Name:
Picea rubens - Abies fraseri Forest Alliance
Reference:
NatureServe Biotics 2019
Description:
Canopies can be dominated by <i>Abies fraseri</i> and/or <i>Picea rubens</i>; <i>Betula alleghaniensis</i> and other northern hardwood species may be codominant in mixed stands. Canopy/subcanopy species of minor importance can include <i>Acer spicatum, Acer pensylvanicum, Amelanchier laevis, Betula alleghaniensis, Prunus pensylvanica</i>, and <i>Sorbus americana</i>. Forests on extreme sites may have an open canopy, with stunted appearance and, in some communities, standing dead stems of <i>Abies fraseri</i> are common, with extensive patches of <i>Abies fraseri</i> seedlings in canopy gaps. The density and composition of the shrub and herbaceous strata vary among associations in this alliance. Forests in this alliance typically have a well-developed bryophyte layer. Mosses, liverworts, and lichens grow densely on fallen logs, tree trunks, and the forest floor, giving these forests a distinctive carpeted appearance. This alliance contains many species endemic to the Southern Blue Ridge or that have the bulk of their worldwide range in that region. This vegetation is restricted to the highest mountain systems of the Southern Blue Ridge, in eastern Tennessee, western North Carolina, and southwestern Virginia, as well as outliers in the Central Appalachians of West Virginia, primarily within the distributional range of <i>Abies fraseri</i>. These forests occur on all topographic positions except the steepest rocky cliffs. Elevations range from 1350-2300 m (4400-6600 feet), with pure <i>Abies fraseri</i> associations best developed above 1830 m (6000 feet). The dominant soils are Inceptisols with scattered occurrences of Spodosols at the highest elevations. Generally, soils can be described as rocky, with well-developed organic and A horizons. All soils in these high-elevation forests are low in base saturation, high in organic matter, and are acidic in reaction (pH 3-5), with a high aluminum content. The moisture regimes of these areas are mesic to wet due to high rainfall, abundant cloud cover, fog deposition, and low temperatures. The climate has been classified as perhumid, with the temperature varying elevationally from mesothermal to microthermal. The regional geology is dominated by complexly folded metamorphic, sedimentary, and igneous rocks of the Precambrian and early Paleozoic age, including phyllites, slates, schists, sandstones, quartzites, granites, and gneisses. These forests are affected by debris avalanches, wind and ice disturbance, and lightning fire. Because of the rocky soils and extreme wind exposure, these forests are susceptible to large blowdowns, particularly in areas damaged by the invasive balsam woolly adelgid (<i>Adelges piceae</i>).
Accession Code:
urn:lsid:vegbank.org:commConcept:38021-{C748E2DF-2703-4672-B7F4-5423D7D0A682}
Plot-observations of this Community Concept:
0
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