325500 To develop an understanding of the interdependence of all organisms and the need for conserving natural resources

The earth's biosphere is variously subdivided according to specific characteristics.

3255L4:0.00 To understand the biotic and abiotic factors that determine major biomes of the biosphere

4.01 identify the physical factors that determine the major biomes of the earth.
4.02 compare biotic factors that are associated with two contrasting biomes.
4.03 describe the relationship of altitude and latitude to biome formation.
4.04 define and describe the major biomes of Tennessee and North America.

Gaining information, critical thinking, and analyzing

45 minutes

I. There are six major types of terrestrial communities called biomes
II. Biomes are identified by their dominant vegetation
A. Tundra
1. Lichens
2. Mosses
3. Shrubs
B. Taiga
1. Coniferous forest
C. Temperate deciduous forest
1. Trees which regularly lose their leaves
D. Tropical rain forest
E. Grassland
F. Desert
III. Temperature and moisture influence the type of vegetation that will occur in an area.
A. Tundra
1. Low average temperature
2. Low precipitation
a. snow
B. Taiga
1. Slightly warmer than tundra
2. Although there is little precipitation, low evaporation makes for very wet areas
C. Temperate deciduous forest
1. Found in temperate regions
2. Leaves regularly fall from tree
D. Tropical rain forest
1. Occur in equatorial regions
2. Temperature is about twenty-five degrees all year
3. Rainfall is heavy
E. Grassland
1. Occur in both temperate and tropical regions that receive between twenty-five and seventy-five cm of rainfall per year.
F. Desert
1. Receives less than twenty-five cm of rainfall per year.
2. Has very little vegetation

SIGNIFICANT TERMS:

Tundra, taiga, temperate deciduous forest, tropical rain forest, grassland, desert

If you suddenly awakened from a deep sleep and found yourself in a place with hot dry sand and cactus, what kind of place would you think you were in? (Desert) If you suddenly found yourself in a tropical rain forest, what kind of plants would you expect to see? (Palm trees)

Plants tell us a lot about our surroundings. You have just shown me that you can distinguish between a desert setting and a tropical setting based on the types of plants you see. Scientists have found that there are six major types of terrestrial communities called biomes. Biomes are identified by their dominant vegetation, which is influenced by temperature and moisture.

The tundra is typified by lichens, mosses, and shrubs. No tree grows in this region. The average yearly temperature is too low, and there is very little precipitation. The precipitation that does fall is mostly in the form of snow. (Converted to rain, the annual precipitation would be about 12cm per year.) From this information, what can you say about lichens? (They don't need very much water to live.)

The taiga (TI guh) is slightly warmer than the tundra. Although there is little precipitation, low evaporation makes for very wet areas. Cone-bearing trees, such as pine and spruces, grow well in the taiga. A forest made up of cone-bearing trees is called a coniferous forest.

The temperate deciduous forest is made up of trees which regularly loose their leaves. (Have students name trees that shed their leaves every fall.) This type of forest is found in temperate regions. Temperate regions are those that have definite seasons.

The tropical rain forest occurs in equatorial regions where the temperature is about twenty-five degrees Celsius all year. Rainfall is heavy, about 200cm per year. Can you name some places where this biome occurs? (Inform students that a jungle is not a tropical rain forest. A jungle is a very dense growth resulting from secondary succession after a rain forest has been cleared. Rain forests are found in Central and South America, central Asia, Africa, and parts of Australia.

Grasslands occur in both temperate and tropical regions that receive between twenty-four and seventy-five cm of rainfall per year. As the name implies, the dominant vegetation in this biome is grass.

The desert biome receives less than 25cm of rainfall per year. It has very little vegetation. Deserts are found in western U.S., Africa, India, Asia, South America, and Australia.

Biomes are terrestrial communities identified by their dominant vegetation. There are six biomes in the world. They are the tundra, the taiga, the temperate deciduous forest, the tropical rain forest, the grassland, and the desert.

BOOKS:
Holt General Science, Elements of Ecology