Organisms and the Environment

Chapter Six: Biomes

• 6.1 Climates and Biomes

• 6.2 Deserts and Grasslands

• 6.3 Temperate Forests and Rainforests

• 6.4 Taigas and Tundras

Investigation 6A

• What causes different microclimates within an ecosystem?

Environments Around School

6.2 Deserts

• A desert is a climate region that averages less than 35 cm. of rainfall per year.

• Due to a lack of clouds, deserts get more than twice as much incoming sunlight as other regions.

Why don’t deserts have cloud cover?

6.2 Rainshadow deserts

• One desert found in eastern Washington state, is the result of the “rainshadow effect.”

• Moist air rises as it travels up the western slope of the Cascade mountains range and cools, causing lots of rain.

• By the time the air reaches the eastern side, there is very little moisture left.

6.2 Desert life

• Many different kinds of organisms have adapted to desert life.

• In fact, only the tropical rainforest biome contains a greater number of plant and animal species.

6.2 Grasslands

• Grasslands are found on every continent except Antarctica.

• There are two types of grasslands:– savannas (tropical

grasslands), and – temperate grasslands.

Which type of grassland is found in South America?

6.2 Grasslands

• Savannas are characterized by two seasons: rainy and dry.

• During the rainy season, from 50 to 127 cm. of rain can fall.

• This season is followed by a drought, in which wildfires can occur.

• Fires and poor soil conditions prevent the growth of most trees.

6.2 Grasslands

• In some areas, trees grow only on termite mounds.

• The isolated trees found in savannas have cork-like bark that protect against fire damage.

6.2 Grasslands

• Many large mammals of the savanna, including wildebeest have long legs that enable them to outrun fires.

6.2 Grasslands

• Around the world, grasslands go by different names.

Which type of grassland is closest to where you live?