PENNYSTONE • RESOURCES • NOTEBOOK

Northeastern Pennsylvania ecological communities

More than 130 specific ecosystems have been identified and cataloged for northeastern Pennsylvania. About half of these are habitable forests, woodlands, shrublands and open ground usually identified by specific dominant trees or other vegetation. The remainder are wetlands, including floodplains, bogs, swamps, fens and meadows, as well as a number of unusual habitats generally involving much bare rock.

The value to landscapers is two-fold: a starting point for developing landscape designs suitable for local soil conditions or as a means to consider naturally-occurring associations appropriate for developed models within larger contexts.

For the sake of convenience, the collection is divided into

Dry to mesic uplands, which can range from xeric to mesic but are almost always very well to excessively-drained.

Rich mesic uplands, which includes slopes and coves that tend to remain more moist and cool than dry uplands.

Floodplains of a wide variety can serve as models for various styles of rain gardens.

Wetlands include swamps, marshes, fens, meadows and bogs that can be modeled in home gardens

Water in either flowing or slowly circulating fashion (backyard ponds) can host many regional native hydromorphic species

Dry to mesic uplands

Yellow Birch-Red Oak Hardwood Forest: High elevations on rocky, cool, northeast to northwest-facing slopes with thin, sandy, sterile soils
Inland Pitch Pine - Oak Forest: Ridges and south facing slopes on droughty, sandy to gravelly, acidic glacial outwash or till
Dry Oak-Hickory Forest: High to midslopes, steps-in-slope and other dry-mesic sites, facing east to south, ranging from xeric to mesic
Allegheny Oak Forest: Dry upper slopes and terraces over sandstone or shale in unglaciated areas, dominated by several species of oaks.
Low-Elevation Mixed Oak Forest: Mountain valleys and lower mountain slope benches, typically on ancient alluvial fan deposits
Chestnut-Scarlet-Red Oak Forest: Dry middle and upper slopes, especially exposed convex slopes, with xeric to subxeric thin, sandy, stony soil
Chestnut-Red-Black Oak Forest: Dry ridgetops, high and steep side slopes and high, especially glaciated, plateau, on thin, sandy, stony soil.
Dry-Mesic Chestnut-Red Oak Forest: Protected rocky slopes with acidic soil, below exposed, xeric sites and above richer, more fertile coves
Oak - Hickory Sedge Lawn Forest: Dry, low-elevation ridgetops and upper slopes, south- or west-facing side slopes but most commonly southeast, with a lawn-like sedge floor.
Northern Hardwood Talus Slope Woodland: Talus slopes at low to mid-level elevations with soils from thin and patchy, nutrient-poor coarse-textured mineral materials
Birch Talus Woodland: Edges of large, barely weathered lichen-covered block fields and more weathered fields and slopes covered by bouldery colluvium
Limestone Chinquapin Oak Woodland: South to southwest-facing steep limestone and dolmitic slopes at elevations above 1,000 on shallow, stony, dry calcareous loams
Xeric Shale Woodland: Steep, west- to south-facing middle to upper slopes, typically with exposed mineral soils, loose stones and many shale outcrops
Red Oak - Heath Woodland: Dry low- to mid-elevation summits and south-facing upper slopes with prominent, exposed bedrock
Dry Oak-Hickory Woodland: Mid to upper level dry to mesic slopes, coves and ridgetops, predominantly on southern or eastern exposures.
Northern Hardwood - White Pine Forest: Well-drained, acidic, sandy or gravelly soil over glacial till, often on eskers and in narrow bands along lakeshores.
White Pine - Oak Forest: Flat to gently sloping mid and lower slopes, outwash plains or moraines and ravines with sandy, acidic, nutrient-poor soils
Hemlock - Sugar Maple Forest: North-facing, rocky, flat to moderately steep slopes; in unglaciated areas, sheltered ravines and along mountain streams
Hemlock - Black Cherry Forest: Rocky ravines or on moderately steep slopes, on stream terraces or occasionally on flats.
Hemlock - Beech - Oak Forest: Mesic to sub-mesic valley side slopes and broad, convex ridges with nutrient-poor, often stony sandy loams or loamy sand
Hemlock - Chestnut Oak Forest: Moderate to very steep sheltered slopes, usually midslopes, facing northeast to northwest
Acidic Shale Woodland: Unstable, steep shale slopes, often with areas of exposed bedrock on convex slopes, ridge spurs or clifftops, facing southeast to west
Pine - Oak Woodland: Convex, xeric, rocky and generally south to west facing slopes, crests, clifftops and ridge spurs
Red Pine Forest: Steep slopes, usually near summits, that face north to northwest in sandy, acidic soil.
White Pine - Hemlock Forest: Midslopes in dry to mesic, well-drained but nutrient-poor acidic soils
Eastern White Pine Forest: Moderately to steeply slopes or in sheltered ravines in well-drained soils
Mixed Pine - Hillside Blueberry Forest: Ridges, steep upper slopes, bluffs, knobs and cliff tops, usually facing southeast to southwest
Red Spruce Woodland: Acidic bedrock outcrops, talus or summits on the Allegheny Front on sparse, thin but very organic nutrient-poor soil
Mesic Pine Barrens: The Long Pond Barrens; relatively fine-textured, compact till, less permeable than the typical "pine barren" sands
Pitch Pine Rocky Summit: Dry rocky ridges and summits of low to moderate elevations, with coarse sands or gravels in pockets of the exposed bedrock
Scrub Oak Barrens: Sand plains, outwash plains, sand dunes and glacial till dominated by pitch pine and scrubby oaks
Appalachian Cliff White-cedar Woodland: North-facing, steep calcareous cliffs and uplands above the cliffs, usually over limestone or dolomite bedrock
Spruce - Fir Rocky Ridge: Acidic bedrock outcrops or summits on shallow, coarse, acidic sands in crevices or sheltered areas
Little Bluestem Outcrop Opening: Rock outcrops, flat summits, plateaus and southwest facing upper slopes, with thin, rocky, acidic sandy to gravelly soils
Calcareous Montane Cliff: Calcareous cliffs typically associated with dolomite or limestone on thin, calcareous, usually moist soils on ledges and in crevices
Acidic Boulderfield: Completely exposed, minimally weathered sandstone and quartzite boulder fields, throughout low and middle elevations
Shale Cliffs and Talus: Steep, unstable shale talus and cliffs, with shallow, very well-drained soils usually from shale and siltstone
Eastern Acidic Cliff: Oak-pine-hemlock forest regions on dry vertical exposures of resistant acidic bedrock, with little or no soil development
Dry Cliff Sparse Vegetation: Steep to vertical exposures of sandstone bedrock, usually on south and west-facing slopes; soil is coarse sand and sparse organic matter
Ridgetop Scrub Oak Barrens: Open or sparsely wooded high-elevation ridges, hilltops and outcrops or rocky slopes on well-drained, extremely thin and shallow soils
Blueberry Shrubland: Acidic rock outcrops or summits, ledges, and summits; sometimes in depressions on level outwash plains or valley floor frost pockets
Blueberry Granite Barrens: High-elevation glaciated rocky ridges, summits and outcrops on shallow, well-drained, dry, acidic, coarse sands

Rich mesic uplands

Sugar Maple-Ash Hardwood Forest: Ridgetops and slope hollows with slightly enriched soils, dominated by sugar maple and ash.
Sugar Maple-Beech Hardwood Forest: Middle of gentle to moderately steep slopes facing north to east, dominated by sugar maple, beech and yellow birch
Sugar Maple-Cherry Hardwood Forest: Flat to moderate mesic slopes usually facing north and at higher elevations on nutrient-rich soils.
Calcareous Talus Slope Forest: Loose rock or scree slopes over rich mesic but shallow, rocky to bouldery soils, usually facing north to east.
Sugar Maple-Tuliptree Hardwood Forest: Lower slopes, slope bases and moderate to steep concave slopes facing northwest to east with deep, fertile soils
Sugar Maple - Basswood Forest: Concave slopes and enriched coves with nutrient-rich, mesic to wet mesic conditions, especially where colluvium collects
Ridge and Valley Calcareous Forest: Steep east- and north-facing, rocky-bottomed ephemeral and intermittent creeks, dominated by sugar maple and white ash
Sugar Maple - Chinkapin Oak Limestone Forest: Low hills and knobs in patches of dry to dry-mesic soils over calcareous substrates, including limestone glades.
Rich Boulderfield Forest: Steep slopes, usually along streams or rivers, covered with rocky colluvium, dominated by basswood and sugar maple.
Tuliptree - Beech - Maple Forest: Gentle to slightly steep low and midslopes, often on mesic toeslopes, in coves with near-surface groundwater
Oak - Red Maple Successional Forest: Northern and eastern-facing coves and midslopes, following severe disturbance, on deep, moist to well-drained loams
Red Oak - Northern Hardwood Forest: Glaciated midslopes and coves dominated by oaks with no dwarf-shrub ericads and few conifers
Rich Red Oak - Sugar Maple Forest: Somewhat fertile, red oak-dominated coves, midslopes and well-drained flats with sandy to stony loams
American Basswood - White Ash Woodland: Mountainous areas with soils limited to pockets within calcareous to circumneutral talus
Oak - Pine Successional Forest: Former agricultural land and old fields no longer intensively mowed, plowed or managed

Floodplains

Green Ash - Maple Bottomland Forest: Poor drainage backswamps, sloughs, abandoned oxbows, and depressions of large-stream and river floodplains
Maple - Ash - Elm Swamp Forest: Depressions on level areas and backswamps, seasonally wet but which can dry in summer
Box-elder Floodplain Forest: Along larger rivers and on sandbars; sometimes on higher floodplain terraces used for agriculture
Silver Maple Floodplain Levee Forest: Terraces, levees and point bars of medium to large, moderate gradient, high energy rivers with substantial sedimentation
Silver Maple Forest: Banks and first bottoms of major rivers with brief annually or less often inundation; rich silt loamy soils
Silver Maple - American Elm Forest: Smaller rivers, dominated by silver maple and elm, often saturated but freely drained
Silver Maple Floodplain Forest: Large, regularly but briefly innundated floodplains, especially at the downstream ends of islands and on high terraces
Silver Maple Floodplain Bottom Forest: Inner floodplains of medium to large rivers and lake plains on poorly drained soils subjected to frequent spring flooding
Hardwood Floodplain Forest: Low to mid alluvial terraces of major rivers and tributaries dominated by sugar maple and white ash
High-gradient Hardwood Floodplain Forest: Level to gently-sloping natural levees, terraces and low ridges bordering rivers or high-gradient streams.
River Birch Low Floodplain Forest: Levees, gravel bars, braided channels of frequent flooding along large and moderately large rivers
Bitternut Hickory - Black Cherry Forest: Mid to high floodplain terraces of mid- to large-sized rivers; formerly cleared and settled areas in the floodplain
Green Ash - Mixed Hardwood Floodplain Forest: Behind levees and on low terraces flooded annually for brief periods, usually less than one week annually
Rich Floodplain Forest: Higher elevations of floodplains, low terraces and floodplain berms of rivers that drain areas of nutrient-rich substrates
Sycamore - Green Ash Floodplain Forest: Mid-successional, mid-terraces of major rivers and high-energy tributaries, dominated by sycamore and green ash
Swamp White Oak Floodplain Forest: Lower plains and terraces of major rivers, on silty and somewhat enriched soils dominated by swamp white oak.
Pin Oak Small River Floodplain Forest: High terraces above major rivers, low terraces of smaller streams and broad, flat areas with braided drainage
Sycamore - River Birch Scour Woodland: Frequently inundated, coarse-textured or fine-textured depositional bars and islands with sandy to silty soils
Water-willow Rocky Bar and Shore: Shoals or bars of rivers and rocky streams that are subjected to frequent, high-energy inundation.
Fall-line Riverwash Bedrock Prairie: Along high-gradient sections of major rivers, especially gorges and along the areas of waterfalls and rapids
Cobble Scour Rivershore: Cobble, gravel, and sand bars or banks along medium to high energy river channels and, less often, on exposed lakeshores
Twisted Sedge Rocky Bar and Shore: Frequently flooded rock, gravel and sand bars along active channel shelves of high-gradient streams and small rivers in valleys and gorges
Hairy-fruit Sedge Wetland: Small, narrow, linear patches on floodplain edges, deposition bars and islands with no tree canopy
Riverside Prairie Grassland: Sandy point bars and linear sand and gravel deposits along semi-stable river shores subject to periodic inundation
Loosestrife - Dogbane Rivershore: Riverbanks, low terraces, island heads, bars and spits in cobbles and sand, with thin deposits of silt, muck or organic matter
Riverside Rock Outcrop: Open, scoured exposures of bedrock of major rivers, usually along river narrows; some pockets of alluvial silt
Floodplain Alder Thicket: Along rivers and streams on rocky shoals and gravel bars, marsh edges, and small upland depressions
Willow River-Bar Shrubland: Along moderate- to high-energy rivers subjected to both flooding and ice scour on cobble substrates within a sand or gravel matrix

Wetlands: swamps, fens, meadows, seeps, bogs

Red Maple Seepage Swamp: Upland and floodplain edge depressions, impounded drainages, poorly drained areas of small creeks
Red Maple - Blackgum Basin Swamp: Saturated to seasonally wet perched basins of small watersheds within upland forests
Acidic Seepage Swamp: Groundwater-saturated flats and low slopes along streams throughout the Ridge and Valley province
Forested Acidic Seep: Forested seeps, hillsides, streamheads, floodplain edges, and poorly drained depressions
Northern Red Maple Swamp: Small upland depressions, impounded or braided drainages, wetland borders or as part of a larger wetland complex
Rich Red Maple - Black Ash Swamp: Saturated muck or peat along streams or at headwaters where red maple and tamarack dominate
Red Maple - Black Ash Swamp: Poorly drained depressions or seepage zones or as portions of larger swamps with muck but little peat.
Pin Oak - Swamp White Oak Forest: Hardwood basin areas with shallow, perched water tables that tend to be dry in late summer and early fall.
Red Maple Wooded Marsh: Poorly drained depressions influenced by groundwater, especially in basin settings near streams and lakes.
Conifer - Red Maple Acidic Swamp: Basins or low flats with hummock and hollow microtopography with organic muck or shallow peat over clay loam
Hemlock-Maple Swamp-Bog Complex: Occasionally-flooded streams, in poorly-drained bottomlands, and along stream headwaters draining visible groundwater discharge
Hemlock - Yellow Birch Seepage Swamp: High-elevation valleys or slope hollows, in stream headwaters and groundwater-saturated flats along larger streams
Spruce Swamp Forest - Bog Complex: Generally flat areas of higher elevations, in poorly drained bottomlands of small streams and isolated ridgetop depressions.
Appalachian Spruce - Fir Swamp: Flats and basins on the glaciated plateau, as well as across the northern Appalachians
Red Spruce Woodland Swamp: Headwater basins of steams at higher elevations; considered rare and imperiled
Hemlock - Hardwood Swamp: Glaciated areas in poorly drained basins over bedrock or compacted till, south of spruce-fir regions
Hemlock - Great Laurel Swamp: Upland bedrock depressions, low slopes and around small streams, lakes and drainages
Pitch Pine Bog: Shallow, poorly drained depressions or basins with a deep accumulation of peat, sometimes near upland sandplain pine barrens
Golden Saxifrage Forested Seep: Small herbaceous seepage areas with scattered cover of highly variable forb cover, depending on local soils and cover
Leafy Forb Marsh: Along pond and lake shores, impoundments and quiet riverbanks with mucky soils in shallow to deep standing water
Skunk Cabbage Seep: Low-lying streamheads, borders of small streams where groundwater emerges, and the drainages of lower slopes
Ironweed - Marsh Fern Seep: Patches of one to six acres within forests at sites where calcareous groundwater discharge is found throughout the growing season
Pasture Fen: Where calcareous groundwater discharges to the surface, generally along the toeslope of ridges and in association with limestone or calcareous siltstone
Northern Bayberry Fen: Spring-fed calcareous sites with thin peat over mineral soils heavily coated with calcium carbonate deposits
Bluejoint Wet Meadow: Small stream floodplains, poorly drained depressions, levees, lakeshores and beaver meadows
Mixed Graminoid Meadow: Flats, floodplains of small streams, lakeshores and beaver meadows; wet in spring, dry in summer
Prairie Sedge - Tussock Sedge Fen: Saturated peat-accumulating, sedge-dominated glaciated areas near calcareous seeps and springs
Tussock Sedge Meadow: Seasonally flooded basins or on edges of lakes or streams edges, throughout the northeastern United States.
Three-way Sedge Basin Marsh: Headwater basins, near beaver ponds, shallow basins, swales, bog mat moats, or in areas where seepage is impounded by natural levees
Calcareous Bulrush Marsh: Standing water on lakeshores in limestone regions; scattered, rare and dominated by hardstem bulrush
Medium Fen: Peaty lakeshores in acidic waters t fed by weakly-nutritious surface water or seepage from surrounding uplands
Bulrush Deepwater Marsh: Quiet water areas near the shores of ponds, lakes, rivers and larger streams, but also in ditches and flooded basins
Wool Grass Marsh: Seasonally flooded marshes or the emergent zones of upland depression ponds, saturated to ponded in winter and drying completely in summer.
Eastern Cattail Marsh: Permanently flooded basins, usually as a segment of a larger wetland group and typically with lakes, ponds or slow streams
Intermediate Graminoid Fen: Along lakes and other depressions covered by a thick layer of peat and dense mats of sedges
Gray Alder Swamp: Edges of beaver meadows in stream floodplains, upland forests, and swales associated with small peatland streams
Smooth Alder Swamp: Near red maple swamps, upland marsh borders or in acidic of upland marsh borders, or in acidic sediment at slope bases
Buttonbush Shrub Swamp: Backwater sloughs or oxbow ponds, wet swales in floodplains, pond and lake borders, and small, isolated upland depressions
Calcareous Shrub Fen: Where groundwater seeps to the surface, such as the base of gravelly moraines, on gently to moderately sloping surfaces
Blueberry Wetland Thicket: Seasonally flooded zones of larger wetlands, margins of coastal plain ponds, closed sandplain basins and small open basins
Steeplebush Successional Wet Meadow: Low areas of old fields or pastures, headwater basins and beaver-impacted areas, saturated for part of the growing season, dry the rest.
Highbush Blueberry Bog Thicket: Border thicket around more open dwarf heath shrub peatlands or in isolated basins, lacking inlet or outlet streams, in glaciated regions
Leatherleaf Bog: Peat-accumulating basins that offer little to support life, generally in areas of black spruce bogs that become too wet to support black spruce
Silky Willow Shrub Swamp: Topographic basins, floodplain backswamps, along slow-moving streams and on lake shores

Water: rivers, lakes, ponds, marshes

Duckweed Pond: Permanently, periodically or seasonally flooded wetlands in shallow to deeper standing water
Water-lily Aquatic Wetland: Shallow water depressions, oxbow ponds, backwater sloughs of river floodplains, ponds, small lakes and slow-moving streams
Riverweed Rocky Bar and Shore: Rocky surfaces in stream and river beds of mature drainage systems, especially where the floodplain is narrow
Open Water Marsh: Sheltered bays of lakes and streams relatively undisturbed by wave action, dominated by submergent or emergent plants

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