Classification of Vegetation Communities of Maryland: First Iteration

III. SHRUBLAND
III.B.2.N.h. Tidal cold-deciduous shrubland
A.1024—ALNUS (INCANA, SERRULATA, MARITIMA)
TIDAL SHRUBLAND ALLIANCE (III.B.2.N.h.2)
(Speckled Alder, Smooth Alder, Seaside Alder) Tidal Shrubland Alliance

Summary: Tidal freshwater, or perhaps also oligohaline, shrublands dominated by Alnus serrulata and/or Alnus incana. Alnus maritima dominates some tidal shrublands on the Delmarva peninsula. In some examples one or both of these may be characteristically dominant or nearly so. Other examples may be more semi-open with a mixed canopy of Alnus with other shrubs such as Cornus amomum, Rosa palustris, and Ilex verticillata. Other woody plants which may be present include Sambucus canadensis, Salix spp., Amorpha fruticosa, Cephalanthus occidentalis, and Toxicodendron radicans. More northern examples may contain Viburnum recognitum and Spiraea alba var. latifolia (= Spiraea latifolia). This alliance occurs along tidal freshwater reaches of rivers. One association is recognized along the south Atlantic Coast to South Carolina and possibly elsewhere. This can occur as a fringing shrubland, zonal between Zizania aquatica tidal marshes and tidal cypress - gum forests. Less commonly it occupies large patches in freshwater marshes. Other species characteristic of tidal situations often occur, including Rosa palustris and Zizania aquatica. Another association is recognized in coastal areas with tidally influenced river systems from Maine to Virginia. Flood waters are typically slightly acid (pH less than 5) and soils are usually mineral without significant peat deposits. In these examples, Carex stricta may also be present and there is a great deal of micro-relief (tussocks and furrows) leading to high species diversity. Some shrub associates include Decodon verticillatus and Toxicodendron vernix; some herbaceous associates are Osmunda regalis, Thelypteris palustris, Galium spp., Typha latifolia, Peltandra virginica, Mikania scandens, Symphyotrichum novi-belgii (= Aster novi-belgii), Boehmeria cylindrica, Impatiens capensis, Triadenum walteri, Asclepias incarnata, Carex emoryi, Carex atlantica ssp. atlantica (= Carex incomperta), Eriophorum virginicum, Platanthera clavellata, and Xyris torta.

Range: This alliance is found in Georgia, South Carolina, Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Virginia, and possibly Florida (?), North Carolina (?), and others.

States/Provinces: CT DE FL? GA MA MD ME NC? NJ NY PA SC VA?

TNC Ecoregions: 43:P, 56:C, 57:C, 58:C, 61:C, 62:C

USFS Ecoregions: 221Aa:CCP, 221Ab:CCP, 221Ac:CCC, 221Ad:CCC, 221Ae:CCC, 221Ag:CCC, 221Ak:CCC, 221Ba:CCC, 221Bc:CCC, 222:C, 232Aa:CCP, 232Ab:CCC, 232Ac:CCC, 232Ad:CCC, 232Br:CCC, 232Bt:CCC, 232Bx:CCC, 232Bz:CCC, 232Cb:CCC, 232Ce:CCC, 232Ch:CC?, 232Ci:CC?

Synonymy: Estuarine Intertidal: Fresh/Brackish Tidal Shrubland (Swain and Kearsley 2001)

References: Sneddon et al. 1996, Swain and Kearsley 2001

Authors: A.S. WEAKLEY, MOD. L.A. S

Summary: This tidal shrubland of the Delmarva peninsula on the central Atlantic coast occurs on freshwater tidal rivers and tributaries. Waters are generally oligohaline, but may receive pulses of higher salinities during spring high tides or low river discharge. The vegetation occurs on the ecotones between freshwater tidal marshes and tidal swamps. Hummocks and hollows are characteristic, and the substrate is poorly drained slightly acidic tidal muck with silts, fine sands and partially decomposed peat admixed. The shrub canopy is well developed, often dense, and dominated by Alnus maritima. Associated shrub species are few and at low cover, but may include Viburnum dentatum, Cornus amomum or Sambucus canadensis. Vines may include Toxicodendron radicans and Mikania scandens. The herbaceous layer is dominated by Acorus calamus, with other associates including Impatiens capensis, Peltandra virginica, Polygonum sagittatum, Leersia oryzoides, Cinna arundinacea, Polygonum arifolium, Boehmeria cylindrica, Thalictrum pubescens (= Thalictrum polygamum), and Sambucus canadensis.

Range: This vegetation occurs on the Delmarva peninsula of the central Atlantic coast.

State/Provinces: MD:S3.1, DE:SP

TNC Ecoregions: 58:C

USFS Ecoregions: 232Bt:CCC, 232Bx:CCC, 232Bz:CCC

References: Harrison 2003

Authors: J. Harrison / L. Sneddon Confidence: 3 Identifier: CEGL006841

- Maryland Vegetation Classification Subset Report III. Shrubland

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