Natural Resources
Conservation Service
Ecological site F147XY012PA
Calcareous Loamy Bottomland
Last updated: 9/27/2024
Accessed: 11/21/2024
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): 147X–Northern Appalachian Ridges and Valleys
Major Land Resource Area 147 is in the Middle section of the Valley and Ridge Province of the Appalachian Highlands. Characteristic features include folded and faulted parallel ridges and valleys that are carved out of anticlines, synclines, and thrust blocks. The variability of weathering of the underlying bedrock has resulted in resistant sandstone and shale ridges separated by less resistant limestone and shale narrow to moderately broad valleys. The ridges are strongly sloping to extremely steep and have narrow, rolling crests, and the valleys are mainly level to strongly sloping. The Great Valley is a salient feature of the eastern portion and runs the entire length of the MLRA where it is called the Shenandoah Valley in the south. The western side of the MLRA is dominantly hilly to very steep and is rougher and much steeper than the rolling hills to the east. Parts of the northernmost section of the MLRA were subjected to pre-Illinoian glaciation (>770,000 years ago). Anthracite coal underlies some areas in the north and has been mined since the 1700’s.
Elevation in MLRA 147 generally ranges from 330 to 985 feet (100 to 300 meters) in the valleys and from 1,310 to 2,625 feet (400 to 800 meters) on the ridges and mountains. It is as high as 2,955 feet (900 meters) on some mountain crests and is nearly 4,430 feet (1,350 meters) on a few isolated, linear mountain ridges. Local relief in the valleys is about 15 to 165 feet (5 to 50 meters). The ridges rise about 660 feet (200 meters) above the adjoining valleys. (USDA 2006).
Classification relationships
This ecological site is found in Major Land Resource Area 147- Northern Appalachian Ridges and Valleys, 148. MLRA 147 is located within Land Resource Region S - Northern Atlantic Slope Diversified Farming Region (USDA 2006), and in United States Forest Service ecoregion M221 – Central Appalachian Broadleaf Forest-Coniferous Forest-Meadow Province (Bailey, 1995). In addition, MLRA 147 falls within area #67 of EPA Ecoregion Level III – the Ridge and Valley (US EPA, 2013). The Calcareous Loamy Bottomland is predominantly located in 67a of EPA Ecoregion IV – Northern Limestone/Dolomite Valleys (Woods et. al., 1996).
Ecological site concept
The Calcareous Loamy Bottomland ecological sites occur in the Great Valley and Shenandoah Valley in the eastern side of MLRA 147 on floodplains, terraces, and alluvial fans along small to large rivers and streams. The parent material is alluvium weathered from calcareous parent material such as limestone, dolomite, calcareous sandstones, siltstones, and shales, and marl. Areas are well drained to moderately well drained with the seasonal high water table mostly occurring below 40 inches (102 cm) but can be within 20 inches (51 cm) of the surface in wetter areas. These landscapes are generally flat, with 0 to 3 percent slope. Depth to bedrock is 70 inches (178 cm) or more. The flat slopes with generally well-drained and nutrient rich silt loam and fine sandy loam soils are conducive to agriculture, and many of these areas have been cleared for crop production. The high pH of the underlying soils relative to other alluvial landscapes, and the association with marl, is what distinguishes this site from other floodplain ecological sites in MLRA 147. These areas are subject to occasional flooding as classified by the National Soil Survey Handbook (USDA 2016). This is defined as a 5 to 50 percent chance of flooding in any year or 5 to 50 times in 100 years.
Where forest exists, the vegetation is often a mosaic of forest, woodland, shrubland, and herbaceous communities. Common trees include Platanus occidentalis (American Sycamore), Acer negundo (box elder) and Acer saccharinum (silver maple). Juglans nigra (black walnut), Robinia pseudoacacia (black locust), and Liriodendron tulipifera (tuliptree) may also be common, and indicate successional species after significant disturbance like human settlement and agriculture.
Associated sites
| F147XY013PA |
Poorly Drained Calcareous Bottomland Poorly Drained Calcareous Bottomland |
|---|
Table 1. Dominant plant species
| Tree |
(1) Platanus occidentalis |
|---|---|
| Shrub |
(1) Asimina triloba |
| Herbaceous |
(1) Mertensia virginica |
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