Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First-of-Its-Kind Map Details the Height of the Globe’s Forests

21.07.2010
Using satellite data, scientists have produced a first-of-its kind map that details the height of the world’s forests. Although there are other local- and regional-scale forest canopy maps, the new map is the first that spans the entire globe based on one uniform method.
The map, based on data collected by NASA's ICESat, Terra, and Aqua satellites, should help scientists build an inventory of how much carbon the world’s forests store and how fast that carbon cycles through ecosystems and back into the atmosphere.

This new global depiction shows the world’s tallest forests clustered in the Pacific Northwest of North America and portions of Southeast Asia, while shorter forests are found in broad swaths across northern Canada and Eurasia. Temperate conifer forests – which are extremely moist and contain massive trees such as Douglas fir, western hemlock, redwoods, and sequoias – have the tallest canopies, soaring easily above 40 meters (131 feet). In contrast, boreal forests dominated by spruce, fir, pine, and larch had canopies typically less than 20 meters (65 feet). Relatively undisturbed areas in tropical rain forests were about 25 meters (82 feet), roughly the same height as the oak, beeches, and birches of temperate broadleaf forests common in Europe and much of the United States.

“This is a really just a first draft, and it will certainly be refined in the future,” said Michael Lefsky, the remote sensing specialist from Colorado State University who made the map. Lefsky described his results in a scientific report that has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

The forest-height map has implications for an ongoing effort to estimate the amount of carbon tied up in Earth’s forests and for explaining what sops up 2 billion tons of “missing” carbon each year. 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. It’s unclear where the last two billion tons of carbon go, though scientists suspect forests capture and store much of it as biomass through photosynthesis.

“What we really want is a map of above-ground biomass, and the height map helps get us there,” said Richard Houghton, an expert in terrestrial ecosystem science and the deputy director of the Woods Hole Research Center.

Lefsky used data from a laser technology called LIDAR that’s capable of capturing vertical slices of surface features. It does so by shooting pulses of light at the surface and observing how much longer it takes for light to bounce back from the ground surface than from the top of the canopy. Since LIDAR can penetrate the top layer of forest canopy, it provides a fully-textured snapshot of the vertical structure of a forest—something that no other scientific instrument can offer.

Lefsky based his map on data from more than 250 million laser pulses collected during a seven-year period. Each pulse returns information about just a tiny portion of the Earth’s surface, so the project completed direct LIDAR measurements of only 2.4 percent of the planet’s forested surfaces. To complete the map, Lefsky combined the LIDAR data with information from the Moderate Resolution Imaging Spectroradiometer (MODIS), a satellite instrument aboard both the Terra and Aqua satellites that senses a much broader swath of Earth’s surface, even though it doesn’t provide the vertical profile.

The next generation LIDAR measurements of forests and biomass, which will improve the resolution of the map considerably, could come from NASA's Deformation, Ecosystem Structure and Dynamics of Ice (DESDynI) satellite, proposed for the latter part of this decade.
Notes for Journalists
As of the date of this press release, the paper by Lefsky is still “in press” (i.e. not yet published). Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this paper in press by clicking on this link:

http://www.agu.org/journals/pip/gl/2010GL043622-pip.pdf

Or, you may order a copy of the paper by emailing your request to Kathleen O’Neil at koneil@agu.org. Please provide your name, the name of your publication, and your phone number. Neither the paper nor this press release are under embargo.

Title: “A global forest canopy height map from MODIS and the Geoscience Laser Altimeter System”

Author: Michael Lefsky, Colorado State University, Fort Collins, Colorado, USA.

Contact information for the author: Michael Lefsky +1(970) 491-0602; lefsky@cnr.colostate.edu

AGU Contact: Kathleen O’Neil +1 (202) 777-7524, koneil@agu.org
NASA Contact: Steven Cole +1 (202) 358-0918, stephen.e.cole@nasa.gov
CSU Contact: Kimberly Sorensen +1 (970) 491-0757 kimberly.sorensen@colostate.edu

Kathleen O’Neil | American Geophysical Union
Further information:
http://www.agu.org

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>