淡水生态学要点

1淡水生态学Freshwaterecology源自暨南大学水生所2淡水生态学Freshwaterecologyisthestudyofthestructure,function,andchangeoforganismsinfreshwatersasaffectedbytheirdynamicphysical,chemical,andbioticenvironments..3湖泊分区(Lakezones)沿岸带敞水带真光层透光层沉水植物浮叶植物挺水植物底栖带湖沼带4湖泊类型与起源5（一）构造湖Tectoniclakesbasinsformedbymovementsoftheearth’scrust（二）火山口湖Volcaniclakes（三）河成湖FluvialLakes6（四）牛轭湖7（五）堰塞湖Landslidelakeslakesformedbyrockslides,mudslidesdammingstreamsinvalleys8（六）冰川湖Glaciallakes是由冰川挖蚀成的洼坑和水渍物堵塞冰川槽谷积水而成的一类湖泊9（七）岩溶湖Solutionlakes•典型的岩溶湖是由碳酸盐类地层经流水的长期溶蚀所产生的岩溶洼地、岩溶漏斗或落水洞等被堵，经汇水而形成的一类湖泊。formedbytheslowdissolvingofsolublerockbywater.Mostformedinareaswithlimestonebedrock.10(八)海成湖Shorelinelakescreatedatirregularitiesorindentationsalongthecoastlineoflargelakes.Usuallyresultoflongshorecurrentsdepositingmaterialasaspitorbaratthemouthoftheindentation11（九）风成湖Aeolianlakesformedbywindactivityinaridregionswhichmayerodebrokenrockorredistributesandformingdune由风吹起的沙丘lakes.Generallytemporary.。12（十）人工湖Anthropogeniclakesdamsandexcavationsbyhumans13AnimalactivityBeaverDam14(十一)陨石湖Meteoritelakescraterfrommeteoriteimpacts,e.g.,largeoneinnorthernQuebec15Limnologicalmeandepth=V/AoMaximumdepth(zmax)16Relativedepth(zr)expressesthezmaxasapercentageofthemeandiameter平均直径ofthelake.17岸发展系数Shorelinedevelopment(DL)岸发展系数（岸线长与相同面积圆形湖泊岸线长之比）ShorelinedevelopmentiscalculatedasDL=L/(2*sqrt(*Ao))18河道及流域的主要特征河流长度L（km）：自河源沿河道至河口的长度称为河流长度，或称河长。落差：河段两端的河底高程差。10hhh19河网密度:单位面积内的河流总长度称为河网密度。它表示一个地区河网的疏密度。20河流连续体理论RCCRivercontinuumconcept由源头集水区的第一级河流起，河水向下流经各级河流流域，形成一个连续的、流动的、独特而完整的系统，称为河流连续体。21COMPARISONSOFAQUATICSYSTEMSCHARACTERISTICSTREAMS--RIVERSPELAGIAOFLAKESLITTORAL--WETLANDSSURFACEAREA/VOLUME(Linkagew/terrestrial)VERYHIGHLOWHIGHTEMPERATUREFLUCTUATIONSHIGH--MODERATE,DIELSTABLE,seasonalHIGHDIELMIXINGCONSTANTLYSEASONALFREQ.DIELTURBULENCE/WAVEACTIONHIGHLYSIGNIFICANTEFFECTSSHORELINEHIGHBOTTOMIMPACTSSTRUCTUREHIGH--MODERATELOWINPELAGICHIGHLIGHTAVAILABILITYCHANGESLONGITUDINALLY(Riparian)CHANGESW/DEPTHHIGHDISSOLVEDO2,RedoxUSUALLYHIGH(cfhyporheic)VARIESW/DEPTHDIELVARIATIONSEXTREMENUTRIENTSHIGH–MODERATELOW-MODVERYHIGH,SEDIM.®EN.CARBONSOURCESALLOCHTHONOUSAUTOCHTHONOUS(Periphyton)AUTOCHTHONOUSALLOCHTH.(Phytoplankton)AUTOCHTHONOUSALLOCHTHONOUS(Macrophytes+Periphyton)PRODUCTIVITYHIGHLOW--INTERMEDIATEVERYHIGHComparisonofAquaticSystems22Photosyntheticallyactiveradiation(PAR),i.e.,radiantenergybetween400~700nmwavelengths.Always46~49ofallenergy.23光在水中的传播Lightpenetration[,peni'treiʃən]inwaterThepercentageofthesurfacelightabsorbedorscatteredina1mlongverticalcolumnofwater,iscalledtheverticalextinctioncoefficient.Thisparameterissymbolizedbyk.24透明度TransparencyTransparency:Depthtowhichvisiblelightpenetrates25PhoticorEuphoticZone-extendsfromsurfacetodepthwherelightis1%ofincidentlightatsurface.RegionofnetO2productionduringthedayduetophotosynthesis(P/S)O2declinesduringnight-respiration(decompositionprocesses).AphoticZone-extendsfrombottomofphoticzonetobottomoflake.LightlevelstoolowforphotosynthesissorespirationprocessesdominateoverproductionprocessesandaphoticzoneusesO2.26CompensationDepth：depthatwhichincidentlightisreducedtoabout1%soP/S=respiration.27Epilimnion湖上层湖面温水层warmupperlayer;Metalimnion-layer斜温层水体变温层ofrapidchangeintemperature(e.g.,thermocline);Hypolimnion:均温层、深水层coldbottomlayer,about4℃;28Lakestratificationandseasonalturnover生态学意义29Thispattern(springturnover—summerstratification—fallturnover—winterstratification)istypicalfortemperate温带的深水湖泊deeplakes.30LAKEDEPTHMATTERSDeepLakesStratify分层ShallowLakesContinuousNutrientRecycling31水的特性Characteristicsofwater热容量很大热容量SpecificheatTheamountofheatrequiredtoraisetemperatureofaunitmassofasubstance1℃.32密度DensityNonlinear非线性relationofdensitytotemperatureisuniquetowater.Maximumdensityofpurewateris1.000g/cm3at3.94℃.Densityofpurewaterat0℃is0.99987g/cm3.Astemperatureincreasesbeyond4℃densitydecreasesatanincreasingrate.33Shiftfromlaminar层流toturbulent紊流flowinafluidinasmoothtubeisrelatedtotheviscosity粘度anddensityofthefluid,itsvelocity,andthesizeofthechannelortubethroughwhichthefluid流体flows.ReynoldsNumber雷诺系数,Re,isusedtodetermineifflowislaminarorturbulentinatube.Re=(pDv)/µpisdensity,Disthediameterofthechannelortube,visvelocity,andµisviscosity.Re1,000flowislaminar；Re1,000flowisturbulent.34surfaceseiches.35河水流RiverCurrents.Inflowmovementsrelatedtotemperature,dissolvedsubstances,andsuspendedparticles.363typesofinflowmovement:Overflow-riverwaterislessdensethanlakewaterandsostaysatthesurface,Underflow-riverwaterdensityisgreaterthanlakewaterandsoflowsalongthebottom,e.g.,springmeltrunoff.Interflow-riverwaterdensityisgreaterthanepilimnionbutlessthanmeta-orhypolimnion.37Thewatershed,alsocalledthedrainagebasin,isallofthelandandwaterareasthatdraintowardaparticularriverorlake.Thus,awatershedisdefinedintermsoftheselectedlake(orriver).Therecanbesubwatershedswithinwatersheds.Forexample,atributary支流toalakehasitsownwatershed,whichispartofthelargertotaldrainageareatothelake(orriver).38天然水体的pH值在6-8之间，是一个很好的缓冲体系，碳酸化合物是水体缓冲作用的重要因素。缓冲能力39溶解氧（D