Open-pit gold mining leaves millions of hectares of wasteland, particularly in the tropics. A series of affordable, socially inclusive and ecologically sound forest-restoration projects in Colombia could become a model for rescuing mined lands around the world.
Reforestation began in 2002 across 1,290 hectares in Cácerces, one of Colombia's most conflict-ridden regions (see L. G. Moscoso Higuita Reforestation: A Natural Process; Editorial Colina, 2005). Projects using similar techniques have since begun in other areas of the country.
First the barren landscape is reshaped using a bulldozer, and the soil is enriched with composted sewage sludge, benign microorganisms and other nutrients. Next, Acacia mangium trees are planted (because of their hardiness, fast growth and ability to improve soil by fixing nitrogen and providing abundant leaf litter), along with 10–20 native tree species.
After ten years, the A. mangium trees are logged and replaced with well-adapted native species to encourage diversity. The Cácerces site now contains more than 120 different native tree species and harbours an impressive range of wildlife, including jaguars, sloths and several species of primate.
Local people are involved in all steps of the restoration process, and they share in the social and economic benefits generated, such as increased employment and proceeds from timber sales and carbon credits. These will more than compensate for the initial investment of US$3,000 per hectare.