NEBRASKAland Magazine
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Nebraska's Saline Wetlands
Cross section of a
stream valley that supports
eastern saline wetlands
LOESS
SOILS
GLACIAL
DRIFT
SOILS
LIMESTONE
DAKOTA
SANDSTONE
PRAIRIE STREAM PRAIRIE
Seep and
Salt Crust
Water Table
Common
Sunfl ower
Prairie
Cordgrass
Western
Ironweed
Saltmarsh
Aster
Inland
Saltgrass
Upward
Saline
Groundwater
Flow
D
akota sandstone, an ancient formation of porous,
rust colored sedimentary rock, underlies the soils of
much of eastern Nebraska. Where streams have cut down
through overlying soils, Dakota sandstone is exposed, and
saline waters from still deeper and older rock formations
are under pressure and rise to the surface as springs
and seeps which flow into depressions in the floodplain.
Repeated evaporation of saline water in these shallow
basins over thousands of years concentrated salts in
floodplain soils, setting the stage for the formation of the
saline wetlands.
Recent work indicates this groundwater was recharged
under climatic conditions colder than present-day or at
higher elevations. Age dating of groundwater sampled
at sites along Rock Creek and Little Salt Creek indicate
recharge occurred from 16,000–37,000 years before the
present. Related research indicates that salt present in the
groundwater may be derived from bedrock units older
than the Dakota, possibly marine bedrock beneath parts
of Kansas.
Compared to other communities, the number of plant
species growing on highly saline soils is small. Each
species has adapted to a particular part of the wetland,
a micro-environment defined by minute variations in
soil saturation and salinity. The idealized saline wetland
shown above illustrates how salt tolerant plants are
distributed throughout a Nebraska saline wetland.
A salt flat may surround the standing water and
saline marsh community. Salt flat soils have high clay
content, are saturated with water, and have the highest
