1. Global Ecology and Conservation Biology43
Global Ecology and Conservation Biology

2. Do Now: How would cutting down trees affect the water cycle?
How does burning fossil fuels affect the carbon cycle?
How does using nitrogen rich fertilizers affect the nitrogen cycle?

3. Human Impacts on the ecosystem
Whenever our actions reduce biodiversity, we reduce the stability of our ecosystem.
Invasive Species
Deforestation
Biological Magnification
Global Warming

4. Invasive species How does invasive species disrupt stability?
Nonnative species enters an ecosystem. Usually happens through human travel
Has no predators to keep in check, population rises
Occupies the niche of other organisms and can lead to the elimination of native species

5. How does deforestation reduce stability?
Humans cut down trees for farming, paper products, logging etc
Trees are habitats for species. Loss of habitat results in loss of species
When deforestation occurs in the rainforest, this is the greatest loss to biodiversity
Deforestation also leads to global warming because there are less trees to absorb atmospheric carbon dioxide.

6. Herring gull eggs 124 ppm Lake trout 4.83 ppm Concentration of PCBs
Figure 43.23
Herring gull eggs 124 ppm
Lake trout 4.83 ppm
Concentration of PCBs
Smelt 1.04 ppm
Figure Biological magnification of PCBs in a Great Lakes food web
Zooplankton ppm
Phytoplankton ppm 6

7. Biological Magnification
Top trophic levels most affected.
Example: PCBs and DDT affected the egg shells of birds, resulting in decline of reduction rates.
Rachel Carson wrote Silent Spring to bring problem to public
Toxins in environment can also have other effects.
Ex: estrogen in birth control causes feminization of fish

8. CO2 concentration (ppm)
Figure 43.26
14.9
390
14.8
380
14.7
14.6
370
Temperature
14.5
360
14.4
CO2 concentration (ppm)
350
14.3
Average global temperature (C)
14.2
14.2
340
14.1
CO2
330
14.0
Figure Increase in atmospheric carbon dioxide concentration at Mauna Loa, Hawaii, and average global temperatures
13.9
320
13.8
310
13.7
300
13.6
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
Year 8

10. Global Warming
Case study: coral bleaching

11. Overview: Psychedelic Treasure
Scientists have named and described 1.8 million species
Biologists estimate 10–100 million species exist on Earth
Tropical forests contain some of the greatest concentrations of species and are being destroyed at an alarming rate
Humans are rapidly pushing many species, including the newly discovered psychedelic rock gecko, toward extinction 11

12. Figure 43.1
Figure 43.1 What will be the fate of this newly described lizard species? 12

13. Figure 43.2
Figure 43.2 Tropical deforestation in Vietnam 13

14. Concept 43.1: Human activities threaten Earth’s biodiversity
Rates of species extinction are difficult to determine under natural conditions
Extinction is a natural process, but the high rate of extinction is responsible for today’s biodiversity crisis
Human activities are threatening Earth’s biodiversity 14

15. Genetic diversity in a vole population
Figure
Genetic diversity in a vole population
Species diversity in a coastal redwood ecosystem
Figure Three levels of biodiversity (step 3)
Community and ecosystem diversity across the landscape of an entire region 15

16. Genetic Diversity
Genetic diversity comprises genetic variation within a population and between populations
Population extinctions reduce genetic diversity, which in turn reduces the adaptive potential of a species 16

17. Species Diversity
Species diversity is the variety of species in an ecosystem or throughout the biosphere
According to the U.S. Endangered Species Act
An endangered species is “in danger of becoming extinct throughout all or a significant portion of its range”
A threatened species is likely to become endangered in the near future 17

18. Extinction may be local or global
Conservation biologists are concerned about species loss because of alarming statistics regarding extinction and biodiversity
Globally, 12% of birds and 21% of mammals are threatened with extinction
Extinction may be local or global 18

19. Philippine eagle Yangtze River dolphin Figure 43.4
Figure 43.4 A hundred heartbeats from extinction 19

20. Philippine eagle Figure 43.4a
Figure 43.4a A hundred heartbeats from extinction (part 1: Philippine eagle)
Philippine eagle 20

21. Yangtze River dolphin Figure 43.4b
Figure 43.4b A hundred heartbeats from extinction (part 2: Yangtze River dolphin)
Yangtze River dolphin 21

22. Ecosystem Diversity
Human activity is reducing ecosystem diversity, the variety of ecosystems in the biosphere
More than 50% of wetlands in the contiguous United States have been drained and converted to agricultural or other use 22

23. The local extinction of one species can have a negative impact on other species in an ecosystem
For example, flying foxes (bats) are important pollinators and seed dispersers in the Pacific Islands 23

24. Figure 43.5
Figure 43.5 The endangered Marianas “flying fox” bat (Pteropus mariannus), an important pollinator 24

25. Biodiversity and Human Welfare
Human biophilia allows us to recognize the value of biodiversity for its own sake
Species diversity brings humans practical benefits 25

26. Benefits of Species and Genetic Diversity
Species related to agricultural crops can have important genetic qualities
For example, plant breeders bred virus-resistant commercial rice by crossing it with a wild population
In the United States, 25% of prescriptions contain substances originally derived from plants
For example, the rosy periwinkle contains alkaloids that inhibit cancer growth 26

27. Rosy periwinkle Figure 43.UN01
Figure 43.UN01 In-text figure, rosy periwinkle, p. 885
Rosy periwinkle 27

28. The loss of species also means loss of unique genes and genetic diversity
The enormous genetic diversity of organisms has potential for great human benefit 28

29. Ecosystem Services
Ecosystem services encompass all the processes through which natural ecosystems help sustain human life
Some examples of ecosystem services
Purification of air and water
Detoxification and decomposition of wastes
Crop pollination, pest control, and soil preservation
Ecosystem services have an estimated value of $33 trillion per year, but are provided for free 29

30. Threats to Biodiversity
Most species loss can be traced to four major threats
Habitat loss
Introduced species
Overharvesting
Global change 30

31. Habitat Loss
Human alteration of habitat is the greatest threat to biodiversity throughout the biosphere
In almost all cases, habitat fragmentation and destruction lead to loss of biodiversity
For example
In Wisconsin, prairie habitat has been reduced by over 99.9%, resulting in the loss of up to 60% of the original plant species 31

32. Figure 43.6
Figure 43.6 Habitat fragmentation in the foothills of Los Angeles 32

33. Introduced Species
Introduced species are those that humans move from native locations to new geographic regions
Without their native predators, parasites, and pathogens, introduced species may spread rapidly
Introduced species that gain a foothold in a new habitat usually disrupt their adopted community 33

34. Humans have deliberately introduced some species with good intentions but disastrous effects
For example, kudzu was intentionally introduced to the southern United States 34

35. Figure 43.7
Figure 43.7 Kudzu, an introduced species, thriving in South Carolina 35

36. Overharvesting
Overharvesting is human harvesting of wild plants or animals at rates exceeding the ability of populations of those species to rebound
Species with restricted habitats or large body size with low reproductive rates are especially vulnerable to overharvesting
For example, elephant populations declined because of harvesting for ivory 36

37. DNA analysis can help conservation biologists identify the source of illegally obtained animal products
For example, DNA from illegally harvested ivory can be used to trace the original population of elephants to within a few hundred kilometers 37

38. Figure 43.8
Figure 43.8 Ecological forensics and elephant poaching 38

39. Overfishing has decimated wild fish populations
For example, the North Atlantic bluefin tuna population decreased by 80% in ten years 39

40. Figure 43.9
Figure 43.9 Overharvesting 40

41. Global Change
Global change includes alterations in climate, atmospheric chemistry, and broad ecological systems
Acid precipitation is rain, snow, sleet, or fog with a pH 5.2
Acid precipitation contains sulfuric acid and nitric acid from the burning of wood and fossil fuels 41

42. Acid precipitation kills fish and other lake-dwelling organisms
Air pollution from one region can result in acid precipitation downwind
For example, industrial pollution in the midwestern United States caused acid precipitation in eastern Canada in the 1960s
Acid precipitation kills fish and other lake-dwelling organisms
Environmental regulations have helped to decrease acid precipitation
For example, sulfur dioxide emissions in the United States decreased 40% between 1993 and 2009 42

43. Figure 43.10
4.8
4.7
4.6
4.5
4.4 pH
4.3
4.2
Figure Changes in the pH of precipitation at Hubbard Brook, New Hampshire
4.1
4.0
1960
’65
’70
’75
’80
’85
’90
’95
2000
’05
’10
Year 43

44. Small-Population Approach
The small-population approach studies processes that can make small populations become extinct 44

45. The Extinction Vortex: Evolutionary Implications of Small Population Size
A small population is prone to inbreeding and genetic drift, which draw it down an extinction vortex
The key factor driving the extinction vortex is loss of the genetic variation necessary to enable evolutionary responses to environmental change
Small populations and low genetic diversity do not always lead to extinction 45

46. Inbreeding, genetic drift
Figure 43.11
Small population
Inbreeding, genetic drift
Lower reproduction, higher mortality
Loss of genetic variability
Figure Processes driving an extinction vortex
Lower individual fitness and population adaptability
Smaller population 46

47. Case Study: The Greater Prairie Chicken and the Extinction Vortex
Populations of the greater prairie chicken in North America were fragmented by agriculture and later found to exhibit decreased fertility
To test the extinction vortex hypothesis, scientists imported genetic variation by transplanting birds from larger populations
The declining population rebounded, confirming that low genetic variation had been causing an extinction vortex 47

48. (a) Population dynamics
Figure 43.12
Results
200
150
Number of male birds
100
Translocation 50
1970
1975
1980
1985
1990
1995
Year
(a) Population dynamics
100
Figure Inquiry: What caused the drastic decline of the Illinois greater prairie chicken population? 90 80 70
Eggs hatched (%) 60 50 40 30
1970–’74
’75–’79
’80–’84
’85–’89
’90
’93–’97
Years
(b) Hatching rate 48

49. (a) Population dynamics
Figure 43.12a
Results
200
150
100
Number of male birds
Translocation 50
Figure 43.12a Inquiry: What caused the drastic decline of the Illinois greater prairie chicken population? (part 1: population dynamics)
1970
1975
1980
1985
1990
1995
Year
(a) Population dynamics 49

50. Results 100 90 80 Eggs hatched (%) 70 60 50 40 30 Years
Figure 43.12b
Results
100 90 80 70 60
Eggs hatched (%) 50 40 30
Figure 43.12b Inquiry: What caused the drastic decline of the Illinois greater prairie chicken population? (part 2: hatching rate)
1970–’74
’75–’79
’80–’84
’85–’89
’90
’93–’97
Years
(b) Hatching rate 50

51. Figure 43.12c
Figure 43.12c Inquiry: What caused the drastic decline of the Illinois greater prairie chicken population? (part 3: photo) 51

52. Minimum Viable Population Size
Minimum viable population (MVP) is the minimum population size at which a species can survive
The MVP depends on factors that affect a population’s chances for survival over a particular time 52

53. Effective Population Size
A meaningful estimate of MVP requires determining the effective population size, which is based on the population’s breeding potential

54. Ne = Nf + Nm Effective population size (Ne) is estimated by 4Nf Nm
where Nf and Nm are the number of females and the number of males, respectively, that breed successfully
Conservation programs attempt to sustain population sizes including a minimum number of reproductively active individuals to retain genetic diversity
4Nf Nm
Nf + Nm
Ne =

55. Case Study: Analysis of Grizzly Bear Populations
One of the first population viability analyses was conducted as part of a long-term study of grizzly bears in Yellowstone National Park
It is estimated that a population of 100 bears would have a 95% chance of surviving about 200 years
The Yellowstone grizzly population is estimated to include about 500 individuals, but the Ne is about 125

56. Figure 43.13
Figure Long-term monitoring of a grizzly bear population 56

57. The Yellowstone grizzly population has low genetic variability compared with other grizzly populations
Introducing individuals from other populations would increase the numbers and genetic variation
Promoting dispersal between fragmented populations is an urgent conservation need

58. Declining-Population Approach
The declining-population approach
Focuses on threatened and endangered populations that show a downward trend, regardless of population size
Emphasizes the environmental factors that caused a population to decline

59. Case Study: Decline of the Red-Cockaded Woodpecker
Red-cockaded woodpeckers require living trees in mature pine forests
These woodpeckers require forests with little undergrowth
Logging, agriculture, and fire suppression have reduced suitable habitat

60. Red-cockaded woodpecker
Figure 43.14
Red-cockaded woodpecker
Figure A habitat requirement of the red-cockaded woodpecker
(a) Forests with low undergrowth
(b) Forests with high, dense undergrowth 60

61. (a) Forests with low undergrowth
Figure 43.14a
Figure 43.14a A habitat requirement of the red-cockaded woodpecker (part 1: low undergrowth)
(a) Forests with low undergrowth 61

62. (b) Forests with high, dense undergrowth
Figure 43.14b
Figure 43.14b A habitat requirement of the red-cockaded woodpecker (part 2: high undergrowth)
(b) Forests with high, dense undergrowth 62

63. Red-cockaded woodpecker
Figure 43.14c
Figure 43.14c A habitat requirement of the red-cockaded woodpecker (part 3: woodpecker)
Red-cockaded woodpecker 63

64. Red-cockaded woodpeckers take months to excavate nesting cavities
In a study where breeding cavities were constructed in restored sites, new breeding groups formed only in sites with constructed cavities
Based on this experiment, a combination of habitat maintenance and excavation of breeding cavities enabled this endangered species to rebound

65. Weighing Conflicting Demands
Conserving species often requires resolving conflicts between habitat needs of endangered species and human demands
For example, in the western United States, habitat preservation for many species is at odds with grazing and resource extraction industries
The ecological role of the target species is an important consideration in conservation

66. Concept 43.3: Landscape and regional conservation help sustain biodiversity
Conservation biology has attempted to sustain the biodiversity of entire communities, ecosystems, and landscapes
Ecosystem management is part of landscape ecology, which seeks to make biodiversity conservation part of land-use planning

67. Landscape Structure and Biodiversity
The structure of a landscape can strongly influence biodiversity

68. Fragmentation and Edges
The boundaries, or edges, between ecosystems are defining features of landscapes
Some species take advantage of edge communities to access resources from both adjacent areas

69. Figure 43.15
Figure Edges between ecosystems 69

70. The Biological Dynamics of Forest Fragments Project in the Amazon examines the effects of fragmentation on biodiversity
Landscapes dominated by fragmented habitats support fewer species due to a loss of species adapted to habitat interiors

71. Figure 43.16
Figure Amazon rain forest fragments created as part of the Biological Dynamics of Forest Fragments Project 71

72. Corridors That Connect Habitat Fragments
A movement corridor is a narrow strip of habitat connecting otherwise isolated patches
Movement corridors promote dispersal and reduce inbreeding
Corridors can also have harmful effects, for example, promoting the spread of disease
In areas of heavy human use, artificial corridors are sometimes constructed

73. Figure 43.17
Figure An artificial corridor 73

74. Establishing Protected Areas
Conservation biologists apply understanding of landscape dynamics in establishing protected areas to slow the loss of biodiversity

75. Preserving Biodiversity Hot Spots
A biodiversity hot spot is a relatively small area with a great concentration of endemic species and many endangered and threatened species
Biodiversity hot spots are good choices for nature reserves, but identifying them is not always easy

76. Designation of hot spots is often biased toward saving vertebrates and plants
Hot spots can change with climate change

77. Earth’s terrestrial ( ) and marine ( ) biodiversity hot spots
Figure 43.18
Equator
Figure Earth’s terrestrial and marine biodiversity hot spots
Earth’s terrestrial ( ) and marine ( ) biodiversity hot spots 77

78. Philosophy of Nature Reserves
Nature reserves are biodiversity islands in a sea of habitat degraded by human activity
Nature reserves must consider disturbances as a functional component of all ecosystems

79. An important question is whether to create numerous small reserves or fewer large reserves
Smaller reserves may be more realistic and may slow the spread of disease between populations
One argument for large reserves is that large, far-ranging animals with low-density populations require extensive habitats
Large reserves also have proportionally smaller perimeters, reducing edge effects

80. Grand Teton National Park
Figure 43.19 50
100
Kilometers
MONTANA
WYOMING
Yellowstone
MONTANA
National Park
IDAHO
Figure Biotic boundaries for grizzly bears in Yellowstone and Grand Teton National Parks
Grand Teton National Park
Snake R.
Biotic boundary for short-term survival; MVP is 50 individuals.
WYOMING
Biotic boundary for long-term survival; MVP is 500 individuals.
IDAHO 80

81. Zoned Reserves
A zoned reserve includes relatively undisturbed areas surrounded by human-modified areas of economic value
The zoned reserve approach creates buffer zones by regulating human activities in areas surrounding the protected core
Zoned reserves are often established as “conservation areas”
Costa Rica has become a world leader in establishing zoned reserves

82. Nicaragua CARIBBEAN SEA Costa Rica National park land Buffer zone
Figure 43.20
Nicaragua
CARIBBEAN SEA
Costa Rica
National park land
Figure Zoned reserves in Costa Rica
Buffer zone
PACIFIC OCEAN 82

83. Many fish populations have collapsed due to modern fishing practices
Some areas in the Fiji islands are closed to fishing, which improves fishing success in nearby areas
The United States has adopted a similar zoned reserve system with the Florida Keys National Marine Sanctuary
Video: Coral Reef

84. Florida Keys National Marine Sanctuary
Figure 43.21
GULF OF MEXICO
FLORIDA
Florida Keys National Marine Sanctuary
50 km
Figure A diver measuring coral in the Florida Keys National Marine Sanctuary 84

85. Figure 43.21a
Figure 43.21a A diver measuring coral in the Florida Keys National Marine Sanctuary (photo) 85

86. Concept 43.4: Earth is changing rapidly as a result of human actions
The locations of reserves today may be unsuitable for their species in the future
Human-caused changes in the environment include
Nutrient enrichment
Accumulation of toxins
Climate change

87. Nutrient Enrichment
Humans transport nutrients from one part of the biosphere to another
Harvest of agricultural crops exports nutrients from the agricultural ecosystem
Agriculture leads to the depletion of nutrients in the soil
Fertilizers add nitrogen and other nutrients to the agricultural ecosystem

88. Critical load is the amount of added nutrient that can be absorbed by plants without damaging ecosystem integrity
Nutrients that exceed the critical load leach into groundwater or run off into aquatic ecosystems
Agricultural runoff and sewage lead to phytoplankton blooms in the Atlantic Ocean
Decomposition of phytoplankton blooms causes “dead zones” due to low oxygen levels

89. Figure 43.22
Figure A phytoplankton bloom arising from nitrogen pollution in the Mississippi basin that leads to a dead zone 89

90. Toxins in the Environment
Humans release many toxic chemicals, including synthetics previously unknown to nature
In some cases, harmful substances persist for long periods in an ecosystem
One reason toxins are harmful is that they become more concentrated in successive trophic levels
Biological magnification concentrates toxins at higher trophic levels, where biomass is lower

91. PCBs and many pesticides such as DDT are subject to biological magnification in ecosystems
Herring gulls of the Great Lakes lay eggs with PCB levels 5,000 times greater than in phytoplankton

92. Herring gull eggs 124 ppm Lake trout 4.83 ppm Concentration of PCBs
Figure 43.23
Herring gull eggs 124 ppm
Lake trout 4.83 ppm
Concentration of PCBs
Smelt 1.04 ppm
Figure Biological magnification of PCBs in a Great Lakes food web
Zooplankton ppm
Phytoplankton ppm 92

93. In the 1960s Rachel Carson brought attention to the biomagnification of DDT in birds in her book Silent Spring
DDT was banned in the United States in 1971
Countries with malaria face a trade-off between killing mosquitoes (malarial vectors) and protecting other species

94. Figure 43.24
Figure Rachel Carson 94

95. Pharmaceutical drugs enter freshwater ecosystems through human and animal waste
Estrogen used in birth control pills can cause feminization of males in some species of fish

96. Sewage treatment plant Lakes and rivers
Figure 43.25
Pharmaceuticals
Farm animals
Humans
Toilet
Manure
Agricultural runoff
Sludge
Farms
Treated effluent
Figure Sources and movements of pharmaceuticals in the environment
Sewage treatment plant
Lakes and rivers 96

97. Greenhouse Gases and Climate Change
One pressing problem caused by human activities is the rising concentration of atmospheric CO2 due to the burning of fossil fuels and deforestation

98. CO2 concentration (ppm)
Figure 43.26
14.9
390
14.8
380
14.7
14.6
370
Temperature
14.5
360
14.4
CO2 concentration (ppm)
350
14.3
Average global temperature (C)
14.2
14.2
340
14.1
CO2
330
14.0
Figure Increase in atmospheric carbon dioxide concentration at Mauna Loa, Hawaii, and average global temperatures
13.9
320
13.8
310
13.7
300
13.6
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
Year 98

99. CO2, water vapor, and other greenhouse gases reflect infrared radiation back toward Earth; this is the greenhouse effect
This effect is important for keeping Earth’s surface at a habitable temperature
Increasing concentration of atmospheric CO2 is linked to increasing global temperature

100. Climatologists can make inferences about prehistoric climates
CO2 levels are inferred from bubbles trapped in glacial ice
Chemical isotope analysis is used to infer past temperature

101. Northern coniferous forests and tundra show the strongest effects of global warming
For example, in 2007 the extent of Arctic sea ice was the smallest on record

102. Range Shifts and Climate Change
Many organisms, especially plants, may not be able to disperse rapidly enough to survive rapid climate change
Researchers can track changes in tree distributions since the last period of glaciation to help infer future changes due to climatic warming
102

103. (b) 4.5C warming over next century
Figure 43.27
Figure Current range and predicted range for the American beech under two climate-change scenarios
(a) Current range
(b) 4.5C warming over next century
(c) 6.5C warming over next century
103

104. Climate Change Solutions
Global warming can be slowed by reducing energy needs and converting to renewable sources of energy
Stabilizing CO2 emissions will require an international effort and changes in personal lifestyles and industrial processes
Reduced deforestation would also decrease greenhouse gas emissions

105. Concept 43.5: The human population is no longer growing exponentially but is still increasing rapidly
Global environmental problems arise from growing consumption and the increasing human population
No population can grow indefinitely, and humans are no exception
105

106. The Global Human Population
The human population increased relatively slowly until about 1650 and then began to grow exponentially
106

107. Human population (billions)
Figure 43.28 7 6 5
Human population (billions) 4 3 2
Figure Human population growth (data as of 2011) 1
8000
4000
3000
2000
1000
1000
2000
BCE
BCE
BCE
BCE
BCE CE CE
107

108. The global population is now more than 7 billion
Though the global population is still growing, the rate of growth began to slow during the 1960s
108

109. Annual percent increase
Figure 43.29
2.2
2.0
1.8
1.6
1.4
2011
Annual percent increase
1.2
Projected data
1.0
0.8
Figure Annual percent increase in the global human population (data as of 2011)
0.6
0.4
0.2
1950
1975
2000
2025
2050
Year
109

110. The growth rates of individual nations vary with their degree of industrialization
Most of the current global population growth is concentrated in developing countries
Human population growth rates can be controlled through family planning, voluntary contraception, and increased access to education for females
110

111. Global Carrying Capacity
How many humans can the biosphere support?
Population ecologists predict a global population of 8.110.6 billion people in 2050
111

112. Estimates of Carrying Capacity
The carrying capacity of Earth for humans is uncertain
The average estimate is 10–15 billion
112

113. Limits on Human Population Size
The ecological footprint concept summarizes the aggregate land and water area needed to sustain the people of a nation
It is one measure of how close we are to the carrying capacity of Earth
Countries vary greatly in footprint size and available ecological capacity
113

114. Energy use (GJ):  300 150–300 50–150 10–50  10 Figure 43.30
Figure Annual per capita energy use around the world
Energy use (GJ):
 300
150–300
50–150
10–50
 10
114

115. Our carrying capacity could potentially be limited by food, space, nonrenewable resources, or buildup of wastes
Unlike other organisms, we can regulate our population growth through social changes
115

116. Concept 43.6: Sustainable development can improve human lives while conserving biodiversity
The concept of sustainability helps ecologists establish long-term conservation priorities
116

117. Sustainable Development
Sustainable development is development that meets the needs of people today without limiting the ability of future generations to meet their needs
To sustain ecosystem processes and slow the loss of biodiversity, connections between life sciences, social sciences, economics, and humanities must be made
117