Development is destroying large areas of Brazilian grassland© PhotoDisc

Brazil's savannah is vanishing faster than its rainforests, according to a report from the environmental group Conservation International. Without drastic cuts in the amount of land cleared for agriculture, the report's authors say, the grasslands will be entirely wiped out by 2030.

Every year, some 20,000 square kilometres of savannah, an area the size of New Jersey, is destroyed to make room for crops such as soy, wheat and cotton. The savannah region, also called the cerrado, is said to be the world's largest continuous area of land suitable for agriculture.

But the wilderness is also home to a huge range of biological diversity - around 5% of the world's animal and plant species are thought to live there. This biodiversity is being placed in danger by a lack of proper planning, say Ricardo Machado and his colleagues at Conservation International in Brazil.

Part of the problem may be that conservation efforts have traditionally focused on Brazil's endangered tropical rainforests. The savannah, which consists of grasslands dotted with sparse trees and small forests, does not strike the casual observer as a valuable resource. "It's not aesthetically beautiful, so people don't care as much," says a spokesperson for the World Land Trust, a British conservation charity.

Conservation International's researchers discovered the magnitude of the savannah's plight by examining satellite photographs showing land use. They report that around 1.5% of the region's 1.3 million square kilometres of grasslands are cleared each year.

With this clearing comes the development of towns and hydroelectric dams, which threaten to cause problems of their own. The creation of reservoirs can cause local rivers to clog with silt.

Conservationists and other experts are meeting this week in Alto Paraiso, near Brasilia, to discuss the problem. Proposed strategies include restricting development to the areas around existing transport links, and more efficient use of current agricultural land.