Mapping reveals targets for preserving tropical carbon stocks

An image from the Peru-wide, high-resolution carbon map showing the effects of deforestation (blue; no more carbon remaining) into a region of ultra-high carbon stocks in the surrounding forest (red). 

You can see massive losses in the bustling city of Pucallpa (right side) and the thousands of small farmers spreading into the forest to the west of Pucallpa. Image courtesy of Greg Asner. 

Credit: Greg Asner

A new high-resolution mapping strategy has revealed billions of tons of carbon in Peruvian forests that can be preserved as part of an effort to sequester carbon stocks in the fight against climate change.

Tropical forests convert more carbon from the atmosphere into biomass than any other terrestrial ecosystem on Earth.

However, when land is used for agriculture, as a wood source, or for mining, carbon is often released into the atmosphere where it contributes to climate change.

Tropical deforestation and forest degradation account for about 10 percent of the world's carbon emissions annually.

There remain major challenges to conserving the carbon that's stored in these tropical landscapes on a national and international scale.

A team led by Carnegie's Greg Asner developed a new high-resolution approach for prioritizing carbon conservation efforts throughout tropical countries.

Their findings are published the week of November 10 in the Proceedings of the National Academy of Sciences.

The team of authors emphasized that the low cost of conducting their project means that the same approach can be rapidly implemented in any country, thereby supporting both national and international commitments to reduce and offset carbon emissions.

Many of the geographic details about the carbon that's stored in tropical forest ecosystems remain unknown.

For thos involved in conservation efforts to select new areas in which carbon stocks can be best protected and enhanced, detailed information on which areas would make the best targets for protection are necessary. This means understanding each landscape's climate, topography, geology, and hydrology.

Using advanced three-dimensional forest mapping data provided by the Carnegie Airborne Observatory (CAO), integrated with satellite imaging data, the team was able to create a map of carbon density throughout the 128 million hectare (320 million acre) country of Peru, at a resolution of one hectare (2.5 acres).

"We found that nearly a billion metric tons of above-ground carbon stocks in Peru are at imminent risk for emission into the atmosphere due to land uses such as fossil fuel oil exploration, cattle ranching, oil palm plantations and gold mining," Asner said.

"The good news is that our high-resolution mapping was able to identify three strategies for offsetting these upcoming emissions."

More information: Targeted carbon conservation at national scales with high-resolution monitoring, PNAS, www.pnas.org/cgi/doi/10.1073/pnas.1419550111