![]() ![]() Although most major oligohaline systems are represented, additional data are needed to refine the classification of several community types. Six community types have been classified based on analysis of data from 75 plots (Fig. References: Coulling (2002), Megonigal and Darke (2001), Perry and Atkinson (1997), The Nature Conservancy (1997).Ĭlick here for more photos of this ecological community group. (see the Wind-Tidal Oligohaline Marshes ECG.) The diurnally tidal communities in this group are compositionally distinct from the group of more diverse oligohaline marshes in extreme southeastern Virginia that are subject to irregular wind tides. australis ) this highly aggressive, invasive subspecies constitutes a serious threat to tidal marshes throughout the Coastal Plain. Diversity generally decreases as halinity increases, but some communities of mixed composition, particularly those of low stature, may support more species than many tidal freshwater marshes.ĭredge spoils and other disturbed areas often support dense, nearly monospecific colonies of common reed ( Phragmites australis ssp. Some oligohaline marshes contain dense colonies of shoreline sedge ( Carex hyalinolepis) or, more commonly, narrow-leaf cattail ( Typha angustifolia), the latter of which may be increasing in extent as the result of fire exclusion and eutrophication. Other species indicative of oligohaline conditions (when occurring in marshes) include halberd-leaved tearthumb ( Persicaria arifolia), swamp barnyard grass ( Echinochloa walteri), and swamp dock ( Rumex verticillatus). Associates include a mix of species characteristic of freshwater marshes, such as dotted smartweed ( Persicaria punctata ) and arrow-arum ( Peltandra virginica), and species more tolerant of higher salinities, such as swamp rose-mallow ( Hibiscus moscheutos) and seashore mallow ( Kosteletzkya pentacarpos). In Virginia, big cordgrass ( Spartina cynosuroides) is the most characteristic and abundant species and often forms extensive, tall stands, particularly along edges of the main tidal channels. Vegetation in this group occurs from Maine to Georgia. Oligohaline conditions are defined as salt concentrations between 0.5 and 5 ppt, although pulses of higher halinity may occasionally occur. This group contains primarily graminoid-dominated wetlands of slightly brackish zones along tidal rivers and streams of the Coastal Plain. Your browser does not support JavaScript! Summary of Procedures for Collection & Analysis of Vegetation Data.Tidal Mesohaline and Polyhaline Aquatic Beds.Tidal Freshwater and Oligohaline Aquatic Beds.Tidal Mesohaline and Polyhaline Marshes.Saturated Peatlands of the Coastal Plain.Coastal Plain / Piedmont Seepage Swamps.Coastal Plain Depression Swamps and Ponds.Non-Alluvial Wetlands of the Coastal Plain & Piedmont.Piedmont / Mountain Small-Stream Alluvial Forests.Piedmont / Mountain Floodplain Forests and Swamps.Coastal Plain / Piedmont Bottomland Forests.Sandy Woodlands of the Coastal Plain and Outer Piedmont.Lichen / Bryophyte Nonvascular Cliffs and Boulderfields.Piedmont Oak - Hickory Woodlands, Savannas, and Grasslands.Limestone / Dolostone Woodlands and Barrens.Low-Elevation Woodlands, Barrens, and Rock Outcrops.Coastal Plain / Piedmont Oak - Beech / Heath Forests.Montane Mixed Oak and Oak - Hickory Forests.Montane Dry and Dry-Mesic Calcareous Forests.Low-Elevation Dry and Dry-Mesic Forests.High-Elevation Boulderfield Forests and Woodlands. ![]() Southern Appalachian Shrub and Grass Balds.High-Elevation Forests, Grasslands, and Rock Outcrops.Overview of VA Physiography & Vegetation.Structure of the Virginia Natural Community Classification.Home » Natural Heritage » Natural Communities » Tidal oligohaline Marshes The Natural Communities of VirginiaĬlassification of Ecological Groups and Community Types Third Approximation (Version 3.3) Information current as of March 2021Ĭlassification of Ecological Groups and Community Types ![]()
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