The remnants of America’s tallgrass prairies are going up in flames, but that’s a good thing. Fire kills trees and shrubs that constantly threaten to overwhelm the grasslands. NASA’s Earth Observatory recently featured satellite images of the controlled burns started in late March by the Kansas Forest Service to help preserve the prairies.
In an image from March 29 (above), red outlines and wisps of smoke mark where fires torch the grass in preparation for spring’s rejuvenation. Dark patches of scorthed earth resulted from earlier burns. An false color image from two days later (below) shows the results of the burns as brownish-red scars with surrounding crop and pasture in light green.
Less that 4 percent remains of the tallgrass prairies that once covered the heart of North America from Manitoba, Canada and Montana in the north to central Texas in the south. In the past, fires may started by Native Americans or lightning strikes renewed the grasslands and kept forests at bay. Massive herds of bison also helped to prune away tree saplings.
However, as European and American settlers moved into the plains, crops replaced the grasses and cattle replaced the bison. Now, land mangers must replicate nature and start controlled fires to keep the tattered shreds of the prairie from disappearing entirely. Eastern Kansas and the Flint Hills of Oklahoma harbor most of the remaining tallgrass prairie in the United States.
Fire wipes out young trees and some invasive species. Blazes also restore nutrients and expose soil to sunlight. The soft, new grass that pops up makes a tender, nutrient-rich salad for plant-eating animals, including cattle that the U.S. food system depends upon.
Photo: NASA images courtesy Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC.