1. LIVING IN THE ENVIRONMENT 17 TH MILLER/SPOOLMAN Chapter 5 Biodiversity, Species Interactions, and Population Control

2. Core Case Study: Southern Sea Otters: Are They Back from the Brink of Extinction? Habitat Hunted: early 1900s Partial recovery Why care about sea otters? Ethics Tourism dollars Keystone species

3. Biodiversity, Species Interactions, and Population Control Fig. 5-1a, p. 104 Southern Sea Otter

4. 5-1 How Do Species Interact? The interactions between species in an ecosystem affect: the resource use in an ecosystem and population sizes of the species in an ecosystem.

5. Five types of Interactions Interspecific Competition Predation Parasitism Mutualism Commensalism

6. Five types of Interactions Interspecific Competition Predation Parasitism Mutualism Commensalism

7. Interspecific Competition Species compete for limited resources like Water Food/Nutrients Light Habitat/Space

8. Some Species Evolve Ways to Share Resources Resource partitioning Using only parts of resource Using at different times Using in different ways

9. Resource Partitioning Among Warblers Fig. 5-2, p. 106

10. Specialist Species of Honeycreepers Fig. 5-3, p. 107

11. Five types of Interactions Interspecific Competition Predation Parasitism Mutualism Commensalism

12. Predation Predators may capture prey by 1.Walking 2.Swimming 3.Flying 4.Pursuit and ambush 5.Camouflage 6.Chemical warfare

13. Predator-Prey Relationships Fig. 5-4, p. 107

14. Avoiding Predation Prey may avoid capture by 1.Run, swim, fly 2.Protection: shells, bark, thorns 3.Camouflage 4.Chemical warfare 5.Warning coloration 6.Mimicry 7.Deceptive looks 8.Deceptive behavior

15. Some Ways Prey Species Avoid Their Predators Fig. 5-5, p. 109

16. Fig. 5-5a, p. 109 (a) Span worm

17. Fig. 5-5b, p. 109 (b) Wandering leaf insect

18. Fig. 5-5c, p. 109 (c) Bombardier beetle

19. Fig. 5-5d, p. 109 (d) Foul-tasting monarch butterfly

20. Fig. 5-5e, p. 109 (e) Poison dart frog

21. Fig. 5-5f, p. 109 (f) Viceroy butterfly mimics monarch butterfly

22. Fig. 5-5g, p. 109 (g) Hind wings of Io moth resemble eyes of a much larger animal.

23. Fig. 5-5h, p. 109 (h) When touched, snake caterpillar changes shape to look like head of snake.

24. (d) Foul-tasting monarch butterfly (e) Poison dart frog Stepped Art (h) When touched, snake caterpillar changes shape to look like head of snake. (a) Span worm(b) Wandering leaf insect (c) Bombardier beetle (f) Viceroy butterfly mimics monarch butterfly (g) Hind wings of Io moth resemble eyes of a much larger animal. Fig. 5-5, p. 109

25. Science Focus: Threats to Kelp Forests Kelp forests: biologically diverse marine habitat Major threats to kelp forests 1.Sea urchins 2.Pollution from water run-off 3.Global warming

26. Purple Sea Urchin Fig. 5-A, p. 108

27. Predator and Prey Interactions Can Drive Each Other’s Evolution Intense natural selection pressures between predator and prey populations Coevolution Interact over a long period of time Example - Bats and moths: echolocation of bats and sensitive hearing of moths

28. Coevolution: A Langohrfledermaus Bat Hunting a Moth Fig. 5-6, p. 110

29. Five types of Interactions Interspecific Competition Predation Parasitism Mutualism Commensalism

30. Parasitism Parasitism – species feed off other species or live on or in them Parasite is usually much smaller than the host Parasite rarely kills the host Parasite-host interaction may lead to coevolution

31. Parasitism: Trout with Blood-Sucking Sea Lamprey Fig. 5-7, p. 110

32. Parasitism: Tapeworm in Human Eye

33. Five types of Interactions Interspecific Competition Predation Parasitism Mutualism Commensalism

34. Mutualism Mutualism – both species benefit Nutrition and protection relationship Clownfish and anemone Gut inhabitant mutualism Bacteria in our intestines Not cooperation: it’s mutual exploitation

35. Fig. 5-8, p. 110 Mutualism: Hummingbird and Flower

36. Mutualism: Oxpeckers Clean Rhinoceros; Anemones Protect and Feed Clownfish Fig. 5-9, p. 111

37. Fig. 5-9a, p. 111 (a) Oxpeckers and black rhinoceros

38. Fig. 5-9b, p. 111 (b) Clownfish and sea anemone

39. Five types of Interactions Interspecific Competition Predation Parasitism Mutualism Commensalism

40. One species benefits, one not harmed Bromeliad (air plant) in tree Birds nesting in trees

41. Commensalism: Bromiliad Roots on Tree Trunk Without Harming Tree Fig. 5-10, p. 111

42. What Limits the Growth of Populations? No population can continue to grow indefinitely because of limitations on resources and competition among species for those resources.

43. Most Populations Live Together in Clumps or Patches Population: group of interbreeding individuals of the same species Population distribution 1.Clumping (ex. Flocks of birds) 2.Uniform dispersion 3.Random dispersion

44. Generalized Dispersion Patterns Fig. 5-12, p. 112

45. Most Populations Live Together in Clumps or Patches Why clumping? 1.Species cluster where resources are available 2.Clumps have a better chance of finding resources 3.Protects some animals from predators 4.Packs allow some to get prey

46. Population of Snow Geese Fig. 5-11, p. 112

47. Population Growth and Decline Population size governed by Births Deaths Immigration Emigration Population change = (births + immigration) – (deaths + emigration)

48. Population Growth and Decline Age structure Pre-reproductive age “kids” Reproductive age “adults” Post-reproductive age “elderly” Sizes of each group will drive the growth or decline of population in the future Example: A population with 70% of kids will most likely have a population growth spike as those kids become adults

49. Some Factors Can Limit Population Size Range of tolerance Variations in physical and chemical environment that impact a population’s ability to survive and reproduce Temperature, Rain, Nutrients…

50. Trout Tolerance of Temperature Fig. 5-13, p. 113

51. Lower limit of tolerance Higher limit of tolerance No organisms Few organisms Abundance of organisms Few organisms No organisms Population size Zone of physiological stress Optimum range Zone of physiological stress Zone of intolerance LowTemperatureHigh Zone of intolerance

52. Some Factors Can Limit Population Size Limiting factor principle Too much or too little of any physical or chemical factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance “Population can only grow as much as its scarcest resource!”

53. No Population Can Grow Indefinitely: J-Curves and S-Curves Size of populations controlled by limiting factors: Light Water Space Nutrients Exposure to too many competitors, predators or infectious diseases

54. No Population Can Grow Indefinitely: J-Curves and S-Curves Environmental resistance All factors that act to limit the growth of a population Carrying capacity (K) Maximum population a given habitat can sustain Calculated by looking at the limiting factors

55. No Population Can Grow Indefinitely: J-Curves and S-Curves Exponential growth Starts slowly, then accelerates to carrying capacity when meets environmental resistance Known as “J” curve due to shape No limiting factors yet

56. No Population Can Grow Indefinitely: J-Curves and S-Curves (3) Logistic growth Decreased population growth rate as population size reaches carrying capacity Yellow line = calculated theoretical carrying capacity Green = actual population

57. Logistic Growth of Sheep in Tasmania Fig. 5-15, p. 115

58. Science Focus: Why Do California’s Sea Otters Face an Uncertain Future? Low biotic potential Prey for orcas Cat parasites Thorny-headed worms Toxic algae blooms PCBs and other toxins Oil spills

59. Population Size of Southern Sea Otters Off the Coast of So. California (U.S.) Fig. 5-B, p. 114

60. Case Study: Exploding White-Tailed Deer Population in the U.S. 1900: deer habitat destruction and uncontrolled hunting 1920s–1930s: laws to protect the deer Current population explosion for deer Spread Lyme disease Deer-vehicle accidents Eating garden plants and shrubs Ways to control the deer population

61. Mature Male White-Tailed Deer Fig. 5-16, p. 115

62. When a Population Exceeds Its Habitat’s Carrying Capacity, Its Population Can Crash A population can “briefly” exceed (overshoot) the area’s carrying capacity due to: Reproductive time lag If it greatly overshoots the carrying capacity, the result is: Population crash and Damage may reduce area’s new carrying capacity

63. Exponential Growth, Overshoot, and Population Crash of a Reindeer Fig. 5-17, p. 116

64. 2,000 Population overshoots carrying capacity 1,500 Population crashes 1,000 500 Carrying capacity Number of reindeer 19101920193019401950 0 Year

65. Species Have Different Reproductive Patterns Some species Many, usually small, offspring Little or no parental care Massive deaths of offspring Ex. Insects, bacteria, algae

66. Species Have Different Reproductive Patterns Other species Reproduce later in life Small number of offspring with long life spans Young offspring grow inside mother Long time to maturity Protected by parents, and potentially groups Ex. Humans, Elephants

67. Under Some Circumstances Population Density Affects Population Size Density-dependent population controls Predation Parasitism Infectious disease Competition for resources

68. Several Different Types of Population Change Occur in Nature Stable Irruptive Population surge, followed by crash Cyclic fluctuations, boom-and-bust cycles Top-down population regulation Bottom-up population regulation Irregular

69. Population Cycles for the Snowshoe Hare and Canada Lynx Fig. 5-18, p. 118

70. 160 140 Hare Lynx 100 120 80 60 Population size (thousands) 20 40 1845185518651875188518951905191519251935 0 Year

71. Humans Are Not Exempt from Nature’s Population Controls Ireland Potato crop in 1845 Bubonic plague Fourteenth century AIDS Global epidemic

72. 5-3 How Do Communities and Ecosystems Respond to Changing Environmental Conditions? Concept 5-3 The structure and species composition of communities and ecosystems change in response to changing environmental conditions through a process called ecological succession.

73. Communities and Ecosystems Change over Time: Ecological Succession Natural ecological restoration Primary succession Secondary succession

74. Some Ecosystems Start from Scratch: Primary Succession No soil in a terrestrial system or no bottom sediment in an aquatic system Takes hundreds to thousands of years to build up soils/sediments to provide necessary nutrients Ex. – Bare rock after a glacier retreats

75. Primary Ecological Succession Fig. 5-19, p. 119

76. Balsam fir, paper birch, and white spruce forest community Jack pine, black spruce, and aspen Heath mat Small herbs and shrubs Lichens and mosses Exposed rocks Time

77. Balsam fir, paper birch, and white spruce forest community Jack pine, black spruce, and aspen Heath mat Small herbs and shrubs Lichens and mosses Exposed rocks Stepped Art Fig. 5-19, p. 119

78. Some Ecosystems Do Not Have to Start from Scratch Secondary Succession Some soil remains in a terrestrial system or bottom sediment remains in an aquatic system Ecosystem has been Disturbed Removed Destroyed Ex – old farmland, forest fires

79. Natural Ecological Restoration of Disturbed Land Fig. 5-20, p. 120

80. Mature oak and hickory forest Shrubs and small pine seedlings Young pine forest with developing understory of oak and hickory trees Perennial weeds and grasses Annual weeds Time

81. Annual weeds Mature oak and hickory forest Young pine forest with developing understory of oak and hickory trees Time Shrubs and small pine seedlings Perennial weeds and grasses Stepped Art Fig. 5-20, p. 120

82. Secondary Ecological Succession in Yellowstone Following the 1998 Fire Fig. 5-21, p. 120

83. Some Ecosystems Do Not Have to Start from Scratch: Secondary Succession (2) Primary and secondary succession Tend to increase biodiversity Increase species richness and interactions among species Primary and secondary succession can be interrupted by Fires Hurricanes Clear-cutting of forests Plowing of grasslands Invasion by nonnative species

84. Science Focus: How Do Species Replace One Another in Ecological Succession? Facilitation Inhibition Tolerance

85. Succession Doesn’t Follow a Predictable Path Traditional view Balance of nature and a climax community Current view Ever-changing mosaic of patches of vegetation Mature late-successional ecosystems State of continual disturbance and change

86. Living Systems Are Sustained through Constant Change Inertia, persistence Ability of a living system to survive moderate disturbances Resilience Ability of a living system to be restored through secondary succession after a moderate disturbance Some systems have one property, but not the other: tropical rainforests

87. Three Big Ideas 1.Certain interactions among species affect their use of resources and their population sizes. 2.There are always limits to population growth in nature. 3.Changes in environmental conditions cause communities and ecosystems to gradually alter their species composition and population sizes (ecological succession).