Common (Translated Scientific) Name: Sweetgum - Tuliptree - (American Sycamore) / Mountain Silverbell / American Hog-peanut Floodplain Forest

Colloquial Name: Montane Sweetgum Alluvial Flat

Hierarchy Level:  Association

Type Concept: This is a low-elevation montane or submontane alluvial forest which is found on large alluvial flats and high terraces along large rivers (e.g., Little Pigeon River) or on small, disturbed flats along medium-sized perennial streams. It is found at lower elevations in the southern fringes of the Southern Blue Ridge Province, or in the adjacent Piedmont and Southern Ridge and Valley. It often occurs on sites that were formerly cleared for farming or settlement. Soils are typically deep, loamy silts but can have large rocks and cobbles. In the Great Smoky Mountains, the mean elevation of samples is 510 m (1680 feet), ranging from 450 to 580 m (1480-1900 feet). It would be possibly expected at lower elevations as well, especially in the adjacent ecoregions. This forest has an open to closed canopy dominated by Liquidambar styraciflua and Liriodendron tulipifera, often with Platanus occidentalis. It is distinguished from other kinds of Montane Alluvial Forests by the dominance or relatively higher importance of Liquidambar styraciflua in its stands, and by its habitat on larger, lower-elevation, riverine situations. Platanus is characteristic, but not necessarily dominant in stands of this association. In habitats with a more calcareous influence in the substrate, Juglans nigra may have a higher relative importance or even be codominant. The subcanopy is absent to well-developed. Typical dominants are Carpinus caroliniana, Cornus florida, and Acer rubrum. The shrub stratum is absent to moderately dense. Rhododendron maximum and Tsuga canadensis are the most common shrubs, although other species can be present. Herbaceous cover is often absent or sparse, with ground cover dominated by litter and duff. On smaller streams, near open fields or where animal grazing is evident, herbaceous cover can approach 100% cover. Species often present with high coverage include Amphicarpaea bracteata, Ageratina altissima var. altissima, Dichanthelium boscii, Thelypteris noveboracensis, and Toxicodendron radicans ssp. radicans. Stands found on small, disturbed flats along medium-sized perennial streams may contain patches of Xanthorhiza simplicissima. The exotic grass Microstegium vimineum may have high cover in some stands.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This type is distinguished from other kinds of montane alluvial forests by the dominance or relatively higher importance of Liquidambar styraciflua in its stands, and by its habitat on larger, lower elevation, riverine situations. Natural forests strongly dominated by Liquidambar styraciflua are uncommon in Southern Blue Ridge landscapes, thus this forest may represent a community that is more common at lower elevations in the southern fringes of the Southern Blue Ridge Province, or in the adjacent Piedmont and Southern Ridge and Valley. Information from a larger geographic range is needed to fully distinguish this association from related types. In Great Smoky Mountains National Park, Tennessee, this vegetation is found on the Little Pigeon River. A stand in Linville Gorge, now placed here (Newell and Peet 1995) is referred to as a "large high alluvial flat" in which Liquidambar styraciflua shares dominance. This association was initially defined from disturbed floodplains in Great Smoky Mountains National Park and is related to the more broadly defined ~Platanus occidentalis - Liriodendron tulipifera - (Betula alleghaniensis) / Alnus serrulata - Leucothoe fontanesiana Floodplain Forest (CEGL004691)$$, Montane Alluvial Forest.

Similar NVC Types: No Data Available

note: No Data Available