Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

High-flying observatory reveals land changing to desert

21.12.2004


Using advanced remote-sensing techniques from a U-2 surveillance plane and field studies, scientists from the Carnegie Institution Department of Global Ecology have for the first time determined large-scale interactions between ecosystems and the climate during the process of desertification. The study, to be published in the January 2005 issue of Global Change Biology, is a milestone both for the new methods employed and for understanding what is happening as agricultural and grazing lands change into desert--a top environmental worry of the United Nations.

"Grazing is the major form of land use on the planet, with the dry, semi-arid, and sub-humid regions supporting most of it throughout the world," explained Dr. Gregory Asner, lead author at Carnegie. "Some of these regions are turning into unusable desert so quickly that the United Nations has put the problem at the top of its environmental agenda. The challenge for science--to understand what is happening to ecosystems during desertification--has been enormous because the areas are so vast it is impossible to study the processes at the field level alone. Our five-year project in the Northern Chihuahua region of New Mexico has successfully shown how the NASA Airborne Visible and Infrared Imaging Spectrometer (AVIRIS), aboard a NASA U-2, can be used to analyze the vegetation and soil changes in response to rain variation over large areas. I believe that the technique could become a standard for future global desertification studies."

Typically, remote-sensing for ecological research looks at the greenness of the top layer of vegetation, which is used to determine the amount of plant growth, or net primary production (NPP). NPP data are useful for understanding the global carbon cycle as plants breath in and lock up the greenhouse gas CO2 . NPP data, though, are not as important as are the changes in the type and distribution of vegetation as an area transitions into desert. Using the (AVIRIS), the scientists are able to analyze the physical structure of ecosystems including the live and dead plants. The data are viewed in 3-dimensions at very high resolution and can give a much broader picture of the processes at work, including carbon cycling and other chemical and biological activities.



The entire study region was about 500 square miles (800 square kilometers). Each data pixel covered an area 62 feet by 62 feet (19 meters) and looked at the ecosystem-climate interactions of grasslands, transitional terrain, and desert-shrub landscape over a five-year period. The researchers made their measurements after wintertime and summer monsoonal rains, which varied in intensity by more than 300%. "We found that a long-term decrease in litter cover is the most evident sign when an area begins to change to desert." stated Asner. "More bare soil areas and changes in green vegetation are also apparent, but they are secondary. Up to now the scientific community has focused on bare soil much more than the loss of natural litter as dry areas become desert. We also noted how the different vegetation types changed in response to the variation in rain. As areas exhibited more desert-like vegetation, there was a shift in plant responses from summer to winter precipitation events." he continued.

Dr. Christopher Field, director of the Department of Global Ecology, commented on the research: "Desertification affects the future prospects for hundreds of millions of people. Like many of the most important environmental problems of our day, desertification involves complicated interactions among climate, vegetation, and human actions. Unraveling those interactions will provide the keys to solving the problem. The techniques developed for this study open desertification and a wide range of other environmental problems to detailed analysis. I’m very excited about the potential for this work from the Department of Global Ecology to make a real difference in peoples’ futures," he concluded.

Gregory Asner | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Ecology, The Environment and Conservation:

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>