North American Grasslands - ASB368

grassland biome

• central US, doesn’t reach past Illinois

• rolling terrains of grass + herbs w/ variable amount of tree cover

• temperature, soil, and rainfall contribute to the dominant grassland scene with abundance of trees and bushes

• wildfires key part of production of grasslands

• trees only usually found in riparian forests

• interiors of continents, no coastlines

• usually form along rainshadows

• often support large-bodied migratory animals

grassland climate

• highly variable:

  • hot summers

    • up to and exceeding 80F

  • cold winters

    • below freezing, snowy and windy

• clear east-west gradient in rainfall (more rain in east)

• southeast-northwest gradient in temperature

tall grass prairie

• ranged from 5’-11’

• Big Bluestem are main grass species

• very homogenous, wall of grass

• gigantic wildfires regular to get rid of excess organic matter that would’ve caused way bigger fires

mixed prairie

• settlers didn’t like flat and exposed nature

• Little Bluestem main species

• favorite height for Bison (optimal for muscle extension from cranium shoulders)

short grass

• higher elevations—>higher plains

• sometimes moisture depleted before end of growing season—>grass dies off—>animals leave prairie

  • fall sometimes brings rain + animals

• Blue Grama and Buffalo Grass dominant grass species

• mostly bison, pronghorn, prairie dogs