Natural Resources
Conservation Service
Ecological site F089XY003WI
Sandy Floodplains
Last updated: 9/27/2023
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): 089X–Wisconsin Central Sands
The Wisconsin Central Sands (MLRA 89) corresponds closely to Central Sand Plains Ecological Landscape published by the Wisconsin Department of Natural Resources (WDNR, 2015). Much of the following brief overview of this MLRA is borrowed from that publication.
The Wisconsin Central Sands MLRA is entirely in Wisconsin. The total land area is 2,187,100 acres (3,420 square miles, 8858 square kilometers). It is bordered to the east by Johnstown-Hancock end moraines, which were pushed to their extent by the west side of the Green Bay Lobe (Clayton & Attig, 1999). It is bordered to the southwest by highly eroded, unglaciated valleys and ridges. The dominant feature of this MLRA is the remarkably flat, sandy plain, composed of lacustrine deposits and outwash sand, that was once the main basin of Glacial Lake Wisconsin. It also features extensive pine and oak barrens and wetland complexes.
Glacial Lake Wisconsin was fed primarily by glacial meltwater from the north and east. The lake deposited silt overlain by tens of meters of sand (Clayton & Attig, 1989). The silty layers are closer to the surface in some areas, where they impede drainage and contribute to the formation of extensive wetland complexes. It is believed that Glacial Lake Wisconsin drained within several days after a breach in the ice dam that supported it. The catastrophic flood that followed flowed to the south and carved the scattered buttes and mesas protruding from the sandy plain in the southern portion of this MLRA. Before vegetation established after glacial recession, strong winds formed aeolian sand dunes that now support xeric pine and oak stands within the Wisconsin Central Sands.
The surface of the northwestern portion is mostly undulating. The sandy surface sediment was mostly deposited by meltwater during the Wisconsin glaciation. Gentle hills are a result of underlying bedrock topography. Valleys and floodplains are formed by stream action. The underlying bedrock controls the water table elevation and contributes to the formation of numerous wetlands.
Historically, the Wisconsin Central Sands were dominated by large wetland complexes, sand prairies, and oak forests, savannas, and barrens. Some pine and hemlock forests were found in the northwest portion. The Wisconsin Central Sands was subject to frequent fires, leading to today’s need for prescribed burns to maintain the area.
Classification relationships
Major Land Resource Area (MLRA): Wisconsin Central Sands (89)
USFS Subregions: Central Wisconsin Sand Plain (222Ra) and Neillsville Sandstone Plateau (222Rb)
Ecological site concept
The Sandy Floodplains ecological sites occurs on floodplains along the rivers and streams that dissect expansive sandy outwash plains and lake plains in MLRA 89. They’re primarily (but not exclusively) found along the Yellow, Baraboo, and Wisconsin Rivers and their tributaries. These sites are characterized by very deep, poorly to moderately well drained soils formed in sandy alluvium. They’re subject to frequent periods of flooding, primarily in the spring and fall. Some sites are subject to frequent ponding. Water source is primarily stream overflow, but precipitation, runoff from adjacent uplands, and groundwater discharge are also significant waters sources. These sites range from very strongly acid to neutral. Some sites are wetlands.
This ecological site differs from Loamy Floodplains based on sandy parent materials and family particle size class. The sandy materials yield a lower pH and decreased available water capacity, which may limit vegetative growth on the sites.
Similar sites
F089XY005WI |
Wet Sandy Bedrock Lowlands Like Sandy Floodplains, Wet Sandy Bedrock Lowlands consist of sandy alluvium. These sites are underlain by loamy residuum. Bedrock occurs within 100 cm and perches the water table. Soils are poorly drained and subject to ponding. These sites are found in the northwestern portion of the Wisconsin Central Sands MLRA where the depth to bedrock is shallow. The vegetative communities found on these sites are very similar to those found on Sandy Floodplains. |
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F089XY006WI |
Wet Sandy Outwash Lowlands Wet Sandy Outwash Lowlands consist of deep sandy deposits derived from a mixture of outwash, alluvium, and lacustrine sources. They are very poorly to poorly drained, remain saturated for much of the growing season, and are subject to frequent ponding. These sites are primarily found in the eastern half of the Wisconsin Central Sands MLRA. The vegetative communities found on these sites are very similar to those found on Sandy Floodplains. |
F089XY007WI |
Wet Siliceous Sand Lowlands Wet Siliceous Sand Lowlands consist of deep sandy deposits sourced primarily from the weathering of sandstone high in silica. The weathered sand was deposited by rivers or glacial lakes. They are very poorly to poorly drained and remain saturated from much of the growing season. Some are subject to ponding. These sites are primarily found in the western half of the Wisconsin Central Sands MLRA. The vegetative communities found on these sites are very similar to those found on Sandy Floodplains. |
F089XY004WI |
Loamy Floodplains Loamy Floodplains are found exclusively on floodplains in loamy alluvium underlain by sandy alluvium. Soils are somewhat poorly to poorly drained and are subject to flooding. These sites occur primarily along tributaries to the Yellow River in central Wood County and along the Lemonweir River. The vegetative communities associated with Loamy Floodplains prefer a similar soil moisture regime as those of Sandy Floodplains but have higher nutrient requirements. |
Table 1. Dominant plant species
Tree |
(1) Pinus strobus |
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Shrub |
(1) Pinus strobus |
Herbaceous |
(1) Rubus hispidus |
Click on box and path labels to scroll to the respective text.
Ecosystem states
T1A | - | Clearcutting, or stand replacing natural disturbance. |
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R2A | - | Absence of disturbance |
State 1 submodel, plant communities
1.1A | - | Major flooding event depositing new sediment |
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1.2A | - | Long period without major flooding |