introduction - Pennsylvania Natural Heritage Program

BURNSIDE TOWNSHIPThe West Branch Susquehanna River runs through Burnside Township, and all of the township fallswithin its watershed. Along the West Branch are many wetland areas; one of these is recognized as theBurnside Oxbow BDA. The landscape of the township has relatively high and contiguous forest cover:80% is forested, with 60% core habitat and 25% roadless core habitat. Almost all the waterways in thetownship are classified as impaired streams by the DEP. To maintain and improve ecological health ofthe township landscape, good conservation objectives would be forest ecosystem stewardship andremediation of water quality problems, especially in the vicinity of wetlands such as the Burnside OxbowBDA.Burnside Oxbow BDADescriptionThis BDA is designated to highlight several wetland communities and a population of featherbells(Stenanthium gramineum), a plant species of special concern in Pennsylvania. To the north and southof the confluence of Cush Creek and the West Branch Susquehanna River, there is a broad, flatfloodplain. Although today it contains several wetland areas, it is difficult to determine which ofthese are of natural origin, or how the current vegetation compares to what may have existed in thepast. The BDA surrounds two communities that appear to have natural origins.In natural condition, a broad floodplain such as this may have been forested, with wetland conditionsin seepages where the water table intersected the surface, in riparian areas directly adjacent to thewaterways, or in low-lying depressions. Today, SR 219, SR 286, and an old railroad grade crossthrough the floodplain, all built on dikes raised above the general elevation. These dikes haveinterrupted natural drainage patterns and likely increased the proportion of the area covered inwetlands by impounding water behind them. The slope above the floodplain to the north has beenstrip mined, which may have also increased the amount of water flowing into the floodplain fromseepage through the upland areas, as formerly intact rock layers are now fragmented and drain muchmore rapidly. Seepage from the mined area is clearly reaching the wetlands, as iron precipitate colorsthe water in some areas. It is also likely that the original vegetation was removed or disturbed tosome degree in most of this floodplain area; thus, what exists today is a mixture of vegetativecommunities that have re-colonized cleared areas, in conditions somewhat different than thosenaturally present, and communities that occupy natural wetland situations which have been disturbedto a lesser degree.Core Habitat Areas—One feature which is likely of natural origin is a depressional wetland betweenSR 219 and the river shore, which has the crescent-like, “oxbow,” shape that typically results whenthe course of a waterway shifts to pinch off and abandon a looping bend. The most prevalent speciesin the oxbow is rice cutgrass (Leersia oryzoides), with reed canarygrass (Phalaris arundinacea) alsointerspersed, and patches of more aquatic species scattered, including spatterdock (Nuphar advena),duck potato (Saggitaria latifolia), soft-stemmed bulrush (Schoenoplectus tabernaemontani), andAmerican bur-reed (Sparganium americanum). Other herbaceous species include short-hair sedge(Carex crinita var. crinita), swamp candles (Lysimachia sp.), flat-topped goldenrod (Euthamiagraminifolia), jewelweed (Impatiens capensis), soft rush (Juncus effusus) and a water smartweedspecies (Polygonum punctatum). Shrubs, including speckled alder (Alnus incana), smooth alder(Alnus serrulata), buttonbush (Cephalanthus occidentalis), and winterberry (Ilex verticillata),surround the oxbow and are scattered in its southern end. Some of the water here is colored orange.The forest surrounding the oxbow and stretching to the shore of the West Branch Susquehanna Riveris also notable as a relatively intact example of a floodplain forest community. As is typical of60