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

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1 MILLER/SPOOLMAN LIVING IN THE ENVIRONMENT 17 TH 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 Southern Sea Otter Fig. 5-1a, p. 104

4 5-1 How Do Species Interact? Concept 5-1 Five types of species interactions competition, predation, parasitism, mutualism, and commensalism affect the resource use and population sizes of the species in an ecosystem.

5 Species Interact in Five Major Ways Interspecific Competition Predation Parasitism Mutualism Commensalism

6 Most Species Compete with One Another for Certain Resources For limited resources Ecological niche for exploiting resources Some niches overlap

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

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

9 Blackburnian Warbler Black-throated Green Warbler Cape May Warbler Bay-breasted Warbler Yellow-rumped Warbler Fig. 5-2, p. 106

10 Blackburnian Warbler Black-throated Green Warbler Cape May Warbler Bay-breasted Warbler Yellow-rumped Warbler Stepped Art Fig. 5-2, p. 106

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

12 Fruit and seed eaters Greater Koa-finch Insect and nectar eaters Kuai Akialaoa Kona Grosbeak Amakihi Akiapolaau Crested Honeycreeper Maui Parrotbill Apapane Unknown finch ancestor Fig. 5-3, p. 107

13 Most Consumer Species Feed on Live Organisms of Other Species (1) Predators may capture prey by 1. Walking 2. Swimming 3. Flying 4. Pursuit and ambush 5. Camouflage 6. Chemical warfare

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

15 Most Consumer Species Feed on Live Organisms of Other Species (2) 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

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

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

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

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

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

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

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

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

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

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

26 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

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

28 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 Bats and moths: echolocation of bats and sensitive hearing of moths

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

30 Some Species Feed off Other Species Parasitism by Living 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 In Some Interactions, Both Species Mutualism Benefit Nutrition and protection relationship Gut inhabitant mutualism Not cooperation: it s mutual exploitation

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

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

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

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

37 In Some Interactions, One Species Benefits and the Other Is Not Harmed Commensalism Epiphytes Birds nesting in trees

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

39 5-2 What Limits the Growth of Populations? Concept 5-2 No population can continue to grow indefinitely because of limitations on resources and because of competition among species for those resources.

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

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

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

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

44 (a) Clumped (elephants) Fig. 5-12a, p. 112

45 (b) Uniform (creosote bush) Fig. 5-12b, p. 112

46 (c) Random (dandelions) Fig. 5-12c, p. 112

47 Populations Can Grow, Shrink, or Remain Stable (1) Population size governed by Births Deaths Immigration Emigration Population change = (births + immigration) (deaths + emigration)

48 Populations Can Grow, Shrink, or Remain Stable (2) Age structure Pre-reproductive age Reproductive age Post-reproductive age

49 Some Factors Can Limit Population Size Range of tolerance Variations in physical and chemical environment 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 Precipitation Nutrients Sunlight, etc

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

51 Population size Lower limit of tolerance Higher limit of tolerance No organisms Few organisms Abundance of organisms Few organisms No organisms Zone of intolerance Zone of physiological stress Optimum range Zone of physiological stress Zone of intolerance Low Temperature High Fig. 5-13, p. 113

52 No Population Can Grow Indefinitely: J-Curves and S-Curves (1) Size of populations controlled by limiting factors: Light Water Space Nutrients Exposure to too many competitors, predators or infectious diseases

53 No Population Can Grow Indefinitely: J-Curves and S-Curves (2) Environmental resistance All factors that act to limit the growth of a population Carrying capacity (K) Maximum population a given habitat can sustain

54 No Population Can Grow Indefinitely: J-Curves and S-Curves (3) Exponential growth Starts slowly, then accelerates to carrying capacity when meets environmental resistance Logistic growth Decreased population growth rate as population size reaches carrying capacity

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

56 Number of sheep (millions) 2.0 Population overshoots carrying capacity 1.5 Carrying capacity Population recovers and stabilizes 1.0 Exponential growth Population runs out of resources and crashes Year Fig. 5-15, p. 115

57 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

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

59 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

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

61 When a Population Exceeds Its Habitat s Carrying Capacity, Its Population Can Crash A population exceeds the area s carrying capacity Reproductive time lag may lead to overshoot Population crash Damage may reduce area s carrying capacity

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

63 Number of reindeer 2,000 Population overshoots carrying capacity 1,500 Population crashes 1, Carrying capacity Year Fig. 5-17, p. 116

64 Species Have Different Reproductive Some species Patterns (1) Many, usually small, offspring Little or no parental care Massive deaths of offspring Insects, bacteria, algae

65 Species Have Different Reproductive Patterns (2) 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 Humans Elephants

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

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

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

69 Population size (thousands) Hare Lynx Year Fig. 5-18, p. 118

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

71 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.

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

73 Some Ecosystems Start from Scratch: Primary Succession No soil in a terrestrial system No bottom sediment in an aquatic system Takes hundreds to thousands of years Need to build up soils/sediments to provide necessary nutrients

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

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

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

77 Some Ecosystems Do Not Have to Start from Scratch: Secondary Succession (1) Some soil remains in a terrestrial system Some bottom sediment remains in an aquatic system Ecosystem has been Disturbed Removed Destroyed

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

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

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

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

82 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

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

84 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

85 Living Systems Are Sustained through Inertia, persistence Constant Change 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

86 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).