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Chapter 11

Chapter 11. Sustaining Biodiversity: The Species Approach. Species Extinction. Local extinction : Ecological extinction : Biological extinction : Endangered Species: Threatened Species : 30,000 plants and animals are endangered or threatened. Species Extinction .

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Chapter 11

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  1. Chapter 11 Sustaining Biodiversity: The Species Approach

  2. Species Extinction • Local extinction: • Ecological extinction: • Biological extinction: • Endangered Species: • Threatened Species: • 30,000 plants and animals are endangered or threatened.

  3. Species Extinction • Estimating extinction rate is hard to do. • Extinction can take a long time • We only know of 1.4 million species when there could be 4-100 million. • We have little knowledge on most species. • Compare current extinction to fossil records of past extinctions. • Observe how the # of species present increases with size of an area • Species-area ratio suggest that on average a 90% habitat loss causes the extinction of about 50% of species.

  4. Characteristic Examples Blue whale, giant panda, rhinoceros Blue whale, giant panda, Everglades kite Many island species, elephant seal, desert pupfish Bengal tiger, bald eagle, grizzly bear Blue whale, whooping crane, sea turtles Many island species, African violet, some orchids Snow leopard, tiger, elephant, rhinoceros, rare plants and birds California condor, grizzly bear, Florida panther Low reproductive rate (K-strategist) Specialized niche Narrow distribution Feeds at high trophic level Fixed migratory patterns Rare Commercially valuable Large territories Fig. 11-4, p. 225

  5. Species Extinction • Effects of human activities on extinction rates. • Extinction rate was 0.0001% before humans • 0.01% to 1% now • 1% extinction rate would mean at least 1/5 of plants and animals will be extinct by 2030 or ½ by 2050.

  6. Importance of Wild Species • Instrumental value • Food crops, fuel wood, lumber, paper, medicines • 62% of all cancer drugs were created by bioprospecting discoveries. • Genetic information • Allows species to change with changing environments • Humans use this info for new crops and foods • Wild species provide us with ways to learn how nature works and sustains itself • Recreational pleasure • Ecotourism- $500 billion/yr (1 male lion living to 7 will generate 515,000 in tourists dollars in Kenya but only $1,000 if killed for skin)

  7. H.I.P.P.O Habitat loss, degradation and fragmentation • HIPPO: • Greatest threat is habitat loss, degradation and fragmentation • Deforestation of the TRF is leading cause • Hotspots are very vulnerable • Most national parks and nature reserves are surrounded by damaging logging, mining and industrial activities. • Habitat fragmentation: • Block migration routes and cause species population to decrease in smaller areas • More vulnerable to predators, competition, disease and catastrophic events • Increase road kill

  8. H.I.P.P.OInvasive species • 2nd biggest cause of extinctions • Most species introduced to new areas are beneficial • Crops, cattle, poultry • 1 in 7 nonnative species are harmful • No natural predators, competitors, parasites, or pathogens to control population • Cost U.S. $137 billion/year ($16 million/hr)

  9. H.I.P.P.OInvasive species • Accidently introduced invasive species • Stowaways in aircrafts, ballast water from tankers, hitchhikers on imported products • Comb jellies in black sea have wiped out some native fish populations b/c the feed on the planktonic larvae • Zebra mussels in Great Lakes have blocked water pipe systems • Fire ants were introduced in Mobile, Al and have caused $600 million/yr damage to crops and power poles.

  10. H.I.P.P.OInvasive species • Solutions • Prevent them from being introduced • Research to identify major characteristics that allow species to become successful invaders • Increase ground surveys and satellite observations to detect and monitor species invasions to better predict spreading and future invasions. • Improve inspections of imported goods • Identify major harmful invasive species and pass law banning their transfer from country to country • Require cargo ships to discharge their ballast water or other methods to ride possible invasive species • Increase research to find and introduce natural predators, parasites, and disease causing bacteria and viruses to control populations.

  11. What Can You Do? Invasive Species • Do not allow wild animals to escape. • Do not spread wild plants to other areas. • Do not dump the contents of an aquarium into waterways, wetlands, or storm drains. • When camping use wood near your campsite instead of bringing firewood from somewhere else. • Do not dump unused bait into the water. • After dogs visit woods or the water brush them before taking them home. • After each use clean your vehicle, mountain bike, surfboard, kayaks, canoes, boats, tent, hiking boots, and other gear before heading for home. • Empty all water from canoes, kayaks, dive gear, and other outdoor equipment before heading home. • Plant a variety of trees, shrubs, and other plants in your yard to reduce losses from invasive species. • Do not buy plants from overseas or swap them with others using the Internet. Fig. 11-14, p. 236

  12. Characteristics of Successful Invader Species Characteristics of Ecosystems Vulnerable to Invader Species • High reproductive rate, short generation time (r-selected species) • Pioneer species • Long lived • High dispersal rate • Release growth-inhibiting chemicals into soil • Generalists • High genetic variability • Climate similar to habitat of invader • Absence of predators on invading species • Early successional systems • Low diversity of native species • Absence of fire • Disturbed by human activities Fig. 11-13, p. 236

  13. H.I.P.P.OPopulation growth, Pollution and Climate change • Population growth and excessive waste have caused many premature extinctions • Pesticides- kill 1/5 of U.S. beneficial honeybee colonies, 67 million birds and 6-14 million fish each year. • Climate change • Could drive more than ¼ of all land animals and plants to extinction by the end of the century.

  14. H.I.P.P.OOverexploitation • Legitimate trade of wildlife is worth $10 billion/yr. • Illegal trade is worth $6-10 billion/yr • Some species (dead or alive) are worth 100s of 1000s of dollars • Killing species we don’t like • Some species are killed because they are considered pests (wolfs eating cattle or elephants trampling crops) • Exotic pets and plants

  15. Protecting Wild Species: Legal and Economic Approaches • 1975 Convention on International Trade in Endangered Species (CITES) • 169 countries signed • 900 species that can not be traded • 5000 animals and 28,000 plants trade is restricted • Convention on Biological Diversity (CBD) • 188 countries signed • Reverse the global decline of biological diversity

  16. Protecting Wild Species: Legal and Economic Approaches • U.S. Endangered Species Act 1973 • Identify and legally protect endangered species in the U.S. • National Marine Fisheries Services (NMFS) • U.S. Fish and Wildlife Services (USFWS) • Decisions must be based on biological facts only • Between 1973-2006 the # on the ES list went from 92 to 1260 • Once a species is on ES list a plan is put in to place to help recovery.

  17. Protecting Wild Species: Legal and Economic Approaches • Encouraging private landowners to protect endangered species • Habitat conservation plans • Part of critical habitat is allowed to be destroyed in exchange for taking steps to protect species (setting aside part of habitat, pay to relocate species, pay government to purchase suitable habitat elsewhere) • Safe harbor agreements: • Voluntary candidate conservation agreements:

  18. Protecting Wild Species: The Sanctuary Approach • Since 1903 there are 544 refuges • More then ¾ of refuges serve as vital wetlands for migratory birds • More then 1/5 of endangered and threatened species have habitats in refuges • Harmful activities occur in about 60% of refuges • Invasive species are a huge threat • Too much fishing and hunting and use of boats and off road vehicles cause damage

  19. Protecting Wild Species: The Sanctuary Approach • National Refuge System Improvement Act (1997) • insuring that the biological diversity and integrity and environmental health of the system are maintained. • Gene banks, botanical gardens, and wildlife farms • Gene banks: • Cons: some seeds can’t be kept in a bank, expensive, accidental destruction could destroy seeds • Botanical gardens: • Cons: too little storage capacity and funding to preserve rare and threatened species • Wildlife farms: • Zoos and Aquariums • Long term goal to reintroduce endangered and threatened species into the wild • Most don’t have money to successfully help threatened or endangered species but are still beneficial because of educational opportunities.

  20. Reconciliation Ecology • Find ways to share the places we dominate with other species • Examples: • For pollinators: Have communities agree not to spray pesticides, plant gardens of flowering plants, build nesting areas • Use native vegetation- reduce the need for water, and mowing (pollution) • Roof top gardens

  21. What Can You Do? Protecting Species • Do not buy furs, ivory products, and other materials made from endangered or threatened animal species. • Do not buy wood and paper products produced by cutting remaining old-growth forests in the tropics. • Do not buy birds, snakes, turtles, tropical fish, and other animals that are taken from the wild. • Do not buy orchids, cacti, and other plants that are taken from the wild. • Spread the word. Talk to your friends and relatives about this problem and what they can do about it. Fig. 11-21, p. 246

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