1. Species diversity
Species Diversity = the number or variety of species in the world or in a particular region
Richness = the number of species
Evenness or relative abundance = extent to which numbers of individuals of different species are equal or skewed
Speciation generates new species and adds to species richness
Extinction reduces species richness

2. Genetic diversity
Encompasses the differences in DNA among individuals within species and populations
The raw material for adaptation to local conditions
Populations with higher genetic diversity can survive
They can cope with environmental change
Populations with low genetic diversity are vulnerable
To environmental change
Disease
Inbreeding depression = genetically similar parents mate and produce inferior offspring

3. Ecosystem diversity
Ecosystem diversity = the number and variety of ecosystems
Also encompasses differing communities and habitats
Rapid vegetation change and varying landscapes within an ecosystem promote higher levels of biodiversity

4. Measuring biodiversity is not easy
Out of the estimated million species on Earth, only million species have been successfully catalogued
Very difficult to identify species
Many remote spots on Earth remain unexplored
Small organisms are easily overlooked
Many species look identical until thoroughly examined
Entomologist Terry Erwin found 163 beetle species specialized on one tree species

5. Biodiversity is unevenly distributed
Living things are distributed unevenly across Earth
Latitudinal gradient = species richness increases towards the equator
Canada has species of breeding birds, while Costa Rica has more than 600 species

6. Latitudinal gradient has many causes
Climate stability, high plant productivity, and no glaciation
Tropical biomes support more species and show more species evenness
Diverse habitats increase species diversity
Human disturbance can increase habitat diversity
But only at the local level

7. Biodiversity provides free ecosystem services
Provides food, shelter, fuel
Purifies air and water, and detoxifies wastes
Stabilizes climate, moderates floods, droughts, wind, temperature
Generates and renews soil fertility and cycles nutrients
Pollinates plants and controls pests and disease
Maintains genetic resources
Provides cultural and aesthetic benefits
Allows us to adapt to change
The annual value of just 17 ecosystem services = $ trillion per year

8. Biodiversity helps maintain ecosystem function
Biodiversity increases the stability and resilience of communities and ecosystems
Decreased biodiversity reduces a natural system’s ability to function and provide services to our society
The loss of a species affects ecosystems differently
If the species can be functionally replaced by others, it may make little difference
Extinction of a keystone species may cause other species to decline or disappear
“To keep every cog and wheel is the first precaution of intelligent tinkering” (Aldo Leopold)

9. Biodiversity enhances food security
Genetic diversity within crops is enormously valuable
Turkey’s wheat crops received $50 billion worth of disease resistance from wild wheat
Wild strains provide disease resistance and have the ability to grow back year after year without being replanted
New potential food crops are waiting to be used
Serendipity berry produces a sweetener 3,000 times sweeter than sugar

10. Some potential new food sources

11. Organisms provide drugs and medicines
Each year pharmaceutical products owing their origin to wild species generate up to $150 billion in sales
The rosy periwinkle produces compounds that treat Hodgkin's disease and leukemia

12. Biodiversity generates economic benefits
People like to experience protected natural areas, creating economic opportunities for residents, particularly in developing countries
Costa Rica: rainforests
Australia: Great Barrier Reef
Belize: reefs, caves, and rainforests
A powerful incentive to preserve natural areas and reduce impacts on the landscape and on native species
But, too many visitors to natural areas can degrade the outdoor experience and disturb wildlife

13. People value and seek out nature
Biophilia = connections that humans subconsciously seek with life
Our affinity for parks and wildlife
Keeping of pets
High value of real estate with views of natural lands
Nature deficit disorder = alienation from the natural environment
May be behind the emotional and physical problems of the young

14. Do we have ethical obligations to other species?
Humans are part of nature and need resources to survive
But, we also have conscious reasoning ability and can control our actions
Our ethics have developed from our intelligence and our ability to make choices
Many people feel that other organisms have intrinsic value and an inherent right to exist

15. Biodiversity losses and species extinction
Extinction = occurs when the last member of a species dies and the species ceases to exist
Extirpation = the disappearance of a particular population from a given area, but not the entire species globally
Can lead to extinction

16. Extinction is a natural process
Paleontologists estimate 99% of all species that ever lived are now extinct
Background rate of extinction = natural extinctions for a variety of reasons
1 extinction per 1 to 10 million species for mammals and marine species
1 species out of 1,000 mammal and marine species would go extinct every 1,000 to 10,000 years

17. What makes a species vulnerable to extinction?
Specialized niche
Low reproductive rate
Blue whales, giant panda, rhinoceros
Feeds at high trophic level
Bengal tiger, bald eagle
Fixed migratory patterns
Blue whale, whooping crane, sea turtles
Commercially valuable
Snow leopard, tigers, elephants, rare birds, orchids
Rare/Narrow Distribution (island species)
Need Large Territory
Condor, Florida panther

18. Earth has experienced five mass extinctions
In the past 440 million years, mass extinctions have eliminated at least 50% of all species
After every mass extinction the biodiversity returned to or exceeded its original state

19. The current mass extinction is human caused
During this Quaternary period, we may lose more than half of all species
Hundreds of human-induced species extinctions, and multitudes of others, teeter on the brink of extinction
The current global extinction rate is 100 to 1,000 times greater than the background rate
This rate will increase tenfold in future decades due to human population growth and resource consumption

20. Human Impacts on Ecosystems
Fragmenting and degrading habitat (stop)
e.g. Tropical forests being cut at a rate of 0.6 to 2% per year
Half of remaining forests lost or degraded in 25 to 83yrs
Simplifying natural ecosystems
Creating monocultures
Using, wasting, or destroying an increasing percentage of earth’s NPP (27% of total)
Strengthening some populations of pest species and disease causing bacteria by causing genetic resistance through overuse of pesticides & antibiotics
Eliminating some key predators
Deliberately or accidentally introducing exotic species
Over harvesting of renewable resources
Interfering with normal cycling and flows of energy in ecosystems

21. Causes of Premature Extinction of Wild Species
Fig p. 231

22. People have hunted species to extinction for millennia
Extinctions followed human arrival on islands and continents

23. Poaching often = Extinction
CITIES Treaty

24. Endangered vs. Threatened
So few left that species could soon become extinct over all or most of its range
Threatened:
Still relatively abundant but b/c of declining numbers is likely to become endangered in the near future
WWF study: 30k Under threat of extinction
34% of world’s fish
25% of world’s amphibians
24% of world’s mammals
20% of world’s reptiles
14% of world’s plant species
12% of world’s bird species

25. Current extinction rates are higher than normal
The Red List = an updated list of species facing high risks of extinctions
23% of mammal species
12% of bird species
% of all other species
Since 1970, 58 fish species, 9 bird species, and 1 mammal species has gone extinct
In the U.S., in the last 500 years, 236 animal and 17 plant species are confirmed extinct
Actual numbers are undoubtedly higher

26. Biodiversity loss is more than extinction
Decreasing numbers are accompanied by smaller species’ geographic ranges
Genetic, ecosystem, and species diversity are being lost.
The Living Planet Index summarizes trends in populations
Between 1970 and 2003, the Index fell by 30%

27. Biodiversity loss has many causes
Reasons for biodiversity losses are multifaceted, complex, and hard to determine
Factors may interact synergistically
Four primary causes of population decline are:
Habitat alteration
Invasive species
Pollution
Overharvesting
Global climate change now is the fifth cause

28. Threats from Nonnative Species
Fig p. 238

29. Invasive species cause biodiversity loss
Introduction of non-native species to new environments
Accidental: zebra mussels
Deliberate: food crops
Island species are especially vulnerable
Invaders have no natural predators, competitors, or parasites
Cost billions of dollars in economic damage

30. Pollution causes biodiversity loss
Harms organisms in many ways
Air pollution degrades forest ecosystems
Water pollution adversely affects fish and amphibians
Agricultural runoff harms terrestrial and aquatic species
The effects of oil and chemical spills on wildlife are dramatic and well known
The damage to wildlife and ecosystems caused by pollution can be severe
But it tends to be less than the damage caused by habitat alteration or invasive species

31. Overharvesting causes biodiversity loss
Vulnerable species are large, few in number, long-lived, and have few young (K-selected species)
The Siberian tiger is hunted without rules and regulations
The early 1990s saw increased poaching because of powerful economic incentives
Many other species affected: Atlantic gray whale, sharks, gorillas
Today the oceans contain only 10% of the large animals they once did

32. Climate change causes biodiversity loss
Emissions of greenhouse gases warms temperatures
Modifies global weather patterns and increases the frequency of extreme weather events
Increases stress on populations and forces organisms to shift their geographic ranges
Most animals and plants will not be able to cope

33. Warming has been the greatest in the Arctic
The polar bear is being considered for the endangered species list

34. Biodiversity loss has a variety of causes

35. Conservation biology responds to biodiversity loss
Conservation biology = devoted to understanding the factors that influence the loss, protection, and restoration of biodiversity
Arose as scientists became alarmed at the degradation of natural systems
An applied and goal-oriented science

36. Conservation scientists work at multiple levels
Conservation biologists integrate evolution and extinction with ecology and environmental systems
Design, test, and implement ways to mitigate human impacts
Conservation geneticists = study genetic attributes of organisms to infer the status of their population
Minimum viable population = how small a population can become before it runs into problems
Metapopulations = a network of subpopulations
Small populations are most vulnerable to extinction and need special attention

37. Preserving Biodiversity
The Species Approach
The Ecosystem Approach
Goal
Protect species from
premature extinction
Strategies
Identify endangered species
Protect their critical habitats
Tactics
Legally protect endangered species
Manage habitat
Propagate endangered species in captivity
Reintroduce species into suitable habitats
Protect populations of
species in their natural
habitats
Strategy
Preserve sufficient areas
of habitats in different
biomes and aquatic
systems
Protect habitat areas through private purchase or government action
Eliminate or reduce populations of alien species from protected areas
Manage protected areas to sustain native species
Restore degraded ecosystems
Fig. 7-2, pg. 136
PRESERVE “HOT SPOTS”

38. Protecting Wild Species: The Sanctuary Approach
Wildlife refuges and protected areas
Gene banks, botanical gardens, and farms
Zoos and Aquariums

39. Protecting biodiversity
Captive breeding – individuals are bred and raised with the intent of reintroducing them into the wild
Zoos and botanical gardens
Some reintroductions are controversial
Ranchers opposed the reintroduction of wolves to Yellowstone National Park
Some habitat is so fragmented, a species cannot survive 39

40. Protecting biodiversity
Cloning – a technique to create more individuals and save species from extinction
Most biologists agree that these efforts are not adequate to recreate the lost biodiversity
Ample habitat and protection in the wild are needed to save species

41. Umbrella species
Conservation biologists use particular species as tools to conserve communities and ecosystems
Protecting the habitat of these umbrella species helps protect less-charismatic animals that would not have generated public interest
Flagship species – large and charismatic species used as spearheads for biodiversity conservation
The World Wildlife Fund’s panda bear
Some organizations are moving beyond the single species approach to focus on whole landscapes 41

42. Should conservation focus on endangered species?
Endangered Species Act (1973) (ESA) = forbids the government and private citizens from taking actions that destroy endangered species or their habitats
To prevent extinction
Stabilize declining populations
Enable populations to recover
As of 2007, the U.S. had 1,312 species listed as endangered or threatened

43. US Endangered Species Act (1973—Nixon!)
Provides a program for the conservation of threatened and endangered plants and animals and the habitats in which they are found
Dept of Interior maintains the list of 632 endangered species (over 50% plants) and 190 threatened species
Anyone can petition the US F&WS to add a species to the list (if it is in danger of extinction in all or most of its range)
Can be listed b/c of habitat destruction, overexploitation, disease/predation, inadequacy of existing regulations, any human threat to its continued existence
Law prohibits any action (either administrative or “real”) that results in the “taking” of a listed species OR ADVERSELY AFFECTS HABITAT
Illegal to take, possess, sell, transport listed sp.
Recovery Plan is written for each species
Provides for acquire land that preserves these species

44. The ESA is controversial
Many Americans support protection of endangered species
Opponents feel that the ESA values endangered organisms more than the livelihood of people
Private land use will be restricted if an endangered species is present
“Shoot, shovel, and shut up” = landowners conceal the presence of endangered species on their land
But, the ESA has stopped few development projects
Habitat conservation plans and safe harbor agreements = landowners can harm species if they improve habitat for the species in other places 44

45. Despite opposition, the ESA has had successes
Peregrine falcons, brown pelicans, bald eagles, and others have recovered and are no longer listed
Intensive management has stabilized other species
The red-cockaded woodpecker
40% of declining populations are now stable
These successes occur despite underfunding of the U.S. Fish and Wildlife Service and the National Marine Fisheries Service
In recent years, political forces have attempted to weaken the ESA

46. The Lacey Act
Overview. This Act authorizes the Secretary of the Interior to adopt measures to aid in restoring game and other birds in parts of the U.S. where they have become scarce or extinct and to regulate the introduction of birds and animals in areas where they had not existed. All sections but one of the original 1900 Act have been repealed and either restated in or reenacted by other code provisions. This is a summary of the one remaining section of the original Lacey Act.
Game and Wild Bird Preservation. The purposes of the Act are to aid in the restoration of game and other wild birds in parts of the U.S. where they have become scarce or extinct and to regulate the introduction of American or foreign birds or animals in localities where they have not previously existed. The duties and powers of the Department of the Interior include the preservation, distribution, introduction and restoration of game and other wild birds.

47. Other countries have their own version of the ESA
Species at Risk Act (2002) = Canada’s endangered species law
Stresses cooperation between landowners and provincial governments
Criticized as being too weak
Other nations’ laws are not enforced
The Wildlife Conservation Society has to help pay for Russians to enforce their own anti-poaching laws

48. International conservation efforts
UN Convention on International Trade in Endangered Species of Wild Fauna and Flora (1973) (CITES) – protects endangered species by banning international transport of their body parts
Convention on Biological Diversity (1992) –
Seeks to conserve biodiversity
Use biodiversity in a sustainable manner
Ensure the fair distribution of biodiversity’s benefits
By 2007, 188 nations had signed on
Iraq, Somalia, the Vatican, and the U.S. did not join 48

49. Habitat alteration causes biodiversity loss
The greatest cause of biodiversity loss
Farming simplifies communities
Grazing modifies the grassland structure and species composition
Clearing forests removes resources organisms need
Hydroelectric dams turn rivers into reservoirs upstream
Urbanization and suburban sprawl reduce natural communities
A few species (i.e., pigeons, rats) benefit from changing habitats

50. Habitat alteration has occurred in every biome
Particularly in tropical rainforests, savannas, and tropical dry forests

51. Island biogeography
Equilibrium theory of island biogeography = explains how species come to be distributed among oceanic islands
Also applies to “habitat islands” – patches of one habitat type isolated within a “sea” of others
Explains how the number of species on an island results from an equilibrium between immigration and extirpation
Predicts an island’s species richness based on the island’s size and distance from the mainland

52. Species richness results from island size and distance
Fewer species colonize an island far from the mainland
Large islands have higher immigration rates
Large islands have lower extinction rates

53. Island Biogeography

54. Small “islands” of forest rapidly lose species
Forests are fragmented by roads and logging
Small forest fragments lose diversity fastest
Starting with large species
Fragmentation is one of the prime threats to biodiversity

55. The species-area curve
Large islands contain more species than small islands
They are easier to find and have lower extinction rates
They possess more habitats

56. Biodiversity hotspots
Biodiversity hotspots – prioritizes regions most important globally for biodiversity
Support a great number of endemic species = species found nowhere else in the world
The area must have at least endemic plant species (0.5% of the world total)
It must have lost 70% of its habitat due to human impact 56

57. There are 34 global biodiversity hotspots
2.3% of the planet’s land surface contains 50% of the world’s plant species and 42% of all terrestrial vertebrate species

58. Community- based conservation
Protecting habitats makes good sense, but this affects people living in and near these areas
Community-based conservation = conservation biologists actively engage local people in protecting land and wildlife
Protecting land deprives people access to resources
But, it can guarantee that these resources will not be used up or sold to foreign corporations and can instead be sustainably managed
Many projects have succeeded
But, others have not, due mainly to funding problems 58

59. Innovative economic strategies
Debt-for-nature swap = a conservation organization pays off a portion of a developing country’s international debt
In exchange for a promise by the country to set aside reserves
Fund environmental education, and
Better manage protected areas
Conservation concession = conservation organizations pay nations to conserve, and not sell, resources 59

60. Conclusion Loss of biodiversity will result in a mass extinction
Primary causes of biodiversity loss are:
Habitat alteration, invasive species, pollution, overharvesting of biotic resources, and climate change
Human society cannot function without biodiversity’s benefits
Science can help save species, preserve habitats, restore populations, and keep natural ecosystems intact 60