Pages 183-205

1. Pages 183-205

2. Plate Tectonics • Rift Valleys • Rift Valleys are created by continental plates that drift apart. They typically for deep lakes, seas, or new lands. • The new lands and bodies of water drive speciation. • Hot Spots • Not actually made by continental plates, but rather magma that breaks through the ocean crust. • However movement of plates over hot spots can create chain of islands.

3. Ecosystem Stability and Succession • Organisms cancolonize isolated areas by: • Air • Sea • Animal

4. Specific Types of Dispersal • Jump Dispersal • Long-distance dispersal to remote area by few individuals. • Diffusion • Spread of a species from the edge of their range into a new area • Secular Migration • Dispersal over long time period. Evolutionary changes to species while diffusing into new area.

5. Process of Primary Succession • Primary Succession- The formation of an ecosystem from bare rock. • Pioneer species arrive and colonize bare rock. Soil is created when species die. • New plant growth changes environment. • Plants needing soil arrive, using their roots to retain the soil. • Physical conditions change again • New species arrive (more complex and larger). • Animals arrive in search of food sources. • Climax community is reached.

6. Secondary Succession • Succession that occurs in an area that already has soil. • Can be caused by human activities or natural processes (natural disasters). • Succession can be halted at any time and the climax community may not be reached. • A Sereis the set of communities that succeed one another over the course of succession at a given location.

7. Disturbance • Three factors determine the ability of an ecosystem to recover after an disturbance: • Inertia- or persistence, resistance to being altered, • Resilience- ability of a system to recover after a disturbance, • Diversity- the number and proportions of species present.

8. Disturbance Contin. • A complex ecosystem that has complex food webs allow animals and plants to respond to disturbances in many ways, thus providing an high inertia. • Ecosystems with high resilience have nutrient-rich soils, which promote new growth.

9. Case Study Disturbance of Grass Prairie • The tall grass prairie in the US provided a high diversity, complex ecosystem that maintained stability. • The prairie would recover quickly following fires because of the high build up of organic matter. • Farming has replaced the native ecosystem, causing low diversity, inertia, and soils that need to be maintained artificially.

10. Evaluating Biodiversity and Vulnerability 4.2 page 187

11. Loss of Diversity • Natural disasters have lead to periods of diversity loss in the past. • Changes in Earth’s orbit and tilt and plate movements have lead to repeated long-term cold periods.

12. Factors of Diversity Loss • Natural disasters • Habitat degradation • Agricultural practices • Introduction of non-native species • Hunting, collecting, and harvesting

13. Tropical Rainforest • Consists of emergent layer, canopy layer, understory layer, ground layer. • Considered “biodiversity hotspot” • 50% of plant species, 42% terrestrial vertebrates. • Deforestation • Some species live in the upper layer for entire life e.g.. Rhacophorus gadingensis (tree frog) • Thin, nutrient-poor soils • Difficult to regrow (sometimes!)

14. Green Politics • An ideology which places an importance on ecological and environmental goals. • Through broad-based, grassroots, and participatory democracy. • Stimulated in part by the threats to rainforests. • Principle goal- to obtain sustainable development by reducing deforestation and encouraging reforestation. • Anti-capitalism an important feature

15. Present and Past Extinctions • There have been five mass extinctions • Mass extinction- a large proportion of the total number of species on the Earth at one time are wiped out. • Earth is undergoing the sixth mass extinction, believe to be caused by human activities.

16. Extinctions • Cretaceous-Tertiary (65 million years ago) • End Triassic (199 – 214 million years ago) • Permian-Triassic (251 million years ago) • Late Devonian (364 million years ago) • Ordovician-Silurian (439 million years ago) • Impact of an asteroid or gradual climate change and flood-like eruptions. • Massive floods of lava • Largest event, suspected asteroid or flood volcanism. • Unknown cause. • Drop in sea levels as glaciers formed and then rising sea levels as glaciers melted.

17. Our Current Situation • The evolution of life and the mass extinctions has wiped out 99 percent of all species that have lived on Earth. • Sixth Extinction • First abiotic extinction • Phase 1 began 100,000 years ago when humans dispersed to different parts of the world. • Phase 2: 10,000 years ago when humans turned to agriculture. • Over-population, invasive species, over-exploitation, global warming, pollution • Before 100 species lost per year, now 27,000.

18. Factors that Make Species Prone to Extinction • Small size and limited distribution • Island species • Habitat specialist • Specific diet or habitat requirements • Low reproductive capacity • Live long time • Poor competitors • Lack of mobility or defensive instincts • Large mammals • Significant source of meat and large amounts of resources • Valuable products • Value as pets, ceremonial objects, food • Altruistic species • Preserve bonds to frighten off predators • Clumping • Large numbers • Position of food chain • Higher up = more vulnerability

19. Determining Conservation Status (Red Data Book) • Population size • Queen of the Andes • Reduction in population size • European Eel • Number of mature individuals • Geographic range and degree of fragmentation • Peacock Parachute Tarantula • Quality of habitat • Area of occupancy • Probability of extinction

20. Case Study Extinct Falkland Island Wolf • Ecological Role • Lived in burrows • Diet – ground-nesting birds, grubs, insects, and seashore scavenging. • Pressures • Settlers had sheep which were being killed by the wolves. • Wolf was easily maneuvered into a trap • Consequence of disappearance • Not a significant predator, may have had impact on food chain

21. Critically Endangered: Iberian Lynx • Ecological Role • Specialized feeder (rabbits) and often kill other carnivore species, but does not eat them. • Pressures • Highly specialized diet, small geographic area, habitat destruction. Not allowed to hunt after 1970s. • Methods of restoring population • Public awareness and education programs changed attitudes. Captive breeding program that allow reintroduction into the wild.

22. Improved by Intervention: Bald Eagle • Ecological Role • Live near large bodies of water and have specific territories for nesting. Eat small animals and primarily fish. • Pressures • Population plummeted in 1950s (hunting, pesticides on crops, destruction of habitat, contamination of waterways and food sources, and DDT). • Methods of restoring population • DDT was outlaws in 1970s. • Created Acts for the Eagles and were considered endangered (no hunting).

23. Natural Area Threatened: The Great Barrier Reef • Human threats • Tourism • Over-fishing • Water pollution (fertilizers, pesticides, sewage) • Global warming • Natural threats • Predators and diseases • Storms and cyclones • Coral bleaching • Consequences • Irreversible damage • Loss of biodiversity and valuable role in ecosystem (erosion in mangroves and sea-beds) leads to reduction in its value.

24. 4.3 Conservation of Biodiversity Pages 202-205

25. Arguments for Preserving Species and Habitats • Biodiversity can be difficult to quantify. • Good harvested from the ecosystem are easier to evaluate than indirect values. • Value of the ecosystem depends on cultural background and economic status.

26. Economic Values of Biodiversity • Easy economic value • Natural products • Food • Difficult economic value • Economic productivity • Environmental indicators • Scientific reasons • Education • Genetic diversity • Recreation and ecotourism • Aesthetic value • Human rights • Ethical reasons

27. Conservation Organizations • Non-governmental Organizations (NGOs)- not run by, or funded by, or influenced by governments of any country. Tend to be more radical and field-based. • Intergovernmental Organizations (GOs)- are bodies established through international agreements to protect the environment and bring together governments to work on an international scale. Tend to be more conservative.

28. Conservation Organizations NGO GO • Use of Media • Advertise, leaflets, press packs • Speed of Response • Rapid and regular, own decisions • Diplomatic Constraints • Unaffected by politics, may be illegal • Political Influence • No direct influence • Enforceability • Rely on public pressure, no power to enforce laws • Use of Media • Professional liaison officers, international news clips • Speed of Response • Must meet legal requirements of several countries • Diplomatic Constraints • Cannot give opinion w/out lawyer, disagreements cause serious constraints • Political Influence • Direct access to many countries • Enforceability • Through international agreements and laws

29. International Conventions on Biodiversity • IUNC (World Conservation Union), concerned with conservation of resources for sustainable economic development, has three agendas: • Maintaining ecological processes • Preserving genetic diversity • Using species and ecosystems in a sustainable fashion.

30. International Conventions on Biodiversity • IUNC established World Conservation Strategy, which outlined series of global priorities for action and recommended that account the conservation of natural resources for long-term human welfare. • Drew attention to a fundamental issue: the importance of making the users of natural resources become their guardians. • Stressed that without understanding the local community and support, the strategies cannot succeed.