1. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology: Concepts and Connections, Fifth Edition – Campbell, Reece, Taylor, and Simon Lectures by Chris Romero Chapter 34 The Biosphere: An Introduction to Earth's Diverse Environments

2. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings A Mysterious Giant of the Deep Deep-sea submersibles are revealing the diversity of life beneath the ocean – Giant squid – Hydrothermal vent communities Animals, such as tube worms, living on energy produced by chemoautotrophic bacteria Ecology is the scientific study of the interactions of organisms with their environments

7. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Video: Hydrothermal Vent Video: Hydrothermal Vent Video: Tubeworms Video: Tubeworms

8. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.1 Ecologists study how organisms interact with their environment at several levels Organism – Individual organisms interacting with the environment Population – Group of individuals of the same species living in a particular geographic area

9. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Community – All the populations of different species that inhabit a particular area Ecosystem – All the biotic and abiotic components in a certain area Ecological research is conducted in the field as well as in the lab and with models

11. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings THE BIOSPHERE 34.2 The biosphere is the total of all of Earth's ecosystems The biosphere is the global ecosystem – Atmosphere to an altitude of several kilometers – Land down to 3,000 m beneath Earth's surface – Oceans to a depth of several kilometers The biosphere is self-contained and characterized by patchiness

14. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CONNECTION 34.3 Environmental problems reveal the limits of the biosphere No part of the biosphere is untouched by human activities Current awareness of the biosphere's limits stems from past environmental practices – Rachel Carson warned of the effects of pesticides in 1962

16. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.4 Physical and chemical factors influence life in the biosphere Major abiotic factors determine the biosphere's structure and dynamics – Solar energy – Water – Temperature – Wind – Disturbances such as fire, hurricanes

18. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.5 Organisms are adapted to abiotic and biotic factors by natural selection Species exist in a given place because they evolve there or disperse there Unique adaptations that fit a particular environment allow organisms to survive there – Example: pronghorns Organisms vary greatly in their ability to tolerate fluctuations and long-term changes in their environment

20. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.6 Regional climate influences the distribution of biological communities Because of its curvature, Earth receives an uneven distribution of solar energy The tilt of the Earth's axis causes the seasons of the year – Globe's position relative to the sun changes through the year – The tropics experience the least seasonal variation in solar radiation

21. LE 34-6a Low angle of incoming sunlight Sunlight strikes most directly Low angle of incoming sunlight Atmosphere North Pole 60°N 30°N Tropic of Cancer 0° (equator) Tropic of Capricorn 30°S 60°S South Pole

22. LE 34-6b June solstice (Northern Hemisphere tilts toward sun) March equinox (equator faces sun directly) Constant tilt of 23.5° September equinox December solstice (Northern Hemisphere tilts away from sun)

23. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Uneven heating of the Earth sets up patterns of precipitation and prevailing winds – Doldrums are near the equator – Trade winds dominate the tropics – Seasonal climate variation and more moderate temperatures exist in the temperate zones – Prevailing winds are major global air movements

24. LE 34-6c Descending dry air absorbs moisture Trade winds Ascending moist air releases moisture Trade winds Descending dry air absorbs moisture Doldrums Tropics Temperate zone Temperate zone 30° 0° 23.5° 30°

25. LE 34-6d 60°N 30°N 30°S

26. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ocean currents have a profound effect on regional climates – Generally modify climate of nearby land Landforms can also affect local climate Variations in climate determine the character of the world's biomes

27. LE 34-6e 40 miles Death Valley 119° Fresno 104° Paso Robles 93° Bakersfield 106° Burbank 86° San Bernardino 101° Riverside 91° Santa Ana 84° Palm Springs 104° Los Angeles (Airport) 74° Santa Barbara 75° San Diego 75° 70s (°F) 80s 90s 100s 110s Key Pacific Ocean

28. LE 34-6f Pacific Ocean Wind direction Coast Range Sierra Nevada East

29. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings AQUATIC BIOMES 34.7 Oceans occupy most of Earth's surface Abiotic factors influencing the distribution of aquatic biomes – Light – Distance from shore – Availability of nutrients Oceanic zones – Intertidal zone: where land meets ocean

31. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings – Pelagic zone: open ocean Contains phytoplankton and zooplankton – Benthic zone: seafloor – Photic zone: illuminated regions of the pelagic and benthic zones Photosynthesis occurs – Aphotic zone: vast, dark region underlying the photic zone Most extensive part of the biosphere

32. LE 34-7b Intertidal zone Benthic zone (seafloor) Continental shelf 200 m 0 Photic zone 2,500–6,000 m Aphotic zone Pelagic zone

33. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Continental shelf: submerged part of a continent Coral reef: found in warm waters above continental shelf – Biologically very diverse Estuary: area where freshwater stream or river merges with ocean – Among the most productive biomes on Earth

34. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Wetland: area that is transitional between an aquatic and terrestrial ecosystem Aquatic communities are environmentally threatened Video: Clownfish and Anemone Video: Clownfish and Anemone Video: Coral Reef Video: Coral Reef

37. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.8 Freshwater biomes include lakes, ponds, rivers, streams, and wetlands Light has a significant effect on freshwater biomes – All but the most shallow ponds and lakes have photic and aphotic zones Temperature creates stratification of water Availability of nutrients and dissolved oxygen influence organic growth – Nitrogen and phosphorus runoff create algal blooms

38. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Rivers and streams support communities quite different from those of lakes and ponds Freshwater wetlands range from swamps to marshes and bogs – Great ecological and economic value

41. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings TERRESTRIAL BIOMES 34.9 Terrestrial biomes reflect regional variations in climate Many biomes are named for climatic features and predominant vegetation Each biome is also characterized by the organisms adapted to that environment The distribution of biomes depends largely on climate Within each biome there is local variation

42. LE 34-9 30°N Tropic of Cancer Equator Tropic of Capricorn 30°S Tropical forest Savanna Desert Chaparral Temperate grassland Temperate broadleaf forest Coniferous forest Tundra High mountains Polar ice

43. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.10 Tropical forests cluster near the equator Rainfall generally determines the type of vegetation in a tropical forest Tropical rain forests are the most complex of all biomes – Very high diversity – Complex structure – Human impact is of great concern

45. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.11 Savannas are grasslands with scattered trees Savannas are dry and warm – Frequent fires inhibit invasion by trees – Large grazing animals migrate during seasonal droughts

47. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.12 Deserts are defined by their dryness Deserts are the driest terrestrial biomes – Can be hot or cold – Cycles of growth and reproduction are keyed to rainfall – Animals are adapted to drought and extreme temperatures Desertification is a significant environmental problem

49. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.13 Spiny shrubs dominate the chaparral The chaparral is a region of dense, spiny shrubs with tough, evergreen leaves – In midlatitude coastal areas – Cool, rainy winters and dry, hot summers – Vegetation adapted to periodic fires

51. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.14 Temperate grasslands include the North American prairie Temperate grasslands are found where winters are cold – Similar to savannas but mostly treeless – Periodic drought, fires, and grazing inhibit growth of woody plants – Amount of annual rainfall influences height of vegetation

53. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.15 Broadleaf trees dominate temperate forests Temperate broadleaf forests grow throughout midlatitude regions – Need sufficient moisture to support the growth of large trees – Mix of tree species depends on abiotic factors Most original North American broadleaf forests were destroyed by logging, agriculture, and development

55. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.16 Coniferous forests are often dominated by a few species of trees Cone-bearing trees dominate northern coniferous forest, or taiga – Found where there are short, wet summers and long, cold winters Logging is eliminating old-growth coniferous trees

57. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 34.17 Long, bitter-cold winters characterize the tundra Arctic tundra is a treeless biome – Found at the northernmost limits of plant growth and at high altitudes – Characterized by extreme cold, wind, and permafrost – Animals have good insulation that retains heat

59. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings TALKING ABOUT SCIENCE 34.18 Ecologist Ariel Lugo studies tropical forests in Puerto Rico The Luquillo Experimental Forest allows ecologists to study the effects of disruption on tropical forests – Mirrors other tropical forests

61. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Dr. Ariel Lugo tempers his concerns about rain forest organisms with an understanding of the social and economic needs of the people there – Important to integrate all legitimate claims on the forest