AP EXAM

1. AP EXAM More and more and more Review Part 3 Understanding and managing living systems

2. Biodiversity • Is the variation of organisms in a given area • Includes: • Species diversity • Number of different species in an area • Includes species richness (# of species in an area) • And Species evenness (relative distribution of the different species in an area) • Genetic diversity • The genetic variety within a species • Ecosystem diversity • Which is the complexity of species interactions in biological communities

3. Species • Is a group of similar looking organisms that can interbreed and produce fertile offspring • Or defining species based on genetic studies and evolutionary branches • Molecular biology allows scientist to analyze DNA to test relationships between organisms • Is the Red Wolf endangered from low numbers or b/c it’s a hybrid from a gray wolf and a coyote • Mitochondrial DNA indicates that it is a hybrid, but from how long ago? • USFWS has listed it as endangered

4. Biodiversity Hot Spots • Concentrated around tropical regions • Are areas that have 1,500 endemic (native) species and have lost 70 percent of their habitat due to habitat disruption and invasion of exotic species • 34 hot spots have 1.4% of the world’s area but 75% of the world’s threatened mammals, birds, and amphibians • Tend to be islands: Madagascar, Indonesia, Philippines • Geographic isolation results in highly unique flora and fauna

5. Benefits of Biodiversity • Utilitarian benefits: primitive societies used wild plants and animals to provide clothing, food and shelter. Nearly all is now cultivated • Ecological benefits: • plants function in carbon cycle • animals help pollinate • soil formation, pest control, waste disposal and water purification are all dependent upon the species that make up the earth • Nature has aesthetic value

6. Extinction • Is the elimination of an entire species when the last of its members have died • It is irreversible process • It is perfectly natural process, as species become less suited over time to changes in the environment • Species arise through mutation and natural selection, so those not as “fit” become extinct through the same processes • Background extinction rate is the natural reae of extinction • Mass extinctions have occurred periodically, followed by radiation and rapid evolution of species • Humans are currently accelerating extinctions by damaging habitats • Current extinction rates are from 100-1,000 times background extinction levels • Primary threats to biodiversity are habitat disruption, invasive species, pollution, population, and overharvesting

7. Habitat Disruption • TWO main reasons • Agriculture • for crops or livestock • Timber cutting • Provides firewood, charcoal, lumber, and pulp • Also disruption for construction and commercial development • Humans drain wetlands and flood other areas with water diversion projects • Mining disrupts significant amounts of habitat

8. Exotic Species • Considered biotic pollution • An introduction of a non-native species into an area where it is not natural • May be accidental (Zebra mussels via ballast water) • Or deliberate introduced (melaleuca and Australian pine in South Florida to protect canals, levees, and other areas from erosion) • Considered invasive due to lack of controls on population growth in the new area • Tropical areas with high tourism and ports are most susceptible • Islands are extremely vulnerable b/c of uniqueness

9. Solutions to Exotic Species • All solutions can be expensive and time consuming • Mechanical control: invasive is physically removed • Biological control: where you introduce a predator or parasite is introduced to control the pest • Ecological control: fire kills exotics and allows fire resistant natives to regenerate

10. Pollution • Humans pollute air, water, and soil on a regular basis • Pesticides, PCBs, dioxins, mercury and lead • Water pollutants include sediment, organic waste and nitrates and phosphates • Regional problem of acid deposition and global warming are having adverse effects on a wide variety of ecosystems throughout the world

11. Human Population • The ever-increasing human population affects biodiverstiy as humans are forced to move into previously uninhabited areas. • To support the huge population, we must harvest more timber, raise more grain and lievestock, harvest more fish, and mine for more nonrenewable resources than ever before in the history of humans

12. Overharvesting • Has lead to the endangerment and extinction of numerous species in the world • American passenger pigeon became extinct in 1914 b/c they were commercially hunted and their food supply swindled as they lost habitat due to deforestation • American bison were killed in the American west in a genocide attempt to destroy Native American populations dependent upon the bison for their livelihood • Shark, bluefin tuna, and marlin are under severe pressure from overfishing • Animals harvested in the wild for the pet trade, zoos, research labs and aquaria

13. Endangered and Threatened Species • Endangered Species Act • Defines endangered species as being in imminent danger of extinction throughout all or most of its range • California condor, whooping crane, giant panda and black rhinoceros • Threatened species is one that is likely to become endangered in the near future, throughout all or a significant portion of its range • Bald eagle, grizzly bear and the American Alligator

14. Characteristics of Endangered Species • Occupy a narrow habitat or occupy a small range • Therefore, altering their habitat has greater risk • Narrow habitat reiterates that species that are native to certain islands are more likely to be threatened • Animals that require a large territory, such as predators, are likely to become extinct if their territory is modified by humans • Animals with low reproductive success, low reproductive rates, or small numbers of offspring per gestation are at risk • Animals that have highly specialize feeding habitats • Animals wit large size b/c they require more space to supply food needs • Grizzly bears need large area to maintain Minimum Viable Population (MVPs)

15. LEGISLATION • By end of 1800s, states had hunting and fishing laws • 1900 Lacey Act: required a federal permit to transport live, dead, or parts of wild animals across state lines • 1973 Endangered Species Act • Disproportionate amount of money spent on “charismatic” creatures • Funding based on emotion not biological impact • Ignore role of keystone and indicator species • Flagship species get attention (manatee and panda) • Opponents argue that economic impacts are not considered before listing

16. More Legislation • 1996 Sustainable Fisheries Act • Amended the Magnuson Fishery Conservation and Management Act of 1976 • Federal government to manage fisheries from 3 to 200 miles off US coast. • Can impose limits on fish taken in this area • Revisions have NMFS implement management and conservation plans • Now manage Atlantic sharks, swordfish, bill fish and bluefin tuna

17. More Legislation • 1975 CITES: Convention on international Trade in Endangered Species of Wild Flora and Fauna • Goal to ensure trade of species does not lead to their extinction • Bans hunting, capturing and selling of endangered or threatened species • Appendix 1: trade prohibited on endangered species • Appendix 2: limited trade on threatened species • Appendix 3: assists in species protected in one country

18. Species Survival Plans • Ex situ conservation: Animals are taken from nature into captivity in zoos and bred in the attempt to increase numbers • Determine what brought species to brink of extinction before reintroducing to wild • Successful breeding programs for black-footed ferret and whooping crane • Captive breeding techniques used to increase genetic diversity • Artificial insemination: transfer of sperm w/o intercourse • Cross incubation: bird of one species hatches another’s egg • Embryo transfer: production of numerous amounts of eggs in a viable female with the use of hormones; eggs are harvested and fertilized in vitro; embryos are transplanted to less desirable genetic stock • Artificial incubation: harvests eggs in nature and rearing the offspring to a viable size in captivity to return to nature • Botanical Gardens serve the same purpose for assisting with the recovery of plant species • Important to set aside habitat for critically endangered species in the wild to maintain as much genetic diversity as possible • Protection from poaching is essential

19. World Land Use • Forest and Woodland 29% • Range and Pasture 27% • Cropland 11% • Other 11% • Cities, arid land that will not support agriculture or grazing, and wetlands

20. Forests • Closed canopy forests are those that have tree crowns that cover 20 % or more of the ground • Open canopy cover less than 20% • Old growth forests had little human intervention • Trees can live entire lifespan • Coast redwoods can live thousands of years and reach 300 ft tall • Temperate deciduous forest or southern pine can live 300-400 years • Largest remaining old growth is boreal in Russia, Canada and tropical forests in Brazil and Oceania

21. Utilitarian Forest Use • Used for lumber, wood pulp • In U.S. mainly from trees managed for sustainable yield • Developing countries harvest for fuelwood and to make charcoal ~50% worldwide • Developing countries sell exotic tropical hardwoods (mahogany and teak) • Harvested from virgin old growth at an unsustainable rate • Forests are damaged due to mining • Clear cut for rangeland