Download Chapter 12 - Mr. Manskopf`s Class

Sustaining Biodiversity: The
Species Approach
G. Tyler Miller’s
Living in the Environment
14th Edition
Modified by Mr. Manskopf
Chapter 12
Edward Abbey
…the love of wilderness is more than a hunger
for what is always beyond reach; it is also
an expression of the loyalty to the earth, the
earth which bore us and sustains us, the only
home we shall ever know, the only paradise
we ever need-if only we had eyes to see.
Original sin, the true original sin, is the
blind destruction for the sake of greed of this
natural paradise which lies around us…
Chapter 12 Key Concepts
 Human effects on extinction rates
 Understanding biodiversity and extinction
 How human activities endanger wildlife
 Preventing extinction
How does a species go
from having billions to
extinct in just one
century…The
Passenger Pigeon
Story.
Extinct in the wild
since 1900 and last
died in the Cincinnati
Zoo 1914.
Section 1 Key Ideas
• What are the 3 types of extinctions?
• What are endangered and threatened species?
• How do biologists estimate the number of
extinctions?
• How are humans impacting extinction rates?
Species Extinction
Local extinction: species no longer found in a
Specific location.
Ecological extinction: when so few are located
they no longer play a role in a ecosystem.
Biological extinction: when species no longer
exists anywhere.
GONE FOREVER!
Endangered and Threatened Species
Endangered species: has so few individuals
it may soon be extinct.
 Threatened (vulnerable) species: declining
numbers mean it may soon become endangered.
Certain characteristics make some species more vulnerable…big, slow,
tasty or have valuable parts (ie. Tusks)
Florida
manatee
Northern spotted
owl (threatened)
Gray wolf
Florida panther
Bannerman's
turaco (Africa)
TNC estimates
1/3rd of 21,000
identified U.S.
animal and plant
species are
vulnerable.
30,000 of the world’s
species and 1,200 in U.S.
are officially endangered.
Characteristics
that make a
species prone to
extinction.
Percent of various types of species endangered.
How do biologists estimate
extinctions
• 99.9% of all species that
ever existed are extinct.
• Extinctions are “normal”
• What is happening for last
few centuries not
“normal”… mass
extinction.
Extinction Rates
 Background (natural) rate of extinction
 Mass
extinction
 Extinction
spasm
Fig. 5-9 p. 96
How do biologists estimate
extinctions
• Hard to figure out
(extinctions take long
time…)
• ID only 1.4-1.8 million of
5-100 million species
Truth: we don’t know how
many species are becoming
extinct.
SPECIES AREA = 90% loss
of habitat = 50% loss of
species
Problems Estimating Extinction Rates
Extinction not easily documented over time
Many species remain unidentified
Little is known about most identified species
Estimating Extinction Rates: Look up for
homework page 228
Species-area relationships
Population viability analysis (PVA)
Minimum viable population (MVP)
Minimum dynamic area (MDA)
How are humans affecting
extinction rates?
Biologists estimate that current
extinction rate is 1,000 to
10,000 times the rate before
humans.
Before humans one species per
million per year (0.0001%)
TODAY: 0.1 to 1%
Between 5,000 and 100,000 per year
depending upon how many
How are humans affecting
extinction rates?
0.1% to 1% seen as
conservative estimate:
1) Likely to increase due to
population and footprint
2) “Hot Spots” under attack
3) Simplifying ,many
ecosystems… monoculture
Estimates 20% of world’s
plants and animals gone by
2030 and 50% by end of
century
How are humans affecting
extinction rates?
• Habitat fragmentation and disturbance leads to more
opportunistic species like weeds, cockroaches, rodents etc.
• Numbers based on limited data
• Precautionary Principle
“To keep every cog and wheel is the first
precaution of inelegant tinkering.”
Section 2 Key Ideas
• Why should we preserve wild species?
• What is the intrinsic value of a species?
Importance of Wild Species
Why should we care if
species go extinct???
Won’t other species evolve
and take their place???
Main Answer: it would likely
to at least 5 million years
for evolution to rebuild the
biodiversity we are likely
to destroy this century…
what about spiritual
answer?
Importance of Wild Species
Instrumental Value: based
upon the usefulness of
species (economic and
ecological)
•
•
•
•
•
•
Food crops
Fuels
Paper
Medicines
Genetic Information
Recreation (eco tourism)
Importance of Wild Species
Why care about bats???
• 950 known species
• Reproduce slowly
• Live in huge colonies
• Feed on insects that may be
harmful
• Distribute seeds or
pollinate trees
• Keystone Species
Unwarranted fear 10 people
in 4 decades in U.S.
Intrinsic Value of Species
Some people believe that
each wild species has
an inherent right to
exist and play its
ecological role no
matter its usefulness.
• Biophilia
• Does that mean all
species???
• What do you think?
Importance of Wild Species
Rebuilding biodiversity is slow
Instrumental value
Genetic information
Eco-tourism
Ecological value
Intrinsic value (biophilia)
Section 3 Key Ideas
• What is the role of habitat
loss and degradation in
species extinction?
• What is the role of habitat
fragmentation?
• How are birds impacted?
Causes of Depletion of Wild Species
Human population growth
Increasing per capita resource use
Endangered centers of biodiversity
Environmental destruction
Spread of opportunistic species
Causes of Premature Extinction of
Wild Species
Fig. 12-6 p. 231
Habitat Loss and Degradation
Greatest threat to species
“HIPPO”
Habitat destruction
Invasive species
Population (humans) growth
Pollution
Overharvesting
Species squeezed into smaller and more fragmented habitat
Habitat Fragmentation
Species are more vulnerable to
extinction when their habitats
are divided into smaller and
more isolated patches.
• Harder to reproduce
• More vulnerable to predators
• Vulnerable to diseases
• Vulnerable to catastrophic
events (fires, etc.)
• Difficulty finding food, shelter
etc.
Bird Extinctions
• 70% of world’s 9,800
known bird species are
declining
• 1/6 endangered
• Habitat loss and
fragmentation
• Nonnative species (cats
eating birds, rats and
snakes)
• Pet trade (parrots)
Bird Extinctions
• Hooked on fishing lines
• Collide with powerlines,
skyscrapers, wind turbines
• Oil spills
• Pesticides
• Swallow lead from bullets
Bird Extinctions
Environmental indicators:
because they live in every
climate and biome, are easy to
track and respond to changes
quickly
Important:
• Pollination
• Control pests
• Spread seeds
Section 4 Key Ideas
• What is the role of deliberately introduced
species?
• What is the role of accidentally introduced
species?
• How can the threat of nonnative species be
reduced?
• Deer population case study
Nonnative Species Deliberately
Introduced
We depend upon nonnative
species for:
• Economic systems
• Food
• Shelter
• Medicine
• Aesthetics
Corn, wheat, rice, livestock, etc.
(98% of food supply in U.S.)
Nonnative Species Deliberately
Introduced
PROBLEM: When compete,
control or destroy native
species.
• Throws off ecosystem
balance
• 50,000 nonnative species
in U.S.
• Compete for resources
• No predators
Nonnative Species Deliberately
Introduced
Nonnative (Invasive)
species 2nd leading
cause of extinctions
95% in Hawaii
Cats kill estimated 568
million birds in U.S. per
year
Animals and Plants
Deliberately
introduced species
Accidentally
Introduced Species
Page 235
Accidentally Introduces Species
Growing Number of Accidentally
Introduced Species Causing:
• Economic Damage
• Ecological Damage
•
•
•
•
Aircraft
Ballast Water
Cargo
Soil in car tires
Prevention Best To Reduce Threats
Accidentally Introduces Species
Accidentally Introduces Species
California Agriculture Checkpoint
Accidentally Introduces Species
Fig. 12-12 p. 238
Threats from Nonnative Species
Arrival
Roles of nonnative species
Prevention
Examples
(p. 235)
See Case Study
p. 237
Fig. 12-12 p. 238
Section 5-6 Key Ideas
• What is the threat from poaching and hunting?
• Case study: Bushmeat
• What are other threats to endangered species?
• CNN Video
Bushmeat: such as
gorilla head
Source of protein for
local populations
Sometimes sold
internationally
Other Extinction Threats
Hunting and Poaching
Predators and Pest Control
Exotic Pets and Decorative Plants
Climate Change and Pollution
Section 7 and 8 Key Ideas
• How can laws protect species…both internationally and
in the U.S.?
• What are critical habitat designation and recovery plans?
International Laws and Treaties
1975 Convention on
International Trade in
Endangered Species
(CITES)
• 160 countries
• 900 species
• Illegal to trade wildlife
specimens
• Limited success (varies
by country)
U.S. Laws
1900 Lacey Act: prohibits
transporting wild
animals across state
lines
1973 Endangered Species
Act (ESA): one of the
world most far reaching
controversial
environmental laws
U.S. Laws
ESA:
• US Fish and Wildlife
Service (on land) National
Marine Fisheries Service
(in water)
• ID and LIST Endangered
and Threatened species in
need of help
• Must be based on
biological factors
ALONE… no economic or
political
U.S. Laws
ESA:
• Forbids any U.S.
Government funding or
involvement that would
hurt species or habitat
• Private landowners fine
up to $100,000 and
imprisonment
• Illegal to sell or buy
product made from
species
• Can not be hunted, killed
or injured
U.S. Laws
ESA:
• 1973-2004: 92 to 1,260
species listed
• 37 Species removed (14
recovery, 8 extinctions,
rest discovered more)
• 60% plants, 40% animals
• TNC says 1/3rd of all
U.S. species…30,000 not
1,260
Critical Habitat Designation
ESA:
• Requires protecting
critical habitat
• Developing recovery
plan
Lack of funding inhibit
some plans (1/3rd of
species have plan)
2001 Bush stopped
listings
Private Property Rights
Should the U.S.
government compensate
landowners when
Endangered species
decreases the economic
value of their land?
Arguments Yes and No:
Read pages 242-243
Private Property Rights
How can the government
encourage private
landowners to protect
species?
• National Association
of Homebuilders…
How to Avoid ESA
issues
• Habitat Conservation
Plans
Protecting Wild Species: The
Research and Legal Approaches
 International Treaties: CITES and CBD
 U.S. National Laws: Lacey Act
Endangered Species Act
 Habitat recovery plans
Endangered Species Act
Private versus public poverty rights
Win-win compromises
Weaken or strengthen the Act?
Protecting Wild Species: The
Sanctuary Approach
 Wildlife refuges and protected areas
 Gene banks, botanical gardens, and farms
 Zoos and Aquariums
Reconciliation Ecology
 Establishing and maintaining new habitats
 Being good neighbors to wildlife
 Reward voluntary conservation efforts
See Case Study p. 248
Conservation: What Can I Do?
Fig. 12-16 p. 249
Extinction Hot
Spots