introduction - Pennsylvania Natural Heritage Program

herbaceous layer is somewhat sparse, with hay-scented fern (Dennstaedtia punctilobula), floweringwintergreen (Polygala paucifolia), teaberry (Gaultheria procumbens), chestnut oak seedlings,partridgeberry (Mitchella repens), trailing arbutus (Epigaea repens), and occasional pink lady’sslipper orchids (Cypripedium acaule). The soil is sandy, and sandstone rocks are common on thesurface. Lichens and mosses are prevalent on the rocks and forest floor.The hemlock forest community occurs along the broad valley of the southeast branch of the creekbefore it turns north at its juncture with another tributary. The canopy is dominated almostexclusively by hemlock, and there is almost no herbaceous layer. There are patches of denserhododendron (Rhododendron maximum) along the floodplain and valley floor. This area has a highpotential for hosting bird species that depend upon coniferous forest habitats.Upstream and downstream of the hemlock forest is red oak – mixed hardwood forest. Downstream,the width of the stream is substantial, and the bank has occasional vegetated terraces. Speciesincluded several sedges (Carex prasina, Carex lupulina, Carex debilis, Carex folliculata), soft rush(Juncus effusus), heart-leaved aster (Eurybia divaricata), fowl manna-grass (Glyceria striata),sensitive fern (Onoclea sensibilis), marsh pennywort (Hydrocotyle americana), slender manna-grass(Glyceria melicaria), perfoliate boneset (Eupatorium perfoliatum), and New York fern (Thelypterisnoveboracensis).Upstream of the hemlock forest, the stream channel is dry, and the floodplain is broad and flat. Thecanopy includes red maple (Acer rubrum), black birch (Betula lenta), white or green ash (Fraxinusamericana or Fraxinus pensylvanica), black cherry (Prunus serotina), blue beech (Carpinuscaroliniana), and red oak (Quercus rubra). Shrubs include witch hazel (Hamamelis virginiana),(Rhododendron maximum), mountain laurel (Kalmia latifolia), lowbush blueberry (Vacciniumangustifolium), and deerberry (Vaccinium stamineum). In the herbaceous layer, New York fern(Thelypteris noveboracensis) and hay-scented fern (Dennstaedtia punctilobula) are dominant; otherspecies include: a sedge (Carex laxiflora), bellwort (Uvularia sessilifolia), rattlesnake-root(Prenanthes alba), sweet white violet (Viola blanda), downy yellow violet (Viola pubescens),American dog violet (Viola labradorica), common blue violet (Viola sororia), carrion-flower (Smilaxherbacea), wild sarsparilla (Aralia nudicaulis), intermediate wood fern (Dryopteris intermedia),northern maidenhair fern (Adiantum pedatum), Christmas fern (Polystichum acrostichoides), bishop’smitre-wort (Mitella diphylla), hog-peanut (Amphicarpa bracteata), mayapple (Podophyllumpeltatum), wild licorice (Galium circaezens), wakerobin (Trillium erectum), indian cucumber root(Medeola virginica), Canada mayflower (Maianthemum canadense), partridgeberry (Mitchellarepens), silvery glade fern (Athyrium filix-femina), running pine (Diphasiastrum digitatum), Hickey’sground pine (Lycopodium hickeyi), bristly clubmoss (Lycopodium annotinum), cinnamon fern(Osmunda cinnamomea), teaberry (Gaultheria procumbens), and pink lady’s slipper (Cypripediumacaule). On the slopes surrounding the valley, the canopy includes shagbark hickory (Carya ovata),sugar maple (Acer saccharum), and red maple (Acer rubrum); the herbaceous layer is a dense carpetof hay-scented fern (Dennstaedtia punctilobula), which can be an indicator of overbrowsing.Higher in the valley, several small channels arise from springs and seeps. In the most extensive sucharea, hemlock dominates the canopy, although hardwoods are also present. The herb layer is sparse,mainly scattered Canada mayflower (Maianthemum canadense), except in seepage areas, where thereare patches of small cinnamon- or interrupted- fern (Osmunda sp.), water horehound (Lycopus sp.),violets, starflower (Trientalis borealis), Athyrium filix-femina, and long beech fern (Phegopterisconnectilis). Seepage areas can provide breeding habitat for amphibian species such as springpeepers, wood frogs, and also may support a variety of salamander species in their adult phase.The Supporting Landscape Areas are adjacent portions of the immediate watershed that containrecovering forest or additional usages.97