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Environmental Science. Chapter 8 Sections 1, 2, & 3. GRASSLANDS. A GRASSLAND is an ecosystem in which there is more water than a desert but not enough for a forest GRASSLANDS begin at the edges of desert and stretch to the edges of forests
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Environmental Science Chapter 8 Sections 1, 2, & 3
GRASSLANDS A GRASSLAND is an ecosystem in which there is more water than a desert but not enough for a forest GRASSLANDS begin at the edges of desert and stretch to the edges of forests Grasslands exist in Africa, Central Asia, North America, South America, and Australia In the U.S., grasslands stretch from the Rocky Mountains to forests of the east and from Canada to Mexico
GRASSLAND CLIMATES DESERT GRASSLAND BOUNDARY, is the area between deserts and grasslands where increased rainfall allows grasses to grow If rainfall goes up the desert can become a grassland If rainfall goes down a grassland will become a desert Have hot and dry summers Have cold winters
GRASSLAND ORGANISMS • Grasslands are the most common and different in different parts of the world • How do natural fires help grasslands? • Keep the number of trees and shrubs low • Burn away dead grasses to make nutrients • Animals of North American Grasslands: • Bison, Prairie dogs, Coyotes, Foxes, Snakes, birds of prey.
GRASSLANDS Can have heavy rain followed by drought Plants have become drought-resistant by storing and retaining water Three main types: PRAIRIE, STEPPE, and SAVANNA
STEPPES AND PRAIRIES STEPPES are grasslands of short bunchgrasses that get less than 50cm of rain/yr. Considered to be semiarid deserts Some in SW U.S.
STEPPES AND PRAIRIES PRAIRIES are grasslands characterized by rolling hills, plains, and sod-forming grasses In the U.S., prairies are called the Great Plains In Russian, Prairies are called Steppes Veldt in South America Pampas in Argentina Known as the “Breadbaskets”
STEPPES AND PRAIRIES Steppes – Receive 25cm to 50cm of rain/yr Steppes – Temperatures -5ºC to 30ºC/yr Prairies – Receive 50cm to 75cm rain/yr
STEPPES AND PRAIRIES PRAIRIES have sod-forming grasses because the amount of rain that falls An example is a Lawns When roots of the grass die, they form a rich organic material called HUMUS STEPPES have bunchgrasses, which are short, fine bladed grasses that grow in a clump
STEPPES AND PRAIRIES Animals adapt by migrating, hibernating, or burrowing underground Plants use the wind to disperse seeds Over grazing helps create Dust Bowl
https://www.youtube.com/watch?v=guTek7ipD4U https://www.youtube.com/watch?v=o7Uwg8BT6qQ
SAVANNAS • SAVANNAS are tropical or subtropical grasslands ranging from dry scrubland to wet, open woodland. • Savannas occur in Africa, from India to SE Asia, and in Africa from the Sahara to Kalahari deserts to the Southern tip
SAVANNAS Rainfall can be as much as 150cm/yr, but usually falls in short raining season Usually hot and dry Plants grow runners, long horizontal stems above or below ground. Grasses grow in tufts, which are large clumps of tall, coarse grass.
SAVANNAS Animals eat food by the Vertical Feeding Pattern – eating vegetation at different heights Fig 8.10 Animals include gazelle, giraffe, rhinoceroses, elephants, and zebra
