Big Bluestem likes fire
TALL GRASS PRAIRIE once covered 140 million acres of North America’s plains states. Now less than 4 percent remain nationally. In Iowa, the percentage is less than one-tenth of 1 percent. Iowa native prairie sites in large settings exist now in a handful of preserves dedicated long ago for this purpose. Other Iowa prairies tend to be remnant sites in out-of-the-way places, along former railroad rights-of-way, or the back corners of fields. At this time of year, some road ditches have stands of Indiangrass and big bluestem making their fall time appearance. Fall is when this plants are setting seeds at the end of tall stiff stems. And it those tall spires that wave in the breeze.
The Marietta Sand Prairie is one local prairie site located about three miles southwest of Albion. The original 17-acre preserve was purchased in 1983. An additional 200 plus acres was added a decade ago. It was the very marginal farm lands on this sandy soil setting that has now been transformed into additional prairie by the Conservation Board in cooperation with the Iowa Natural Heritage Foundation.
Central North America, once mistakenly called the Great American Desert, supports three types of grasslands, Tallgrass, mixed grass and short grass. Each of these have species of plants with different responses to adaptations to rainfall. Tall grasses like more rain as is common in Iowa and in a swath from north to south from Canada to eastern Texas. Mixed grasses are found in a belt further west as natural rainfall annually is less. And finally are short grass prairies located still more westerly where even less natural rains occur.
Tall grass prairie is dominated by four native grass species: big and Little bluestem, Indian grass and switchgrass. Pioneers traveling over this landscape inevitably brought change as they discovered rich prairie soils below the surface. After John Deere invented the steel moldboard plow – it could cut tough prairie sod – settling and cultivating the prairie grew by leaps and bounds. In less than one generation, the vast prairie soils were broken, the land settled and made productive for agricultural crops. Iowa lost 28 million acres of prairie between 1800 and 1900.
Below the surface of the soil a significant world exists in and within the roots of prairie plants. Sometimes these roots penetrate 15-25 feet into the soil profile. These deep roots are what stays alive even if fire takes burns the above ground portions completely away. Grasses have the ability to go dormant especially in drought or dry conditions. By doing so they conserve energy for regrowth at a future time when rains return. In the soil profile are thousands of nematodes and other animals, even microscopic ones, that maintain a normal life, turn the soil and aerate it. One handful of prairie soil can have 50 to 100 species of nematodes and a variety of microscopic worms. Little mammals burrow close to the surface. Reptiles evade predators by using vacated burrows.
A native prairie above ground may contain as many as 400 species of plants, 150 species of birds, 39 types of retiles and amphibians and over 30 mammal types. Depending upon a prairies location in the entire plains states ecosystem, common species to observe include rabbits, turkeys, ornate box turtles, upland sandpipers, collared lizards and grasshoppers. Foxes are more elusive as are pocket gophers, coyotes, or deer, Further west one may encounter or see evidence of their passing for Greater prairie chickens, black bears, bison, pronghorn antelope and black-footed ferrets.
Weather, both short and very long term, helped mold grasslands. After the retreat (melting) of continental sized glaciers, tundra plants soon grew in exposed glacial till soils. In time, boreal forests found a niche. Further south in glacial till lands a mix of hardwood trees and conifers might grow. But as the climate grew naturally more dry and warmer, grasses were the plants that dominated. And one factor in maintaining grasses was fire from lightning strikes. Such fires could burn unchecked for hundreds of miles. Of course this was all before settlement times. These fires may have set back or destroyed woody vegetation and set the advantage for grasses. Fires on the open prairie would burn until the fuel source ended at stream or river corridors, rocky outcroppings, a turn in wind direction, or enough rain to cause the fire to go out. And remember that over the eons of geologic time, the decaying plant parts helped build a top soil layer thick in humus at the rate of about one inch per century. It took a lot of centuries to make Iowa’s thick layer of topsoil. Big bluestem can be a reminder to us humans of the natural history of Iowa’s landscape.
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Learning more about prairies and prairie pioneer life will be the focus of PRAIRIE HERITAGE DAY activities at the Grimes Farm and Conservation Center on Saturday, Sept. 24 from 2-5 p.m. The usual pioneer crafts will be re-created including candle dipping, rope making, cider pressing, crosscut sawing, wood carving, flint knapping, barn building, broom making, wool spinning and more. Come see the new prairie land nature scape with its play/learning features. Circle the 24th on your calendar for a great afternoon to celebrate people and prairies.
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Next Saturday, Sept. 17, is the beginning of YOUTH DEER SEASON. An adult mentor who has a valid hunting license can be the instructor to assist a youth in evaluating a hunting scenario for safety, fair chase, and ethical behavior concerning hunting. The idea is to provide a special time before the pressure of later fall hunts takes place. An estimated 10,000 youth will purchase a deer license. It is meant to be a positive outdoor hunting experience while under the watchful eye of an adult. Going deer hunting, seeing deer, and taking a deer successfully may be the goal. Reality is that one has to put in the time in the right places to make this happen. And it may not happen at all. Youth need to be encouraged to be patient in hunting sports, do the right thing, always be legal and never bend to temptations.
A deer may or may not be taken during the Sept. 17 through Oct. 2. If a deer is not harvested then, a youth license is also valid during early or late muzzle loader season or one but not both gun seasons later this fall. All deer legally taken must be reported using the harvest reporting system. One has until midnight of the next day to call in, or use a computer to register the deer. Harvest reports are critical to long term management goals of the Iowa DNR. Don’t risk a ticket for failure to report a deer harvest.
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“The ultimate test of a moral society is the kind of world that it leaves to its children.”
Garry Brandenburg is a graduate of Iowa State University with BS degree in Fish & Wildlife Biology. He is the retired director of the Marshall County Conservation Board. Contact him at P.O. Box 96, Albion, IA 50005.