Transcript invasive species

Sustaining Wild Species
G. Tyler Miller’s
Living in the Environment
14th Edition
Chapter 12
Dr. Richard Clements
Chattanooga State Technical Community College
Key Concepts
Human effects on biodiversity
Importance of biodiversity
How human activities affect wildlife
Management of wildlife
Human Impacts on Biodiversity
Water use and pollution
and soil nutrient loss
Food supply
and demand
Changes in
water
water supply
supply and
and
temperature
temperature
Freshwater
supply and
demand
Water availability
Deforestation
Changes in
precipitation
and temperature
CO2, CH4,
N2O emissions
Erosion,
pollution, and
changes in
water flow
Habitat change
and fragmentation
of habitat
Climate change
Forest product
supply and
demand
CO2 emission
Changes in
transpiration
and albedo
Habitat
change
Loss
of crop
genetic
diversity
Loss and
fragmentation
of habitat
Biodiversity loss
Loss and
fragmentation
of habitat
Reduced
resistance
to change
Fig. 22.2, p. 551
Preserving Biodiversity
Tori Haidinger
Dr. Richard Clements
Increasing Biodiversity
Physically diverse habitat
Moderate environmental disturbance
Small variations in conditions
Middle stages of ecological succession
Decreasing Biodiversity
Environmental stress
Large environmental disturbance
Extreme environmental conditions
Severe limiting factors
Introduction of alien species
Geographic isolation
Species Extinction – 3 types
Local extinction
Ecological extinction
Biological extinction
Endangered and Threatened Species
Endangered species
Threatened (vulnerable) species
Rare species
Florida
manatee
Northern spotted Gray wolf
owl (threatened)
Florida panther Bannerman's
turaco (Africa)
Fig. 22.7a, p. 556
Grizzly bear
Utah prairie dog
Kirkland’s
warbler
Knowlton
cactus
Florida
manatee
Swallowtail
butterfly
Humpback
chub
Golden lion
tamarin
African elephant
Siberian tiger
Fig. 11-3, p. 224
Giant panda Black-footed Whooping
crane
ferret
Mountain gorilla Florida
panther
California
condor
Northern
spotted owl
Hawksbill
sea turtle
Blue whale
Black
rhinoceros
Fig. 11-3, p. 224
Extinction Risks
Factors: population size, habitat, and
genetics
Minimum viable population
– the smallest population size that is
able to sustain the species
– enough males and females
– enough genetic diversity
Minimum dynamic area
Passenger pigeon
Great auk
Dodo
Dusky seaside
sparrow
Aepyornis
(Madagascar)
Fig. 11-2, p. 223
Characteristics
of extinctionprone species
(refer to Fig. 22-8 p.
558)
Characteristic
Examples
Low reproductive rate
(K-strategist)
Blue whale, giant panda,
rhinoceros
Specialized niche
Blue whale, giant panda,
Everglades kite
Narrow distribution
Many island species,
elephant seal, desert pupfish
Feeds at high trophic
level
Bengal tiger, bald eagle,
grizzly bear
Fixed migratory patterns
Blue whale, whooping crane,
sea turtles
Rare
Many island species,
African violet, some orchids
Commercially valuable
Snow leopard, tiger,
elephant, rhinoceros,
rare plants and birds
Large territories
California condor, grizzly
bear, Florida panther
Extinction Rates
Background (natural) rate of extinction
Geological Periods
Adaptive
radiations
Number of families
of marine animals
Mass
extinction
Carboniferous
Cretaceous
Devonian
Jurassic
Silurian
Triassic
Tertiary
Ordovician
Permian
Quaternary
Cambrian
800
Mass extinctions
600
?
400
200
0
570
505
438
360
408
286
208 144
245
Millions of years ago
65
0
2
Fig. 22.10, p. 558
How do we benefit from
biodiversity?
• Food
– up to 80,000 edible plants could be utilized
– villagers in Indonesia use 4000 plant and
animal species
• Drugs and Medicines
– more than half of all prescriptions contain
natural products
– cancer fighting drugs
– Merck pays Costa Rica $1 million for samples
How do we benefit from biodiversity?
• Ecological Benefits
– interdependence of species
– nutrient cycling
– regulation of species (regulation of pests)
• Aesthetic and Cultural Benefits
– recreation (hunting, fishing, camping)
– getting out into the woods
– ecotourism
• Intrinsic Value
– species should be allowed to exist without having to
provide a reason
What are the root causes of
?
• Population growth
• economic policies that do not support
the environment
• high per capita resource use leading to
degradation of the environment
• poverty
What are the direct causes of
?
•
•
•
•
•
•
•
Habitat loss and fragmentation
Hunting and poaching
Overfishing
Predator and pest control
Capture and sale of exotic plants and animals
Climate change and pollution
Introduction of nonnative species
HABITAT LOSS, DEGRADATION,
AND FRAGMENTATION
• Reduction in
ranges of four
wildlife species,
mostly due to
habitat loss and
overharvest.
Figure 11-8
INVASIVE SPECIES
Kudzu vine was introduced in
the southeastern U.S. to
control erosion. It has taken
over native species habitats.
• Many nonnative
species provide us with
food, medicine, and
other benefits but a a
few can wipe out
native species, disrupt
ecosystems, and cause
large economic losses.
Figure 11-A
INVASIVE SPECIES
• Many invasive species have been introduced
intentionally.
Figure 11-11
INVASIVE SPECIES
• Many invasive species have been introduced
unintentionally.
Figure 11-11
INVASIVE SPECIES
• The Argentina fire
ant was introduced
to Mobile, Alabama
in 1932 from South
America.
– Most probably from
ships.
– No natural predators.
Figure 11-12
INVASIVE
SPECIES
• Prevention is the
best way to reduce
threats from invasive
species, because
once they arrive it is
almost impossible to
slow their spread.
Figure 11-13
POPULATION GROWTH,
POLLUTION, AND CLIMATE
CHANGE
• Population growth, affluenza, and pollution
have promoted the premature extinction of
some species.
• Projected climate change threatens a
number of species with premature
extinction.
Pollution
• Each year pesticides:
Example of biomagnification
of DDT in an aquatic food
chain.
– Kill about 1/5th of the
U.S. honeybee colonies.
– 67 million birds.
– 6 -14 million fish.
– Threaten 1/5th of the
U.S.’s endangered and
threatened species.
Figure 11-15
OVEREXPLOITATION
• Some protected species are killed for their
valuable parts or are sold live to collectors.
• Killing predators and pests that bother us or
cause economic losses threatens some
species with premature extinction.
• Legal and illegal trade in wildlife species
used as pets or for decorative purposes
threatens some species with extinction.
OVEREXPLOITATION
• Rhinoceros are
often killed for their
horns and sold
illegally on the
black market for
decorative and
medicinal purposes.
Figure 11-16
Case Study:
Rising Demand for Bushmeat
in Africa
• Bushmeat hunting
has caused the local
extinction of many
animals in West
Africa.
• Can spread disease
such as HIV/AIDS
and ebola virus.
Figure 11-17
Solutions: Protecting Wild Species
from Depletion and Extinction
 Bioinformatics
 International Treaties: CITES
 National Laws: Lacey Act
Endangered Species Act
 Habitat conservation plans
 Wildlife refuges and protected areas
 Zoos, botanical gardens, and gene banks
Regulations - International
• CITES - Convention on the
International Trade of Endangered
Species
– signed by 169 countries to date
– prohibits the trade of live specimens
or products of 900 species on list
Regulations - National
• Endangered Species Act of 1973
– illegal to import or trade in products of species unless
used explicitly for science
– federal government is responsible for management
– the species on the list cannot be “taken”
• threatened, killed, harmed, habitat can’t be harmed
– projects can not be developed which harm species
– requires the development of a recovery plan
• how species can be improved and delisted
– 1200 species listed (4000 candidate species)
• Only 7 have been delisted
Wildlife Management
Laws regulating hunting and fishing
Harvest quotas
Population management plans
Improving habitat
Treaties and laws for migrating species