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 di
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Contact: Gregory Asner
gasner@globalecology.stanford.edu
650-380-2828
Carnegie Institution
20-Dec-2004