Prairie flowers color the landscape
Blazing Star (Liatris pycnostachya) is a colorful and unique looking prairie plant. Its tall slender spike stems support lavender colored flowers during July and August.
To see them in person, I highly recommend taking a journey to the Marietta Sand Prairie anytime during this and next month. You will not have any trouble finding clumps of these spike type flowers as you meander across this fantastic botanical prairie preserve. Do bring a camera or other imaging devices to record what you see.
While at the Sand Prairie, lots of other plants will surround you at all times. Their names may not be known to you, which is okay, as good prairie land guidebooks can help considerably in identification tasks. Professional botanists and prairie land advocates may keep a list of the plant types they view or are likely to expect growing on a plot of land virtually undisturbed by humans.
The Sand Prairie botanical list is well over 250 species, and a few very unique plants such as Adder’s Tongue Fern grow in a small portion of site where upwelling soil moisture creates a special habitat called a fen. Fens could be an entire topic for this column at a future time, just not today. Do some research on your own to learn about prairie fens.
Native prairie lands across the Midwest are today only a tiny remnant of extensive native grasslands that once covered Iowa’s pre-settlement landscape prior to the mid-1800s. About 85 percent of Iowa’s soils once hosted native prairies.
Seventeen percent were woodlands/forests, and the remaining two percent was water either as the Mississippi or Missouri, all interior rivers and many glacially cut and water filled natural lakes. Today, native black soil prairie remnants compose less than one-tenth of one percent of Iowa’s surface acres.
The Marietta Sand Prairie is even rarer due to its sandy soil base. Sand soil profiles offer opportunities for some special prairie plants to thrive that may not necessarily be present in loamy soil types. There is a lot of overlap in prairie plant types, but sometimes sandy soils allow unique green things to thrive in these special conditions.
In the case of the Marietta Sand Prairie, wind was the huge factor that deposited tens of thousands of tons of fine wind borne sands over geologic time into a mini-dune like accumulation. Those sand deposits covered over ancient soil surfaces, called paleosols, which are now deeply buried along the adjacent fields of Knapp Avenue.
When rains fall upon this landscape, sand particles, being relatively large with air spaces between grains, allows water to soak down quickly. However, when that water accumulates at the bottom of the sand profile, and just above the paleosol, which is hard and resists water percolation, water will slowly filter downslope to exit slowly seep toward the surface.
Where did all that wind deposited sand come from? Go back to the last glacial maximum time of about 18,000 years ago when the Wisconsinan glacial system covered all of Canada and the northern portions of the United States. One irregular thrust of an icy lobe extended out of the Dakotas and Minnesota into north central Iowa.
That ice front went as far as present day Des Moines. Along the eastern edge of that ice tongue, only a few miles into Marshall County’s western edge, that ice margin was thinner. As this entire glacial system weakened with the earth going into its natural next interglacial warming period (which we are still in), lots of water flowed out of the base of that glacial ice, and from on top of it, to cut, channel and create the initial drainage ways of the Skunk River, Linn Creek, Minerva Creek and many others.
Flowing water sorts soil particles by the flow rate of the water. Fast water can carry or roll large pebbles, stones, gravels, and sands, silt and clay. When water slows down, only the finest of soil particles remain in suspension.
During glacial retreating summers, water flows were immense. During winter times, freezing weather returned and would reduce but not stop water flow rates. Exposed outwash materials containing lots of sand sized particles were left high and dry. However, tremendous scouring winds coming off the glacier’s surface were able to pick up the sand and lift it into the sky, blowing it downwind to some new location.
As wind speeds varied or slowed, air suspension could no longer hold sand. Sand grains therefore fell out to cover vast areas downwind. The area we now call the Marietta Sand Prairie and surrounding private sections of land got dumped on — in fact, the Sand Road between Albion and Marshalltown has huge deposits of sand. Those wind deposited sands fell out when the wind slammed into the Iowa River bluff, and was forced to go up and lose speed, just like a snow fence slows wind and thus deposits deep snow on the leeward side of that fence.
Sand is still part of the local soil mix. Plants have been able to adapt over time to these growing conditions. In Kansas and Nebraska, sand hills containing prairie plants are common. Less common in Iowa are sand prairies.
Sand reedgrass and western ragweed may find places to grow. Dominant grasses are Little Bluestem, Junegrass, Tall Dropseed and Needlegrass, plus a mix of many others. Flower types include partridge pea, sage, dotted mint, and even prickly pear.
Back in Iowa, as natural rainfall events tended to increase, grasses added were Big Bluestem, Indiangrass and Prairie Cordgrass. Flowers included Blazing Star, Birdfoot Violet, Missouri Goldenrod and Savory Leaf Aster.
The Marietta Sand Prairie Preserve, the original 17 acres, was purchased in 1983 and dedicated as a state preserve on Sept. 6, 1984. This acquisition was made possible by a generous donation from the late Janet Paterson.
Two decades later, an additional 212 acres were acquired from Howard and Gladys Conrad, working in partnership with the Iowa Natural Heritage Foundation, Martha-Ellen Tye Foundation, Pheasants Forever, Resource Enhancement and Protection funds, Iowa Prairie Network and many individual donations.
Over time, re-establishing native grasses and flowers by seeding has been accomplished. The area is managed by the Marshall County Conservation Board using periodic controlled burns in later winter or early spring. The area is open to public hunting each fall in addition to year-round public access for hiking, photography, nature observation, and conservation sponsored field trips.
The Marietta Sand Prairie is located at 1744 Knapp Avenue, which is about three miles west of Albion.
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Having fun with names of wild critters can become a daunting task. A big group of birds we commonly call a flock. A large group of deer or elk are called a herd, but did you know that a group of eagles is a convocation? I didn’t either.
Some group names make sense. Take for instance a swarm of bees, a school of fish, or a pack of wolves. Then there are the weird names that have a history dating back to medieval times, that thankfully are not in common use now. Here are a few to think about: a cete of badgers; a gang or obstinacy of buffalo; a murder of crows; an army of frogs; a gaggle of geese; a parliament of owls; a stench of skunks; a dray of squirrels; a knot of toads, or a big mess of politicians.
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Did you know that while fishing a river or stream, 80 percent of the fish can be found in only 20 percent of those waters? Hint: Learn about underwater fish habitats that a species of finny critter prefers, and increase your chances of having one bite your lure. Cheese baits may be good for catfishing, particularly if your refrigerator needs some tender loving cleaning. Use that as an excuse to go fishing often after you clean the entire refrigerator.
Garry Brandenburg is the retired director of the Marshall County Conservation Board. He is a graduate of Iowa State University with a BS degree in Fish & Wildlife Biology.
Contact him at:
P.O. Box 96
Albion, IA 50005