Virtual Classroom
Guide 9
Science
Sixth Grade

There are many different kinds of plants and animals on the Earth, but only certain kinds are naturally found at any particular place. (We are not counting zoos here!) For example, a cactus is found in the desert, polar bears are found in the Arctic, and elephants are found in central Africa and India. Why don't people living in south Texas have to be on the lookout for polar bears, or why do kids in Minnesota not have to worry about finding giant boa constrictors in their back yards? It is because there are many different climates on the Earth, and different plants and animals have adapted to living in certain conditions. These conditions, such as the range of temperature and rainfall that occur on average in a particular place, are called the climate. Some places are hot, some are cold, some are wet and some are dry. Adaptation means that a plant or animal has acquired certain characteristics to enable it to live in one type of climate or another. Polar bears have heavy fur and fat under the skin to help them withstand the cold. They would have a difficulty trying to survive in a hot climate outside of a zoo.

Plants and animals don't live in isolation, but in communities with other interdependent plants and animals called an ecological community. When you think about it for a moment, you realize that all of the plants and animals in a particular ecological community must be adapted to the same living conditions so that they can all live in the same place.

Click on one of the list to see a biome.

A distinct ecological community of plants and animals living together in a particular climate is called a "biome." Although scientists classify the broad spectrum of ecological communities found on Earth into biomes in different ways, here is a commonly found grouping:

1. Tropical rain forest

2. Tropical Savannah

3. Mid-Latitude Deciduous forest

4. Desert

5. Subarctic Taiga

6. Polar Tundra

Different biomes are so distinct that they can even be seen from space! The map* above shows the "greenness" or amount of green plant material found across the land areas of the Earth in early summer in the northern hemisphere. The six different biomes listed above can almost be separated out by location and "greenness" alone. Tropical rain forests are a mix of light and dark green in the center of the map, tropical savannahs are light green, deciduous forests are light green towards the upper an lower parts of the map, deserts are yellowish everywhere, taigas are mostly dark green, and polar tundras are mostly pinkish. To find out more about each of the biomes, just click on one of the numbered spots on the map.

The polar tundra consists of frozen lands . Little vegetation grows on the thin soils of the tundra. Permafrost, or frozen ground, is common in much of this region. Large portions of tundra can be found across northern Canada and Siberia in Asia. This is the land of the Eskimo and Laplander. It is the summer range for the reindeer, moose, and elk. This land has long winters and summers (midnight sun). Agriculture is impossible except in greenhouses.

The subarctic biome is found poleward (closer to the poles) of the mid-latitude biome. This cold biome (see climograph) stretches across the northern portions of North America, Europe, and Asia. Large population centers (Moscow and Toronto) can be found in the southern portion of this biome, but the northern portion is relatively unpopulated.

The mid-latitude deciduous forest has a variety of vegetation types. This type of forest is cooler than the tropical and desert biomes. Much of the world's population live in this biome. Because this biome is located between the polar regions and the tropics, it is influenced by air masses coming from both directions. Mid-latitude deciduous forests have both warm and cold seasons.

The tropical savanna usually surrounds the region of the tropical rainforest. Like the tropical rainforest, the savanna is hot but has a pronounced summer wet season and a dry winter season .

The vegetation in the savanna consists of tall grasses. You can also find occasional trees wherever tree roots can reach underground water. The dry season makes life difficult for the large animals (lions, elephants, zebras, rhinos, and gazelles) that populate this biome. Birds, insects, and snakes are also common in this biome.

Savanna soils are of better quality than rainforest soils. But the savanna has less rainfall, and plants need water. Large regions of savanna surround the rainforest regions of the Amazon of South America and the Zaire area of Africa. The Everglades of south Florida are another example of tropical savanna. Savanna regions do not support large populations of humans.

Desert biomes are characterized by very little moisture. These dry lands receive less than 40 centimeters of precipitation in a year compared to over 100 centimeters in the rainforest. Deserts can be either hot or cold. The important thing to remember is that deserts are dry. (see climograph)

Deserts can be found in tropical regions where there is little rainfall. If you look at a world map, you can see deserts along the Tropic of Cancer in the Northern Hemisphere (the Sonora Desert of North America and the Sahara Desert and Arabian Desert of northern Africa). In the Southern Hemisphere they can be found along the Tropic of Capricorn (the Atacama Desert of South America, the Kalahari Desert of south Africa, and the Victoria Desert of Australia).

Other deserts can form where mountains receive most of the rain. This is called the rain shadow. The great Gobi Desert of Mongolia has little rainfall because the Himalaya Mountains to the south prevent rainfall from moving to this region.

All deserts have great temperature variation. It is warmer during the day because the sun shines on a place with little shade. High daytime temperatures and cold nighttime temperatures make desert environments very inhospitable (in-hoss-pit-a-bull). They are hard on people. Deserts are also hard on plants. Desert vegetation must be adapted to these extreme conditions. Most of the vegetation in a desert is short grasses, sagebrush, creosote bush, and cactus. Animal life in deserts consists of snakes, turtles, lizards, birds, and nocturnal creatures. Humans living in desert environments raise sheep and goats.

The tropical rainforest is the hot, moist biome we find in equatorial regions. These regions have dense canopies of vegetation often forming three different layers. This canopy of vegetation prevents sunlight from penetrating to the ground and the soil is always shaded. Very little vegetation is found at ground level except for occasional shrubs and small trees.

Information taken from

http://www.cotf.edu/ete/modules/msese/earthsysflr/biomes.html

Virtual Classroom Annex

Biology

Grade 6º

Topic. Biomes

1. Read an study guide 9
2. According to the information on line answer the following questions
3. Define Biome and list the different kinds.
4. Give an example of each biome in Colombia
5. Define Climate
6. Give two examples of animals present in each biome different from the ones on the guide.
7. Looking at the map on line, list 2 places in the world for each Biome

Remember. This paper is due on the day of the guide´s evaluation