Go back

Blue Ridge Sedimentary Mtns Sandstone Streambed

Synonyms

South-Central Interior Small Stream & Riparian Ecological System (NatureServe 2015)

Southern Appalachian Seepage Wetland Ecological System (NatureServe 2015)

Southern and Central Appalachian Cove Forest Ecological System (NatureServe 2015)

Distribution

Blue Ridge Mountains in the Sedimentary Mountains Ecoregion of northeast Tennessee. It is possible the same association of dominants probably occurs in other ecoregions (Metasedimentary Mountains Ecoregion, Igneous Mountains Ecoregion, Amphibolite Mountains Ecoregion) in northeast TN, northwest NC, and southwest VA.

Vegetation Description

Leafy forbs, sedges, grasses, and occasionally ferns, dominate this small patch community and vegetation height ranges from 0.25 – 1.5 m. Scattered shrubs and tree saplings may be present.

Physical Characterization

This community, strictly defined, occurs in the Sedimentary Mountains Ecoregion  (Estes & Fleming 2015) of northeast Tennessee's Blue Ridge physiographic province. It occurs in or immediately adjacent to the beds of mid- to high-elevation small streams at elevations ranging from ___-___ m (3,700-4,200 ft). These are headwater streams with strong to moderate gradient and lack adjacent alluvial zones or distinct riparian vegetation. Stream depth is shallow and less than a few centimeters or reduced to a trickle over bedrock to a few decimeters in deeper pools among accumulations of cobble and boulder. The bedrock geology of the stream is formed of Cambrian-aged sandstone of the Unicoi Formation, predominantly with possible minor amounts of arkose, graywacke. Farther upslope at higher elevations the bedrock geology is pre-Cambrian igneous rocks of the Mount Rogers Group, which mostly consists of metavolcaics, massive lavas and tuffs, and altered rhyolites. It also includes a complex array of other rocks, some of which are base-rich mafic rocks (gabbro, diorite, basalt, anorthosite, diabase granite, migmatite, granitic gneisses, monzonite, quartz diorite, greenstone, mica and hornblende schists, granitic pegmatite; gneiss, hornblende, mica schist, amphibolite).

Soils....

Soil series involved:

  • BeC- Bewleyville silt loam, 5-12 percent slopes
  • Gu - Guthrie Silt Loam

Natural Processes

This seepage vegetation is maintained by the combination of the in-channel flow of the stream as well as seepage from adjacent slopes that feed the stream channel. Seeps vegetation develops on the shallow areas over bedrock of small accumulations of rubble. The combination of shallow substrate and periodic high flow of the stream prevents larger shrubs and trees from establishing in favor of herb development. The base-rich nature of this seep type presumably is related to the high base-rich mineral composition of mafic rocks of the usptream igneous rocks and the high amount of igneous rubble in the stream. 

Dominant Plants

Herbaceous Layer: Ageratina altissima var. roanensis (Roan Mountain snakeroot), Carex scabrata (eastern rough sedge), Chelone glabra (white turtlehead), Dryopteris intermedia (intermediate woodfern), Houstonia serpyllifolia (thymeleaf bluets), Impatiens capensis (spotted jewelweed), Laportea canadensis (wood nettle), Micranthes micranthifolia (brook saxifrage), Monarda didyma (scarlet bee balm), Packera aurea (golden ragwort), Poa alsodes (grove bluegrass), Viola cucullata (marsh blue violet)

Characteristic Plants

Restricted or Noteworthy Plants

Scutellaria saxatilis (smooth rock skullcap)

Invasive Species

none documented

Community Variation and Subtypes

This community is similar to the Rich Montane Seep listed below. With that seep type it is similar in the presence of lettuceleaf saxifrage and woodnettle and it shares a number of species in common. However, Diphylleia cymosa, a diagnostic species for the seep type below does not occur in the northern Blue Ridge in this seep type. Other notable elements, such as Euonymus obovatus, are also absent.

CEGL004296 Diphylleia cymosa - Saxifraga micranthidifolia - Laportea canadensis Herbaceous Vegetation
G3
Rich Montane Seep (Cove Type)
American Umbrella-leaf - Lettuceleaf Saxifrage - Canadian Woodnettle Herbaceous Vegetation

Synonyms

South-Central Interior Small Stream & Riparian Ecological System (NatureServe 2015)

Southern Appalachian Seepage Wetland Ecological System (NatureServe 2015)

Southern and Central Appalachian Cove Forest Ecological System (NatureServe 2015)

Distribution

Blue Ridge Mountains in the Sedimentary Mountains Ecoregion of northeast Tennessee. It is possible the same association of dominants probably occurs in other ecoregions (Metasedimentary Mountains Ecoregion, Igneous Mountains Ecoregion, Amphibolite Mountains Ecoregion) in northeast TN, northwest NC, and southwest VA.

Vegetation Description

Leafy forbs, sedges, grasses, and occasionally ferns, dominate this small patch community and vegetation height ranges from 0.25 – 1.5 m. Scattered shrubs and tree saplings may be present.

Physical Characterization

This community, strictly defined, occurs in the Sedimentary Mountains Ecoregion  (Estes & Fleming 2015) of northeast Tennessee's Blue Ridge physiographic province. It occurs in or immediately adjacent to the beds of mid- to high-elevation small streams at elevations ranging from ___-___ m (3,700-4,200 ft). These are headwater streams with strong to moderate gradient and lack adjacent alluvial zones or distinct riparian vegetation. Stream depth is shallow and less than a few centimeters or reduced to a trickle over bedrock to a few decimeters in deeper pools among accumulations of cobble and boulder. The bedrock geology of the stream is formed of Cambrian-aged sandstone of the Unicoi Formation, predominantly with possible minor amounts of arkose, graywacke. Farther upslope at higher elevations the bedrock geology is pre-Cambrian igneous rocks of the Mount Rogers Group, which mostly consists of metavolcaics, massive lavas and tuffs, and altered rhyolites. It also includes a complex array of other rocks, some of which are base-rich mafic rocks (gabbro, diorite, basalt, anorthosite, diabase granite, migmatite, granitic gneisses, monzonite, quartz diorite, greenstone, mica and hornblende schists, granitic pegmatite; gneiss, hornblende, mica schist, amphibolite).

Soils....

Soil series involved:

Natural Processes

This seepage vegetation is maintained by the combination of the in-channel flow of the stream as well as seepage from adjacent slopes that feed the stream channel. Seeps vegetation develops on the shallow areas over bedrock of small accumulations of rubble. The combination of shallow substrate and periodic high flow of the stream prevents larger shrubs and trees from establishing in favor of herb development. The base-rich nature of this seep type presumably is related to the high base-rich mineral composition of mafic rocks of the usptream igneous rocks and the high amount of igneous rubble in the stream. 

Dominant Plants

Herbaceous Layer: Ageratina altissima var. roanensis (Roan Mountain snakeroot), Carex scabrata (eastern rough sedge), Chelone glabra (white turtlehead), Dryopteris intermedia (intermediate woodfern), Houstonia serpyllifolia (thymeleaf bluets), Impatiens capensis (spotted jewelweed), Laportea canadensis (wood nettle), Micranthes micranthifolia (brook saxifrage), Monarda didyma (scarlet bee balm), Packera aurea (golden ragwort), Poa alsodes (grove bluegrass), Viola cucullata (marsh blue violet)

Characteristic Plants

Restricted or Noteworthy Plants

Scutellaria saxatilis (smooth rock skullcap)

Invasive Species

none documented

Community Variation and Subtypes

This community is similar to the Rich Montane Seep listed below. With that seep type it is similar in the presence of lettuceleaf saxifrage and woodnettle and it shares a number of species in common. However, Diphylleia cymosa, a diagnostic species for the seep type below does not occur in the northern Blue Ridge in this seep type. Other notable elements, such as Euonymus obovatus, are also absent.

CEGL004296 Diphylleia cymosa - Saxifraga micranthidifolia - Laportea canadensis Herbaceous Vegetation
G3
Rich Montane Seep (Cove Type)
American Umbrella-leaf - Lettuceleaf Saxifrage - Canadian Woodnettle Herbaceous Vegetation


Associated Natural Communities

Blue Ridge Mountains Sedimentary Mountains Dry/Submesic Mid-Elevation Acid Forest, Blue Ridge Mountains Sedimentary Mountains Mesic Mid-Elevation Acid Forest

Similar Communities

Presettlement Distribution and Size

This small-patch seepage community likely has remained nearly intact compared to its pre-settlement extent and composition. Adjacent logging and stream siltation do not presently pose threats to this community but during past periods of heavy logging this community was probably affected. Most examples are protected within the Cherokee National Forest.

Present Status

This community should be considered secure in Tennessee.

Representative Sites


Threats

No active threats.

Management Considerations

No management recommendations.

Future Research Needs

Continued floristic research, plotwork, and vegetation mapping are needed for this community.

Previous Studies



Associated Natural Communities

Blue Ridge Mountains Sedimentary Mountains Dry/Submesic Mid-Elevation Acid Forest, Blue Ridge Mountains Sedimentary Mountains Mesic Mid-Elevation Acid Forest

Similar Communities

Presettlement Distribution and Size

This small-patch seepage community likely has remained nearly intact compared to its pre-settlement extent and composition. Adjacent logging and stream siltation do not presently pose threats to this community but during past periods of heavy logging this community was probably affected. Most examples are protected within the Cherokee National Forest.

Present Status

This community should be considered secure in Tennessee.

Representative Sites


Threats

No active threats.

Management Considerations

No management recommendations.

Future Research Needs

Continued floristic research, plotwork, and vegetation mapping are needed for this community.

Previous Studies


References

Geology available at Tennesse Spatial Data Server which can be found at http://www.tngis.org/geology.html which links to a USGS Water Resources Division site: http://water.usgs.gov/lookup/getspatial?geo250k Tennessee Spatial Data Server site notes: Thanks goes to Jim Julian for researching this improved geology layer from the Tennessee Division of Geology. **Note** - The Tennessee Division of Geology does not endorse this coverage, stating this version is still incomplete and not fit for distribution.

NatureServe. 2014. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed: March 1, 2015).

Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at http://websoilsurvey.nrcs.usda.gov/. Accessed [02/25/2015].

USNVC [United States National Vegetation Classification]. 2016. United States National Vegetation Classification Database, V2.0. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. [usnvc.org] (accessed 27 Dec 2016)

Floristic Checklist 

List compiled by surveys by D. Rodgers, C. Mausert-Mooney, and D. Estes


References

Geology available at Tennesse Spatial Data Server which can be found at http://www.tngis.org/geology.html which links to a USGS Water Resources Division site: http://water.usgs.gov/lookup/getspatial?geo250k Tennessee Spatial Data Server site notes: Thanks goes to Jim Julian for researching this improved geology layer from the Tennessee Division of Geology. **Note** - The Tennessee Division of Geology does not endorse this coverage, stating this version is still incomplete and not fit for distribution.

NatureServe. 2014. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed: March 1, 2015).

Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at http://websoilsurvey.nrcs.usda.gov/. Accessed [02/25/2015].

USNVC [United States National Vegetation Classification]. 2016. United States National Vegetation Classification Database, V2.0. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. [usnvc.org] (accessed 27 Dec 2016)

Floristic Checklist 

List compiled by surveys by D. Rodgers, C. Mausert-Mooney, and D. Estes