* limited to sites with higher soil calcium
Vascular plant nomenclature follows Rhoads and Block (2007). Bryophyte nomenclature follows Crum and Anderson (1981).

International Vegetation Classification Associations:

USNVC Crosswalk:

None

Representative Community Types:

Broadleaf Pond-lily Tidal Marsh (CEGL004472)
Atlantic Coast Wild Rice Tidal Marsh (CEGL004202)
North Atlantic Coastal Plain River Brackish Intertidal Mudflat (CEGL004473)
Atlantic Coast Brackish Tidal Marsh (CEGL004188)

NatureServe Ecological Systems:

Atlantic Coastal Plain Embayed Region Tidal Freshwater Marsh (CES203.259)

NatureServe Group Level:

None

Origin of Concept

Rhoads and Block

Pennsylvania Community Code*

na : Not Available

*(DCNR 1999, Stone 2006)

Similar Ecological Communities

There is overlap in species composition between Riverbank Freshwater Tidal Marsh and Freshwater Tidal Mixed High Marsh. One grades into the other at the level of mean high tide.

Fike Crosswalk

None. This type is new to the Pennsylvania Plant Community Classification developed from inventory studies of Bucks County by Morris Arboretum.

Conservation Value

Riverbank Freshwater Tidal Marsh is a rare community type in Pennsylvania that may have rare plant species including salt-marsh water-hemp (Amaranthus cannabinus), swamp beggar’s-ticks (Bidens bidentoides), small beggar-ticks (Bidens discoidea), showy bur-marigold (Bidens laevis), Walter’s barnyard grass (Echinochloa walteri), American waterwort (Elatine americana), spike-rush (Eleocharis obtusa var. peasii), dwarf spike-rush (Eleocharis parvula), mud-plantain (Heteranthera multiflora), gypsy-wort (Lycopus rubellus), goldenclub (Orontium aquaticum), long-lobed arrowhead (Sagittaria calycina), subulate arrowhead (Sagittaria subulata), river bulrush (Schoenoplectus fluviatilis), Smith’s bulrush (Schoenoplectus smithii), and wild-rice (Zizania aquatica). This community also provides a flood buffer along the Delaware Estuary as well as habitat for fish, birds, and aquatic invertebrates.

Threats

Threats to intertidal marsh communities include sea level rise; conversion to residential, commercial, or industrial uses; water pollution and colonization by non-native invasive species, especially common reed (Phragmites australis ssp. australis), Chinese lobelia (Lobelia chinensis), and umbrella sedge (Cyperus serotinus).

Loss of fine sediments due to erosion from the wakes of commercial ships and pleasure craft is also a major threat to riverbank tidal marsh communities. In several locations the surface layer of fine sediments and its stabilizing algal crust, which together provide a seed bed for intertidal plants, have been washed away leaving the riverbank bare of plants. Many of the intertidal species are annuals (Bidens bidentoides, Sagittaria calycina, Zizania aquatica, Amaranthus cannabinus, Echinochloa walteri) thus their persistence depends on an appropriate seedbed.

Management

There is a need to identify sites where existing land use could allow for inland migration of freshwater tidal marsh communities as sea level rises, and secure theses sites as protected open space. All remaining freshwater tidal marsh communities should be protected from incompatible land use. Opportunities for restoration of freshwater tidal marsh communities should also be pursued.

A natural buffer around the wetland should be maintained in order to minimize nutrient runoff, pollution, and sedimentation. The potential for soil erosion based on soil texture, condition of the adjacent vegetation (mature forests vs. clearcuts), and the topography of the surrounding area (i.e., degree of slope) should be considered when establishing buffers. The buffer size should be increased if soils are erodible, adjacent vegetation has been logged, and the topography is steep as such factors could contribute to increased sedimentation and nutrient pollution. Direct impacts and habitat alteration should be avoided (e.g., roads, trails, filling of wetlands) and low impact alternatives (e.g., elevated footpaths, boardwalks, bridges) should be utilized in situations where accessing the wetland cannot be avoided. Invasive species control should be implemented at sites where common reed (Phragmites australis ssp. australis) is established.

Range Map

Pennsylvania Range

Coastal Plain

Global Distribution

Connecticut, Delaware, Maine, Maryland, Massachusetts, North Carolina, New Hampshire, New Jersey, New York, Pennsylvania, and Virginia

Ferren, Wayne R. and Alfred E. Schuyler. 1980. Intertidal vascular plants of river systems near Philadelphia. Proceedings of the Academy of Natural Sciences of Philadelphia 132: 86-120.

Fike, J. 1999. Terrestrial and palustrine plant communities of Pennsylvania. Pennsylvania Natural Diversity Inventory. Harrisburg, PA.

NatureServe 2010. NatureServe Explorer: An online encyclopedia of life Version 7.1. NatureServe, Arlington, VA. Available http://www.natureserv.org/explorer (accessed: February 7, 2010).

Pennsylvania Department of Conservation and Natural Resources (DCNR). 1999. Inventory Manual of Procedure. For the Fourth State Forest Management Plan. Pennsylvania Bureau of Forestry, Division of Forest Advisory Service.  Harrisburg, PA. 51 ppg.

Schuyler, Alfred E. 1988. Submergent and planmergent flora of the freshwater portion of the Delaware Estuary. Chapter 10 in Ecology and Restoration of the Delaware River Basin, edited by S. K. Majumdar, E. W. Miller, and L. E. Sage. Pennsylvania Academy of Science.

Stone, B., D. Gustafson, and B. Jones. 2006 (revised). Manual of Procedure for State Game Land Cover Typing.  Commonwealth of Pennsylvania Game Commission, Bureau of Wildlife Habitat Management, Forest Inventory and Analysis Section, Forestry Division.  Harrisburg, PA. 79 ppg.

Titus, J. G., D. E. Hudgens, D. L. Trescott, M. Craghan, W. H. Nuckols, C. H. Hershner, J. M. Kassakian, C. J. Linn, P.G. Merritt, T. M. McCue, J. F. O’Connell, J. Tanski, and J. Wang. 2009. State and local governments plan for the development of most land vulnerable to rising sea level along the U.S Atlantic coast. Environmental Research Letters 4 (doi:10.1088/1748-9326/4/4/044008).