much about the Loess Hills of Western Iowa? This section explores
the makeup of loess soil, the ecosystem, the unique qualities of
the area, and threats to the hills.
The issues facing working
landscapes are especially evident in the fragile Loess Hills of
(pronounced "luss") is a German word meaning "loose"
and it is the name of a type of soil. Loess is a deposit of fine,
yellowish-gray, clay-like which can be found from north
central Europe to eastern China and in the American Midwest. Loess
deposits are especially common at the edges of large river basins
and are generally thought to be made up of material carried by winds
that went through the area during and after .
the Loess Hills of Iowa?
story of the Loess Hills of Iowa started more than 25,000 years
ago when a large glacier began to retreat from the area. As the
glacier melted, water filled the Missouri River valley. When the
water level dropped, large amounts of were left behind. Much
of that silt was swept up by winds and dropped to the east of the
Missouri River Valley. Most of the loess piled up within 210
miles of the river in a corridor running about 200 miles north to
south along the river valley, creating the Loess Hills of Iowa.
makes the Loess Hills of Iowa a unique landscape is the depth of
the loess. Only one other location in the world, near the Yellow
River in China, has loess deposits greater than the 100 to 200 foot
depths in the Loess Hills of Iowa. This makes the Loess hills unique
and globally significant. Endangered animals and rare grasses
can be found on these lands. These hills are very fragile and are
vulnerable to water . Human activity and tree invasion are
also a concern. They cause the Loess Hill's prairie ecosystem to
shrinkseveral species are in danger of extinction.
to the Hills
towns, big cities, farmers, business owners, parks and preserves
combine to make the Loess Hills a huge working landscape. Even though
humans have worked this land for hundreds of years, its unique qualities
have only come into the spotlight in the last 30 years. Current
threats include erosion, mining, , poor
practices, and bad land-use decisions.
the Loess Hills Were Formed
to thirty thousand years ago glaciers were moving and melting over
parts of the Iowa landscape and the states to the north. Due to changes
in temperature, the front of the glaciers would melt in the summer
and huge amounts of meltwater would flow down the Missouri River valley.
Prairie Ecosystem in the Loess Hills
are landscapes where the soil, weather, and other conditions favor
grasses over trees. Although prairie areas can be found anywhere
along the Loess Hills, they dominate the southern and western slopes.
Wetland Ecosystem of the Loess Hills
are places where the soil is saturated with water for at least several
weeks during the year. Many wetlands have shallow standing water
throughout the year, but others have water only during the spring
when heavy rainstorms or melting snow increases the amount of water
in the area.
Woodland Ecosystem of the Loess Hills
are one of three distinct ecosystems found in the Loess Hills of
Iowa. Trees and woodland areas in Iowas original landscape
were limited to places where fires were unlikely to occur and had
plenty of water. More
Check out some of the plants, animals, and insects you might find
in the Loess Hills