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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 />

COMMON NAME (PARK-SPECIFIC): COASTAL PLAIN CALCAREOUS SEEPAGE<br />

SWAMP<br />

SYNONYMS<br />

USNVC English Name: Red Maple - Green Ash / Golden Groundsel - Bromelike Sedge<br />

- Lesser Clearweed - Smooth Beggarticks Forest<br />

USNVC Scientific Name: Acer rubrum - Fraxinus pennsylvanica / Packera aurea - Carex<br />

bromoides - Pilea fontana - Bidens laevis Forest<br />

USNVC Identifier: CEGL006413<br />

LOCAL INFORMATION<br />

Environmental Description: Coastal Plain Calcareous Seepage Swamp includes deciduous<br />

forests occurring on moderately to highly base-rich substrates in the bottoms of ravines that have<br />

downcut into Tertiary shell deposits or limes<strong>and</strong>s. Habitats consist of mucky, braided ravine<br />

bottoms saturated by constant groundwater seepage, <strong>and</strong> soils with high base status. Hummock<strong>and</strong>-hollow<br />

microtopography is prevalent, <strong>and</strong> exposed shells are common in springs <strong>and</strong> rills.<br />

<strong>Vegetation</strong> Description: Fraxinus pennsylvanica (green ash) <strong>and</strong> Acer rubrum (red maple) are<br />

common overstory trees in most st<strong>and</strong>s, but a subset of ravines on the south side of the James<br />

River features the unusual codominance of Taxodium distichum (bald cypress). Climbing lianas<br />

<strong>and</strong> seedlings of Decumaria barbara (woodvamp) are abundant. Small trees <strong>and</strong> shrubs include<br />

Fraxinus pennsylvanica (green ash), Ulmus americana (American elm), Liquidambar styraciflua<br />

(sweetgum), <strong>and</strong> Lindera benzoin (northern spicebush). Common or patch-dominant herbs on the<br />

better-drained hummocks include Packera aurea (golden ragwort), Scirpus lineatus (drooping<br />

bulrush), Carex bromoides (bromelike sedge), Thelypteris palustris var. pubescens (eastern<br />

marsh fern), Cicuta maculata var. maculata (spotted water hemlock), <strong>and</strong> Carex granularis<br />

(limestone meadow sedge). Mucky hollows <strong>and</strong> seepage rills support abundant Saururus cernuus<br />

(lizard's tail), Bidens laevis (smooth beggartick), Pilea fontana (lesser clearweed), Glyceria<br />

striata (fowl mannagrass), <strong>and</strong> Impatiens capensis (jewelweed).<br />

Disturbed st<strong>and</strong>s of this type may have Platanus occidentalis (American sycamore) in the<br />

canopy. Some st<strong>and</strong>s are codominated by Taxodium distichum (bald cypress).<br />

Most Abundant Species:<br />

Stratum Lifeform<br />

Species<br />

Tree canopy<br />

Broad-leaved deciduous tree Acer rubrum (red maple),<br />

Fraxinus pennsylvanica (green ash)<br />

Herb (field) Forb Packera aurea (golden ragwort),<br />

Saururus cernuus (lizard's tail)<br />

Herb (field)<br />

Graminoid Scirpus lineatus (drooping bulrush)<br />

Characteristic Species: Acer rubrum (red maple), Fraxinus pennsylvanica (green ash), Packera<br />

aurea (golden ragwort), Pilea fontana (lesser clearweed), Saururus cernuus (lizard's tail),<br />

Scirpus lineatus (drooping bulrush).<br />

Other Noteworthy Species:<br />

Species GRank Type Note<br />

Ponthieva racemosa (hairy shadow witch) - plant VA watchlist (S3)<br />

Scirpus lineatus (drooping bulrush)<br />

- plant VA watchlist (S3)<br />

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