1. Biomes

2. Biomes Scientists group ecosystems into larger areas called biomes.
Biome: a large region characterized by a specific type of climate and certain types of plants and animal communities.

3. The World’s Major Terrestrial Biomes

4. Major Biomes
The major biomes are divided into Terrestrial (ground) and Aquatic (water) biomes.
The aquatic biome can be divided into both Marine (saltwater) and Freshwater biomes.
The Terrestrial Biomes are:
Tropical Forest
Temperate (Deciduous) Forest
Taiga (Boreal or Coniferous Forest)
Savannah
Grasslands (also called Prairie, Steppe, or Pampas)
Desert
Tundra

5. Further Classification
Some biologists define more than seven terrestrial biomes, adding Chaparral, Mountain, Island, or Tropical Dry Forest.
Biomes are often known in English by local names. For example, a temperate grassland or shrubland biome is known commonly as steppe in central Asia, prairie in North America, and pampas in South America. Tropical grasslands are known as savanna in Australia, whereas in Southern Africa it is known as veldt (from Afrikaans).

6. Biomes and Vegetation
Biomes are described by their vegetation because plants are the most noticeable characteristic of a region.
The plants also determine the other organisms that can live in an area.
Plants (& animals) in a particular biome have adaptations that enable them to live there.

7. Temperature and Precipitation

8. 1)Tropical Rain Forests
Located in a belt around the Earth near the equator.
Regulate world climate.
Play a vital role in the nitrogen, oxygen, and carbon cycles.

9. Tropical Rain Forests

10. Tropical Rain Forests Always humid and warm
Get 200 to 450 cm of rain a year.
Strong sunlight year round.
Relatively constant temperature year round.

14. Layers of the Rain Forest

15. Threats to Rain Forests
Once covered 20% of the Earth’s surface.
Now cover only 7% of the Earth’s surface.
Every minute of every day, 100 acres of tropical rain forest are destroyed.

16. 2)Temperate Forests

17. Temperate Deciduous Forests
Trees drop their broad, flat leaves each fall
Range of temperatures can be extreme
Growing season only lasts four to six months
Winter temperatures often fall below freezing. This means little water available for plants.

18. Temperate Deciduous Forests
Vegetation also changes with the seasons.
Organic matter decomposes slowly in the winter.
The soil contains more organic matter and nutrients than the soil in a tropical rain forest.

22. 3) Taiga
Northern coniferous forest (trees with cones & needles like pine trees)
Just below the Arctic Circle
Winters are long (6 to 10 months)
Average temperatures just below freezing.
Plant growth is most abundant during the summer because of constant daylight and more precipitation.

23. Taiga

27. Plants of the Taiga
Conifer – tree with needle-like leaves and seeds that develop in cones
The shape of the leaves and waxy coating prevent them from losing too much water.
Cone-like shape prevents snow from building up on branches and causing breakage.

28. Plants of the Taiga
Needles contain substances to make the soil acidic when the needles fall to the ground.
Most plants cannot grow in acidic soil.
Soil forms slowly because of the climate and acidity of the soil.

29. A Comparison

30. 4) Savannas
Parts of Africa, Western India, Northern Australia, South America
Tropical Biome
Dominated by grasses, shrubs, small trees
Have a wet season and dry season

31. Savannas

34. 5) Temperate Grasslands
Large areas of the interior of continents
Moderate rainfall but still too little for trees
Prairies in North America, steppes in Asia, veldt in South Africa, pampas in South America

35. Temperate Grasslands

36. Prairie (North American Grasslands)

37. Steppe (Grasslands in Asia)

38. Veldt (Grasslands in South Africa)

39. Pampas (Grasslands in South America)

40. Plants of Temperate Grasslands
Most fertile soil in the world
Farmland

41. 6) Deserts Widely scattered vegetation Very little rain
In extreme cases, it never rains and there is no vegetation
Temperature changes rapidly during a 24 hour period.
Often located near mountains that block rain clouds.

42. Deserts

43. Deserts

47. 7) Tundra Northern arctic regions Too cold and dry for trees
Permafrost – deeper layers of soil are permanently frozen throughout the year.
Thin topsoil
When the topsoil thaws, the land becomes wet and spongy and is covered in bogs.

48. Tundra