Conservation Biology and Restoration Ecology

1
Chapter 55

• Conservation Biology and Restoration Ecology

2
The Biodiversity Crisis

• Conservation biology integrates the following
  fields to conserve biological diversity at all
  levels
• Ecology
• Evolutionary biology
• Physiology
• Molecular biology
• Genetics
• Behavioral ecology

3

• Restoration ecology applies ecological principles
• in an effort to return degraded ecosystems to
  conditions as similar as possible to their
  natural state

4

• Tropical forests
• contain some of the greatest concentrations of
  species
• are being destroyed at an alarming rate

5

• Throughout the biosphere, human activities
• are altering ecosystem processes on which we and
  other species depend

6

• Concept 55.1 Human activities threaten Earths
  biodiversity
• Rates of species extinction
• are difficult to determine under natural
  conditions because of immigration/emigration.
• The current rate of species extinction is high
• and is largely a result of ecosystem degradation
  by humans
• Humans are threatening Earths biodiversity Due
  to human activity.

7
The Three Levels of Biodiversity

• Biodiversity has three main components
• Genetic diversity
• Species diversity
• Ecosystem diversity

8
Genetic Diversity

• Genetic diversity comprises
• the genetic variation within a population
• the genetic variation between populations
• Genetics create a variation of species in a
  population. This may help you adapt to certain
  conditions. Disease resistance is also due to
  genetic variation.

9
Species Diversity

• Species diversity
• is the variety of species in an ecosystem or
  throughout the biosphere

10

• An endangered species
• is one that is in danger of becoming extinct
  throughout its range. This species is a species
  in danger of becoming extinct.
• Threatened species
• are those that are considered likely to become
  endangered in the foreseeable future

11

• Conservation biologists are concerned about
  species loss
• because of a number of alarming statistics
  regarding extinction and biodiversity

12

• Harvard biologist E. O. Wilson has identified the
  Hundred Heartbeat Club
• species that number fewer than 100 individuals
  and are only that many heartbeats from extinction

12 of known 10,000 bird species 24 of 5,000
known species of mammals are going extinct.
13
Ecosystem Diversity

• Ecosystem diversity
• identifies the variety of ecosystems in the
  biosphere
• is being affected by human activity

14
Biodiversity and Human Welfare

• Human biophilia
• allows us to recognize the value of biodiversity
  for its own sake
• This is our connection to nature. This is
  something within us that wants us to care and
  appreciate nature.
• Species diversity
• brings humans many practical benefits

15
Benefits of Species and Genetic Diversity

• Many pharmaceuticals
• contain substances originally derived from
  plants. Rosey Periwinkle. This plant contains
  alkaloids.

now 25 of all tropical plants may be gone in
next 30 years 14 of vascular plants endangered
16

• The loss of species
• also means the loss of genes and genetic
  diversity
• The enormous genetic diversity of organisms on
  Earth
• has the potential for great human benefit

17

• Biodiversity is crucial natural resource,
  species that are threatened could provide crops,
  fibers, medicines for human use
• Of top 150 drugs in U.S., 118 based on natural
  sources 74 on plants, 18 on fungi,5 on
  bacteria, 3 on one vertebrate (snake) venom
• 80 human population depends on traditional
  medicine 85 of traditional medicine involves
  use of plant extracts

18

• Human history have used 7,000 plant species for
  food
• but, 70,000 plants have edible parts
• currently 82 plant species contribute to 90 of
  food plants
• about 15 species provide bulk of calories
  consumed by humans
• Does this leave us vulnerable?
• What if there is a change in climate?

19

• Last ice age (about 20,000 years ago) much of
  Europe and N. America covered by mile-thick ice
• Global climate has been relatively stable since
  agriculture was invented about 10,000 years ago
• life has played a role in buffering climate
  change
• How?
• ecosystems can help prevent overheating of Earth
  by removing greenhouse CO2 from atmosphere

20
The decomposers

• 130 billion tons of waste processed each year
• 30 from human activities
• Conversion of complex organic molecules to simple
  one
• includes industrial wastes like detergents,
  pesticides, oil, acids, paper
• Soils return simple inorganic molecules to plants
  as nutrients
• depends on activity of bacteria, fungi, algae,
  worms, crustaceans, insects
• bacteria fix nitrogen, fungi make nutrients
  available, worms are mechanical blenders

21

• Under square metre of pasture soil is inhabited
  by 50,000 earthworms, 50,000 insects mites, 12
  million roundworms
• What about soil microorganisms?
• teaspoon of soil contains about 30,000 protozoa,
  500,000 algae, 400,000 fungi, billions of
  individual bacteria
• They dont need us but we need them

22
Ecosystem Services

• Ecosystem services encompass all the processes
• through which natural ecosystems and the species
  they contain help sustain human life on Earth

23

• Ecosystem services include
• Purification of air and water
• Detoxification and decomposition of wastes
• Cycling of nutrients
• Moderation of weather extremes
• And many others

24
Four Major Threats to Biodiversity

• Most species loss can be traced to four major
  threats
• Habitat destruction
• Introduced species
• Overexploitation
• Disruption of interaction networks

25
Habitat Destruction

• Human alteration of habitat
• is the single greatest threat to biodiversity
  throughout the biosphere
• Massive destruction of habitat
• has been brought about by many types of human
  activity. Like
• Clear cutting
• Population
• Mining ? agriculture

26

• Many natural landscapes have been broken up
• fragmenting habitat into small patches Could be
  natural or manmade.

27

• In almost all cases
• habitat fragmentation and destruction leads to
  loss of biodiversity

28
Introduced Species

• Introduced species
• are those that humans move from the species
  native locations to new geographic regions

29

• Introduced species that gain a foothold in a new
  habitat
• usually disrupt their adopted community

30
Overexploitation

• Overexploitation refers generally to the human
  harvesting of wild plants or animals.
• at rates exceeding the ability of populations of
  those species to rebound (hunting animals,
  logging for furniture)

31

• The fishing industry
• has caused significant reduction in populations
  of certain game fish, codfish.

32
Disruption of Interaction Networks

• The extermination of keystone species by humans
• can lead to major changes in the structure of
  communities. This bat is a keystone species
  because its lack of presence has resulted in a
  decrease of plants, due to lack of pollination.

33

• Concept 55.2 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

34
Small-Population Approach

• Conservation biologists who adopt the
  small-population approach
• study the processes that can cause very small
  populations finally to become extinct

35
The Extinction Vortex

• A small population is prone to positive-feedback
  loops
• that draw the population down an extinction vortex

36

• The key factor driving the extinction vortex
• is the loss of the genetic variation necessary to
  enable evolutionary responses to environmental
  change

37
Case Study The Greater Prairie Chicken and the
Extinction Vortex

• Populations of the greater prairie chicken
• were fragmented by agriculture and later found to
  exhibit decreased fertility

38

• As a test of the extinction vortex hypothesis
• scientists imported genetic variation by
  transplanting birds from larger populations

39

• The declining population rebounded
• confirming that it had been on its way down an
  extinction vortex

40
Minimum Viable Population Size

• The minimum viable population (MVP)
• is the minimum population size at which a species
  is able to sustain its numbers and survive

41

• A population viability analysis (PVA)
• predicts a populations chances for survival over
  a particular time
• factors in the MVP of a population

42
Effective Population Size

• A meaningful estimate of MVP
• requires a researcher to determine the effective
  population size, which is based on the breeding
  size of a population

43
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

44

• This study has shown that the grizzly bear
  population
• has grown substantially in the past 20 years

45
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 in the first place

46
Steps for Analysis and Intervention

• The declining-population approach
• requires that population declines be evaluated on
  a case-by-case basis
• involves a step-by-step proactive conservation
  strategy

47
Case Study Decline of the Red-Cockaded Woodpecker

• Red-cockaded woodpeckers
• require specific habitat factors for survival
• had been forced into decline by habitat
  destruction

48

• In a study where breeding cavities were
  constructed
• new breeding groups formed only in these sites
• On the basis of this experiment
• a combination of habitat maintenance and
  excavation of new breeding cavities has enabled a
  once-endangered species to rebound

49
Weighing Conflicting Demands

• Conserving species often requires resolving
  conflicts
• between the habitat needs of endangered species
  and human demands

50

• Concept 55.3 Landscape and regional conservation
  aim to sustain entire biotas
• In recent years, conservation biology
• has attempted to sustain the biodiversity of
  entire communities, ecosystems, and landscapes

51

• One goal of landscape ecology, of which ecosystem
  management is part
• is to understand past, present, and future
  patterns of landscape use and to make
  biodiversity conservation part of land-use
  planning

52
Landscape Structure and Biodiversity

• The structure of a landscape
• can strongly influence biodiversity

53
Fragmentation and Edges

• The boundaries, or edges, between ecosystems
• are defining features of landscapes

54

• As habitat fragmentation increases
• and edges become more extensive, biodiversity
  tends to decrease

55

• Research on fragmented forests has led to the
  discovery of two groups of species
• those that live in forest edge habitats and those
  that live in the forest interior

56
Corridors That Connect Habitat Fragments

• A movement corridor
• is a narrow strip of quality habitat connecting
  otherwise isolated patches

57

• In areas of heavy human use
• artificial corridors are sometimes constructed

58

• Movement corridors
• promote dispersal and help sustain populations

59
Establishing Protected Areas

• Conservation biologists are applying their
  understanding of ecological dynamics
• in establishing protected areas to slow the loss
  of biodiversity

60

• Much of the focus on establishing protected areas
• has been on hot spots of biological diversity

61
Finding Biodiversity Hot Spots

• A biodiversity hot spot is a relatively small
  area
• with an exceptional concentration of endemic
  species and a large number of endangered and
  threatened species

62

• Biodiversity hot spots are obviously good choices
  for nature reserves
• but identifying them is not always easy

63
Philosophy of Nature Reserves

• Nature reserves are biodiversity islands
• in a sea of habitat degraded to varying degrees
  by human activity
• One argument for extensive reserves
• is that large, far-ranging animals with
  low-density populations require extensive habitats

64

• In some cases
• the size of reserves is smaller than the actual
  area needed to sustain a population

65
Zoned Reserves

• The zoned reserve model recognizes that
  conservation efforts
• often involve working in landscapes that are
  largely human dominated

66

• Zoned reserves
• are often established as conservation areas

67

• Some zoned reserves in the Fiji islands are
  closed to fishing
• which actually helps to improve fishing success
  in nearby areas

68

• Concept 55.4 Restoration ecology attempts to
  restore degraded ecosystems to a more natural
  state
• The larger the area disturbed
• the longer the time that is required for recovery

69

• Whether a disturbance is natural or caused by
  humans
• seems to make little difference in this size-time
  relationship

70

• One of the basic assumptions of restoration
  ecology
• is that most environmental damage is reversible
• Two key strategies in restoration ecology
• are bioremediation and augmentation of ecosystem
  processes

71
Bioremediation

• Bioremediation
• is the use of living organisms to detoxify
  ecosystems

72
Biological Augmentation

• Biological augmentation
• uses organisms to add essential materials to a
  degraded ecosystem

73
Exploring Restoration

• The newness and complexity of restoration ecology
• require scientists to consider alternative
  solutions and adjust approaches based on
  experience

74

• Concept 55.5 Sustainable development seeks to
  improve the human condition while conserving
  biodiversity
• Facing increasing loss and fragmentation of
  habitats
• How can we best manage Earths resources?

75
Sustainable Biosphere Initiative

• The goal of this initiative is to define and
  acquire the basic ecological information
  necessary
• for the intelligent and responsible development,
  management, and conservation of Earths resources

76
Case Study Sustainable Development in Costa Rica

• Costa Ricas success in conserving tropical
  biodiversity
• has involved partnerships between the government,
  other organizations, and private citizens

77

• Human living conditions in Costa Rica
• have improved along with ecological conservation

78
Biophilia and the Future of the Biosphere

• Our modern lives
• are very different from those of early humans who
  hunted and gathered and painted on cave walls

79

• But our behavior
• reflects remnants of our ancestral attachment to
  nature and the diversity of life, the concept of
  biophilia

80

• Our innate sense of connection to nature
• may eventually motivate a realignment of our
  environmental priorities