Natural Resources
Conservation Service
Ecological site F090BY006WI
Wet Loamy Lowland
Last updated: 11/16/2023
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): 090B–Central Wisconsin Thin Loess Dissected Till Plain
The Wisconsin and Minnesota Thin Loess MLRA, Northern and Southern Parts (90A and 90B) correspond closely to the North Central Forest and the Forest Transition Ecological Landscapes, respectively. Some of the following brief overview is borrowed from the Wisconsin Department of Natural Resources ecological landscape publications (2015).
The Wisconsin and Minnesota Thin Loess MLRA, Northern and Southern Parts (90A and 90B) is an extensive glacial landscape that comprised of over 11.1 million acres (17,370 sq mi) throughout central and northern Wisconsin – about 27% of the total land area in the state. This glacial landscape is comprised of a heterogenous mix of loess-capped ground moraines, end moraines with eskers and ice-walled lake plains, and pitted, unpitted, and collapsed outwash plains sometimes interspersed with drumlins from the Illinoian and Pre-Illinoian glaciations. The entire area has been glaciated and nearly all of it is underlain by dense glacial till that impedes drainage. An extensive morainal system – the Perkinstown end moraine – spans most of the width of northern Wisconsin and divides the Northern and Southern Parts of this large landscape. This moraine, which has been sliced by outwash in many places, marks the southernmost extent of the Wisconsin glaciation (Wisconsin’s most recent glacial advance).
North of the Perkinstown morainal system is a loess plain, with a loess mantle 6 to 24 inches thick. The northernmost edge of this landscape is an undulating till and outwash plain with materials deposited by the Chippewa Lobe. Drumlins are common in the northern and northeastern portions. The drumlins are oriented towards the southwest and formed during a glacial episode prior to the most recent glacial advance. Some are covered with glacial till. Pitted, unpitted, and collapsed outwash plains fill the spaces between drumlins. Detached from the major land mass to the northeast is the hummocky Hayward collapsed end moraines, where swamps, ice-walled lake plains, and eskers are common.
Most of the MLRA to the south of the Perkinstown morainal system is an extensive ground moraine with some proglacial stream features including pitted outwash plains, terraces, and fans. A layer of loess 6 to 47 inches thick covers much of the area. Like the Northern Part, all areas of the Southern Part of this MLRA were glaciated, although the southcentral portion is a relatively older till plain with materials from the Illinoian and pre-Illinoian glaciations, not the most recent Wisconsin glaciation. The landforms in the southcentral portion are highly variable. Much of the area topography is controlled by underlying bedrock. Sandstone outcrops and pediments can be found here. Some of the most southern portions of the MLRA are mixed glacial deposits and residuum.
The land surface of the southeastern portion was formed by many small glacial advances and retreats. Morainal ridges protrude through an erosional, pitted outwash-mantled surface. These parallel ridges run in a northeast to southwest orientation and are dissected by many steams.
The continental climate of this MLRA is typical of northcentral Wisconsin, with cold winters and warm summers. The southern boundary of this MLRA straddles Wisconsin’s Tension Zone, a zone of transition between Wisconsin’s northern and southern ecological landscapes. Historically, the mesic forests were dominated by eastern hemlock (Tsuga canadensis), sugar maple (Acer saccharum), and yellow birch (Betula alleghaniensis).
Classification relationships
Major Land Resource Area (MLRA): Wisconsin and Minnesota Thin Loess and Till (Northern and Southern Parts - 90A and 90B)
USFS Subregions: Mille Lacs Uplands (212Kb), Glidden Loamy Drift Plain (212Xa), Lincoln Formation Till Plain - Hemlock Hardwoods (212Qc), Lincoln Formation Till Plain - Mixed Hardwoods (212Qb), Perkinstown End Moraine (212Xe), Rib Mountain Rolling Ridges (212Qd), Brule and Paint Rivers Drumlinized Ground Moraine (212Xc), St. Croix Moraine (212Qa), Rosemont Baldwin Plains and Moraines (222Md), Central-Northwest Wisconsin Loess Plains (212Xd)
Small sections occur in Hayward Stagnation Moraines (212Xf), Green Bay Lobe Stagnation Moraine (212Ta)
Wisconsin DNR Ecological Landscapes: Northwest Lowlands, North Central Forest, Forest Transition, Western Prairie
Ecological site concept
The Wet Loamy Lowland ecological site is scattered throughout MLRA 90A and 90B in depressions and drainageways on outwash, lake, and till plains, moraines, and stream terraces. These sites are characterized by very deep, very poorly or poorly drained soils that formed primarily in loamy deposits including lacustrine, till, alluvium, and residuum. Some sites have mantles or underlying sandy or clayey material. Sites are subject to frequent ponding or occasional flooding during the spring and fall. Soils remain saturated for long periods during the growing season and meet hydric soil requirements. Precipitation, runoff from adjacent uplands, groundwater discharge, and stream inflow are the primary sources of water. Soils range from extremely acid to moderately alkaline.
Wet Loamy Lowland is differentiated from other ecological sites by its deep loamy deposits and very poorly or poorly drained soils. Other very poorly or poorly drained sites have sandy or clayey deposits. pH and available water capacity are often higher in loamy sites than sandy sites and often lower in loamy sites than clayey sites. The poor drainage of this site distinguishes it from other loamy sites.
Associated sites
| F090BY002WI |
Mucky Swamp Mucky Swamp sites consist of deep, highly decomposed herbaceous organic materials. Some sites have mineral soil contact. They are very poorly drained and are neutral to slightly acid. These sites are permanently saturated wetlands. They are wetter and occur lower on the drainage sequence than Wet Loamy Lowland. |
|---|---|
| F090BY011WI |
Moist Loamy Lowland Moist Loamy Lowland consist of deep sandy and loamy deposits derived from a mixture of alluvium, residuum, till, or lacustrine sources. The finer textures allow the soil to stay moist - but not saturated - for sustained periods during the growing season. They are somewhat drier and occur higher on the drainage sequence than Wet Loamy Lowland. |
| F090BY016WI |
Loamy Upland Loamy Upland consist of deep loamy till, alluvium, residuum, lacustrine, or eolian deposits. Sandy deposits of these parent materials, plus outwash, may also be present. The depth to the seasonally high water table ranges from as high as the surface to as low as almost two meters below the surface. A few sites are on floodplains and upland drainageways, where very brief flooding is rare but possible. They are much drier and occur higher on the drainage sequence than Wet Loamy Lowland. |
| F090BY021WI |
Dry Loamy Upland Dry Loamy Upland consist of deep sandy to loamy outwash, alluvium, or till. The water table is deeper than two meters year-round. They are much drier and occur higher on the drainage sequence than Wet Loamy Lowland. |
Similar sites
| F090BY004WI |
Loamy Floodplain Loamy Floodplain are found exclusively on floodplains in loamy alluvium, sometimes underlain by sandy alluvium. Soils are very poorly to moderately well drained and are subject to flooding. Some sites may be saturated for long enough for hydric conditions to occur. They share particle size and sometimes drainage capability with Wet Loamy Lowland, though their landforms are different. The vegetative communities are similar between the two sites. |
|---|---|
| F090BY005WI |
Wet Sandy Lowland Wet Sandy Lowland consist of deep sandy deposits derived from a mixture of outwash, alluvium, and lacustrine sources. They form in seasonally ponded depressions and are saturated long enough for hydric conditions to occur. Some sites are wetlands. They are found in similar landforms with similar drainage as Wet Loamy Lowlands, though their particle sizes are coarser. Wet Sandy Lowland supports vegetative communities with lower nutrient requirements. |
| F090BY007WI |
Wet Clayey Lowland Wet Clayey Lowland form in deep, loamy to clayey deposits derived from a mixture of alluvium, residuum, till, or lacustrine sources. These sites have a seasonally high water table at the surface, and some are subject to occasional ponding. Sustained saturation is enough for hydric conditions to occur. They are found in similar landforms with similar drainage as Wet Loamy Lowland, though their particle sizes are finer. The vegetative communities are similar between the two sites. |
| F090BY014WI |
Loamy Bedrock Upland Loamy Bedrock Upland sites consist of sandy to clayey alluvium, till, or eolian deposits over residuum weathered from bedrock. Bedrock contact occurs within two meters of the surface. Sites have seasonally high water table within a meter of the surface. Perching of the water table may occur as a result of bedrock contact. They are somewhat drier but with similar particle sizes as Wet Loamy Lowlands. The two sites support similar vegetative communities. |
Table 1. Dominant plant species
| Tree |
(1) Acer rubrum |
|---|---|
| Shrub |
(1) Corylus |
| Herbaceous |
(1) Onoclea |
Click on box and path labels to scroll to the respective text.
Ecosystem states
| T1A | - | Stand replacing disturbance that includes fire. |
|---|---|---|
| T1B | - | Removal of forest cover and tilling for agricultural crop production. |
| R2 | - | Deciduous forest community is slowly invaded by conifers. |
| T2A | - | Removal of forest cover and tilling for agricultural crop production. |
| R3A | - | Cessation of agricultural practices leads to natural reforestation, or site is replanted. |
| T3B | - | 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. |
|---|---|---|
| 1.2A | - | Disturbance-free period for 30+ years. |