Post on 04-Jan-2016
description
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