Ecoregions can be defined as large units of land or water containing natural communities and environmental characteristics; or certain patterns of biodiversity determined by climate, geology, and the history of the planet. The U.S. is divided into many ecoregions. Here, we will take a closer look at the ecoregions in Mississippi.
Southeastern Plains - Mostly covered in trees, these fragmentary plains have a conglomeration of woodland, pasture, cropland, and forest land cover. The most prolific vegetation in the southern portion was the longleaf pine, interspersed with smaller areas of Southern mixed forest and oak-hickory-pine. The region also has thinner loess (silty deposit of wind-blown soil) than other ecoregions to the west, and elevations and relief are greater here than in the Southern Coastal Plain. Streams found in this ecoregion are relatively low-gradient and sandy-bottomed. Sub-ecoregions found within the Southeastern Plains include:
Mississippi Alluvial Plain - This riverine ecoregion extends from Southern Illinois, at the confluence of the Ohio River with the Mississippi River, south to the Gulf of Mexico. It is within this region that the Mississippi River watershed drains all or parts of 31 states and two Canadian provinces entailing 1,243,000 square miles before the river finally reaches the Gulf of Mexico. This ecoregion is characterized mostly by a broad, flat alluvial plain with river terraces, swales and levees providing the main elements of relief. This ecoregion contains one of the largest continuous wetland systems in North America and remains a major bird migration corridor. This area also contains a large area of agricultural lands where soybeans, cotton, and rice are major crops. Sub-ecoregions within this ecoregion include:
Mississippi Valley Loess Plains - Consisting primarily of irregular plains, gently rolling hills and bluffs near the Mississippi River, this ecoregion stretches from near the Ohio River in Western Kentucky to Louisiana. Per the name, thick loess is one of this region’s distinguishing characteristics. The bluff hills in the western portion contain soils that are very deep, steep, silty, and erosive. To the east the topography is flatter, and streams tend to have less gradient and siltier substrates than in other ecoregions. In the past, the dominant natural vegetation was oak-hickory, oak-hickory-pine, and other mixed forests. This ecoregion has three sub-ecoregions found within it:
Southern Coastal Plain - This ecoregion covers a large area as it extends from South Carolina and Georgia through much of central Florida, then along the Gulf Coast lowlands of Florida, Alabama, and Mississippi. A quick glance at a map would have one believe that this area consists of mostly flat plains; however, it is a diverse region containing barrier islands, coastal lagoons, marshes, and swampy lowlands along the Gulf and Atlantic coasts. This ecoregion also contains three sub-ecoregions.
The study of our ecoregions is vital to our environment. Without these studies it would be impossible to know what is needed to ensure a secure future for not only our land and wildlife, but ourselves as well.
James L. Cummins is executive director of Wildlife Mississippi, a non-profit, conservation organization founded to conserve, restore, and enhance fish, wildlife, and plant resources throughout Mississippi. Their web site is www.wildlifemiss.org.
