Name:
NY Heritage: Coastal plain pond shore
Reference:
Ecological Communities of New York, 2nd Ed.
Description:
The gently sloping shore of a coastal plain pond with seasonally and annually fluctuating water levels. The substrate is sandy, gravelly, or mucky. Vegetative cover at any point varies seasonally and annually with the water levels. In dry years when water levels are low and the substrate is exposed, there is a dense growth of annual sedges, grasses, and herbs. Submerged and floating-leaved aquatic plants, such as fragrant waterlily (Nymphaea odorata) and pondweeds (Potamogeton spp.), may become "stranded" on the exposed shore. In wet years when the water level is high and the substrate is flooded, vegetation is sparse, and only a few emergents and floating-leaved aquatics are apparent. A description of the aquatic component is included under the coastal plain pond community. The vegetation of this pond shore community can change dramatically from one year to the next depending on fluctuations in groundwater levels.
Coastal plain pond shores on Long Island can be divided into four distinct zones following the proposed classification by Zaremba and Lamont (1993):
1. The upper wetland shrub thicket zone is treated as either pine barrens shrub swamp or the coastal variant of highbush blueberry bog thicket. This zone may also grade into red maple-black gum swamp, coastal plain Atlantic white cedar swamp, or, in pond shores with steeper slopes, pitch pine-oak forest.
2. The upper, low herbaceous fringe zone is a narrow band of vegetation with peaty substrate mixed with sand. The dominant plants of this zone are peat moss (Sphagnum spp.), yellow-eyed grass (Xyris difformis), narrow-leaved goldenrod (Euthamia tenuifolia), bluejoint grass (Calamagrostis canadensis), clubmosses (Lycopodiella inundata, L. appressa). Other plants of this zone include (Agalinis virgata), sedge (Carex striata), sundews (Drosera intermedia, D. filiformis), creeping St. John's-wort (Hypericum adpressum), slender blue-flag (Iris prismatica), redroot (Lacnanthes caroliniana), Nuttall's lobelia (Lobelia nuttallii), water-horehound (Lycopus amplectans), panic grasses (Panicum acuminatum, P. verrucosum, P. wrightianum), and large cranberry (Vaccinium macrocarpon). Occasionally, scattered seedlings of Atlantic white cedar (Chamaecyparis thyoides) may be found in this zone.
3. The sandy exposed pond bottom zone is often very sandy and dominated by annual species. This zone may be extremely wide at ponds with very gradual pond bottom slopes. The dominant plants of this zone are beakrushes (Rhynchospora capitellata, R. nitens), and nutrush (Scleria reticularis var. reticularis). Other species of this zone include yellow-eyed grass (Xyris difformis), Canadian St. John's-wort (Hypericum canadense), rushes (Juncus pelocarpus, J canadensis), rose coreopsis (Coreopsis rosea), spikerushes (Eleocharis melanocarpa, E. tuberculosa), umbrella-grass (Fuirena pumila), ludwigia (Ludwigia sphaerocarpa), bald-rush (Rhynchospora scirpoides), white beakrush (Rhynchospora alba), Virginia meadow-beauty (Rhexia virginica), marsh St. John's-wort (Triadenum virginicum), bladderwort (Utricularia subulata).
4. The organic exposed pond bottom zone is more frequently flooded than the sandy zone, hence has a greater accumulation of organics. The dominant plants of this zone can be extremely variable from year to year depending on the degree of flooding. In high water years, annual species that cannot germinate underwater are usually absent and submerged and floating-leaved aquatic plants are more abundant. In contrast, annual species tend to flourish in low water years and the aquatic species become less prevalent. The dominant plants of this zone are bald-rush (Rhynchospora scirpoidesl), pipewort (Eriocaulon aquaticumh), (Eleocharis obtusal, E. olivaceal), gratiola (Gratiola aurea). Other species of this zone include twigrush (Cladium mariscoides), (Eleocharis robbinsii), bayonet rush (Juncus militaris), mermaid-weed (Proserpinaca pectinata), beaked rushes (Rhynchospora macrostachya, R. inundata,), quill-leaf arrowhead (Sagittaria teres h), bladderworts (Utricularia junceal, U. fibrosa, U. purpureah, U. striata), yellow-eyed grasses (Xyris smalliana, X. torta).
h = more abundant in high water years
l = more abundant in low water years
Characteristic animals include eastern painted turtle (Chrysemys picta picta), muskrat (Ondatra zibethica), various dragonflies and damselflies, and chain pickerel (Esox niger). Rare animals of some coastal plain ponds and pond shores include bluets (Enallagma recurvatum, E. laterale, E. pictum), eastern mudminnow (Umbra pygmaea), tiger salamander (Ambystoma tigrinum), and banded sunfish (Enneacanthus obesus).
The primary disturbance in coastal plain pond shores is a periodic cycle of flooding and draw down. Hydrology of the ponds is controlled by a long term 2-3 year cycle of draw down and flooding tightly linked with local rainfall amounts and, in some ponds, local groundwater levels (Schneider 1992). The amount of groundwater influx for a given pond or pond system appears to be influenced by landscape position. For example, pond shores in proximity to topographical highs, such as kames and morainal hills, appear to have increased amounts of groundwater flow versus ponds in more level topography (Schneider 1992). Ponds positioned at higher elevations draw down faster than neighboring ponds at lower elevations. Secondary disturbances include fire, which influences vegetation at the pond shore shrub margin and may effect the amount of organic material in the pond substrate (Zaremba and Lamont 1993).
Because of the characteristic zones of vegetation that dominate a pond shore in any given year, ponds may have a number of different vegetation assemblages based on the extent of draw down, position within the pond shore, and overall composition of vegetation within a specific pond (Graham and Henry 1933, Zaremba and Lamont 1993, Schneider 1994). Coastal plain pond shores are a dynamic collection of vegetation and a well-zoned pond shore may display one or more vegetation associations in a single growing season. The vegetation associations that dominate New York pond shores probably should be recognized as stochastic, repeating vegetation "zones" that appear as a function of periodic fluctuation of hydrology (Zaremba and Lamont 1993, Schneider 1994).
The invasion of reedgrass (Phragmites australis) is a serious threat to this community.
Accession Code:
VB.CC.28635.NYHERITAGECOAST
Plot-observations of this Community Concept:
1
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