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Palustrine Community Descriptions

Palustrine Forests

Palustrine Woodlands

Palustrine Shrublands

Herbaceous Wetlands

Sparsely Vegetated Wetland Communities

Basin Wetland

River Floodplain

Vernal Pool

Coastal Plain

Great Lakes Region Wetland

Peatland Wetland

Emergent Wetland

Marsh Wetland

Seepage Wetland

Wetland Plant Community Key for Pennsylvania

(scientific names for plants follow Rhoads and Block 2007)

  • 1. Areas where groundwater discharges to the surface to either create a localized pool of water (seeps) or channel of flowing water (springs). These communities tend to be small and only vegetation growing within the seep or spring should be used for classification.
    SEEP GROUP
  • 1. Areas where groundwater does not discharge to the surface to create a localized pool of water (seeps) or channel of flowing water (springs).
    • 2. Vegetation covers less than 25% of total area with non-vegetated areas consisting of sand, cobbles, or bare rock. These areas are often along riparian shorelines.
      SPARSE VEGETATION GROUP
    • 2. Vegetation covers 25% or more of total area.
      • 3. Community is dominated by herbaceous or graminoid species. Woody species (shrubs and trees) cover is less than 25% of total area. This group contains types considered “persistent” and “non-persistent” wetlands.
        HERBACEOUS GROUP
      • 3. Woody species (shrubs and trees) cover is greater than 25%.
        • 4. Shrubs (woody species 5 meters tall or less) cover greater than 25% of area. Trees (woody species greater than 5 meters tall) cover less than 25% of area.
          SHRUB GROUP
        • 4. Trees (woody species greater than 5 meters tall) cover greater than 25% of area.
          • 5. Trees (woody species greater than 5 meters tall) cover 25% - 60% of area.
            WOODLAND GROUP
          • 5. Trees (woody species greater than 5 meters tall) cover greater than 60% of area.
            FOREST GROUP

SEEP GROUP

  • 1. Community occurs along bluffs or steep slopes either adjacent to streams or to Lake Erie, in northwestern Pennsylvania. The community may be dominated by shrubs or herbaceous species.
    • 2. Community occurs along the bluffs of Lake Erie. Shrub species including red-osier dogwood (Cornus sericea), alder (Alnus spp.), and willows (Salix spp.) often (but not always) provide a substantial component of the community.
      Great Lakes Bluff Seep
    • 2. Community occurs along the steep gorge bluffs along tributaries to Lake Erie. Relative cover of vegetation is dominated by forbs and grasses.
      River Bluff Seep
  • 1. Community occurs in variety of settings but not typically along bluffs or steep slopes either adjacent to streams or to Lake Erie in northwestern Pennsylvania. Relative herbaceous cover typically contains golden saxifrage (Chrysosplenium americanum).
    • 3. Groundwater forms a distinct channel. Relative herbaceous cover is dominated by golden saxifrage (Chrysosplenium americanum), Pennsylvania bittercress (Cardamine pensylvanica), and watercress (Nasturtium officinale). Horsetails (Equisetum spp.) may also be present.
      Golden Saxifrage – Pennsylvania Bittercress Spring Run
    • 3. Groundwater has a diffuse flow, resulting in a broad area of muck soils or small ponds where the groundwater emerges.
      • 4. Community occurs in seeps underlain by serpentine bedrock. Relative cover for herbaceous layer is dominated by some combination of the following: tufted hairgrass (Deschampsia cespitosa), rice cutgrass (Leersia oryzoides), New York ironweed (Vernonia noveboracensis), slender spike-rush (Eleocharis tenuis), and deer-tongue grass (Dichanthelium clandestinum) are common.
        Serpentine Seepage Wetland
      • 4. Community does not occur in seeps underlain by serpentine bedrock. Skunk cabbage (Symplocarpus foetidus) is typically present from April to late-May. These are often small patch wetland communities that are embedded in other types, often closed-canopy terrestrial forests.
        • 5. Relative herbaceous cover is dominated by sedges (Carex spp.), Pennsylvania bittercress (Cardamine pensylvanica), golden saxifrage (Chrysosplenium americanum), golden ragwort (Packera aurea), and skunk cabbage (Symplocarpus foetidus).
          Golden Saxifrage – Sedge Rich Seep
        • 5. Relative herbaceous cover is dominated by skunk cabbage (Symplocarpus foetidus), golden saxifrage (Chrysosplenium americanum), and cinnamon fern (Osmunda cinnamomea).
          Skunk-cabbage - Golden Saxifrage Seep

SPARSE VEGETATION GROUP

  • 1. Community occurs along river and stream shores/bars or along lakeshores. Substrate is composed of cobbles, sand, or gravel.
    • 2. Community occurs along the floodplains of rivers where ice or flooding have scoured the vegetation.
      • 3. Substrate is predominantly exposed bedrock or large boulders with plants growing in soil that accumulates within bedrock cracks. Shrubs are scattered and may include willows (Salix spp.), sevenbark (Hydrangea arborescens), smooth azalea (Rhododendron arborescens), swamp azalea (Rhododendron viscosum), rosebay (Rhododendron maximum), buttonbush (Cephalanthus occidentalis), and swamp rose (Rosa palustris). Trees, such as sycamore (Platanus occidentalis), silver maple (Acer saccharinum), may be present as young saplings or as battered, stunted individuals of variable age. Common herbaceous species include Indian-grass (Sorghastrum nutans), big bluestem (Andropogon gerardii), freshwater cordgrass (Spartina pectinata), Indian-hemp (Apocynum cannabinum), and/or royal fern (Osmunda regalis).
        Floodplain Scour Community
      • 3. Substrate is variable, primarily sand, gravel, or cobble of river and stream shores/bars or along lakeshores. Some trees and shrubs such as sycamore (Platanus occidentalis), silver maple (Acer saccharinum), willows (Salix spp.), and alders (Alnus spp.) may be present as young saplings or as battered, stunted individuals of variable age. Herbaceous layer is typically dominated by smartweeds (Persicaria spp.), umbrella sedges (Cyperus spp.), blue vervain (Verbena hastata), purple loosestrife (Lythrum salicaria), common cocklebur (Xanthium strumarium), and other common annuals and short lived perennial plant species.
        Periodically Exposed Shoreline
    • 2. Community occurs only along the shoreline of Lake Erie.
      • 4. Community occurs on the unvegetated cobble and gravel shores of Lake Erie. The vegetation is sparse (usually less than 25% total cover). The community may include American beachgrass (Ammophila breviligulata), sea-rocket (Cakile edentula), beach pea (Lathyrus japonicus), and silverweed (Potentilla anserina).
        Great Lakes Sparsely Vegetated Shore
      • 4. Community occurs typically along saturated sandy flats, primarily on Presque Isle, in Erie County but may be found in small patches along the entire Lake Erie Coast of Pennsylvania. Relative cover for herbaceous layer is variable, and is mostly dominated by rushes (Juncus spp.) and umbrella sedges (Cyperus spp.).
        Great Lakes Palustrine Sandplain
  • 1. Community occurs in small upland depressions beneath a canopy of overstory trees rooted in the surrounding upland area. Substrate can be leaf litter, muck, or bare soil and is often saturated. There is usually standing water present during the growing season.
    Sparsely Vegetated Vernal Pool Community

HERBACEOUS GROUP

  • 1. Community is dominated by graminoid species (grasses, sedge, rushes). Herbs may be present but graminoid species represent a higher vegetative cover.
    • 2. Community is dominated by bulrush species (Schoenoplectus spp.) in near monotypic clones: great bulrush (Schoenoplectus tabernaemontani), and/or hardstem bulrush (Schoenoplectus acutus), or less commonly by chairmaker's rush (Schoenoplectus pungens), a bulrush (Schoenoplectus purshianus), river bulrush (Schoenoplectus fluviatilis), or Torrey's bulrush (Schoenoplectus torreyi).
      Bulrush Marsh
    • 2. Community is dominated by graminoid species other than bulrush species, primarily grasses (Poaceae) and/or sedges (Cyperaceae).
      • 3. Community occurs on river floodplains.
        • 4. Relative cover for herbaceous layer is dominated by one of the following: canary-grass (Phalaris arundinacea), Canada bluejoint (Calamagrostis canadensis), big bluestem (Andropogon gerardii), Indian-grass (Sorghastrum nutans), or common reed (Phragmites australis ssp. australis).
          • 5. Relative cover for herbaceous layer is dominated by reed canary-grass (Phalaris arundinacea) and/or Canada bluejoint (Calamagrostis canadensis).
            • 6. Almost a monotypic stand of reed canary-grass (Phalaris arundinacea), may contain some other herb or grass species but clearly dominated by reed canary grass. Community typically occurs along floodplains.
              Reed Canary-grass Floodplain Grassland
            • 6. Dominated by a combination of reed canary-grass (Phalaris arundinacea) and Canada bluejoint (Calamagrostis canadensis). Community occurs in marshes within river backwaters or upland depressions.
              Bluejoint – Reed Canary-grass Marsh
          • 5. Relative cover for herbaceous layer is dominated by big bluestem (Andropogon gerardii), Indian-grass (Sorghastrum nutans), or common reed (Phragmites australis ssp. australis).
            • 7. Relative cover for herbaceous layer is dominated by a combination of big bluestem (Andropogon gerardii), Indian-grass (Sorghastrum nutans) and/or switchgrass (Panicum virgatum). Community typically occurs along the scour zone of floodplains or islands.
              Big Bluestem - Indian-grass Floodplain Grassland
            • 7. Herbaceous layer is almost a monotypic stand of common reed (Phragmites australis ssp. australis). Other herb or grass species may be present but the community is clearly dominated by common reed. Community occurs in various settings.
              Common Reed Marsh
        • 4. Relative cover for herbaceous layer is dominated by hairy-fruited sedge (Carex trichocarpa) or twisted sedge (Carex torta).
      • 3. Community occurs in headwater basins, upland depressions or seeps.
        • 9. Vegetation rooted in a substrate consisting of either mineral soil or a thin layer of organic material (muck) over mineral soil.
          • 10. Relative cover for herbaceous layer is greater than 75% for sedges (Carex spp.).
            • 11. Relative cover for herbaceous layer is dominated by tussock sedge (Carex stricta). Other species may be present but tussock sedge is the clear dominate herbaceous species.
              Tussock Sedge Marsh
            • 11. Relative cover for herbaceous layer is dominated by a combination of several sedges such as bog sedge (Carex sterilis), prairie sedge (Carex prairea), a sedge (Carex lacustris), or yellow sedge (Carex flava). Tussock sedge (Carex stricta) may be present but community is not a monotypic layer of tussock sedge. Calciphilic species such as grass of grass-of-Parnassus (Parnassia glauca) may be present.
              Sedge - Mixed Forb Fen
          • 10. Relative cover for herbaceous layer is dominated by both grasses and sedges (Carex spp.). Sedge cover is less than 75%.
            • 12. Community occurs on seeps underlain by serpentine bedrock. Relative cover for herbaceous layer is dominated by some combination of the following: tufted hairgrass (Deschampsia cespitosa), rice cutgrass (Leersia oryzoides), New York ironweed (Vernonia noveboracensis), slender spike-rush (Eleocharis tenuis), and deer-tongue grass (Dichanthelium clandestinum).
              Serpentine Seepage Wetland
            • 12. Community is not underlain by serpentine bedrock.
              • 13. Relative cover for herbaceous layer is dominated by reed canary-grass (Phalaris arundinacea), Canada bluejoint (Calamagrostis canadensis), or common reed (Phragmites australis).
                • 14. Relative cover for herbaceous layer is dominated by reed canary-grass (Phalaris arundinacea) and/or Canada bluejoint (Calamagrostis canadensis). Community occurs in marshes within river backwaters or upland depressions.
                  Bluejoint – Reed Canary-grass Marsh
                • 14. Herbaceous layer is almost a monotypic stand of common reed (Phragmites australis). Other herb or grass species may be present but the community is clearly dominated by common reed.
                  Common Reed Marsh
              • 13. Relative cover for herbaceous layer is not dominated by reed canary-grass (Phalaris arundinacea), Canada bluejoint (Calamagrostis canadensis), or common reed (Phragmites australis).
                • 15. Community is located in small upland depressions that are seasonally inundated; shrubs may or may not be present. The margin of the wetland’s basin may or may not be distinguishable.
                  • 16. The community is composed of herbaceous species only; composition is variable. Relative cover is composed of the following: rice cutgrass (Leersia oryzoides), mannagrass (Glyceria spp.), three-way sedge (Dulichium arundinaceum var. arundinaceum), sedges (Carex spp.), or bulrushes (Scirpus spp.). Other common species include bugleweed (Lycopus uniflorus), smartweeds (Persicaria spp.), marsh fern (Thelypteris palustris), Joe-Pye-weed (Eutrochium spp.), cinnamon fern (Osmunda cinnamomea), and royal fern (Osmunda regalis).
                    Rice Cutgrass – Bulrush Vernal Pool
                  • 16. Community is dominated by a combination of herbaceous and shrubby plant species; wool-grass (Scirpus cyperinus) is usually dominant. Associate species include floating mannagrass (Glyceria septentrionalis), rattlesnake mannagrass (Glyceria canadensis), rice cutgrass (Leersia oryzoides), pale meadowgrass (Torreyochloa pallida), sedges (e.g. Carex crinita, C. lurida, C. lupulina, C. vesicaria, C. folliculata), three-way sedge (Dulichium arundinaceum), mild water-pepper (Persicaria hydropiperoides), marsh-purslane (Ludwigia palustris), marsh St. Johns-wort (Triadenum fraseri). Shrubs include hardhack (Spiraea tomentosa), meadow-sweet (S. alba), northern arrow-wood (Viburnum recognitum), highbush blueberry (Vaccinium corymbosum), and buttonbush (Cephalanthus occidentalis).
                    Wool-grass – Mannagrass Mixed Shrub Vernal Pool
                • 15. Community is not located in a small, isolated upland depression that is seasonally inundated, but rather community occurs in what can be described as a moist field, ditch, or low-lying area; shrubs may or may not be present. Relative cover for herbaceous layer is dominated by a combination of sedges, grasses and forbs. Sedge species present are usually common in Pennsylvania.
                  Mixed Forb - Graminoid Wet Meadow
        • 9. Community composed of vegetation rooted in a substrate consisting of moss or sedge peat.
          • 17. Community is dominated by one or a combination of the following: tussock sedge (Carex stricta), prairie sedge (Carex prairea), many-fruited sedge (Carex lasiocarpa), or a sedge (Carex lacustris). Other species will be present but the clear dominant species are the sedges above.
            • 18. Community is dominated by tussock sedge (Carex stricta) often in near monotypic stands. Community typically consists of well-developed sedge tussocks interspersed with standing water over organic muck soils.
              Tussock Sedge Marsh
            • 18. Community composition is variable, often dominated by sedges such as Atlantic sedge (Carex sterilis), prairie sedge (Carex prairea), a sedge (Carex lacustris), and yellow sedge (Carex flava), or cotton-grass (Eriophorum virginicum) and/or white beak-rush (Rhynchospora alba). Tussock sedge (Carex stricta) may be present but community is not a monotypic layer of tussock sedge.
              • 19. Plant community is dominated by calciphilic sedge species such as Atlantic sedge (Carex sterilis), sedge (Carex tetanica), and yellow sedge (Carex flava). Substrate consists of sedge or sphagnum peat. Other calcareous indicators including grass of grass-of-Parnassus (Parnassia glauca) and mountain-mint (Pycnanthemum virginianum) may be present. Community is influenced by calcium-rich groundwater. Surface water pH is between 6.0 and 7.9 during the growing season.
                Sedge - Mixed Forb Fen
              • 19. Plant community is not dominated by calciphilic sedge species; relative cover of sedge species is variable. Community may or may not be influenced by groundwater. Surface water pH is between 3.5 and 5.5 during the growing season. Typically peat moss (Sphagnum spp.) is abundant, often forming a dense mat beneath the vascular flora.
                • 20. Community is dominated by many-fruited sedge (Carex lasiocarpa). Flat-leaved bladderwort (Utricularia intermedia) is also a characteristic species. Other associated species may include a sedge (Carex lacustris), marsh cinquefoil (Potentilla palustris), tussock sedge (Carex stricta), and marsh fern (Thelypteris palustris). Substrate consists of a deep layer of decomposed sedge-peat.
                  Many-Fruited Sedge - Bladderwort Poor Fen
                • 20. Community is dominated by tawny cotton-grass (Eriophorum virginicum) and/or white beak-rush (Rhynchospora alba). Pitcher-plant (Sarracenia purpurea) or sundew (Drosera spp.) are typically present.
                  • 21. Community is dominated by white beak-rush (Rhynchospora alba) and peat mosses (Sphagnum spp.). Acid-indicators are usually present including round-leaved sundew (Drosera rotundifolia), spatulate-leaved sundew (Drosera intermedia), and pitcher-plant (Sarracenia purpurea). Cotton-grass (Eriophorum vaginatum), and tawny cotton-grass (Eriophorum virginicum) are typically present but at lower coverage. Cranberry (Vaccinium macrocarpon) and small cranberry (Vaccinium oxycoccos) are abundant in some areas. The pH of the surface water is low (3.5-4.0) and there is little groundwater influence. Community typically associated with a floating mat.
                    Sphagnum – Beak-Rush Peatland
                  • 21. Plant species can be variable, but is usually dominated by tawny cotton-grass (Eriophorum virginicum), white beak-rush (Rhynchospora alba), a sedge (Carex trisperma), and a sedge (Carex folliculata). Other species include soft rush (Juncus effusus), narrow-panicled rush (Juncus brevicaudatus), cinnamon fern (Osmunda cinnamomea), round-leaved sundew (Drosera rotundifolia), and wool-grass (Scirpus cyperinus). The pH of the surface water is low (4.0 – 5.0); however, the community is often influenced by groundwater. Community is seldom part of a floating mat. Community patch may include remnant tree stumps and other evidence of historic logging.
                    Cotton-grass Poor Fen
  • 1. Community is dominated by forbs. Graminoid species may be present but forbs represent a higher vegetative cover.
    • 22. Communities of river floodplains and tidal marshes; vegetation composition variable.
      • 23. Vegetation is rooted in substrates that are periodically flooded and may remain saturated, but is above the mean water level.
        • 24. Vegetation is a monotypic stand of Japanese knotweed (Fallopia japonica).
          Japanese Knotweed Floodplain Thicket
        • 24. Vegetation is not a monotypic stand of Japanese knotweed (Fallopia japonica).
          • 25. Vegetation is variable; community occurs along lower floodplain terraces experiencing periodic flooding; may grade into other floodplain communities. Type may represent openings in floodplain forests, dominated by herbaceous species. The relative cover for herbaceous layer may be dominated by goldenrods (Solidago spp.) and wingstem (Verbesina alternifolia). Characteristic species include species associated with river floodplain ecosystems: reed canary-grass (Phalaris arundinacea), common sneezeweed (Helenium autumnale), twisted sedge (Carex torta), cardinal-flower (Lobelia cardinalis), smartweeds (Persicaria spp.), blue vervain (Verbena hastata), bulrush (Scirpus polyphyllus), and big bluestem (Andropogon gerardii).
            Floodplain Meadow
          • 25. Vegetation is variable; community occurs along higher floodplain terraces that are flooded only in the most extreme flood events; may grade into upland forest and shrubland communities. Relative cover for herbaceous layer is dominated by a combination of sedges, grasses and forbs common in Pennsylvania.
            Mixed Forb - Graminoid Wet Meadow
      • 23. Vegetation is rooted in substrates that are nearly permanently flooded or saturated throughout the growing season; standing or flowing water is present except during annual periods of low flow, tidal fluctuation, or where water has been artificially drawn down.
        • 26. Community occurs along freshwater intertidal zone of the Coastal Plain.
          • 27. Occurs on gradually sloping river banks in the zone between low tide and mean high tide. Vegetation is typically separated into three zones. The uppermost zone includes wild-rice (Zizania aquatica), salt-marsh water-hemp (Amaranthus cannabinus), swamp beggar-ticks (Bidens bidentoides), showy bur-marigold (Bidens laevis), pickerel-weed (Pontederia cordata), arrow-arum (Peltandra virginica), and dotted smartweed (Persicaria punctata). The middle zone is dominated by chairmaker’s rush (Schoenoplectus pungens), spatter-dock (Nuphar advena and N. variegata), long-lobed arrowhead (Sagittaria calycina), arrowhead (Sagittaria rigida), mud-plantain (Heteranthera multiflora), and Smith’s bulrush (Schoenoplectus smithii). The lowest vegetated zone is an exposed mudflat at low tide; subulate arrowhead (Sagittaria subulata) is often present along with true aquatic species.
            Riverbank Freshwater Tidal Marsh
          • 27. Occurs on areas of low-lying, nearly level land adjacent to the upper edge of the sloping river bank. No clear zonation of vegetation. Relative cover for herbaceous layer is dominated by wild-rice (Zizania aquatica), swamp beggar’s-ticks (Bidens bidentoides), showy bur-marigold (Bidens laevis), and salt-marsh water-hemp (Amaranthus cannabinus). Numerous, more widespread wetland plants may also be present such as sweet flag (Acorus calamus), common cat-tail (Typha latifolia), arrow-arum (Peltandra virginica), pickerelweed (Pontederia cordata), wapato (Sagittaria latifolia), dotted smartweed (Persicaria punctata), halberd-leaf tearthumb (Persicaria arifolia), marsh-purslane (Ludwigia palustris), rice cutgrass (Leersia oryzoides), jewelweed (Impatiens capensis), sensitive fern (Onoclea sensibilis), rose-mallow (Hibiscus moscheutos), and climbing hempweed (Mikania scandens).
            Freshwater Tidal Mixed High Marsh
        • 26. Community does not occur along intertidal zone of the Coastal Plain.
          • 28. Community is composed of non-persistent emergent vegetation that occurs in inundated depressions along lakeshores or riparian zones, usually in sloughs. The appearance of these systems changes seasonally from nearly unvegetated substrate in winter and early spring, to dense vegetation during the height of the growing season. Substrate is muck and usually flooded throughout the growing season. Relative cover for herbaceous layer is dominated by spatterdock (Nuphar advena and N. variegata ) and fragrant water-lily (Nymphaea odorata), or pickerel-weed (Pontederia cordata), arrow-arum (Peltandra virginica), wapato (Sagittaria latifolia var. latifolia).
            • 29. Relative cover for herbaceous layer is dominated by spatterdock (Nuphar advena and N. variegata) and fragrant water-lily (Nymphaea odorata). Water smartweed (Persicaria amphibia), rice cutgrass (Leersia oryzoides), arrow-arum (Peltandra virginica), and wapato (Sagittaria latifolia) are typically present at lower cover.
              Spatterdock - Water-lily Emergent Wetland
            • 29. Relative cover for herbaceous layer is dominated by pickerel-weed (Pontederia cordata), arrow-arum (Peltandra virginica), and wapato (Sagittaria latifolia).
              Pickerel-weed - Arrow-arum - Arrowhead Emergent Wetland
          • 28. Community is composed of persistent emergent vegetation that occurs in inundated depressions along lakeshores or riparian zones (often in sloughs) or on gravel and cobble bars within the stream channel. Relative cover for herbaceous layer is dominated by either near monotypic stands of cat-tails (Typha spp.), water-willow (Justicia americana) or lizard’s-tail (Saururus cernuus) or is composed of a wide variety of persistent emergent plant species.
            • 30. Community is dominated by either water-willow (Justicia americana) or lizard’s-tail (Saururus cernuus).
            • 30. Vegetation composition of community is variable, either dominated by cat-tail species (Typha spp.) or a wide variety of persistent emergent plant species. Plants rooted in flooded substrate, usually by standing or ponded water.
              • 32. Herbaceous cover is almost a monotypic stand of cat-tail species (Typha spp.).
                Cat-tail Marsh
              • 32. Relative cover for herbaceous layer is variable; characteristic species include three-way sedge (Dulichium arundinaceum var. arundinaceum), halberd-leaved tearthumb (Persicaria arifolia), tearthumb (Persicaria sagittata), rushes (Juncus spp.), beggar-ticks (Bidens sp.), and sensitive fern (Onoclea sensibilis).
                Mixed Forb Marsh
    • 22. Communities of basin wetlands and upland depressions; vegetation composition variable.
      • 33. Vegetation composition of community is variable, either dominated by cat-tail species (Typha spp.) or a wide variety of persistent emergent plant species. Plants rooted in flooded substrate, usually by standing or ponded water.
        • 34. Herbaceous cover is almost a monotypic stand of cat-tail species (Typha spp.). Community may occur in standing water.
          Cat-tail Marsh
        • 34. Herbaceous cover not a monotypic stand of cat-tail species (Typha spp.). Relative cover for herbaceous layer is variable. Community occurs in moist or saturated low areas of the uplands, or at the margins of permanent water bodies
          • 35. Community occurs along lake margins, flooded depressions, and other wetlands that remain inundated throughout the growing season. Composition is variable and includes aquatic emergent plants as well as submerged aquatic species. Species include three-way sedge (Dulichium arundinaceum var. arundinaceum), halberd-leaf tearthumb (Persicaria arifolia), tearthumb (Persicaria sagittata), tearthumb (Persicaria sagittata), Joe-Pye-weed (Eutrochium spp.), rushes (Juncus spp.), beggar-ticks (Bidens spp.), sensitive fern (Onoclea sensibilis), marsh St. John's-wort (Triadenum virginicum), arrowhead (Sagittaria rigida), wapato (Sagittaria latifolia), dock (Rumex spp.), sharp-fruited rush (Juncus acuminatus), jewelweed (Impatiens capensis), tussock sedge (Carex stricta), sweet flag (Acorus calamus), rice cutgrass (Leersia oryzoides).
            Mixed Forb Marsh
          • 35. Community occurs on substrates that are saturated or inundated early in the growing season, but may be dry by mid- to late-summer. Composition is variable, but herbaceous species dominate. Species include goldenrods (Solidago spp.), rice cutgrass (Leersia oryzoides), wool-grass (Scirpus cyperinus), bugleweed (Lycopus uniflorus), smartweeds (Polygonum and Persicaria spp.), sedges (Carex stipata var. stipata, C. canescens, C. lurida, C. cristatella, C. tribuloides, and C. vesicaria), tussock sedge (C. stricta), soft rush (Juncus effusus), Joe-Pye-weed (Eutrochium spp.), New York ironweed (Vernonia noveboracensis), reed canary-grass (Phalaris arundinacea), and bulrush (Scirpus spp.). Scattered shrubs may be present, representative species include steeplebush (Spiraea tomentosa), silky dogwood (Cornus amomum), gray dogwood (Cornus racemosa), red-osier dogwood (Cornus sericea), and arrow-wood (Viburnum recognitum).
            Mixed Forb – Graminoid Wet Meadow
      • 33. Community is composed of non-persistent emergent vegetation that occurs in inundated depressions along lakeshores or pond margins, and wet depressions. Relative cover for herbaceous layer is dominated by spatterdock (Nuphar advena and N. variegata ) and fragrant water-lily (Nymphaea odorata), or pickerel-weed (Pontederia cordata), arrow-arum (Peltandra virginica), wapato (Sagittaria latifolia). The appearance of these systems changes seasonally from nearly unvegetated substrate in winter and early spring, to dense vegetation during the height of the growing season. Substrate is muck and usually saturated throughout the growing season.
        • 36. Relative cover for herbaceous layer is dominated by spatterdock (Nuphar advena and N. variegata) and fragrant water-lily (Nymphaea odorata). Water smartweed (Persicaria amphibia), arrow-arum (Peltandra virginica) and wapato (Sagittaria latifolia) are typically present at lower cover. Community is typically semi-inundated.
          Spatterdock - Water-lily Emergent Wetland
        • 36. Relative cover for herbaceous layer is dominated by pickerel-weed (Pontederia cordata), arrow-arum (Peltandra virginica), and wapato (Sagittaria latifolia).
          Pickerel-weed - Arrow-arum - Arrowhead Emergent Wetland

SHRUBLAND GROUP

  • 1. Riparian vegetation found along floodplains on islands, shorelines, gravel bars, or riverbeds. Relative cover for shrub layer is dominated by either alders (Alnus spp.), willows (Salix spp.), dogwoods (Cornus spp.), water-willow (Decodon verticillatus), bayberry (Myrica spp.), buttonbush (Cephalanthus occidentalis), sycamore (Platanus occidentalis), silver maple (Acer saccharinum), or river birch (Betula nigra).
    • 2. Relative cover for shrub layer is dominated by some combination of sycamore (Platanus occidentalis), silver maple (Acer saccharinum), eastern cottonwood (Populus deltoides), river birch (Betula nigra), and black willow (Salix nigra).
      Mixed Hardwood Floodplain Thicket
    • 2. Relative cover for shrub layer is dominated by either alders (Alnus spp.), willows (Salix spp.), dogwoods (Cornus spp.), bayberry (Myrica pensylvanica), water-willow (Decodon verticillatus), or buttonbush (Cephalanthus occidentalis).
      • 3. Relative cover for shrub layer is greater for alders (Alnus spp.) than willows (Salix spp.). Shrub layer is dominated by speckled alder (Alnus incana ssp. rugosa) and smooth alder (Alnus serrulata) with a combination of black willow (Salix nigra), ninebark (Physocarpus opulifolius), or silky dogwood (Cornus amomum). Water-willow (Decodon verticillatus) or buttonbush (Cephalanthus occidentalis) are absent or scattered throughout.
        Alder - Dogwood Floodplain Thicket
      • 3. Relative cover for shrub layer is dominated by willows (Salix spp.), dogwoods (Cornus spp.), bayberry (Myrica pensylvanica), water-willow (Decodon verticillatus), or buttonbush (Cephalanthus occidentalis). Alders (Alnus spp.) are either co-dominant or absent.
        • 4. Community is found along scour zones or island heads along major rivers. Sandbar willow (Salix exigua) and black willow (Salix nigra) are typically the dominant short shrubs (<2m in height), with occasional sycamore (Platanus occidentalis), river birch (Betula nigra), silver maple (Acer saccharinum), box-elder (Acer negundo), hardhack (Spiraea tomentosa), silky dogwood (Cornus amomum), and honey-locust (Gleditsia triacanthos). Herbaceous species may include: Indian-grass (Sorghastrum nutans), big bluestem (Andropogon gerardii), Indian hemp (Apocynum cannabinum), smartweeds (Persicaria spp.), or pink dogbane (Apocynum androsaemifolium).
          Willow – Indian-grass Floodplain Shrub Wetland
        • 4. Community typically occurs along shorelines, back channels, or tributaries.
          • 5. Black willow (Salix nigra) is clearly the dominant shrub species with alder (Alnus spp.), dogwoods (Cornus spp.), and other willows (Salix spp.) typically present. Herbaceous layer is varaible but ususally includes smartweeds (Persicaria spp.), beggar-ticks (Bidens spp.), and/or reed canary-grass (Phalaris arundinacea).
            Black Willow Floodplain Thicket
          • 5. Relative cover is not dominated by black willow (Salix nigra).
            • 6. Dominant species include one or a combination of the following: bayberry (Myrica pensylvanica), willows (Salix spp.), dogwoods (Cornus spp.), and/or meadow-sweet (Spiraea spp.).
              • 7. Dominant species include bayberry (Myrica pensylvanica), silky dogwood (Cornus amomum), red-osier dogwood (Cornus sericea), and willows (Salix spp.), with scattered eastern cottonwood (Populus deltoides) and European white birch (Betula pendula). This community is found only on Presque Isle within the Great Lakes region of Pennsylvania.
                Great Lakes Bayberry - Mixed Shrub Wetland
              • 7. Dominant species include one or a combination of the following: willows (Salix spp.), dogwoods (Cornus spp.), and/or meadow-sweet (Spiraea spp.). Other shrub species, such as northern arrow-wood (Viburnum recognitum) and alders (Alnus spp.) may also be present as associate species.
                Circumneutral Mixed Shrub Wetland
            • 6. Relative cover for shrub layer is dominated by water-willow (Decodon verticillatus) or buttonbush (Cephalanthus occidentalis).
              • 8. Relative cover for shrub layer is dominated by water-willow (Decodon verticillatus), although buttonbush (Cephalanthus occidentalis) may be present but is not dominant.
                Water-willow (Decodon verticillatus) Shrub Wetland
              • 8. Relative cover for shrub layer is dominated by buttonbush (Cephalanthus occidentalis) although water-willow (Decodon verticillatus) may be present but is not dominant.
                Buttonbush Wetland
  • 1. Palustine vegetation found in basin depressions. Relative cover for shrub layer is dominated by either leatherleaf (Chamaedaphne calyculata var. angustifolia), alders (Alnus spp.), swamp rose (Rosa palustris), dogwoods (Cornus spp.), willows (Salix spp.), meadow-sweet (Spiraea spp.), winterberry (Ilex verticillata), mountain holly (Ilex mucronata), highbush blueberry (Vaccinium corymbosum), buckthorn (Rhamnus spp.), eastern red-cedar (Juniperus virginiana), poison sumac (Toxicodendron vernix), bayberry (Myrica spp.), water-willow (Decodon verticillatus), or buttonbush (Cephalanthus occidentalis).
    • 9. Relative cover for shrub layer is dominated by either leatherleaf (Chamaedaphne calyculata var. angustifolia), alders (Alnus spp.), winterberry (Ilex verticillata), mountain holly (Ilex mucronata), highbush blueberry (Vaccinium corymbosum), swamp rose (Rosa palustris), dogwoods (Cornus spp.), willows (Salix spp.), or meadow-sweet (Spiraea spp.).
      • 10. Relative cover for shrub layer is mainly dominated by leatherleaf (Chamaedaphne calyculata var. angustifolia).
        • 11. Leatherleaf is typically under 0.3 meters in height.
          • 12. Leatherleaf (Chamaedaphne calyculata var. angustifolia), sedges (Carex spp.), and sphagnum moss (Sphagnum spp.) dominate the community. This community usually occurs in upland depressions influenced by impoundments or may be present in glacial bogs.
            Leatherleaf – Sedge Wetland
          • 12. Leatherleaf (Chamaedaphne calyculata var. angustifolia) is stunted and intermixed with cranberry species (Vaccinium oxycoccos and Vaccinium macrocarpon), and sphagnum moss (Sphagnum spp.). This community often represents the zone of rooted vegetation adjacent to open water (i.e. bog lake) and may grade into the Leatherleaf - Bog Rosemary Bog type.
            Leatherleaf - Cranberry Bog
        • 11. Leatherleaf (Chamaedaphne calyculata var. angustifolia) is over 0.3 meters in height.
          • 13. Leatherleaf (Chamaedaphne calyculata var. angustifolia), sedges (Carex spp.), and sphagnum moss (Sphagnum spp.) dominate the community. This community usually occurs in upland depressions influenced by impoundments or may be present in glacial bogs.
            Leatherleaf – Sedge Wetland
          • 13. Leatherleaf (Chamaedaphne calyculata var. angustifolia) is intermixed with other shrub species.
            • 14. Leatherleaf (Chamaedaphne calyculata var. angustifolia) is dominant or co-dominant with sweet-gale (Myrica gale) and shrubs are nearly waist high and very dense. Other low shrubs like rhodora (Rhododendron canadense), sheep laurel (Kalmia angustifolia), chokeberry (Photinia spp.), and bog laurel (Kalmia polifolia) are common. Sphagnum moss (Sphagnum spp.) is typically present.
              Sweet-gale – Leatherleaf Shrub Fen
            • 14. Leatherleaf (Chamaedaphne calyculata var. angustifolia) is dominant shrub species but is intermixed with sheep laurel (Kalmia angustifolia), bog-rosemary (Andromeda polifolia var. glaucophylla), chokeberry (Photinia spp.), black huckleberry (Gaylussacia baccata), and Labrador tea (Rhododendron groenlandicum).
              Leatherleaf - Bog Rosemary Bog
      • 10. Relative cover for shrub layer is mainly dominated by swamp rose (Rosa palustris), dogwoods (Cornus spp.), willows (Salix spp.), meadow-sweet (Spiraea spp.), alder (Alnus spp.), winterberry (Ilex verticillata), mountain holly (Ilex mucronata), or highbush blueberry (Vaccinium corymbosum).
        • 15. Relative cover is dominated by one or a combination of swamp rose (Rosa palustris), dogwoods (Cornus spp.), willows (Salix spp.), or meadow-sweet (Spiraea spp.). Other shrub species, such as northern arrow-wood (Viburnum recognitum) and alders (Alnus spp.) may also be present as associate species.
          Circumneutral Mixed Shrub Wetland
        • 15. Relative cover is clearly dominated by either alders (Alnus spp.), winterberry (Ilex verticillata), mountain holly (Ilex mucronata), or highbush blueberry (Vaccinium corymbosum).
          • 16. Relative cover for shrub layer is mainly dominated by either smooth alder (Alnus serrulata), speckled alder (Alnus incana ssp. rugosa), winterberry (Ilex verticillata), or mountain holly (Ilex mucronata).
            • 17. Relative cover is dominated by a combination of alders (Alnus spp.), willows (Salix spp.), dogwoods (Cornus spp.), American elder (Sambucas canadensis), buttonbush (Cephalanthus occidentalis), and water-willow (Decodon verticillatus). Sphagnum moss (Sphagnum spp.) is generally absent although other mosses may be present.
              Circumneutral Mixed Shrub Wetland
            • 17. Relative cover is dominated by a combination of alders (Alnus spp.), maleberry (Lyonia ligustrina), winterberry (Ilex verticillata), mountain holly (Ilex mucronata), highbush blueberry (Vaccinium corymbosum), and/or leatherleaf (Chamaedaphne calyculata var. angustifolia). Sphagnum moss (Sphagnum spp.) and sedges (Carex spp.) dominate the herbaceous layer.
              Acidic Mixed Shrub – Sphagnum Wetland
          • 16. Relative cover for shrub layer is mainly dominated by highbush blueberry (Vaccinium corymbosum).
            • 18. In addition to highbush blueberry (Vaccinium corymbosum); meadow-sweet (Spirea spp.) is present and herbaceous layer contains very little to no sphagnum moss (Sphagnum spp.).
              Highbush Blueberry – Meadow-sweet Wetland
            • 18. In addition to highbush blueberry (Vaccinium corymbosum); cinnamon fern (Osmunda cinnamomea), sphagnum moss (Sphagnum spp.), and sedges (Carex spp.) dominate the herbaceous layer.
              Highbush Blueberry – Sphagnum Wetland
    • 9. Relative cover for shrub layer is dominated by either buckthorn (Rhamnus spp.), eastern red-cedar (Juniperus virginiana), poison sumac (Toxicodendron vernix), water-willow (Decodon verticillatus), buttonbush (Cephalanthus occidentalis), or bayberry (Myrica spp.).
      • 19. Relative cover for shrub layer is dominated by either buckthorn (Rhamnus spp.),eastern red-cedar (Juniperus virginiana), poison sumac (Toxicodendron vernix), or bayberry (Myrica pensylvanica).
        • 20. Relative shrub cover is dominated by bayberry (Myrica pensylvanica).
          • 21. Dominant species include bayberry (Myrica pensylvanica), silky dogwood (Cornus amomum), red-osier dogwood (Cornus sericea), and willows (Salix spp.), with scattered eastern cottonwood (Populus deltoides). This community is found only on Presque Isle within the Great Lakes region of Pennsylvania.
            Great Lakes Bayberry - Mixed Shrub Wetland
          • 21. Relative cover for shrub layer is dominated by a combination of eastern red-cedar (Juniperus virginiana), poison sumac (Toxicodendron vernix), or bayberry (Myrica pensylvanica). Shrubby cinquefoil (Potentilla fruticosa) is often present.
            Poison Sumac – Red-cedar – Bayberry Fen
        • 20. Relative shrub cover is not dominated by bayberry (Myrica pensylvanica).
      • 19. Relative cover for shrub layer is dominated by water-willow (Decodon verticillatus) or buttonbush (Cephalanthus occidentalis)
        • 23. Relative cover for shrub layer is dominated by water-willow (Decodon verticillatus), although buttonbush (Cephalanthus occidentalis) can be present with a lower percent cover.
          Water-willow (Decodon verticillatus) Shrub Wetland
        • 23. Relative cover for shrub layer is dominated by buttonbush (Cephalanthus occidentalis) although water-willow (Decodon verticillatus) can be present with a lower percent cover.
          Buttonbush Wetland

WOODLAND GROUP

  • 1. Relative cover of combined canopy and subcanopy for broadleaf deciduous species is greater than 75%. Red maple (Acer rubrum) is typically the dominant tree species.
    • 2. Relative cover of the shrub layer is less than 25%. Substrate is predominantly standing water between hummocks with a thick sedge herbaceous layer.
      Red maple – Sedge Palustrine Woodland
    • 2. Relative cover of the shrub layer is greater than 25%.
      • 3. Relative cover for shrub layer is dominated by red maple (Acer rubrum) and highbush blueberry (Vaccinium corymbosum). Other shrubs may include rosebay (Rhododendron maximum). Herbaceous layer has a strong Sphagnum moss (Sphagnum spp.) component.
        Red maple – Highbush Blueberry Palustrine Woodland
      • 3. Relative cover for shrub layer is dominated by red maple (Acer rubrum) and a combination of one or more of the following: willows (Salix spp.), spicebush (Lindera benzoin), winterberry (Ilex verticillata), smooth alder (Alnus serrulata), swamp rose (Rosa palustris), and buttonbush (Cepthanthus occidentalis). Sphagnum moss (Sphagnum spp.) is either absent or sparse in herbaceous layer.
        Red maple – Mixed Shrub Palustrine Woodland
  • 1. Relative cover for combined canopy and subcanopy for coniferous species is greater than 25%.
    • 4. Relative cover for combined canopy and subcanopy for coniferous species is greater than 25% but less than 75%.
      • 5. Relative cover for combined canopy and subcanopy is dominated or co-dominated by red spruce (Picea rubens) and/or American larch/tamarack (Larix laricina). Common hardwood species include yellow birch (Betula alleghaniensis), red maple (Acer rubrum), black ash (Fraxinus nigra), and occasionally sourgum (Nyssa sylvatica). The shrub layer can be dense and may include mountain holly (Ilex mucronata), highbush blueberry (Vaccinium corymbosum), winterberry (Ilex verticillata), swamp azalea (Rhododendron viscosum), and witherod (Viburnum cassinoides). Sphagnum moss (Sphagnum spp.) is usually present and substrate is composed of peat.
        Red Spruce – Mixed Hardwood Palustrine Woodland
      • 5. Relative cover for combined canopy and subcanopy is dominated by eastern hemlock (Tsuga canadensis). Associated hardwood species are yellow birch (Betula alleghaniensis), red maple (Acer rubrum), black ash (Fraxinus nigra), sourgum (Nyssa sylvatica), and gray birch (Betula populifolia). Rosebay (Rhododendron maximum) often forms a dense understory; other shrubs include highbush blueberry (Vaccinium corymbosum), winterberry (Ilex verticillata), swamp azalea (Rhododendron viscosum), mountain holly (Kalmia latifolia), maleberry (Lyonia ligustrina), leatherleaf (Chamaedaphne calyculata var. angustifolia), sheep laurel (Kalmia angustifolia), and witherod (Viburnum cassinoides).
        Hemlock – Mixed Hardwood Palustrine Woodland
    • 4. Relative cover for combined canopy and subcanopy for coniferous species is greater than 75%.
      • 6. Relative cover for combined canopy and subcanopy is dominated by black spruce (Picea mariana) and/or American larch/ tamarack (Larix laricina). Typically there is an extensive shrub layer usually dominated by leatherleaf (Chamaedaphne calyculata var. angustifolia), highbush blueberry (Vaccinium corymbosum), and/or rosebay (Rhododendron maximum). Sphagnum moss (Sphagnum spp.) is present. Substrate is composed of peat.
        Black Spruce - Tamarack Palustrine Woodland
      • 6. Relative cover for combined canopy and subcanopy is dominated by pitch pine (Pinus rigida). Leatherleaf (Chamaedaphne calyculata var. angustifolia) typically forms a dense shrub layer. Other shrubs include black chokeberry (Photinia melanocarpa), velvet-leaf blueberry (Vaccinium myrtilloides), sheep laurel (Kalmia angustifolia), Labrador tea (Rhododendron groenlandicum), rhodora (Rhododendron canadense), black huckleberry (Gaylussacia baccata), and scattered highbush blueberry (Vaccinium corymbosum). Sphagnum moss (Sphagnum spp.) is present.
        Pitch Pine – Leatherleaf Palustrine Woodland

FOREST GROUP

  • 1. Relative cover of coniferous species for combined canopy and subcanopy is greater than 25%.
    • 2. Relative cover of coniferous species for combined canopy and subcanopy is between 25% and 75%. The deciduous portion of the canopy may be a combination of yellow birch (Betula alleghaniensis), red maple (Acer rubrum), sourgum (Nyssa sylvatica), black ash (Fraxinus nigra), and/or gray birch (Betula populifolia).
      • 3. Canopy cover for coniferous species is dominated by red spruce (Picea rubens). Other conifers, such as eastern hemlock (Tsuga canadensis), eastern white pine (Pinus strobus), American larch/tamarack (Larix laricina), or balsam fir (Abies balsamea) may also be present at lower coverage.
        Red Spruce – Mixed Hardwood Palustrine Forest
      • 3. Canopy cover for coniferous species is dominated by eastern hemlock (Tsuga canadensis) and/or eastern white pine (Pinus strobus). Other conifers, such as red spruce (Picea rubens), American larch/tamarack (Larix laricina), and balsam fir (Abies balsamea) may also be present at lower coverage.
        Hemlock – Mixed Hardwood Palustrine Forest
    • 2. Relative cover of coniferous species for combined canopy and subcanopy is greater than 75%.
      • 4. Relative cover for combined canopy and subcanopy is greater for eastern hemlock (Tsuga canadensis) and/or eastern white pine (Pinus strobes) than spruce (Picea spp.) and American larch/tamarack (Larix laricina). Community typically has a hummock and pool micro-topography. Rosebay (Rhododendron maximum) typically forms a dense shrub layer.
        Hemlock Palustrine Forest
      • 4. Relative cover for combined canopy and subcanopy is greater for either red spruce (Picea rubens), black spruce (Picea mariana), or American larch/tamarack (Larix laricina) than relative cover for eastern hemlock (Tsuga canadensis) and/or eastern white pine (Pinus strobus).
        • 5. Relative cover for combined canopy and subcanopy is dominated or co-dominated by red spruce (Picea rubens) and/or American larch/tamarack (Larix laricina). The substrate is typically either shallow organic soils or mineral soils with substantial surface accumulation of organic material (histic epipedon).
          Red Spruce Palustrine Forest
        • 5. Relative cover for combined canopy and subcanopy is dominated by black spruce (Picea mariana) and/or American larch/tamarack (Larix laricina). The substrate consists of peat.
          Black Spruce – Tamarack Peatland Forest
  • 1. Relative cover of broadleaf deciduous species for combined canopy and subcanopy is greater than 75%.
    • 6. Relative cover for combined canopy and subcanopy is dominated by maple species (Acer spp.), elm species (Ulmus spp.), black ash (Fraxinus nigra), or sourgum (Nyssa sylvatica). While oak species (Quercus spp.) and green/red ash may be present, they are not dominant in the forest canopy.
      • 7. Relative cover for combined canopy and subcanopy is co-dominated by red maple (Acer rubrum) and some combination of one or more of the following: sweet-bay magnolia (Magnolia virginiana), sweetgum (Liquidambar styraciflua), sourgum (Nyssa sylvatica), ash species (Fraxinus spp.), and/or elm species (Ulmus spp.).
        • 8. Community is dominated by red maple (Acer rubrum) and a diverse mix of overstory hardwood species including sweet-bay magnolia (Magnolia virginiana) and sweetgum (Liquidambar styraciflua). Community is limited to the Coastal Plain and Piedmont within Pennsylvania.
          • 9. Community is found in permanently inundated wetlands and dominated by red maple; sweet-bay magnolia (Magnolia virginiana) and sweetgum (Liquidambar styraciflua) are also present; sweet pepperbush (Clethra alnifolia), fetter-bush (Leucothoe racemosa), winterberry (Ilex verticillata), smooth winterberry (Ilex laevigata), highbush blueberry (Vaccinium corymbosum), swamp azalea (Rhododendron viscosum), and possum-haw (Viburnum nudum). The herbaceous layer is often sparse. Community is limited to the Coastal Plain, restricted to low-lying areas of the Coastal Plain, with outliers occurring in the Piedmont and South Mountain sections Piedmont within Pennsylvania.
            Red Maple - Magnolia Palustrine Forest
          • 9. Community is found in depressions that are often flooded during winter and spring and is dominated by sweetgum (Liquidambar styraciflua). The herbaceous layer is variable; it is sparse where water stands for the longest time. Willow oak (Quercus phellos) and swamp chestnut oak (Quercus michauxii) are also present, in addition to other overstory hardwood species. Swamp dog-hobble (Leucothoe racemosa), sweet pepperbush (Clethra alnifolia), highbush blueberry (Vaccinium corymbosum), and southern arrow-wood (Viburnum dentatum) are characteristic shrubs. Community is limited to the Coastal Plain of Pennsylvania (Bucks County).
            Sweetgum – Willow Oak Coastal Plain Palustrine Forest
        • 8. Combined overstory a diverse mix of overstory hardwood species in addition to red maple (Acer rubrum) including sourgum (Nyssa sylvatica), ash species (Fraxinus spp.), yellow birch (Betula allegheniensis), and oaks (Quercus spp.). Forest canopy and subcanopy does not contain sweet-bay magnolia (Magnolia virginiana) or sweetgum (Liquidambar styraciflua). Community is not limited to the Coastal Plain and Piedmont within Pennsylvania.
          • 10. Relative cover for combined canopy and subcanopy is dominated by red maple (Acer rubrum) and/or blackgum/sourgum (Nyssa sylvatica). Other canopy trees include yellow birch (Betula allegheniensis), pin oak (Quercus palustris), and eastern hemlock (Tsuga canadensis). Soil and water pH is acidic.
            Red Maple – Black-gum Palustrine Forest
          • 10. Relative cover for combined canopy and subcanopy is dominated by red maple (Acer rubrum) and ash species (Fraxinus spp.). Other canopy trees include yellow birch (Betula allegheniensis) and pin oak (Quercus palustris). Sourgum (Nyssa sylvatica) may occasionally occur, but is never co-dominant.
            • 11. Community occurs in the back-swamp of the river floodplain, in abandoned oxbow-wetlands, and in depressions behind natural levees. Relative cover for combined canopy and subcanopy is dominated by red maple (Acer rubrum), red ash/green ash (Fraxinus pennsylvanica), American elm (Ulmus americana), slippery elm (Ulmus rubra), swamp white oak (Quercus bicolor), and pin oak (Quercus palustris).
              Elm - Ash - Maple Lakeplain Forest
            • 11. Community occurs primarily in headwater wetlands (not situated with the floodplain of major rivers). Species composition is influenced by calcareous groundwater; pH is circumneutral. Relative cover for combined canopy and subcanopy is dominated by red maple (Acer rubrum), black ash (Fraxinus nigra), red ash/green ash (Fraxinus pennsylvanica), American elm (Ulmus americana), or slippery elm (Ulmus rubra).
              • 12. Community is specific to Great Lakes Region; the canopy and subcanopy are composed of a wide variety of species including red maple (Acer rubrum), American elm (Ulmus americana), black ash (Fraxinus nigra), red ash/green ash (Fraxinus pennsylvanica), and/or pumpkin ash (Fraxinus profunda). Soils are not saturated throughout the year contributing to the high diversity of wetland and upland tree and shrub species.
                Red Maple – Black Ash Palustrine Forest
              • 12. Relative cover for combined canopy and subcanopy is dominated by red maple (Acer rubrum), black ash (Fraxinus nigra), swamp white oak (Quercus bicolor), and American elm (Ulmus americana). There is little to no sourgum (Nyssa sylvatica) present. Soils remain flooded and/or saturated throughout the year.
                Red Maple – Elm – Willow Floodplain Swamp
      • 7. Relative cover for combined canopy and subcanopy is dominated by silver maple (Acer saccharinum) or sugar maple (Acer saccharum). White ash (Fraxinus americana) may be a co-dominant canopy species.
        • 13. Relative cover for combined canopy and subcanopy is dominated by sugar maple (Acer saccharum). Other canopy species may include American basswood (Tilia americana), white ash (Fraxinus americana), silver maple (Acer saccharinum), black walnut (Juglans nigra), red ash/green ash (Fraxinus pennsylvanica), bitternut hickory (Carya cordiformis), black maple (Acer nigrum), and American beech (Fagus grandifolia). Community is usually located along mid- to high-floodplain terraces.
          Sugar Maple – Mixed Hardwood Floodplain Forest
        • 13. Relative cover for combined canopy and subcanopy is dominated by silver maple (Acer saccharinum) but other species can be present, such as sycamore (Platanus occidentalis), red maple (Acer rubrum), black willow (Salix nigra), river birch (Betula nigra), box-elder (Acer negundo), red ash/green ash (Fraxinus pennsylvanica), and elms (Ulmus americana and Ulmus rubra). Found along large rivers on well-developed floodplains and islands.
          Silver Maple Floodplain Forest
    • 6. Relative cover for combined canopy and subcanopy is dominated by red ash/green ash (Fraxinus pennsylvanica), oaks (Quercus spp.), sycamore (Platanus occidentalis), or bitternut hickory (Carya cordiformis).
      • 14. Relative cover for combined canopy and subcanopy is dominated by red ash/green ash (Fraxinus pennsylvanica) or oaks (Quercus spp.).
        • 15. Relative cover for combined canopy and subcanopy is dominated by red ash/green ash (Fraxinus pennsylvanica). Associate canopy species include black walnut (Juglans nigra) and sycamore (Platanus occidentalis). Community occurs on floodplains and terraces.
          Green Ash – Mixed Hardwood Palustrine Forest
        • 15. Relative cover for combined canopy and subcanopy is dominated by pin oak (Quercus palustris) and/or swamp white oak (Quercus bicolor). Associate canopy species include red ash/green ash (Fraxinus pennsylvanica), American elm (Ulmus americana), sourgum (Nyssa sylvatica), and black ash (Fraxinus nigra). Community typically occurs in backswamps.
          Oak - Mixed Hardwood Palustrine Forest
      • 14. Relative cover for combined canopy and subcanopy is dominated by sycamore (Platanus occidentalis) or bitternut hickory (Carya cordiformis). Community occurs on floodplains or terraces.
        • 16. Canopy is dominated by sycamore (Platanus occidentalis)
          • 17. Relative cover for combined canopy and subcanopy is dominated by sycamore (Platanus occidentalis); river birch (Betula nigra) is co-dominant or sub-dominant. Associate canopy species include sugar maple (Acer saccharum) (on smaller tributaries), silver maple (Acer saccharinum), and red/green ash (Fraxinus pennsylvanica).
            Sycamore – Mixed Hardwood Floodplain Forest
          • 17. Relative cover for combined canopy and subcanopy is dominated by sycamore (Platanus occidentalis); river birch (Betula nigra) is typically absent. Co-dominant or associate canopy species include sugar maple (Acer saccharum) (on smaller tributaries) and silver maple (Acer saccharinum).
            Sycamore Floodplain Forest
        • 16. Canopy is dominated by bitternut hickory (Carya cordiformis). Co-dominant or associate canopy species include northern red oak (Quercus rubra), butternut (Juglans cinerea), wild black cherry (Prunus serotina), sugar maple (Acer saccharum), American elm (Ulmus americana), white ash (Fraxinus americana), and silver maple (Acer saccharinum).
          Bitternut Hickory Floodplain Forest