Grasslands

by Krysten Aborn and Jenn Berbine


savanna_3.jpg
African Savanna

Introduction

About one quarter of the earths land is made up of grasslands.Grasslands are usually large, wide open spaces.They are usually found between forests and deserts.There are two different types of grasslands, they are temperate grasslands and tropical grasslands. There are also many types of tropical and temperate grasslands. One type of temperate grassland is also known as a prairie.Most prairies are in the United States. A prairie is usually humid. Dense tall grass grows in the nutrient rich soil. For that reason, prairies are most often used for farming. Very few trees will grow here but if there are trees they will grow near springs or other sources of water. A steppe is another type of temperate grassland. Steppes are found in areas less prone to moisture. The vegetation there is suited to a drier climate and has shorter grass than a prairie. The lack of moisture puts steppes in risk of becoming deserts. The last type of grassland is a savanna. Savannas are tropical grasslands.They have a warmer, drier climate than other types of grasslands. Savannas have seasonal droughts. Therefore, most plant life in a savanna can store water for long periods of time or can lie dormant during a time of drought. Savannas have frequent fires becuase of the dryness. One of the most known savannas is the African savanna.

world_grasslands_map.jpg
map of where grasslands are in the world.
DSC01445grasslandsD.jpg
prairie


Climate

The climate of the grasslands is fairly dry. In winter the climate is hot and dry and it never reaches below 64.4 degrees F (18 degrees C). This set of conditions is classified as the AW in the Koppen clasification. savannas are always found in warm or hot climates. Each type of grasslands usually have a different climate. Tropical grasslands that are usually closeto the equator are hot all year round. Temperate grasslands would have hot summers and cold harsh winters. Praries are usually humid. Savannas have a warmer dryer climate and have seasonal droughts.



Precipitation

The precipitation of a grassland varies of the type of grassland. Grasslands receive more rainfall than a desert but less rainfall than a forest. Most temperate grasslands receive anywhere from 10 to 35 inches of precipitation per year. Savannas can either get more or less precipitation. Usually, savannas receive between twenty and fifty inches of rain per year. The rain comes within a period of six to eight months but is followed by a long drought. However, some savannas can receive as little as six to ten inches annually. The savanna has a rainy and a dry season.


grasslands_rainfall.gif
Amount of rainfall in comparison to other biomes.


xfoodchains.gif
Lion energy pyramid



Plants of the African Savanna

Tropical grasslands like the savanna tend to have more trees than temperate grasslands. Though there are many types of trees, there are also a few different types of grasses. The tree concentration is low and scattered. This means that the trees in the savanna are usually not close together.Most of the vegetation in the savanna is fire-resistant. This is good for the frequent fires in the savanna. Some plant species in the African Savanna are :

Senegal Gum Acacia:

The Senegal Gum Acacia is one of the many types of trees in the African savanna. This tree has gray-green leaves. The many branches on this tree have thorns. Yellow or cream colored flowers grow around the thorns so that the thorns are less easily detected. Many animals such as giraffes, elephants and antelopes eat the leaves of of this tree. The Senegal Gum oozes a sap which can also be called gum. This sap can be used for medicinal purposes and is sometimes used in cream for skin inflammation. This tree can store water for long periods of time which is a good adaptation for the long droughts in the savanna. It can grow up to about 20 meters (60 feet).




Senegal_Gum_Acacia.jpg
Senegal Gum Acacia Tree



Baobab:

This is another type of tree in the African savanna. The baobab can grow to about 25 meters tall (82 feet). One unique thing about these type of trees is that they can survive for thousands of years. All parts of this type of tree can be used. The bark can be used for clothing and rope. The leaves can be used for medicines and the fruit that is often called "monkey bread" can be eaten. People have also used this tree's large trunk for a shelter or place to live.

moz-screenshot-1.jpg
baobab.jpg
baobab tree





Umbrella Thorn Acacia:

The Umbrella Thorn Acacia is one of the most recognizable trees of the African savanna. It has black to gray bark and gnarled branches. It has two types of thorn which are surrounded by clusters of flowers. These thorns prevent animals from eating the leaves but the giraffe is the only animal immune to its thorns. This tree can gow up to 20 meters high. It usually grows in sand dunes and rocky grounds. The Umbrella Thorn Acacia can grow in places of the savanna which only get 1 inch of rain each year. It can also survive with 122° F during the day and frigid temperatures at night.


UmbrellaThornAcacia.jpg
Umbrella Thorn Acacia


Elephant Grass:

This is one of the few types of grass in the African Savanna. It grows in clumps that can reach about 10 feet high. The leaves are two to three feet long and razor sharp.
elephant_grass.jpg
elephant grass



Bermuda Grass:

Bermuda Grass is another type of grass in the savanna. It has green-gray leaves and inflorescent purple stems. Bermuda Grass grow is a think, dense mat and has a deep root system that is ideal for a plant in drought. It can grow in poor soil. It often grows in areas with frequent disturbances such as grazing and fires. This type of grass prefers a warm climate. Bermuda Grass is a very invasive species.
bermuda_grass.jpg
bermuda grass

picture from -http://www.blueplanetbiomes.org/images/bermuda_grass.jpg




Animals of the African Savanna


African Elephant

The African Elephant is the largest mammal in the world. It can grow up to 12 feet and weigh up to 10,000 pounds. They have thick gray skin and long tusks made of ivory ro protect itself from predators.With their size, thick skin and tusks, it is hard for predators to attack them. African Elephants are known to be very social and smart animals. They stay in close range groups which are usually led by a female.They are endangered becuase of hunters and poaches who kill them for their tusks. Normally, African Elephants live for about 70 years. If not hunted they will most likely die when their molars wear down. This enables them to eat. African Elephants are herbivores and eat grasses, leaves and fruits.They use their long flexible trunk to bring food to their mouths.

elepahant.jpg
African Elephant



Lion:

The Lion is sometimes referred to as the "power house of the savanna". It is a very strong predator. The Lion can weigh as much as 420 pounds and grow as long as 10 feet. Lions have a beige colored fur. Male lions have a manes which is rough long fur around their necks. The color of their fur is a good color for sneaking up on prey. It usually blends in with the surroundings. Lions are carnivores and eat small to medium sized mammals such as gazelles, antelopes, buffalo and zebras. Lions have sharp teeth which are made for chewing on meat. They can run up to 40 miles per hour which is good for hunting. Female Lions will most always do the hunting. Lions live in small groups of 4 to 40 lions called prides. Males are the protector of the pride while females take care of the cubs and hunt.

lion.jpg
Lion in the savanna






This video follows a pride of Lions.









Work Cited

"Intro Paragraph information and Climate paragraph information" March 1,2008 www.ucmp.berkeley.edu/exhibits/biomes/grasslands.php
"Lion Energy Pyramid" Online Image March 9,2008 http://www.vtaide.com/png/foodchains.htm
"Prairie" Online Image. March 2,2008 http://images.google.com/imgres?imgurl=http://blogs.bootsnall.com/theglobaltrip/updates/DSC01445grasslandsD.JPG&imgrefurl=http://www.freewebs.com/xpridelandsx/territory.htm&h=480&w=640&sz=73&hl=en&start=12&tbnid=pZ2oU7fU6HZTbM:&tbnh=103&tbnw=137&prev=/images%3Fq%3Dafrican%2Bgrasslands%26gbv%3D2%26hl%3Den
"Biomes - Living Worlds ::." Oracle ThinkQuest Library . 9 Mar. 2008 <http://library.thinkquest.org/C0113340/main.php?section=biomes&topic=grassland&subtopic=tropical&gt;.

"Savanna Animals." Blue Planet Biomes. 9 Mar. 2008 <http://www.blueplanetbiomes.org/savanna_animal_page.htm>.

"Savanna Plants." Blue Planet Biomes. 9 Mar. 2008 <http://www.blueplanetbiomes.org/savanna_plant_page.htm>.

"The grassland biome." UCMP - University of California Museum of Paleontology. 9 Mar. 2008 <http://www.ucmp.berkeley.edu/exhibits/biomes/grasslands.php>.</span>
Allaby, Micheal. Biomes of the Earth. New York: Chelsea House, 2006.


"African Savanna" Online Image. March 1,2008.Environmental Biology.
<http://staffwww.fullcoll.edu/tmorris/elements_of_ecology/images/savanna_3.jpg>

"Senegal Gum Acacia Tree" Online Image. March 2, 2008.
<http://www.saudiaramcoworld.com/issue/200502/images/GUM_3_56172.jpg>

"Baobab Tree"Online Image. March 2,2008.
<http://wso.williams.edu/~cholmes/Africa/baobab.jpg>

"Umbrella Thorn Acacia Tree" Online Image. March 2, 2008.
<http://www.blueplanetbiomes.org/images/UmbrellaThornAcacia.jpg>

"Elephant Grass" Online Image. March 3, 2008.
<http://www.blueplanetbiomes.org/images/elephant_grass.jpg>

"Bermuda Grass. " Online Image. March 5, 2008.
<http://www.blueplanetbiomes.org/images/bermuda_grass.jpg>

"Ngorongoro Male Lions" March 5, 2008. Online Video Clip. You Tube.
<http://youtube.com/watch?v=Ovd02VdmXkk>

"amount of rainfall in comparison to other biomes" Online image. March 2, 2008.
<http://www.mbgnet.net/sets/temp/rainfall.gif>