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Vegetation Classification and Mapping Project Report - USGS

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<strong>USGS</strong>-NPS <strong>Vegetation</strong> <strong>Mapping</strong> Program<br />

Colonial National Historical Park<br />

<strong>Classification</strong> Comments: Tidal Bald Cypress Forest / Woodl<strong>and</strong> is distinguished from most<br />

mapping units in Colonial National Historical Park by being dominated by Taxodium distichum<br />

(bald cypress). However, examples of Coastal Plain Calcareous Seepage Swamp at Swanns Point<br />

are also dominated by Taxodium distichum (bald cypress) <strong>and</strong> can have high coverage of Carex<br />

hyalinolepis (shoreline sedge) in areas ecotonal to tidal swamp. St<strong>and</strong>s of Coastal Plain<br />

Calcareous Seepage Swamp with Taxodium distichum (bald cypress) are distinguished from<br />

Tidal Bald Cypress Forest / Woodl<strong>and</strong> by their non-tidal hydrology <strong>and</strong> having more species<br />

diversity in all strata, with high cover of species such as Asimina triloba (pawpaw), Ilex opaca<br />

var. opaca (American holly), Carex bromoides (bromelike sedge), Lindera benzoin (northern<br />

spicebush), <strong>and</strong> Saururus cernuus (lizard's tail).<br />

Other Comments: Small areas within the map class Disturbed Tidal Hardwood Swamp may<br />

represent disturbed examples of Tidal Bald Cypress Forest / Woodl<strong>and</strong>. Tidal Bald Cypress<br />

Forest / Woodl<strong>and</strong> is a globally rare community with a restricted range. The example of this<br />

association at Swanns Point meets the criteria to be considered a Natural Heritage exemplary<br />

natural community occurrence.<br />

Local Description Authors: K. D. Patterson.<br />

Plots: COLO.26, COLO.27, COLO.103.<br />

Colonial National Historical Park Inventory Notes: Information not available.<br />

GLOBAL INFORMATION<br />

USNVC CLASSIFICATION<br />

Physiognomic Class Woodl<strong>and</strong> (II)<br />

Physiognomic Subclass Deciduous woodl<strong>and</strong> (II.B.)<br />

Physiognomic Group Cold-deciduous woodl<strong>and</strong> (II.B.2.)<br />

Physiognomic Subgroup Natural/Semi-natural cold-deciduous woodl<strong>and</strong> (II.B.2.N.)<br />

Formation Tidal cold-deciduous woodl<strong>and</strong> (II.B.2.N.f.)<br />

Alliance Taxodium distichum Tidal Woodl<strong>and</strong> Alliance (A.659)<br />

Alliance (English name) Bald-cypress Tidal Woodl<strong>and</strong> Alliance<br />

Association Taxodium distichum / Carex hyalinolepis Woodl<strong>and</strong><br />

Association (English name) Bald-cypress / Shoreline Sedge Woodl<strong>and</strong><br />

Ecological System(s): Northern Atlantic Coastal Plain Tidal Swamp (CES203.282).<br />

Southern Atlantic Coastal Plain Tidal Wooded Swamp (CES203.240).<br />

GLOBAL DESCRIPTION<br />

Concept Summary: This community occurs in narrow b<strong>and</strong>s along the fringes of wind-tidal<br />

marshes on the Northwest River <strong>and</strong> North L<strong>and</strong>ing River in southeastern Virginia, <strong>and</strong> likely<br />

occurs in northeastern North Carolina as well. It also occurs on the Pocomoke River of<br />

Maryl<strong>and</strong>, where it is influenced by lunar, rather than wind tides. Substrates are poorly<br />

decomposed to moderately decomposed, root-rich peats. These sites are frequently flooded by<br />

wind tides or lunar tides <strong>and</strong> have some st<strong>and</strong>ing water throughout the growing season. This<br />

community usually develops in narrow ecotones between water-fringing marshes <strong>and</strong> tidal<br />

swamp forests, but may also occur between marshes <strong>and</strong> upl<strong>and</strong> forests. Taxodium distichum<br />

(bald cypress) dominates the open to sparse canopy. Other less common tree species may include<br />

Nyssa biflora (swamp tupelo), Liquidambar styraciflua (sweetgum), <strong>and</strong> Acer rubrum (red<br />

maple). Fraxinus profunda (pumpkin ash) <strong>and</strong> occasional Chamaecyparis thyoides (Atlantic<br />

white cedar) also occur in Maryl<strong>and</strong> examples. The sparse to moderately dense shrub layer is<br />

dominated by Morella cerifera (wax myrtle), Clethra alnifolia (coastal sweetpepperbush), Rosa<br />

palustris (swamp rose), <strong>and</strong> Toxicodendron radicans ssp. radicans (eastern poison ivy). The<br />

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