Name:
Spiraea alba var. latifolia - Cornus racemosa / Calamagrostis canadensis - Sanguisorba canadensis - Carex scoparia Seepage Shrubland
Reference:
NatureServe Biotics 2019
Description:
This saturated wetland occurs on soils weathered from Catoctin metabasalt (greenstone), a mafic metamorphic rock. The type is associated with sublevel headwater seepages on a broad summit of the northern Blue Ridge in Page and Madison counties, Virginia (vicinity of Big Meadows, Shenandoah National Park). Microtopography is typically irregular, and soils are strongly to slightly acidic, with high magnesium and iron levels and moderately low calcium content. The physiognomy of this vegetation type ranges from dense to open shrublands to wholly herbaceous but is usually a patch-mosaic of shrub thickets and herbaceous openings. <i>Spiraea alba var. latifolia</i> and <i>Cornus racemosa</i> are the typical woody dominants. In some areas, <i>Betula populifolia</i> forms a sparse tree layer 6-10 m tall. Other shrubs documented in the type are <i>Ilex verticillata, Lyonia ligustrina var. ligustrina, Aronia melanocarpa</i>, and sapling-sized <i>Acer rubrum</i>. <i>Calamagrostis canadensis, Sanguisorba canadensis</i>, and <i>Carex scoparia</i> are patch-dominant herbs common to all known occurrences of the type. Other characteristic herbaceous species are <i>Carex buxbaumii, Carex lurida, Epilobium leptophyllum, Glyceria striata, Iris versicolor, Isoetes valida, Juncus effusus var. solutus, Juncus subcaudatus var. subcaudatus, Lycopus virginicus, Oxypolis rigidior, Packera aurea, Scirpus cyperinus, Solidago rugosa</i>, and <i>Thelypteris palustris var. pubescens</i>. Herbs that are inconstant but locally abundant in the type include <i>Caltha palustris, Carex conoidea, Carex echinata ssp. echinata, Carex gynandra</i>, and <i>Menyanthes trifoliata</i>. The processes that maintain this vegetation in open condition are poorly understood. All of the documented occurrences are small and have been disturbed to some degree by grazing and/or adjacent clearing. Ditching and groundwater alterations from a large well serving the Big Meadows Campground, deer grazing, non-native weeds, woody succession, and probably fire exclusion are continuing threats to this naturally rare wetland.
Accession Code:
urn:lsid:vegbank.org:commConcept:34896-{B6FF670F-4823-475F-9C87-CC28FC436FBF}
Plot-observations of this Community Concept:
4
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