Topic 1 and 2

1.1.1 Outline the concept and characteristic of a system
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1st law: energy can be transferred and transformed but it can never be created nor destroyed
so all energy in living systems comes from the sun then into producers through photosynthesis, then consumers up the food wed

2nd law: with every energy transfer or transformation energy dissipates as heat so the energy available to do work decreases
which means there is always less energy at higher trophic levels
equilibrium is a sort of equalization or end point

a steady state equilibrium means constant changes in all directions maintain a constant state (no net change) which is common to most open systems in nature

static equilibrium means no change at all which does not exist

long term changes in equilibrium point do occur

equilibrium is stable (systems tend to return to the original equilibrium after disturbances)

generally maintained by negative feedback
positive feedback:
a runaway cycle
a change in a certain direction provides output that further increases that change
change leads to increasing change- it accelerates deviation

ex: albedo effect on global warming
1. temperature increases= ice caps melt
2. less ice cap surface area= less sunlight is reflected away from earth
3. more light hits dark ocean and heat is trapped
4. further temperature increase= further melting of the ice

negative feedback:
one change leads to a result that lessens the original change
self regulating method of control leading to the maintenance of a steady state equilibrium

ex. predator prey
snowshoe hare pop increases
more food for lynx= lynx pop increase
increased predation on hares= hare pop decline
less food for lynx= lynx pop declines
less predation= increase in hare population
models are:

used when we can't measure the real event

hard with the environment because there are so many interacting variables


may yield very different results from each other or actual events

there are always unanticipated possibilities including discontinuities, synergistic interactions, and chaotic events
2.1.2 Define trophic levelthe position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same position in food chains2.1.3 Identify and explain trophic levels in food chains and food webs selected from local environmentEstuary: producer: turtle grass primary consumer: grass shrimp secondary consumer: pin fish tertiary consumer: spotted sea trout quarternary consumer: osprey2.1.4 Explain the principles of pyramids of numbers, pyramids of biomass, and pyramids of productivity and construct pyramids from given datapyramids are graphic models of quantitative differences between trophic levels by second law of thermodynamics energy decreases along food webs pyramids are then narrower as they ascend however _of numbers ay be dif if large organisms are at low trophic levels like large forests &_of biomass may be dif if larger organisms are at high trophic levels like in open ocean2.1.5 Discuss how the pyramid structure effects the functioning of an ecosystemenergy is lost between each trophic level so less remains for the next level which affects respiration, homeostasis, movement, heat mass is also lost at each level which affects waste, shedding rarely more than 4 or 5 trophic levels vulnerability of top carnivores biomagnification2.1.6 Define the terms species, population, community, inch, and habitat with reference to local examplespopulation: a group of individuals of a certain species in a given area at a given time community: interacting groups of populations in an area species: a group of individuals who can interbreed to produce fertile, viable offspring niche: the role of an organism in its environment (multidimensional): nocturnal predator of small mammals in the forest habitat: where an organism typically lives2.1.7 Describe and explain population interactions using examples of named speciesintraspecific competition: competition between members of the SAME species for a common resource interspecific competition: 2 or more DIFFERENT species involved predation: members of one species feed directly on all or part of a living organism of a different species parasitism: one species feeds on part of another organism without killing it mutualism: symbiotic relationship were both species benefit commensalism: one species benefits the other is neither harmed nor helps2.2.1 List the significant abiotic (physical) factors of an ecosystemTerrestrial: Sunlight temperature wind latitude altitude fire frequency soil Aquatic: light penetration water currents dissolved nutrient concentrations salinity2.2.2 Describe and evaluate method for measuring at least three abiotic factorsinsolation: light meter temperature: thermometer soil moisture: tensiometer salinity: hydrometer dissolved oxygen: DO meter pH: pH probe turbidity: secchi disk2.3.2 Describe and evaluate methods for estimating abundance of organismsN=(#marked in first catch)(Total # in second catch)/(# of Recaptures in second catch) don't have to count every one best in closed environments moving organisms only N=(Mean # per quadrate)(total area)/(area of each quadrate) don't have to count every one quadrate placed randomly may never or rarely have targeted species sessile organisms only size must match the seize of organisms sampled2.3.3 Describe and evaluate methods for estimating the biomass of trophic levels in an ecosystemtake quantitative samples measure the whole habitat size dry samples to remove water weight take dry mass for sample then extrapolate to entire trophic level sample biomass/sample area=total biomass/total area it is based on the assumption that all individuals at the trophic level are the same, the sample accurately represents the whole habitat. But it prevents the killing of whole trophic level for measurement2.3.4 Define diversitythe number of different species and the relative number of individuals of each species2.3.5 Apply Simpson's diversity index and outline its significanceD=(N(N-1))/the sum of (n(n-1)) D=diversity index N=total #of organisms of all species n=#of individuals of particular species high D suggests stable and ancient low D suggest pollution, recent colonization, or agricultural management normally used in studies of vegetation but can be applied to comparisons of any species2.4.1 Define the term biomeregions of the earth characterized by specific climates and community types2.4.2 Explain the distribution, structure, and relative proclivity of tropical rain forests, deserts, tundra, and any other biometundra: precipitation:<15 cm/yr bitter cold low insolation gives short growing season 60-75 N latitude= northern North America, Asia, Greenland 20% of earth's surface simple structure low productivity temperate grasslands: precipitation: 25- 45 cm/ yr fire, drought, & animals prevent tree growth moderate insolation 9% of earth's surface simple structure medium to high productivity: rich soils Deserts precipitation:<25cm/yr may be tropical, temperate, and cold types: always extreme high to moderate insolation 30% of earths surface: between 30 degrees north and south of equator- Saraha (africa) Gobi(asia) and Majave(america) simple structure low productivity tropical rainforest precipitation: >150 cm/yr warm humid year round climate 80 F high insolation gives long growing season 23.5 N to 23.5 S= tropic of capricorn to cancer 2% of earth's surface South and central America, Central Africa, and SE Asia Complex structure-stratified layers high diversity- 50-80% of terrestrial species highest productivity of all terrestrial systems2.5.1 Explain the role of producers consumers and decomposers in an ecosystemproducer-through photosynthesis converts radiant to chemical energy consumer-must consume other organisms to meet their energy needs (herbivores, carnivores, scavengers, detritivores) Decomposers- break down organisms into impel organic molecules2.5.2 Describe photosynthesis and respiration in terms of inputs, outputs, and energy transformationphotosynthesis: inputs: sunlight, carbon dioxide, water outputs: sugars, oxygen matter transformations: inorganic carbon into organic energy transformations: radiant energy into chemical energy respiration: inputs: sugars, oxygen outputs: atp, carbon dioxide, water matter transformations: organic carbon compounds into inorganic carbon compounds energy transformations: chemical energy into carbon compounds into chemical energy as ATP2.5.3 Describe and explain the transfer and transformation of energy as it flows through an ecosystem30% solar energy reflected back into space 20% absorbed by clouds and atmosphere 50% remaining: warms troposhere and land, evaporates and cycles water, generates wind <.1% captured by producers for photosynthesis energy eventually transformed to heat and trapped by atmosphere eventually reradiated into space2.5.4 Describe and explain the transfer and transformation of materials as they cycle within an ecosystemwater cycle: transfers: precipitation, runoff, infiltration, percolation transformation: evaporation, condensation, melting organic storages: plants, animals inorganic storages: ocean, atmosphere, aquifer nitrogen cycle transfers: consumption, absorption transformation: nitrogen fixation, ammonification, denitrification, nitrification, assimilation organic storages: organisms, bacteria inorganic storages: soil, atmosphere, water, rocks carbon cycle: transfers: consumption transformations: assimilation, photosynthesis, respiration, combustion, decomposition, incomplete fossilization organic storages: plants, organisms inorganic storages: fossil fuels, atmosphere, rocks, water as carbonic acid2.5.5 Define the terms gross productivity, net productivity, primary productivity, and secondary productivitygross productivity: total biomass produced net productivity: otal biomass produced minus amount used by organism primary productivity: productivity at 1st trophic level secondary productivity: productivity at high trophic level gross primary productivity: rate at which prodders use photosynthesis to make more biomass net primary productivity: rate at which energy for use by consumers is stored in new biomass2.5.6 Define the terms and calculate the values of GPP and NPP from given dataGPP= amount of light energy converted into chemical energy by photosynthesis by photosynthesis per unit area per unit time NPP= GPP- R Standing crop= total living material at a trophic level2.5.7 Define the terms and calculate the values of GSP and NSP from given dataGSP= total gain by consumers in energy or biomass per unit are per unit time through absorption food eaten- fecal losses NSP= the gain by consumers in energy or biomass per unit time remaining after allowing for respiratory losses NSP=change in mass over time NSP=GSP-R BOD Bottles take 2 sets of sample measure the initial oxygen content Light and Dark in sunlight for period NPP=Light-Initial GPP=Light-Dark R=Initial-Dark hard in unproductive waters or short time GSP Measure the mass of food intake by an organism Measure the waste produced Intake-Waste=GSP NSP Measure organism's starting mass and ending mass Ending-Starting=NSP GSP difficult in natural condition NSP hard to document mass change in organism unless it is over a long period of time2.6.1 Explain the concepts of limiting factors and carrying capacity in the context of population growthcapacity for growth= biotic potential intrinsic rate of increase(r)= rate at which a population grows with unlimited resources environmental resistance= all factors which limit the growth of populations population size depends on interaction between biotic potential and environmental resistance carrying capacity= # of individuals of a given population which can be sustained infinitely in a given area carrying capacity established by limited resources in the environment only one needs to be2.6.2 Describe and explain s and j population curves2.6.3 Describe the role of density- dependent and density-independent factors and internal and external factors in the regulation of populationdensity dependent: effects based on amount of individuals in an area density independent: effects regardless of population density2.6.4 Describe the principles associated with survivorship curves including K and r-strategistsr selected: reproduce early, many young, few survive curve: die early but survivors lie FOREVER K-selected: reproduce late, few young, most survive curve: live young wild&free till all start to die constant loss: straight2.6.5 Describe the concept and process of succession in a named habitatecological succesion: the gradual change in species composition of a given area over time primary succesion: gradual establishment of biological communities on lifeless ground secondary succesion: reestablishment of biotic communities in an area where they already exist2.6.6 Explain the changes in energy flow, gross and net productivity, diversity, and mineral cycling in different stages of succession2.6.7 Describe the factors affecting the nature of climax communities