1. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell & Jane Reece Lectures by Chris Romero Chapter 50 An Introduction to Ecology & the Biosphere

2. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Overview: The Scope of Ecology Ecology- study of interactions b/w organisms & environ These interactions determine distribution of organisms & their abundance Ecology reveals the richness of the biosphere

3. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

4. Concept 50.1: Ecology is the study of interactions b/w organisms & the environment Ecology has a long history as a descriptive science It is also a rigorous experimental science

5. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecology & Evolutionary Biology Events that occur in ecological time affect life on the scale of evolutionary time

6. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Organisms & the Environment The environment of any organism includes: – Abiotic- nonliving – Biotic- living – All organisms part of the indiv’s environment are collectively called the biota Environmental components affect the distribution & abundance of organisms

7. LE 50-2 Kangaroos/km 2 > 20 10–20 5–10 1–5 0.1–1 < 0.1 Limits of distribution Tasmania

8. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecologists use observations & experiments to test explanations for the distribution & abundance of spp

9. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Subfields of Ecology Organismal ecology- how an organism’s structure, physiology, & (for animals) behavior meet environmental challenges

10. LE 50-3a Organismal ecology

11. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings pop ecology- factors affecting how many indiv’s of a spp live in an area

12. LE 50-3b pop ecology

13. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Community ecology- deals w/ interacting spp in a community

14. LE 50-3c Community ecology

15. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecosystem ecology- emphasizes energy flow & chemical cycling for biotic & abiotic factors

16. LE 50-3d Ecosystem ecology

17. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Landscape ecology- arrays of ecosystems & how they are arranged in a geographic region

18. LE 50-3e Landscape ecology

19. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The biosphere is the global ecosystem, the sum of all the planet’s ecosystems

20. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecology & Environmental Issues Ecology provides the scientific understanding underlying environmental issues Rachel Carson is credited w/ starting the modern environmental mvmt

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22. Most ecologists follow the precautionary principle regarding environmental issues It states that humans need to be concerned w/ how their actions affect the environment

23. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 50.2: Interactions b/w organisms & the environment limit the distribution of spp Ecologists have long recognized global & regional patterns of distribution of organisms within the biosphere Many naturalists began to identify broad patterns of distribution by naming biogeographic realms

24. LE 50-5 Tropic of Cancer (23.5°N) Equator (23.5°S) Tropic of Capricorn Neotropical Ethiopian Australian Oriental Nearctic Palearctic

25. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Biogeography is a good starting point for understanding what limits geographic distribution of spp

26. LE 50-6 Dispersal limits distribution? spp absent b/c Behavior limits distribution? Area inaccessible or insufficient time Yes No Yes No Biotic factors (other spp) limit distribution? Habitat selection Abiotic factors limit distribution? Predation, parasitism, competition, disease Yes No Chemical factors Water Oxygen Salinity pH Soil nutrients, etc. Physical factors Tm Light Soil structure Fire Moisture, etc.

27. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Dispersal & Distribution Dispersal- mvmt of indiv’s away from centers of high pop density or from their area of origin Dispersal contributes to global distribution of organisms

28. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Natural Range Expansions Natural range expansions show the influence of dispersal on distribution

29. LE 50-7 New areas occupied Year 1996 1989 1974

30. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings spp Transplants spp transplants include organisms that are intentionally or accidentally relocated from their original distribution spp transplants can disrupt the communities or ecosystems to which they have been introduced

31. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Behavior & Habitat Selection Some organisms do not occupy all of their potential range spp distribution may be limited by habitat selection behavior

32. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Biotic Factors Biotic factors that affect the distribution of organisms: – Interactions w/ other spp – Predation – Competition

33. LE 50-8 August 1982 Sea urchin August 1983 February 1983 February 1984 Both limpets & urchins removed Limpet 100 80 60 40 20 0 Only urchins removed Only limpets removed Control (both urchins & limpets present) Seaweed cover (%)

34. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Abiotic Factors Abiotic factors affecting distribution of organisms: – Tm – Water – Sunlight – Wind – Rocks & soil

35. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Tm Environmental Tm is an important factor in distribution of organisms b/c of its effects on biological processes

36. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Water Water availability in habitats is another important factor in spp distribution

37. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Sunlight Light intensity & quality affects photosynthesis Light is also important to development & behavior of organisms sensitive to photoperiod

38. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Wind Wind amplifies effects of Tm by increasing heat loss from evaporation & convection Wind can change morphology of plants

39. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

40. Rocks & Soil Many chara’s of soil limit distribution of plants & so animals that eat them: – Physical structure – pH – Mineral composition

41. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Climate 4 major abiotic components of climate: Tm, water, sunlight, & wind Climate is the prevailing weather in an area Macroclimate- patterns on the global, regional, & local level Microclimate- fine patterns, such as those encountered by the community of organisms underneath a fallen log

42. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Global Climate Patterns Global climate patterns are determined largely by solar energy & the planet’s mvmt in space

43. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Sunlight intensity plays a major part in determining the Earth’s climate patterns

44. LE 50-10a North Pole 60°N Low angle of incoming sunlight Sunlight directly overhead at equinoxes Tropic of Cancer 60°S South Pole 30°N Atmosphere 30°S Tropic of Capricorn 0° (equator)

45. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Seasonal variations of light & Tm increase steadily toward the poles

46. LE 50-10b June solstice: Northern Hemisphere tilts toward sun; summer begins in Northern Hemisphere; winter begins in Southern Hemisphere. 30°N 30°S 0° (equator) 60°N Constant tilt of 23.5° September equinox: Equator faces sun directly; neither pole tilts toward sun; all regions on Earth experience 12 hours of daylight & 12 hours of darkness. December solstice: Northern Hemisphere tilts away from sun; winter begins in Northern Hemisphere; summer begins in Southern Hemisphere. March equinox: Equator faces sun directly; neither pole tilts toward sun; all regions on Earth experience 12 hours of daylight & 12 hours of darkness.

47. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Global air circulation & wind patterns play major roles in determining climate patterns

48. LE 50-10c 30°N 30°S 0° (equator) 60°N Descending dry air absorbs moisture 60°S Ascending moist air releases moisture Descending dry air absorbs moisture Tropics Arid zone Arid zone 0° 30° 23.5° 30° 23.5°

49. LE 50-10d 30°N 30°S 0° (equator) 60°N 60°S Arctic Circle Antarctic Circle Westerlies Northeast trades Doldrums Westerlies Southeast trades

50. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Regional, Local, & Seasonal Effects on Climate Various features of the landscape contribute to local variations in climate Seasonal variation also influences climate

51. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Bodies of Water Oceans & their currents & large lakes moderate the climate of nearby terrestrial environments

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53. Mt’s have a significant effect on – amt of sun reaching an area – Local Tm – Rainfall Mountains

54. LE 50-12 Pacific Ocean Wind direction Coast Range Sierra Nevada East

55. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Seasonality The angle of the sun leads to many seasonal changes in local environments Lakes are sensitive to seasonal Tm change & experience seasonal turnover

56. LE 50-13 Winter O 2 (mg/L) 12 Lake depth (m) 24 16 8 840 O 2 concentration High (>8 mg/L) Medium (4–8 mg/L) Low (<4 mg/L) O 2 (mg/L) 12 Lake depth (m) 24 16 8 840 O 2 (mg/L) 12 Lake depth (m) 24 16 8 840 O 2 (mg/L) 12 Lake depth (m) 24 16 8 840 Autumn Summer Spring Thermocline 4°C 5° 6° 8° 18° 20° 22° 4°C 4° 4°C 4° 4°C 4° 2° 0° 4°

57. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Microclimate Microclimate- determined by fine-scale differences in abiotic factors

58. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Long-Term Climate Change One way to predict future global climate change is to study previous changes

59. LE 50-14 4.5°C warming over next century 6.5°C warming over next century Current range Predicted range Overlap

60. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 50.3: Abiotic & biotic factors influence the structure & dynamics of aquatic biomes Varying combinations of biotic & abiotic factors determine the nature of biomes Biomes- major ecological associations that occupy broad geographic regions of land or water

61. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Aquatic biomes- lgst part of the biosphere in terms of area They can contain fresh water or salt water Oceans cover about 75% of Earth’s surface & have an enormous impact on the biosphere

62. LE 50-15 Continental shelf Tropic of Capricorn 30°S Tropic of Cancer Equator 30°N Lakes Coral reefs Key Rivers Oceanic pelagic zone Estuaries Intertidal zone Abyssal zone (below oceanic pelagic zone)

63. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Many aquatic biomes are stratified into zones or layers defined by light penetration, Tm, & depth

64. LE 50-16a Zonation in a lake Benthic zone Pelagic zone Aphotic zone Photic zone Littoral zone Limnetic zone

65. LE 50-16b Marine zonation Benthic zone Pelagic zone Aphotic zone Photic zone Oceanic zone Neritic zone Intertidal zone Continental shelf 0 200 m 2,500–6,000 m Abyssal zone (deepest regions of ocean floor)

66. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Major aquatic biomes: – Lakes – Wetlands – Streams & rivers – Estuaries – Intertidal zones – Oceanic pelagic biome – Coral reefs – Marine benthic zone

67. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

77. Video: Hydrothermal Vent Video: Hydrothermal Vent Video: Coral Reef Video: Coral Reef Video: Flapping Geese Video: Flapping Geese Video: Tubeworms Video: Tubeworms Video: Shark Eating a Seal Video: Shark Eating a Seal Video: Clownfish & Anemone Video: Clownfish & Anemone

78. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 50.4: Climate largely determines the distribution & structure of terrestrial biomes Climate is very impt in determining why terrestrial biomes are found in certain areas

79. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Climate & Terrestrial Biomes Climate has a great impact on the distribution of organisms, as seen on a climograph

80. LE 50-18 Temperate grassland Tropical forest Desert Temperate broadleaf forest Coniferous forest Arctic & alpine tundra Annual mean precipitation (cm) Annual mean Tm (°C) 400 300 200 100 30 15 0 –15

81. LE 50-19 Temperate grassland Tropic of Cancer 30°N Tropic of Capricorn 30°S Equator Tropical forest Desert Savanna Key Chaparral Coniferous forest Temperate broadleaf forest Tundra High mountains Polar ice

82. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings General Features of Terrestrial Biomes Terrestrial biomes- named for major physical or climatic factors & for vegetation Stratification- key feature of terrestrial biomes Terrestrial biomes usually grade into each other, w/o sharp boundaries Ecotone- area of intergradation, may be wide or narrow

83. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Major terrestrial biomes: – Tropical forest – Desert – Savanna – Chaparral – Temperate grassland – Coniferous forest – Temperate broadleaf forest – Tundra

84. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

92. Video: Swans Taking Flight Video: Swans Taking Flight