1. Sustaining Biodiversity: The Species Approach
Chapter 9

2. 9-1 What Role Do Humans Play in the Premature Extinction of Species?
Concept 9-1A We are degrading and destroying biodiversity in many parts of the world, and these threats are increasing.
Concept 9-1B Species are becoming extinct 100 to 1,000 times faster than they were before modern humans arrived on the earth (the background rate), and by the end of this century, the extinction rate is expected to be 10,000 times the background rate.

3. Human Activities Are Destroying and Degrading Biodiversity
Human activity has disturbed at least half of the earth’s land surface
Fills in wetlands
Converts grasslands and forests to crop fields and urban areas
Degraded aquatic biodiversity

4. SPECIES EXTINCTION Species can become extinct:
Locally: A species is no longer found in an area it once inhabited but is still found elsewhere in the world.
Ecologically: Occurs when so few members of a species are left they no longer play its ecological role.
Globally (biologically): Species is no longer found on the earth.

5. Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up
Conservative estimates of extinction = %
Growth of human population will increase this loss
Rates are higher where there are more endangered species
Tropical forests and coral reefs, wetlands and estuaries—sites of new species—being destroyed

6. HABITAT LOSS, DEGRADATION, AND FRAGMENTATION
Figure 9-10
The greatest threat to a species is the loss, degradation, and fragmentation of where it lives.

7. Number of years until one million species are extinct
Number of species existing
Effects of a 0.1% extinction rate
5 million
5,000 extinct per year
14 million
14,000 extinct per year
50 million
50,000 extinct per year
Figure 9.3
Effects of a 0.1% extinction rate.
100,000 extinct per year
100 million 50
100
150
200
Number of years until one million species are extinct
Fig. 9-3, p. 186

8. Endangered Natural Capital: Species Threatened with Premature Extinction
Fig 9-4

9. Characteristic Examples Low reproductive rate (K-strategist)
Blue whale, giant panda, rhinoceros
Characteristic
Examples
Specialized niche
Blue whale, giant panda, Everglades kite
Narrow distribution
Elephant seal, desert pupfish
Feeds at high trophic level
Bengal tiger, bald eagle, grizzly bear
Fixed migratory patterns
Blue whale, whooping crane, sea turtle
Rare
African violet, some orchids
Figure 9.5
Characteristics of species that are prone to ecological and biological extinction. Question: Which of these characteristics helped lead to the premature extinction of the passenger pigeon within a single human lifetime?
Commercially valuable
Snow leopard, tiger, elephant, rhinoceros, rare plants and birds
Large territories
California condor, grizzly bear, Florida panther
Stepped Art
Fig. 9-5, p. 188

10. Percentage of Various Species Threatened with Premature Extinction
Fig 9-6

11. Science Focus: Estimating Extinction Rates Is Not Easy
Three problems
Hard to document due to length of time
Only 1.8 million species identified
Little known about nature and ecological roles of species identified

12. 9-2 Why Should We Care about Preventing Premature Species Extinction?
Concept 9-2 We should prevent the premature extinction of wild species because of the economic and ecological services they provide and because they have a right to exist regardless of their usefulness to us.

13. Why Should We Care About Biodiversity?
Aesthetic pleasure
Ecological: (environmental monitor, ecological balance – keystone species)
Educational
Historical or cultural
Natural Services: (air and water purification, soil fertility, waste disposal,)
Recreational
Medicine
Agriculture: (biological pest control, food source, commercial product – wood)
Moral or ethics

14. Natural Capital: Nature’s Pharmacy
Fig 9-8

15. Endangered Scarlet Macaw is a Source of Beauty and Pleasure

16. 9-3 How do Humans Accelerate Species Extinction?
Concept 9-3 The greatest threats to any species are (in order) loss or degradation of its habitat, harmful invasive species, human population growth, pollution, climate change, and overexploitation.

17. Loss of Habitat Is the Single Greatest Threat to Species: Remember HIPPCO
Habitat destruction, degradation, and fragmentation
Invasive (nonnative) species
Population and resource use growth
Pollution
Climate change
Overexploitation

18. NATURAL CAPITAL DEGRADATION
Causes of Depletion and Premature Extinction of Wild Species
Underlying Causes
• Population growth
• Rising resource use
• Undervaluing natural capital
• Poverty
Figure 9.10
Underlying and direct causes of depletion and premature extinction of wild species (Concept 9-3). The major direct causes of wildlife depletion and premature extinction are habitat loss, degradation, and fragmentation. This is followed by the deliberate or accidental introduction of harmful invasive (nonnative) species into ecosystems. Question: What are two direct causes that are related to each of the underlying causes?
Direct Causes
• Habitat loss
• Pollution
• Commercial hunting and poaching
• Habitat degradation and fragmentation
• Climate change
• Sale of exotic pets and decorative plants
• Overfishing
• Introduction of nonnative species
• Predator and pest control
Fig. 9-10, p. 193

19. Animation: Humans affect biodiversity
Click for animation

20. Natural Capital Degradation: Reduction in the Ranges of Four Wildlife Species
Fig 9-11

21. Case Study: A Disturbing Message from the Birds (1)
Habitat loss and fragmentation of the birds’ breeding habitats
Forests cleared for farms, lumber plantations, roads, and development
Intentional or accidental introduction of nonnative species
Eat the birds

22. Case Study: A Disturbing Message from the Birds (2)
Seabirds caught and drown in fishing equipment
Migrating birds fly into power lines, communication towers, and skyscrapers
Other threats
Oil spills
Pesticides
Herbicides
Ingestion of toxic lead shotgun pellets

23. Distribution of Bird Species in North America and Latin America
Fig 9-12

24. The Ten Most Threatened Song Birds in the United States
Fig 9-13

25. Some Deliberately Introduced Species Can Disrupt Ecosystems
Most species introductions are beneficial
Food
Shelter
Medicine
Aesthetic enjoyment
Nonnative species may have no natural
Predators
Competitors
Parasites
Pathogens

26. Figure 9.14
Some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.
Fig. 9-14a, p. 199

27. Figure 9.14
Some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.
Fig. 9-14b, p. 199

28. Argentina Fire Ant Accidentally Introduced into Mobile, Alabama, U.S.
Fig 9-11

29. Quagga and Zebra
Mussels in California
Quagga fact sheet

30. INVASIVE SPECIES
Many nonnative species provide us with food, medicine, and other benefits but a a few can wipe out native species, disrupt ecosystems, and cause large economic losses.
Arundo removal in the Santa Clara River Watershed
Click for Aurndo report

31. Negative Impacts of Arundo
• Reduction in the shading of surface water, resulting in increased water
temperatures and decreased dissolved-oxygen content, which has a negative
impact on native wildlife
• Reduction in groundwater availability through rapid transpiration
• Alterations in channel morphology by retaining sediments and constricting
flows
• Increased bank erosion due to the diversion of water around established
stands
• Displacement of riparian habitat through monopolization of soil moisture
• Displacement of riparian habitat due to establishment dense monocultures of
arundo
• Reduction in the food supply (particularly insects) of riparian-dependent
wildlife
• Reduction of wildlife utilization of an infested area
• Increased probability of wildfire occurrences, intensity, and area from
increased fire fuel loads

32. Prevention Is the Best Way to Reduce Threats from Invasive Species
Prevent them from becoming established
Learn the characteristics of the species
Set up research programs
Try to find natural ways to control them

33. Characteristics of Invader Species and Ecosystems Vulnerable to Invading Species
Fig 9-17

34. What Can You Do? Controlling Invasive Species
Fig 9-18

35. Bioaccumulation and Biomagnification
Fig 9-19

36. Confiscated Products Made from Endangered Species36

37. Poaching and smuggling of animals and plants
Illegal Killing, Capturing, and Selling of Wild Species Threatens Biodiversity
Poaching and smuggling of animals and plants
Animal parts
Pets
Plants for landscaping and enjoyment
Prevention: research and education

38. 9-4 How Can We Protect Wild Species from Premature Extinction? (1)
Concept 9-4A We can use existing environmental laws and treaties and work to enact new laws designed to prevent species extinction and protect overall biodiversity.
Concept 9-4B We can help to prevent species extinction by creating and maintaining wildlife refuges, gene banks, botanical gardens, zoos, and aquariums.

39. 9-4 How Can We Protect Wild Species from Premature Extinction? (2)
Concept 9-4C According to the precautionary principle, we should take measures to prevent or reduce harm to the environment and to human health, even if some of the cause-and-effect relationships have not been fully established, scientifically.

40. International Treaties Help to Protect Species
1975: Convention on International Trade in Endangered Species (CITES)
Signed by 172 countries
Click for link to CITES
Convention on Biological Diversity (BCD)
Focuses on ecosystems
Ratified by 190 countries (not the U.S.)
Click for link to BCD

41. SPECIES EXTINCTION
Scientists use measurements and models to estimate extinction rates.
The International Union for the Conservation of Nature and Natural Resources (IUCN) publishes an annual Red List, listing the world’s threatened species.
There are now 47,667 species on the IUCN Red List (2009 data) and 17,291 of them are threatened with extinction, up from 16,118 last year.
IUCN web page
Figure 11-5

42. Case Study: The U.S. Endangered Species Act (1)
Endangered Species Act (ESA): 1973 and later amended in 1982, 1983, and 1985
Identify and protect endangered species in the U.S. and abroad
Hot Spots

43. Case Study: The U.S. Endangered Species Act
Fig 10-27
Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S.

44. Science Focus: Accomplishments of the Endangered Species Act (1)
Species listed only when serious danger of extinction
Takes decades for most species to become endangered or extinct
More than half of the species listed are stable or improving
Budget has been small

45. Science Focus: Accomplishments of the Endangered Species Act (2)
Suggested changes to ESA
Increase the budget
Develop recovery plans more quickly
Establish a core of the endangered organism’s survival habitat
Click for US Fish and Wildlife Service

46. PROTECTING WILD SPECIES: THE SANCTUARY APPROACH
The U.S. has set aside 544 federal refuges for wildlife, but many refuges are suffering from environmental degradation.
Pelican Island was the nation’s first wildlife refuge.

47. We Can Establish Wildlife Refuges and Other Protected Areas
1903: Theodore Roosevelt
Wildlife refuges
Most are wetland sanctuaries
More needed for endangered plants
Could abandoned military lands be used for wildlife habitats?

48. Gene Banks, Botanical Gardens, and Wildlife Farms Can Help Protect Species
Gene or seed banks
Preserve genetic material of endangered plants
Botanical gardens and arboreta
Living plants
Farms to raise organisms for commercial sale

49. Zoos and Aquariums Can Protect Some Species (1)
Techniques for preserving endangered terrestrial species
Egg pulling
Captive breeding
Artificial insemination
Embryo transfer
Use of incubators
Cross-fostering

50. Zoos and Aquariums Can Protect Some Species (2)
Limited space and funds
Critics say these facilities are prisons for the organisms

51. What Can You Do? Protecting Species
Fig 9-24

52. RECONCILIATION ECOLOGY
Reconciliation ecology involves finding ways to share places we dominate with other species.
Replacing monoculture grasses with native species.
Maintaining habitats for insect eating bats can keep down unwanted insects.
Reduction and elimination of pesticides to protect non-target organisms (such as vital insect pollinators).

53. The Precautionary Principle
Species: primary components of biodiversity
Preservation of species
Preservation of ecosystems

54. Animation: Humans affect biodiversity
Click for animation