Seepage Forests
Seepage forests are forested wetlands typically found in dissected or undulating landscapes on side slopes, stream-head swales, ravine bottoms, or around springs on hillslopes. They have saturated soil but standing water is generally absent. These woody wetlands are fed by subsurface or groundwater seepage and occur usually on low slopes where groundwater reaches an impervious restrictive layer and seeps laterally from hill slopes.There may be small rivulets arising from springs that surface in the seepage forest and these may coalesce downslope into first-order outlet streams. Seepage forests may be gravelly or peaty and may be calcareous, circumneutral, or acidic. They often have distintive microtopographic features with numerous hummocks. A few inches in elevation gain can mean the difference between sites that support typical upland species and those that support obligate wetland species. Most modern seepage forests are relatively thickly vegetated and often contain subcanopy and shrub layers. Ferns, herbs, and sedges are often abundant in the herb layer. Bryophyte mats are common as well. Seepage forests with alkaline groundwaters are classified by some as forested fens. Many seepage slope "forests" are dominated by species that are benefitted by fire and prefer open sunlit conditions. It is quite likely that most of the modern seepage "forests" would have had a more open woodland physiognomy during presettlement times. Most are embedded in otherwise dry to xeric oak or oak-pine dominated forests and woodlands that are fire-adapted. Fires would have likely moved from these adjacent dry woodlands into and across the relatively narrow seepage communities. Exceptions to this however include high-elevation seepage forest communities in the Blue Ridge Mountains between 2,500 and 5,000 ft elevation that are associated with mesic cove-hardwood or northern-hardwood forests. In such examples fire has likely not played a significant role.
SOUTHEASTERN PLAINS
- Northern Hilly Gulf Coastal Plain Seepage Forest
- Pontotoc Ridge Seepage Forest
- Fall Line Hills Seepage Forest
- Transition Hills Seepage Forest
INTERIOR PLATEAUS
WESTERN HIGHLAND RIM ECOREGION
- Western Highland Rim Acidic Seepage Forest
- Western Highland Rim Calcareous Seepage Forest
- Western Highland Rim Streamside Seepage Forest
NASHVILLE BASIN ECOREGION
- Nashville Basin Acidic Seepage Forest
- ?
- Eastern Highland Rim Calcareous Seepage Forest
- Eastern Highland Rim Acidic Seepage Forest
- Eastern Highland Rim Acidic Seepage Flat Forest
SOUTHWESTERN APPALACHIANS
CUMBERLAND PLATEAU ECOREGION
- Cumberland Plateau Acidic Seepage Forest
CRAB ORCHARD MOUNTAINS
- Crab Orchard Mountains Acidic Seepage Forest
SEQUATCHIE VALLEY ECOREGION
- ?
CENTRAL APPALACHIANS
CUMBERLAND MOUNTAINS
- Cumberland Mountains Acidic Seepage Forest
CUMBERLAND MOUNTAIN THRUSTBLOCK ECOREGION
- Cumberland Mountain Thrustblock Acidic Seepage Forest
RIDGE AND VALLEY
SOUTHERN CALCAREOUS VALLEYS ECOREGION
- Ridge and Valley Calcareous Seepage Forest
SHALE VALLEYS ECOREGION
- ?
DISSECTED RIDGES ECOREGION
- ?
SANDSTONE RIDGES ECOREGION
- Ridge and Valley Acidic Seepage Forest
BLUE RIDGE MOUNTAINS
SEDIMENTARY MOUNTAINS ECOREGION
- Blue Ridge Sedimentary Mtns Floodplain Seepage Forest
- Blue Ridge Sedimentary Mtns Acidic Seepage Forest
HIGH MOUNTAINS ECOREGION
- Blue Ridge Metasedimentary High Mountains High-Elevation Seepage Forest
- Blue Ridge Metasedimentary High Mountains High-Elevation Boulderfield Seepage Forest
- Blue Ridge Igneous High Mountains High-Elevation Boulderfield Seepage Forest
METASEDIMENTARY MOUNTAINS ECOREGION
- Blue Ridge Metasedimentary Mtns Floodplain Seepage Forest
- Blue Ridge Metasedimentary Mtns Acidic Seepage Forest
- Blue Ridge Metasedimentary Mtns Low-Mid Elevation Base-Rich Seepage Forest
- Blue Ridge Mid-High Elevation Base-Rich Seepage Forest
MONTANE BASINS ECOREGION
- Blue Ridge Montane Basins Acidic Seepage Forest
- Blue Ridge Montane Basins Floodplain Seepage Forest
IGNEOUS MOUNTAINS ECOREGION
- Blue Ridge Igneous Mtns Low-Elevation Igneous Acidic Seepage Forest
- Blue Ridge Igneous Mtns Low-Elevation Acidic Floodplain Seepage Forest
AMPHIBOLITE MOUNTAINS ECOREGION
- Blue Ridge Amphibolite Mountains Mid-High Elevation Seepage Forest
DOLOMITE COVES ECOREGION
- Blue Ridge Dolomite Coves Calcareous Seepage Forest
- Blue Ridge Dolomite Coves Acidic Floodplain Seepage Forest