Distinguish Among the Following Types of Ecology

8/12/2019 Distinguish Among the Following Types of Ecology

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Distinguish among the following types of ecology:organismal, population, community, ecosystem, andlandscape-organismal: studies how an organism's structure,physiology, and

behavior meets environmental challenges--ex. How do hammerhead sharksselect a mate?-population: focuses on factors affecting how manyindividuals of a species live in an area--a population is a group of individuals of thesame species living in an area--ex. What environmental factors affect thereproductive rate of deer mice?-community: examines how interactions between

species (ex: predation,competition) affect community structure andorganization--a community is a group of populations ofdifferent species in an area--ex. What factors influence thediversity of species that make upa forest?-ecosystem: emphasizes energy flow and chemicalcycling betweenorganisms and the environment--an ecosystem is the community oforganisms in an area and the physicalfactors with which they interact--ex. What factors controlphotosynthetic productivity in atemperate grassland ecosystem?-landscape: focuses on factors controlling exchanges ofenergy, materials,and organisms across multiple ecosystems--a landscape is a mosaic of connectedecosystems--ex. To what extent do treeslining a river serve as corridors of dispersal foranimals?-global:examines how regional exchange of energy andmaterials influences the functioning and distribution of


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organisms across the biosphere--the biosphere is the global ecosystem, thesum of all the planet's ecosystems--ex. How does ocean circulation affectthe global distribution of crustaceans?

Explain how dispersal may contribute to a species'distribution-dispersal: movement of individuals away from theirarea of origin or from centers of high populationdensity--natural range expansions: when organisms reach anarea where they did not exist before (shows influence ofdispersal on distribution)

Distinguish between the following pairs of terms:potential and actual range, biotic and abiotic factors,macroclimate and microclimate patterns-potential range vs. actual range: for transplants to besuccessful, some of the relocated organisms mustsurvive and reproduce in the new area--if the transplant is successful, then the potentialrange of the speciesis larger than its actual range

--i.e. species could live in certain areas where itcurrently does not-biotic factors: other species that limit distribution--ex. beneficial interactions with other species such aspollinators for flowering plants--ex. negative interactions with other organisms such ascompetition and predation-abiotic factors: nonliving things that limit distribution--ex. temperature, water, sunlight, wind, rocks, andsoil

-macroclimate: patterns on the global, regional, andlocal level-microclimate: very fine patterns such as thoseencountered by the community organisms that livebeneath a fallen log


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Explain how a body of water or mountain rangemight affect regional climatic conditions-body of water: because of the high specific heat ofwater, oceans and large lakes moderate temperature ofnearby land

--during a hot day when land is warmer than water, airover the land heats up and rises, drawing a cool breezefrom the water across the land--at night, air over the warmer water rises, drawing coolair from the land back to the water, replacing it withwarmer air offshore-mountain range: affect sunlight reaching an area andthe local temperature and rainfall--when warm, moist air approaches a mountain, airrises and cools, releasing moisture on the windward

side of the peak--on the leeward side, cooler, dry air descends,absorbing moisture and producing a "rain shadow"

Define the following terms: photic zone, aphotic zone,benthic zone, abyssal zone, thermal stratification,thermocline, seasonal turnover, climograph,disturbance-photic zone: upper area where there is sufficient light

for photosynthesis (in aquatic biome)-aphotic zone: lower area where little light penetrates-benthic zone: substrate at the bottom of all aquaticbiomes made up of sand and organic and inorganicsediments-abyssal zone: part of benthic zone that lies between2,000-6,000 m below the surface of the ocean-thermal stratification: a change in the temperature atdifferent depths in the lake, and is due to the change inwater's density with temperature - cold water is denser

than warm water-thermocline: narrow layer of abrupt temperaturechange that separates the more uniformly warm upperlayer from the more uniformly cold deeper waters-seasonal turnover: semiannual mixing of water inlakes as a result of changing temperature profiles,which brings oxygenated water from the surface to the


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bottom and nutrient rich water from the bottom to thesurface in both spring and autumn-climograph: a plot of temperature and precipitation ina particular region-disturbance: an event (storm, fire, or human activity)

that changes a community, removing organisms from itand altering resource availability

List the major aquatic biomes-lakes-wetlands-streams and rivers-estuaries-intertidal zones

-oceanic pelagic zones-coral reefs-marine benthic zones

List and the major terrestrial biomes-tropical forest-desert-savanna-chaparral-temperate grassland

-northern coniferous forest-temperate broadleaf forest-tundra

Compare the vertical layering of a forest andgrassland-forest: layers from top to bottom consist of the uppercanopy, the low-tree layer, the shrub understory, theground layer of herbaceous plants, the forest floor, andthe root layer-grasslands: herbaceous layer of grasses and forbs, alitter layer, and a root layer

Define and distinguish between the following sets ofterms: density and dispersion; clumped dispersion,uniform dispersion, and random dispersion; life table


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and reproductive table; Type I, Type II, and Type IIIsurvivorship curves; semelparity and iteroparity; r-selected populations and K-selected populations-density: number of individuals-dispersion: pattern of spacing among individuals

within boundaries of population

-clumped dispersion: influenced by resources andbehavior - areas where there are several animals in agroup (ex. wolves)-uniform dispersion: evenly spaced out in territories(ex. penguins)-random dispersion: independent of other individuals(ex. dandelions - seeds blow everywhere in no specificdirection)

-life table: age-specific summary of survival pattern of apopulation-reproductive table: fertility schedule is an age specificsummary of reproductive rates of a population (basedon females)

-Type I survivorship curve: low death rates during earlyand middle life, then an increase among older agegroups, provide good care to offspring (ex. humans)-Type II: the death rate is constant over the organism'slife span (ex. rodents, vertebrates, lizards, and annualplants)-Type III: high death rates for the young, then a slowerdeath rate for survivors, little or no care for offspring(ex. fish, marine invertebrates, long-lived plants)

-semelparity: big-bang reproduction theory where anorganism reproduces once then dies (ex. salmon)-iteroparity: repeated reproduction (ex. lizards)

-r-selected populations: density-independent selection,selects for life history traits that maximize reproduction-k-selection populations: density-dependent selection,selects for life history traits that are sensitive topopulation density


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Explain how ecologists may estimate the density of aspecies-Mark-recapture method: mark species in a population

and let them back into their habitat, then recapturethem and see how many are marked (collect, mark,release, recapture)--100 are marked, capture 100, 1 is marked, populationis 1000

Explain how limited resources and trade-offs mayaffect life histories-life histories: evolutionary outcomes reflected indevelopment, physiology, and behavior

-trade-offs: animals with more offspring will die soonerthan animals with less because more offspring requiremore energy and resources to reproduce, support theoffspring, and take care of itself--affect the age reproduction begins, how oftenreproduction occurs, and how many organisms areproduced during reproductive cycle

Compare the exponential and logistic models ofpopulation growth

-exponential model: when populations increase underideal conditions of abundant food and the ability toreproduce--per capita rate of increase may assume maximum ratefor the species--results in J-shaped curve as population increases at aconstant rate--population accumulates more new individuals perunit of time when it is large than when it is small,making the curve steeper over timedN/dt = r(max)Nd=per capita death rateN=population sizet=timer(max)=maximum per capita rate of increase for thespecies


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-logistic model: per capita rate of increase approacheszero as the carrying capacity is reached--produces sigmoid (s-shaped) curve--new individuals are added to the population mostrapidly at intermediate population sizes, when there is

not only a breeding population of substantial size, butalso lots of available space and other resources in theenvironmentdN/dt = r(max)N((K-N)/K)K=carrying capacity(K-N)/K=fraction of carrying capacity that populationcan grow by

Explain how density-dependent and density-

independent factors may affect population growthdensity dependent: birth rate or death rate that doesnot change with population density-competition for resources: in crowded populations,increasing population density intensifies competitionfor declining nutrients, resulting in a lower birth rate-territoriality: becomes resource for which individualscompete, presence of surplus or non-breedingindividuals is a good indication that territoriality isrestricting population growth

-disease: transmission rate of a particular disease candepend on a certain level of crowding in a population-predation: predators encounter and capture more foodas population density of prey increases-toxic wastes: accumulation of metabolic by-productsas the population grows poisons the organisms-intrinsic factors: reproductive rate can drop due toaggressive interactions that increase with populationdensity, high population densities can induce a stresssyndrome in which hormonal changes delay sexual

maturation, causing reproductive organs to shrink anddepress the immune system

density-independent:-unusual weather-natural disasters-seasonal cycles


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-certain human activitiessuch as damming rivers andclear-cutting forests

Explain how biotic and abiotic factors may work

together to control a population's growthBiotic: Predation and competition can cause a decreasein population

Abiotic: Severe weather can cause extreme decreases

Describe the problems associated with estimatingEarth's carrying capacity for the human speciesThere is no single carrying capacity for the humanpopulation on earth - how many people our planet can

sustain depends on quality of life each of us enjoys andthe distribution of wealth across people and nations

Define the demographic transitioncompares the demographic transition in one of themost industrialized countries, Sweden, in a lessindustrialized country, Mexico-movement toward 2nd configuration:FROMzero population growth = high birth rate - high death

rateTOzero population growth = low birth rate - low death rate-also associated with increase in quality of health careand sanitation as well as improved access to education

Distinguish between the following sets of terms:competition, predation, herbivory, symbiosis;fundamental and realized niche; cryptic and

aposematic coloration; Batesian mimicry andMllerian mimicry; parasitism, mutualism, andcommensalism; endoparasites and ectoparasites;species richness and relative abundance; food chainand food web; primary and secondary succession-competition: (interspecific) (-/-) occurs whenindividuals of different species compete for a resource


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that limits their growth and survival--ex. grasshoppers and bison both compete for grass inthe Great Plains-predation: (+/-) one species, the predator, kills and eatthe other, prey

--ex. rattlesnakes find their prey with pair of heatsensing organs between their eyes and nostrils and theykill small birds by injecting them with toxins thru theirfangs-herbivory: (+/-) an organism eats part f a plant or alga--ex. cattle, sheep, and water buffalo-symbiosis: when two or more individuals live in directand intimate contact with one another--parasitism: (+/-) one organism, the parasite, derivesits nourishment from another organism, its host, which

is harmed in the process---ex. ectoparasites, which feed on the external surfaceof the host such as lice and ticks / endoparasites, whichlive within the body of their host such as tapeworms--mutualism: (+/+) benefits both species (ex. termitesin the digestive system of ruminant mammals)---obligate mutualism: at least one species has lost theability to survive without its partner---facultative mutualism: both species can survive alone-commensalism: (+/0) benefits one species but neitherharms nor helps the other (difficult to document)---ex. cowbirds and cattle egrets feed on insects flushedout of the grass by grazing herbivores

-fundamental niche: niche potentially occupied by thatspecies-realized niche: portion of fundamental niche thatspecies actually occupies in a particular environment

-cryptic coloration: camouflage, makes prey difficult tospot-aposematic coloration: warning coloration, such asthat of a poison dart frog

-Batesian Mimicry: a palatable or harmless speciesmimics an unpalatable or harmful model (ex. larva ofhawkmoth puff up its head and thorax when disturbed


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looking like the head of a poisonous snake)-Mullerian Mimicry: two or more unpalatable species,such as the cuckoo bee and yellow jacket, resembleeach other

-species richness: number of different species in thecommunity-relative abundance: proportion each speciesrepresents of all individuals in the community

-food chain: transfer of food energy up the trophiclevels from its source in plants and other autotrophicorganisms (primary producers) through herbivores(primary consumers) to carnivores (secondary, tertiary,and quaternary consumers) to decomposers

-food web: summary of trophic relationships of acommunity with arrows linking species according towho eats whom

-primary succession: process that begins in a virtuallylifeless area where soil has not formed, such as a newvolcanic island or on the rubble-secondary succession: occurs when an existingcommunity has been cleared by some disturbances thatleaves soil intact (ex. Yellowstone following the fires)

Define an ecological niche and explain thecompetitive exclusion principle in terms of the nicheconcept-ecological niche: sum of species' use of the biotic andabiotic resources in its environment-competitive exclusion: outcome that results from aslight reproductive advantage eventually leading to thelocal elimination of the inferior competitor

Explain how dominant and keystone species exertstrong control on community structure-dominant species: species that are most abundant orthat collectively have the highest biomass (total mass ofindividuals in a population) and exert powerful controlover occurrence and distribution of other species


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--ex. sugar maples have impact on abiotic factors suchas shading and soil, which affect other species that livethere-keystone species: not necessarily abundant in acommunity, but control structure though pivotal

ecological role or niche--ex. sea otters feed on sea urchins which mainly feedkelp - loss of sea otters (from whales) has allowed seaurchin population to increase and kelp to decrease

Distinguish between bottom-up and top-downcommunity organization-bottom-up: primary producers (plants) regulate thetrophic levels above them by the amount of food they

produce (presence or absence of mineral nutrientscontrols plant numbers, which control herbivorenumbers, which in turn control predator numbersN->V->H->P)-top-down: ecosystem is regulated by predation fromthe top of the food chain (predators limit herbivores,herbivores limit plants, and plants limit nutrientsduring growth and reproduction N


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Explain why species richness declines along anequatorial-polar gradient-evolutionary history: tropical communities are

generally older than temperate/polar communities(growing season is 5x as long in tropical forests as intundra with high altitudes)--intervals between speciation events run about 5x asfast in tropics as near the poles--many polar/temperate communities have "startedover" because of disturbances

-climate: solar energy input and water availability (highin tropics)

--evapotranspiration: evaporation of water from soilplus transpiration of water from plants - higher in hotareas abundant with rainfall than in low temp areaswith low precipitation--species richness correlates with both measure ofevapotranspiration

Define zoonotic pathogens and explain, with anexample, how they may be controlled-pathogens that are transferred from other animals to

humans, either thru direct contact or by means of anintermediate species called a vector (often parasitesincluding ticks, lice, and mosquitos)-can prevent zoonotic diseases by identifying keyspecies interactions involving pathogens and theirvectors and by tracking pathogen spread-ex. river blindness is caused by a nematodetransmitted by blackflies--controlled blackflies that spread the nematodes byusing an airplane to spray biodegradable insecticides

(ivermectin)

Explain how the first and second laws ofthermodynamics apply to ecosystems1. energy cannot be created or destroyed, but onlytransferred or transformed-we can account for the transfer of energy through an


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ecosystem from its input as solar radiation to its releaseas heat from organisms-transfers help determine how many organisms ahabitat can support and the amount of food humanscan harvest from a given site

2. every exchange of energy increases the entropy of theuniverse-some energy is always lost as heat-energy flowing thru ecosystems is dissipated intospace as heat, so if the sun were not continuouslyproviding energy to earth, ecosystems would vanish

Define and compare gross primary production, netprimary production, and standing crop

-gross primary production: the amount of light energythat is converted to chemical energy by photosynthesisper unit time

-net primary production: equal to gross primaryproduction minus the energy used by primaryproducers for respiration (R) (key measurementbecause it represents the storage of chemical energythat will be available to consumers in the ecosystem)--NEW bomass added in a group at a given time

NPP = GPP - R

-NPP is about 1/2 of GPP

-standing crop: TOTAL biomass of photosyntheticautotrophs present at given time

*Explain why energy flows but nutrients cycle withinan ecosystem

-Energy flow: Energy enters most ecosystems assunlight and is then converted to chemical energy byautotrophs, passed to heterotrophs through organicmolecules that make up food, and finally dissipated asheat- Nutrient cycling: Chemical elements, includingcarbon and nitrogen, are cycled among abiotic and


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biotic components of an ecosystem--photosynthetic organisms incorporate these elementsinto their biomass from the air, soil and water andsome of this biomass is then consumed by animals--the elements are returned to the environment by the

metabolism of plantsand animals, as well as by bacteria and fungi

Explain what factors may limit primary production inaquatic ecosystems-Light: the depth of light penetration affects primaryproduction in the photic zone of an ocean or lake--about of all solar radiation is absorbed in the 1st 15meters of water

--only ~5-10% of solar radiation may reach a depth of75 meters-Nutrients: more than light, nutrients limit primaryproduction in geographicregions of the ocean and in lakes--limiting nutrient is the element that must be addedfor production toincrease in an area--Nitrogen and phosphorous are typically the nutrientsthat most often limit marine production

---concentrations of these nutrients are very low in thephotic zone because they are taken up rapidly byphytoplankton and becausedetritus tends to sink--common in freshwater lakes---the addition of large amounts of nutrients fromsewage and fertilizer runoff from farms and yards tolakes has a wide rangeof ecological impacts---in some areas, sewage runoff has caused

eutrophication of lakes, which can lead to loss of mostfish species (eutrophication is the process in whichcyanobacteria and algae grow rapidly in response toincreased nutrientconcentrations, ultimately reducing oxygenconcentration)


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Distinguish between the following pairs of terms:primary and secondary production, productionefficiency and trophic efficiency-primary production: amount of light energy convertedto chemical energy by autotrophs during a given time

period in an ecosystem-secondary production: amount of chemical energy inconsumers' food that is converted to their own newbiomass during a given time period

-production efficiency: the percentage of energy storedin assimilated food that is not used for respiration-trophic efficiency: percentage of productiontransferred from one trophic level to the next--must always be less than production efficiencies

because they take into account not only energy lost thrurespiration, but also the energy is organic material in alower trophic level that is not consumed by the nexttrophic level--approx. 10%, so 90% of energy available at onetrophic level is not transferred to the next, which ismultiplied ver the length of the food chain (10% of theprevious 10% for the next level)

*Explain why worldwide agriculture could feed morepeople if all humans consumed only plant material-eating meat is an inefficient way of tappingphotosynthetic production-a person obtains more calories by eating grainsdirectly as a primary consumer than by eating the sameamount of grain fed to an animal

Describe the four nutrient reservoirs and theprocesses that transfer the elements between

reservoirs1.Water cycle-biological importance: essential for all organismsforms available to life: liquid, vapor, or frozen icereservoirs: oceans contain 97% water, 2% is bound inglaciers and polar ice caps, and 1% in lakes, rivers, andground water


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key processes: evaporation of liquid H2O by solarenergy, condensation of H2O vapor into clouds, andprecipitation, transpiration by plants moves volumes ofH2O into atmosphere, surface and groundwater canflow into ocean completing cycle

Carbon Cycle-biological importance: framework of organicmolecules essential to all organisms-forms available to life: photosynthetic organismsutilize CO2 during photosynthesis and convert carbonto organic forms used by consumers-reservoirs: fossil fuels, soils, sediments of aquaticecosystems, oceans, plant and animal biomass,atmosphere, sedimentary rock is the largest (limestone)

-key processes: photosynthesis by plants andphytoplankton remove atmospheric CO2 (equal toamount added by cellular respiration), volcanoes aresource, along with burning of fossil fuels

Nitrogen Cycle-biological importance: part of amino acids, proteins,and nucleic acid, and is a limiting plant nutrient-forms available to life: 2 inorganic forms areammonium and nitrate and organic forms are aminoacids, bacteria also use nitrite (animals only useorganic forms)-reservoirs: 80% is in atmosphere as nitrogen gas,others are soils and sediments of lakes, rivers, andoceans; surface and groundwater; and biomass of livingorganisms-key processes: entrance is nitrogen fixation(conversion of nitrogen gas by bacteria to forms thatcan be used to synthesize nitrogenous organiccompounds), also fixed by lightning; nitrogen fertilizer,precipitation, and blowing dust provides input ofammonium and nitrate; ammonification decomposesorganic nitrogen to ammonium; nitrification convertsammonium to nitrate by nitrifying bacteria;denitrification involves bacteria using nitrate as theirmetabolism instead of oxygen, releasing nitrogen gas


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Phosphorous Cycle-biological importance: major constituent of nucleicacid, phospholipids, and ATP, and bones and teeth-forms available to life: phosphate, which plants absorband use in the synthesis of organic compounds

-reservoirs: sedimentary rock (largest), soils, oceans(dissolved), and organisms-key processes: weathering of rocks adds phosphate tosoil, some may leach into ground and surface water andreach the sea; phosphate taken in by producers may beeaten by consumers; returned to sol or water throughdecomposition of biomass or excretion by consumers;dust and sea spray move small amounts thruatmosphere

Explain why toxic compounds usually have thegreatest effect on top-level carnivoresbiological magnification: process in which accumulatedtoxins becomes harmful as they become moreconcentrated in successive trophic levels of a food web--occurs because biomass at any given trophic level isproduced from a much larger biomass ingested fromthe level below

Describe the causes and consequences of ozonedepletion-results mainly from the accumulation of CFCs,chemicals used in refrigerators and in manufacturing--when breakdown products from these chemicals riseto the stratosphere, the chlorine reacts with the ozone,reducing molecular O2-thinning is most apparent over Antarctica and the holeis increased-increases intensity if UV rays reaching earth's surface,

increasing lethal and nonlethal forms of skin cancerand cataracts in humans

Distinguish between conservation biology andrestoration biology-conservation biology: seeks to preserve life andintegrates ecology, physiology, molecular bio, genetics,


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Distinguish between the total population size and theeffective population size-total population size: total number of organismsinhabiting an ecosystem-effective population size: the population's breeding

potential-- Ne = 4NfNm/Nf+Nm---Nf and Nm are the numbers of males and femalesthat can breed successfully

Describe the conflicting demands that mayaccompany species conservationConservation requires resolving conflict betweenhabitat needs of endangered species and human

demands-ex. US Pacific Northwest habitat preservation is atodds with timber and mining industries

Define biodiversity hot spots and explain why theyare important-a relatively small area with an exceptionalconcentration of endemic species and a large number ofendangered and threatened species-good choices for nature reserves, but are hard to

identify (could be a hot spot for more than onetaxonomic group)

Define zoned reserves and explain why they areimportant-an extensive region that includes areas relativelyundisturbed by humans surrounded by areas that havebeen changed by human activity and are used foreconomic gain-small Central American nation of Costa Rica hasbecome a world leader in establishing zoned reserves--Costa Rica has eight zoned reserves, called"conservation areas," which contain national park land--the buffer zones provide a steady, lasting supply offorest products, water, and hydroelectric power, as wellas support sustainable agriculture and tourism


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--Costa Rica hopes to maintain at least 80% of itsnative species in its zoned reserves

Explain the importance of bioremediation and

biological augmentation of ecosystem processes inrestoration efforts-bioremediation: use of organisms, usually prokaryotes,fungi, or plants, to detoxify polluted ecosystems--restoration ecologists use various types of organismsto remove many different types of toxins fromecosystems--ex. some plants adapted to soils containing heavymetals are capable of accumulating high concentrationsof potentially toxic metals

---restoration ecologists can use these plants torevegetate sites polluted by mining and then harvestthe plants to remove the metals from the ecosystem

-biological augmentation: uses organisms to addessential materials to a degraded ecosystem--encouraging the growth of plants that thrive innutrient-poor soils often speeds up the rate ofsuccessional changes that can lead to recovery ofdamaged sites

--ex. rapid regrowth of indigenous plants alongsideroads in Puerto Rico after colonization of the areas by anonnative plant that thrives on nitrogen-poor soils.---rapid buildup of organic material from the nonnativeplant enabled the indigenous plants to recolonize thearea and overgrow the introduced species

Describe the concept of sustainable development-development that meets the needs of people todaywithout limiting the ability of future generations to

meet their needs-must connect life sciences with social sciences,economics, and humanities

Explain the goals of the Sustainable BiosphereInitiative


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-define and acquire the basic ecological info needed todevelop, manage, and conserve Earth's resources asresponsibly as possible-studies global change, including interactions betweenclimate and ecological processes: biological diversity

and its role in maintaining ecological processes; andways in which productivity of natural and artificialecosystems can be sustained

Describe water and air near the equator-air is armer and less dense-air rises causing an open space in the atmosphere-cooler air gets pulled in and causes convection-falls as precipitation when air is too dense (cold)

-water gets warmer and top portion is blown by wind inits direction (affected by landforms and amount of sun)

Which direction does the wind blow in the northernhemisphere? Southern?-northern = right-southern = left--because of coriolis effect: nothing is blown straightbecause the earth is constantly spinning and because of

the angle of the earth at which it revolves around thesun

Describe the impact of wind patterns on an ecosystem-less water will evaporate with less heat, so lessprecipitation will occur

Define zero population growth-occurs when per capita birth and death rates are equal

(change in)N/(change in)t = rN

N=population sizet=timer=per capita rate of increase


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Define Shannon Diversity-calculation of organisms that can be in a certainpopulation

H=shannon diversity

H = -[(pA ln pA) + (pB ln pB) + (pC ln pC) + ...]

A, B, and C are the species in the community and p isthe relative abundance of each species

Distinguish Among the Following Types of Ecology

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