Tag Archives: developing countries

The price of gold and the loss of forests

“Everything is connected” is something we say so often in ecology that it often loses its meaning. However, this new study published today in the Proceedings of the National Academy of Sciences really exemplifies the real world impact of these connections.

Skyrocketing gold prices, driven mainly by speculators, has spurred an epidemic of illegal mining (and consequently deforestation) in the Peruvian Amazon. These mines are dangerously close to a major river system, increasing the risk of mining pollution entering the Madre de Dios River watershed. Mining and deforestation often go together, as we know very well here in the UP.

Greg Asner and his colleagues used remote sensing imagery to detect these mines and measure deforestation caused by them. The images themselves provide a powerful message. Each hectare lost to mining can support hundreds of tree species, and thousands of animal species which depend upon them. The loss of these forests and risks of pollution are difficult to calculate, and therefore difficult to balance against the fluctuating value of the gold retrieved from the mines.

Losing a global carbon sponge

A paper published last week in Nature reviewed a growing body of evidence that suggests that a profound loss of forest cover in the Amazaon would have worrying consequences for the rest of the planet.

In “The Amazon basin in transition“, Davidson et al. describe how the impacts of agricultural expansion and climate events such as El Niño can conspire to destroy even more forest through drought- and fire-induced deforestation. When trees die or burn, they release carbon into the atmosphere. If more trees are destroyed than grow to replace them, more carbon is released than is absorbed; the Amazon sink becomes a source. According to the article, the Amazon rainforst currently sequesters roughly 100 billion tons of carbon, an amount equivalent to the carbon release from a decade’s worth of fossil fuel use.

Currently forest cover has been reduced to about 80% of its original area; the article suggests that if forest cover approaches 40%, a critical transition from forest to savanna may occur, given feedbacks between tree cover and precipition (see our summary in Science). If this occurs, we might witness what happens with the lost of “the lungs of the planet“.