NASA satellites produce first map of global forest heights

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2010-07-25

For the first time, NASA scientists have produced a map of the height of the world's forests by combining data from three satellites.

The map will help scientists build an inventory of how much carbon the world's forests store and how fast those carbon cycles through ecosystems and back into the atmosphere.

Michael Lefsky, a remote-sensing specialist from Colorado State University in Ft. Collins, produced the final product - the first to spans the entire globe using one uniform method.

It shows the world's tallest forests are clustered in NorthAmerica's Pacific Northwest and portions of Southeast Asia, and that the shorter ones are found in broad swaths across northern Canada and Eurasia.

Lefsky used a laser technology called lidar on the ICESat that can capture vertical slices of forest canopy height by shooting pulses of light at the ground and observing how much longer it takes for light to bounce back from the surface than from the top of the forest canopy.

The new results show that temperate conifer forests have the tallest canopies (above 131 feet), boreal forests typically less than 66 feet and tropical rain forests were about 82 feet tall.

Humans release about 7 billion tons of carbon annually, mostly in the form of carbon dioxide. Of that, 3 billion tons end up in the atmosphere and 2 billion tons in the ocean.

Now, the map can help scientists understand where the remaining 2 billion tons of carbon go.

The results will be published in Geophysical Research Letters.

Source: ANI