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Major Land Resource Area or ecological site by name and/or ID.
General information
Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
MLRA notes
Major Land Resource Area (MLRA): 131A–Southern Mississippi River Alluvium
The Southern Mississippi River Alluvium (outlined in red on the map; northern portion only) is a vast alluvial plain, stretching from the confluence of the Mississippi and Ohio Rivers to tidewater areas of the Gulf of Mexico. The area is formed primarily in sediments deposited by the Mississippi River, with significant contributions from the St Francis and Black Rivers west of Crowley’s Ridge, in the northern part of the area. A variety of alluvial landforms are present, including natural levees, sand splays, backswamps, channels, swales, stream terraces and braided terraces. Dunes have formed from wind redistribution of alluvial sands, and loess deposits overlie older terraces to the west. Elevation ranges from about 330 feet in the north to sea level in the south. Local relief is low, and much of the area appears flat, although low escarpments and other slight changes in elevation often indicate major changes in hydrology and soils.
Classification relationships
Terrestrial Natural Community Type in Missouri (Nelson, 2010):
The reference state for this ecological site is most similar to a Riverfront Forest.
Missouri Department of Conservation Forest and Woodland Communities (Missouri Department of Conservation, 2006):
The reference state for this ecological site is most similar to a Riverfront Bottomland Forest.
National Vegetation Classification System Vegetation Association (NatureServe, 2010):
The reference state for this ecological site is most similar to a Populus deltoides - Salix nigra Forest (CEGL002018).
Geographic relationship to the Missouri Ecological Classification System (Nigh & Schroeder, 2002):
This Ecological Site occurs within several Land Type Associations, primarily in the Mississippi River Alluvial Plain Subsection.
Ecological site concept
Sandy Floodplain Forests are within the green areas on the map (Missouri portion only; distributions farther south are currently under review). These areas are widely scattered in the eastern part of the area, near the current Mississippi River channel, and are most abundant in Pemiscot and southeastern Dunklin counties, Missouri. They are closely associated with Loamy Floodplain ecological sites in areas closer to the river, and with Wet Backswamp sites in Dunklin county, farther from the river. Soils are very deep and sandy. The reference plant community is forest dominated by black willow, eastern cottonwood, river birch, and sycamore.
Table 1. Dominant plant species
Tree (1) Platanus occidentalis
(2) Populus deltoidesShrub (1) Crataegus viridis
Herbaceous (1) Elymus
(2) Campanula americana
