Section 5.1 Summary – pages 111-120

1. Biological Diversity Section 5.1 Summary – pages 111-120 • Biodiversity refers to the variety of species in a specific area. • The simplest and most common measure of biodiversity is the number of different species that live in a certain area. • Think Pair Share: Identify the area with the most/least biodiversity

2. Where is biodiversity found? Section 5.1 Summary – pages 111-120 • Think Pair Share: what part of the planet would you expect to find the most biodiversity? The least?. • Areas around the world differ in biodiversity. • Biodiversity increases as you move toward the equator.

3. Where is biodiversity found? Section 5.1 Summary – pages 111-120 • Tropical regions contain two-thirds of all land species on Earth. • The richest environments for biodiversity all seem to be warm places: tropical rain forests, coral reefs, and large tropical lakes.

4. Importance to nature Section 5.1 Summary – pages 111-120 • Living things are interdependent. • Living things can be niches for other living things. • Populations are adapted to live together in communities.

5. Importance to nature Section 5.1 Summary – pages 111-120 • Scientists now know that if a species is lost from an ecosystem, the loss may have consequences for other living things in the area.

6. Biodiversity brings stability Section 5.1 Summary – pages 111-120 • More biodiversity = more stability. • A pest could destroy all the corn in a farmer’s field, but it would be more difficult for it to destroy all the corn (or representative species) in a rain forest.

7. Importance to people Section 5.1 Summary – pages 111-120 • Humans depend on other organisms for their needs. • only a few species of plants and animals supply the major portion of the food eaten by the human population. • Biodiversity could help breeders produce additional food crops.

8. Importance to people Section 5.1 Summary – pages 111-120 • Preserving biodiversity ensures there will be a supply of living things, some of which may provide future drugs. Penicillium

9. Loss of Biodiversity Section 5.1 Summary – pages 111-120 • Extinction: disappearance of a species when the last of its members dies. • a natural process Earth has had several mass extinctions during its history.

10. Loss of Biodiversity Section 5.1 Summary – pages 111-120 • always a level of natural extinction (background extinction) • estimated that background extinction ~ 1 – 10 species/yr. • !! current rate exceeds that by many times.

11. Loss of Biodiversity Section 5.1 Summary – pages 111-120 • endangered species:when numbers so low extinction is possible.

12. Loss of Biodiversity Section 5.1 Summary – pages 111-120 • When a species is likely to become endangered, is threatened.

13. Threats to Biodiversity Section 5.1 Summary – pages 111-120 • One biggest reasons for decline in biodiversity. Habitat loss

14. Section 5.1 Summary – pages 111-120 Habitat fragmentation • the separation of wilderness areas from other wilderness areas.

15. Habitat fragmentation Section 5.1 Summary – pages 111-120 Habitat fragmentation contributes to: • increased extinction. • changes in biodiversity. • disruption of ecological processes. • invasions by exotic species. • risk of fire.

16. Habitat fragmentation Section 5.1 Summary – pages 111-120 • smaller fragment = less biodiversity. • Geographic isolation can → genetic isolation. • makes recolonizing difficult.

17. Edge effect Section 5.1 Summary – pages 111-120 • Conditions at the edge of a habitat are different from those within. • Organisms might be exposed to new organisms or abiotic conditions (predators, prey, temperature, light, plant life) • When an edge changes, animals might migrate because there isn’t enough space from which to gather food.

18. Habitat degradation Section 5.1 Summary – pages 111-120 • habitat degradationthe damage to a habitat by pollution. • air, water, & land. • Pollutants enter atmosphere in many ways—volcanic eruptions, forest fires.

19. Habitat degradation Section 5.1 Summary – pages 111-120 • Burning fossil fuels is source of air pollutants like sulfur dioxide. • Acid precipitation—rain, snow, sleet, and fog with low pH values—linked to damage of forests and lakes.

20. Habitat degradation Section 5.1 Summary – pages 111-120 • ozone layerabsorbs sun’s ultraviolet waves reducing the UV radiation reaching Earth’s surface. Click image to view movie. • synthetic chemicals like chlorofluorocarbons (CFC’s) react with ozone to create “holes” in its layer.

21. Water pollution Section 5.1 Summary – pages 111-120 • Water pollution degrades aquatic habitats in streams, rivers, lakes, and oceans. • can affect aquatic life.

22. Water pollution Section 5.1 Summary – pages 111-120 • Excess fertilizers and animal wastes are carried by rain into streams and lakes. • The sudden availability of nutrients causes algal blooms, the excessive growth of algae, which decreases oxygen levels.

23. Land pollution Section 5.1 Summary – pages 111-120 • solid waste, cans, bottles, paper, plastic, metals, spoiled food, cleaners, or paint may contain chemicals that leach into soil and ground water. • Solution: Recycling Click image to view movie.

24. Land pollution facts Section 5.1 Summary – pages 111-120 • The average American produces ~ 1.8 kg of solid waste daily. • ~ 657 kg of waste/person/yr. • some may decompose, most becomes solid waste buried in landfills.

25. Land pollution Section 5.1 Summary – pages 111-120 • The use of pesticides and other chemicals can also lead to habitat degradation.

26. Exotic species Section 5.1 Summary – pages 111-120 • People may introduce a new species to an ecosystem. • can cause problems for native species. Kudzu

27. Exotic species Section 5.1 Summary – pages 111-120 • When exotic species are introduced, can grow faster because are not as vulnerable to local competitors or predators as native species. • Example: exotic snakes in Florida

28. Section 1 Check Question 1 The term that refers to the variety of species in a specific area is _________. A. ecology B. conservation biology C. biodiversity D. endangered species

29. Section 1 Check The answer is C. The simplest measure of biodiversity is the number of different species that live in a certain area.

30. Section 1 Check Question 2 Describe the possible effect on a biological community of removing one species.

31. Section 1 Check Because living things are interdependent, removing a single species from a community can remove a food source or otherwise break symbiotic relationships causing remaining organisms to suffer. This decreases the stability of the ecosystem.

32. Section 1 Check Question 3 When the population of a species begins to significantly decline in numbers, it is __________. A. threatened B. extinct C. fragmented D. diverse

33. Section 1 Check The answer is A. When the population of a species is declining and likely to become endangered, it is said to be a threatened species. Results of Species Search* Current Range Scientific Name Group Listing status Common Name Mammals T Africa African elephant Loxodonta africana *U.S. Fish & Wildlife Service Threatened and Endangered Species System (TESS) Through the Fish and Wildlife Service, information is available to the public on all species threatened or endangered T, under Listing Status, refers to threatened. An E would indicate endangered.