Presentation on theme: "Chapter 12: Sustaining biodiversity (species/extinction) Land and Water Use Unit."— Presentation transcript:
Chapter 12: Sustaining biodiversity (species/extinction) Land and Water Use Unit
Types of Extinction Local extinction: better known as extirpation. A species is no longer found in an area it used to inhabit, but can be found elsewhere. Ecological extinction: too few members of that species exist in an area to continue to play their role in the ecology of an area (predator, prey, etc.) Biological extinction: true extinction. No members of that species exist on Earth. Example: dinosaurs, passenger pigeon
Remember these? Background extinction: Normal extinction that occurs at a low rate: 1-5 species per million. May be due to evolution… Mass extinction: Extremely high rates of extinction. There have been 5 mass extinctions and we may be in a possible 6 th mass extinction. Reread 6 th extinction from Ch. 1 internet activity for homework.
Whore you calling threatened? Endangered species: Numbers are so low that the species could soon become extinct. Protected by law. (Endangered Species Act of 1973) Threatened species: Numbers are low enough that species could soon become threatened. Protected by law. Special concern: Animals that are suspected to be experiencing problems, but no documentation has been made. Not protected by law.
CharacteristicExamples Low reproductive rate (K-strategist) Specialized niche Narrow distribution Feeds at high trophic level Fixed migratory patterns Rare Commercially valuable Large territories 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 What puts them at risk?
Fish Percentage of threatened/ endangered Mammals Reptiles Plants Birds 34% (51% of freshwater species) 24% 20% 14% 12%
Indian Tiger Range 100 years ago Range today (about 2,300 left) Indian Tiger
Black Rhino Range in 1700 Range today (about 2,400 left) Black Rhino
African Elephant Probable range 1600 Range today (300,000 left) African Elephant
Figure 12-7d Page 232 Asian or Indian Elephant Former range Range today (34,000–54,000 left) Asian Elephant
Maintenance through Conservation Maintaining and protecting wildlife consists of 3 major approaches: 1.Species approach – protecting endangered species though legislation. 2.Ecosystem approach – persevering balanced ecosystems
Maintenance through Conservation 3. Wildlife management approach – managing game species for sustained yield through interaction treaties to protect migration species, improving wild life habitats, regulating hunting and fishing, creating harvest quotas and developing population management plans.
Why should we care??? Instrumental value Gene pool/genetic information (useful for vaccines, resistance) Wildlife tourism (existential value) Recreational pleasure Place in ecosystem (pollinator, keystone, indicator, etc) Its like burning books before you read them.
Causes of endangerment Habitat destruction (for resources, farmland, residential, pollution) Introduction of alien/non-native/invasive species Overexploitation (over-harvested, over- hunted, poaching) Disease Pollution Interrupted migration
Oops – I did it again Introduced on purpose: –Kudzu vine (prevent erosion ) –House sparrow (eat cankerworms -1950) –Carp (worlds finest fish ) –Nutria (fur) –Ring-neck pheasant (hunting -1881)
Unintentional introduction On ships, boats On people On shipping crates On tire treads Examples: –Fire ants –Zebra mussel –Water millfoil
Figure 12-9b Page 235 Sea lamprey (attached to lake trout) Argentina fire antEurasian muffleBrown tree snakeCommon pigeon (Rock dove) Formosan termiteZebra musselAsian long-horned beetle Asian tiger mosquitoGypsy moth larvae Accidentally introduced Species
Argentina Fire Ant Distribution
Characteristics of Successful 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 Characteristics of Ecosystems Vulnerable to Invader Species Similar climate 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 Will we be invaded?
Its the law… CITES: Convention on International Trade in Endangered Species: 1975, treaty signed by 160 countries, lists 900 species that cannot be traded either alive or as products. CBD: Convention on Biological Diversity. Signed by 186 countries legally binds governments of signing countries to attempt to reverse the loss of biological diversity. Each country forms a national conservation plan. Lacey Act of 1900: US act, cant transport live or dead wild animals or parts of them across state borders without permits Endangered Species Act: Amended in 1982, 85, 88. Identifies animals as threatened or endangered and protects them by law.
Zoos or Not? Read pages Utilize the internet for additional support for your essay. Essay – should be 3-4 paragraphs on whether or not zoos/aquariums/captivity programs should be utilized for endangered/threatened species (with no intention of releasing to the wild)