MARIAN IKRTON PINKER 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 ( 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

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aquatic plants and . 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 , 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 () 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

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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. Stormwater runoff from Marietta and the surrounding communities flows into the river system with little opportunity to be filtered, a potentially significant non-point source of pollution. Treated wastewater from Marietta is also returned to the river system. o The railroad hub north of Marietta has grown into a large industrial complex. Runoff from past and present activities at this complex could be a significant source of thermal and chemical pollution directly entering the Susquehanna River. A past survey of the river shoreline near Marietta indicated that aluminum shavings were washing from a nearby factory into the river. o A significant section of mature floodplain forest south of Vinegar Ferry Road has been cleared. This was an unfortunate elimination of a good example of this habitat type for this area. o Many cottages and residences have been built along the western shore of the river in York County, disturbing, altering and removing the natural river shore floodplain habitat. Several new access roads, utility rights-of-way and residences have been built on the hills overlooking the river, fragmenting this otherwise intact forest. Portions of the forest that had been in active agriculture in 1940 photographs have since returned to forest cover. o Wave action from motorboats can also have an impact on the shallow water habitats in the area. Increased wave action can dislodge small plants from mudflats. Boaters should also avoid harassing nesting and feeding birds. o Garden debris and other refuse dumped into the river floodplain can be a significant source of invasive plant species and general habitat degradation. o Exotic Species –

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o The natural disturbance of seasonal flooding and ice scour create ideal conditions for many introduced species of plants. Consequently, the river shoreline is prone to invasion from a large number of invasive species. Past site surveys were unlikely to document newly introduced highly aggressive species such as mile-a-minute (Polygonum perfoliatum) and Japanese stiltgrass (Microstegium vimineum) which are likely to occur in these habitats. Invasive species that were recorded during past surveys include: o Japanese honeysuckle (Lonicera japonica) o Garlic mustard (Alliaria petiolata) o Common privet (Ligustrum vulgare, Ligustrum obtusifolium) o Multiflora rose (Rosa multiflora) o Asiatic bittersweet (Celastrus orbiculatus) o Bush honeysuckles (Lonicera morrowii, Lonicera maackii) o Japanese knotweed (Polygonum cuspidatum) o Purple loosestrife (Lythrum salicaria) o Tree-of-heaven (Ailanthus altissima)

Conservation Actions:

Overall: o Coordinate the protection of this landscape between Lancaster and York Counties. o Protect and expand the natural vegetation along the eastern shore of the river floodplain and adjacent upland. Consider expansion of a wide strip of native vegetation as a terrestrial habitat corridor along the eastern shore of the river. o Avoid building, replacing or expanding dams on the Susquehanna River. o Riparian corridors of all stream tributaries to this section of the Susquehanna River and the river shoreline itself on the Lancaster County side need additional restoration measures. Many stretches of streams in this area lack vegetated riparian buffers and are nearly or fully unprotected from agricultural runoff. o High water quality and appropriate substrate are both critical aspects to sustaining suitable habitat in this section of the river. Establish at least 100 m (328 ft) buffer of woody vegetation along the river shore and all segments of tributary streams to help protect the water quality of the river by reducing erosion, sedimentation, and pollution. Best management practices (BMPs) that focus on limiting nutrient and soil loss into surface and groundwater should be applied to surrounding agricultural lands. This would help maintain and improve water quality in the river.

Within the Core Habitat: o Most of the species of concern core habitat occurs within the riverbed or its adjacent floodplain. Maintain the natural hydrology of the river system by avoiding building dams. Maintain and improve water quality of the river by providing vegetated buffers along inflows to the river. Detention basins and rain gardens can be incorporated into borough infrastructure to allow stormwater to be filtered before entering the river. o The floodplain adjacent to Riverfront Park should be considered a priority for restoration to wet meadow and floodplain forest natural communities, perhaps as an expansion of Riverfront Park. Emphasis should be on promoting a viable floodplain natural community rather than expansion of active park facilities and infrastructure. Mowing of the area should be minimized or eliminated with special emphasis on protecting and expanding wet meadow areas with native vegetation and restoration and protection of the natural condition of the shoreline. o The rainwater runoff from the agricultural fields and pastures should be considered a potential source of significant contamination for the river. Runoff from these sources have significantly higher levels of sediment, nutrients, pesticides, herbicides and other pollutants than runoff filtered through a natural habitat. Stormwater management measures such as the creation of detention

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basins or vegetated swales should be implemented to break up the uninterrupted expanses of cultivated ground in these large agricultural landscapes.

Within the Supporting Landscape: The supporting landscape was drawn around the subwatersheds leading to this stretch of the Susquehanna River. Activities and land use patterns in the subwatersheds can have a significant impact on the water quality of the river and the habitats of the species of concern. o All of the conservation actions for the core habitat also apply to the supporting landscape. o In addition, the intensively cultivated landscape offers little natural habitat for native species of plants and animals. Portions of the area, particularly the unnamed tributaries to the Susquehanna River culminating at Rowenna, Marietta and through the industrial complex should be restored to native trees and shrubs to provide an increased buffer for storm water and agricultural runoff filtration, and to provide habitat diversity for a wider range of native plants and animals. Expansion of native vegetation along the creeks and streams will also provide greater connectivity between and among the adjacent natural habitats, providing a corridor for and plant movement within this portion of the county. o Preserve and improve the integrity of the large unfragmented forest blocks on the western shore of the Susquehanna River. These large forested areas provide a significant filter for runoff entering the river from these slopes. The steep, rocky nature of the wooded slopes likely precludes most types of development activity. The flatter hilltops, however, could prove tempting building sites. Avoid activities that would fragment this habitat or create more edge areas, such as road building, which encourages the introduction of invasive plants or edge-adapted species. o The immediate watershed draining into the river includes some forested areas and agricultural fields. Logging of wooded areas, specifically along steep slopes and riparian borders would be detrimental to the watershed. Nutrients from agricultural fields, failures from septic systems within the watershed, lawn care fertilizers and other sources can accumulate in the river leading to algal blooms and the consequent death of aquatic organisms. The amount of impervious surfaces around the river can allow all types of chemical runoff from roads, building materials etc. to reach and contaminate the river. o The long term goal for the area should be to restore mature floodplain forests and the associated upland buffer forests along the eastern shore of the river. Expand the native vegetation along the river corridor to include land within 300 meters of the river’s banks. Reforestation efforts should be designed to mimic the adjacent natural community type by planting a similar composition of native trees and shrubs of varying age classes. Reforestation is a labor intensive effort that requires long term monitoring and maintenance to avoid infestation by invasive species of plants. o The habitat of the western shoreline floodplain would be improved by the removal of the residences lining the floodplain of the river. o Pursue conservation easements and fee simple acquisition on properties along the river shoreline, the adjacent slopes and forested plateaus to help conserve the effectiveness of the Susquehanna River natural corridor. o Educate homeowners about the effects of the overuse of fertilizers, pesticides, and herbicides on groundwater. Promote groundwater quality awareness when conducting education and outreach programs, and provide educational information about potential threats to water supply. o Potential zoning options for conservation enhancement: o Strict enforcement of regulations restricting building activity on slopes greater than 25% would help prevent the forested slopes from being converted to other uses. o Conoy, East Donegal and West Hempfield Townships all have a zoning ordinance in their Comprehensive Plans restricting new construction within the 100-year floodplain of all waterways. Strict enforcement of these regulations will help prevent conversion of the floodplain to many unsuitable uses and help protect most of the species of concern core habitat. o Floodplain regulations should be updated to prohibit agricultural activities within the 100-year floodplain as well. Chemical, nutrient and sediment runoff into waterways from agricultural sources can be significantly reduced by returning seasonally flooded areas to natural habitats. 129 Accomac, Marietta, Wrightsville Rivershore

o West Hempfield Township’s floodplain ordinance requires a minimum 15 foot filter strip planted in grass between any watercourse and any tilled land. The ordinance should be updated to allow native trees and shrubs to be planted in the filter strip. Mowing along filter strips should be discouraged. o Zoning regulations should discourage further fragmentation of contiguous or interior forest blocks. Parcels currently forested should be zoned to conserve this attribute. o Parcels currently in agriculture that are of high quality agricultural soils should be zoned agricultural and considered fully built-out. Poorer quality agricultural soils and those within the 100-year floodplain should be encouraged to regenerate into forest cover / natural wetland communities. o Growth within the Township should be discouraged to occur within 300 meters of the 100-year floodplain of the Susquehanna River or within 100 meters from the floodplain of its tributaries. o Growth should be encouraged to occur clustered in close proximity to existing infrastructure to avoid unnecessary habitat destruction. o Potential restoration activities: o Streams through forested areas should be considered high priority for conservation in the habitat. The forested riparian corridor helps to regulate the temperature of the stream and creates streamside conditions that contribute to improved water quality and aquatic habitat. Streams through non-forested areas should be restored with native trees and shrubs appropriate to the habitat. o Careful determination is needed to avoid planting trees in floodplains that contain herbaceous wetland habitats. These habitats should be maintained in their current open condition, with tree plantings to occur at the periphery of natural wetland openings. o Riparian Buffers: o An ideal vegetated stream buffer should be at least 100 meters (~300 feet) in width from the edge of the 100-year floodplain. o An intermediate vegetated stream buffer should be at least 100 feet in width from the edge of the 100-year floodplain. o A minimum vegetated buffer should be at least 35 feet in width from the edge of the 100-year floodplain. o Remove invasive species of plants. The river floodplain is naturally susceptible to weedy plant invasion and will require a sustained and targeted approach to invasive management. Aggressive invasive species along the floodplain can have a significant impact on the available habitat for the species of concern, particularly sida and river bulrush, which can occupy much the same habitat as purple loosestrife and Japanese knotweed. Control of invasive species along the river floodplain will require extensive and continual effort. Focus non-chemical control efforts on selected areas surrounding species of concern. o Target pioneer populations of invasive plants for immediate and continued removal, particularly tree-of-heaven, non-native bush honeysuckles, Japanese honeysuckle, multiflora rose and common privet. It is much easier and more effective to keep a place invasive-free than to try and repair a heavily infested habitat. o Invasive species are a significant feature of the railroad rights-of-way. However, indiscriminate use of herbicides as rights-of-way defoliants is not acceptable. A smarter, more selective use of chemical controls is required in these areas that contain both invasive species and species of concern. o Invasive species management needs to be coordinated by individuals familiar with the rare species as well as the invasive species present. o Continual invasive species monitoring and control will be necessary. o Litter removal along the shores of the river will need to be conducted on a periodic and continual basis due to the seasonal flooding regimen of the river.

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