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

2. Aim: How can we describe global ecology and conservation biology
Aim: How can we describe global ecology and conservation biology? Do Now: How can we describe the difference between species diversity and species density? Homework: Read chapter 43 and complete associated concept questions.

3. 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. 3

4. Figure 43.1
Figure 43.1 What will be the fate of this newly described lizard species? 4

5. Figure 43.2
Figure 43.2 Tropical deforestation in Vietnam 5

6. Conservation biology, which seeks to preserve life, integrates several fields:
Ecology
Evolutionary biology
Molecular biology
Genetics
Physiology 6

7. 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. 7

8. Three Levels of Biodiversity
Biodiversity has three main components:
Genetic diversity
Species diversity
Ecosystem diversity 8

9. Genetic diversity in a vole population
Figure
Genetic diversity in a vole population
Figure Three levels of biodiversity (step 1) 9

10. 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 2) 10

11. 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 11

12. 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. 12

13. 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. 13

14. 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. 14

15. Ecosystem Diversity
Human activity is reducing ecosystem diversity, the variety of ecosystems in the biosphere.
More than 50% of wetlands in the United States have been drained and converted for agricultural or other use.
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 15

16. 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
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. 16

17. 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. 17

18. Aim: How can we describe global ecology and conservation biology
Aim: How can we describe global ecology and conservation biology? Do Now: What are some examples of habitat destruction?

19. Threats to Biodiversity
Most species loss can be traced to four major threats:
Habitat loss
Introduced species
Overharvesting
Global change 19

20. 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 20

21. 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 21

22. 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 22

23. Figure 43.8
Figure 43.8 Ecological forensics and elephant poaching 23

24. Overfishing has decimated wild fish populations.
For example, the North Atlantic bluefin tuna population decreased by 80% in ten years 24

25. Figure 43.9
Figure 43.9 Overharvesting 25

26. 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. 26

27. 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 27

28. Concept 43.2: Population conservation focuses on population size, genetic diversity, and critical habitat
Biologists focusing on conservation at the population and species levels follow two main approaches
The small-population approach
The declining-population approach 28

29. 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.
A meaningful estimate of MVP requires determining the effective population size, which is based on the population’s breeding potential. 29

30. 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 =

31. 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

32. Aim: How can we describe gloabal ecology and conservation biology
Aim: How can we describe gloabal ecology and conservation biology? Do Now: What is global warming? List some ways it can be limited?

33. 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

34. 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

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

36. 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

37. 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

38. Establishing Protected Areas
Conservation biologists apply understanding of landscape dynamics in establishing protected areas to slow the loss of biodiversity
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
Designation of hot spots is often biased toward saving vertebrates and plants
Hot spots can change with climate change

39. 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 39

40. 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

41. 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

42. 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

43. 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 43

44. 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

45. 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

46. 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

47. 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

48. 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

49. 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

50. 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 50

51. 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

52. 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

53. 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 53

54. 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
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

55. 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

56. Aim: How can we describe global ecology and conservation biology
Aim: How can we describe global ecology and conservation biology? Do Now: Describe what an ecological foot print is? Do you have a large or small one? Describe your rationale.

57. 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
The human population increased relatively slowly until about 1650 and then began to grow exponentially
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 57

58. 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 58

59. 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
The carrying capacity of Earth for humans is uncertain
The average estimate is 10–15 billion 59

60. 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 60

61. 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 61

62. 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 62

63. Concept 43.6: Sustainable development can improve human lives while conserving biodiversity
The concept of sustainability helps ecologists establish long-term conservation priorities
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 63

64. Case Study: Sustainable Development in Costa Rica
Costa Rica’s conservation of tropical biodiversity involves partnerships between the government, nongovernmental organizations (NGOs), and private citizens
Human living conditions (infant mortality, life expectancy, literacy rate) in Costa Rica have improved along with ecological conservation 64

65. The Future of the Biosphere
Our lives differ greatly from those of early humans, who hunted and gathered and painted on cave walls

66. (b) A 30,000-year-old ivory carving of a water bird, found in Germany
Figure 43.31
(a) Detail of animals in a 17,000-year-old cave painting, Lascaux, France
(b) A 30,000-year-old ivory carving of a water bird, found in Germany
Figure Biophilia, past and present
(c) Nature lovers on a wildlife-watching expedition
(d) A young biologist holding a songbird 66

67. Our behavior reflects remnants of our ancestral attachment to nature and the diversity of life—the concept of biophilia
Our sense of connection to nature may motivate realignment of our environmental priorities