Prairies of the great plains


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Prairies of the great plains

  1. 1. Prairies of the Great Plains Dr. Mark McGinley Honors College and Department of Biological Sciences Texas Tech University
  2. 2. Grasslands• Communities dominated by grasses – Plants in Family Poaceae• Two main types of grasslands – Tropical Savannah Grasslands • South America, Africa, Australia, Asia – Temperate Grasslands • North America, South America, Europe, Asia
  3. 3. Distribution of Grasslands
  4. 4. Prairies• “Prairie” is the term used to describe temperate grasslands found in North America
  5. 5. Origin of the term “prairie”• The French got there before the English, and they had a word for it: prairie, their name for a meadow. But what they encountered, in what is now Indiana, Illinois, Iowa, and points north and west, was more than your everyday meadow. It was a seemingly endless sea of grass as high as a persons head, teeming with flowers and bugs and other critters. And not a tree in sight.• There was nothing like this in England, and no English word for it. Besides, the French, who were the first Europeans in that part of the country, had already taken to calling it prairie, so prairie it became. In English, it is attested as early as 1773 in the journal of a traveler on the Illinois River: "The lands are much the same as before described, only the Prairies (Meadows) extend further from the river."• By the early 1800s, as more and more travelers and settlers ventured into prairie land, the parenthetical definition was no longer needed. Prairie became a descriptive term for the distinctive flora and fauna of these lands• From Houghton Mifflin Word Origins
  6. 6. Distribution of Prairie in North America
  7. 7. Precipitation Map of USA
  8. 8. Three Main Prairie Types• Prairies can be divided into three main types from the east to the west• Tall Grass Prairie• Mixed Grass Prairie• Short Grass Prairie• Prairie types change from east to west as the climate becomes drier.
  9. 9. Prairie Climates• Prairies are found in temperate climates – Warm summers, cool to cold winters• Most prairie regions receive more precipitation in the summer than they do in the winter• Lower precipitation in the western prairie regions than in the eastern prairie regions
  10. 10. Origin of Prairies• The upwelling of the Rocky Mountains created a rain shadow in the middle of the continent so conditions became too dry for forests.• Most prairie soil was deposited during the last glacial advance that began about 110,000 years ago. The glaciers expanding southward scraped the landscape, picking up geologic material and leveling the terrain.• As the glaciers retreated about 10,000 years ago, it deposited this material. Wind deposits also form an important parent material for prairie soils.• Wikipedia
  11. 11. Vegetation During Last Glacial Maximum
  12. 12. Glacial Deposition
  13. 13. Grasses• Grasses are members of the monocot family Poaceae• _400/Lecture/0pdf/30bPoaceaeBW.pdf
  14. 14. Poaceae• 4th largest family - 620 genera, 10,000 species• most important family (ethnobotanically) important grain crops are all grassesGrasses are thought to have originated in SouthAmerica, but have spread across the world - • first diversified about 70 mya in lateCretaceous in the understories of tropical forests
  15. 15. Vegetative Characteristics of Grasses • jointed, hollow, circular stems • leaves 2-ranked or spiralled • blade, sheath, and ligule • intercalary meristem above nodes
  16. 16. Adaptive Vegetative Features• intercalary meristem - allow plants to respond to grazing & fire• silica in stems - protects leaves from predators• C4 photosynthesis - allows for more efficient photosynthesisin warm and arid climates
  17. 17. Reproductive Characteristics of Grasses• Distinctive flower morphology• Wind pollinated
  18. 18. Tall Grass Prairie• Northern Tall Grasslands – Dominant grass species • big bluestem (Andropogon gerardii) • switchgrass (Panicum virgatum) • Indian grass (Sorghastrum nutans)• Only 5% remains undisturbed – Agriculture – 75% rated as heavily altered
  19. 19. Tall Grass Prairie• Central Tall Grasslands – Most mesic of the tall grass prairie ecoregions • Dominant grass species – big bluestem (Andropogon gerardii) – switchgrass (Panicum virgatum) – Indian grass (Sorghastrum nutans) – Converted to the “corn belt” • Very little remains
  20. 20. Tall Grass Prairie• Flint Hills Tall Grasslands – Shallow soil – Dominant grass species • big bluestem (Andropogon gerardii) • switchgrass (Panicum virgatum) • Indian grass (Sorghastrum nutans) – Not as much has been plowed because of shallow soil depth. – Lots has been grazed
  21. 21. Tall Grass Prairie DominantsBig Bluestem (Andropogon gerardii)
  22. 22. Tall Grass Prairie DominantsSwitchgrass (Panicum virgatum)
  23. 23. Tall Grass Prairie DominantsIndian grass (Sorghastrum nutans)
  24. 24. Mixed Grass Prairie• Northern Mixed Grasslands – Dominant grass species • grama (Bouteloua gracilis) • little bluestem (Schizachrium scoparium) • needle-and-thread grass (Stipa comata) • Western wheatgrass (Agropyron smithii),
  25. 25. Mixed Grass Prairies• Central and Southern Mixed Grasslands – Dominant grass species • little bluestem (Schyzachrium scoparium) • western wheatgrass (Agropyron smithii) • grama grasses (Bouteloua cartipendala) – Only 5% remains intact
  26. 26. Mixed Grass Prairie DominantsLittle Bluestem (Schizachyrium scoparium)
  27. 27. Mixed Grass Prairie DominantsWestern wheatgrass (Agropyron smithii or Pascopyrum smithyii)
  28. 28. Mixed Grass Prairie Dominantswestern wheatgrass (Agropyron smithii or Pascopyrum smithyii)
  29. 29. Mixed Grass Prairie DominantsBlue Grama (Bouteloua gracilis)
  30. 30. Mixed Grass Prairie DominantsNeedle-and-thread grass (Stipa comata)
  31. 31. Short Grass Prairie• Northern Short Grasslands – Dominant grass species • grama (Bouteloua spp.) • needlegrass (Stipa spp.) • wheatgrass (Agropyron spp.) – Only 2% remains intact • 85% grazed or cropland
  32. 32. Short Grass Prairie• Western Short Grasslands – Dominant grass species • grama (Bouteloua gracilis) • buffalo grass (Buchloe dactyloides)
  33. 33. Short Grass Prairie DominantsBuffalograss (Buchloe dactyloides)
  34. 34. Other Prairie Plants
  35. 35. Prairie Plant Root Systems
  36. 36. Prairie Fires
  37. 37. Prairie Animals- Large Grazers Elk Cervus elaphusAmerican Bison Bison bison
  38. 38. Prairie Animals- Small Grazers Prairie VoleMicrotus ochrogaster grasshoppers
  39. 39. Prairie Animals- Mammalian Predators Coyote Canis latrans Prairie Wolf Canis lupus
  40. 40. Prairie AnimalsBlack Tailed Prairie Dog Cynomys ludovicianus
  41. 41. Prairie Animals
  42. 42. Prairie Animals Today