CHAPTER 8: TERRESTRIAL ECOSYSTEMS (BIOMES)

World’s Terrestrial Ecosystems (Biomes)

1. Tundra

2. Taiga (Boreal Forest)

3. Tropical Forests

4. Grassland Biome

5. Desert Biome

The coldest and the driest of all the biomes

Tundra

This biome lies above the Artic Ocean in the world’s highest northern latitudes

Tundra

Tundra comes from the _____ word _____

Finnish, tunturia

Meaning treeless plain

Tunturia

It is noted for its frost-molded landscapes, extremely low temperatures, little precipitation, poor nutrients, and short growing seasons

Tundra

Two Types of Tundra

1. Arctic Tundra

2. Alpine Tundra

Located in the northern hemisphere, encircling the North Pole and extending south to the coniferous forests of the taiga

Arctic Tundra

Known for its cold, desert-like conditions

Arctic Tundra

The average winter temperature of Arctic Tundra

-34 C (-30 F)

The average summer temperature of Arctic Tundra

3-12 C (37-54 F)

A layer of permanently frozen subsoil

Permafrost

Located on mountains throughout the world at high altitude where trees cannot grow

Alpine Tundra

A moist subarctic forest that begins where the Tundra ends

Taiga (Boreal Forest)

Represents the largest terrestrial biome of the world

Taiga (Boreal Forest)

Are characterized by the greatest biodiversity of organisms

Tropical Forests

Are found near the equator with a distinct seasonality: winter is absent, and only two seasons are present

Tropical Forests

Characterized as lands dominated by grasses rather than large shrubs or trees

Grasslands

Two Main Divisions of Grasslands

1. Tropical Grasslands

2. Temperate Grasslands

Grasslands with scattered individual trees

Savannas

It covers almost half the surface of Africa and large areas of Australia

Savannas

Types of Savannas

1. Climatic Savannas

2. Edaphic Savanna

3. Derived Savanna

Savannas which result from climatic conditions

Climatic Savannas

Savannas that are caused by soil conditions and that are not entirely maintained by fire

Edaphic Savannas

The result of people clearing forest land for cultivation

Derived Savanna

Occur in areas in the rain shadow off mountain ranges, along coasts next to cold currents, and deep in the interior of the continents

Desert Biomes

Environmental Variables Affecting the Biomes

1. Sunlight

2. Temperature

3. Water and Dissolved Salts

4. Oxygen

5. Metabolic Waste

6. Nutrients