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CEGL008529 Fraxinus americana / Physocarpus opulifolius / Carex pensylvanica - Allium cernuum - (Phacelia dubia) Wooded Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: White Ash / Common Ninebark / Pennsylvania Sedge - Nodding Onion - (Small-flower Phacelia) Wooded Grassland
Colloquial Name: Central Appalachian Mafic Barrens (Ninebark / Pennsylvania Sedge Type)
Hierarchy Level: Association
Type Concept: This community is known only from the northern Virginia Blue Ridge and possibly the higher adjacent foothills, in areas underlain by Catoctin metabasalt (greenstone) and Middle Proterozoic plutonic rocks. Sites are located on steep (up to 37°), xeric, middle-elevation slopes where exposed outcrops effectively limit the establishment and normal development of trees. Underlying bedrock at most sites is metabasalt (greenstone). Three documented sites are underlain by charnockite, a pyroxene-bearing granitic rock, and it is likely that additional stands occur on this and related plutonic formations. Elevation of plot-sampled stands ranges from 543 to 1050 m (1782-3450 feet), with a mean of 835 m (2740 feet). Middle-slope topographic positions are typical, with slopes convex in at least one direction. Aspect varies from southeast to northwest, with westerly aspects prevalent. This vegetation type is dominated by herbaceous plants with scattered shrub patches and stunted trees. The herb layer usually ranges from 25-60% total cover (occasionally higher or lower), and from scattered to locally dense where soil and organic matter have accumulated. Carex pensylvanica and Schizachyrium scoparium are consistently dominant herbs. Phacelia dubia is an abundant spring ephemeral in about two-thirds of the plots, and this species may have been missed in late-season sampling of other plots.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Although this community type has been referred to as a "greenstone glade" (Fleming 1993), this name is inappropriate given the occasional occurrence of the type on granitic rocks. Additional inventory and data collection are needed to determine the extent of this association on plutonic substrates. This community often occurs adjacent to, or nested within, a larger patch of ~Fraxinus americana - Carya glabra / Muhlenbergia sobolifera - Helianthus divaricatus - Solidago ulmifolia Woodland (CEGL003683)$$. It is also similar to ~Juniperus virginiana - Fraxinus americana / Carex pensylvanica - Cheilanthes lanosa Open Woodland (CEGL006037)$$, which occurs at lower elevations, on a wider variety of substrates (including calcareous shales), and has a large component of elevation-limited lithophytes absent from this association (CEGL008529).
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This vegetation type is dominated by herbaceous plants with scattered shrub patches and stunted trees. The herb layer usually ranges from 25-60% total cover (occasionally higher or lower), and from scattered to locally dense where soil and organic matter have accumulated. Carex pensylvanica and Schizachyrium scoparium are consistently dominant herbs. Phacelia dubia is an abundant spring ephemeral in about two-thirds of the plots, and this species may have been missed in late-season sampling of other plots. Other relatively frequent (>50% constancy) herbs are Agrostis perennans, Allium cernuum, Ambrosia artemisiifolia, Danthonia spicata, Dichanthelium acuminatum, Elymus hystrix, Helianthus divaricatus, Hylotelephium telephioides (= Sedum telephioides), and Polygonatum biflorum. Deschampsia flexuosa, Festuca rubra, and Symphyotrichum laeve var. concinnum (= Aster laevis var. concinnus) are each common locally. Herbaceous species that are characteristic of gravelly or mossy crevices and depressions with ephemeral spring seepage or periodic moisture accumulation include Draba ramosissima, Muhlenbergia glomerata, Polygonum tenue, Saxifraga virginiensis, Phemeranthus teretifolius (= Talinum teretifolium), and Woodsia ilvensis. Stunted trees (<10 m tall) of Fraxinus americana are consistent features of the community type. Physocarpus opulifolius and Rosa carolina are the most frequent shrubs, but Chionanthus virginicus, Rhus typhina, Juniperus virginiana, Amelanchier sanguinea, Ptelea trifoliata, and Spiraea alba var. latifolia are each important in a subset of plots. Species richness of plot-sampled stands ranges from 28 to 58 taxa per 400 m2 (mean = 40).
Dynamics: No Data Available
Environmental Description: Sites are located on steep (up to 37°), xeric, middle-elevation slopes where exposed outcrops effectively limit the establishment and normal development of trees. Underlying bedrock at most sites is metabasalt (greenstone). Three documented sites are underlain by charnockite, a pyroxene-bearing granitic rock, and it is likely that additional stands occur on this and related plutonic formations. Elevation of plot-sampled stands ranges from 543 to 1050 m (1782-3450 feet), with a mean of 835 m (2740 feet). Middle-slope topographic positions are typical, with slopes convex in at least one direction. Aspect varies from southeast to northwest, with westerly aspects prevalent. Surface cover of exposed outcrops and loose rocks averages >50% and soil development is limited to depositional crevices and thin veneers on ledges. Soil samples collected from plots are very strongly acidic (mean pH = 4.5), with substantial organic matter content (mean = 26%), but have moderately high levels of calcium (mean = 1185 ppm) and magnesium (mean = 174 ppm).
Geographic Range: This community is known only from the northern Virginia Blue Ridge and possibly the higher adjacent foothills, in areas underlain by Catoctin metabasalt (greenstone) and Middle Proterozoic plutonic rocks.
Nations: US
States/Provinces: VA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.688917
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G2
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.B Temperate & Boreal Grassland & Shrubland Subclass | S18 | 2.B |
| Formation | 2.B.2 Temperate Grassland & Shrubland Formation | F012 | 2.B.2 |
| Division | 2.B.2.Nc Eastern North American Grassland & Shrubland Division | D024 | 2.B.2.Nc |
| Macrogroup | 2.B.2.Nc.1 Catawba Rosebay / Michaux''s Saxifrage - Flattened Oatgrass Felsic & Mafic Scrub & Grassland Macrogroup | M506 | 2.B.2.Nc.1 |
| Group | 2.B.2.Nc.1.c Little Bluestem - Balsam Groundsel - Prairie Groundsel Appalachian Mafic Glade Group | G180 | 2.B.2.Nc.1.c |
| Alliance | A2074 White Ash - Post Oak / Pennsylvania Sedge Appalachian Mafic-Circumneutral Scrub Alliance | A2074 | 2.B.2.Nc.1.c |
| Association | CEGL008529 White Ash / Common Ninebark / Pennsylvania Sedge - Nodding Onion - (Small-flower Phacelia) Wooded Grassland | CEGL008529 | 2.B.2.Nc.1.c |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Fraxinus americana / Physocarpus opulifolius / Carex pensylvanica - Allium cernuum - (Phacelia dubia) Wooded Herbaceous Vegetation (Fleming and Coulling 2001)
= Fraxinus americana / Physocarpus opulifolius / Carex pensylvanica - Allium cernuum Wooded Herbaceous Vegetation (Young et al. 2007a)
< Greenstone glade (Fleming 1993)
= Fraxinus americana / Physocarpus opulifolius / Carex pensylvanica - Allium cernuum Wooded Herbaceous Vegetation (Young et al. 2007a)
< Greenstone glade (Fleming 1993)
- Fleming, G. P. 1993. Floristics and preliminary classification of greenstone glade vegetation in Virginia. Virginia Journal of Science 44:119 (Abstract).
- Fleming, G. P., A. Belden, Jr., K. E. Heffernan, A. C. Chazal, N. E. Van Alstine, and E. M. Butler. 2007a. A natural heritage inventory of the rock outcrops of Shenandoah National Park. Unpublished report submitted to the National Park Service. Natural Heritage Technical Report 07-01. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond. 433 pp. plus appendixes.
- Fleming, G. P., K. D. Patterson, and K. Taverna. 2017. The natural communities of Virginia: A classification of ecological community groups and community types. Third approximation. Version 3.0. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond, VA. [http://www.dcr.virginia.gov/natural-heritage/natural-communities/]
- Fleming, G. P., and K. D. Patterson. 2009b. Classification of selected Virginia montane wetland groups. In-house analysis, December 2009. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond.
- Fleming, G. P., and P. P. Coulling. 2001. Ecological communities of the George Washington and Jefferson national forests, Virginia. Preliminary classification and description of vegetation types. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond, VA. 317 pp.
- Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.
- Young, J., G. Fleming, P. Townsend, and J. Foster. 2006. Vegetation of Shenandoah National Park in relation to environmental gradients. Final Report (v.1.1). Research technical report prepared for USDI, National Park Service. USGS/NPS Vegetation Mapping Program. 92 pp. plus appendices.
- Young, J., G. Fleming, P. Townsend, and J. Foster. 2007a. Vegetation of Shenandoah National Park in relation to environmental gradients. Final Report, volume 1.1. Unpublished report submitted to the U.S. Department of the Interior, National Park Service. 103 pp. plus appendices and GIS products.
- Young, J., G. Fleming, W. Cass, and C. Lea. 2009. Vegetation of Shenandoah National Park in relation to environmental gradients, Version 2.0. Technical Report NPS/NER/NRTR--2009/142. National Park Service, Philadelphia, PA. 389 pp.