Gold mining has gobbled up some 1,680 square kilometres (650 square miles) of tropical forest in South America in the 13 years to 2013, a research paper said Wednesday.

Much of the loss happened near conservation areas, placing protected zones at risk from chemical pollutants used in mining, said the study in the journal Environmental Research Letters.

The findings "highlighted the growing environmental impact of gold mining in some of the most biologically diverse regions in the tropics," said a press statement.

"Although the loss of forest due to mining is smaller in extent compared to deforestation caused by other land uses, such as agriculture or grazing areas, deforestation due to mining is occurring in some of the most biologically diverse regions," said study author Nora Alvarez-Berrios of the University of Puerto Rico.

"For example, in the Madre de Dios region in Peru, one hectare of forest can hold up to 300 species of trees."

Global gold production increased from about 2,445 metric tons in 2000 to 2,770 in 2013. The price of gold rose from $250 an ounce (212 euros in today's price) to $1,300 an ounce over the same period.

"This has stimulated new gold mining activities around the world and made it feasible to mine for gold in areas that were not previously profitable for mining, such as deposits underneath tropical forests," said the statement.

The study looked at forests in Colombia, Venezuela, Guyana, Suriname, french Guyana, Brazil, Ecuador, Peru and Bolivia.

On the sidelines of UN climate talks in Lima in December, seven Latin American countries pledged to replant nearly 20 million hectares of forest by 2020.

Forests are crucial carbon "sinks", their trees sucking up Earth-warming CO2 emitted into the atmosphere by mankind's fossil fuel burning. Several million square kilometres of forest land is lost globally every year.