Natural Resources
Conservation Service
Ecological site F105XY012WI
Shallow Loamy-Silty Upland
Last updated: 2/23/2024
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): 105X–Upper Mississippi River Bedrock Controlled Uplands and Valleys
The Northern Mississippi Valley Loess Hills area corresponds closely to the Western Coulees and Ridges and Southwest Savanna Ecological Landscapes. Some of the following brief overview is borrowed from the Wisconsin Department of Natural Resources Ecological Landscape publication (2015).
Fifty-two percent of the Upper Mississippi River Bedrock Controlled Uplands and Valleys MLRA is in Wisconsin; Iowa, Minnesota, and Illinois contain the rest. This region is the only area in Wisconsin that has not been covered by glaciers within the past 2.4 million years. The Wisconsin portion of this MLRA is approximately 7.4 million acres (11,600 square miles). The landscape is characterized by dissected topography with deeply-incised, steep-walled valleys between bedrock controlled ridges.
Though it’s called the “Driftless Region”, some glacial drift is found in the major river valleys of this region in the form of outwash, deposited by proglacial streams of glacial meltwater. Wisconsin’s most recent glaciations also impacted the sediment of the area through the deposition of loess. After the glacier receded and before vegetation established, the bare surfaces of the glaciated areas were highly susceptible to wind erosion. As a result, a veneer of loess (wind-blown silt) was deposited over the entire region. The thickest deposits—nearly five meters—are on ridges near the Mississippi River and gradually thin moving eastward. The loess caps in Dane and Green counties are generally 0.5-1.5 meters deep. Much of the loess has eroded downslope and collected in floodplains.
Bedrock is shallow throughout this MLRA and is a major influence on topography and hydrology. Most of the MLRA has bedrock within two meters, except in the deep river valleys that are filled with outwash and alluvium materials. Sandstone is the dominant bedrock type in MLRA 105, but the southernmost portion is dominated by dolomite. Military Ridge is an escarpment that straddles the boundary between sandstone and dolomite bedrock. The sandstone north of the ridge is weaker than the erosion-resistant dolomite south of the ridge. The sandstone is deeply cut and dissected into steep slopes and valleys. The dolomite-controlled ridges tend to be less dissected and broader with more gentle, south sloping topography. Geomorphic and fluvial processes formed these landscapes by way of sheet wash, soil creep, and flowage. These processes eroded the hillslopes, cut into bedrock, and transported the debris to streams, forming floodplains and terraces.
Underfit streams are common in MLRA 105, especially in the southern portion. These streams currently occupy large river valleys—especially those of the Black, Chippewa, Mississippi, and Wisconsin Rivers—that were carved by proglacial meltwater streams carrying much larger quantities of water than what’s present today. As the climate dried, waterflow decreased and the valleys filled with alluvial sediment. Narrow meanders were formed by the shrinking streams and are often dissimilar to the meanders of the larger valleys they occupy. Fluvial landforms – including terraces, oxbow lakes, sandbars, eroding bluffs, and large floodplain complexes – are found within these large valleys and are subject to varying flooding frequencies, intensities, and durations.
Karst topography formed in this region from dissolution of carbonate bedrock by surface and groundwater. Dolomite and limestone are more easily affected by dissolution, but karst topography also formed in sandstone. Erosion by water (stream meanders, rain/runoff, and groundwater), wind, and frost weaken joints and bedding planes that can cause collapse. In addition, sandstone materials collapse into cavities in underlying dolomite or limestone.
Historically, MLRA 105 was dominated by oak forests and oak openings making up more than 50% of the area. Prairies were significant and covered 32% of the area south of Military Ridge. Maple-basswood forests covered 19% of the area north of Military Ridge. Dominant tree species were white oak (Quercus alba), bur oak (Quercus macrocarpa), black oak (Quercus velutina), and sugar maple (Acer saccharum).
Classification relationships
Relationship to Established Framework and Classification Systems:
Habitat Types of S. Wisconsin (Kotar, 1996): Acer saccharum-Tilia/Cornus racemose(Arismaea) [ATiCr(As)], Acer saccharum-Tilia/Desmodium [ATiDe], Acer saccharum-Tilia/Arismaea(Desmodium) [ATiAs(De)], Acer saccharum-Acer rubrum/Viburnum [AArVb], and Pinus strobus/Vaccinium-Hammamelis [PVHa].
Biophysical Settings (Landfire, 2014): This ES is largely mapped as North-Central Interior Maple-Basswood Forest, North-Central Interior Dry-Mesic Oak Forest and Woodland, North-Central Interior Dry Oak Forest and Woodland, and Paleozoic Plateau Bluff and Talus Woodland
WDNR Natural Communities (WDNR, 2015): This ES is most similar to Southern Mesic Forest as described by the Wisconsin DNR.
Hierarchical Framework Relationships:
Major Land Resource Area (MLRA): Upper Mississippi River Bedrock Controlled Uplands and Valleys (105)
USFS Subregions: Menominee Eroded Pre-Wisconsin Till (222La), Melrose Oak Forest and Savannah (222Lb), Mississippi-Wisconsin River Ravines (222Lc), Kickapoo-Wisconsin River Ravines (222Ld), Mineral Point Prairie-Savannah (222Le)
Wisconsin DNR Ecological Landscapes: Western Coulee and Ridges, Southwest Savannah
Ecological site concept
The Shallow Loamy-Silty Upland ecological site occupies approximately 1,443,000 acres in MLRA 105, or about 21% of total land area. It is the second-most extensive ecological site in MLRA 105 behind Loamy Silty Uplands. It is found in upland positions across diverse landforms throughout MLRA 105.
These sites are characterized by moderately well to well drained loamy soils. Bedrock contact is found within 3 feet (1 meter) of the soil surface. The bedrock acts as a root restricting layer and can limit root growth and perch water. These sites may be vulnerable to tree trips.
Associated sites
F105XY008WI |
Moist Loamy-Clayey Lowland These sites form in loamy and clayey materials. They are somewhat poorly drained. They can sometimes be found adjacent to Shallow Loamy-Silty Upland in lower landscape positions. |
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F105XY003WI |
Wet Loamy-Clayey Floodplain These sites form in deep, loamy alluvium deposits along floodplains, especially those along smaller tributaries to the Chippewa, Black, and Wisconsin rivers. They support vegetation tolerant of seasonal flooding. They are sometimes saturated enough for hydric conditions to occur. They can e found in floodplains adjacent to Shallow Loamy-Silty Upland. |
Similar sites
F105XY013WI |
Loamy-Silty Upland These sites form in loamy to silty materials, often silty loess and residuum. They are moderately well to well drained. They are very similar to Shallow Loamy-Silty Upland but lack bedrock contact within one meter of the soil surface. |
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R105XY010WI |
Shallow Mollic Loamy-Silty Upland These sites form in loamy to silty materials, often silty loess and residuum. They have deep, dark surfaces and bedrock contact within one meter of the soil surface. They are well drained to somewhat excessively drained. They are very similar to Shallow Loamy-Silty Upland but have deeper surface horizons of organic-enriched soil (mollic rather than ochric epipedons). |
F105XY015WI |
Shallow Clayey Upland These sites form in sandy materials deposited by wind, water, gravity, or weathered from sandstone bedrock. They have bedrock contact within one meter of the soil surface. They are somewhat excessively to excessively drained. They are found in similar landscape positions as Shallow Loamy-Silty Upland but have coarser soil textures with a lower nutrient status. |
Table 1. Dominant plant species
Tree |
(1) Acer saccharum |
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Shrub |
Not specified |
Herbaceous |
(1) Parthenocissus quinquefolia |
Click on box and path labels to scroll to the respective text.
T1A | - | Stand replacing disturbance that includes fire. |
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T1B | - | Removal of forest cover and tilling for agricultural crop production. |
R2A | - | Deciduous forest community is slowly taken over by shade tolerant maples and other species. |
T2A | - | Removal of forest cover and tilling for agricultural crop production. |
R3A | - | Cessation of agricultural practices leads to natural reforestation, or site is replanted. |
R3B | - | Cessation of agricultural practices leads to natural reforestation, or site is replanted. |
State 1 submodel, plant communities
1.1A | - | Light to moderate intensity fires, blow-downs, ice storms. |
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1.2A | - | Disturbance-free period for 30+ years. |
State 2 submodel, plant communities
2.1A | - | Immigration and establishment of red oak and red maple. |
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2.2A | - | Immigration and establishment of red oak and red maple. |
2.3A | - | Clear cutting or stand-replacing fire. |