Brunner (Lows) Island Brunner (Lows) Island – Exceptional Significance
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DEER BrunnerKEENER (Lows) RD Island West Donegal Township RIVER RD Snitz Creek MILLER 241 Lancaster County Newberry Township R Conoy Creek D L IL York County M E ON ST STAC KS TOW D Bainbridge N R ek noy C re Susquehanna River Co RIVER RD East Manchester Township (LimitAeialof imagery) (Limit of Aeial imagery) Lancaster County Natural Heritage Inventory Update 2008 Legend Species of concern core habitat Natural Heritage Area Roads Hellam Supporting Landscape PA Turnpike Township Streams All other roads Riparian Buffer Municipal Boundary Miles 0 0.5 1 1.5 2 Brunner (Lows) Island Brunner (Lows) Island – Exceptional significance PNHP Rank1 State Last Observed Species of Concern: Quality2 Global State Status1 (y-m-d) Plants: Scarlet ammannia (Ammannia coccinea) G5 S2 PE 1997-08-10 C Tooth-cup (Rotala ramosior) G5 S3 PR 1997-08-10 C Animals: Elktoe mussel (Alasmidonta marginata) G4 S4 - 2002-08-31 E Triangle floater mussel (Alasmidonta undulata) G4 S3S4 - 1999-08-06 E Yellow lampmussel (Lampsilis cariosa) G3G4 S3S4 - 2006-08-19 E Osprey (Pandion haliaetus) G5 S2B PT 2003 E Virginia Rail (Rallus limicola) G5 S3B - 1987 E Sensitive species of concern (A)3 - - - 2002 E Sensitive species of concern (B)3 - - - 2003 E Sensitive species of concern (C)3 - - - 1996-05-30 D 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 Natural Heritage Area includes the section of the Susquehanna River south of the borough of York Haven to the railroad bridge crossing the river at the mouth of Codorus Creek. Brunner Island is directly across the river from the borough of Bainbridge in Lancaster County. o Municipalities: o Conoy Township, (Lancaster County) o Hellam Township, (York County) o East Manchester Township, (York County) o Newberry Township, (York County) o York Haven Borough, (York County) o USGS Quadrangles: o York Haven Quadrangle o 1990 Lancaster Natural Areas Inventory reference: o “Haldeman Island” – (York Haven Quadrangle) Description: As Conewago Creek enters the Susquehanna River it divides into several channels and cuts the delta-like Brunner Island (the lower portion is also called Lows Island) from the main shore of York County. Brunner Island is the site of a PPL owned coal-fired electric generating plant that began operating in the early 1960s. Several other large islands occur in this section of the river including Haldeman, Ely and Pole Islands. The majority of these islands retain most of their natural conditions. This portion of the river also contains an extensive region of bedrock outcrop, referred to as Haldeman Riffles, 157 Brunner (Lows) Island which is dramatically revealed during times of seasonally low water. A public hiking trail is along the remnants of the Pennsylvania Canal. Species of Concern Considerations: Plants: o Scarlet ammannia is a globally secure (G5) though state imperiled (S2) plant that inhabits various damp to wet habitats, especially on the sandy shorelines, mudflats and intermittently flooded zones of rivers, streams, and ponds, and may also be found in human-created disturbances that simulate natural habitats. Conservation of this habitat type will help this species to persist at this location. o Tooth cup is a globally secure (G5), state rare (S3) annual plant that occupies exposed shorelines, stream margins, streambed outcrops, and other damp, open places. The populations of toothcup that occur along streams and rivers can be enhanced by maintaining the natural seasonal fluctuations in the water level of the stream and the natural conditions of its shoreline. Animals: o Ospreys have been increasing in number along the Susquehanna River and its tributaries due to a reintroduction program in the 1980s. These birds adapt readily to human activity and often construct nests on man-made structures (Brauning 1992). Being primarily fish eaters, Ospreys utilize aquatic habitats for food gathering and upland habitats or prominent features as nesting areas. The forested edge of the river, as well as the aquatic habitat of the river are both important components of this species habitat preferences. o Three freshwater mussel species of concern, elktoe, triangle floater and yellow lampmussel, along with four additional species of mussels were documented in this section of the Susquehanna River by local naturalist, Larry Coble. Historically, the dwarf wedge mussel, a federally endangered species, was also documented as occurring in the Susquehanna River near this location. Mussels are filter feeders and are strongly impacted by poor water quality and unsuitable creek bed substrate. Mussels exist as a parasite on certain fish species in their early life stage, and decreased populations of the host fish can negatively affect mussel populations. Dams that impede fish migration also restrict the habitat available to mussels. All streams, creeks and tributaries to the Susquehanna River should have wide forested/vegetated buffers in order to help ensure proper water quality for freshwater mussel habitat. Impediments to fish movement such as dams and improper stream crossings should be corrected to improve available habitat for mussels and their fish hosts. o The river is habitat for a sensitive species of concern documented over several years at this location. Maintain and improve water quality and movement above dams for fish migration to improve the habitat for this species of concern. o Two additional sensitive species of concern were documented along this stretch of the river. The core habitat for these sensitive species of concern is both the river and the adjacent upland forest. These sensitive species of concern require an abundant food source in the river and breeding areas in the adjacent upland forest. 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 and all its tributaries 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 This Natural Heritage Area is drawn relatively tightly around the river and the immediately adjacent uplands. The natural community types present represent the floodplains and upland forests in immediate proximity to the river. The dominant natural community types are: o Terrestrial (upland) communities: 158 Brunner (Lows) Island o Hemlock-tuliptree-birch forest o Tuliptree-beech-maple forest o Palustrine (wetland) communities: o Red maple-black gum palustrine forest o Red maple-elm-willow floodplain swamp o River birch-sycamore floodplain scrub o Silver maple floodplain forest o Sycamore (river birch)-box elder floodplain forest Ownership: o Most of the islands in this section of the river are privately owned. o Three small, but ecologically significant islands are owned by the Commonwealth of Pennsylvania. o A small piece of Haldeman Island and a significant portion of the eastern shore of the Susquehanna River north of Bainbridge is owned by the PPL Corporation. Habitat Disturbances: o Historic – The landscape surrounding this Natural Heritage Area was gradually cleared of its original forest cover over 200 years ago and replaced by the intensively cultivated landscape that we see today. o The borough of Bainbridge was built along the banks of the Susquehanna River. o The Pennsylvania Canal and then the Pennsylvania Railroad line were built along the eastern shore of the river and a railroad was built along the western shore of the river as well. o Numerous roads were built as infrastructure for the growing population of the area. o Most of the adjacent land in Lancaster and York counties was in agricultural production, with scattered quarry operations in 1940. o Brunner Island was almost entirely in active agricultural production based on aerial photographs taken in 1940. o The small channel that used to separate Brunner Island from Lows Island was filled. o The PPL coal-fired electric generating plant was opened on the island in 1961. o Current – o Most of the eastern and western shorelines of this section of the river fail to function as a terrestrial habitat corridor through the region. A much wider and enhanced vegetated buffer is needed adjacent to the floodplain on both shores of the Susquehanna River. While the Susquehanna River acts as a primary migratory pathway for many species of birds and bats, the vegetated area between the railroad tracks and the river is in most areas too narrow to adequately function as a regional terrestrial habitat corridor. Animals traveling northward though the extensive forested River Hills area of Lancaster County 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 Turkey Hill. Similarly, the extensively forested areas in the southwestern shore of the river in York County dissipate northward where the landscape has been converted to agricultural and urban land uses. o The habitat of Bruner Island has been almost entirely converted to industrial uses though the perimeter of the island remains vegetated. Coal piles, fill and residue cover most of the island area, which can lead to coal pile runoff and decrease river water quality. Water heated by coal to produce steam for electric generation is returned back into the river, raising the local temperature of the surrounding river water. o In contrast to some of Lancaster County’s more intensively cultivated landscapes, many of the streams and smaller tributaries to the Susquehanna River have retained moderately 159 Brunner (Lows) Island sized vegetated buffers despite the high level of agricultural conversion of the natural landscape.