Along a swath of land curving through Mississippi and Alabama, farms dominate the landscape. The region is known as the Black Belt Prairie, so named for its characteristically dark, fertile soil. The contrast between this cultivated land and the surrounding forested areas is so stark that it is visible from space.
The crescent shape of the Black Belt shows up in a natural-color image (above) by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. The image is a “best-pixel mosaic,” which means it is composed of small parts of many images captured between 2015 and 2018. The technique makes it possible to strip away clouds and haze.
“The open, relatively treeless nature of the Black Belt makes it stand out amongst the adjacent forested landscapes in Mississippi and Alabama,” said JoVonn Hill of Mississippi State University, who studies the biodiversity of grasslands in the southeastern United States. “One visiting the Black Belt today would likely see lots of agricultural fields filled with corn, cotton, and soybeans, as well as cattle production.”
Indeed, cultivated land dominates the Black Belt as indicated by green areas in the map below, based on 2011 data from the National Land Cover Database (NLCD). Built from Landsat satellite images, the NLCD distinguishes between types of land cover (urban, forested, farmed, etc.).
The fertile soil has origins in the Cretaceous Period, when the shoreline of the Gulf of Mexico was much farther inland. Over millions of years, plankton that lived in the Gulf left behind exoskeletons rich in calcium carbonate—the accumulation of which resulted in the Black Belt’s chalk subsoil. As a result of all the calcium, the soil is very fertile and good for growing crops.
Before farmers discovered the soil’s fertility, the Black Belt was primarily prairie. According to Hill, about 356,000 acres of prairie were documented in the Black Belt in the 1830s. Estimates suggest that less than 1 percent of these prairies remain today. Find a remnant of the Black Belt prairie, Hill notes, and you could see some of its unique grassland birds; more than 200 species of plants, 1,000 species of moths, 107 species of bees, 33 species of grasshoppers, and 53 species of ants.
“The Black Belt Prairie has a rich biological and cultural history, which went ignored for a long time,” Hill said. “Currently, groups like the Southeastern Grasslands Initiative are working to draw awareness to natural grasslands in the southeastern United States so that they may be conserved for future generations.”
NASA Earth Observatory images by Joshua Stevens, using data from the Level 1 and Atmospheres Active Distribution System (LAADS) and Land Atmosphere Near real-time Capability for EOS (LANCE), and land cover data from the National Land Cover Database. Story by Kathryn Hansen with image interpretation by JoVonn Hill/Mississippi State University.