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.
Gregory Asner | EurekAlert!
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
19.02.2018 | Materials Sciences
19.02.2018 | Materials Sciences
19.02.2018 | Life Sciences