Natural Heritage Inventory
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MARIAN PINKER TON BU LLMOOSE SH ARON DONEGAL SPRINGS MEETING HOUSE RUN OAK Conoy Creek Accomac, Marietta, Wrightsville Rivershore 772 Maytown Conoy Township East Donegal Township 441 D one Chiques Creek gal C r e Marietta e k West Hempfield Susquehanna River Township Chanceford Township (Limit of Aerial imagery) Columbia 30 Boro Lancaster County Natural Heritage Inventory Update 2008 Legend 462 Species of concern core habitat Natural Heritage Area Roads Wrightsville Lancaster County Supporting Landscape PA Turnpike Boro Streams All other roads Riparian Buffer Municipal Boundary (LimitAerialof imagery) York County 0 0.25 0.5 1 1.5 2 Miles Accomac, Marietta, Wrightsville Rivershore Accomac, Marietta, Wrightsville Rivershore – High significance PNHP Rank1 State Last Observed Species of Concern: Quality2 Global State Status1 (y-m-d) Plants: Scarlet ammannia (Ammannia coccinea) G5 S2 PE 2006-10-03 C Waterpod (Ellisia nyctelea) G5 S2 PT 1991-05-14 C Carolina leaf-flower (Phyllanthus caroliniensis) G5 S1 PE 2006-10-03 BC Tooth-cup (Rotala ramosior) G5 S3 PR 2006-10-03 C River bulrush (Schoenoplectus fluviatilis) G5 S3 PR 2006-10-03 C Sida (Sida hermaphrodita) G3 S2 PE 2006-10-03 CD Susquehanna trillium (Trillium sp.) GU SU TU 1996-05-01 C Animals: Bronze copper butterfly (Lycaena hyllus) G5 SU - 1996-08-31 E Sensitive species of concern3 - - - 1994 E 1 Please refer to Appendix IV for an explanation of PNHP ranks and legal status 2 Please refer to Appendix V for an explanation of quality ranks 3 This species is not named at the request of the agency overseeing its protection Location: This section of the Susquehanna River is roughly seven miles long, running from the railroad bridge just north of the Conoy / East Donegal Township line to the Columbia / Wrightsville Bridge, and includes riverside portions of the Borough of Marietta. o Municipalities: o Conoy Township, (Lancaster County) o East Donegal Township, (Lancaster County) o Marietta Borough, (Lancaster County) o West Hempfield Township, (Lancaster County) o Hellam Township, (York County) o Wrightsville Borough, (York County) o USGS Quadrangles: o Columbia West Quadrangle o York Haven Quadrangle o 1990 Lancaster Natural Areas Inventory reference: o “Vinegar Ferry” – (Columbia West Quadrangle) Description: The low, flood prone shoreline primarily on the Lancaster side of the Susquehanna River provides the appropriate habitat for most of the species of concern documented at this location. Flooding and river ice scour the shoreline, removing and replacing soil seasonally, which helps to create conditions favorable to annual plants that can go from seed to maturity in one growing season. The seasonally flooded areas and shallow mudflats between the railroad tracks and the river are of particular interest for plant species that thrive in the habitat created by this natural disturbance. Mudflats and shallow water habitats occur among the bedrock outcrops on either side of the Route 30 Bridge west of Columbia Borough; directly in front of the Borough of Marietta; on the west shore of the river and adjacent to Riverfront Park at Vinegar Ferry Road. The shallow mudflats exposed during periods of low river level provide habitat for wading birds who feed on 125 Accomac, Marietta, Wrightsville Rivershore aquatic plants and animals. This habitat also provides an important migratory stopping place for these and other birds that use the Susquehanna River as a migratory pathway. Species of Concern Considerations: Plants: o Four plant species of concern documented at this location are annual plants: the globally secure (G5), state imperiled (S2) scarlet ammania; the globally secure (G5), state imperiled (S2) waterpod; the globally secure (G5), state critically imperiled (S1) Carolina leaf-flower; and the globally secure (G5), state rare (S3) tooth-cup. They reach maturity from seed in a single season. They are adapted to the seasonal flooding disturbance and shallow water conditions inherent along the floodplain of the Susquehanna River and do well in habitats favoring ‘weedy’ species of plants. Populations of these species can be enhanced by maintaining the natural seasonal fluctuations in the water level of the river and the natural conditions of its shoreline. o River bulrush is a globally secure (G5), state rare (S3) perennial plant that is also adapted to the natural disturbance of seasonal flooding along the river. It is an emergent aquatic plant that can form dense stands from spreading roots. Populations of this plant can be enhanced by maintaining the natural seasonal fluctuations in the water level of the river and the natural conditions of its shoreline. o Sida is considered globally rare (G3) and state imperiled (S2) due to the few localized populations that occur around the world. Sida is a tall, robust, perennial plant that is also adapted to the natural disturbance of seasonal flooding along the river. Populations of this plant can be enhanced by maintaining the natural seasonal fluctuations in the water level of the river and the natural conditions of its shoreline. o Susquehanna trillium occurs in a forest ravine on the York County side of the Susquehanna River. The populations of declined trillium in the lower Susquehanna ravines are plants of uncertain taxonomy, which is to say, the populations of this trillium do not fall neatly into one species characterization. These populations may be hybrids between declined trillium and purple trillium (Trillium flexipes and Trillium erectum) and may be unique to the lower Susquehanna River. With the taxonomic uncertainty in mind, the Susquehanna trillium has not been given global and state status ranks. This taxonomic puzzle needs to be investigated further, but either way, the populations of these trilliums are worthy of conservation action. Conservation of the rich forested habitat should provide the protection needed for this species. Unauthorized collection for wildflower gardens is also a potential threat. Animals: o The principal habitat of the globally secure (G5), state undetermined (SU) bronze copper butterfly is found in wet meadows and marshes especially along river floodplains. The primary food source of the caterpillars of this species are plants in the buckwheat family (Polygonaceae) such as peach-leaved dock (Rumex altissimus). Conservation and expansion of this type of habitat in the area will help ensure continued breeding success for this species. Mowing of the area should be nonexistent, or selective and infrequent to help promote growth of host plants supporting this butterfly species of concern. o The core habitat for this sensitive species of concern is primarily in the adjacent Brunner (Lows) Island Natural Heritage Area to the north. This sensitive species of concern requires abundant food source and breeding areas. This can be achieved by preserving and improving the water quality of the Susquehanna River and by protecting and expanding the natural vegetation buffer along the river. Forest Cover / Natural Communities: The plant community types depicted are only approximations delineated from 2005 aerial photography interpretation and were followed up with minimal selective ground-truthing. Community types follow “Terrestrial & Palustrine Plant Communities of Pennsylvania” (Fike 1999) where appropriate, and describe general land cover types where they are not. o Most of the York County side of the river and adjacent hills is in nearly continuous forest cover dominated by a dry oak - heath forest and includes significant patches of interior forest. The narrow western shoreline floodplain has been largely converted to residential uses. o The Lancaster County side of the river is dominated by agriculture, urban and suburban land uses with only a few small parcels of forest cover remaining. The floodplain between the railroad tracks and the 126 Accomac, Marietta, Wrightsville Rivershore river adjacent to Riverfront Park is seasonally flooded and contains remnants of a silver maple floodplain forest and wet meadows interspersed with active agricultural fields and parkland. Ownership: o Much of the species of concern core habitat occurs in floodplain habitat that is subject to such intense flooding as to be considered part of the river. Floodplain areas between the river and the railroad tracks in this section are mostly owned by the respective municipalities. o A portion of the widest section of floodplain contains a small public park (Riverfront Park). o An industrial complex occupies a large parcel north of the Borough of Marietta. o The remaining river floodplain is held in several agricultural parcels and numerous urban residential parcels. Habitat Disturbances: o Historic – o The original forest cover of the area had been removed and converted to agricultural uses over the past several centuries, leaving little of the original vegetation in place. The borough of Marietta was constructed on the banks of the river including a portion of the floodplain. o Railroad tracks were built along the shoreline of the river, effectively severing the river from much of the original floodplain and the adjacent uplands. o Aerial photographs from 1940 indicate that a railroad siding/transfer hub appears to have been constructed north of Marietta, which is currently a large industrial complex. o Current – o Most of the eastern shore of this section of the river fails to function as a terrestrial habitat corridor through the region. A much wider and enhanced vegetated buffer is needed on the floodplain on the eastern shore of the Susquehanna River. The vegetated area between the railroad tracks and the river is in many areas too narrow to adequately function as a terrestrial habitat corridor. Animals traveling northward though the extensive forested river hills area are suddenly forced into a very narrow strip of land between the river and the railroad tracks to avoid the heavily urban, suburban and agricultural land uses north of Washington Borough, Columbia and Marietta. o The borough of Marietta has not grown significantly since 1940, although suburban growth has effectively filled the open space between Marietta and Maytown.