Chapter 6-Biomes

1. Chapter 6-Biomes

2. Section 6-1: What is a Biome? • Open to p. 153 • Define “biome” • Give at least 3 examples of biomes you are familiar with

3. What is a biome? • Major type of ecosystem with distinctive temperature, rainfall, and organisms • Either terrestrial (land) or aquatic (water) • Many ecosystems within a biome

4. How are Biomes Described? • Refer to p. 153 to describe how biomes are described and why in your notes.

5. How are Biomes Described? • By vegetation • Plants that grow in a certain region are the most noticeable characteristics of that region • Plants in each region have adaptation that allow them to survive there • Size, shape, color • Examples: tundra plants are shorter because not enough water to support a tall plant, desert plants have waxy structures rather than leaves to conserve water • Plants determine what other organisms will live there

6. Biomes and Climate • Climate: weather conditions such as temperature, precipitation, and humidity over a long period of time. • How do you think latitude and altitude affect biomes?

7. Latitude and Altitude • Latitude: distance north or south of the equator • Altitude: height of an object above sea level How does climate change when you increase latitude or altitude? (read paragraph on p. 155)

8. Section 6-2: Forest Biomes • Read the introduction on p. 156 and get inspired to learn about forests!!!!

9. 4 Forest Biomes • Tropical Rain Forests • Temperate Rain Forests • Temperate Deciduous Forests • Taiga

10. Rain Forests • Tropical zones – near equator (constant temps) • long growing season • constant warm temps • 200-450 cm of rain per year • Biome with dense canopy of evergreen, broadleaf trees • Most diverse land biome • Keeps Earth’s climate regulated

11. Rain forest biodiversity • Contains 70 % of all terrestrial (land) species on earth • Covers only 6 % of earth’s land surface • Holds 50% of earth’s land biomass

12. Rainforest Nutrients • Organisms contain the nutrients, not the soil • Refer to p. 157 to explain why

13. Rainforest Structure • Based on many different species of trees • Canopy – top of forest, leafy tops of trees 50-60 m tall, captures 99% of direct sunlight • Under and Lower Canopy – filtered sunlight • Understory • Forest floor – sparse vegetation due to lack of light and nutrients • Rapid decomposition of dead things recycles nutrients quickly back into the trees making soil nutrient poor

14. Rainforest organisms • Trees have wide bases and shallow roots to take advantage of the thin topsoil • Buttresses – ridges at the base of tree trunk • Epiphytes – plants like orchids that live entirely on the tree trunk or limbs • Arboreal organisms – live in the trees, rarely touch the ground

15. Why is there so much diversity in the rainforest? • High plant diversity = high animal diversity • Wide variety of habitats exist at different levels of the forest • Many specialized adaptations

16. Threats to the rainforest • Deforestation – rainforests once covered 10% of earth’s surface, now only 6% • Logged for export, farm land, grazing land, living space • Infertility of soil causes it to only be useful to farmers for a short time and more land must be cleared • Slow regeneration – hundreds to thousands of years

17. Temperate Rain Forests • North America, Australia, and New Zealand • The Pacific Northwest in North America • High precipitation, high humidity, but moderate temperatures • Ocean prevents freezing and high precipitation keeps humid

18. Temperate Deciduous Forests • Read description on p. 162

19. Temperate Deciduous Forests • Forests whose trees lose their leaves in the fall • In temperate zones with well defined seasons • Wide temp range -30 deg C to 30 deg C • 50 – 300 cm precipitation per year • Trees go through growth season and dormant season • Loss of leaves in fall helps tree conserve water in winter

20. Plants of the Deciduous Forest • Species more varied than in coniferous forest • 3 Distinct vegetation layers • Canopy – highest layer, upper branches and leaves of tall trees, captures most of the sunlight • Understory – layer of young trees and small trees – shrubs • Forest floor – mosses, ferns, decaying matter and organisms • Humus – deep rich, layer of topsoil with organic matter (mostly dead leaves)

21. Animals of the Deciduous Forests • Are adapted to the use of forest plants for food and shelter • Squirrels eat nuts and seeds on treetops • Deer eat leaves from trees and shrubs • Most birds are migratory • Cannot survive harsh winters • Some do not migrate and reduce activity to preserve energy in winter

22. Human impact on deciduous forests • Once covered eastern US, Europe, Asia • Deforestation for farms, orchard, and urban development (cities) • Logging for hardwood and fuel • Ecosystem is slow to regenerate when replanted

24. Taiga • Where do you think the taiga biome is located? • What do you think this area looks and feels like?

25. Taiga (pp. 163-164) • Northern coniferous forest just below the Arctic Circle • Plant growth abundant in summer because of nearly constant daylight and more precipitation • Tree trunks look bare and dead, but they look alive when you look up at their green tops

26. Plants of the Taiga • Conifers: needle-like leaves and seeds found in cones • Waxy leaves with low surface area retain moisture • Cones-like shape prevents snow build-up • Acidic leaves dropping on the soil prevent other plants from growing

27. Animals of the Taiga • Lakes and swamps with aquatic organisms attract birds in summer (they migrate south in winter) • Some organisms hibernate by burrowing (mice) • Snowshoe hares avoid predation by shedding fur to change color with the seasons

28. Section 6-3: Grassland, Desert, and Tundra Biomes

29. Savannas • Tropical and sub-tropical grasslands ranging from dry scrublands to wet, open woodland • In Asia and Africa and South America

30. Savanna climate • Short Rainy seasons (3 months in Africa) • Up to 150 cm of rain per year • Most during heavy thunderstorms • Long seasons of drought, so plants are small

31. Savanna vegetation • Must be resistant to drought, fire, and grazing • Runners – long horizontal stems above ground that aid in reproduction – spread quickly • Rhizomes – horizontal roots underground that are protected from fire • Tufts – large clumps of tall, coarse grasses • Trees and shrubs have thorns or sharp leaves to protect from being eaten • Most vegetation grows rapidly but die down to ground in winter

32. Savanna animals • Concentrated around watering holes • Vertical feeding patterns – animals eat vegetation at different heights • Allows for more animals to survive on limited resources • Decreases competition for food • Migrating animals – migrate to water rather than away from temperature • Lions, cheetahs, elephants, giraffe, wildebeest, zebras, antelope, etc.

33. Temperate Grasslands • An ecosystem where there is more water (moderate rainfall) than in the desert but not enough to support a forest • Located in Africa, central Asia, North America, South America, Australia • Begin at the desert edges • America’s Heartland – central US

34. Grassland climate • A little more rain than the desert, enough to enable grasses to grow • Hot, dry summers • In North America, the height of plants increases as you move eastward away from the Rockies because of increasing amounts of precipitation (most rainfall is over the mountains)

35. Grassland organisms • Vegetation = grasses most common • Rainfall = limiting factor • Animals = grazing herbivores, prairie dogs, worms, insects • Predators of N. America = coyotes, foxes, birds of prey, snakes

36. Importance of grassland fires • Sparked by lightning • Occasional grassfires destroy trees and shrubs • Grasses survive because most of their mass is below ground • Fires remove the organisms that compete with grasses for resources

37. Effects of the amount of rainfall • Rainfall determines size of grasses • More rain = taller grasses • Rainy season / dry season • Precipitation increases as you move eastward in the United States • Most vegetation is drought-resistant

38. Adaptations of grassland animals • Speed of grazing herds like the antelope = escape from predators • Nocturnal animals stay in burrow underground during day to avoid heat and predators

39. Chaparral (p. 168) • Temperate shrubland biome • Mediterranean climate: moderately dry, coastal, little to no rain in summer • See p. 169 for map of locations: in US, the HOLLYWOOD sign and the old western movies show chaparral

40. Organisms of the Chaparral • Plants: low-lying, evergreen shrubs that grow in dense patches • Small leathery leaves to retain water • Oils to promote burning to destroy the trees that compete for light and space • Can resprout after fires • Animals: camouflage (quail, lizards, chipmunks, mule dear have brownish-gray color)

41. Threats to the Chaparral • Human development • A lot of sun so people want to live and work in chaparral biomes

42. Deserts • Located at Tropic of cancer and Tropic of capricorn • Often located near mountains which block rainfall so very little rainfall • Very little biomass (plants and animals) • Soils rich in minerals but poor in organic matter (few organisms) • Pavement – exposed when wind blows away top layer of sand – desert floor composed of rock particles and hard baked sand • Extreme temperature changes daily Very diverse: 1 thing in common=the driest places in the world

43. Types of deserts • Cool and hot • Results from differences in altitude and latitude • Cool = Sierra Nevada and Rocky Mountains • Hot = California, Texas, Arizona, New Mexico

44. Desert organisms • Adapted to survive extreme temperatures and lack of water • Jack rabbit – ears release heat • Camel – water storage • Cacti -water retaining leaves, roots barely penetrate the soil (known as succulents)

45. Desert plants • Able to absorb water from deep underground • Small leaves to reduce water loss through transpiration – cactus needles • Succulents – thick water filled tissue – cacti and aloe vera

46. Desert animals • Wide variety of species • Most water obtained from food, not by drinking water • Adaptations to reduce water loss and survive the heat • Nocturnal – active at night when temp is cool • Big ears – release heat

47. The Tundra • Located in northern hemisphere in Alaska, Canada, Greenland, Iceland, Scandinavia, and Russia • Largest biome = 10% of earth’s surface • Smallest variety of organisms than any other biome • Fragile ecosystem due to lack of biodiversity

48. Tundra Climate • Very little precipitation <25 cm per year • Ice and snow • Very cold, usually 10 degrees C or below • Temp is a limiting factor • Permafrost – frozen soil below the active zone – insulated by mosses and grasses – does not soak in water creating bogs and marshes and insect breeding grounds

49. Tundra plants • Summer growing season = 60 days • Mosses, shrubs, grasses, small wildflowers • Shallow roots, low to the warm ground • Trees look more like shrubs, < 1m tall

50. Tundra animals • Most are seasonal migrators i.e. Birds • Few predators • Birds feed on insects, migrating predators feed on birds • Small herbivores but no reptiles or amphibians