1. Biology Chapter 5, Section 1
Vanishing Species
Biology Chapter 5, Section 1

2. Biological Diversity
A rainforest has a greater amount of biological diversity than a cornfield.
Biodiversity: refers to the variety of species in a specific area.
Easiest way to think about this is how many different species live in a specific area.

3. Where is Biodiversity Found?
Areas around the world differ in biodiversity.
Biodiversity increases as you travel toward the equator.
Tropical regions contain two-thirds of all land species on Earth.
Richest environments for biodiversity all seem to be warm places: tropical rain forests, coral reefs, and large tropical lakes.

4. Studying Biodiversity
The studying of islands has led to an understanding of factors that influence biodiversity.
Many tests have helped scientists discover that the larger the island, the more habitats and species seemed to have, implying that the number of species depends on the number of habitats.

5. Importance of Biodiversity
THINK: Compare a parking lot to your backyard.
What sorts of organisms are present in each scenario?
Do these numbers matter?
Why or why not?

6. Importance to Nature Living things are interdependent
Animals cannot live without green plants.
Many plants need animals to pollinate them.
Plants are also dependent on decomposers to break down dead/decaying materials so they can access the materials for life.
Populations are adapted to live together in communities.
With this knowledge, what happens when a species leave a community or goes extinct?

7. Biodiversity brings stability
Ecosystems are stable if their biodiversity is maintained.
A change in species can destabilize a community.

8. Importance to people Humans depend on organisms for their needs.
We need to eat!!!
People also rely on the living world for raw materials used in clothes, furniture, and buildings.

9. Importance to people
Humans also need biodiversity of the world for health reasons.
Living things supply the world pharmacy.
Although drug companies manufacture synthetic drugs, active compounds in these drugs are usually first isolated from living things.
Preserving biodiversity ensures there will be a supply of living things, some of which may provide future drugs.

10. Loss of Biodiversity Have you ever seen a woolly mammoth in person?
Extinction: is the disappearance of a species when the last of its members die.
Extinction is a natural process and the Earth has experienced mass extinctions several times.
Scientists hypothesize that the expanding human population, habitat loss, and land exploitation have given rise to the increase of species extinctions.

11. Loss of Biodiversity
Endangered species: a species is considered this when its numbers become so low that extinction is possible.
When species are likely to become endangered, they are known as threatened species.
The US Fish and Wildlife Service maintains a listing of threatened and endangered species for the US and the world.

12. Threats to Biodiversity
Complex interactions among species make each ecosystem unique.
Changes to habitats can therefore threaten organisms with extinctions.

13. Habitat Loss
One of the biggest reasons for decline in biodiversity is habitat loss.
Much of the rainforests have been cut down for farmland and firewood.
Clearing this land erased habitats that cannot be reestablished.
Coral reefs are also killed each year by humans.
Disease and water temperature can damage or kill coral.
As coral habitats are lost, species of fishes and other organisms are lost with it.

14. Habitat Fragmentation
Habitat fragmentation: is the separation of wilderness areas from other wilderness areas.
Fragmentation can lead to:
Increased extinction of local species
Disruption of ecological processes
New opportunities for invasions by introduced or exotic species
Increased risk of fire
Changes in local climate

15. Habitat Fragmentation
These areas are similar to islands
The smaller the fragment, the less biodiversity the area can support.
As species migrate from an area that has become unsuitable, other species that depend on these species lose their life support.
As a result, the overall species diversity declines.
Geographic isolation can lead to genetic isolation.
No chance for breeding to happen in smaller areas.

16. Habitat Fragmentation
Problems that arise from fragmentation:
Large predators cannot be supported
Food and space is restricted
Reestablishing a species is difficult

17. Edge Effect
The edge of a habitat or ecosystem is where one habitat or ecosystem meets another one.
The different conditions along the boundaries of an ecosystem are called edge effect.
Edges tend to have greater biodiversity because different habitats with different species are brought together.
When an edge changes, animals from one area migrate from the area or move to the new edge, thereby “mixing” the ecosystem.

18. Habitat Degradation
Habitat degradation: the damage to a habitat by pollution.
There are three types of pollution: air, water, and land.
Air pollution can cause breath problems and irritate membranes in eyes/nose.
Burning fossil fuels is also a major source of air pollutants.

19. Habitat Degradation
Acid precipitation: rain, snow, sleet, fog with low pH values, has been linked to deteriorations of some forests and lakes.
Acid precipitation damages plant tissues and interferes with plant growth.
Lake ecosystems are affected through runoff and rain which causes the pH to fall.

20. Habitat Degradation
Ultraviolet waves emitted by the Sun also can cause damage to living organisms
Ozone is a compound of three oxygen atoms found in the Earth’s atmosphere.
The ozone layer absorbs some of the ultraviolet waves striking the atmosphere, reducing the ultraviolet radiation reaching Earth’s surface.

21. Water Pollution
Water pollution degrades aquatic habitats in streams, rivers, lakes, and oceans.
Excess fertilizers and animal wastes contribute to water pollution.
Nutrients are available to algae, which causes excessive growth.
Excessive growth leads to more oxygen used from the water and decaying algae to sink.
Pollutants such as detergents, heavy metals, and industrial chemicals in runoff also harm organisms living in the water.
Old fishing nets have also been known to harm whales, dolphins, etc.

22. Land Pollution
The average American produces about 1.8kg of solid waste daily/657kg per year
What happens to the trash YOU throw out???
Landfills have strict controls on design, construction, and placement of landfills to help reduce contamination of groundwater supplies.

23. Land Pollution
Pesticides and other chemicals can lead to habitat degradation.
DDT was used for many years to control and kill mosquito larvae.
Birds fed on plants and insects infected with DDT which caused their egg shells to be too fragile.
This caused the population of bald eagles to decline significantly.

24. Exotic Species
Sometimes new species are introduced into an ecosystem intentionally/unintentionally.
This can be a problem to already existing species.
Exotic species: are not native to a particular area and have no known predators.
When these exotic species are introduced into an ecosystem, they grow at an exponential rate and eat the species native to the area causing the populations to decline.

25. Conservation of Biodiversity
Biology Chapter 5, Section 2

26. Conservation Biology
Conservation Biology: is the study and implementation of methods to protect biodiversity.
Scientists use strategies based on ecology to help save organisms.
Natural Resources: are those parts of the environment that are useful or necessary for living organisms.
Sunlight, water, air, plant/animal resources

27. Legal Protections of Species
With concerns about species extinction, the US Endangered Species Act became a law in 1973,
This law made it illegal to harm any species on the endangered or threatened lists, and for federal agencies to fund any project that would harm organisms on the list.
Worldwide, Convention on International Trade in Endangered Species (CITES) has est. lists of species for which international trade is prohibited or controlled.

28. Preserving Habitats
One way habitats have been preserved is through the protection/creation of national parks.
Yellowstone National Park was created in 1972
Originally created to protect the unique geology but soon was proven to be home to species of bear, bison, moose, and elk.

29. Habitat Corridors
Is it better to protect one large piece of land or several smaller, disconnected pieces of land?
There are two schools of thought:
Protect the largest amount of land possible
Connect protected areas with habitat corridors.
Habitat corridors: protected strips of land that allow the migration of organisms from one wilderness area to another.
Proven to help overcome some effects of habitat destruction and is beneficial to plants/animals.

30. Working with People
Rangers are hired to monitor national parks to make sure people are not breaking the law and harming organisms.
The philosophy of sustainable use strives to enable people to use natural resources in ways that will benefit them and maintain the ecosystem.
Sustainable use allows people to make a living and the ecology of the area is maintained.

31. Reintroduction and species preservation programs
Reintroduction programs introduce organisms into an area where the species once lived.
The most successful programs have been when organisms are taken from an area in the wild and transported to a new habitat.

32. Captivity
Some species no longer exist in the wild, but a small number of individual organisms is maintained by humans.
Captivity: organisms that are housed by people.

33. Protecting Plant Species
The ideal way to protect a plant species is to allow it to exist in a natural ecosystem.
Seeds can be cooled and saved for later reintroduction.