Bot1320 Chapter 5 Home on the Range
  1. Loss of prairies due to farming and disturbances such as grazing by cattle has reduced available habitat for prairie residents.
    • • Due to greater precipitation on the eastern portion of the Great Plains, most of the tallgrass prairies have been plowed for farming.

      Mush of the remaining grasslands on the western portion have been grazed by cattle.

    • Bison help shape the landscape by creating wallows, depressions where water-loving plants such as Prairie Dropseed (Sporobolus heterolepis) as well as animals such as Painted Turtle can find temporary moist soil.

      Replacing bison with cattle for grazing is a kind of disturbance that can impact the ecosystem.

      Many introduced species become invasive under disturbed conditions.

    • • Cattle do not make wallows, thus reducing the diversity of micro-habitats that the bison created.

      The fenced-in cattle also preferentially eat forbs such as Butterfly Milkweed (Asclepias tuberosa, or "ice-cream plant"), further decreasing the diversity of the plant community.

    • Introduced species brought over from elsewhere may become invasive if it finds a lack of predators or diseases in the new environmnet, or possesses unique traits that allow them to out-compete native species.

      The Crested Wheatgrass introduced from Asia is more adapted to heavy grazing, thus can displace our native Bluebunch Wheatgrass in overgrzed areas.

  2. Prairies are home to large grazing herbivores such as bison and pronghorns.
    • • Large herbivores such as bison are ruminants that host symbiotic microorganisms in their digestive system.

      Multiple compartments in their stomach allow these ruminants to digest the tough fibers that make up their diet.

      Grasses have growth patterns that allow them to survive the constant grazing.

    • Ruminants have microbes in their stomachs to facilitate digesting tough cellulose fibers.

    • • The stomach of a ruminant has four chambers.

      1. The grass enters the rumen and the reticulum, where symbiotic microorganisms digest the cellulose.

      2. The ruminant periodically regurgitates and rechews the cud, to further break down the fibers.

      3. The cud is reswallowed, and moves to the omasum, where water is removed.

      4. The cud finally passes to the abomasum for final digestion by the ruminant's own enzymes.

    • • Plants have growth regions called meristems.

      Apical meristems are located at the tips of roots (below ground) and shoots (above ground), promoting their elongation, a process called primary growth.

      Lateral meristems add thickness to woody plants, a process called secondary growth.

      Grasses possess intercalary meristems that allow them to regrow if the apical meristems are cut off.

  3. Other prairie residents include birds, and rodents.
    • • Many species of birds call the prairies home.

      Ground-nesting birds include many species that require large expanses of grasslands, grouse that need clearings, and killdeer.

    • • Some birds are grassland specialists.

      The Grasshopper Sparrow, Upland Sandpiper, and Bobolink require 125 acres of open grassland, uninterrupted by trees

      The Dickcissel is less demanding, but still requires 50 acres.

      Therefore, these birds are unlikely to be seen nesting in the Kirt Prairie at COD, but may be seen at the 1,787-acre Springbrook Prairie.

    • • Four species of grouses are native to the Great Plains.

      The Sharp-tailed and Greater Sage Grouse occupied the short and mixed-grass habitats to the west, while the Greater and Lesser Prairie Chicken roamed the taller grasses to the east of the plains.

      All four species perform a mesmerizing courtship ritual: males congregate in clearings alled leks, and compete in mating dances by twirling and bobbing while puffing up neck pouches to make a booming sound.

    • Killdeer (Charadrius vociferus) are plovers that have adapted to human disturbance and nest in grass in early spring.

      Prairie management practices such as prescribed burns should consider impact on such ground-nesting birds.

      Parents perform a broken-wing display if an intruder approaches the nest, drawing the potential predator away.

    • This Thirteen-lined Ground Squirrel is an insectivore, feeding on insects, though most other rodents have more plant-based diets.

      This is an endemic species, found exclusively in the Great Plains and surrounding areas.

      Another endemic species is Prairie Vole (Microtus ochrogaster)

  4. Complex symbiotic relationships form in the above-ground communities of prairies.
    • • Complex symbiotic relationships form among prairie species, such as this American Painted Lady sipping nectar on Blue Vervain (Verbena hastata) and pollinating the flower in the process.

      • Mutualistic: both organisms benefit from the interaction.

      • Parasitic: a parasite feeds off a host without killing the host.

      • Predator/prey: the predator eats the prey.

    • Bees such as this Eastern Carpenter Bee are mutualistic pollinators, though sometimes a plant may trap the pollinator.

      The Common Milkweed (Asclepias syriaca) has pollen tucked away in packets called pollinia.

      A honeybee obtaining nectar inserts its legs in the slits surrounding the pollinia, usually carrying off the packets, but sometimes getting stuck.

      Butterflies such as Monarch (Danaus plexippus) can be mutualistic pollinators as adults, though the juvenile caterpillars are predators as leaf eaters.

    • Some beetles such as this female Baptisia Weevil ovipositing on a pod of White Wild Indigo (Baptisia leucantha) are parasites.

      After eggs hatch, larvae feed on the seeds inside, maturing into adults within the pod.

      Other weevils such as the Sunflower Headclipping Weevil may also serve as pollinators when the female is busy chopping off the flower head.

    • This Banded Garden Spider is among a wide diversity of predators roaming the Great Plains.

      • Amphibians such as American Toad and Western Chorus Frog feed on insects.

      • Insectivorous rodents include the Thirteen-lined Ground Squirrel.

      • Raptors such as Burrowing Owl and Red-tailed Hawk catch rodents and other small animals.