Presentation on theme: "Part 1 Review. APES year in review 2009 Easter Island Sustainability - A system/process can continue indefinitely without depleting resources used. *no."— Presentation transcript:
Part 1 Review
APES year in review 2009
Easter Island Sustainability - A system/process can continue indefinitely without depleting resources used. *no sacrifice to future generations* Easter Island– flourishing population of 10,000+ used up islands trees faster than they could regenerate. Without trees, islanders couldn’t build canoes, fish, build homes, etc. People starved and within 300 years, only 2000 remained
Scientific Method 1. Define the problem (?) One that is testable. 2. Research 3. Hypothesis 4. Experiment -Variable (s) - Independent- (tested) * only one. - Dependent (measured) Valid – measures what it was intended to. Reliable- repeatable 5. Collect Data – Quantitative- numbers –-Qualitative- appearance 6. Conclusion 7. Report You may be asked to set up an experiment. (Need large trial groups) 10 +
Ecosystems Levels of organization of matter Universe Ecosphere/biosphere Ecosystems Communities Populations Organisms Cells Atoms
Plants and animals interacting with their abiotic environment. Ecosystems exist in biomes. Climate – av. temperature over time *Weather – daily variations in temp and precipitation Microclimate and Other Abiotic Factors * Light intensity * Soil type * Topography Ecosystems
Biomass and Biomass Pyramid All biomass gets its energy from the sun Only 10% of energy from one trophic level moves to the next trophic level Energy released is high potential energy molecules (like glucose) then converted to low potential energy molecules (like carbon dioxide) * concept of eating lower on the biomass pyramid
Ecosystem Diversity Biodiversity depends on: latitude (tropical is most diverse, polar is lowest. Depth in aquatic systems – diversity increases to ~ 2000m, then declines (in aquatic, diversity declines w/pollution)
Generalist species (R-species) have broad niches, and can survive in many places, a Specialist pecies (K-species) has a narrow niche, and can only survive under certain conditions. Keystone Species -species are more important than biomass suggests (ex: flying foxes/bat pollinate plants, elephants uproot trees creating forest openings, beaver dams) = stabilizing effect on ecosystem – Loss can lead to domino effect – loss of more and more species Indicator Species- indicates environmental changes. * frogs- water pollution. Invasive Species-(non-native) – Cane toad. Species
Relationships Mutualism * Flowers & insects Commensalism Parasitism Predator/prey Host/ Parasite Competition habitat vs. niche Competitive interactions Intraspecific competition – b/t members of the same species Interspecific competition – b/t 2 or more different species for food, space, etc. Interference competition – one may limit another’s access to some resource Explotative competition - one species can use a resource faster (exploit it) – humans do this often
Limiting Factors –Biotic & Abiotic Temperature, light, oxygen, carbon dioxide, precipitation Optimum levels Zones of stress Limits of Tolerance Range of Tolerance * Pond Water Gizmo Synergistic effects – The interaction of two or more factors is greater than the sum of the effects when each acts alone. Example: pollution and disease
Major Terrestrial Biomes: ecological communities adapted to climate of the region (most have ECOTONES). – Desert – near equator. hot & cold – Grassland– enough rain for grass to live, but not enough for big trees, -can be: » Tropical (savanna) – biggest in Africa = warm all year, 2 long dry seasons has lots of grazing animals) » Temperate (in the plains in N.&S. America =.cold winter, hot/dry summers, not much rain, so deep fertile soil, prairie grass) **often used to grow crops, can lead to erosion of soil. » Chaparral– temperate shrubland along coastal areas, naturally maintained w/periodic fires (people in this area – like CA, experience fire loss often)
» Tundra (v. cold, no trees, ice/snow, reindeer/caribou (don’t hibernate instead have thick coats), has spongy mat of short plants which grow during 6-8 weeks of sun) **contains permafrost – stays frozen year round and prevent liquid water from getting deep underground = marshy in the summertime. * Melting » Alpine tundra – above limit of tree growth, similar to arctic tundra, has no permafrost – Forest – mod. to high precipitation, lots of trees/smaller vegetation » Tropical Rainforest= lots of biodiversity (50-80% of terrestrial species), dead decompose quickly, little leaf litter, large canopy » Temperate (deciduous forest = avg. rain and change significantly during the seasons, deciduous forests (*lose leaves in winter) including: oak, hickory, maple, poplar, many plants at ground level – have been cleared to make tree plantations » Evergreen Coniferous (called boreal or taiga) = v. cold winters, short, mild summers, cone-bearing trees (*have leaves year-round, needle- shaped, waxy – ex: spruce, fir, cedar, hemlock, pine), low plant diversity, slow decomposition of leaf litter.
An ecotone is a transition area between two adjacent ecological communities. (ecosystems). Riparian
Aquatic Biomes: Oceans Euphotic zone (lighted upper zone w/photosynthesis, high DO, low nutrients, predatory fish), Bathyal zone (dimly lit middle zone, zooplankton/smaller fish). Abyssal zone (dark lower zone/little DO/lots of nutrients Upwelling / Nutrients Downwelling/ Oxygen
Lakes – littoral zone (shallow sunlit water near shore/to depth plants stop growing), – limnetic zone (open sunlit surface layer away from shore/produces food for the lake), – profundal zone (deep ocean water/too dark for photosynthesis), – benthic zone (bottom of lake inhabited by organisms that tolerate low DO and temp.)
Oligotrophic lake – nutrient poor lake Eutrophic lake – nutrient rich lake – sometimes caused by runoff of fertilizer (nitrates/phosphates into lake – cultural eutrophication
Freshwater streams/rivers Source zone (turbulent headwaters, lots DO, fish w/flattened bodies). Transition zone (headwaters merge = wider, deeper streams = more producers, lower DO) Floodplain zone (streams join into rivers that meander across valleys, higher temp, less DO, empty into ocean)
Energy flow - * very important / energy is most often stored in glucose. Photosynthesis: CO 2 + water + solar energy glucose + O 2 – Very inefficient (Only 1% of the energy from the sun is used) Cellular respiration – Aerobic resp.: Glucose + oxygen CO 2 + water + energy – Anaerobic respiration: breaking down glucose in the absence of oxygen – products are methane (CH 4 ), ethyl alcohol, acetic acid, hydrogen sulfide (H 2 S) * pew
Ecological succession – gradual change in species composition of a given area. Primary succession (can take thousands of years) Secondary succession (150-200 years) –
Fires in Ecosystem Maintain balance of species and energy in ecosystems over the long run. Beneficial b/c provide nutrients for soil. * grasslands We avoid natural fires, but the problems like Crown Fires- (not natural) kill the whole tree 1988 Yellowstone fires changed climax ecosystems of white bark pine trees to huckle berries. * Grizzlies eat both.
Carbon Cycle Carbon Cycle – based on CO 2 gas which makes up 0.0036% of our troposphere, important because it is a major component of the earth’s thermostat Movement of Carbon in the sea: » Soluble in water, so can stay dissolved in the sea » REMEMBER: the warmer the water, the LESS gas the water can hold, so as water warms, more CO 2 returns to the atmosphere. * Colder water holds more O 2 » Some removed by photosynthesis producers » Some reacts with seawater to form carbonate ions (CO 3 - 2 ) – which later can react with Ca ions to form CaCO 3 hardened shells of many sea creatures (when the organism dies, the shells can then be converted to limestone over time), plants in the sea can also die and over the years form fossil fuels.
Carbon Sinks-, sediments, oceans, biofauna.
Movement of Carbon on land: » Autotrophs – absorb CO 2 » Aerobic respiration –gives of CO 2 » Buried dead plants (over millions of years) are compressed, form fossil fuels (like coal/oil) when burned give of CO 2
Nitrogen cycle Main reserve in the atmosphere Living things must get N from ammonium (NH 4 ) or nitrate (NO 3 ) N from the atmosphere must be fixed Change N 2 into ammonium or nitrate – Rhizobium (bacteria living in roots of legumes) ---- Lightning – Burning fossil fuels * Industrial
Phosphorus cycle No gas phase, only solid and liquid. * Rocks Man-made fertilizers contain organic phosphates Because P is a limiting factor in aquatic systems, it leads to eutrophication. The rain forest is very good at recycling P, except when we cut it down…
Element Main nonliving reservoir Main living reservoir Other nonliving reservoir Human-induced problem Carbon C Atmosphere CO 2 Carbohydrates (CH 2 O)n And all organic molecules Hydro Carbonate (CO 3 -2) Bicarbonate (HCO 3 -) Litho minerals Global warming Carbon from fossil fuels underground are burned and released into the air as CO 2 Nitrogen N Atmosphere N 2 Proteins and other N- containing organic molecules Hydro Ammonium NH4+ Nitrate NO 3 - Nitrite NO 2 - Eutrophication Fertilizers contain human- made nitrates that end up in the water Phos- phorous P Lithosphere rocks as PO 4 -3 *no gas phase DNA ATP phospholipids Hydro Phosphate PO 4 - 3 Eutrophication Fertilizers contain human- made phosphates that end up in the water Cutting down rainforest stops recycling of P
Diversity ? Top 6 most abundant elements in living things (not in order) * NCHOPS Top 8 elements in the earths crust (in order) * O, Si, Al, Fe (iron), Ca, Na (sodium), P, Mg Only silly apes in college study past midnight.
Evolutionary Change Vocabulary that you need to know * DNA * Chromosome * Gene * Allele Central Dogma: DNA- blueprint RNA- carpenter Protein- house, wood
Cambrian Explosion- “Life” You are here. Geological time scale
Why do species change? Environmental resistance and biotic potential. Selective pressure on mutations. Speciation * creation of a new species based on reproductive isolation.
Evolution– the change in a population’s genetic makeup through successive generations - Microevolution – small genetic changes that occur in a population. » Occurs in species with genetic variation, one genetic variation is more adapted to survive, that genetic variation reproduces more, becomes more common (example: peppered moth) natural selection -Macroevolution – long-term, large-scale evolutionary changes, leads to a new species forming and the other species being lost to extinction. -Co-evolution – occurs when two populations of two different species interact over a long period of time, changes occur in the gene pool of one species lead to changes in the other » Usually occurs with carnivores: Owls that have better eyesight can catch more mice, so they thrive mice that run faster avoid being eaten by the owls.
Mutations Mutations (changes) are naturally random events. * Normal variation- diversity of organisms * Chemical * UV * Radiation * Genetic Trait- only passed down if an organism reproduces. “Survival of the Fittest”
Natural Selection –Directional – changing environmental conditions cause individuals at one end average to become more common than mid-range – “it pays to be different” -Stabilizing – eliminates individuals on either end of genetic spectrum, favors individuals w/avg. genetic makeup – “pays to be average” -Diversifying – environmental conditions favor individuals at both extremes – “it does not pay to be normal”
Figure 9-1 Earth’s water supply Water
Water Facts The primary use for fresh water in U.S. is for agriculture. In our homes, we use the most fresh water to wash, clean and flush. The typical person in an industrialized nation uses 700-1000 gallons per week!
World Fresh Water Supply Largest lake 20 %. of fresh water. Lake Baikal, Russia 4000 Miles
Water cycle – powered by the sun and gravity, a natural cycle that acts to purify water **only cycle that does NOT involve a chemical reaction (only a physical change of state) Evaporation (liquid water to water vapor) – Transpiration (liquid water on leaves/roots into water vapor) – Condensation (water vapor to liquid water – clouds/fog) – Precipitation (rain/sleet/hail/snow) – Infiltration (liquid water into the soil) – Percolation (downward flow of water into the soil and aquifers) – Runoff (down slope surface movement of water back to the sea to resume the cycle)
Human effects on the Hydrologic Cycle Figure 9-3 The Hydrologic cycle Anthropogenic
Aquifer -S-Salt water intrusion
Rain shadow Figure 9-6 Rain shadow
Mono Lake Excellent example of human interference with the water supply. The water in the lake was diverted from the lake to the city of Los Angeles. It became a salt bed. ↑ Salt concentration due to evaporation
Three Gorges Dam in China China needs to meet the growing demand for energy Huge environmental impact Hundreds of thousands of people will be displaced (not to mention the ecosystems which will be flooded)