Transcript ES Unit 10 Biodiversity

Biodiversity
Unit 10
Standards
• SEV.5a Describe factors affecting population
growth of all organisms, including humans.
Relate these to factors affecting growth rates
and carrying capacity of the environment.
• SEV.5f Describe how political, legal, social,
and economic decisions may aect global and
local ecosystems.
A World Rich in Biodiversity
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Biodiversity (biological diversity):
-variety of organisms in a given area
-genetic variation within a population
-variety of species in a community
-variety of communities in an ecosystem.
• Humans need to understand and preserve
biodiversity for our own survival.
Unknown Diversity
• Number of species: about
1.7 million, most of which
are insects.
• -scientists estimate that there
are more than 10 million
species of organisms (actual
number of species is unknown).
Unknown Diversity
Unknown Diversity
• -New species are considered
known when they are
collected and described
scientifically.
• -Unknown species exist in
remote wilderness, deep
oceans (even in cities).
• -Some species are harder to
study and receive less
attention than large, familiar
species.
Levels of Diversity
• Biodiversity can described at three levels:
• -species diversity: differences between
populations of species.
• -ecosystem diversity: variety of habitats,
communities, and ecological processes within
ecosystems.
• -genetic diversity: differences in genetic makeup
within a population.
Genetic Diversity
• Genetic diversity: all the
different genes contained
within all members of a
population.
• -gene is a segment of DNA
located in a chromosome
that codes for a specific
hereditary trait.
Benefits of Biodiversity
• -Affects stability of
ecosystems and the
sustainability of
populations.
• -Ensures a healthy
biosphere with balanced
cycles of energy and
nutrients.
Species Are Connected to Ecosystems
• -Every species is a part of a
nutrient cycle.
• -Every species is either dependent
on or depended upon by at least
one other species.
• -When one species disappears
from an ecosystem, a strand in a
food web is removed.
Keystone Species
• Keystone species: species that is critical to the
functioning of the ecosystem; it affects the survival
and abundance of other species in its community.
Keystone Species
• Sea otter: loss of the sea otter populations led to
an unchecked sea urchin population, which ate all
the kelp leading to the loss of kelp beds along the
U.S. Pacific Coast.
Species are Connected to Ecosystems
• Genetic diversity: increases the
chances that members of a
population may survive
environmental pressures or
changes.
• Small and isolated populations
are less likely to survive..
Species and Population Survival
• -When a population shrinks,
its genetic diversity
decreases- genetic
bottleneck.
• -If such a population is able to
increase again, there will be
inbreeding within a smaller
variety of genes.
• -Inbred organisms may
become more likely to inherit
genetic diseases.
Medical and Industrial Materials
• -One quarter of the drugs prescribed
in the United Sates are derived from
plants
• -Almost all of the antibiotics are
derived from chemicals found in
fungi.
• -Chemicals and industrial materials
may be developed from chemicals
discovered in all kinds of species.
Medical Uses
Benefits of Biodiversity (cont’d)
Species represent a source of
useful chemical and
industrial materials.
Agricultural Uses
• -Most crops originated from a few areas of high
biodiversity.
• -New crop varieties are hybrids developed by
combing genetic material from existing plants.
• -Depending on too few plants for food is risky
due to reduced genetic diversity.
• Ex. Famines have resulted when a major crop was
wiped out by disease. Crossbreeding crop plants
with wild relatives have resulted in hardier plants.
Agricultural Uses
Benefits of Biodiversity (cont’d)
Species should be
preserved for ethical,
religious, or aesthetic
reasons.
Preserving Biodiversity
• -Ethical view: species and ecosystems have a
right to exist whether or not they have any
other value.
• -Aesthetic view: camping, picking flowers, or
watching wildlife.
• -Economic: ecotourism- tourism that supports
the conservation and sustainable
development of ecologically unique areas for
profit.
The Importance of Biodiversity and
You
Human benefits from biodiversity:
-medicines
-industrial material
-agriculture (food!)
-aesthetics (beauty)
-and, again, survival
Biodiversity at Risk
Unit 10; Section 2
Biodiversity at Risk
• Mass extinction: total loss
of many species in a short
period of time.
• -Earth has experienced
several mass extinctions,
each may have been caused
by global climate change.
• -It takes millions of years
for biodiversity to rebound
after a mass extinction.
Biodiversity at Risk
Current Extinctions
• Earth is in the midst of another mass
extinction.
• -Rate of extinctions is estimated to have
increased by a multiple of 50 since 1800
• -Up to 25% of all species will become extinct
between 1800 and 2100.
• -Due to human impact on ecosystems.
Species Prone to Extinction
• -Small populations in limited areas can easily
become extinct.
• -Species that migrate, need large or special
habitats, and those that are exploited by
humans are most at risk.
FYI: Among the Most at Risk Species
FYI: Among the Most at Risk Species
Endangered Species
• Endangered species: in danger of extinction
throughout all or a significant part of its range.
• -under protection by regulations or
conservation measures.
Threatened Species
• Threatened species: likely to become
endangered in the foreseeable future.
Endangered Species Fact Cube
• The are 6 sides to the cube
• Include the following information on your cube. Only
1 piece of info per side!:
-scientific and common name of organism
-picture/drawing of organism
-location and habitat
-interesting fact
-interesting fact
-environmental threats
How Do Humans Cause Extinctions?
• In the past 2 centuries, human population
growth has accelerated and so has the rate of
extinctions.
• The major causes of extinction today are:
• -destruction of habitats
• -introduction of nonnative species
• -pollution
• -overharvesting of species
How Do Humans Cause Extinctions?
Habitat Destruction and
Fragmentation
• As human populations grow,
more land is needed to build
homes and harvest
resources.
• -habitats are destroyed or
fragmented.
• -75% of the extinctions are
due to habitat loss.
Habitat Fragmentation
Habitat Fragmentation
FYI: Case of the Cougar
• Cougars, including the Florida
Panther, require expansive ranges
of forest and large amount of prey.
• Today, much of the cougars’ habitat
has been destroyed or broken up by
roads, canals, and fences.
• In 2001, fewer than 80 Florida
panthers made up the only
remaining wild cougar population
east of the Mississippi River.
Invasive/ Exotic Species
• Exotic species: species not native to a
particular region.
• -can threaten native species that have no
natural defenses against them.
Pollution
• Chemicals used by humans are
making their way into food webs
around the globe.
• -long term effects of chemicals may
not be clear until after many years.
FYI: Case of the American Eagle
• FYI: The bald eagle was endangered because
of a pesticide known as DDT. Although DDT is
now illegal to use in the United States, it is still
manufactured here and used around the
world.
Harvesting, Hunting, and Poaching
• Poaching: illegal harvesting of fish,
game, or other species.
• -Excessive hunting can lead to
extinction as seen in the 1800s
and 1900s when 2 billion
passenger pigeons were hunted to
extinction.
• -Thousands of rare species
worldwide are harvested and sold
for use as pets, houseplants,
wood, food, or herbal medicine.
FYI: Overexploitation
• Rhinoceros are often
killed for their horns
and sold illegally on
the black market for
decorative and
medicinal purposes.
Figure 11-16
FYI: 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
Least Wanted Poster
• NAME: State the latin name and common name (alias) of your
species.
• PICTURE: at least one photograph clearly showing your species.
• IDENTIFYING CHARACTERISTICS: What are the key features to
look for when identifying the criminal?
• LAST SEEN: Where did the species originally come from?
• SUSPECTED HIDEOUTS: Where has your species most recently
been seen (in their new, nonnative environment)? Describe
their preferred habitat and how they got there.
• CRIMES COMMITTED: What are the problems with your species
in their new environment? (Crimes must be specific to your
species and not general to all invasive species.)
• REWARD: what is your reward for the elimination of your
species? Think ecologically and be specific for your species.
• REWARD for finding unwanted biological invaders!
Areas of Critical Biodiversity
• Endemic species: species
native to a particular place and
that is found only there.
• -areas of that contain greater
diversity of species have a large
portion of endemic species.
• -plants are used as an indicator
of overall biodiversity because
plants form the basis of
ecosystems on land.
Tropical Rain Forests
• Over half of the world’s species
live in tropical forests, which cover
only 7 percent of the Earth’s land
surface.
• -most of the species have never
been described.
• -unknown numbers of these
species are disappearing due to
clearing for farming or cattle
grazing.
Coral Reefs and Coastal Ecosystems
• 60 percent of Earth’s coral reefs are
threatened by human activities:
pollution, development along
waterways, and overfishing.
• -reefs provide people with food,
tourism revenue, coastal protection,
new chemicals, but are poorly studied
and not as well protected by laws as
terrestrial areas are.
• -similar threats affect coastal
ecosystems, such as swamps, marshes,
shores, and kelp beds.
Islands
Islands are colonized by a limited
number of species from the
mainland.
-colonizing species may evolve to
several new species.
-islands often have distinct, limited
set of species.
-many island species are endangered
because of invasive, exotic species.
ex. Hawaiian honeycreeper
Biodiversity Hotspots
• Biodiversity hotspots: most threatened areas of
high species diversity on Earth, include mostly
tropical rainforests, coastal areas, and islands.
• -high numbers of endemic species
• -threatened by human activities.
• -most of these hotspots have lost at least 70%
• of their original natural vegetation.
Biodiversity Hotspots
Biodiversity in the United States
• -Unique ecosystems, including the
Florida Everglades, the California
coastal region, Hawaii, the
Midwestern prairies, and the
forests of the Pacific Northwest.
• -holds unusually high numbers of
• species of freshwater fishes,
• mussels, snails, and crayfish.
• -high diversity of the land plants
• such as pine trees and sunflowers.
Biodiversity in the United States
• California Floristic Province: hotspot, home
to 3,488 native plant species.
• -2,124 are endemic
• -565 are threatened or endangered.
• -threats to area include habitat destruction
for agriculture and housing, dam
construction, overuse of water, destructive
recreation, and mining.
The Future of Biodiversity
Unit 7 Section 3
Saving Species One at a Time
• Methods to preserve individual species often
involve keeping and breeding the species in
captivity.
Captive-Breeding Programs
• Captive-breeding programs:
involve breeding species in
captivity, with the goal of
reintroducing populations to their
natural habitats.
• -habitat may no longer exist for
released animals
• -no guarantee that restored
populations will reproduce in the
wild.
California Condor
Californian condor was brought back from the point
of extinction due to captive breeding.
-last free-flying condor was captured in 1987
-currently about 400 condors in the wild
-threats include habitat loss, death of chicks fed
micro-trash
Preserving Genetic Material
• Germ plasm: hereditary material
(chromosomes and genes) that is
contained in the protoplasm of
germ cells
• -may be stored as seeds, sperm,
eggs, or pure DNA.
• -germ plasm banks keep germ
plasm in controlled environments
for future use in research or
species-recovery efforts.
Zoos, Aquariums, Parks, and Gardens
• Zoos, wildlife parks, aquariums,
and botanical gardens, are living
museums of the world’s
biodiversity.
• -facilities rarely have enough
resources to preserve more than a
fraction of the world’s rare and
threatened species.
More Study Needed
• Saving a few individuals does little to
preserve a species as captive species
may not reproduce or survive again
in the wild.
• -small populations are vulnerable to
infectious diseases and genetic
disorders caused by inbreeding.
• -conservationists hope that these
strategies are a last resort to save
species.
Preserving Habitats and Ecosystems
• Most effective way to save species is to
protect their habitats.
• -protecting the habitats requires preserving or
managing large areas.
• (Conserving small plots of land is usually not
enough because a species confined to a small
area could be wiped out by a single natural
disaster or species may require a large range
to find adequate food.)
FYI Conservation Strategies
• Conservationists give priority to
protecting entire ecosystems
rather than individual species.
• -we may be able to save most of
the species in an ecosystem
instead of only the ones that are
endangered.
• -most people have begun to
understand that Earth’s biosphere
depends on all its connected
ecosystems.
Conservation Strategies
• Conservationists focus on the
hotspots to protect biodiversity
worldwide; they also support
additional strategies:
• -identification of native habitat that
can be preserved, restored, and
linked into large networks.
• -promotion of products that have
been harvested with sustainable
practices.
FYI More Study Needed
• Urgent need for more serious study of the
workings of species and ecosystems.
• -Question: How much fragmentation can a
particular ecosystem tolerate?
• -Answer: not enough research has been done
to know
Legal Protection for Species
• Endangered Species Act
(1973): designed to protect any
plant or animal species in
danger of extinction.
U.S. Laws
• Under the first provision of the Endangered Species
Act, the U.S. Fish and Wildlife Service (USFWS) must
compile a list of all endangered and threatened
species in the United States.
• - (2002) 983 species of plants and animals were listed.
• -second main provision of the act protects listed
species from human harm.
• -third provision prevents the federal government from
carrying out any project that jeopardizes a listed
species.
U.S. Laws
Recovery Plans
• Under the fourth main provision of the
Endangered Species Act, the USFWS must
prepare a species recovery plan for each
listed species.
• -plans often propose to protect or restore
habitat for each species.
• -attempts to restrict human uses of land can
be controversial.
• -developers may be prohibited from building
in certain areas, and people may lose
income and may object when their interests
are placed below those of another species.
Habitat Conservation Plans
• Conflict between environmentalists
and developers are widely publicized,
and in most cases, compromises are
eventually worked out:
• -habitat conservation plan: land-use
plan that attempts to protect
threatened or endangered species by
allowing tradeoffs between harm to
the species and additional
conservation commitments among
cooperating parties.
International Cooperation
• The International Union for the
Conservation of Nature and Natural
Resources (IUCN) facilitates efforts to
protect species and habitats.
• -publishes Red Lists of species in danger
of extinction around the world
• -advises governments on ways to manage
their natural resources
• -works with groups like the World Wildlife
Fund to sponsor projects such as
attempting to stop poaching in Uganda.
International Trade and Poaching
• CITES (the Convention on International Trade
in Endangered Species).
• -first effective effort to stop the slaughter of
African elephants being killed by poachers
who would then sell the ivory tusks.
• -in 1989, the members of CITES proposed a
total worldwide ban on all sales, imports,
and exports of ivory.
FYI International Trade and Poaching
• Some people worried that
making ivory illegal might
increase the rate of poaching
instead of decrease it.
• They argued that illegal ivory,
like illegal drugs, might sell for a
higher price.
• But after the ban was enacted,
the price of ivory dropped, and
elephant poaching declined
dramatically.
The Biodiversity Treaty
• The United Nations Conference on Environment
and Development, also known as the first Earth
Summit (1992).
• -resulted in the Biodiversity Treaty: an
international agreement aimed at strengthening
national control and preservation of biological
resources.
The Biodiversity Treaty
• Treaty’s goal is to preserve biodiversity and
ensure the sustainable and fair use of genetic
resources in all countries.
• -treaty took several years to be adopted into law
by the U.S. government.
• -some political groups objected to the treaty,
especially to the suggestion that economic and
trade agreements should take into account any
impacts on biodiversity that might result from the
agreements.
FYI Private Conservation Efforts
• Private organizations work to protect species
worldwide, often more effectively than government
agencies.
• -World Wildlife Fund: encourages the sustainable use
of resources and supports wildlife protection.
• -The Nature Conservancy: purchases millions of
hectares of habitat preserves in 29 countries.
• -Conservation International: helps identify biodiversity
hotspots.
• -Greenpeace International organizes direct and
sometimes confrontational actions.
Balancing Human Needs
• Attempts to protect species often come into
conflict with the interests of the world’s human
inhabitants.
• An endangered species might represent a source
of food or income. Or a given species may not
seem valuable to those who do not understand
the species’ role in an ecosystem.
• Many conservationists feel than an important
part of protecting species is making the value of
biodiversity understood by more people.
Ticket out the Door
1.
2.
3.
4.
What is a captive breeding program?
What is germ plasm?
What is the Endangered Species Act?
When was the Endangered Species Act
passed?
5. What is a habitat conservation plan?
6. What is CITES?
7. What is the Biodiversity Treaty?