The document discusses the prairies of the Great Plains of North America. It describes three main types of prairies from east to west - tallgrass prairie, mixed grass prairie, and shortgrass prairie - which differ in their dominant grass species and climate due to decreasing precipitation. The prairies originated around 10,000 years ago after glacial retreat left grasslands too dry for forests to reestablish. Today, only small fragments of intact prairie remain due to agricultural and urban development.

1. Prairies of the Great Plains
Dr. Mark McGinley
Honors College and Department of
Biological Sciences
Texas Tech University

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. Distribution of Grasslands

4. Prairies
• “Prairie” is the term used to describe
temperate grasslands found in North America

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 person's 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. Distribution of Prairie in North
America

7. Precipitation Map of USA

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. 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. 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. Vegetation During Last Glacial
Maximum

12. Glacial Deposition

13. Grasses
• Grasses are members of the monocot family
Poaceae
• http://www.botany.wisc.edu/courses/botany
_400/Lecture/0pdf/30bPoaceaeBW.pdf

14. Poaceae
• 4th largest family - 620 genera, 10,000 species
• most important family (ethnobotanically)
important grain crops are all grasses
Grasses are thought to have originated in South
America, but have spread across the world
- • first diversified about 70 mya in late
Cretaceous in the understories of tropical forests

15. Vegetative Characteristics of Grasses
• jointed, hollow,
circular stems
• leaves 2-ranked or
spiralled
• blade, sheath, and
ligule
• intercalary meristem
above nodes

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 photosynthesis
in warm and arid climates

17. Reproductive Characteristics of
Grasses
• Distinctive flower
morphology
• Wind pollinated

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. 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. 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. Tall Grass Prairie Dominants
Big Bluestem (Andropogon gerardii)

22. Tall Grass Prairie Dominants
Switchgrass (Panicum virgatum)

23. Tall Grass Prairie Dominants
Indian grass (Sorghastrum nutans)

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. 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. Mixed Grass Prairie Dominants
Little Bluestem (Schizachyrium scoparium)

27. Mixed Grass Prairie Dominants
Western wheatgrass (Agropyron smithii or
Pascopyrum smithyii)

28. Mixed Grass Prairie Dominants
western wheatgrass (Agropyron smithii or
Pascopyrum smithyii)

29. Mixed Grass Prairie Dominants
Blue Grama (Bouteloua gracilis)

30. Mixed Grass Prairie Dominants
Needle-and-thread grass (Stipa comata)

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. Short Grass Prairie
• Western Short
Grasslands
– Dominant grass species
• grama (Bouteloua
gracilis)
• buffalo grass (Buchloe
dactyloides)

33. Short Grass Prairie Dominants
Buffalograss (Buchloe dactyloides)

34. Other Prairie Plants

35. Prairie Plant Root Systems

36. Prairie Fires

37. Prairie Animals- Large Grazers
Elk
Cervus elaphus
American Bison
Bison bison

38. Prairie Animals- Small Grazers
Prairie Vole
Microtus ochrogaster
grasshoppers

39. Prairie Animals- Mammalian Predators
Coyote
Canis latrans
Prairie Wolf
Canis lupus

40. Prairie Animals
Black Tailed Prairie Dog
Cynomys ludovicianus

41. Prairie Animals

42. Prairie Animals Today