Online map tracks forest shifts from space

FOREST MAP  A new tool layers satellite images onto a Google map to show changes in forest cover.

M. Hansen et al/Science 2013

By layering more than 650,000 satellite images onto a Google map, researchers have created a new tool to track forest cover.

The online tool, described in the Nov. 15 Science, lets users walk through space and time, zooming from single plots to a global view. The big picture isn’t so pretty.

From 2000 to 2012, logging, fires, storms and other disturbances wiped out 2.3 million square kilometers of forest (red). Still, the maps reveal some bright spots: Brazil has cut back on clearing rainforests. And worldwide, 800,000 square kilometers of new forest have sprung up (blue) in the U.S. Southeast, Russia and elsewhere. Green marks areas unchanged over the period; purple marks areas with both losses and gains. 

BALTIC CYCLONE In 2011, a cyclone ripped through Finland’s forests. As the storm hurtled across the Russian border, winds gouged a gash in the forest more than 160 kilometers long (red). Satellite images reveal the cyclone’s path as well as differing logging practices in the countries. In Finland, small-scale logging leaves the land evenly speckled with trees (upper left). In Russia, increased logging has not yet reached the border region, which remains cloaked in green (lower right). M. Hansen et al/Science 2013
SUMATRA RAINFOREST After decades of clear-cutting and burning upland tropical rainforests, loggers and developers in Sumatra have started clearing lowland areas too. The map above highlights the advance of forest destruction into one area of the island’s east coast. A color gradient tracks forest losses by year, from yellow in 2000 to red in 2012. May of these forests are peatland swamps that could release vast stores of carbon after being cleared. M. Hansen et al/Science 2013

Meghan Rosen is a staff writer who reports on the life sciences for Science News. She earned a Ph.D. in biochemistry and molecular biology with an emphasis in biotechnology from the University of California, Davis, and later graduated from the science communication program at UC Santa Cruz.

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