Chapter One of the Atlas vividly illustrates Africa's geographical attributes, presenting a physical setting in which readers may visualize the changes human actions are etching on the landscape. Maps, images and informative text reveal that Africa is endowed with rich natural resources that provide the basis for its peoples' livelihoods. Among the varied environmental features readers can see are rain forests, wetlands, mangroves, coral reefs, and coastal deltas. These ecosystems provide a rich and diverse array of potential sources of food and materials. In addition, Africa holds approximately 30 per cent of the earth's minerals including 40 per cent of the gold, 60 per cent of the cobalt and 90 per cent of its platinum. In recent years, oil production has been the main contributor towards Africa's economic growth. There are also grazing and agricultural lands that can support farming economies, as evidenced by the 56.6 per cent of Africa's labour force engaged in agriculture.