LIVING IN THE ENVIRONMENT, 18e
G. TYLER MILLER • SCOTT E. SPOOLMAN
9Sustaining Biodiversity:
Saving Species and Ecosystem
Services
©©Cengage
CengageLearning
Learning2015
2015
Core Case Study: Where Have All the
Honeybees Gone?
• Bees play a key role in pollination
• Globally, about one third of the food supply
comes from insect-pollinated plants
• Currently, agriculture depends heavily on a
single species of bee
– Suffering from Colony Collapse Disorder
• Each year, 30-50% of colonies in Europe and the
U.S.
• Watch this Bee CCD Viddy…
© Cengage Learning 2015
Case Study: Protecting Honeybees and
Other Pollinators
• Failure to protect honeybees
– Loss of vital ecosystem services
• Farmers are:
– Breeding bees resistant to harmful parasitic
mites and fungi
– Raising their own colonies
– Improving bee nutrition
© Cengage Learning 2015
Honeybee
Fig. 9-1, p. 190
Core Case Study: The Passenger Pigeon:
Gone Forever
• Passenger pigeon hunted to extinction by 1900
• Commercial hunters used "stool pigeons”
(decoy), giant nets, or setting fire to nesting
trees
• Archeological record shows evidence of five
mass extinctions
• Human activities: hastening more extinctions?
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Human Activities Are Destroying and
Degrading Biodiversity
• Human activity has disturbed at least half
of the earth’s land surface
– Fills in wetlands
– Converts grasslands and forests to crop fields
and urban areas
• Degraded aquatic biodiversity in a wide
array of ways
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9-1 What Role Do Humans Play in the
Loss of Species and Ecosystem Services?
• Species are becoming extinct 100 to 1,000
times faster than they were before modern
humans arrived on the earth
– By the end of this century, the extinction rate
is expected to be 10,000 times higher than
that background rate
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Extinctions Are Natural but Sometimes
They Increase Sharply
• Background extinction – continuous
low level extinctions which occur
naturally (without human involvement,
since beginning of time…)
• Extinction rate – the percent or number
of species that go extinct in a certain
time period
• Mass extinction (50-90% of species)
Causes?
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Levels of Species Extinction
• Biological extinction
– No species member alive
• Trophic cascade - Trophic cascades occur when
predators limit the density and/or behavior of their prey
and thereby enhance survival of the next lower trophic
level.
• Mass extinction
– Many species in a short amount of time
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Some Human Activities Hasten Extinctions
and Threaten Ecosystem Services
• Background extinction rate
– 1 extinct species / 1 million species / year (based on studies of
marine fossils, since humans are a “young” species..)
• Extinction rates have risen recently
• Using data for recent extinctions among birds and mammals (which
are pretty well known), we can estimate that about 1% of species go
extinct every 100 years.
• This means that about 1 in every 10,000 species are currently going
extinct each year.
• These estimates suggest that the current extinction rate is about
100-1000 times greater than the background rate. Other estimates
that have been made range from about 40 times the background
rate, to 10,000 times the background rate.
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Animal Species Prematurely Extinct Due to
Human Activities
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Some Human Activities Hasten Extinctions
and Threaten Ecosystem Services (cont’d.)
• Rate of extinction and threats to
ecosystem services likely to rise sharply in
the next 50-100 years
– Due to harmful human impacts
• Biodiversity hotspots
– Extinction rates projected to be much higher
than average
• Biologically diverse environments are
being eliminated or fragmented
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Effects of a 0.1% Extinction Rate
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Endangered and Threatened Species Are
Ecological Smoke Alarms
• Endangered species
– So few members that the species could soon
become extinct
• Threatened species (vulnerable species)
– Still enough members to survive, but numbers
declining
– May soon be endangered
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Endangered and Threatened Species Are
Ecological Smoke Alarms (cont’d.)
• Regionally extinct
– In areas a species is normally found
• Functionally (ecologically) extinct
– To the point at which species can no longer
play a functional role in the ecosystem
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Fig. 9-2, p. 193
Endangered Natural Capital: Species
Threatened with Premature Extinction
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Characteristics of Species That Are Prone
to Ecological and Biological Extinction
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Percentage of Various Species Threatened
with Premature Extinction
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9-2 Why Should We Care about the Rising
Rate of Species Extinction?
• We should avoid speeding up the
extinction of wild species because:
– Of the ecosystem and economic services they
provide
– It can take millions of years for nature to
recover from large-scale extinctions
– Many people believe that species have a right
to exist regardless of their usefulness to us
(ethics)
© Cengage Learning 2015
Species Are a Vital Part of the Earth’s
Natural Capital
• Major reasons to prevent extinctions
• Species provide vital ecosystem services
– Help keep us alive and support our
economies
• Many species also contribute economic
services
– Plants for food, fuel, lumber, and medicine
– Ecotourism
© Cengage Learning 2015
Species Are a Vital Part of the Earth’s
Natural Capital (cont’d.)
• It will take 5-10 million years to regain
species biodiversity after this century’s
extinctions
• Many people believe species have an
intrinsic right to exist
• How do we decide which species to
protect?
© Cengage Learning 2015
Nature’s Pharmacy
Pacific yew
Taxus
brevifolia,
Pacific
Northwest
Ovarian cancer
Rauvolfia
Rauvolfia sepentina,
Southeast Asia
Anxiety, high blood
pressure
Foxglove
Digitalis
purpurea, Europe
Digitalis for heart
failure
Rosy
periwinkle
Cathranthus
roseus,
Madagascar
Hodgkin's
disease,
Cinchona
lymphocytic
Cinchona
leukemia
ledogeriana, South
America Quinine
for malaria
treatment
Neem tree
Azadirachta
indica, India
Treatment of
many diseases,
insecticide,
spermicides
Fig. 9-6, p. 196
Many species of
wildlife such as this
endangered hyacinth
macaw in Mato
Grosso, Brazil, are
sources of beauty
and pleasure. It is
endangered because
of habitat loss and
illegal capture in the
wild by pet traders.
Fig. 9-7, p. 196
9-3 How Are We Threatening Species and
Ecosystem Services?
• The greatest threats to any species are (in
order):
– Loss or degradation of its habitat
– Harmful invasive species
– Human population growth
– Pollution
– Climate change
– Overexploitation
© Cengage Learning 2015
Loss of Habitat Is the Single Greatest
Threat to Species: Remember HIPPCO
• Habitat destruction, degradation, and
fragmentation
• Invasive (nonnative) species
• Population and resource use growth
• Pollution
• Climate change
• Overexploitation
© Cengage Learning 2015
Loss of Habitat Is the Single Greatest
Threat to Species (cont’d.)
• Habitat fragmentation
– Large intact habitat divided by roads, crops,
and urban development
• National parks and nature reserves as
habitat islands
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Causes of Depletion and Premature
Extinction of World Species
© Cengage Learning 2015
Indian
Tiger
Range 100 years ago
Range today
African
Elephant
Probable range 1600
Range today
Black
Rhino
Range in 1700
Range today
Asian or Indian
Elephant
Former range
Range today
Natural capital
degradation: These
maps reveal the
reductions in the
ranges of four
wildlife species,
mostly as the result
of severe habitat loss
and fragmentation
and illegal hunting
for some of their
valuable body parts.
Question: Would you
support expanding
these ranges even
though this would
reduce the land
available for human
habitation and
farming? Explain.
Stepped Art
Fig. 9-8, p. 198
We Have Moved Disruptive Species into
Some Ecosystems
• Many species introductions are beneficial
• Nonnative species may have no natural:
– Predators, competitors, parasites, pathogens
• Nonnative species can crowd out native
species
– Invasive species
© Cengage Learning 2015
Deliberately introduced species
These are some
of the estimated
7,100 harmful
invasive species
that have been
deliberately or
accidentally
introduced into
the United
States.
Purple
European
loosestrife starling
Marine toad
(Giant toad)
African honeybee Nutria
(“Killer bee”)
Water
hyacinth
Japanese
beetle
Hydrilla
Salt cedar
(Tamarisk)
European wild
boar (Feral pig)
Accidentally introduced species
Sea lamprey
(attached to
lake trout)
Formosan
termite
Argentina
fire ant
Brown tree
snake
Eurasian
ruffe
Common pigeon
(Rock dove)
Zebra
mussel
Asian long-
Stepped Art
Asian tiger Gypsy
moth
Fig. 9-9,
p. 199
Case Study: The Kudzu Vine and Kudzu
Bugs
• Imported from Japan in the 1930s
– Help control soil erosion
• Very difficult to kill
• Could there be benefits of kudzu?
• Kudzu bug – imported from Japan
– Can kill Kudzu vine
– Also kills soybeans
© Cengage Learning 2015
Kudzu
has
grown
over
this car
in the
U.S.
state of
Georgia
Fig. 9-10, p. 200
Some Accidentally Introduced Species
Can Disrupt Ecosystems
• Argentina fire ant – introduced in the
1930s
– Reduced populations of native ants
– Painful stings can kill
– Pesticide spraying in 1950s and 1960s
worsened conditions
– Tiny parasitic flies may help control fire ants
© Cengage Learning 2015
Case Study: Burmese Pythons Are Eating
Their Way through the Florida Everglades
• Accidentally introduced
• Reproduce rapidly and are hard to kill
• Greatly depleted Everglades populations
of:
– Rabbits, foxes, raccoons, opossums, and
deer
* The next slide shows University of Florida researchers holding a
15 foot long Burmese Python, caught in the everglades after it had
eaten a 6 foot long American Alligator
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Fig. 9-11, p. 201
Prevention Is the Best Way to Reduce
Threats from Invasive Species
• Research programs identifying invaders
• Establishing international treaties banning
transfer between countries
• Public education about exotic pets and
plants
• What else can be done to prevent invasive
species?
© Cengage Learning 2015
Fig. 9-12, p. 202
Other Causes of Species Extinctions
• Human population growth and
overconsumption
– Degrading habitat
• Pollution
– Bioaccumulation can cause extinctions of
species not directly affected by pollution
• Climate change
– Some species will become extinct, some will
spread
© Cengage Learning 2015
DDT in fish-eating
birds (ospreys)
25 ppm
DDT in large fish
(needle fish)
2 ppm
DDT in small
fish (minnows)
0.5 ppm
DDT in
zooplankton
0.04 ppm
DDT in water
0.000003 ppm,
or 3 ppt
Stepped Art
Fig. 9-13, p. 202
Case Study: Polar Bears and Climate
Change
• Live only in the Arctic
• Arctic ice is melting
– Decreasing polar bear habitat
– Polar bears must swim farther between ice
• Weaker females; less reproduction
© Cengage Learning 2015
© Cengage Learning 2015
Fig. 9-14, p. 204
Illegal Killing, Capturing, and Selling of
Wild Species Threatens Biodiversity
• Poaching and smuggling of animals and
plants
– Animal parts
– Pets
– Plants for landscaping and enjoyment
• Prevention
– Research and education
© Cengage Learning 2015
Fig. 9-15, p. 205
A Rising Demand for Bushmeat Threatens
Some African Species
• West and Central African wild animals
– Supply major cities with exotic meats
• Hunting has driven one species to
extinction
– Miss Waldron’s red colobus monkey
• Threatened species:
– Monkeys, apes, antelope, elephants, and
hippos
© Cengage Learning 2015
Bush Meat: Lowland Gorilla
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Case Study: A Disturbing Message
from the Birds
• 70% of the world’s bird species are
declining
• Habitat loss and fragmentation of the birds’
breeding habitats
– Forests cleared for farms, lumber plantations,
roads, and development
• Intentional or accidental introduction of
nonnative species
– These species eat the birds
© Cengage Learning 2015
Case Study: A Disturbing Message
from the Birds (cont’d.)
• Exposure to pesticides
• Overexploitation
– For pets
• Birds are indicator species
– Respond quickly to environmental changes
• Birds perform critical ecosystem and
economic services
– Extinctions could affect many other species
© Cengage Learning 2015
This
endangered
Attwater’s
prairie
chicken lives
in a wildlife
refuge in the
U.S. state of
Texas.
Fig. 9-17, p. 206
9-4 How Can We Sustain Wild Species
and Their Ecosystem Services?
• We can reduce species extinction and
sustain ecosystem services by:
– Establishing and enforcing national
environmental laws and international treaties
– Creating protected wildlife sanctuaries
– Taking precautionary measures to prevent
such harm
© Cengage Learning 2015
9-4 How Can We Protect Wild Species
from Premature Extinction? (1)
• We can use existing environmental laws
and treaties and work to enact new laws
designed to prevent species extinction and
protect overall biodiversity.
• We can help to prevent species extinction
by creating and maintaining wildlife
refuges, gene banks, botanical gardens,
zoos, and aquariums.
© Cengage Learning 2015
9-4 How Can We Protect Wild Species
from Premature Extinction? (2)
• According to the precautionary principle,
we should take measures to prevent or
reduce harm to the environment and to
human health, even if some of the causeand-effect relationships have not been
fully established, scientifically.
© Cengage Learning 2015
International Treaties and National Laws
Help to Protect Species
• 1975 – Convention on International Trade
in Endangered Species (CITES)
– Signed by 172 countries
• Convention on Biological Diversity (BCD)
– Focuses on ecosystems
– Ratified by 190 countries (not the U.S.)
© Cengage Learning 2015
Case Study: The U.S. Endangered
Species Act
• Endangered Species Act (ESA) – 1973
and later amended in 1982, 1985, and
1988
– Identify and protect endangered species in
the U.S. and abroad
• National Marine Fisheries Service for
ocean species
• U.S. Fish and Wildlife Service for all others
© Cengage Learning 2015
ESA
• Endangered Species Act (ESA): 1973 and later
amended in 1982, 1983, and 1985 – Identify and
protect endangered species in the U.S. and
abroad and outlaws the sale of these species or
products made from these species
• Hot Spots – areas of especially rare and
imperiled species
• Habitat Conservation Plan (HCP) colony –
allows habitat destruction in exchange for
habitat conservation/protections elsewhere
© Cengage Learning 2015
Case Study: The U.S. Endangered
Species Act (cont’d.)
• Forbids federal agencies (except Defense)
from funding or authorizing projects that
jeopardize endangered or threatened
species
– In 2012, 1,394 species officially listed
• Offer incentives to private property owners
to help
© Cengage Learning 2015
Case Study: The U.S. Endangered
Species Act (cont’d.)
• Is the ESA a failure?
– Species are listed only when in serious
danger
– Conditions for more than half of listed species
are stable or improving
– Budget is about 57 cents per U.S. citizen
© Cengage Learning 2015
Case Study: The U.S. Endangered
Species Act (2)
• Mixed reviews of the ESA
– Weaken it
– Repeal it
– Modify it
– Strengthen it
– Simplify it
– Streamline it
© Cengage Learning 2015
Science Focus: Accomplishments
of the Endangered Species Act (2)
• Suggested changes to ESA
– Increase the budget
– Develop recovery plans more quickly
– Establish a core of the endangered
organism’s survival habitat
© Cengage Learning 2015
Confiscated Products Made from
Endangered Species
© Cengage Learning 2015
The American
bald eagle has
been removed
from the U.S.
endangered
species list.
Here, an eagle
is about to
catch a fish in
its powerful
talons.
Fig. 9-19, p. 209
We Can Establish Wildlife Refuges
and Other Protected Areas
• In 1903, Theodore Roosevelt established
the first federal wildlife refuge
– Pelican Island, Florida
• Wildlife refuges
– Most are wetland sanctuaries
– More needed for endangered plants
– Are not immune from disturbance
© Cengage Learning 2015
Fig. 9-20, p. 210
Seed Banks, Botanical Gardens, and
Wildlife Farms Can Help Protect Species
• Seed banks
– Preserve genetic material of endangered
plants
• Botanical gardens and arboreta
– Living plants
• Farms can raise organisms for commercial
sale
© Cengage Learning 2015
Zoos and Aquariums Can Protect
Some Species
• Techniques for preserving endangered
terrestrial species
– Egg pulling
– Captive breeding
– Artificial insemination
– Embryo transfer
– Use of incubators
– Cross-fostering
© Cengage Learning 2015
Zoos and Aquariums Can Protect
Some Species (cont’d.)
• Goal of ultimately releasing/reintroducing
populations to the wild
• Limited space and funds
© Cengage Learning 2015
The Monterey Bay
Aquarium in
Monterey,
California (USA),
contains this
tidewater pool,
which is used to
train rescued sea
otter pups to
survive in the wild.
Fig. 9-21, p. 211
© Cengage Learning 2015
Fig. 9-22, p. 212
The Precautionary Principle
• Precautionary principle
– Act to prevent or reduce harm when
preliminary evidence indicates acting is
needed
• Species are the primary components of
biodiversity
• Should we focus on the preservation of
species or the preservation of
ecosystems?
© Cengage Learning 2015