Transcript File _38_lecture_presentation

Chapter 38
Conservation Biology
PowerPoint Lectures for
Campbell Biology: Concepts & Connections, Seventh Edition
Reece, Taylor, Simon, and Dickey
© 2012 Pearson Education, Inc.
Lecture by Edward J. Zalisko
Introduction
 Over the past century, wild tiger populations have
been reduced from about 100,000 to 3,200.
 Tigers are threatened by
– declining habitat,
– poaching, and
– human populations encroaching into their habitat.
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Figure 38.0_1
Chapter 38: Big Ideas
The Loss of Biodiversity
Conservation Biology
and Restoration Ecology
Figure 38.0_2
THE LOSS OF
BIODIVERSITY
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38.1 Loss of biodiversity includes the loss of
ecosystems, species, and genes
 Biodiversity has three levels:
1. ecosystem diversity,
2. species diversity, and
3. genetic diversity.
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38.1 Loss of biodiversity includes the loss of
ecosystems, species, and genes
 As natural ecosystems are lost, so are essential
services, including
– productivity of natural environments for human food
supplies and
– the purification of water used by cities.
Video: Coral Reef
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Figure 38.1A
38.1 Loss of biodiversity includes the loss of
ecosystems, species, and genes
 At present, scientists have described and formally
named about 1.8 million species.
– It is difficult to estimate species loss.
– Species loss may be 1,000 times higher than at any time
in the past 100,000 years.
– Extirpation is the loss of a single population of a species.
– Extinction is the irreversible loss of all populations of a
species.
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Figure 38.1B
Percentage of species assessed
100%
80%
60%
40%
20%
0%
Mammals
(N  4,653)
Lowest risk
Amphibians
Birds
(N  9,933)
(N  4,688)
Near
threatened
Freshwater
fishes
(N  2,689)
Threatened
Reptiles
(N  1,429)
Extinct
38.1 Loss of biodiversity includes the loss of
ecosystems, species, and genes
 Because of the network of community interactions
among populations of different species within an
ecosystem,
– the loss of one species
– can negatively affect the species richness of an
ecosystem.
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Figure 38.1C
38.1 Loss of biodiversity includes the loss of
ecosystems, species, and genes
 Genetic diversity of a species is reduced if
– local populations are lost and
– the total number of individuals declines.
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Figure 38.1D
38.2 CONNECTION: Habitat loss, invasive
species, overharvesting, pollution, and
climate change are major threats to
biodiversity
 Human alteration of habitats poses the greatest
threat to biodiversity.
 Habitation alteration is caused by
– agriculture,
– urban development,
– forestry,
– mining, and
– environmental pollution.
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Figure 38.2A
38.2 CONNECTION: Habitat loss, invasive
species, overharvesting, pollution, and
climate change are major threats to
biodiversity
 Invasive species rank second behind habitat
destruction as a threat to biodiversity.
 Invasive species
– compete with native species,
– prey on native species, and
– parasitize native species.
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Figure 38.2B
38.2 CONNECTION: Habitat loss, invasive
species, overharvesting, pollution, and
climate change are major threats to
biodiversity
 Overexploitation is the third major threat to
biodiversity. Overharvesting has threatened
– rare trees,
– reduced populations of tigers, Galápagos tortoises,
whales, and rhinoceroses, and
– depleted wild populations of game fish.
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Figure 38.2C
38.2 CONNECTION: Habitat loss, invasive
species, overharvesting, pollution, and
climate change are major threats to
biodiversity
 Human activities produce diverse pollutants that may
affect ecosystems far from their source.
– The water cycle transfers pollutants from terrestrial to
aquatic ecosystems.
– The release of chemicals into the atmosphere promoted
the thinning of the ozone layer.
 Biological magnification concentrates synthetic
toxins that cannot be degraded by microorganisms.
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Figure 38.2D
Figure 38.2E
Concentration
of PCBs
Herring
gull eggs
124 ppm
Lake trout
4.83 ppm
Smelt
1.04 ppm
Zooplankton
0.123 ppm
Phytoplankton
0.025 ppm
38.3 CONNECTION: Rapid warming is changing
the global climate
 The scientific debate about global warming is over.
 Increased global temperatures caused by rising
concentrations of greenhouse gases are changing
climate patterns with grave consequences.
– Global temperature has risen 0.8°C in the last 100 years.
– 0.6°C of that increase occurred in the last three decades.
– 2 to 4.5°C increases are likely by the end of the 21st century.
– Temperature increases are not distributed evenly.
– Precipitation patterns are changing too.
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Figure 38.3A
4.1
4
2
1
0.5
0.2
0.2
0.5
1
2
4
4.1
Figure 38.3B
1938
1981
2005
Figure 38.3B_1
1938
Figure 38.3B_2
1981
Figure 38.3B_3
2005
38.4 CONNECTION: Human activities are
responsible for rising concentrations of
greenhouse gases
 Much of the rapid warming is the result of burning
fossil fuels.
– Atmospheric CO2 did not exceed 300 ppm for 650,000
years.
– The preindustrial concentration was below 300 ppm.
– Atmospheric CO2 is approximately 385 ppm today.
– High levels of methane and nitrous oxide also trap heat.
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Figure 38.4A
2,000
1,800
Carbon Dioxide (CO2)
Nitrous Oxide (N2O)
350
1,600
Methane (CH4)
1,400
1,200
300
1,000
800
250
600
0
500
1000
Year
1500
2000
CH4 (parts per billion)
CO2 (ppm), N2O (parts per billion)
400
Figure 38.4B
Photosynthesis
Atmosphere
Respiration
Combustion of
fossil fuels
Ocean
38.5 Global climate change affects biomes,
ecosystems, communities, and populations
 Climate change in western North America has
spawned catastrophic wildfires.
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Figure 38.5A
38.5 Global climate change affects biomes,
ecosystems, communities, and populations
 The greatest impact of global climate change is
affecting organisms that live at
– high latitudes and
– high elevations.
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Figure 38.5B
38.5 Global climate change affects biomes,
ecosystems, communities, and populations
 Warming oceans threaten coral reef communities.
 Earlier arrival of warm temperatures in the spring is
disturbing ecological communities.
– Birds and frogs have begun their breeding periods earlier.
– Migratory birds may experience mismatches, arriving
after peak food availability has already passed.
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38.5 Global climate change affects biomes,
ecosystems, communities, and populations
 Climate change has also
– increased the range of disease-carrying mosquitoes and
– enabled bark beetles to reproduce faster, promoting the
destruction of millions of acres of conifers in western
North America.
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38.6 EVOLUTION CONNECTION: Climate
change is an agent of natural selection
 Phenotypic plasticity
– has minimized the impact of global climate change on
some species, and
– cases of microevolutionary changes have been observed.
– The rapidity of the environmental changes makes it
unlikely that evolutionary processes will save many
species from extinction.
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38.6 EVOLUTION CONNECTION: Climate
change is an agent of natural selection
 In Europe, the great tit bird
– has shifted its breeding season earlier, in an example of
directional selection,
– favoring individuals that lay their eggs sooner, and
– better matching the earlier emergence of caterpillars.
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Figure 38.6A
38.6 EVOLUTION CONNECTION: Climate
change is an agent of natural selection
 In the Yukon Territory of Canada,
– where the spring temperatures have increased by
about 2°C,
– red squirrels have begun breeding earlier in the spring.
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Figure 38.6B
CONSERVATION BIOLOGY
AND RESTORATION ECOLOGY
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38.7 Protecting endangered populations is one
goal of conservation biology
 Conservation biology is a goal-driven science that
seeks to
– understand and
– counter the rapid loss of biodiversity.
 Some conservation biologists direct their efforts at
– protecting populations and
– increasing endangered populations.
– Threats posed by human activities are also assessed.
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38.7 Protecting endangered populations is one
goal of conservation biology
 The black-footed ferret in the United States
– is one of three ferret species worldwide and the only
ferret found in North America,
– was reduced to just 18 individuals,
– has been bred in captivity, and
– was reintroduced into the wild.
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Figure 38.7A
38.7 Protecting endangered populations is one
goal of conservation biology
 In Hawaii, the silversword plants once abundant on
the cinder cone of the volcano Mauna Kea
– were bred in greenhouses and
– reintroduced to reestablish wild populations.
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Figure 38.7B
38.8 Sustaining ecosystems and landscapes is a
conservation priority
 Conservation efforts are increasingly aimed at
sustaining
– ecosystems and
– landscapes, a regional assemblage of interacting
ecosystems.
 Landscape ecology is the application of ecological
principles to the study of the structure and dynamics
of a collection of ecosystems.
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Figure 38.8A
38.8 Sustaining ecosystems and landscapes is a
conservation priority
 Edges between ecosystems have distinct sets of
features and species.
 The increased frequency and abruptness of edges
caused by human activities can increase species
loss.
 Movement corridors connecting isolated habitats
may be helpful to fragmented populations.
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Figure 38.8B
Figure 38.8C
38.9 Establishing protected areas slows the loss of
biodiversity
 To establish parks, wilderness areas, and other
legally protected reserves, conservation biologists
are applying their understanding of
– population,
– ecosystem, and
– landscape dynamics.
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38.9 Establishing protected areas slows the loss of
biodiversity
 Choosing locations for protection often focuses on
biodiversity hot spots, relatively small areas with
– a large number of endangered and threatened species,
and
– an exceptional concentration of endemic species, those
that are found nowhere else.
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Figure 38.9A
Equator
38.9 Establishing protected areas slows the loss of
biodiversity
 Migratory species pose a special problem for
conservationists.
– Monarch butterflies occupy many areas.
– Sea turtles travel great distances.
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Figure 38.9B
Figure 38.9_UN
38.10 Zoned reserves are an attempt to reverse
ecosystem disruption
 Zoned reserves are undisturbed wildlands
surrounded by buffer zones of compatible economic
development.
 Costa Rica has established many zoned reserves.
 Ecotourism
– is travel to natural areas for tourism and recreation and
– has become an important source of revenue for
conservation efforts.
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Figure 38.10A
NICARAGUA
COSTA RICA
PANAMA
National Parks and Reserves
Figure 38.10B
38.11 CONNECTION: The Yellowstone to Yukon
Conservation Initiative seeks to preserve
biodiversity by connecting protected areas
 The Yellowstone to Yukon Conservation Initiative
– created a string of parks and reserves in a 3,200-km
wildlife corridor,
– extends from Alaska south across Canada to northern
Wyoming,
– included the reintroduction of wolf populations,
considered a keystone species in this region, and
– sparked angry protests from some ranchers.
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Figure 38.11A
YUKON
TERRITORY
NORTHWEST TERRITORIES
Whitehorse
ALBERTA
PACIFIC
OCEAN
BRITISH
COLUMBIA
Calgary
Vancouver
MONTANA
Spokane
WASHINGTON
Bozeman
Jackson
OREGON
IDAHO
WYOMING
Figure 38.11A_1
YUKON
TERRITORY
NORTHWEST TERRITORIES
Whitehorse
ALBERTA
Figure 38.11A_2
PACIFIC
OCEAN
BRITISH
COLUMBIA
Calgary
Vancouver
MONTANA
Spokane
WASHINGTON
Bozeman
Jackson
OREGON
IDAHO
WYOMING
Figure 38.11B
Figure 38.11C
38.12 CONNECTION: The study of how to restore
degraded habitats is a developing science
 Restoration ecology uses ecological principles to
restore degraded areas to their natural state, a
process that may include
– detoxifying polluted ecosystems,
– replanting native vegetation, and
– returning waterways to their natural course.
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38.12 CONNECTION: The study of how to restore
degraded habitats is a developing science
 Large-scale restoration projects attempt to restore
damaged landscapes.
 The Kissimmee River Restoration Project in Florida
is
– restoring river flow and wetlands and
– improving wildlife habitat.
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Figure 38.12A
Widened
canal
Water control
structure remaining
Water control
structure removed
Phase 1
River channel
completed
restored
Canal backfilled
Water control
structure to
be removed in
Kissimmee
Phase 2
River
Floodplain
FLORIDA
0
Miles
10
Figure 38.12B
Former canal
38.13 Sustainable development is an ultimate goal
 Sustainable development
– seeks to improve the human condition while conserving
biodiversity,
– depends on increasing and applying ecological
knowledge, and
– values our linkages to the biosphere.
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38.13 Sustainable development is an ultimate goal
 We are most likely to
– save what we appreciate and
– appreciate what we understand.
 Now is the time to
– aggressively pursue more knowledge about life and
– work toward long-term sustainability.
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Figure 38.13
You should now be able to
1. Describe the three components of biodiversity.
2. Describe the greatest current threats to biodiversity,
providing examples of each.
3. Describe the process of biological magnification.
4. Describe the causes and consequences of global
warming.
5. Explain why the efforts to save the black-footed
ferret and silversword plant from extinction are a
good model for future conservation efforts.
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You should now be able to
6. Describe the goals of landscape ecology. Describe
the significance of edges and movement corridors
in maintaining biodiversity.
7. Describe the significance of biodiversity hotspots.
8. Explain how zoned reserves are being used to
protect ecosystems.
9. Describe the goals of the Yukon to Yellowstone
Initiative.
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You should now be able to
10. Describe the goals and methods of restoration
ecology.
11. Explain why sustainable development should be
the ultimate goal for the long-term maintenance of
human societies and the ecosystems that support
them.
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Figure 38.UN01
Ecosystem
diversity
Species
diversity
Genetic
diversity
Figure 38.UN02
Conservation
biology
seeks to conserve
may involve
ecosystems and
landscapes
(a)
may be
protected in
attempt
to restore
nature
reserves
restoration
projects
which uses
(c)
ATLANTIC
OCEAN
may be
to
FLORIDA
(d)
which support
sustainable
development
GULF OF
MEXICO
detoxify or
replenish degraded
ecosystems