Brazil has become the world's largest soy exporter

The Pantanal - the world's largest wetland - stretches across areas of Brazil, Paraguay and Bolivia.

The report warned that the greatest threat comes from the intensive use of pesticides and fertilisers in Brazil's Mato Grosso state.

The region could deteriorate like the Everglades in Florida, the report said.

From the moment you have data showing there is a problem, it's better to prevent it before it becomes too late," Dr Paulo Teixeira, the UN scientist who led the study, told the Associated Press news agency.

Soy farming

"In the United States, the government is spending $8bn [�4.2bn] to undo the environmental problems in the Everglades and that's a massive sum, too much for a country like Brazil," he added.

The Everglades was hugely damaged by 1940s drainage projects. The current national park covers only a fifth of the original territory.

The report highlights the impact of climate change, claiming that a Celsius warming of three to four degrees would be enough to wipe out 85% of wetlands across the world.

The Pantanal, which measures 165,000 sq km (63,710 sq miles), houses hundreds of rare species, including jaguars, giant anteaters and as many as 1,100 different butterflies.

Soybean farming has been expanding in the Mato Grosso state over the last few years, helping Brazil become the world's number one soy exporter.

But this boom has also let to large swaths of land being cleared to plant new crops.