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Chapter 18 Conservation of Biodiversity. Extinction is Forever Extinction (aka biological extinction) – A process in which an entire species ceases to.

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Presentation on theme: "Chapter 18 Conservation of Biodiversity. Extinction is Forever Extinction (aka biological extinction) – A process in which an entire species ceases to."— Presentation transcript:

1 Chapter 18 Conservation of Biodiversity

2 Extinction is Forever Extinction (aka biological extinction) – A process in which an entire species ceases to exist – Local extinction is when a population of a species becomes extinct over a large region, but not globally Fig. 4-11, p. 92 This male golden toad lived in Costa Rica’s high-altitude Monteverde Cloud Forest Reserve. The species became extinct in 1989 apparently because its habitat dried up.

3 Background extinction – Low rate of species extinction that has occurred throughout earth’s history – ~1-5 species/million annually Mass extinction – Significant rate above background level – Catastrophic, widespread, often global – Wipes out 25-95% of species – Occurred 3-5x in the last 500 my The 6 th Mass Extinction

4 Extinction Rates Are Rising Rapidly Current extinction rate is at least 100 times higher than typical background rate of.0001% Will rise to 10,000 times the background rate by the end of the century – Rate will rise to 1% per year – ¼ to ½ of the world’s plant and animal species Conservative estimates of extinction = 0.01-1.0% – Growth of human population will increase this loss

5 – Rates are higher where there are more endangered species – Tropical forests and coral reefs, wetlands and estuaries— sites of new species—being destroyed Extinction Rates Are Rising Rapidly

6 Speciation crisis – Increasing rate of extinction – Limiting long-term recovery of biodiversity by reducing the rate of speciation » Destroying potential colonization sites for the emergence of new species Extinction Rates Are Rising Rapidly

7 Species Are a Vital Part of the Earth’s Natural Capital 4 reasons to prevent extinctions 1.Species provide natural resources and natural services – Insects for pollination – Birds for pest control

8 Species Are a Vital Part of the Earth’s Natural Capital 4 reasons to prevent extinctions 2.Most species contribute economic services – Plants for food, fuel, lumber, medicine – Ecotourism

9 Species Are a Vital Part of the Earth’s Natural Capital 3.It will take 5-10 million years to regain species biodiversity

10 Species Are a Vital Part of the Earth’s Natural Capital 4. Many people believe species have an intrinsic right to exist

11 Genetic Diversity Scientists want to conserve genetic diversity so that the species can survive environmental change and inbreeding will not occur. Inbreeding occurs when individuals with similar genotypes, generally relatives, breed with each other.

12 Genetic Diversity

13 Categories of Endangerment Endangered species – So few members that the species could soon become extinct Threatened species (vulnerable species) – Still enough members to survive, but numbers declining -- may soon be endangered Fig. 9-2, p. 193

14 Categories of Endangerment

15 Fig. 9-3, p. 194 Characteristics of Species That Are Prone to Ecological and Biological Extinction

16 Fig. 9-3, p. 194 Characteristics of Species That Are Prone to Ecological and Biological Extinction

17 Loss of Habitat Is the Single Greatest Threat to Species: Remember HIPCO Habitat destruction, degradation, and fragmentation Invasive (nonnative) species Pollution Climate change Overexploitation

18 Habitat Loss For most species the greatest cause of decline and extinction is habitat loss. Most habitat loss is due to human development

19 Some Human Activities Are Causing Extinctions Human activity has disturbed at least half of the earth’s land surface – Fills in wetlands – Converts grasslands and forests to crop fields and urban areas – Pollution of land and water Fig. 9-2, p. 193

20 Habitat Fragmentation Habitat fragmentation – Large intact habitat divided by roads, crops, urban development – Leaves habitat islands – Blocks migration routes – Divides populations – Inhibits migrations and colonization – Inhibits finding food National parks and nature reserves as habitat islands

21 Fig. 9-10, p. 199 Natural Capital Degradation: Reduction in the Ranges of Four Wildlife Species

22 Historic and Current Florida Panther Rangers

23 Some Deliberately Introduced Species Can Disrupt Ecosystems Nonnative species may have no natural – Predators – Competitors – Parasites – Pathogens

24 Case Study: Why Should We Care about the American Alligator? Largest reptile in North America 1930s: Hunters and poachers Importance of gator holes and nesting mounds: a keystone species 1967: endangered species 1977: comeback, threatened species

25 Fig. 9-11, p. 200 Some Harmful Nonnative Species in the United States

26 Fig. 9-11, p. 200 Some Harmful Nonnative Species in the United States

27 Case Study: The Kudzu Vine Imported from Japan in the 1930s “ The vine that ate the South” Could there be benefits of kudzu? – Fiber for making paper – Kudzu powder reduces desire for alcohol

28 Fig. 9-14, p. 203 What Can You Do? Controlling Invasive Species

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30 Other Causes of Species Extinction: Pollution Pesticides – DDT: Banned in the U.S. in 1972 Bioaccumulation Biomagnification Fig. 9-15, p. 203

31 Other Causes of Species Extinction: Climate Change Fig. 9-1, p. 190

32 Case Study: The Passenger Pigeon: Gone Forever Once one of the world’s most abundant birds Audubon: flock took 3 days to fly over Passenger pigeon hunted to extinction by 1900 – Habitat loss – Commercial hunting – Easy to kill: flew in large flocks and nested in dense colonies Fig. 9-5, p. 194

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34 Illegal Killing, Capturing, and Selling of Wild Species Threatens Biodiversity Poaching and smuggling of animals and plants – Animal parts – Pets – Plants for landscaping and enjoyment Fig. 9-17, p. 205

35 Rising Demand for Bush Meat Threatens Some African Species Indigenous people sustained by bush meat More hunters leading to local extinction of some wild animals West and Central Africa Helps spread HIV/AIDS and Ebola from animals to humans Fig. 9-18, p. 207

36 International Treaties and National Laws Help to Protect Species 1975: Convention on International Trade in Endangered Species (CITES) – Signed by 172 countries The IUCN keeps a list of threatened species, known as the Red List. Each country has its own way to monitor and regulate the import and export of animals on the list.

37 Convention on Biological Diversity In 1992, nations came together and made a treaty to protect biodiversity. Three objectives of the treaty: 1. conserve biodiversity, 2. sustainably use biodiversity, and 3. equitably share the benefits that emerge from the commercial use of genetic resources such as pharmaceutical drugs.

38 Fig. 9-20, p. 210 Confiscated Products Made from Endangered Species

39 Conservation Legislation: Lacey Act One of the earliest laws in the U.S. to control the trade of wildlife. First passed in 1900, the act prohibited the transport of illegally harvested game animals, primarily birds and mammals, across state lines.

40 Conservation Legislation Marine Mammal Protection Act- prohibits the killing of all marine mammals in the U.S. and prohibits the import or export of any marine mammal body parts.

41 Endangered Species Act Endangered Species Act (ESA): 1973 and later amended in 1982, 1985, and 1988 Identify and protect endangered species in the U.S. and abroad National Marine Fisheries Service for ocean species U.S. Fish and Wildlife Service for all others

42 Endangered Species Act Forbids federal agencies (except Defense) from funding or authorizing projects that jeopardize endangered or threatened species USFWS and NMFS prepare recovery plans & purchase critical habitat 2010: 1,370 species officially listed Incentives for private property owners

43 Science Focus: Accomplishments of the Endangered Species Act Four reasons ESA not a failure for removing only 46 species from endangered list 1.Species listed only when in serious danger 2.Takes decades to help endangered species 3.Conditions for more than half of listed species are stable or improving 4.2010: spend only 9 cents per American

44 Zoos and Aquariums Can Protect Some Species Techniques for preserving endangered terrestrial species – Egg pulling – Captive breeding – Artificial insemination – Embryo transfer – Use of incubators – Cross-fostering

45 Zoos and Aquariums Can Protect Some Species Goal of ultimately releasing/reintroducing populations to the wild Limited space and funds

46 Case Study: Trying to Save the California Condor Largest North American bird Nearly extinct (22) – Birds captured and bred in captivity By 2009, 180 in the wild (348 total) – Threatened by lead poisoning

47 Fig. 9-22, p. 213 What Can You Do? Protecting Species

48 We Can Establish Wildlife Refuges and Other Protected Areas 1903: Pelican Island National Wildlife Refuge Wildlife refuges – Most are wetland sanctuaries – More needed for endangered plants Fig. 9-21a, p. 211

49 Size, Shape and Connectedness When designing and managing protected areas we must consider how close to another area they should be, how large the area is, and the amount of edge habitat the area contains. Edge habitat- the area where two different communities come together, typically forming an abrupt transition. Ex. A grassy field meeting a forest.

50 Biosphere Reserves Protected areas consisting of zones that vary in the amount of permissible human impact.


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