6-3 Grasslands, Desert, & Tundra

1. 6-3 Grasslands, Desert, & Tundra Areas with too little precipitation for large trees.

3. Tropical Savanna

5. Tropical Savanna • Africa, west India, north Australia, parts of South America (pampas) • Grasslands and savannas found in the interior of continents, bordering on deserts and temperate forests. • Tropical biome dominated by grasses, shrubs, & small trees • Rain falls during wet season (only time plants can grow) which lasts for only 2-4 months

6. Tropical Savanna • Savannas, tropical grasslands, have very hot summers and cold winters. The temperature is usually between 10 degrees C and 35 degrees C. • The soil in the savanna is generally a reddish color, porous, acidic, and has only a thin layer of the humus (made from the decomposition of plant and animal matter), and allows rapid water drainage. • Large number of herbivores

7. Tropical Savanna • Savannas usually receive between 20 and 50 inches of rain annually. About 7 months of the year are rainy. Around October there are thunderstorms and drying winds, which signals the beginning of the dry season. • Fires are expected around January at the height of the dry season.

8. Tropical Savanna

9. Plants adapted to survive long period without water: plants lose leaves or die to ground • Large horizontal roots • Vertical leaves to reduce water loss • Thorns to prevent being eaten

10. Animals: • Grazing herbivores migrate to follow rain to water holes • Give birth during rainy season (food most abundant) • Graze at different heights

14. Temperate Grasslands

16. Temperate Grasslands • Interior of continents with moderate rainfall, too little for trees • Prairies (N. America), Steppes (Asia), veldt (S. Africa) & pampas (S. America) • Mountains play a role in maintaining grasslands. Grasslands lie east of mountains. • Fires from thunderstorms help maintain grasslands

18. Temperate Grasslands • Plants: grasses & wildflowers. • Shrubs & trees mainly on banks of streams

19. Temperate Grasslands

20. Temperate Grasslands • Plants: • Root systems form dense layers that survive drought and fire

21. Temperate Grasslands • Most fertile soil – summer hot, winter cold. • Plants die back to roots • Low temperatures slow decomposition. Rate of decay slower than rate of addition of new vegetation. Organic matter accumulates in soil • Most grasslands converted to farmland.

22. Temperate Grasslands • Animals: • Herbivores: large flat back teeth for chewing grasses

23. Temperate Grasslands • Animals: • Many animals live in underground burrows to protect them from fire, weather, and predators

24. Temperate Grasslands • Threats: • Farming & overgrazing. Grain crops do not hold soil as well as grasses, erosion occurs. • Grasslands changed to deserts.

29. Chaparral

31. Chaparral

32. Chaparral • Temperate shrubland found in all parts of the world with Mediterranean climate. • Moderately dry, coastal climate in mid lattitudes (30 degrees N & S of equator) • Little or no rain in summer

33. Chaparral • Plants: • Low-lying, evergreen shrubs & small trees growing in dense patches (olive trees, scrub oak) • Herbs: sage & bay

34. Chaparral • Plants have small leathery leaves that retain water. • Leaves contain oil that promote burning • Chaparral plants adapted to fire.

35. Chaparral • Animals: • Camouflage is common adaptation

36. Chaparral • Threats: • Human development. Near ocean, get a lot of sun, mild climate year round = hot property (Los Angeles)

37. Deserts

38. Deserts • Plants: adapt to less than 10 inches of water/year • Adaptations to obtain & save water • Succulents – thick, fleshy stems & leaves that store water

39. Deserts • Plants: • sharp spines keep animals from eating their juicy flesh • Roots are shallow and spread out just under the surface • Many plants drop their leaves during dry periods • Brief growth spurts after a rare rain.

40. Deserts • Animals: • Reptiles – thick, scaly skin prevents water loss • Amphibians – estivate (bury underground & sleep through dry period) • Many are nocturnal

42. Tundra

44. Tundra

45. Tundra

46. Tundra • Location: northern arctic regions • Winters too cold & dry for trees • Deeper layers of soil stay permanently frozen,(permafrost) • Topsoil thin. Low productivity • In summer, topsoil thaws forming moist spongy bogs • Free, non-frozen water scarce (limiting factor)

47. Tundra • Bogs host mosquitoes & black flies, and birds.

48. Tundra • Plants: low diversity • Mosses & lichens cover rocks in summer • Plants have wide shallow roots to anchor in thin soil against icy winds • Grow close to ground to help absorb heat from soil. • Woody plants (willow & birch) have dwarf forms or grow flat.

50. Tundra • Animals: • Migratory birds breed here in summer • Caribou & moose migrate • Lemmings, mice, hares burrow during winter • Some animals change color and fur is well insulated