"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. Usi
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