biodiversity > features > hotspots in focus
Hotspots in focusPosted: 02 Mar 2001
Here we review some major biodiversity hotspots around the world and the threat to the many key species and plants in these regions.
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Madagascar | Western Ghats and Sri Lanka | Mediterranean Basin
Guinean forests |
� Oliver Langrano/Still Pictures
Located 240 miles (400 kms) off the east coast of Africa, the world's fourth largest oceanic island, Madagascar, has been separated from other land masses for more than 160 million years. Its unique plant and animal species have evolved in isolation, resulting in high rates of endemism which distinguish Madagascar as a biodiversity hotspot. More than 7,000 species of higher plants, 78 mammal species and 450 reptile and amphibian species are found exclusively in Madagascar.
The greatest threat to the biodiversity of Madagascar is deforestation. Approximately 90 per cent of Madagascar's primary forest habitat has been lost due to cattle grazing, agriculture, firewood, logging, and mining. As communities encroach upon remaining natural habitats, even the forests and wildlife that occur within protected areas are threatened.
Western Ghats and Sri Lanka
� Roland Seitre/Still Pictures
The mountains of the Western Ghats of southwestern India and the highlands of southwestern Sri Lanka are separated by 400 kms of water, but they are strikingly similar in their geology, climate, and evolutionary history. A high number of species, many endemic, are found in both parts of this hotspot. Approximately 18 million people rely on resources from the forests in the Western Ghats and Sri Lanka. These forests include more than 4,700 species of plants, 46 per cent of which are found only in this region. High demand for forests species with commercial value, along with rapid development has put this hotspot under critical threat of biodiversity loss. Species like the Indian tiger and the Asian elephant, whose numbers have dwindled due to poaching and loss of habitat, have become important international "flagships" for tropical forest conservation.
� Michel Gunther/Still Pictures
One of the largest and most populated of the hotspots, the Mediterranean Basin encompasses 2.3 million square kilometres. It is home to more than 300 million people and stretches from Portugal to Jordan and from the Canary Islands to northern Italy. Eight per cent of the Earth's plant species can be found in this hotspot - a richness of species exceeded by only the Tropical Andes. More than half of the 25,000 plant species are endemic to the Basin and new species are discovered regularly. While the numbers of species of plants in the Basin are impressive, they are found in small numbers among scattered patches broken up by agriculture and urban development. Of the vertebrates, reptiles and amphibians occur in the greatest numbers followed by birds and mammals.
� Schafer & Hill/Still Pictures
Incorporating parts of Sierra Leone, Guinea, Cote d'Ivoire, Cameroon, Nigeria, and Ghana, and all of Liberia, the Guinean Forests of West Africa have an abundance of flagship species and a high rate of endemism. The pygmy hippopotamus, Diana monkey, and drill (a large forest-dwelling baboon) are all endemic to this region. As many as 9,000 species of plants exist in these forests, of which some 2,250 are endemic.
Threats to the wildlife in the Guinean Forests include extensive habitat fragmentation and deforestation due to logging, slash-and-burn agriculture, and mining. Bushmeat hunting for local consumption and trading has also led to declines of primate and antelope populations, and ivory poaching threatens forest elephants.
� R. Kennedy/Still Pictures
The Philippines is dubbed the "hottest of the hotspots" because only 6-8 per cent of the country's original vegetation still exists. Extreme pressure is being put on the biodiversity of the Philippines due in large part to population growth and development. The more than 7,000 islands of this archipelago are home to exceptionally high numbers of plants, birds, and mammals. More than 30 per cent of the birds - including the Philippine eagle, the largest and rarest eagle in the world - are found only in the Philippines. 76 per cent of the higher plants and 55 per cent of the mammals are also endemic to this country.
The incredible biodiversity of the Philippines also extends to its seas, which probably have the highest diversity of coral species on Earth. The Philippine seas are also threatened, however, by cyanide and dynamite fishing and coastal development.