Savanna Vs. Grassland: What’s the difference?

Temperate Grassland• Great range of temperature• Adequate, regular

precipitation• Occur approximately

midway between the Equator and Arctic/Antarctic circles

• Nutrient rich soils suitable for cultivation

Savanna• Temperatures remain high

year-round • Distinct wet and dry periods• Occur around the equator • Soils are frequently nutrient

poor and dry but contain many valuable minerals

Temperate grasslands• The temperate grasslands (also

called prairies, steppes, pampas and veld) are found in all four corners of the world

• The largest expanse is the Great Plains of North America

• Grasslands are defined by their semiarid climates, with 10-30 inches of precipitation annually (mostly in snow form depending on latitude)

• Temperatures range from -40 to over 70 F

Grassland communityNative flora: grasses (Big

bluestem ), legumes (Butterfly weed) and composites (Goldenrod)

Native fauna: bison, prairie dogs, coyotes and hawks

Competition is fierce due to limits on available water, and space. Frequent fires burn off much of the grass cover and shift the population numbers around

Grassland community

Big Bluestem grass Butterfly weed

Prairie dog

Grassland resourcesBenefits for humans: rich soil, few

obstacles to development, mineral deposits

Because plants are short-lived, few nutrients are taken out of the soil or lost to erosion

Mild leaching, high organic content, and concentration of calcium carbonate create the most fertile soils in the world (4th most productive biome overall)

Human Settlement in GrasslandsIn the 1800’s much of the grasslands were used for cattle

ranchingLater settlers plowed the land, removing many natural grasses to

make room for crops Today much of the land is still used for farming and herding but

several residents have petitioned to end cultivation in order to spare the ecosystem further degradation

Concerns for Grassland ecosystemsGrasslands are being continuously cultivated

and grazed by large commercial herdsAreas are being excavated for oil, natural gas

and mineral deposits under the soilGrasslands cover 15% of the United States but

nearly all of this area has been settled or cultivated

Human actions in the area have depleted natural resources like soil, gas and oil, caused the loss of acres of habitat and critically endangered many unique species like the Great Plains buffalo

Savannas• Also known as tropical grasslands. They are found in a

wide band on either side of the equator on the edges of tropical rainforests.

• The savanna is characterized by very hot temperatures and distinctive wet and dry periods

• During the winter less than 4 inches of rain can fall but they can receive over 25 inches during the summer months

Savanna Community• Native Flora: Gum Arabic, Bermuda grass, Elephant grass • Native Fauna: Lion, African wild dog,

• Amount of rainfall is the major limiting factor, then growing tall is not necessarily an advantage. Grasses with thick, spongy root systems efficiently suck all the moisture out of the soil and can better survive by becoming dormant between rains.

Savanna Community

Gum-Arabic tree

Bermuda grass

Lion Emu

Resources in the Savanna

• Much of the savanna is grassland adequate for pasture and grazing

• There are many deposits of minerals and fossil fuels under the savanna

• Some of the few tree species that grow there are useful as timber and/or medicine and food sources– Ex. The sap from the Gum Arabic tree is used as a cough

suppressant, skin cream and soda flavoring

Concerns in the Savanna

• Savannas are subject to regular wildfires preventing the establishment of a continuous tree canopy which would prevent further grass growth

• Humans extinguish small regular fires, allowing tree growth to accelerate causing bigger fires

• Overgrazing of the savanna quickly leads to desertification and erosion of vital soil

• The grassland will not longer carry a ground fire and invasion by trees becomes possible.

Humans in the Savanna• Many people living on the savanna today are

either nomadic herders or ranch owners• Some people have cultivated farms by installing

irrigation and practicing crop rotation

References• http//i1.treklens.comphotos5325savana.jpg • https://mvscience.wikispaces.com/file/view/catchmentquality_gundary.jpg/

76618099/catchmentquality_gundary.jpg• http://image.wistatutor.com/content/feed/u592/food_chain%203.jpg• http://www.radford.edu/~swoodwar/CLASSES/GEOG235/biomes/tempgrass/

tempgras.html• http://qwickstep.com/search/grassland-uk.html• http://www.ehow.com/list_5786562_typical-types-temperate-grassland-biome.html• http://www.ucmp.berkeley.edu/exhibits/biomes/grasslands.php#temp• http://www.marietta.edu/~biol/102/grasslnd.html• http://2.bp.blogspot.com/_1HwP9iV9Bsk/SOBle9jwPJI/AAAAAAAAEdg/99Cp3ee66R4/

s320-R/range.jpg• http://www.solpass.org/7ss/Images/cowboyssmaller1.JPG• http://www.usatoday.com/news/nation/2007-08-12-great-plains_N.htm• http://www.blueplanetbiomes.org/savanna.htm• http://www.exploringnature.org/graphics/foodwebs/savannah_foodweb72.jpg• http://www.niconinsurance.com.ng/Images/farming.jpg