Chapter 10: Biodiversity p. 240-258
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Transcript of Chapter 10: Biodiversity p. 240-258
Chapter 10: Biodiversityp. 240-258
1. What is biodiversity?2. Biodiversity at Risk
3. The future of Biodiversity
Key Terms
• Biodiversity• Gene• Keystone species• Ecotourism• Endangered species• Threatened species
• Exotic species• Poaching• Endemic species• Germ plasm• Endangered species act• Habitat conservation
plan• Biodiversity treaty
objectives• Describe the diversity of species types on Earth,
relating the difference between know numbers and estimated numbers.
• List and describe 3 levels of biodiversity.• Explain 4 ways in which biodiversity is important
(benefits) to ecosystems and humans.• What are some medical examples? • Analyze the potential value of a single species.
(Keystone) Give an example.
What is biodiversity?- Biological Diversity(number and variety of species in an
area)
• What causes species to become extinct?• How many species are becoming extinct?• How much extinction is natural?• Do you think humans should try to prevent the
loss of species? If we study other organisms and preserve
biodiversity helps us for our own survival.
Unknown Diversity-• Haven’t discovered yet• Deep in ocean, remote wilderness• Know more about trees and animals• Less about insects and fungi
Levels of Diversity1. Species diversity- all the differences between
populations of species, as well as between different species
2. Ecosystem diversity- variety of habitats, communities and ecological processes within and between ecosystems
3. Genetic diversity- different genes contained within all members of a population
Benefits of Biodiversity1. Impact the stability of ecosystems and
populations2. Healthy ecosystems to ensure healthy
biosphere3. Increase in genetic diversity (no bottlenecking)4. Medical and Agricultural5. Ethics, Aesthetics and Recreation (ecotourism)
Keystone Species
Sometimes changes in the population of a single species, often called a keystone species, can cause dramatic changes in the structure of a community. – In the cold waters off the Pacific coast of North America, for example, sea otters devour
large quantities of sea urchins.
– Urchins are herbivores whose favorite food is kelp, giant algae that grow in undersea “forests.”
– A century ago, sea otters were nearly eliminated by hunting. Unexpectedly, the kelp forest nearly vanished.
– Without otters as predators, the sea urchin population skyrocketed, and armies of urchins devoured kelp down to bare rock.
– Without kelp to provide habitat, many other animals, including seabirds, disappeared.
– Otters were a keystone species in this community.
Ecology 2010
Biodiversity at risk- objectives • Define and give examples of endangered and threatened species. • Describe several ways that species are being threatened with
extinction globally. What are the humans doing?• What are exotic species? Give an example.• Explain poaching? How does this affect the biodiversity?• Explain which types of threats are having the largest impact on
biodiversity.• List areas of the world that have high levels of biodiversity and many
threats to species.• What are endemic species? Give an example.• Compare the amount of biodiversity in the US to that of the rest of
the world.
Current Extinctions• Past: Most extinctions are mass due to climate
change (natural)• Current: Between 1800 and 2100 25% of all
species on earth may become extinct due to humans (not natural)
Species prone to extinction- small populations in limited areas, small gene pool, migrate, need large or special habitats, exploited by humans
Species prone to extinction-
• Endangered species- likely to happen if protective measures are not taken immediately
• Threatened species- has declining population and that is likely to become endangered if it is not protected
Human Impact?Population growth accelerated and so has rate
of extinctions (table 3 p. 246)1. Destruction of habitats and fragmentation2. the introduction of nonnative species
(Invasive Exotic species)3. Harvesting, hunting, and poaching4. Pollution
Human Impact?1. Destruction of habitats and
fragmentation - Almost 75% of extinctions now occurring- 2001 Florida Panther 80 left
Human Impact?2. the introduction of nonnative
species -Invasive Exotic species – species that is not
native to a particular regionCan threaten native species have no natural
defenses against themHawaii strict rules of brining in plants and fruits-(fire ants, zebra muscles, many plants)
Human Impact?3. Harvesting, hunting, and poaching- 1800s- to 1900s 2 billion passenger pigeons
were hunted to extinction and bison was hunted nearly to extinction
- Pets, house plants, wood ,food, medicine- New laws to regulate hunting, fishing,
harvesting, trade- Poaching- illegal trade of regulated wildlife
Human Impact?4. Pollution-Pesticides, cleaning agents, drugs are making
their way into food webs- DDT and bald eagle only illegal to use in us
Areas of Critical Biodiversity
Endemic species- are native to and found only within a limited area
1. Tropical rain Forest2. Coral Reefs and Coastal Ecosystems3. Island-
Tropical Rain Forest• Covers less than 7% of earths land surface• However over half of world’s species live in
these forest• Many have never been identified or described• Unknown numbers of species are
disappearing as tropical forests are cleared for farming
• http://library.thinkquest.org/11353/trforest.htm
Coral Reefs and Coastal Ecosystems
• Also occupy a small fraction of marine environments yet contain the majority of the biodiversity
• Food, tourism revenue, coastal protection, new chemicals
• 1998 study estimated $375 billion per year• 60% reefs threatened by human activities• (nemo)
Island• Colonized by a limited number of species from
mainland (Galapagos and Hawaiian Islands)• Holds very distinct but limited set of species• Hawaii hold 28 species of birds called
honeycreepers
Biodiversity Hotspots• Most threatened areas of high species
diversity• 25 areas- many have lost at least 70% of
original natural vegetation• Madagascar- 18% forest remains, more than
10,000 flowering plant species are endemic91% of 300 reptile33 species of lemur
Biodiversity in US1. Florida Everglades2. California coastal region3. HawaiiUS holds high numbers of species of freshwater
fish, mussels, snails, crayfish, pine trees and sunflowers
California Floristic Province- 3,488 native plants (2,124 are endemic and 565 threatened or endangered) threatened by local human growth
10.3 objectives
• List and describe 4 types of efforts to save individual species.
• Explain the advantages of protecting entire ecosystems rather than individual species.
• Discuss ways in which efforts to protect endangered species can lead to controversy.
• Describe 3 examples of worldwide cooperative effort to prevent extinctions.
• Explain the outcomes of CITES and Biodiversity Treaty.
Future of BiodiversitySlowing the loss of species is possible, but to do
so we must develop new approaches to conservation and sensitivity to human needs around the globe.
Saving on Species One at a Time
1. Captive- Breading Programs2. Preserving genetic material3. Zoos, aquariums, parks and gardens4. More study needed
1. http://www.thehindu.com/sci-tech/energy-and-environment/article3568516.ece
Captive-Breeding Programs
• Breeding species in captive in hopes to restore populations
• California Condor- Scavengers, habitat loss, poaching, led poisoning
• 1986- 9 remaining left as of 2002 58 condors returned to wild and 102 still live in captivity
• But will they reproduce in the wild to restore their populations
Preserving Genetic Material• Germ Plasm- any form of genetic material that
can reproduce to produce new lifeSeeds, sperm, eggs or DNA• Germ-Plasm banks- store for future use of
research
Zoos, Aquariums, Parks and Gardens
• Original was to put exotic animals on display• Now house few remaining organisms• Botanical gardens house about 90,000 species
of plants worldwide
More study needed• Saving a few individuals does little to preserve
a species• Captive species may not reproduce or survive
again in the wild (Lonesome George)• Vulnerable to infectious disease and genetic
disorders caused by inbreeding• Last resort to save species
Preserving Habitats and Ecosystems
• Number one way to save species is to protect their habitats
• More than just a small plot of land1. Conservation Strategies- protect the
ecosystems rather than the individual speciesMain focus is on world hot spotsMore study is needed for preservation
Legal Protection• US Laws- – 1973 US Congress passed Endangered Species Act
(p255 table 4) protect plant ad animal species in danger of extinction
– USFWS must compile a list– May not be caught or killed, not uprooted, sold or
traded– No project can jeopardizes endangered species– Must prepare a species recovery plan for each
Recovery and Habitat Conservation Plan
• Can be controversial for human use• Habitat conservation plan- attempts to protect
one or more species across large area of land through trade-offs or cooperative agreements
International Cooperation• International Union for the Conservation of
Nature and Natural Resources (ICCN)- try to protect species and habitats
• 200 governmental agencies and over 700 private conservation organizations
• Red List of species in danger ww• Advised governments on ways to manage natural
resources and work with groups life World Wildlife Fund to sponsor conservation projects
International Trade and Poaching• CITES- Convention on International Trade in
Endangered Species• Fist effective effort to stop the slaughter of
African elephants (poaching for Ivory)• Biodiversity Treaty- Earth Summit- 100 world
leaders 30,000 other participants met in 1992 in Rio de Janeiro, Brazil- Treaty goal was to preserve biodiversity and ensure that sustainable and fair use of genetic resources in all countries
Private efforts- • World Wildlife Fund • Nature Conservancy• Greenpeace
Balancing Human NeedsAttempts to protect species often come into conflict
with the interest of the world’s human inhabitants. Sometimes, an endangered species represents a source of food or income, in other cases, a given species may not seem valuable to those who do not understand the species role in an ecosystem
Many conservationists feel that an important part of protecting species making the value of biodiversity understood by more people.