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Ecological site F148XY029PA

Moist, High Base-Saturation, Riparian Zone, Ecotonal Meadow-Shrub-Forest

Last updated: 3/10/2021
Accessed: 08/29/2026

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General information

Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

MLRA notes

Major Land Resource Area (MLRA): 148X–Northern Piedmont

This ecological site description was developed for the Northern Piedmont Major Land Resource Area (MLRA) 148 as defined by USDA Handbook 296. The Northern Piedmont is a major land resource area within the North Atlantic Slope Diversified Farming Land Resource Region (LRR). The Northern Piedmont MLRA extends from northeast to southwest for approximately 325 miles (525 km) and is approximately 100 miles (160 km) inland from the Atlantic coast. It is approximately 12,800 square miles (33,150 square kilometers) and is spread across portions of Virginia (30%), Maryland (21%), Pennsylvania (38%), Delaware (1%), and New Jersey (10%) (USDA-NRCS, 2006).

Most of the land in the Northern Piedmont is privately owned. Farming is highly diversified, and common crops include truck crops, horticultural trees, fruits, soybeans, grain, forage, poultry, beef, and dairy cattle. The Washington D.C. to Boston “megalopolis” development corridor dominates an important extent of the land (1/3 or more), and urban areas are encroaching on farmland and woodlands across the region. The remaining forests commonly are on steep slopes, rocky soils, or riparian zones where both agriculture and development are difficult (USDA-NRCS, 2006; Woods et al., 1999).

The extent to which indigenous peoples altered the precolonial vegetation of the region is unclear. Some evidence indicates that savannah-like woodlands and grasslands occupied portions of the Northern Piedmont at the onset of European settlement. The evidence suggests that the indigenous communities may have used fire as a land-management tool.

The vegetation communities across the Northeast began experiencing significant influences from European settlers in approximately 1650. These influences included widespread agricultural land clearing, forest harvesting, charcoal production, and the introduction of exotic species, insects, and disease vectors, especially chestnut blight. The loss of American chestnut has been significant across the entire eastern United States. This loss, however, may be less ecologically significant in portions of the Northern Piedmont. For example, little evidence exists to suggest that American chestnut was an important constituent of forests growing on soils derived from carbonate parent materials (Virginia DCR, 2016).

The acreage of forest across the Northern Piedmont reached its low in the mid-nineteenth century. The acreage then increased as agriculture expanded to the Midwest and industrialization concentrated populations into urban areas. The Northern Piedmont includes some of the most productive farmland in the East, so farm abandonment was not as common in MLRA 148 as in other parts of the Northeast. Regionally, widespread farm abandonment led to a trend of reforestation. The recovering forest appears to have included all native forest species, with the notable exception of American chestnut. The proportions, however, were different (maples are notably more common) and more homogenous. The current forest vegetation communities in the Northern Piedmont likely do not show the same level of sorting by local climatic and edaphic factors as influenced precolonial forest composition. Urban sprawl is once again removing land from vegetation cover, but, in the Northern Piedmont, this impact is on both forested and agricultural lands. Additionally, the continued and increasing introduction of exotic and invasive plants, insects, and disease vectors remains a profound threat to forest stability (Thompson et al., 2013).

In the Northern Piedmont, Pinus virginiana (Virginia pine) and Liriodendron tulipifera (tulip-poplar) are common early-successional forest pioneers, especially on uplands. The composition of the more mature forest stands tends to vary with soils, topography, and succession. Dry, nutrient poor sites tend to be dominated by an oak-heath forest community. More mesic sites on soils that have a more basic chemistry tend to support an oak-hickory forest cover. Quercus alba (white oak) is a relative generalist, and it is a common component in all types of upland oak forest of the Northern Piedmont. Quercus rubra (northern red oak) and Quercus velutina (black oak) commonly join the overstory on mesic and submesic sites. Quercus montana (chestnut oak), Quercus coccinea (scarlet oak), and Quercus falcata (southern red oak) prefer drier sites. Quercus stellate (post oak) and Quercus marilandica var. marilandica (blackjack oak) tend to do well on the most drought-prone sites.

Carya (hickories) show a preference for sites that have a higher base saturation, so they are common in both the overstory and understory of the more basic oak-hickory types. Overall species richness tends to be higher on these higher base saturation sites as well. Common constituents include Carya ovata (shagbark hickory), Fraxinus americana (white ash), and Cercis canadensis var. canadensis (eastern redbud). Ericaceous (heather) shrubs tend to be absent on these alkaline sites, but herbaceous species richness tends to be high. Hickories are also common on intermediate oak-hickory sites. The understories, however, are more dominated by Cornus florida (flowering dogwood), Viburnum acerifolium (mapleleaf viburnum), and dry-mesophytic herbaceous generalists.

Most oak-heath forests support few hickories and have few herbaceous species in the understory. These forest communities tend to have an understory dominated by Acer rubrum (red maple), Nyssa sylvatica (blackgum), and deciduous ericad (plants that dislike alkaline soils) shrubs, such as Vaccinium pallidum (early lowbush blueberry), Gaylussacia baccata (black huckleberry), and other heathers (Virginia DCR, 2016).

In cool, moist ravines that have acidic soils, a mesic mixed hardwood forest of American beech (Fagus grandifolia), white oak, northern red oak, and tulip-poplar is common. This forest community is thought to be replacing upland oak-hickory forests in many areas where fire has been excluded for long periods or where oak recruitment has declined for other reasons (Zimmerman et al., 201). In cool, moist ravines that have more mafic or calcareous substrates, similar mesic mixed hardwood forests also commonly include Fraxinus americana (white ash), Carya cordiformis (bitternut hickory), Tilia americana (basswood), Quercus muehlenbergii (chinquapin oak), Acer saccharum (sugar maple), and dense, species-rich understories where overstory shade is not too extreme.

Riparian forests and flood-plain forests grow widely across the Northern Piedmont. Along larger rivers, these forests tend to be dominated by flood-tolerant trees, such as Acer saccharinum (silver maple), Platanus occidentalis (sycamore), Ulmus americana (American elm), Acer negundo (eastern boxelder), Celtis occidentalis (common hackberry), and Betula nigra (river birch). In high energy environments, these flood-plain forest types are commonly broken by flood-scoured deposition bars, outcrops, and early successional vegetation communities. Along stretches that do not flood as deeply, hydrophytic oaks—such as Quercus palustris (pin oak), Quercus bicolor (swamp white oak), Quercus phellos (willow oak), Quercus lyrata (overcup oak), and Quercus michauxii (swamp chestnut oak)—may dominate the overstory, and Carex (sedges) commonly form large, dense understory communities.

Some additional minor, small-patch forest types (such as eastern white pine-hardwood types and eastern hemlock-hardwood types) and some rock outcrop barrens are scattered across the Northern Piedmont in isolated areas. The eastern hemlock ecological communities are much more consistent with the MLRA concepts of the Northern Blue Ridge and the Ridge and Valley. In the Northern Piedmont, the eastern hemlock communities are thought to represent the last vestiges of a community that is migrating to cooler sites in response to global climate change over the past several thousand years (Virginia DCR, 2016).

Classification relationships

Several modern classification systems for vegetation are used across the United States. The Federal Geographic Data Committee suggests that the U.S. National Vegetation Classification (USNVC) should be the Federal standard. An analysis of the existing vegetation cover using the U.S. Geological Survey, Gap Analysis Program (2011) indicates that the natural vegetation areas in the Northern Piedmont MLRA are predominantly Appalachian-Northeastern Oak-Hardwood-Pine Forest and Woodland (USNVC Macrogroup, 502). A few additional USNVC macrogroups are also present. On a finer scale, USNVC Groups 15 and 650 dominate nearly all site types across the MLRA. This dominance supports the theory that extreme anthropogenic disturbances near the turn of the century significantly homogenized the forests of this region. At any specific field site, existing vegetation may not be a good indication of the best suited potential vegetation. Representative USNVC groups are listed for each ecological site. Groups have been identified by analyzing both existing vegetation cover indicated by GAP/Landfire (USGS, 2011) as well as the vegetation inventory data from the Natural Heritage programs.

The Northern Piedmont MLRA as defined in USDA Handbook 296 (USDA-NRCS, 2006) very nearly matches the Northern Piedmont Level III Ecoregion as defined by the U.S. Environmental Protection Agency. The U.S. EPA Level III Ecoregions have also been further subdivided into Level IV Ecoregions. Within MLRA 148 Northern Piedmont, the EPA Level IV Ecoregions are:
• Triassic Lowlands
• Trap Rock (Diabase) and Conglomerate Uplands
• Piedmont Uplands
• Piedmont Limestone/Dolomite Lowlands
• Passaic Basin Freshwater Wetlands

These Level IV Ecoregions explain much of the ecological variation across the MLRA and have been used extensively to assist with defining the Ecological Sites.

Triassic Lowlands
The Triassic Lowlands are dominated by Alfisols derived from Triassic sedimentary rocks. These soils are relatively fertile and typically have a moderate to high level of base saturation in the subsoil. The landscape is comparatively flat and is not highly dissected. The region is characterized by wide undulating ridges; broad, nearly level valleys; and limited local relief. Streams and wetlands are important in the Triassic Lowlands. Wetlands are becoming rarer, especially adjacent to the urban sprawl of megalopolis (Woods et al., 1999).

Trap Rock and Conglomerate Uplands
The Trap Rock and Conglomerate Uplands are often also referred to as the Diabase and Conglomerate Uplands. Trap rock is a common term for diabase and other mafic igneous intrusions. This landscape was developed during the Triassic and Jurassic eras as diabase sills, and dikes intruded the sedimentary rocks of the surrounding Triassic Lowlands. The landscape is characterized by wooded, stony hills and steep ridges underlain by a mixture of highly resistant rocks rising relatively sharply above the Triassic Lowlands. The soils are mostly thin (shallow), fine-textured, clayey, non-acidic Alfisols that are hard to till and best suited to forest or pasture. The forests of these uplands are somewhat distinct from those of the rest of the Northern Piedmont because acid loving plants are largely absent, especially on soils derived from diabase. Woodlands continue to be comparatively common in this landscape, especially on steep slopes and in areas where surface rocks and boulders are common (Woods et al., 1999).

Piedmont Uplands
The Piedmont Uplands are dominated by deep Ultisols and Inceptisols that developed from crystalline bedrock. The Piedmont Uplands have substantially higher relief than the Triassic Lowlands. The region is characterized by rounded hills, low ridges, and narrow valleys. The eastern edge of the piedmont creates a relatively abrupt “fall line” as the landscape drops down to the adjacent sediments of the coastal plain. The drop includes high stream gradient, waterfalls, and exposed bedrock. Due to the mixed source materials, the mineralogy of the soils of the Piedmont Uplands varies. The typical piedmont upland is comprised of soils derived from felsic crystalline rocks, but some piedmont soils are derived from more mafic rocks. Some locations have chrome soils derived from ultra-mafic serpentine, which is low in calcium but high in magnesium, chromium, and nickel. Variations in geologic parent material commonly create soils that support corresponding variations in vegetation communities. Serpentine soils support unique “barrens” vegetation communities of oak and pine, greenbrier, and prairie grass (Woods et al., 1999).

Piedmont Limestone/Dolomite Lowlands
The Piedmont Limestone/Dolomite Lowlands are comprised of Hapludalfs derived from carbonate bedrock. Hapludalfs are soils that have a horizon of clay accumulation with a significant decrease in clay content within a depth of 150 centimeters. The soils are potentially highly fertile. The carbonate bedrock weathered to create a landscape of undulating terrain that includes karst features, such as sinkholes, caves, and underground streams. Nearly all the forests on these carbonate lowlands have been replaced by agriculture. This is one of the most productive farming regions of the eastern United States. The predominant natural vegetation community is oak forests dominated by red oak and white oak, but the flora on these basic carbonate soils is distinct from the heath communities on the acidic and less fertile soils of the surrounding areas (Woods et al., 1999).

The Northern Piedmont (MLRA 148) is within the U.S. Forest Service Eastern Broadleaf Forest Province (biome). The Eastern Broadleaf Forest Province is mesophytic and dominated by the drought-resistant oak-hickory forest association, which includes Quercus alba (white oak), Quercus rubra (northern red oak), Quercus falcate (southern red oak), Quercus velutina (black oak), Carya cordiformis (bitternut hickory), and Carya ovata (shagbark hickory). It has well-developed understories of Cornus spp. (dogwood), Sassafras albidum (sassafras), and Carpinus spp. and Ostrya spp. (hornbeam). Ulmus americana (American elm), Liriodendron tulipifera (tuliptree), and Liquidambar styraciflua (sweetgum) are common on somewhat richer sites (Bailey, 1995).

As defined by USDA (USDA-NRCS, 2006), MLRA 148, the Northern Piedmont, coincides well with the U.S. Forest Service ecological section the Northern Appalachian Piedmont. The northwest corner of MLRA 148 also includes a small portion of the Lower New England ecological section (the Reading Prong), where some glacial landforms intermingle with typical piedmont landforms. The main cover types in Northern Appalachian Piedmont Section, as defined by the U.S. Forest Service, are oak-hickory and loblolly-shortleaf pine (McNab et al., 2007).

U.S. Forest Service ecological subsections that coincide with MLRA 148 include the Reading Prong Subsection of the Lower New England Section, the Gettysburg Piedmont Lowland, the Northern Piedmont, the Piedmont Upland, and the Triassic Basins. Note the high level of coincidence between the U.S. Forest Service ecological subsections and the EPA level IV ecoregions.

Ecological site concept

This ecological site is highly variable, occupies a variety of landscape positions, and supports a variety of vegetation communities. Riparian zones often possess parent materials from a variety of sources due to the mixing effects of fluvial processes. However, these sites tend to be dominated by circumneautral soils derived from mafic parent materials.

Many vegetation communities on these ecologically mesic riparian sites are also on other riparian ecological sites. The mesic, riparian-zone sites all represent locations where the soils are not hydric and are on flood plains, low terraces, low-order valley bottoms, and adjacent side slopes and are surrounding (but not in) springs, seeps, and stream heads. As such, mesic, riparian-zone sites are ecotonal by definition. They reflect the transition from truly upland to truly hydric lowland. Mesic, riparian-zone sites tend to be in positions that are slightly above the water level where frequency and duration of flooding are lower or in positions where the soils are coarse grained and sufficiently deep to dry out relatively quickly following a flood (Zimmerman et al., 2012).

Distribution of flood energy directly affects particle-size distribution during deposition. The resulting variations in soil texture can significantly affect vegetation communities. The ecologically mesic, riparian-zone sites can occur on soils of any texture, but, when in or adjacent to a perennial stream or river, will often occur on sandy soils or exposed bedrock. The sand can be deep or can be a thin deposit over gravel or cobbles. The mesic sites either do not accumulate fibrous organic material or they accumulate less than the more hydric riparian sites. Accumulation is affected by the persistence of saturation and the strength of flood energy (Zimmerman et al., 2012).

Vegetation communities in the riparian zone are highly influenced by hydrography, especially duration of soil saturation and exposure to flood energy. In very general terms, vegetation communities that are closer to a body of water are likely to be flooded more often and for longer periods of time than those communities that are farther away. Flowing water (streams and rivers) exerts higher energy disturbance than standing water (lakes and ponds). The larger the stream, upstream watershed, valley-or-channel-width restriction, and stream gradient, the greater the increase in frequency, duration, and energy of disturbance of flooding. Regional climate across the Northern Piedmont makes flood-entrained ice (with its unique scouring potential) a notable possibility during winter and spring flooding (Zimmerman et al., 2012).

Due to the ecotonal nature of mesic riparian sites, the vegetation communities are also transitional. Vegetation communities transition from upland communities to wetland communities. As such, these ecological sites display many potential location-specific phases (Zimmerman et al., 2012).

This ecological site corresponds with:

US National Vegetation Classification (USGS, 2011)
• Dominant: Oak-Hickory (USNVC Group 15)
• Bald-cypress–Water Tupelo Floodplain Forest (USNVC Group 33)
• Swamp Chestnut Oak-Laurel Oak-Sweetgum Floodplain Forest (USNVC Group 34)
• Silver Maple-Sugarberry-Sweetgum Floodplain Forest (USNVC Group 673)

Table 1. Dominant plant species

Tree	Not specified
Shrub	Not specified
Herbaceous	Not specified

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Physiographic features

The Northern Piedmont (MLRA 148) is surrounded by the Northern Appalachian Ridges and Valleys (MLRA 147), the Northern Blue Ridge (MLRA 130A), the Northern Coastal Plain (MLRA 149A), the Southern Piedmont (MLRA 136), and the New England and eastern New York Uplands (MLRA 144A). From the northwest to southeast, the landscape transitions between three dominant physiographic regions: mountains, piedmont, and coastal plain. This transition is much narrower across the Northern Piedmont than across the Southern Piedmont. The Northern Piedmont has a cooler climate than the Southern Piedmont (MLRA 136). The Northern Piedmont also has taller intrusive dikes and sills of resistant rocks which, along with differential erosion, have created sharp ridges. These ridges have longer and steeper slopes in 148, and are more common in MLRA 148 than in MLRA 136.

The dominant feature (besides climate) that distinguishes the Northern Piedmont from the ecoregions further to the north is that the Northern Piedmont has never been glaciated (with the minor exception of the Reading Prong area). The glaciated regions to the north are dominated by mineral soils that have not yet differentiated into distinct horizons (Entisols). The Northern Piedmont transitions to the west and northwest into the Northern Blue Ridge (MLRA 130A) and Northern Appalachian Ridges and Valleys (MLRA 147), which have increased mountainous topography, and to the east into the flat sedimentary landscapes of the Northern Coastal Plain (USDA-NRCS, 2006).

The Northern Piedmont is a transitional region between the flat coastal plain to the southeast and the mountains to the northwest. It is comprised of low, rounded hills and open valleys. Along the northeast edge of the MLRA, the low areas are below sea level. Some areas have elevations as low as 165 feet below sea level (-51 meters). In the central and western areas of the Northern Piedmont, the highest elevations rise to 2,125 feet (649 meters). These highest elevations are not typical and are formed by diabase intrusions. Crested elevations typically range from about 325 feet (99 meters) on limestone to 1,300 feet (396 meters) on more resistant crystalline rock (Woods et al., 1999).

As a transition zone between distinctly different ecoregions, the Northern Piedmont is a landscape of diverse landforms. Across the MLRA, less than 5 percent of the landscape is covered by depositional landforms and 75 to 95 percent of the landscape is distinctly erosional.

Landform Percent of MLRA
Flat* 3%
Summit 2%
Ridge 15%
Shoulder 2%
Spur 17%
Slope 30%
Hollow 11%
Footslope 3%
Valley 14%
Depression 2%
* Flat landforms include surface water features

The geology of the Northern Piedmont is highly complex and variable. The eastern boundary of the MLRA marks the “fall line;” that is, the transition from the crystalline bedrock of the interior to the Coastal Plain sediments of the east. The eastern third of the MLRA is dominated by metamorphic gabbro, gneiss, serpentine, marble, slate, and schist as well as intrusive granite. The central portions of the Northern Piedmont are comprised of Triassic period sandstone, shale, and conglomerate basin deposits dissected by Jurassic diabase and basalt dikes and sills. The western portion of the Northern Piedmont includes large areas underlain by limestone (USDA-NRCS, 2006; USGS, 2011).

Areas of metamorphic and igneous bedrock are typically covered by a mantle of soil that formed in residuum (Ultisols) and saprolite that weathered in place. Areas of mixed sedimentary rock are typically derived from sediments deposited in basins created by Mesozoic (Triassic and Jurassic) rift-valley drop blocks. The Culpepper Basin is a typical Triassic basin in the Virginia range of the Northern Piedmont.

Ultisols are the dominant soil order in the Northern Piedmont, but Alfisols and Inceptisols are also widespread and locally dominant. Entisols occur locally in high-energy fluvial and colluvial settings (USDA-NRCS, 2006; Virginia DCR, 2016). Ultisols, Alfisols, Inceptisols, and Entisols are 4 of the 12 orders in the USDA system of soil classification. Ultisols have low base status and a clay-enriched subsoil. Alfisols are naturally fertile and have high base saturation and a clay-enriched subsoil horizon. Inceptisols have a weak, but noticeable degree of horizon development. Entisols have little or no horizon development. Details regarding soil classification are available from the USDA (USDA-NRCS, 2018).

The Ultisols in the Northern Piedmont are commonly leached, acidic, and infertile (deficient in calcium, magnesium, potassium, and total base saturation) and have well-developed, red or yellowish red, clay subsurface horizons. The Alfisols tend to be deep, well-developed, and moderately to highly fertile, especially those soils that have a high base saturation and that formed in material weathered from calcareous or mafic bedrock. The Inceptisols vary highly in texture and composition. In the Northern Piedmont, they are most common on the erosive slopes of the inner (western) Piedmont foothills.

Udalfs, Udults, Udepts, and fragipans are common across the North Atlantic Slope Diversified Farming Region (of which the Northern Piedmont is a sub-division). In low, wet depressions, Aquults and Aquepts are common. Udepts and Fluvents are typically on flood plains and in riparian areas. The soil temperature regime is predominantly mesic. The soil moisture regime is predominantly udic, and the dominant soil mineralogy across the region is micaceous, kaolinitic (Ultisols), or mixed (Alfisols and Inceptisols) (USDA-NRCS, 2006).

Figure 1. EPA Level IV ecoregions across MLRA 148.

Figure 2. Geologic parent material across MLRA 148.

Figure 3. Ecological Site soil moisture and landform groups across MLRA 148.

Figure 4. The Moist Basic Riparian Zone Ecological Site footprint.

Figure 5. PRISM 30 year mean annual precipitation across MLRA 148.

Figure 6. PRISM 30 year mean annual temperature across MLRA 148.

Table 2. Representative physiographic features

Climatic features

The climate of the Northern Piedmont is humid, temperate, and continental with variable weather patterns across the region. The four seasons are distinctly different. Winters are cold and moist. Occasionally, the jet stream dips south over the Northern Piedmont during the winter, resulting in brief periods of bitter cold. Both spring and fall tend to be cool and wet. Summers are hot, humid, and have short periods of drought that can be interrupted by intense thunderstorms (USDA-NRCS, 2006; Woods et al., 1999).

The average annual precipitation for the Northern Piedmont is 40 to 55 inches (100 to 135 cm). The average is higher in the northern areas of the region and on the eastern edge nearer the Atlantic. Most of the precipitation for this region is received during the spring and fall. Precipitation is moderate in the winter and is mainly from snow. Occasionally, hurricanes and “nor’easters” produce extreme-precipitation events, but the typical maximum-precipitation events occur as high intensity, convective thunderstorms in spring and early summer. Local droughts of 10 to 14 days are common in the region during summer (USDA-NRCS, 2006).

The northern part of the MLRA tends to be on the cooler and wetter end of the range. The southern part tends to be warmer and drier. The average annual temperature in the Northern Piedmont ranges from 48 to 58 degrees Fahrenheit (9 to 14 degrees C). The hottest average temperatures are in the southern parts of the region. The freeze-free period averages 205 days across the region and ranges from 170 to 240 days (USDA-NRCS, 2006).

Precipitation (mm)
Month Min Mean Max
Jan 61 80 97
Feb 59 70 89
March 82 96 113
April 79 93 112
May 96 108 127
June 77 101 125
July 85 111 138
Aug 70 91 116
Sept 95 111 154
Oct 76 95 122
Nov 81 92 111
Dec 68 88 107
Annual1,009 1,136 1,337

Precipitation (inches)
Month Min Mean Max
Jan 2.4 3.1 3.8
Feb 2.3 2.8 3.5
March 3.2 3.8 4.4
April 3.1 3.7 4.4
May 3.8 4.3 5.0
June 3.0 4.0 4.9
July 3.3 4.4 5.4
Aug 2.7 3.6 4.6
Sept 3.7 4.4 6.1
Oct 3.0 3.7 4.8
Nov 3.2 3.6 4.4
Dec 2.7 3.5 4.2
Annual 39.7 44.7 52.6

Temperature (Celsius)
Month Min Mean Max
Jan -5.3 -0.3 4.6
Feb -4.2 1.2 6.5
March -0.4 5.5 11.4
April 5.0 11.4 17.9
May 10.2 16.6 23.0
June 15.4 21.6 27.7
July 18.0 24.0 29.9
Aug 17.1 23.1 29.0
Sept 12.9 19.1 25.2
Oct 6.5 12.8 19.0
Nov 1.7 7.4 13.0
Dec -3.0 1.9 6.7
Annual 6.2 12.0 20.5

Temperature (Fahrenheit)
Month Min Mean Max
Jan 23 31 40
Feb 25 34 44
March 31 42 52
April 41 53 64
May 50 62 73
June 60 71 82
July 64 75 86
Aug 63 74 84
Sept 55 66 77
Oct 44 55 66
Nov 35 45 55
Dec 27 35 44
Annual 43 54 69

Table 3 Representative climatic features

Frost-free period (actual range)
Freeze-free period (actual range)
Precipitation total (actual range)	40-50 in
Frost-free period (average)
Freeze-free period (average)	210 days
Precipitation total (average)	50 in

Bar

Line

Figure 7. Monthly average minimum and maximum temperature

Influencing water features

Fresh surface water is abundant in this region, and groundwater springs are common. Abundant precipitation, numerous perennial streams, and good aquifers provide ample supplies of fresh water. Surface water quality is marginal but generally sufficient for all uses across the region. It can be good for public supply if treated properly. Many streams and rivers have been degraded by sedimentation, mining waste, and municipal and industrial discharges. 
 
Major rivers in the Northern Piedmont include the Delaware River, which separates Pennsylvania and Delaware from New Jersey; the Susquehanna River; and the Potomac River, which separates Washington D.C. and Maryland from Virginia. The Susquehanna River valley is unique in this ecoregion because the river is large and incised with local relief as high as 590 feet (180 m) along the valley margins. Gorges flowing into the Susquehanna contain high-gradient streams and waterfalls, including Otter Creek, Tucquan Glen, Wildcat Run, Counselman Run, Kelly Run, Ferncliff Run, and Oakland Run. The Northern Piedmont also includes several National Wild and Scenic Rivers, including the Schuylkill, Octoraro, Patuxent, Monocacy, and Rappahannock Rivers and Goose Creek and Deer Creek (USDA-NRCS, 2006; Woods et al., 1999). 
 
For the purposes of these ecological site descriptions, the riparian zone is the area that is adjacent to surface waters and that should be managed specifically for its potential to deliver water-quality-related riparian services, including soil stabilization, filtration, and infiltration of overland flow. Many of the hydric soils in the Northern Piedmont are along the riparian zones of rivers and streams. Some are in small, isolated wetlands. Although small, isolated wetlands are not always in a classic riparian setting, the distinction is largely irrelevant for general considerations related to vegetation management. The vegetation-management solutions that are used in classic riparian settings would also filter and infiltrate overland flow in small, isolated wetlands. Additionally, many small isolated wetlands are in the slack regions of larger riparian systems. Those in isolated upland depressions commonly consist of a local seep outlet in a zone where ground water intermittently surfaces before eventually accumulating as first-order surface waters. Such areas are intermittent riparian zones, and represent hydrologic ecotones by there very nature. An important aspect of ecological site development for riparian zones is the exceptional difficulty in defining exactly where a riparian zone begins. 
 
Even more difficult is classifying the energy environment within a riparian zone. It is nearly impossible to tie that variation to field sites at the spatial and temporal scale used by the USDA Soil Survey Geographic Database (SSURGO). The probability, intensity, frequency, and duration of fluvial energy varies in both space and time across a riparian system, and these variables have critical impacts on the soils and vegetation communities. The size of the adjacent creek, stream, or river, the size of the watershed, the position in the watershed, the position on the flood plain, upstream land use, and local hydrodynamics are all variables affecting soil. Some of these variables are not directly represented in SSURGO. Also, SSURGO map units do not always have perfect fidelity with these variables. In the timeframes and spatial scales in which hight-energy fluvial events occur, it may not be possible to remap SSURGO with sufficient frequency at the series level. Mapping might best capture the concept, but it does not always capture a potential soil or ecological state at any specific location. Delivering user-friendly, site-specific management recommendations in an ESD based on such mapping is therefore difficult and is impossible without real time field verification by a conservation planner.

Ecological dynamics

Four vegetation community structures are common in the mesic riparian zones of the Northern Piedmont: forests, brush thickets, meadows, and zones of sparse vegetation and exposed substrate. In some areas, the vegetation community might progress through a classic successional sequence from exposed substrate to grass to brush to forest following a stand replacement disturbance. Under these circumstances, and in the absence of additional disturbance, succession typically proceeds quickly to forest. However, riparian zone brush thickets, meadows, and zones of sparse vegetation commonly exist as disturbance-driven climax communities. The fluvial processes of erosion, deposition, and aggradation are highly dynamic; consequently, so are the vegetation structure and composition within a riparian zone. Vegetation community dynamics are especially intense on the mesic, riparian-zone sites where flood energy is relatively high and on sites that represent the ecotonal transition from upland to riparian. Across the riparian zone, location-specific vegetation communities largely reflect location specific disturbance history (Zimmerman et al., 2012).

State and transition model

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Ecosystem states

1. S1: Reference State - moist riparian forest

2. S2: moist riparian brush thicket

3. S3: moist riparian meadow

4. S4: moist riparian sparse vegetation

State 1 submodel, plant communities

1.1. Mesic Basic Upland Rich Forest Phase

1.2. Mesic Upland Generalist Forest Phase

1.3. Mesic Generalist Floodplain Forest Phase

1.4. Vernal Pools

State 1
S1: Reference State - moist riparian forest

The forested reference state for these mesic riparian zone sites occurs in at least 3 general phases including:
- Mesic Basic Upland Rich Forest Phase
- Mesic Upland Generalist Forest Phase
- Mesic Generalist Floodplain Forest Phase
These phases are described in detail in the State 1 sub-model section of this document.

Community 1.1
Mesic Basic Upland Rich Forest Phase

The impacts of acidity or base saturation on vegetation communities is higher on drier sites, but the basic rich forest phase can still occur on the riparian transition from upland to lowland.

The Northern Piedmont MLRA as a whole is dominated by the Oak-Hickory group (USNVC 2.01, 2016), but this does not mean that representative oaks or hickories are on all sites. The cover-type expressions of this ecological site group vary. Quercus rubra (northern red oak) and Quercus velutina (black oak) tend to be more important in the drier areas within this ecological site group. Quercus alba (white oak) is ubiquitous. Although the species composition is very mixed, the most consistent tree species are Acer rubrum (red maple) and Liriodendron tulipifera (tuliptree). Fagus grandifolia (American beech) is common and, where present, is commonly codominant. Other commonly associated trees include Carya ovata (shagbark hickory), Carya cordiformis (bitternut hickory), Carya tomentosa (mockernut hickory), Nyssa sylvatica (blackgum), Betula lenta (sweet birch), Betula alleghaniensis (yellow birch), Fraxinus Americana (white ash), Cercis canadensis (eastern redbud), Prunus serotina (wild black cherry), Tilia americana (basswood), Quercus muehlenbergii (chinquapin oak), and Acer saccharum (sugar maple). Tsuga canadensis (eastern hemlock) grows on some sites. It may be either a minor or dominant component (Virginia DCR, 2016; USNVC 2.01, 2016; USGS, 2011; Zimmerman et al., 2012).

In many places, the herb and shrub flora are dense and well developed with a wide variety of species. Rhododendron maximum (rosebay), Hamamelis virginiana (witchhazel), and Lindera benzoin (spicebush) are abundant on many sites. A dense understory of Asimina triloba (common pawpaw) is common. Other common species include viburnum spp., Carpinus caroliniana (hornbeam), Cornus florida (flowering dogwood), Ostrya virginiana (hophornbeam), and Staphylea trifolia (bladdernut). Magnolia tripetala (umbrella magnolia) is not uncommon (Zimmerman et al., 2012).

Areas that are under a hardwood canopy and are not overbrowsed can have a dense cover of shrubs or herbs. Herb and shrub cover tend to be less dense under hemlock cover. Some herbaceous species are more sensitive to nutrient conditions. Nutrient-loving herbs that are representative of this ecological site include Caulophyllum thalictroides (blue cohosh), Actaea racemosa (black bugbane), Chrysogonum virginianum (green and gold), Salvia urticifolia (nettleleaf sage), Triosteum angustifolium (lesser horse-gentian), Ruellia purshiana (Pursh’s wild petunia), Muhlenbergia sobolifera (rocky muhly), Asarum canadense (wild ginger), Adiantum pedatum (maidenhair fern), Podophyllum peltatum (mayapple), Tiarella cordifolia (foamflower), Jeffersonia diphylla (twinleaf), Dicentra cucullaria (Dutchman’s breeches), Erythronium americanum (trout lily), Uvularia perfoliata (perfoliate bellwort), Botrychium virginianum (rattlesnake fern), Dicentra canadensis (squirrel corn), Allium tricoccum (wild leek), Claytonia virginica (springbeauty), Sanguinaria canadensis (bloodroot), Anemone quinquefolia (wood anemone), Cimicifuga racemosa (black snakeroot), Geranium maculatum (wood geranium), Hepatica nobilis (liverleaf), Arisaema triphyllum (Jack in the pulpit), Mitella diphylla (bishop's-cap), Cardamine concatenata (cutleaf toothwort), Maianthemum canadense (Canada mayflower), Corydalis flavula (yellow fumewort), Asplenium spp. (spleenworts), and Polystichum acrostichoides (Christmas fern). Mesophytic forest generalist herbs include Hylodesmum nudiflorum (nakedflower ticktrefoil), Polygonatum biflorum (Solomon’s-seal), Smilacina racemosa (false Solomon's-seal), Dryopteris marginalis (evergreen wood fern), Aster divaricatus (white wood aster), and Maianthemum racemosum (eastern Solomon’s-plume) (Virginia DCR, 2016; Zimmerman et al., 2012; USNVC 2.01, 2016).

Plants that are diagnostic of basic oak-hickory forests in the Piedmont include Carya ovata (shagbark hickory), Fraxinus americana (white ash), Cercis canadensis (eastern redbud), Actaea racemosa (black bugbane), Chrysogonum virginianum (green and gold), Salvia urticifolia (nettleleaf sage), Triosteum angustifolium (lesser horse-gentian), Ruellia purshiana (Pursh’s wild petunia), and Muhlenbergia sobolifera (rocky muhly) (Virginia DCR, 2016).

This phase of this ecological site corresponds with:

Pennsylvania Communities
(Zimmerman et al., 2012)
• Tuliptree-beech-maple forest
• Sugar maple-basswood forest
• Rich hemlock-mesic hardwoods forest
• Hemlock-tuliptree-birch forest
• Red maple (terrestrial) forest

Representative species are listed below in alphabetical order.

The database section for grasses / herbs only allows 20 species and the list for this phase is longer than 20. Hence the herbaceous species list is provided here:
Herbaceous Species
• Actaea racemosa (black bugbane)
• Adiantum pedatum (maidenhair fern)
• Allium tricoccum (wild leek)
• Anemone quinquefolia (wood anemone)
• Arisaema triphyllum (Jack in the pulpit)
• Asarum canadense (wild ginger)
• Asplenium spp. (spleenworts)
• Aster divaricatus (white wood aster)
• Botrychium virginianum (rattlesnake fern)
• Cardamine concatenata (cutleaf toothwort)
• Caulophyllum thalictroides (blue cohosh)
• Chrysogonum virginianum (green and gold)
• Cimicifuga racemosa (black snakeroot)
• Claytonia virginica (springbeauty)
• Corydalis flavula (yellow fumewort)
• Dicentra canadensis (squirrel corn)
• Dicentra cucullaria (dutchman’s breeches)
• Dryopteris marginalis (evergreen wood fern)
• Erythronium americanum (trout lily)
• Geranium maculatum (wood geranium)
• Hepatica nobilis (liverleaf)
• Hylodesmum nudiflorum (nakedflower ticktrefoil)
• Jeffersonia diphylla (twinleaf)
• Maianthemum canadense (Canada mayflower)
• Maianthemum racemosum (eastern Solomon’s-plume)
• Mitella diphylla (bishop's-cap)
• Muhlenbergia sobolifera (rocky muhly)
• Podophyllum peltatum (mayapple)
• Polygonatum biflorum (Solomon’s-seal)
• Polystichum acrostichoides (Christmas fern)
• Ruellia purshiana (Pursh’s wild petunia)
• Salvia urticifolia (nettleleaf sage)
• Sanguinaria canadensis (bloodroot)
• Smilacina racemosa (false Solomon's-seal)
• Tiarella cordifolia (foamflower)
• Triosteum angustifolium (lesser horse-gentian)
• Uvularia perfoliata (perfoliate bellwort)

Dominant plant species

red maple (Acer rubrum), tree
sugar maple (Acer saccharum), tree
yellow birch (Betula alleghaniensis), tree
sweet birch (Betula lenta), tree
bitternut hickory (Carya cordiformis), tree
mockernut hickory (Carya tomentosa), tree
shagbark hickory (Carya ovata), tree
eastern redbud (Cercis canadensis), tree
American beech (Fagus grandifolia), tree
white ash (Fraxinus americana), tree
tuliptree (Liriodendron tulipifera), tree
blackgum (Nyssa sylvatica), tree
black cherry (Prunus serotina), tree
white oak (Quercus alba), tree
chinquapin oak (Quercus muehlenbergii), tree
northern red oak (Quercus rubra), tree
black oak (Quercus velutina), tree
American basswood (Tilia americana), tree
eastern hemlock (Tsuga canadensis), tree
pawpaw (Asimina triloba), shrub
American hornbeam (Carpinus caroliniana), shrub
flowering dogwood (Cornus florida), shrub
American witchhazel (Hamamelis virginiana), shrub
northern spicebush (Lindera benzoin), shrub
umbrella-tree (Magnolia tripetala), shrub
hophornbeam (Ostrya virginiana), shrub
great laurel (Rhododendron maximum), shrub
American bladdernut (Staphylea trifolia), shrub
mapleleaf viburnum (Viburnum acerifolium), shrub
southern arrowwood (Viburnum dentatum), shrub
southern arrowwood (Viburnum recognitum), shrub

Community 1.2
Mesic Upland Generalist Forest Phase

The Mesic Generalist communities of the Northern Piedmont have a very broad ecological amplitude. The Northern Piedmont MLRA as a whole is dominated by the Oak-Hickory group (USNVC 2.01, 2016), but this does not mean that representative oaks or hickories are on all sites. The cover-type expressions of this ecological site group vary. On this site, in this phase, Quercus rubra (northern red oak) is typically present and is commonly dominant or codominant. On these sites, it is most commonly in association with Acer rubrum (red maple), Quercus velutina (black oak), Quercus alba (white oak), Carya tomentosa (mockernut hickory), Carya ovata (shagbark hickory), Betula lenta (sweet birch), Betula alleghaniensis (yellow birch), Fraxinus americana (white ash), Fagus grandifolia (American beech), Prunus serotina (wild black cherry), and/or Liriodendron tulipifera (tuliptree). Some areas have a significant conifer component in which Tsuga canadensis (eastern hemlock), Pinus strobus (eastern white pine), or both contribute the most. Conifers may be scattered, locally abundant, and dominant in the subcanopy. In some areas, eastern white pine forms a relict supracanopy or grows in large gaps in the former canopy (USNVC 2.01, 2016; Zimmerman et al., 2012; Virginia DCR, 2016).

Shrubs include Viburnum acerifolium (mapleleaf viburnum), Viburnum recognitum (northern arrowwood), Viburnum dentatum (southern arrowwood), Rhododendron periclymenoides (pinxter-flower), Amelanchier laevis (smooth serviceberry), Amelanchier arborea (shadbush), Carpinus caroliniana (hornbeam), Ostrya virginiana (hophornbeam), Hamamelis virginiana (witchhazel), Corpus florida (flowering dogwood), and Lindera benzoin (spicebush). Kalmia latifolia (mountain laurel) and Gaylussacia baccata (black huckleberry) are also present in some areas (Zimmerman et al., 2012).

The herbaceous layer is highly variable. Representative species include Smilacina racemosa (false Solomon's-seal), Polygonatum biflorum (Solomon's seal), Gaultheria procumbens (teaberry), Maianthemum canadense (Canada mayflower), Podophyllum peltatum (mayapple), Uvularia sessilifolia (wild-oats), Chimaphila maculata (pipissewa), Medeola virginiana (Indian cucumber-root), Caulophyllum thalictroides (blue cohosh), and, on richer sites, Dryopteris (wood ferns) and Dennstaedtia punctilobula (hayscented fern) (Zimmerman et al., 2012).

This phase of this ecological site corresponds with:

Pennsylvania Communities
(Zimmerman et al., 2012)
• Hemlock (white pine)-red oak-mixed hardwood forest
• Red oak-mixed hardwood forest
• Red maple (terrestrial) forest

Representative species are listed alphabetically.

Dominant plant species

red maple (Acer rubrum), tree
yellow birch (Betula alleghaniensis), tree
sweet birch (Betula lenta), tree
shagbark hickory (Carya ovata), tree
mockernut hickory (Carya tomentosa), tree
American beech (Fagus grandifolia), tree
white ash (Fraxinus americana), tree
tuliptree (Liriodendron tulipifera), tree
eastern white pine (Pinus strobus), tree
black cherry (Prunus serotina), tree
white oak (Quercus alba), tree
northern red oak (Quercus rubra), tree
black oak (Quercus velutina), tree
eastern hemlock (Tsuga canadensis), tree
common serviceberry (Amelanchier arborea), shrub
Allegheny serviceberry (Amelanchier laevis), shrub
American hornbeam (Carpinus caroliniana), shrub
flowering dogwood (Cornus florida), shrub
black huckleberry (Gaylussacia baccata), shrub
American witchhazel (Hamamelis virginiana), shrub
mountain laurel (Kalmia latifolia), shrub
northern spicebush (Lindera benzoin), shrub
hophornbeam (Ostrya virginiana), shrub
pink azalea (Rhododendron periclymenoides), shrub
mapleleaf viburnum (Viburnum acerifolium), shrub
southern arrowwood (Viburnum dentatum), shrub
southern arrowwood (Viburnum recognitum), shrub
blue cohosh (Caulophyllum thalictroides), grass
striped prince's pine (Chimaphila maculata), grass
eastern hayscented fern (Dennstaedtia punctilobula), grass
woodfern (Dryopteris), grass
eastern teaberry (Gaultheria procumbens), grass
Canada mayflower (Maianthemum canadense), grass
Indian cucumber (Medeola virginiana), grass
mayapple (Podophyllum peltatum), grass
smooth Solomon's seal (Polygonatum biflorum), grass
sessileleaf bellwort (Uvularia sessilifolia), grass

Community 1.3
Mesic Generalist Floodplain Forest Phase

This phase of this ecological site corresponds with:

International Vegetation Classification Associations
(Zimmerman et al., 2012)
• New River Sycamore-Ash Floodplain Forest (CEGL006458)
• Piedmont/Central Appalachian Rich Floodplain Forest (CEGL004073)
• Sycamore-Silver Maple Calcareous Floodplain Forest (CEGL007334)
• Silver Maple Floodplain Bottom Forest (Sensitive Fern Type) (CEGL006176)
• Silver Maple Floodplain Levee Forest (CEGL006147)
• Silver Maple-Elm Forest (CEGL002586)
• Piedmont/Central Appalachian Rich Floodplain Forest (CEGL004073)
• River Birch Low Floodplain Forest (CEGL006184)
• Red Maple-Blackgum Basin Swamp (CEGL006014)

Pennsylvania Communities
(Zimmerman et al., 2012)
• Red maple–black-gum palustrine forest
• Silver maple floodplain forest
• Sycamore-mixed hardwood floodplain forest
• Sycamore floodplain forest

Representative species are listed below alphabetically.

The database section for grasses / herbs only allows 20 species and the list for this phase is longer than 20. Hence the herbaceous species list is provided here:
• Arisaema dracontium (green dragon)
• Arisaema triphyllum (Jack in the pulpit)
• Bidens frondosa (beggartick)
• Boehmeria cylindrica (false nettle)
• Carex crinita var. crinita (short hair sedge)
• Carex intumescens (sedge)
• Carex lurida (sedge)
• Cinna arundinacea (wood reedgrass)
• Elymus riparius (riverbank wildrye)
• Glyceria septentrionalis (floating mannagrass)
• Impatiens capensis (jewelweed)
• Laportea canadensis (woodnettle)
• Leersia oryzoides (rice cutgrass)
• Lilium superbum (Turk's-cap lily)
• Lycopus uniflorus (bugleweed)
• Matteuccia struthiopteris (ostrich fern)
• Onoclea sensibilis (sensitive fern)
• Osmunda cinnamomea (cinnamon fern)
• Persicaria punctata (dotted smartweed)
• Persicaria virginiana (jumpseed)
• Pilea pumila (clearweed)
• Solidago spp. (goldenrods)
• Symplocarpus foetidus (skunk cabbage)
• Teucrium canadense (wild germander)
• Thelypteris palustris (marsh fern)
• Urtica dioica (stinging nettle)
• Verbesina alternifolia (wingstem)
• Viola sororia (common blue violet)

Vines
• Toxicodendron radicans (poison ivy)
• Vitis riparia (riverbank grape)

Dominant plant species

boxelder (Acer negundo), tree
red maple (Acer rubrum), tree
silver maple (Acer saccharinum), tree
yellow birch (Betula alleghaniensis), tree
river birch (Betula nigra), tree
common hackberry (Celtis occidentalis), tree
green ash (Fraxinus pennsylvanica), tree
black walnut (Juglans nigra), tree
blackgum (Nyssa sylvatica), tree
eastern white pine (Pinus strobus), tree
American sycamore (Platanus occidentalis), tree
white oak (Quercus alba), tree
swamp white oak (Quercus bicolor), tree
pin oak (Quercus palustris), tree
northern red oak (Quercus rubra), tree
black oak (Quercus velutina), tree
black willow (Salix nigra), tree
eastern hemlock (Tsuga canadensis), tree
American elm (Ulmus americana), tree
slippery elm (Ulmus rubra), tree
alder (Alnus), shrub
silky dogwood (Cornus amomum), shrub
flowering dogwood (Cornus florida), shrub
gray dogwood (Cornus racemosa), shrub
common winterberry (Ilex verticillata), shrub
northern spicebush (Lindera benzoin), shrub
common ninebark (Physocarpus opulifolius), shrub
highbush blueberry (Vaccinium corymbosum), shrub
mapleleaf viburnum (Viburnum acerifolium), shrub
southern arrowwood (Viburnum recognitum), shrub

Community 1.4
Vernal Pools

This phase is a micro-site in the matrix of mesic uplands. The vernal poos site occupies areas of depressions and deeper pools that are seasonally inundated but typically dry completely over the summer (Zimmerman et al., 2012).

This phase of this ecological site corresponds with:

International Vegetation Classification Associations
(Zimmerman et al., 2012)
Eastern Woodland Vernal Pool Sparse Vegetation (CEGL006453)

Species composition lists below are sorted alphabetically.

Dominant plant species

red maple (Acer rubrum), tree
blackgum (Nyssa sylvatica), tree
swamp white oak (Quercus bicolor), tree
pin oak (Quercus palustris), tree
common buttonbush (Cephalanthus occidentalis), shrub
common winterberry (Ilex verticillata), shrub
highbush blueberry (Vaccinium corymbosum), shrub
southern arrowwood (Viburnum recognitum), shrub
devil's beggartick (Bidens frondosa), grass
smallspike false nettle (Boehmeria cylindrica), grass
fringed sedge (Carex crinita), grass
greater bladder sedge (Carex intumescens), grass
shallow sedge (Carex lurida), grass
floating mannagrass (Glyceria septentrionalis), grass
northern bugleweed (Lycopus uniflorus), grass
dotted smartweed (Polygonum punctatum), grass
Canadian clearweed (Pilea pumila), grass
eastern marsh fern (Thelypteris palustris), grass
sphagnum (Sphagnum), grass

State 2
S2: moist riparian brush thicket

The brush thicket state is condition dominated by brush and young trees. This phase of this ecological site corresponds with:

International Vegetation Classification Associations
(Zimmerman et al., 2012)
• Allegheny Floodplain Alder Thicket (CEGL006251)
• Piedmont/Central Appalachian Sycamore-River Birch Scour Woodland (CEGL003896)

Pennsylvania Communities
(Zimmerman et al., 2012)
• Alder-dogwood floodplain thicket
• Mixed hardwood floodplain thicket

Representative species are listed below alphabetically.

The database section for grasses / herbs only allows 20 species and the list for this phase is longer than 20. Hence the herbaceous species list is provided here:
• Andropogon gerardii (big bluestem)
• Apocynum cannabinum (Indian hemp)
• Bidens spp. (beggartick)
• Boehmeria cylindrica (false nettle)
• Carex intumescens (sedge)
• Carex torta (twisted sedge)
• Dichanthelium clandestinum (deertongue grass)
• Elymus virginicus (Virginia wildrye)
• Eupatorium perfoliatum (boneset)
• Eutrochium fistulosum (Joe pye weed)
• Eutrochium maculatum (spotted Joe pye weed)
• Galium aparine (cleavers)
• Helenium autumnale (common sneezeweed)
• Hypericum pyramidatum (great St. Johnswort)
• Leersia virginica (cutgrass)
• Muhlenbergia spp. (muhly)
• Oxalis stricta (common yellow woodsorrel)
• Phalaris arundinacea (reed canarygrass)
• Pilea pumila (clearweed)
• Solidago gigantea (smooth goldenrod)
• Sorghastrum nutans (Indiangrass)
• Spartina pectinata (freshwater cordgrass)
• Teucrium canadense (wild germander)
• Thalictrum pubescens (tall meadow-rue)
• Verbesina alternifolia (wingstem)
• Viola spp. (violets)

Vines
• Calystegia sepium (hedge bindweed)
• Clematis virginiana (virgin's-bower)
• Vitis riparia (riverbank grape)
• Vitis spp. (grape)

Resilience management. Common Exotic Species • Fallopia japonica (Japanese knotweed) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=GLHE2" target="_blank" title="Open in plants.usda.gov">Glechoma hederacea</a> (Gill-over-the-ground) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=MIVI" target="_blank" title="Open in plants.usda.gov">Microstegium vimineum</a> (Japanese stiltgrass) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=ROMU" target="_blank" title="Open in plants.usda.gov">Rosa multiflora</a> (multiflora rose)

Dominant plant species

boxelder (Acer negundo), shrub
silver maple (Acer saccharinum), shrub
speckled alder (Alnus incana ssp. rugosa), shrub
hazel alder (Alnus serrulata), shrub
common buttonbush (Cephalanthus occidentalis), shrub
silky dogwood (Cornus amomum), shrub
redosier dogwood (Cornus sericea), shrub
common ninebark (Physocarpus opulifolius), shrub
American sycamore (Platanus occidentalis), shrub
eastern cottonwood (Populus deltoides), shrub
grayleaf red raspberry (Rubus idaeus ssp. strigosus), shrub
Missouri River willow (Salix eriocephala), shrub
narrowleaf willow (Salix exigua), shrub
black willow (Salix nigra), shrub
silky willow (Salix sericea), shrub
steeplebush (Spiraea tomentosa), shrub
American elm (Ulmus americana), shrub
southern arrowwood (Viburnum recognitum), shrub

State 3
S3: moist riparian meadow

The meadow state is dominated by grasses and herbs with only sparse woody vegetation (if any). This phase of this ecological site corresponds with:

International Vegetation Classification Associations
(Zimmerman et al., 2012)
• Big Bluestem-Switchgrass-Tall Blue Wild Indigo Herbaceous Vegetation (CEGL006283)
• Sandcherry/Big Bluestem-Yellow Indian-grass Herbaceous Vegetation (CEGL006518)
• Piedmont/Central Appalachian Riverbank Tall Herbaceous Vegetation (CEGL006480)
• Polygonum cuspidatum Temporarily Flooded Herbaceous Vegetation (CEGL008472)
• Reed Canary-grass Wet Meadow (CEGL006044)
• Rocky Bar and Shore (Twisted Sedge Type) (CEGL004103)

Pennsylvania Communities
(Zimmerman et al., 2012)
• Big bluestem-Indian grass floodplain grassland
• Floodplain meadow
• Japanese knotweed floodplain thicket
• Reed canarygrass floodplain grassland
• Twisted sedge (Carex Torta) stream margin

Representative species are listed below alphabetically.

The database section for grasses / herbs only allows 20 species and the list for this phase is longer than 20. Hence the herbaceous species list is provided here:
• Agrostis perennans (autumn bent)
• Agrostis stolonifera var. palustris (carpet bentgrass)
• Andropogon gerardii (big bluestem)
• Apocynum androsaemifolium (pink dogbane)
• Apocynum cannabinum (Indian hemp)
• Baptisia australis (blue false-indigo)
• Bidens spp. (beggartick)
• Boehmeria cylindrica (false nettle)
• Calamagrostis canadensis var. canadensis (Canada bluejoint)
• Carex stricta (tussock sedge)
• Carex torta (twisted sedge)
• Carex trichocarpa (sedge)
• Coreopsis tripteris (tall tickseed)
• Cyperus spp. (nutsedges)
• Dichanthelium clandestinum (deertongue grass)
• Doellingeria umbellata (flat-topped white aster)
• Elymus riparius (riverbank wildrye)
• Epilobium coloratum (purpleleaf willowherb)
• Equisetum arvense (field horsetail)
• Eupatorium perfoliatum (boneset)
• Euphorbia corollata (flowering spurge)
• Euthamia graminifolia (grass-leaved goldenrod)
• Eutrochium fistulosum (Joe pye weed)
• Eutrochium maculatum (spotted Joe pye weed)
• Helenium autumnale (common sneezeweed)
• Heliopsis helianthoides (oxeye)
• Hydrocotyle americana (marsh pennywort)
• Hypericum ellipticum (pale St. Johnswort)
• Impatiens capensis (jewelweed)
• Leersia oryzoides (rice cutgrass)
• Leersia virginica (cutgrass)
• Lobelia cardinalis (cardinalflower)
• Lobelia siphilitica (great blue lobelia)
• Lycopus uniflorus (bugleweed)
• Mentha arvensis (field mint)
• Muhlenbergia spp. (muhly)
• Onoclea sensibilis (sensitive fern)
• Oxalis stricta (common yellow woodsorrel)
• Panicum virgatum (switchgrass)
• Persicaria hydropiper (water-pepper)
• Persicaria hydropiperoides (mild water-pepper)
• Persicaria maculosa (ladysthumb)
• Persicaria pensylvanica (smartweed)
• Persicaria punctata (dotted smartweed)
• Persicaria sagittata (tearthumb)
• Phalaris arundinacea (reed canarygrass)
• Scirpus polyphyllus (bulrush)
• Solidago canadensis (Canada goldenrod)
• Solidago gigantea (smooth goldenrod)
• Solidago rugosa (wrinkleleaf goldenrod)
• Sorghastrum nutans (Indiangrass)
• Spartina pectinata (freshwater cordgrass)
• Symphyotrichum lateriflorum (calico aster)
• Triadenum virginicum (marsh St. Johnswort)
• Verbena hastata (blue vervain)
• Verbesina alternifolia (wingstem)
• Viola spp. (violets)

Vines
• Calystegia sepium (hedge bindweed)
• Clematis virginiana (virgin's-bower)
• Parthenocissus quinquefolia (Virginia creeper)
• Toxicodendron radicans (poison ivy)
• Vitis labrusca (fox grape)
• Vitis riparia (riverbank grape)

Resilience management. Common Exotic Species • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=ALPE4" target="_blank" title="Open in plants.usda.gov">Alliaria petiolata</a> (garlic mustard) • Fallopia japonica (Japanese knotweed) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=LOMO2" target="_blank" title="Open in plants.usda.gov">Lonicera morrowii</a> (Morrow's honeysuckle) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=MIVI" target="_blank" title="Open in plants.usda.gov">Microstegium vimineum</a> (Japanese stiltgrass) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=PHAR3" target="_blank" title="Open in plants.usda.gov">Phalaris arundinacea</a> (reed canarygrass) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=ROMU" target="_blank" title="Open in plants.usda.gov">Rosa multiflora</a> (multiflora rose)

Dominant plant species

silver maple (Acer saccharinum), shrub
river birch (Betula nigra), shrub
silky dogwood (Cornus amomum), shrub
northern spicebush (Lindera benzoin), shrub
common ninebark (Physocarpus opulifolius), shrub
American sycamore (Platanus occidentalis), shrub
Missouri River willow (Salix eriocephala), shrub
black willow (Salix nigra), shrub
white meadowsweet (Spiraea alba), shrub
steeplebush (Spiraea tomentosa), shrub

State 4
S4: moist riparian sparse vegetation

This phase of this ecological site corresponds with:

International Vegetation Classification Associations
(Zimmerman et al., 2012)
• Northern Riverside Rock Outcrop (CEGL006284)
• Barbara’s buttons Riverscour Prairie (CEGL006598)
• Northeastern Temperate Cobble Scour Rivershore (CEGL006536)

Pennsylvania Communities
(Zimmerman et al., 2012)
• Floodplain scour community
• Periodically exposed shoreline community

Representative species are listed below alphabetically

The database section for grasses / herbs only allows 20 species and the list for this phase is longer than 20. Hence the herbaceous species list is provided here:
Herbs
• Acalypha rhomboidea (three-seeded mercury)
• Agrostis perennans (autumn bent)
• Amorpha fruticosa (false indigo)
• Andropogon gerardii (big bluestem)
• Apocynum cannabinum (Indian hemp)
• Aristida purpurascens (arrowfeather)
• Boltonia asteroides (aster-like boltonia)
• Cyperus erythrorhizos (redroot flatsedge)
• Cyperus squarrosus (umbrella sedge)
• Cyperus strigosus (false nutsedge)
• Echinochloa muricata (barnyardgrass)
• Eleocharis acicularis (needle spikerush)
• Eleocharis erythropoda (spike-rush)
• Eleocharis obtusa (Wright's spikerush)
• Eleocharis palustris (creeping spikerush)
• Eleocharis tenuis var. pseudoptera (slender spikerush)
• Equisetum arvense (field horsetail)
• Eragrostis frankii (lovegrass)
• Eragrostis hypnoides (creeping lovegrass)
• Eupatorium perfoliatum (boneset)
• Eupatorium serotinum (late eupatorium)
• Euphorbia maculata (spotted spurge)
• Eutrochium spp. (Joe pye weed)
• Fimbristylis autumnalis (slender fimbry)
• Hibiscus laevis (halberdleaf rosemallow)
• Hydrocotyle americana (marsh pennywort)
• Hypericum densiflorum (bushy St. Johnswort)
• Hypericum ellipticum (pale St. Johnswort)
• Hypericum mutilum (dwarf St. Johnswort)
• Hypericum pyramidatum (great St. Johnswort)
• Juncus acuminatus (sharp-fruited rush)
• Juncus canadensis (Canada rush)
• Justicia americana (water-willow)
• Lindernia dubia (false pimpernel)
• Lobelia cardinalis (cardinalflower)
• Ludwigia palustris (marsh-purslane)
• Lycopus uniflorus (bugleweed)
• Lysimachia terrestris (swamp-candles)
• Lysimachia vulgaris (garden loosestrife)
• Marshallia grandiflora (Barbara’s buttons)
• Mimulus ringens (Allegheny monkeyflower)
• Mollugo verticillata (carpetweed)
• Montia chamissoi (Chamisso's miner's-lettuce)
• Oenothera biennis (evening primrose)
• Onoclea sensibilis (sensitive fern)
• Osmunda regalis (royal fern)
• Packera spp. (groundsel)
• Persicaria amphibia (water smartweed)
• Persicaria longiseta (low smartweed)
• Persicaria maculosa (ladysthumb)
• Persicaria pensylvanica (smartweed)
• Persicaria punctata (dotted smartweed)
• Phalaris arundinacea (reed canarygrass)
• Pilea pumila (clearweed)
• Sida hermaphrodita (Virginia mallow)
• Sorghastrum nutans (Indiangrass)
• Spartina pectinata (freshwater cordgrass)
• Trautvetteria caroliniensis (Carolina tassel-rue)
• Triadenum virginicum (marsh St. Johnswort)
• Verbena hastata (blue vervain)
• Xanthium strumarium (common cocklebur)
• Zizia aurea (golden-alexander)

Vines
• Parthenocissus quinquefolia (Virginia creeper)
• Toxicodendron radicans (poison ivy)
• Vitis labrusca (fox grape)
• Vitis riparia (riverbank grape)
• Vitis rupestris (sand grape)

Characteristics and indicators. The sparse vegetation state is characterized by exposed substrate and often represents areas of exposed rock from scour. Exposed sand and soil along shorelines are also represented in this state.

Resilience management. Common Exotic Species • Fallopia japonica (Japanese knotweed) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=LYSA2" target="_blank" title="Open in plants.usda.gov">Lythrum salicaria</a> (Purple loosestrife) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=MIVI" target="_blank" title="Open in plants.usda.gov">Microstegium vimineum</a> (Japanese stiltgrass) • <a class="species-link" href="https://plants.usda.gov/core/profile?symbol=PHAR3" target="_blank" title="Open in plants.usda.gov">Phalaris arundinacea</a> (Reed canarygrass)

Dominant plant species

silver maple (Acer saccharinum), shrub
speckled alder (Alnus incana ssp. rugosa), shrub
river birch (Betula nigra), shrub
common buttonbush (Cephalanthus occidentalis), shrub
silky dogwood (Cornus amomum), shrub
wild hydrangea (Hydrangea arborescens), shrub
common ninebark (Physocarpus opulifolius), shrub
American sycamore (Platanus occidentalis), shrub
eastern sandcherry (Prunus pumila var. depressa), shrub
great laurel (Rhododendron maximum), shrub
swamp azalea (Rhododendron viscosum), shrub
swamp rose (Rosa palustris), shrub
Missouri River willow (Salix eriocephala), shrub
narrowleaf willow (Salix exigua), shrub
black willow (Salix nigra), shrub
silky willow (Salix sericea), shrub
steeplebush (Spiraea tomentosa), shrub

Transition T1
State 1 to 2

This transition pathway can occur as a result of any disturbance that directly impacts an existing forest tree canopy. Examples include abnormal flooding events and/or changes to hydrology which cause increased duration and depth and flooding, increased flood energy and scour, deposition of significant flood transported material, ice, wind, insects, disease, and timber extraction.

Conservation practices

Early Successional Habitat Development/Management
Forest Stand Improvement

Transition T4
State 1 to 3

This transition pathway can occur as a result of any disturbance that directly impacts established woody vegetation including both trees and brush. Examples include abnormal flooding events and/or changes to hydrology which cause increased duration and depth and flooding, increased flood energy and scour, deposition of significant flood transported material, ice, wind, insects, and disease.

Conservation practices

Brush Management
Early Successional Habitat Development/Management
Forest Stand Improvement
Prescribed Grazing

Transition T5
State 1 to 4

This transition pathway can occur as a result of any disturbance that directly impacts all established vegetation as well as soil substrate. Examples include abnormal flooding events and/or changes to hydrology which cause increased duration and depth and flooding, increased flood energy and scour, deposition of significant flood transported material, and ice.

Restoration pathway R1
State 2 to 1

This restoration pathway is a normal successional pathway that can occur in the absence of high-energy flooding disturbance which can scour and remove soil as well as damage established vegetation.

Conservation practices

Brush Management
Riparian Forest Buffer
Tree/Shrub Establishment
Herbaceous Weed Control

Transition T2
State 2 to 3

Conservation practices

Brush Management
Early Successional Habitat Development/Management
Prescribed Grazing

Transition T6
State 2 to 4

This transition pathway can occur as a result of any disturbance that directly impacts all established vegetation. Examples include abnormal flooding events and/or changes to hydrology which cause increased duration and depth and flooding, increased flood energy and scour, deposition of significant flood transported material, and ice.

Restoration pathway R2
State 3 to 2

This restoration pathway is a normal successional pathway that can occur in the absence of high-energy flooding disturbance which can scour and remove soil as well as damage established vegetation.

Conservation practices

Riparian Forest Buffer
Tree/Shrub Establishment
Early Successional Habitat Development/Management

Transition T3
State 3 to 4

Restoration pathway R3
State 4 to 3

This restoration pathway can occur in the absence of high-energy flooding disturbance, especially with low energy flooding that includes the deposition of soil on and around the rocky substrate that is common with riparian zone sparse vegetation communities.

Conservation practices

Riparian Herbaceous Cover
Early Successional Habitat Development/Management

Additional community tables

Table 4. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 5. Community 1.2 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 6. Community 1.3 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 7. Community 1.4 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Supporting information

References

Bailey, R.G. 1995. Description of the ecoregions of the United States.
McNab, W.H., D.T. Cleland, J.A. Freeouf, Keys, G.J. Nowacki, and C.A. Carpenter. 2007. Description of ecological subregions: Sections of the conterminous United States.
US. Department of Agriculture, . 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin..
Virginia Department of Conservation and Recreation, . 2016. Overview of the physiography and vegetation of Virginia.
Woods, A.J., J.M. Omernik, and D.D. Brown. 1999. Level III and IV ecoregions of Delaware, Maryland, Pennsylvania, Virginia, and West Virginia.
Zimmerman, E., T. Davis, G. Podniesinski, M. Furedi, J. McPherson, S. Seymour, B. Eichelberger, N. Dewar, J. Wagner, and J. Fike. 2012. Terrestrial and palustrine plant communities of Pennsylvania, 2nd edition.
Oregon State University. 2016 (Date accessed). PRISM climate data 1981-2010. http://prism.oregonstate.edu.
US Geologic Survey. 2018. Geologic maps of US states.
US Geologic Survey. 2011 (Date accessed). Gap Analysis Program (GAP) National Land Cover, Version 2. https://gapanalysis.usgs.gov/gaplandcover/data/.
Federal Geographic Data Committee, V.S. 2017 (Date accessed). United States National Vegetation Classification database, V2.01. http://usnvc.org/.

Contributors

Matthew Duvall
Ben Marshall
David Verdone
Michelle Clendenin

Approval

Curtis Talbot, 3/10/2021

Acknowledgments

Special acknowledgement and appreciation are extended to (in no particular order): Don Riley, John Chibirka, Yuri Plowden, Dan Dostie, Dan Ludwig, Peter Hoagland, Fred Schoenagel, Phil King, Dave Harper, Scott Smith (Maryland DNR), and Ephraim Zimmerman (Pennsylvania Conservation).

Rangeland health reference sheet

Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.

Author(s)/participant(s)	Matthew Duvall Ben Marshall David Verdone Michelle Clendenin
Contact for lead author	Matthew Duvall Forester – Ecological Data Quality Specialist USDA / Natural Resource Conservation Service Mid-Atlantic and Caribbean Area Soil Survey Region 3 4407 Bland Road, Suite 225 Raleigh, NC 27609 Desk: (919) 873-2119 Mobile: (919) 610-5961 matthew.duvall@nc.usda.gov
Date	09/28/2018
Approved by
Approval date
Composition (Indicators 10 and 12) based on

Indicators

Number and extent of rills:
Presence of water flow patterns:
Number and height of erosional pedestals or terracettes:
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Number of gullies and erosion associated with gullies:
Extent of wind scoured, blowouts and/or depositional areas:
Amount of litter movement (describe size and distance expected to travel):
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):

Dominant:

Sub-dominant:

Other:

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Average percent litter cover (%) and depth ( in):
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Perennial plant reproductive capability:

Download reference sheet

Natural ResourcesConservation Service

Ecological site F148XY029PA

Moist, High Base-Saturation, Riparian Zone, Ecotonal Meadow-Shrub-Forest

Last updated: 3/10/2021 Accessed: 08/29/2026

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General information

MLRA notes

Classification relationships

Ecological site concept

Table 1. Dominant plant species

Natural Resources
Conservation Service

Last updated: 3/10/2021
Accessed: 08/29/2026