AP Exam

1. AP Exam Part One Principles for Understanding Our Environment

2. Succession • Orderly change of species in an ecosystem over time • Primary succession occurs when an area is newly exposed and has previously not had a biological community. The area lacks soil. • Cooled volcanic lava or a boulder rock slide • Secondary succession is more rapid b/c soil is already there. • Burned field • Climax community

3. Cycles Ammonification The process of breaking down nitrogenous wastes and organic matter found in animal waste and dead plants and animals and converting into ammonia (NH3) for absorption by plants as ammonium ions. Therefore, decomposition rates affect the level of nutrients available to plants. • Carbon cycle • Carbon sink-absorbs carbon (ocean, atm,etc) • Nitrogen cycle • nitrogen fixation, nitrification, assimilation, ammonification, denitrification • Phosphorus Cycle • Sulfur Cycle • Water Cycle Nitrogen fixation The process of converting inorganic, molecular nitrogen in the atmosphere (N2)to ammonia. In nature it is carried out by a few species of bacteria, on which all life depends. Assimilation The process by which plants take in nitrates through their root hairs. Denitrification The process of releasing fixed nitrogen back to molecular nitrogen (N2). Nitrification The process of oxidizing ammonia to nitrites (NO2-) which are harmful to plants and then into nitrates (NO3-) which are beneficial.

4. Water Cycle • Human interventions • Ground and surface water depletion • Ground and surface water pollution • The clearing of vegetation, particularly in temperate and tropical rainforests, interferes with the cycle by decreasing transpiration • Hydrologic cycle is powered by the sun and gravity

5. Carbon Cycle • Since the industrial revolution, we have dramatically increased the CO2 in our atm due to: • Deforestation, which decreases the plants available for photosynthesis, thus decreasing CO2 uptake • Forest burning and returning the carbon in the biomass of the forest to the atm by releasing it from the sink • Increased combustion of fossil fuels, releasing carbon from the sink

6. Nitrogen • Some bacteria are capable of breaking the triple bond of nitrogen gas • Human Intervention • NO is released when fossil fuels are combusted. • NO forms nitric acid in atm making acid deposition • N2O gas is a greenhouse gas, from livestock waste and commercial fertilizer • Nitrogen starts eutrophication when added to water

7. Phosphorus • Very slow b/c there is no atm stage. • Nearly all is in rocks or living organisms, b/c ions do not dissolve well in water • Human Intervention • Phophate mines that form large pits can result in runoff pollution • Removing vegetation lowers phosphorus availability • Phosphorus addition can lead to eutrophication

8. Sulfur • Most sulfur found as iron disufide (pyrite) or as mineral salt: calcium sulfate (gypsum) • Released by weathering and volcanic activity • Human Intervention • Fossil fuel combustion, especially coal • Refining of petroleum and smelting • Coal mining damages aquatic ecosystems • Large amounts of sulfur dioxide and sulfate aerosols cool the atmosphere b/c they prevent UV radiation

9. Vocab/concepts • Law of tolerance: bell curve • Symbiosis • Mutualism: lichen (fungus and algae/cyanobacteria) • Parasitism: ticks, fleas • Commensalism: barnacles on a whale • Keystone species: abundance does not reflect importance- ie. Top predators

10. Vocab • Anthropogenic • From man • Biocentric • Environmental Justice • Intrinsic value • Negative feedback loops • Considered good • Positive feedback loops • Considered bad

11. Pyramids • Pyramid of biomass- the mass of living matter at each level • Pyramid of energy- how much energy is passed on at each trophic level • Reasons for lost energy • Can’t digest • May use more energy to catch food • Consumer may not eat entire killed organism • Loss to thermal energy • Average transfer is 10% range is about 80-95% • Pyramid of numbers -how many individuals at each trophic level • Can be inverted if a few trees supporting lots of insects and birds

12. Energy • Diffuse energy is considered low quality (ocean) • Concentrated energy is high quality (coal) • Potential energy is stored energy in food, etc • A calorie is the amount of energy needed to increase the temperature of 1 g of water 1°C • One calorie = 4.184 J (joules)

13. Thermodynamics • The study of energy conversion • The first law- Law of Conservation of Energy • Energy can neither be created not destroyed; it can only change from one form to another • The second law of Thermodynamics • With each energy conversion in a closed system, the energy change proceeds toward entropy • Disorganization is favored in nature • Stack of soda can example

14. Ecosystem Hierarchy • Individual • Species: group that reproduce fertile offspring • Population: a single species in an area • Community: group of interacting populations • Ecosystem includes biotic and abiotic factors • Biosphere

15. Evolution • Coevolution: selective pressures on each other • Selective pressures include: • Physiological stress, predation, competition and chance • Divergent Evolution • Adaptive radiation- Galapagos finches • Convergent Evolution • Lacks recent ancestor but develop similar features ie. Wings on a bird and wings on an insect • Competitive exclusion: two organisms cannot occupy the same niche for an indefinite period with out one eventually migrating, dying or undergoing resource partitioning.

16. Biomes • Tropics between 23°N and 23°S • Temperate between tropics and Polar • Polar region starts at 66°N or 66°S • Two most important aspects of climate are precipitation and temperature • Temperature cools as you move away from the equator • Altitude affects the biome-vertical zonation

17. Plants • Stationary, so adapted for weather • Succulents store water in stem • Stems might need to photosynthesize (spines) • Broadleaf evergreens keep their leaves all year (live oak) • Broadleaf deciduous-expend lots of energy to grow back leaves in the spring • Conifers-most evergreens, needles decrease water loss • Allelopathy- plants secrete toxins into soil

18. Aquatic Biomes • Freshwater Biomes • Rivers, streams, lakes, ponds and all inland wetlands including swamps, bogs, marshes and fens • Marine Biomes • Coral reefs, coastal marshes and swamps, estuaries, barrier islands and the open ocean

19. Aquatic Organisms • Plankton: float or swim weakly • Phytoplankton: cyanobacteria and algae • Zooplankton: herbivores and carnivores • Nekton: swim and are consumers • Sharks, tuna, bass and perch • Benthic: live on the bottom • Often decomposers or detritovores

20. Aquatic Limiting Factors • Nutrients • Dissolved oxygen • Temperature depth • Turbidity

21. Coral Reefs • Equivalent to tropical rainforest • Shallow, clear, warm water • Mutualistic relationship between a carnivorous cnidarians and an autotrophic alga • The coral polyps protect the algae within its tissues, algae provide food • Coral secrete shell of calcium carbonate • Reefs sensitive to pH change and increases in turbidity

22. Mangrove Swamps • Tropical trees that grow along coastlines • They function to catch sediment, remove nutrients, and serve to protect coastlines by preventing erosion • Large biodiversity • Serve as nurseries and nesting areas • Fallen leaves provide food for detritovores • Humans threaten mangroves by: • Use wood for lumber and charcoal • Aquacluture - raise saltwater species • Urbaninzation and coastline development

23. Estuaries • Where freshwater empties into salt water • Varying levels of salinity=brackish water • Tremendous biodiversity • Nutrient rich, turbid, large amounts of sediment • Flowing water may contain numerous pollutants-oil, nitrogen, phosphorus + fecal • High NPP and serves as a nursery for shrimp, oysters, clams and numerous nekton species • Humans interventions include • -recreation, fishing and aquaculture and development

24. Population Biology • Exponential Growth- J shaped curve • Growth without restrictions • r(N)=ΔN/ Δt [r=growth rate, N= number, t= time] • Same as biotic potential • Logistic Growth- S shaped curve • Carrying capacity(K): max pop that can be sustained indefinitely. It is not fixed. Changes by season. • ΔN/ Δt=rN(1-N/K) • Rule of 70 • Doubling time = 70/r

25. Environmental Resistance • Resistance increases with population • Density dependent factors • Disease, competition, predation and parasitism, territoriality, increased stress and aggression, decreased immunity and fertility • Density Independent factors • Floods, fires, hurricanes, human-induced disruption • Dispersion • Clumped, uniform, random

26. Selected strategists • Short life • Rapid growth • Early maturity • Many small offspring • Little parental care • Little investment in individual offspring • Adapted to unstable environment • Pioneers, colonizers • Niche generalists • Prey • Regulated mainly by extrinsic factors • Low trophic level • Long life • Slower growth • Later maturity • Fewer large offspring • High parental care • High investment in individual offspring • Adapted to stable environment • Later stages of succession • Niche specialists • Predators • Regulated mainly by extrinsic factors • High-trophic level R-selected K-selected

27. Survivorship • Natality-production of new individuals by birth, hatching, germination or cloning • Fecundity-physical ability to reproduce • Fertility-is a measure of the number of offspring produced by a female • Mortality- number that die in a particular time frame divided by the number living at the beginning of the time frame • Survivorship-proportion in a population that survive to a particular age. • Life expectancy-probable number of years of survival for an individual of a certain age • Life span- longest period of life reached by a given organism

28. Survivorship curves • Late-loss curve: more deaths in older organisms • Top consumers and K strategists • Constant-loss curve: death equal in all ages • Sea gulls, rodents, and some plants • Early-loss curve: probability of survival increases as these organisms age • Turtles and redwood trees • Type IV curve: early life mortality, which levels then rises again later • Deer and crabs