1. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CHAPTER 60 LECTURE SLIDES Prepared by Brenda Leady University of Toledo

2. 2 Biodiversity can be examined at 3 levels  _____________– amount of genetic variation that occurs within and between populations  _____________– threatened species are likely to become endangered, endangered species are in danger of extinction  _____________– diversity of structure and function within an ecosystem Conservation biology protects ______________________at all levels

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4. 4 Why conserve biodiversity? 1. 2. 3.

5. 5 Economic values  Zea diploperenis, an ancient ______ relative, is resistant to many corn viruses and its genes are being used to develop resistant corn  25% of prescription drugs in the US are derived from _______  Desert pupfishes are models for research on human _______ disease World’s ecosystems worth more than $_______ a year

6. 6 How much diversity for proper function?  _____ hypothesis linking diversity and stability suggests a linear correlation between diversity and ecosystem function  ______ hypothesis – species are like rivets with each playing a small critical role

7. 7  __________ hypothesis – most species are redundant, they take up space but do not add to diversity, but keystone species are vital to function  _________ hypothesis – ecosystem function can change as the number of species increases or decreases but the direction of change is not predictable

8. Ecotron Experiments Showed the Relationship Between Biodiversity and Ecosystem Function 14 environmental chambers used to replicate terrestrial communities Differed only in biodiversity Each had 4 trophic levels Analyzed a range of measures of ecosystem function – community respiration, decomposition, nutrient retention rates, and productivity Community productivity, % change in vegetation cover, increased as species richness increased First experimental demonstration that loss of biodiversity can impair ecosystem function

10. 10 Field experiments  Plots sown with up to 24 species of native prairie plants  Results showed again that more diverse plots had increased productivity and used nutrients more efficiently than less diverse ones  Frequency of invasive plant species and foliar fungal diseases decreased with increased richness  ___________ species richness increased with plant species richness

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12. 12 Causes of extinction and loss of biodiversity Extinction is a natural process  Average life span of a species in the fossil record is around 4 million years Background extinction is 1 species every ______ years May be higher at 1 or 2 every 100 years Biodiversity crisis – in the past 100 years 20 species of ____________ and over 40 species of __________ have gone extinct Growth of __________ population linked to number of extinctions

13. 13 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 0 2 3 4 5 6 10 0 20 30 40 50 60 Number of extinct species Year 1600–17001700–18001800–19001900–2000 Number of humans (billions) Birds Mammals

14. 14 Main causes of extinction  Species moved by humans from a native location to another location Invasive species – out compete native species for space and resources 3 categories of interaction  Competition – not shown to cause extinction  Predation – rats, cats and mongoose account for 43% of recorded bird extinctions  Disease – 50% of native Hawaiian birds extinct due to avian malaria

15. 15  Passenger pigeon and Carolina parakeet hunted to extinction by the early 20 th century Whale species driven to the brink of extinction prior to a 1988 moratorium on commercial whaling  Deforestation a prime cause of extinction Ivory-billed woodpecker assumed extinct due to logging (unconfirmed sighting in 2004) Planting agricultural crops and urbanization also destroy habitat

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17.  Human-induced climate change, or global warming, has been implicated in the dramatic decrease in the population sizes of frog species in Central and South America  Unless greenhouse gas emissions are cut drastically, climate change will cause 15–37% of the species 6 biodiversity-rich regions to go extinct by the year 2050 17

18. 18  Inbreeding – mating among relatives More likely when population small Survivorship of offspring can decline Greater prairie chicken – reduced to population with 5 or 6 males, resulted in steady reduction of hatching success, brought in Kansas birds to increase diversity Extinction vortex

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20. 20  Genetic drift Random change in allele frequency attributable to chance Allee effect – some individuals fail to mate by chance Small isolated populations more prone Lose a percentage of original diversity at 1/(2N) per generation, N=population size Can be countered with immigration

21. 21  Number of individuals that contribute genes to future populations May be _________ than number of individuals in ____________ ________ mating structure – a few males command all the breedings  In a population of 250 males and 250 females  N e is 100% of all individuals breed  N e is 8% if 10 males breed with 250 females

22. 22 Grizzly bears need large population sizes Effective population size is 25% (not all bears breed) Even fairly large, isolated populations are vulnerable to the harmful effects of loss of genetic variation Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Distribution in 1850 Current distribution Selkirks Bitterroot Yellowstone Oregon Idaho Wyoming Montana Washington North Cascades Cabinet Yaak Northern Continental Divide

23. 23 Conservation strategies Habitat conservation focuses on  _____________________– greatest number of species Just 17 countries are home to nearly 70% of all known species top the list Do not necessarily contain the most unique species – 208 mammal species are shared between Peru and Ecuador (part of the 17)

24. 24  Areas rich in endemic species _______________ are found only in a particular place and nowhere else _____________ have the widest variety of endemic species with at least 1500 species of vascular plants and lost 70% of original habitat 34 hot spots occupy only 2.3% of Earth’s surface but contain 150,000 endemic plant species (50% of world total) __________________ are rich in endemics and may receive more attention/funding at the expense of other areas

25. 25 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mesoamerica Caribbean Madagascar Sundaland Wallacea New Zealand Melanesian Islands Philippines Japan Caucasus 30º 45º 60º 75º 15º 0º0º Latitude Himalaya Mountains of Central Asia Mountains of Central Asia Mediterranean Basin Mediterranean Basin Irano- Anatolian Irano- Anatolian Horn of Africa Horn of Africa Eastern Afromontane Eastern Afromontane Brazil’s Cerrado Tropical Andes Tropical Andes Choco/ Darien/ Western Ecuador Madrean pine-oak woodlands Madrean pine-oak woodlands California Floristic Province West African forests Succulent Karoo Brazil’s Atlantic Forest Central Chile Coastal forests of Eastern Africa Southwest Australia New Caledonia Indo- Burma Indo- Burma South Central China South Central China Western Ghats and Sri Lanka Polynesia/ Micronesia Cape Floristic Province

26. 26  While the Pampas of South America does not compare well to the richness or endemics of the rain forest, it is a unique area that without preservation could disappear Many areas that are threatened but not biologically rich may be preserved in addition to the less immediately threatened, but richer, tropical forests

27. 27 Theory and practice of reserve design  Principles of island biogeography Wildlife reserves and sanctuaries are __________ The _______ the area, the _________ number of species would be protected SLOSS debate – single large reserve may be able to preserve a larger population or several smaller ones may contain a broader variety of habitats and a reduced risk to fire or disease

28. 28 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Better (a) Large or small(c) Close or far(d) Clustered or linear(e) Linked or separate(f) Round or oblong (b) Single large or several small Worse

29. 29  Principles of landscape ecology Examines the spatial arrangement of elements in communities and ecosystems Link small reserves with ___________ or _________________ Hedgerows in Europe function as corridors between forest fragments In China, corridors of habitat link small, adjacent population of giant pandas Parks are often designed to minimize edge effects so circular parks are preferred over long, skinny parks

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31. 31 Economic considerations  Principles of island biogeography and landscape ecology useful  Economic considerations often enter in the choice of areas to preserve  In Africa, several large parks contain sizable populations In the 1980s, populations of black rhino and elephant declined due to poaching Rates of decline in elephants and rhinos were more linked to conservation efforts and spending than to land area

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33. Single-species approach  ___________________________– species whose status confirms the overall health of an ecosystem Corals are good indicators of … Proliferation of the dark variety of the peppered moth (Bistonbetularia) has been shown to be a good indicator of air pollution Polar bears are an indicator for … 33

34. Single-species approach  ___________________– habitat requirements are so large that protecting them also protects many other species in the same habitats A Northern spotted owl pair needs 800 hectares of old-growth forest for survival and reproduction To protect Zea diploperennis, the land where it grows was bought and a nature reserve established  _______________________– single large or instantly recognizable species Attractive and engender public support American buffalo, giant panda, Florida panther 34

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36. 36 ___________________ – species within a community that have a role out of proportion with their abundance  Beaver can completely alter a community by building a dam and flooding an entire river valley  Palm nuts and figs produce fruit during otherwise fruitless times and are critical resources  Not a dominant species – one that has a large effect in a community because of its abundance or high biomass  Gopher tortoises and beavers are also ecosystem engineers – create, modify and maintain habitats

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38. 38  Full or partial repair or replacement of biological habitats and/or their populations that have been damaged  Can restore or rehabilitate a habitat  Can return species to the wild following captive breeding  Bioremediation – use of living organisms to detoxify polluted habitats

39. 39 Habitat restoration  3 basic approaches ____________________ – attempt to put back exactly what was there prior to disturbance ___________________ – return habitat to something similar but less than full restoration ___________________– replaces original ecosystem with a different one – deciduous forest replaced after mining by grassland

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41.  use of living organisms, usually microbes or plants, to detoxify polluted habitats such as dump sites or oil spills  Some bacteria can detoxify contaminants  Certain plants can accumulate toxins in their tissues and are then harvested, removing the poison from the system 41

42. 42  Propagation of animals and plants outside their natural habitat to produce stock for subsequent release into the wild  Mid-1960s peregrine falcon became extinct in eastern US due to DDT effects In 1999 removed from Endangered Species List  California condors were down to 22 birds 2002 milestone – pair of captive-reared birds bred in wild

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44. Can Cloning Save Endangered Species? 1997, Dolly the cloned sheep announced Cow gave birth to a cloned Asian gaur from a single skin cell from a dead gaur Javan banteng successfully cloned in 2003 In 2005, clones of African wildcat successfully bred Unresolved issues  Reproductive knowledge needed is immense  Identify surrogate mothers of other species  Cloning does not address the root cause of loss – habitat fragmentation or poaching  May or may not be able to reintroduce genetic variability lost with deceased animals