BBC经典-《行星地球》英文解说词(全集)

行星地球英文解说词第1集PLANETEARTHFromPoletoPoleAhundredyearsagotherewereoneandahalfbillionpeopleonEarth.Now,oversixbillioncrowdourfragileplanetEarth.Butevenso,therearestillplacesbarelytouchedbyhumanity.ThisserieswilltaketothelastwildernessesandshowyoutheplanetEarthanditswildlifeasyouhaveneverseenthembefore.Imagineourworldwithoutsun.MaleEmperorpenguinsarefacingthenearestthatexistsonplanetEarthEarth-winterinAntarctica.It'scontinuouslydarkandtemperaturesdroptominusseventydegreescentigrade.Thepenguinsstaywhenallothercreatureshavefledbecauseeachguardsatreasure:asingleeggrestedonthetopofitsfeetandkeptwarmbeneaththedownybulgeofitsstomach.Thereisnofoodandnowaterforthem,andtheywillnotseethesunagainforfourmonths.Surelynogreaterordealisfacedbyanyanimal.AsthesundepartsfromtheAntarcticitlightenstheskiesinthefarnorth.It'sMarchandlightreturnstothehighArctic,sweepingawayfourmonthsofdarkness.Apolarbearstirs.Shehasbeeninherdenthewholewinter.Heremergencemarksthebeginningofspring.Aftermonthsofconfinementundergroundshetoboggansdowntheslope.Perhapstocleanherfur,perhapsforsheerjoy.Hercubsgazeoutoftheirbrightnewworldfortheveryfirsttime.Thefemalecallsthem,butthissteepslopeisnottheeasiestplacetotakeyourfirststeps.Buttheyarehungryandeagertoreachtheirmother,who'sdelayedfeedingthemonthisspecialday.Nowsheluresthemwiththepromiseofmilk,theonlyfoodthecubshaveknownsincetheywereborndeafandblindbeneaththesnowsometwomonthsago.Theirmotherhasnoteatenforfivemonthsandhaslosthalfherbodyweight.Nowsheconvertsthelastofherfatreservesintomilkforhercubs.Thespringsunbringswarmthbutalsoaproblemforthemother.Itstartstomelttheseaice.Thatiswhereshehuntsforthesealsheneedstofeedhercubs.Andshemustgettherebeforetheicebreaksup.Fornowthoughit'sstillminusthirtydegreesandthecubsmusthavetheshelteroftheden.It'ssixdayssincethebearsemergedandspringisadvancingrapidly.Butevennowblizzardscanstrikewithoutwarning.Beingsosmall,thecubsareeasilychilledandtheywillbemorecomfortablerestingintheden.Buttheirmothermustkeepthemoutandactive.She'sbecomingweakfromhungerandthere'snofoodonthesenurseryslopes.Theseaicestillholdsfirm,butitwon'tlastmuchlonger.Day10,andthemotherhasledhercubsamilefromtheden.It'stimetoputthemtothetest.They'vegrownenormouslyinconfidence,buttheydon'thavetheirmother'ssenseofurgency.Atlastitseemsthatthey'rereadyfortheirjourneyandthey'reonlyjustintime,forafewmilesfromthecoasttheiceisalreadysplitting.Nowthemothercanstarthuntingforthesealstheymusthave,butshe'sleadinghercubsintoadangerousnewworld.Nearlyhalfofallcubsdieintheirfirstyearoutontheice.Summerbrings24hoursofsunlightandthethawingshiftinglandscape.FurthersouththewintersnowshavealmostclearedfromtheArctictundra.NorthernCanada'swildfrontier.Herenaturestagesoneofhergreatestdramas-EveryyearthreemillioncariboumigrateacrosstheArctictundra.Theimmensityoftheherdcanonlybeproperlyappreciatedfromtheair.Someherdstravelover2,000milesayearinsearchoffreshpastures.Thisisthelongestoverlandmigrationmadebyanyanimal.They'reconstantlyonthemove.Newborncalveshavetobeupandrunningthedaytheyareborn.Butthevastherdsdonottravelalone.Wolves.Packsofthem,eighttotenstrong,shadowthemigration.Andtheyarehungry.It'sthenewlyborncalvesthattheyareafter.Runningdirectlyattheherdisaploytogeneratepanic.Theherdbreaksupandnowit'seasiertotargetanindividual.Inthechaosacalfisseparatedfromitsmother.Thecalfisyoung,butitcanoutrunthewolfifonlyitmanagestokeepitsfooting.Atthisstagetheoddsareeven-eitherthecaribouwillmakeamistakeorafteramilethewolfwillgiveup.Midsummeronthetundraandthesundoesnotset.Attheselatitudesthesun'sraysareglancingandnotenoughoftheirenergyreachesthegroundtoenabletreestogrow.You'llneedtotravel500milessouthfromherebeforethatispossible.Thesestuntedshrubsmarkthetreeline-thebeginningoftheborealforest-thetaiga.Theneedle-shapedleavesoftheconifersarevirtuallyinediblesothisforestsupportsverylittleanimallife.It'sasilentplacewherethesnowisunmarkedbyfootprints.IntheArcticwintersnowformsacontinuousblanketacrosstheland.Butasspringcreepsupfromthesouththetaigaisunveiled.ThisvastforestcirclingtheglobecontainsathirdofallthetreesonEarthandproducessomuchoxygenitchangesthecompositionoftheatmosphere.Aswetravelsouthsothesun'sinfluencegrowsstrongerandat50degreesoflatitudearadicaltransformationbegins.Summersherearelongenoughforbroadleaftreestoreplaceconifers.Broadleavesaremucheasiertoeatanddigestsonowanimalscancollecttheirshareoftheenergythathascomefromthesun.It'ssummerandtheseforestsarebustlingwithlife.Butthegoodtimeswillnotlast.Broadleavesmustbeshedinwinterfortheirdamagebyfrost.Astheydisappear,sothelandbecomesbarrenwithlittleforanimalstoeat.Theinhabitantsmustmigrate,hibernate,orfacemonthsofnearstarvation.TheAmurleopard-therarestcatintheworld.Here,inthedeciduousforestsofeasternRussiathewintermakeshuntingverydifficult.Prayanimalsarescarce,andthere'snoconcealingvegetation.Thecubisayearoldandstilldependentonitsmother.Deerarefrequentcasualtiesoftheharshwinterandtheseleopardsarenotabovescavengingfromacorpse.Africanleopardscouldneversurvivehere,buttheRussiancatshavethickfurtoshieldthemfromthecold.ThereareonlyfortyAmurleopardsleftinthewildandthatnumberisfalling.Likesomanycreatures,thecatshavebeenpushedtotheveryedgeofextinctionbyhuntingandthedestructionoftheirhabitat.TheAmurleopardsymbolisesthefragilityofournaturalheritage.Thefutureofanentirespecieshangsonsurvivalofatinynumberofmotherslikethisone.Allanimals,rareorcommon,ultimatelydependfortheirenergyonthesun.InJapanthearrivalofthecherryblossomannouncesthebeginningofspring.Thesun'senergybringscolourtothelandscape.Theearth,asitmakesitsannualjourneyaroundthesun,spinsonatiltedaxis.Andit'sthistiltthatcreatestheseasons.Theadvanceoftheseasonsbringsconstantchange.Asthesun'sinfluencediminishesinthenorth,sothedeciduousforestsofAmericabegintoshutdownlosingtheirleavesinpreparationforthedarkcoldmonthsahead.Oneseasonhandsovertoanother.Someorganismsthriveondecay,butmostmustmakespecialpreparationsforwinterandalifewithlittlesun.Wholepopulationsofanimalsarenowforcedtotravelgreatdistancesinpursuitoffoodandwarmth.300,000BaikaltealgathertoescapefromtheSiberianwinterbymigratingsouthtoKorea-theworld'sentirepopulationinasingleflock.Buttherearepartsoftheworldthathavenoseasons.Inthetropicsthesun'sraysstriketheearthheadonandtheirstrengthismoreorlessconstantallyearround.Thatiswhythejunglegrowssovigourouslyandsupportssomuchlife.Thisforestcoversonly3percentoftheplanet'ssurface,butitcontainsmorethan50percentofallitsplantsandanimals.Thecanopyisparticularlyrich.Therearemonkeys,birdsandmillionsofspeciesofinsects,exactlyhowmanywehavenoidea.Thecharacteroftheforestchangesaswedescend,becomingeverdarkeranddamper,favouringdifferentkindsofanimalsandplants.Lessthan2percentofthesunlightreachesthefloor,butevenherethereisextraordinaryvariety.InthegreatislandofNewGuineathereare42differentspeciesofbirdsofparadise,eachmorebizarrethanthelast.Thisforestissorichthatnourishingfoodcanbegatheredveryquickly.Thatleavesthemalesix-plumedbirdofparadisewithtimetoconcentrateonothermattersliketidyinguphisdisplayarea.Everythingmustbespickandspan.Allisready.Veryimpressive,butnooneiswatching.Thesuperbbirdofparadisecallstoattractafemale.Andhehasmoreluck.Butwhatdoeshehavetodotoreallyimpressher?Sheretirestoconsiderherverdict.It'shardnottofeeldeflatedwhenevenyourbestisn'tgoodenough.Thesuninfluenceslifeintheoceansjustasitdoesonland.Itsrichestpartsarethosewherewavesandcurrentsbringfertilisingnutrientstosurfacewatersthatarebathedinsunlight.TheseasofftheCapeinSouthAfricahavethismagicrecipeandarehugelyproductive.Summeristhetimeofplentyandit'snowthatthesealsstarttobreed.Thestrikeofagreatwhitesharklastsameresecond.Slowingitdownfortytimesrevealsthetechniqueandimmensestrengthofthismassivepredator.Ifsurprisefails,therewillbeachase.Thesharkisfasteronastraightcoursebutitcan'tturnassharplyastheseal,itsagilityversuspower.Oncethesealshavefinishedbreedingthegiantsharkswillmoveon.It'snowbecomingclearthatgreatwhitesmigratethousandsofmilesacrosstheoceanstoharvestseasonalabundancesindifferentseas.Thesun,beatingdownontropicalwaters,powerstheweathersystemsoftheglobe.Moistureevaporatesfromthewarmingoceanandrisestocreategreatstorms.Thewindsgeneratedoutatseasweepinlandacrossthecontinents.AstheytravelacrosstheSaharatheycreatethebiggestofallsandstormsblowingsandhalfwayroundtheworldtofertilizetheAmazonjungle.WindsblowingacrosstheIndianOceancollectmoistureandsweepnorthwardstowardstheHimalayas.Astheairrises,soitcools.Thewateritcarriescondensesintocloudsandthenfallsasthelifegivingrainsofthemonsoon.Soaircurrentspoweredbythesuncarrywetairtothemiddleofcontinents.Withoutwatertherecanbenolife,butitsdistributionoverthelandisfarfromeven.Desertscoveronethirdoftheland'ssurfaceandthey'regrowingbiggereveryyear.ThisistheKalahariDesertinSouthernAfrica.It'sthedryseasonandthousandsofelephantshavestartedtotravelindesperatesearchforwater.AllacrossSouthernAfricaanimalsarejourneyingforthesamereason.Buffalojointhegreattrek.NowhereelseonEartharesomanyanimalsonthemovewiththesameurgentpurpose.They'reallheadingfortheswampsoftheOkavango,avastinlanddelta.Atthemomentitisdry,butwateriscoming.Thetravellersarehamperedbydangerousduststorms.Femalesandcalvescaneasilygetseparatedfromthemainherd.Forthispairsanctuaryliesinthepatchofwoodlandafewmilesahead.Theycan'trestuntiltheyreachit.Themainhasalreadygottheresafely.Finally,thestragglersemergefromthedust.Theexhaustedcalfisstillblindedbysand.Itsmotherdoeseverythingpossibletohelpit.Thestormisnowsubsiding,butnotalltheelephantshavebeensolucky.Oneyoungsterhasgotlost.Thirstyandexhausted,itfollowsthetracksofitsmother,butsadlyinthewrongdirection.AtthepeakofthedryseasonintheKalahariwaterarrivesintheOkavango.ItfellasrainathousandmilesawayinthehighlandsofAngolaandhastakennearlyfivemonthstoreachhere.Thewaterdrivesoutinsectsfromtheparchedground,whicharesnappedupbyplovers.Catfish,travellingwiththeflood,collectanydrowningcreaturesthebirdshavemissed.It'saseasonalfeastforanimalsofallkinds.Birdsarethefirsttoarriveinanynumbers-watercranes,thenblackstorks.Behindthebirdscomebuffalo.Afterweeksofmarchingtheirtrekiscomingtoanend.AsthewatersweepsintotheOkavangoavastareaoftheKalahariistransformedintoafertileparadise.NowhereonourplanetEarthisthelifegivingpowerofwatersoclearlydemonstrated.TheOkavangobecomescriss-crossedwithtrailsasanimalsmoveintoitsheart.Thenewarrivalsopenuppathslikearteriesalongwhichwaterflows,extendingthereachoftheflood.ThisisanAfricararelyseen-alushwaterworld.Somecreaturesarecompletelyathomehere.Thesearelechwe-antelopewithhoovesthatsplaywidely,enablingthemtomoveitsspeedthroughthewater.Forothersthechangeisfarlesswelcome.Baboonsaresomewhatapprehensivebathers.Thewaterbringsaseasonofplentyforallanimals.Huntingdogs.ThesearenowamongtherarestofAfrica'smammals,butthennonethelessthecontinent'smostefficientpredators.Theirsecretisteamwork.Impalaaretheirfavouriteprey.Theystarttohuntandthepacksplitsup.Anaerialviewpointgivesanewinsightintotheirstrategy.Asthedogsapproachtheirpreytheypeelofftotakeupseparatepositionsaroundtheirtarget.Theyseemtoformacordonaroundtheimpala.Movingintotalsilencetheytakeuptheirpositions.Thoseearscandetecttheslightestrustle.Thehuntison.Threedogscloseinononeimpala.Missed.Theleaddogdrivestheimpalatowardsthehiddenflankers.Anticipatingtheirlinetheleadercutsthecornerandjoinsaflankerforthefinalassault.It'sallornothing.Oneonone.Thedoghasstamina,theimpalahasspeed.Leapingintothelakeisanactofdesperation-impalacanbarelyswim.Thedogsknowtheirpreymustcomeoutordrown-nowit'sawaitinggame.Therestofthepackarecalling.They'vemadeakillintheforestandthisisaninvitationtojoininthemeal.Theimpalaisinluck.Apackthissizekillsonceadayandeverythingisshared.Andthisimpalaisreprieved.Theelephantsarenearingtheendoftheirlongjourney.Afterweeksofmarchingthey'redesperatelytired.Thematriarchcansmellwaterandencouragestheherdtomakeonelasteffort.Theyoungstersareexhaustedbuttheirmothershavemadethisjourneybeforeandtheyknowthatthey'reclosetowater.Aftermanyhundredsofmilesthey'vearrived.Thelivesoftheseelephantsaredominatedbytheannualrhythmofwetanddry,aseasonalcyclecreatedbythesun.Atthesouthernendoftheearth,afterfourmonthsoftotaldarkness,thesunoncemorerisesoverAntarctica.NowatlasttheEmperorpenguinsabandontheirhuddle.Themalesarestillcarryingthepreciouseggsthatthey'vecherishedthroughouttheAntarcticwinter.Withthereturningsuntheeggshatch.Otherbirdshavenotevenarrived.buttheEmperorsbyenduringthelongblackwinterhavegiventheirchicksaheadstart.TheseyoungstersarenowreadyandeagertomakethemostofthebriefAntarcticsummer.第2集PLANETEARTHMountainsHumanbeingsventureintothehighestpartsofourplanetattheirperil.Somemightthinkthatbyclimbingagreatmountaintheyhavesomehowconqueredit,butwecanonlybevisitorshere.Thisisafrozenalienworld.Thisistheotherextreme-oneofthelowesthottestplacesonEarth.It'soverahundredmetresbelowthelevelofthesea.Buthereamountainisingestation.Poolsofsulphuricacidareindicationsthatdeepundergroundtherearetitanicstirrings.ThisistheDanakilDepressioninEthiopia,lyingwithinacolossalrentoftheearth'ssurfacewheregiantlandmassesarepullingawayfromoneanother.Lavarisestothesurfacethroughthiscrackinthecrustcreatingachainofyoungvolcanoes.Thisone,ErtaAle,istodaythelongestcontinuallyeruptingvolcanoontheplanet,alakeoflavathathasbeenmoltenforoverahundredyears.ThesesamevolcanicforcesalsocreatedEthiopia'shighlands.70millionyearsagothislandwasjustasflatandasdeepastheDanakilDepression.Moltenlavarisingfromtheearth'scoreforcedupahugedomeofrock500mileswide,theroofofAfrica.Overmillennia,rainandicecarvedtherockintoalandscapeofspiresandcanyons.Thesesummits,nearly3milesup,arehometosomeveryremarkablemountaineersGeladababoons.TheyareuniquetothehighlandsofEthiopia.Thecliffswheretheysleepareforexpertclimbersonly,andGeladocertainlyhavetherightequipment.thestrongestfingersofanyprimateandanutterlyfearlessdisposition.Butyouneedmorethanaheadforheightstosurviveuphere.AdayinaGelado'sliferevealshowthey'verisentothechallenge.Forallmonkeysmorningisgroomingtime,achancetocatchupwithfriends.But,unlikeothermonkeys,Geladoschatterconstantlywhiletheydoit.It'sagreatwaytonetworkwhileyourhandsarebusy.Butthesesocialscan'tgoonfortoolong.Geladoshaveabusydailyscheduleandthere'sworktobedone.Mostmonkeyscouldn'tliveuphere.There'snofoodandfewinsectstofeedon.ButGeladosareuniquethey'retheonlymonkeysintheworldthatlivealmostentirelyongrass.Theyliveinthelargestassembliesformedbyanymonkeys.Somegroupsare800strongandtheycropthehighmeadowslikeherdsofwildebeest.TheGeladosgrazealongsideWaliaibex,whicharealsouniquetothesehighlands.TheserarecreaturesareusuallyveryshybuttheydroptheirguardwhentheGeladosarearound.Youmightexpectthatgrazerswouldavoideachother'spatchbutthisisaspecialalliancefromwhichbothpartnersbenefit.It'snotsoriskytoputyourheaddownifothersareonthelookout.Ethiopianwolves-theywon'tattemptanattackinbroaddaylight.Butatdusktheplateaubecomesamoredangerousplace.Withthegrazinglargelyoverthere'salastchancetosocialisebeforereturningtothesleepingcliffs.Anearlywarningsystemputseveryoneonthealert.Theirdayendsasitbegan,safeonthesteepcliffs.TheEthiopianvolcanoesaredormant,butelsewhereothersstillrage.Volcanoesformthebackboneofthelongestmountainchainonourplanet-theAndesofSouthAmerica.Thisvastrangestretches5,000milesfromtheEquatordowntotheAntarctic.ItformedasthefloorofthePacificOceanslidbeneaththeSouthAmericancontinent,bucklingitsedge.AtthesouthernendstandthemountainsofPatagonia.It'shighsummer,buttheAndeshavethemostunstablemountainweatherontheplanetandstormscaneruptwithoutwarning.Temperaturesplummetandguanacosandtheirnewbornyoungmustsuddenlyendureablizzard.Truly,allseasonsinoneday...Apuma-thelionoftheAndes.Pumasareusuallysolitaryandsecretive.Toseeagroupwalkingboldlyintheopenisextremelyrare.It'safamily-amotherwithfourcubs.Shehasjustonebriefsummerinwhichtoteachthemtheirmountainsurvivaltechniques.Rearingfourcubstothisageisanexceptionalfeat,butshedoeshaveanexcellentterritory,richinfoodandwater.Althoughthecubsarenowaslargeastheirmother,theystillrelyonherfortheirfood.Itwillbeanotheryearbeforethecubscanhuntforthemselves.Withouttheirmother'sskillandexperiencetheywouldneversurvivetheirfirstwinter.Batteredbyhurricaneforcewinds,theseslopesarenowlifeless.Furthernorth,theyholdotherdangers.Movingat250milesanhour,anavalanchedestroyseverythinginitspath.IntheAmericanRockiesa100,000avalanchesdevastatetheslopeseverywinter.ThishugemountainchaincontinuesthegreatspinethatrunsfromPatagoniatoAlaska.TheslopesoftheRockies,bleakthoughtheyare,provideawinterrefugeforsomeanimals.Amothergrizzlyemergesfromherdenaftersixmonths'dozingunderground.Hertwocubsfollowherandtaketheirfirststepsintheoutsideworld.Thesesteepslopesprovideasanctuaryforthecubs.Amalebearwouldkillandeatthemgiventhechance.Butbiganimalsfinditdifficulttogetabouthere.Malesmaybetwicethesizeofafemaleandevenshecanhaveproblems.Hercubs,however,makelightofthesnowandoflifeingeneral.Butthemotherfacesadilemma:it'ssixmonthssinceshelastfedandhermilkisstartingtorundry.Shemustsoonleavethesafetyofthesenurseryslopesandleadhercubsawayfromthemountain.Ifshedelays,thewholefamilywillriskstarvation.SummerrevealsthetruenatureoftheRockies.Strippedofsnow,thepeaksbeartheirsculptedforms.Onlynowcanmountaineersreclaimtheupperreaches.Twomilesupthecrumblingprecipicesseemdevoidoflife.Butthereareanimalshere-agrizzlybear.Itseemstobeanoddcreaturetofindonthesehighrockyslopes.It'shardtoimaginewhatcouldhaveattractedithere.Atthistimeoftheyearbearsshouldbefatteningupforthewinter.Yettheygatherinsomenumbersontheseapparentlybarrenslopes.They'researchingforaratherunusualfood-moths.Millionshaveflownupheretoescapetheheatofthelowlandsandthey'renowroostingamongtherocks.Mothsmayseemameagermealforabear,buttheirbodiesarerichinfatandcanmakeallthedifferenceinabear'sannualstruggleforsurvival.Anotherbattleisbeingwagedherebutonamuchlongertimescale.Theseloosebouldersarethemountain'scrumblingbones.TheRockiesarenolongerrisingbutslowlydisintegrating.Allmountainseverywherearebeingworndownbyfrost,snowandice.TheAlpswereraisedsome15millionyearsagoasAfrica,driftingnorthwards,collidedwiththesouthernedgeofEurope.Thesespiresaretheerodedremainsofanancientseabedthatoncestretchedbetweenthetwocontinents.ButthesearejusttheAlpinefoothills.Therangeatitscentrerisesto3mileshighandiscrownedwithpermanentsnows.TheMatterhorn,itssummittoosteeptoholdasnowfield.MontBlanc-thehighestpeakinWesternEurope.ThedistinctivejaggedshapesoftheAlpswerecarvedbythosegreatmountainsculptors-theglaciers.Immenseriversofmovingice,ladenwithrock,grindtheirwaydownthemountains,gougingoutdeepvalleys.They'rethemostpowerfulerosiveforceonourplanet.Amoulin-ashaftintheiceopenedbymeltwaterasitplungesintothedepthsoftheglacier.Likethewaterrunningthroughit,theiceitselfisconstantlymoving,flowingdownthevalleywithunstoppableforce.Alpineglaciersmayseemimmense,butthey'redwarfedbythoseinthegreatrangesthatdividetheIndiansubcontinentfromTibet.ThisistheboulderstrewnsnoutofthegiantBaltoroglacierintheKarakorammountainsofPakistan.It'sthebiggestmountainglacieronEarth-43mileslongandover3mileswide.Thishugeice-filledvalleyissolargeit'sclearlyvisiblefromspace.Thisisthegreatestconcentrationofpeaksover5mileshightobefoundanywhereonEarth.They'rethemostdangerousmountainsofall.K2andhersisterpeakshaveclaimedmorelivesthananyothers.Thepeakshererisesoprecipitously,theglaciersaresosteepandcrevassedthatfewexceptthemostskilledmountaineerscanpenetratetheseranges.Markhorgatherfortheirannualrut.Malesmustfightfortherighttobreed,butonthesesheercliffsanyslipbyeitheranimalcouldbefatal.Asnowleopard-therarestofHimalayananimals.It'safemalereturningtoherlair.Thesearethefirstintimateimagesofsnowleopardeverfilmedinthewild.Shegreetsheroneyearoldcub.Herdeniswellchosen.Ithasexceptionalviewsofthesurroundingcliffs.Onthesetreacherousslopesnohunterotherthanthesnowleopardwouldhaveachanceofcatchingsuchfragileprey.Afemalewithyoungmakesaneasiertarget.Herlargepawsgiveanexcellentgr