Transcript video slide - Ethical Culture Fieldston School

Chapter 38
Conservation Biology
PowerPoint Lectures for
Biology: Concepts and Connections, Fifth Edition
– Campbell, Reece, Taylor, and Simon
Lectures by Chris Romero
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Saving the Tiger
• Tigers once roamed across Asia, but hunting
has drastically reduced their populations
• Intense conservation efforts by the Myanmar
government have begun to save the tigers
• The story of the tiger illustrates the biodiversity
crisis, a rapid decrease in Earth's plant and
animal diversity
• Conservation biology is a goal-oriented
science that seeks to counter the biodiversity
crisis
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THE BIODIVERSITY CRISIS: AN OVERVIEW
38.1 Human activities threaten Earth's
biodiversity
• Scientists have described about 1.8 million
species
• Global extinction rates may be 1,000 times
higher than any time in the past 100,000 years
• Biodiversity has three levels
– Genetic diversity
– Species diversity
– Ecosystem diversity
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• Human activities threaten diversity at all levels
– Alter trophic structure, energy flow,
chemical recycling, and natural
disturbances
– Many species are endangered or
threatened
Video: Coral Reef
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38.2 Biodiversity is vital to human welfare
• There are practical as well as ethical and
aesthetic reasons for preserving biodiversity
– Provides food, fiber, medicines, etc.
• Loss of genetic diversity means loss of
opportunities for future benefits
• Large-scale alterations in the biosphere
threaten the human population
– Ecosystem services have been valued at
$33 trillion annually
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38.3 Habitat destruction, introduced species, and
overexploitation are the major threats to
biodiversity
• Human alteration of habitat is the greatest
single threat to biodiversity
• Introduced species can disrupt communities by
competing with or preying on native species
• Overexploitation of wildlife by harvesting has
threatened various animal and plant species
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CONNECTION
38.4 Pollution of the environment compounds our
impact on other species
• Human release of pollutants can have local,
regional, and global effects
– CFCs leading to depletion of the ozone
layer
– Eutrophication of lakes and streams
– Biological magnification of chemicals
– Synthetic chemicals that cannot be
biodegraded
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LE 38-4
Herring
gull eggs
124 ppm
Lake trout
4.83 ppm
Smelt
1.04 ppm
Zooplankton
0.123 ppm
Phytoplankton
0.025 ppm
CONNECTION
38.5 Rapid global warming could alter the entire
biosphere
• Burning of fossil fuels is increasing the amount
of CO2 and other greenhouse gases in the air
– Correlation with increased global
temperature
• The greenhouse effect
– Natural phenomenon is essential for life on
Earth
– Rapidly increasing CO2 is making global
warming a danger
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LE 38-5a
390
1.05
380
0.90
0.75
Temperature
0.60
360
0.45
350
0.30
340
CO2
0.15
330
0
320
–0.15
310
–0.30
300
–0.45
2005
1960
1965
1970
1975
1980 1985
Year
1990
1995
2000
Temperature variation (°C)
CO2 concentration (ppm)
370
LE 38-5b
Global warming:
CO2 lets sunlight
through but retains
the heat radiated
from Earth.
Human activities and natural
processes add CO2 to the
atmosphere, increasing the effect.
Photosynthesis removes
CO2 from the atmosphere,
decreasing the effect.
CO2
CO2 in the
atmosphere
CO2 CO2
• Possible consequences of increased global
warming
– Melting of polar ice and rising sea levels
– Changing climate patterns
– Habitat alteration and consequent loss of
species
– Effects on human health
• Most scientists and world leaders believe
global warming must be combated immediately
– Lifestyle changes necessary
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CONSERVATION OF POPULATIONS AND SPECIES
38.6 Two ways to study endangered populations
are the small-population approach and the
declining-population approach
• Population fragmentation is one of the most
harmful effects of habitat loss
• Small-population approach
– Attempts to prevent extinction vortex
– Identifies minimum viable population size
– Focuses on preserving genetic variation
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• Declining-population approach
– Follows logical series of steps to halt
population declines
• Confirm that species is in decline
• Determine species' environmental
requirements
• Develop hypotheses for causes of
decline
• Test most likely hypotheses first
• Apply results of diagnosis to
management of threatened species
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38.7 Identifying critical habitat factors can guide
conservation efforts
• Preserving critical habitat may help
endangered species recover
– Example: red-cockaded woodpecker
• Management for one species can affect other
species negatively or positively
• Human demands conflicting with habitat
preservation must be considered
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MANAGING AND RESTORING ECOSYSTEMS
38.8 Sustaining ecosystems and landscapes is a
conservation priority
• Landscape ecology
– Application of ecological principles to the
study of a collection of ecosystems
– Goal to study human land-use patterns to
make biodiversity conservation a priority
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• Edges between ecosystems are prominent
features of landscapes
– Have distinct features and species
– Human-caused edge communities may be
dominated by few edge-adapted species
• Movement corridors can connect fragmented
habitats
– May be important in preserving biodiversity
– Can promote dispersal and prevent
inbreeding
– Can sometimes be harmful
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38.9 Protected areas are established to slow the
loss of biodiversity
• Biodiversity hot spots
– Small areas with many endangered or
threatened species
– Have large concentrations of endemic
species
• Highly sensitive to habitat degradation
– Provide an opportunity to protect many
species in very limited areas
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• Migratory species may require international
protection
• National parks and reserves are generally too
small to achieve minimal viable population size
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LE 38-9a
Equator
CONNECTION
38.10 The Yellowstone to Yukon Conversation
Initiative seeks to preserve biodiversity by
connecting protected areas
• The Y2Y Initiative is creating ways to give
creatures more room
– Aims to preserve web of life that has
defined the Rocky Mountains of the United
States and Canada
– Seeks to connect parks with protected
wildlife corridors
– Return of gray wolves is a program success
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LE 38-10a
Yellowstone to Yukon
Ecoregion
YUKON
TERRITORY
NORTHWEST TERRITORIES
ALBERTA
BRITISH
COLUMBIA
YELLOWSTONE TO YUKON
CONSERVATION INITIATIVE
MONTANA
LEGEND
Major Highways
WASHINGTON
Protected areas
Y2Y Ecoregion
105
420
0 105 210 315 Km
OREGON
IDAHO
WYOMING
38.11 The study of how to restore degraded
habitats is a developing science
• Restoration ecology uses ecological principles
to return degraded ecosystems to conditions
similar to their natural state
• Bioremediation uses living organisms to
detoxify polluted ecosystems
– Removes harmful substances
• Bioaugmentation uses organisms to add
essential materials to degraded ecosystems
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CONNECTION
38.12 The Kissimmee River project is a case
study in restoration ecology
• Population growth and development put
ecological pressures on the Kissimmee River
• The Kissimmee River Restoration Project is
one of the world's largest restoration projects
– Restoring natural river flow
– Reclaiming wetlands
– Improving water quality and wildlife habitat
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LE 38-12a
Former
canal
38.13 Zoned reserves are an attempt to reverse
ecosystem disruption
• A zoned reserve is an extensive region of land
that includes
– One or more areas undisturbed by humans
– Surrounding buffer zones of compatible
economic development
• Shield against further development
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• Zoned reserves contribute to sustainable
development
– Long-term prosperity of human societies
and the ecosystems that support them
– Costa Rica an example of success
• Commitment to conservation is
challenged by growing population
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LE 38-13a
Nicaragua
Costa
Rica
National parkland
Buffer zone
Pacific Ocean
Caribbean Sea
38.14 Sustainable development is an ultimate
goal
• Sustainable Biosphere Initiative
– Aims to acquire the information necessary
to develop, manage, and conserve the
Earth's resources in a responsible manner
• Sustainable development also requires
education and political commitment
• Humans must seek ways to be more
accommodating with other species and with
the biosphere
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings