生態(tài)學(xué)(英文版)

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Ecology(生態(tài)學(xué))

Introduction

Ecology--__________________________________________________________

Conceptoftheecosystem-Thebiosphereandbiomes

?Bioshpere生物圈

oThepartoftheEarthanditsatmosphereinhabitedbylifeiscalledbiosphere

oThus,theoceans,landsurfaceandlowerpartsoftheatmosphereallformpartsofthebiosphere.

?Biome生物群落

oThebiospherecanbedividedintobiomeswhicharelinkedbyacommontypeofvegetation.

oForests,desertsandgrasslandsaretheexamplesofbiomes.Eachbiomeconsistsofmanyecosystemsinwhichcommunitieshaveadaptedtodifferencesinclimate,soil,andotherenvironmentalfactorsthroughoutthebiome.

A.TheEcosystem生態(tài)系統(tǒng)

Anecosystemisdefinedasacomplexformedbythelivingcommunityofdifferentspeciesinteractingwithoneanotherandwiththeirnon-livingenvironmentofmatterandenergytoresultinastableandself-sustainablesystem.

Componentsofanecosystem:livingcommunityandnon-livingcomponent

?Apopulation種群consistsofallmembersofthesamespeciesoccupyingagivenareaatthesametime.

?Acommunity群落consistsofPopulationsofallthedifferentspeciesinteractingwithoneanother

?Ahabitat生境isasmallspecificplacewhereanorganismlives.

-typesofhabitats:

terrestrialhabitatforest,___________________

aquatichabitatfreshwater:pond,lake,reservoir,__________?marine:sandyshore,muddyshore,___________________

Ahabitatcandivideintonumerousmicrohabitats小生境,each

with________________

_____________________________________________________________________

?Theniche生態(tài)位ofaspeciesdescribestheroleofspecificspeciesinitscommunity.

Nichesaresometimesdistinguishedfromhabitatsbysayingthatthehabitatofan

organismisitsaddress,whileitsnicheisitsroleinthecommunity.

e.g.onatree:caterpillars(feedonleaves),

beetles(burrowintotrunk)

theyliveonsameplacebutfunctionallytheyoccupydifferentniches.

?Thebiotic(living)factors生物的arecomprisedbyalllivingorganismswithintheecosystem.

?Theabiotic(non-living)非生物的factorsaremainlydividedintosoil,waterandclimate.

oWaterisessentialforalllivingorganismsinthesoilandenterslivingcellsbyosmosis.

oSoilsvaryintheircontentofclay,silt,sandandgravel.Thecompositionofsoildeterminesthesoiltexture,porosity,water-retainingcapacityandoxygencontent.

Soilcontainsamixtureoforganicandinorganicnutrients(humusandminerals).

oClimateincludesenvironmentalvariablessuchaslight,temperature,moisture,salinityandwind.Thesefactorsareimportantindeterminingthetypesofliving

organismsintheecosystem.

B.Energyflowandnutrientcyclingintheecosystem

I)Transferofenergy(manyapproaches,accordingtofunctionsinecosystem)

Foodchain

Alinearsequenceoforganismsshowingapathwayoffoodconsumptionfromproducersthroughaseriesofconsumers.Inthisseries,anorganismfeedsontheonebeforeitandformsthefoodoftheorganismafterit.

Foodchainsareshort(4-5levels)becauseonly10-20%ofenergyistransferredtothenextstage.

Eachstageinfoodchain=_______________

Trophiclevels

?Thenumberofstepsbywhichtheorganismsobtaintheirenergyfromplantsinafoodchain.theproducersalwaysatthefirsttrophiclevel.

______consumers______consumers

a)Producers:autotrophs自養(yǎng)--photosynthetice.g.greenplant,photosyntheticbacteria,

chemosyntheticbacteriae.g.nitrifyingbacteria,

baseoffoodchainandfoodweb.

N.B.:Phytoplanktons,whicharemicroorganisms,areimportantproducersfloatingontheupperlayersoflakesorocean.Theyareunicellular

organismswhichalsocontainchloroplaststocarryoutphotosynthesis

justliketheterrestrialplants.

b)Primaryconsumers:herbivoreswhichfeedonplantse.g.pondsnails,insectlarvae.

c)Secondaryconsumers:carnivoreswhichfeedonprimaryconsumerse.g.smallfish.

d)Tertiaryconsumers:largercarnivoreswhichfeedonsecondaryconsumerse.g.largefish

e)Decomposers:mainly________________________,

分解者decomposedeadbodiesofplantsandanimalsintosimplercompounds

whichcanthenbeabsorbedbygreenplantsagain,

importantinrecyclingofnutrientsandclearingupdeadbodiesand

excretoryremains.

f)Detritivores:consumethelossesfromthefoodchain,ordeadorganicmatterdetached

食腐質(zhì)動(dòng)物fromdeadbodiesorexcreta(detritus),movementofenergyandmatterinacontinuousmanner,thereforehardtodefinetrophiclevel,

mainlybacteria,fungi,protozoans,insects,mitesandsomesmall

vertebrates,

detritusdetritivorescarnivoresandherbivores

Importances:

?detritivoresbreakdowncomplexcompoundstosimplermolecules,thereforespeeding

updecompositionofdeadbodiesandexcretoryremainsbybreakingupdetritusintosmallpiecesthusincreasingthesurfaceareaavailableformicrobialaction,

?addingproteinsandmicroorganismsontothesoilbytheirfaeces

g)otherdefinitionsystem:

Producerherbivorescarnivorestopcarnivores

(prey)(prey/predator)(predator)

Someanimalsmayactasbothherbivoreandcarnivore:omnivore

Foodweb

-2ormoreinterconnectingfoodchains,eachorganismmayhavedifferenttrophiclevels營養(yǎng)層indifferentfoodchainwithinafoodweb.

-examplesofwoodlandandfreshwaterhabitat(refertoanytextbook)

Exampleoffoodweb:Marsh

II)Leveloforganization

Arrangethefollowingecologicaltermsinorder:

biosphere,community,population,organ,organism,biome,cell

Species:____________________________________________________________________________________________________________________________________

III)Ecologicalenergetics

Production:amountofmaterialswhichaccumulateoverafixedamountoftime.

Topcarnivores

Carnivores

decomposers

Herbivores

Greenplants

N.B.Muchofthesolarenergyreachingtheplantislostbyreflectionandphotosyntheticinefficiency.

Usefulterms:

?Biologicalproductivity生物生產(chǎn)力istherateatwhichbiomassisproducedbyanecosystem.Ithastwocomponents:

oPrimaryproductivity初級生產(chǎn)力,theproductionofneworganicmatterbygreenplants(autotrophs).

oSecondaryproductivity次級生產(chǎn)力,theproductionofneworganicmatterbyconsumers(heterotrophs).

?Bothofthesecanbedividedintogrossprimaryproductivityandnetprimaryproductivity.