普通生態(tài)學(xué)-2014lecture演替是指群落中物種的組成連續(xù)地、單方向

WeekSuccessionandCommunityresponsestoReadings:Ch.Ecological第、變化。這一順序被稱作是一個演替系"TheecologicalrelationsofthevegetationofthesanddunesofLakeCowlesaseriesof ntcommunitiesthatheinterpretedasahistoricalrecordofchangesinvegetation：startingwithafewhardy ntsgrowingonunstabledunesandculminatinginaclimaxcommunity(amature,balancedbiologicalcommunitywhosecompositionchangeslittleovertime)ofdeciduousgrowingonancientdunes.Cowlesdescribedthisprocessof ntsuccessionas ogoustothedevelopmentofanorganismfromembryotoadult,thoughhealsoemphasizedthatshiftingenvironmentalvariables(suchasduneslope,windspeedanddirection,moisture,andsoilchemistry)oftendisruptedthisdevelopmentalThus,inanidealizedscheme,theevolutionofthe ntcommunitywouldincreasethestabilityofthesanddune.Inreality,however,theduneoftenbrokeloose,destroyingthefinelytunedsymbiosisbetween ntsandsoil.Cowles’sworkdidmuchtoestablish“dynamicecology”asthecentralfocusof ntecologyduringthefirsthalfofthe20thcentury.Cowles’sphysiographicapproachex inedthedevelopmentanddistributionoflocal communitiesintermsoftopography,moisture,wind,erosion,sedimentation,andothergeologicalprocesses. TypesofPrimarysuccession（原生演替Secondarysuccession（次生演替GlacierMayMountSt.Helens

andshrubs1988, sofYellowstoneNationalTidal海三棱藨草群蘆葦群互花米草群 TerrestrialLakeorpondThegeneralIngeneral,communitiesinearlysuccessionwillbedominatedbyfast-growing,well-dispersedspecies(opportunist,fugitive,orr-selectedlife-histories).Assuccessionproceeds,thesespecieswilltendtobere cedbymorecompetitive(k-selected)species.TheClimaxAccordingtoclassicalecologicaltheory,successionstopswhentheserehasarrivedatanequilibriumorsteadystatewiththephysicalandbioticenvironment.Atthispointthecommunityisstableandself-replication.Barringmajordisturbances,itwillpersistindefini y.Thisendpointofsuccessioniscalledclimax.CharacteristicsofThevegetationistolerantofenvironmentalIthasawidediversityofspecies,awell-drainedspatialstructure,andcomplexfoodchains.Individualsintheclimaxstagearerecedbyothersofthesamekind.ThusthespeciescompositionmaintainsItisanindexoftheclimateofthearea.Thelifeorgrowthformsindicatetheclimatictype.TypesofClimaticClimax（氣候頂級群落EdaphicClimax（土壤頂級群落CatastrophicClimax 頂級群落Disclimax（人為頂級群落Subclimax（亞頂級群落TheoriesregardingnatureofMonoclimax（單元頂級）orClimaticClimaxTheorywasadvancedbyClements(1916)andrecognizesonlyoneclimaxwhosecharacteristicsaredeterminedsolelybyclimate(climaticclimax).Theprocessesofsuccessionandmodificationof etheeffectsofdifferencesintopography,parentmaterialofthesoil,andotherfactors.Thewholeareawouldbecoveredwithuniform community.Communitiesotherthantheclimaxandarerelatedtoit,andarerecognizedassubclimax,postclimaxandTheoriesregardingnatureofPolyclimaxTheorywasadvancedbyTansley(1935).Itproposesthattheclimaxvegetationofaregionconsistsofmoreonevegetationclimaxescontrolledbysoilmoisture,soilnutrients,topography,slopeexposure,fire,andanimalTheoriesregardingnatureofClimaxPatternTheorywasproposedbyWhittakeravarietyofclimaxes ernedbyresponsesofspeciespopulationstobioticandabioticconditions.thetotalenvironmentoftheecosystemdeterminesthecomposition,speciesstructure,andbalanceofaclimaxTheenvironmentincludesthespeciesresponsestomoisture,temperature,andnutrients,theirbioticrelationships,Thenatureofclimaxvegetationwillchangeastheenvironmentchanges.Theclimaxcommunityrepresentsapatternofpopulationsthatcorrespondstoandchangeswiththepatternofenvironment.Thecentralandmostwidespreadcommunityistheclimatic Flooding (1)最佳干擾時間（使生物量增加或種(2)無論對于生物量或種群數(shù)量來說， TheIntermediateDisturbanceHypothesis(IDH)statesthatlocalspeciesdiversityis izedwhenecologicaldisturbanceisneithertoorarenortoofrequent.Atlowlevelsofdisturbance,morecompetitiveorganismswillpushsubordinatespeciestoextinctionanddominatetheecosystem.Athighlevelsofdisturbance,due