Natural Community Systems -- Photo Guide

Sand plain basin marsh system

a sand plain basin marsh system in southern New Hampshire (photo by Ben Kimball for the NH Natural Heritage Bureau)
a sand plain basin marsh system in southern New Hampshire (photo by Ben Kimball)


DescriptionThese marshes occur in closed basins (having no inlets or outlets) in sand plain settings (outwash and other ice-contact deposits).  In contrast to peatlands in closed basins, these wetlands have widely fluctuating seasonal and annual water levels, and no or relatively little organic matter accumulation in at least a portion of the basin.  As with sandy pond shore systems, these wetlands have infertile mineral soils and support a combination of common wetland marsh plants and uncommon stress-tolerators and ruderals (including numerous coastal plain species) that are rare or infrequent in other habitats in the state.  They occur primarily in central and southern New Hampshire although a few examples that lack coastal plain species can be found in the White Mountain region.  Concentric vegetation zonation is typical and wave and ice action is absent.  Many of the same species listed for sandy pond shore system occur in sand plain basin marsh systems, plus others.  Examples with the meadow beauty sand plain marsh community contain numerous rare and coastal plain species that have a preference for a well-developed sandy drawdown zone.


Diagnostic natural communities:

      • Highbush blueberry - winterberry shrub thicket (S4)

      • Buttonbush shrubland (S4)

      • Meadowsweet - robust graminoid sand plain marsh (S3S4)

      • Meadow beauty sand plain marsh (S1)

      • Three-way sedge - mannagrass mudflat marsh (S2S3)

      • Spike-rush - floating-leaved aquatic mudflat marsh (S1)

      • Sharp-flowered mannagrass shallow peat marsh (S1)

      • Montane sandy basin marsh (S1)

Peripheral or occasional natural communities:

      • Red maple - Sphagnum basin swamp (S4)

      • Swamp white oak basin swamp (S1)

      • Pitch pine - heath swamp (S1S2)


Landscape settings: shallow depressions in outwash, ice-contact deposits and other glacio-fluvial soils; semi-perched or groundwater-connected

Soils: sand or gravelly sand with shallow muck or sandy muck surface horizons; poorly to very poorly drained; seasonally and semi-permanently flooded to intermittently exposed; oligotrophic; topogenous and groundwater influence (vertical fluctuations dominant)

Spatial pattern:
small patch (<1 - 15 acres); individual basins with oval, circular and irregular shapes; occur as single basins or as clumps of separate basins in close proximity with no or only intermittent surface water connection; concentric zonation

Physiognomy:
tall-medium shrub, tall herbaceous, short herbaceous, floating and submersed aquatic

Distribution:
mostly east-central and southern New Hampshire, occasional further north


Characteristic species:
   
Rhexia virginica (Virginia meadow beauty)
   Cladium mariscoides (twig-rush)
   Viola lanceolata (lance-leaved violet)
   Euthamia tenuifolia (fine grass-leaved goldenrod)
   Cyperus dentatus (bulblet umbrella-sedge)
   Juncus pelocarpus (mud rush)
   Gratiola aurea (golden-pert)
   
Agalinis purpurea var. parviflora (small-flowered gerardia)
   Eriocaulon aquaticum (pipewort)
   Sagittaria latifolia (common arrowhead)
   Eleocharis tenuis (slender spike-rush)
   Panicum spretum (spurned panic-grass)
   Xyris difformis (robust yellow-eyed grass)


Associated natural community systems:  These systems are typically set in upland forest mosaics and thus isolated from other wetlands.  Occasionally they are adjacent to temperate or coastal conifer peat swamp systems with shallow organic horizons (see peripheral or occasional natural communities above).


sand plain basin marsh communities
An idealized sequence of natural communities in a sand plain basin marsh system.
Other natural community combinations are possible.


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