In the Northern Great Plains, open prairies extend, unbroken, to the horizon. Amid the rolling hills and endless skies, proximity is an illusion. A team of researchers, making their way through the 800,000 hectares (2 million acres) of the Little Missouri National Grassland of North Dakota, spent countless hours clipping, separating, drying, and weighing various plains grasses during the spring and summer seasons of 2001 and 2002. The goal of this tedious undertaking was to test a new way to manage enormous pieces of land like the National Grasslands. The researchers used these ground observations to corroborate data received from a satellite sensor.
One of the investigators, Matthew Reeves of the LANDFIRE Program at the Rocky Mountain Research Station Fire Sciences Laboratory in Missoula, Montana, focused his PhD research on management applications derived from satellite technology. "There's a large interest and a big push, nowadays, to get satellite technology distilled into a format that a more general audience can use for answering strategic questions." Reeves aims to wrap this high-end technology into a comprehensible data package that land managers can apply to overseeing rangelands.
Knowing how the land is responding to pressures is key to maintaining its health and longevity. For example, if cattle herds eat all of the vegetation, the rangeland, which supplies important habitat for many species of plants and animals, will be depleted and the animals living there will eventually go hungry. In such a case, land managers seek to move the cattle before the land becomes barren; restoring it to a fertile state can take decades. Researchers have turned to Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data, archived at NASA's Land Processes Distributed Active Archive Center (LP DAAC), in hopes that it will provide large-scale land managers with a tool to help them keep the plains healthy and robust.
Soon, it may be possible for land managers to keep watch over remote acreage with the click of a mouse. From the vantage of an office, decision makers could open up a satellite image on a computer screen and find out that an isolated pasture shows signs of greening up or dying off. Analyzing the health of large landscapes can help gauge the human impact on an area and the demand for resources. By monitoring fluctuations in the vitality of rangelands, decision makers can design cohesive management strategies and modify grazing pressures accordingly. For the Bureau of Land Management and other agencies that are responsible for monitoring huge districts, using satellites to supervise large tracts of land alleviates demand for operating money and employee time.
