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Transcript
Chapter 10 Biodiversity 10.1 What Is Biodiversity? 10.2 Biodiversity at Risk 10.3 The Future of Biodiversity 10.1 Do now What do you see? Compare the known amounts of species types. - Describe the diversity of species types on Earth, relating the difference between known numbers and estimated numbers. - List and describe three levels of biodiversity. - Explain four ways in which biodiversity is important to ecosystems and humans. - Analyze the potential value of a single species. 10.1 A. A World Rich in Biodiversity • Biodiversity: “biological diversity” means the number of different species in a given area • Unknown Diversity – We know about 1.7 million species, mostly insects – We think there are 10 million more • Known vs. Unknown – Known: collected and described scientifically. – Unknown: exist in the deep ocean, the rainforest etc.. 10.1 A. A World Rich in Biodiversity • Levels of diversity- 3 levels 1. Species diversity: the number of different species in the same area. Carnivores Herbivores Plants Decomposers High diversity Med. diversity Low diversity 10.1 A. A World Rich in Biodiversity • Levels of diversity – 3 levels 2. Ecosystem diversity – the variety of habitats, communities and ecological process in an ecosystem Rainforest Tundra 10.1 A. A World Rich in Biodiversity • Levels of diversity – 3 levels 3. Genetic diversity – the different genes contained within all members of a population – A gene is a piece of DNA that codes for a trait 10.1 B. Species are connected to Ecosystems • Biodiversity affects the stability of a population. • Each species is important – dependent on or depended upon by at least one other species. • When one species disappears from an ecosystem, a strand in a food web is removed. 10.1 B. Species are connected to Ecosystems • Keystone species: • critical to the functioning of the ecosystem in which it lives. • it affects the survival of many other species in its community. EX sea otter. The loss of the sea otter populations led to an unchecked sea urchin population, which ate all the kelp leading to the loss of kelp beds along the U.S. Pacific Coast. 10.1 C. Species and Population Survival • The level of genetic diversity within populations is a critical factor in species survival. • Genetic Variation increases the chances that some members of the population may survive environmental pressures or changes, It allows them to adapt to new situations. • Small and isolated populations are less likely to survive if something changes. Classwork 10.1 C. Species and Population Survival • Bottleneck: when a population becomes very small, so that only a few genetic types survive. • Fewer types means they will be less likely to survive if something changes • Even if the population increases again its genetic diversity will be reduced, thus more likely to inherit genetic diseases. • Example: what if I am a new predator in this “population” and I can’t eat the purple circles, but I easily eat all the other types? What will happen to the population? 10.1 D. Medical and Industrial Uses • ¼ of the drugs in the US come from plants • ~100% of antibiotics come from fungi • Chemicals and industrial materials often developed from chemicals found in all kinds of species 10.1 E. Agricultural Uses • Most crop food around the world comes from areas with high biodiversity. • Depending on few food sources is dangerous. A plant disease can wipe out whole food sources. • Have you heard of the Irish potato famine? 10.1 Agricultural Uses Irish Potato Famine About two-fifths of the population was solely reliant on this cheap crop for their food. During the famine approximately 1 million people died and a million more emigrated from Ireland, causing the island's population to fall by between 20% and 25%. The cause of the famine was a potato disease commonly known as potato blight which destroyed potato crops throughout Europe during the 1840s. Ethics, Aesthetics, and Recreation 10.1 Review questions 1. What is biodiversity? 2. How many species are known to man currently? 3. What is species diversity? 4. What is ecosystem diversity? 5. What is genetic diversity? 6. What is a keystone species? Chapter 10 10.1 What Is Biodiversity? 10.2 Biodiversity at Risk 10.3 The Future of Biodiversity • - Define and give examples of endangered and threatened species. • - Describe several ways that species are being threatened with extinction globally. • - 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. • - Compare the amount of biodiversity in the United States to that of the rest of the world. • Mass extinction :the extinction of many species in a relatively short period of time . - probably caused by a global change in climate. - 10.2 A. Current Extinctions • Between 1800-2100 ~25% of all species will be extinct, scientists say we are the cause. Ex – Polar bears: global warming is destroying their habitat – Rhino: hunted for their horn • Species that are at risk of extinction are those that migrate, need large or special habitats, and those that are exploited by humans. 10.2 A. Current Extinctions • Endangered species: if not protected. Thus it is under protection by regulations or conservation measures. • Threatened species: has been identified to be likely to become endangered, it has a declining population. 10.2 A. Current Extinctions • We’ve been hunting animals to extinction our whole existence. 10.2 B. Are humans the cause? • Habitat destruction: human populations are increasing, this is destroying habitats because they need more land to build homes and to harvest resources. • Fragmentation: species habitats are being broken up, this makes it hard for some to live because they need big areas • Exotic species: new to an area, not native • Invasive exotic species: the environment has no natural predators, so they take over and use all the resources • Poaching: illegal hunting of a species • Pesticides(kill bugs): destroy native plans; can also kill animals 10.2 C. Areas of critical biodiversity • “endemic species”: is a species that is native to a particular place and only found there. • Tropical rain forests: cover ~7% of the earth, but they have ~1/2 of life. • coral reefs: contain the majority of the ocean’s biodiversity, ~60% of them are threatened by people • Biodiversity hotspots: 25 areas have been labeled as “hotspots” because they are the most threatened areas.Ex: – Coastal areas – Rainforests - Islands 10.2 Review 1. What is an endangered species? 2. What is a threatened species? 3. What is poaching? 4. What is an endemic species? 5. What is a biodiversity hotspot? 6. What is habitat fragmentation? 7. What is a mass extinction? Chapter 10 10.1 What Is Biodiversity? 10.2 Biodiversity at Risk 10.3 The Future of Biodiversity • - List and describe four types of efforts to save individual • species. • - Explain the advantages of protecting entire ecosystems • rather than individual species. • - Describe the main provisions of the Endangered Species • Act. • - Discuss ways in which efforts to protect endangered • species can lead to controversy. • - Describe three examples of worldwide cooperative efforts • to prevent extinctions 10.3 A. Saving species one at a time • Captive breeding programs to restore the population of a species – Wildlife experts breed animals in captivity, then release them into the wild. Ex: California condor • In 1986 nearly extinct, birds were bred in captivity and released, in 2005 there are 121 in the wild • Preserving genetic material to save the essence of a species – “germ plasm” hereditary material (chromosomes and genes) usually contained in the protoplasm of germ cells and may be stored as seeds, sperm, eggs, or pure DNA. 10.3 A. Saving species one at a time • Zoos, aquariums – Often house the few remaining members of a species and keep them safe. – Have complex captive breeding programs • Parks, gardens (Botanical Gardens) – House about 90,000 species of plants. 10.3 B. Preserving habitats and ecosystems • Conservation strategies now focus on protecting entire ecosystems to save most of the species in an ecosystem instead of only the ones that have been identified as endangered. • Conservationists are focusing on hotspots Ex: identify areas of native habitat that can be preserved, restored, and linked into large networks • Most effective way to slow the loss of biodiversity 10.3 C. Legal Protections for species • US laws – Strongest in the world – Endangered species act was passed in 1973, it was designed to protect plant and animal species in danger of extinction. • Reintroduced the gray wolf in the NW USA • In 2005 1,272 species were listed as endangered or threatened. You cannot: –Capture endangered/threatened animals for a zoo –Dig up endangered plants –Build a building over an endangered species home 10.3 C. Legal Protections for species • Recovery and habitat conservation plans – Conservationists must make “species recovery plans” to set forth a way to protect or restore the habitat of that species across large areas of land through trade-offs or cooperative agreements. – This is controversial, it sometimes hurts the income of business and people. 10.3 D. International cooperation • International trade and poaching – CITES (Convention on International Trade in Endangered Species.) first made to decrease ivory trade, it worked! • The biodiversity treaty: more than 100 world leaders met at “earth summit” to preserve biodiversity and ensure the sustainable and fair use of genetic resources in all countries. 10.3 Review – Write Q & A 1.What is a captive breeding program? 2.What is the Endangered Species Act? 3.When was the Endangered Species Act passed? 4.What is a habitat conservation plan? 5.What is CITES? 6.What is the Biodiversity Treaty?