Go back

Flatwoods

Flatwoods represent a type of wooded wetland. They are found in numeorus ecoregions across Tennessee but are most prevalent in Middle and West Tennessee where they are associated with very flat landforms such as plateau surfaces, basins, and high terraces of wide alluvial plains. These woodlands are developed over clay-soils that are underlain by a clay fragipan (hardpan). The restrictive nature of the fragipan prevents the drainage of water in winter and spring such that flatwoods soils are saturated and ponding of water is common, resulting in shallow vernal pools. In summer and fall, the shallow soils above the fragipan often become very dry. This alternation between wet and dry regimes (called hydroxeric) allows for the development a distinctive herb layer in flatwoods. Spring herbs are often dependent on the ephemeral pools and saturated conditions whereas summer/fall herbs depend on very dry conditions. Fire is naturally important in flatwoods communities. Often with high fire frequencies, flatwoods attain an open canopy with a grassy herb layer. Some flatwoods communities historically may have been more savanna-like. Nearly all present-day examples are fire suppressed and in need of a combination of stand-thinning and increased fire. The flatwoods ecosystem of the southern Eastern Highland Rim is the single most species rich ecosystem in Tennessee in terms of vascular plants.

MISSISSIPPI ALLUVIAL PLAIN

PLEISTOCENE VALLEY TRAIN ECOREGION

  • Mississippi Alluvial Plain Pleistocene Valley Train Flatwoods

MISSISSIPPI VALLEY LOESS PLAINS

LOESS PLAIN ECOREGION

SOUTHEASTERN PLAINS


BLACK BELT ECOREGION

  • Black Belt Flatwoods
FLATWOODS ECOREGION

  • Flatwoods Flatwoods
NORTHERN HILLY GULF COASTAL PLAIN ECOREGION
  • Northern Hilly Gulf Coastal Plain Valley Flatwoods
  • Northern Hilly Gulf Coastal Plain Upland Flatwoods

INTERIOR PLATEAUS

WESTERN HIGHLAND RIM ECOREGION

PENNYROYAL PLAIN ECOREGION

NASHVILLE BASIN ECOREGION

GREENSBURG UPLANDS ECOREGION

  • Greensburg Uplands Flatwoods
EASTERN HIGHLAND RIM ECOREGION

SOUTHWESTERN APPALACHIANS

CUMBERLAND PLATEAU ECOREGION

SEQUATCHIE VALLEY ECOREGION

RIDGE AND VALLEY

SOUTHERN CALCAREOUS VALLEYS ECOREGION

SHALE VALLEYS ECOREGION