009 Biodiversity & Conservation Biology

1. Environment & Ecology 009 Biodiversity & Conservation Biology

2. Central Case: Saving the Siberian tiger

3. Central Case: Saving the Siberian tiger

4. 1950 1982 Probably extinct population

5. Biodiversity encompasses several levels • Humans are diminishing Earth’s diversity of life. • Biodiversity: sum total of all organisms in an area • Split into three specific levels: • Species diversity • Genetic diversity • Ecosystem diversity

6. Species diversity • Species diversity: the number or variety of species in the world or in a particular region • Species richness: the number of species 70 coral species in Hawaii

7. Tiger Classification Kingdom Animalia Phylum Chordata Class Mammalia Order Carnivora Family Felidae Genus Panthera Species tigris

8. Biological Nomenclature A species is both defined by its genus name and specific name. Ex.Panthera tigris Panthera- genus name tigris- species name

9. Lion, Leopard & Tiger Panthera leo Panthera pardus Panthera tigris

10. Biological Species Organisms that are genetically similar, and have ability to interbreed and produce viable, fertile offspring

11. Subspecies: the level below a species • Subspecies: populations of species that occur in different areas and differ slightly from each other Siberian tiger = Panthera tigris altaica Bengal tiger = Panthera tigris tigris All subspecies of tigers have disappeared from 93% of their historic range.

12. Genetic diversity • Encompasses the differences in DNA among individuals within species and populations • Populations with higher genetic diversity can survive. • They can cope with environmental change. • Populations with low genetic diversity are vulnerable. • To environmental change • Disease • Inbreeding depression

13. Genetic diversity • Inbreeding depression: genetically similar parents mate and produce defective offspring

14. Ecosystem diversity • Ecosystem diversity: the number and variety of ecosystems • It also encompasses differing communities and habitats. • Sizes, shapes, and interconnectedness of patches within habitats, communities, or ecosystems

15. Some groups contain more species than others • Species are not evenly distributed among taxonomic groups. • Insects predominate over all other life-forms. • 40% of all insects are beetles. • Groups accumulate species by: • Adaptive radiation • Allopatric speciation • Low rates of extinction

16. Measuring biodiversity is not easy • Species richness is a good gauge for overall biodiversity. • Estimates of 5–30 million species on Earth; only 1.7–2 million species have been identified and described. • Very difficult to identify species • Small organisms are easily overlooked. • Many species look identical until closely examined. • Many remote spots on Earth remain unexplored.

17. Biodiversity is unevenly distributed • Living things are distributed unevenly across Earth. • Latitudinal gradient: species richness increases toward the equator • Equatorial regions have higher plant productivity, stable climates, and no glaciation. • Diverse habitats increase niches, which increase species diversity. • Ecotones (areas where habitats intermix) often have higher diversity.

18. Biodiversity losses and species extinction • Extinction: occurs when the last member of a species dies and the species ceases to exist • Extirpation: the disappearance of a particular population from a given area, but not the entire species globally • Can lead to extinction • Paleontologists estimate 99% of all species are now extinct. • Background rate of extinction: natural extinctions for a variety of reasons • Mammal and marine species: 1 species out of 1,000 become extinct every 1,000 to 10,000 years, which translates to: • 1 extinction per 1–10 million species

20. The Big Five • Ordovician-Silurian extinction - 439 million years ago, 60% extinct • Late Devonian extinction - 364 million years ago, 70% extinct • Permian-Triassic extinction - 251 million years ago, 90% extinct • End Triassic extinction, - 199 million to 214 million years ago, 44% extinct • Cretaceous-Tertiary extinction, about 65 million years ago, 85% extinct

21. Extinctions • Habitat Disruption • Volcanic Eruptions • Asteroid Impacts • Sea Level Change • Habitat Modification • Climate Change • Mountain-Building • Sea Level Change • Precipitation Change • Toxic Materials • “Exotic” Species Introductions • Continental Drift

22. The current mass extinction is human caused

23. People have hunted species to extinction for millennia Extinctions followed human arrival on islands and continents.

24. Current extinction rates are higher than normal • The Red List: an updated list of species facing high risks of extinctions • 22% of mammal species • 12% of bird species • 16–86% of all other species

25. Biodiversity loss is more than extinction

26. Biodiversity loss has many causes • Reasons for biodiversity losses are multifaceted, complex, and hard to determine. • Four primary causes of population decline are: • Habitat alteration • Invasive species • Pollution • Overharvesting • Global climate change now is the fifth cause. • Each factor is intensified by human population growth and resource consumption.

27. Habitat alteration causes biodiversity loss • The greatest cause of biodiversity loss • Farming • Grazing • Clearing forests • Hydroelectric dams • Urbanization and suburban sprawl • A few species (i.e., pigeons, rats) benefit from changing habitats. Less than 1% of North America’s Great Plains remains, and grassland bird populations have declined 82–99%.

28. Habitat alteration occurs in every biome Particularly in tropical rainforests, tropical dry forests, and savannas

29. Invasive species cause biodiversity loss • Introduction of non-native species to new environments • Accidental: zebra mussels • Intentional: food crops • Island species haven’t evolved defenses and are very vulnerable. • Invaders have no natural predators, competitors, or parasites. • Cost billions of dollars in economic damage each year

30. Invasive Species Gypsy Moth, native in Eurasia, invasive in NE US Indian Mongoose , native in SE Asia, Invasive in Hawaii

31. Pollution causes biodiversity loss • Harms organisms in many ways • Air pollution • Water pollution • Agricultural runoff • Oil and chemical spills • Although pollution is a substantial threat… • It tends to cause less damage than habitat alteration or invasive species.

32. Overharvesting causes biodiversity loss • Vulnerable species are large, few in number, long-lived, and have few young (K-selected species). • The Siberian tiger is hunted without rules and regulations. • The early 1990s saw increased tiger poaching because of powerful economic incentives. • Many other species affected: Atlantic gray whale, sharks, gorillas Today the oceans contain only 10% of the large animals they once did.

33. Climate change causes biodiversity loss

34. Warming has been the greatest in the Arctic The polar bear has been listed on the U.S. endangered species list.

35. Consequences from Biodiversity Loss Degradation of Ecosystem Function Loss of Ecosystem Services Overharvesting Habitat Alteration Pollution Biodiversity Loss Economic Loss Loss of Food Services Human Population Growth Health Impacts Invasive Species Loss of Tourism & Recreation Social Disruption Global Climate Change Loss of Natural Medicine More Severe Weather Loss of Aesthics

36. Biodiversity benefits: free ecosystem services • Provides food, shelter, fuel • Purifies air and water and detoxifies wastes • Stabilizes climate, moderates floods, droughts, wind, temperature • Generates and renews soil fertility and cycles nutrients • Pollinates plants and controls pests and disease • Maintains genetic resources • Provides cultural and aesthetic benefits • Allows us to adapt to change The annual value of just 17 ecosystem services = $16 - 54 trillion per year

38. Biodiversity benefits: maintain ecosystem function • Extinction of a keystone species may cause other species to decline or disappear.

39. Biodiversity benefits: enhanced food security • Genetic diversity in crops is enormously valuable. • Turkey’s wheat crops received $50 billion worth of disease resistance from wild wheat. Capybara; easily ranched near open water habitats

40. Organisms provide drugs and medicines • Each year pharmaceutical products owing their origin to wild species generate up to $150 billion in sales.

41. Biodiversity benefits: economic benefits • Biodiversity provides a source of income through tourism. • Ecotourism: people visit natural areas, creating economic opportunity for residents living near those areas • Costa Rica: rainforests • Australia: Great Barrier Reef • Belize: reefs, caves, and rainforests

42. Biodiversity benefits: people value nature • Biophilia: connections that humans subconsciously seek with life • Our affinity for parks and wildlife • Keeping of pets • High value of real estate with views of natural lands • Nature deficit disorder: alienation from the natural environment • May be behind the emotional and physical problems of the young

43. Do we have ethical obligations to other species? • Can wildlife and humans co-exist? “Last night there were about twenty elephants on my farm,” says Ngathu from Kenya. “We drummed and yelled to chase them away, but they trampled down fences and ruined fields we had recently planted with corn.”

44. Conservation biology responds to biodiversity loss • Conservation biology: studies the factors that influence the loss, protection, and restoration of biodiversity • They try to learn how likely a population is to persist or go extinct, particularly small and isolated ones. • Minimum viable population: how small a population can become before it runs into problems

45. Island biogeography • Protecting habitat and species requires thinking and working at the landscape level. • Equilibrium theory of island biogeography: explains how species come to be distributed among oceanic islands

46. Species richness results from island size and distance • Fewer species colonize an island far from the mainland. • Large islands have higher immigration rates. • Large islands have lower extinction rates.

47. The species-area curve • Area effect: large islands contain more species than small islands • They are easier to find, and their larger populations have lower extinction rates. • They possess more habitats. The number of species on an island doubles as the island size increases tenfold.

48. Small “islands” of habitat rapidly lose species • Forests are fragmented by roads and logging. • Small forest fragments lose diversity fastest. • Starting with large species

49. Should conservation focus on endangered species? • Endangered Species Act (1973) (ESA): forbids the government and private citizens from taking actions that destroy endangered species or their habitats • To prevent extinction • Stabilize declining populations • Enable populations to recover • As of 2008, the U.S. had 1,046 species listed as endangered and 307 listed as “threatened.”

50. Despite opposition, the ESA has had successes • Peregrine falcons, brown pelicans, bald eagles, and others have recovered and are no longer listed as endangered. Should we remove protection once a species recovers?