DEERANDTHEENERGYCYCLE能源.docx
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DEERANDTHEENERGYCYCLE能源.docx
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DEERANDTHEENERGYCYCLE能源
Isthereanythingwecanlearnfromdeer?
Duringthe"energycrisis"of1973-1974thewriterofthisessaywaslivinginnorthernMinnesotaandwasabletoobservehowdeersurvivewhenwinterarrives.Thelessonshelearnsabouthewaydeerconserveenergyturnoutapplicabletooureverydaylife.
DEERANDTHEENERGYCYCLE
Somepersonssaythatlovemakestheworldgoround.Othersofalessromanticandmorepracticalturnofmindsaythatitisn'tlove;it'smoney.Butthetruthisthatitisenergythatmakestheworldgoround.Energyisthecurrencyoftheecologicalsystemandlifebecomespossibleonlywhenfoodisconvertedintoenergy,whichinturnisusedtoseekmorefoodtogrow,toreproduceandtosurvive.Onthiscyclealllifedepends.
Itisfairlywellknownthatwildanimalssurvivefromyeartoyearbyeatingasmuchastheycanduringtimesofplenty,thesummerandfall,storingtheexcess,usuallyintheformoffat,andthenusingthesereservesoffattosurviveduringthehardtimesinwinterwhenfoodisscarce.Butitisprobablylesswellknownthatevenwiththeirstoredfat,wildanimalsspendlessenergytoliveinwinterthaninsummer.
Agoodcaseinpointisthewhiter-taileddeer.Likemostwildlife,deerreproduce,grow,andstorefatinthesummerandfallwhenthereisplentyofnutritiousfoodavailable.AphysicallymaturefemaledeeringoodconditionwhohasconceivedinNovemberandgivenbirthtotwofawnsduringtheendofMayorfirstpartofJune,mustsearchforfoodforthenecessaryenergynotonlytomeetherbody'sneedsbutalsotoproducemilkforherfawns.Thebestmilkproductionoccursatthesametimethatnewplantgrowthisavailable.Thisisgoodtiming,becausemilkproductionisanenergyconsumingprocess—itrequiresalotoffood.Thecostcannotbemetunlesstheregionhasamplefoodresources.
Asthesummerprogressesandthefawnsgrow,theybecomelessdependentontheirmother'smilkandmoredependentongrowingplantsasfoodsources.Theadultmalesspendthesummergrowingantlersandgettingfat.Bothmalesandfemalescontinuetoeathighqualityfoodinthefallinordertodepositbodyfatforthewinter.Inthecaseofdoesandfawns,agreatdealofenergyisexpendedeitherinmilkproductionoringrowing,andfatisnotaccumulatedasquicklyasitisinfullgrownmales.Fatreservesarelikebankaccountstobedrawnoninthewinterwhenfoodsuppliesarelimitedandsometimesdifficulttoreachbecauseofdeepsnow.
Asfallturnsintowinter,otherchangestakeplace.Fawnslosetheirspottedcoat.Haironallthedeerbecomesdarkerandthicker.ThechangeinthehaircoatsisusuallycompletebySeptemberandmaximumhairdepthsarereachedbyNovemberorDecemberwhentheweatherbecomescold.
Butinaddition,natureprovidesafurthersafeguardtohelpdeersurvivethewinter—aninternalphysiologicalresponsewhichlowerstheirmetabolism,orrateofbodilyfunctioning,andhenceslowsdowntheirexpenditureofenergy.Thedeerbecomesomewhatslowanddrowsy.Theheartratedrops.Animalsthathibernatepracticeenergyconservationtoagreaterextremethandeerdo.Althoughdeerdon'thibernate,theydothesamethingwiththeirseasonalrhythmsinmetabolism.Deerspendmoreenergyandstorefatinthesummerandfallwhenfoodisabundant,andspendlessenergyandusestoredfatinthewinterwhenfoodislessavailable.
Whenthe"energycrisis"firstcamein1973-1974,IwaslivingwithmyfamilyinacabinontheedgeofanareawheredeerspendthewinterinnorthernMinnesota,observingthedeerastheirbehaviorchangedfrommoreactivityinsummerandfalltolessaswinterprogressed,followedbyanincreaseagaininthespringasthesnowmelted.Itwasinterestingandratheramusingtolistentotheadvicegivenontheradio:
"Driveonlywhennecessary,"weweretold."Putonmoreclothestostaywarm,andturnthethermostatonyourfurnacedown."Meanwhilewewatchedthedeerreducetheiractivity,growawintercoatofhair,andreducetheirmetabolismastheyhaveforthousandsofyears.Itisbiologicallyreasonablefordeertoreducetheircostoflivingtoincreasetheirchanceofsurvivinginwinter.
Noteverywinteriscriticalfordeerofcourse.Ifthewinterhaslightsnow,survivalandproductivitynextspringwillbehigh.Butifdeepsnowscomeandtheweatherremainscoldforseveralweeks,thenthedeermustspendmoreenergytomoveabout,foodwillbehardertofind,andtheymustthendependmoreontheirfatreservestopullthemthrough.Ifsuchconditionsgoonfortoolongsomewilldie,andonlythelargestandstrongestarelikelytosurvive.Thatisafundamentalruleoflifeforwild,freewanderinganimalsuchasdeer.
Yes,life—anddeath,too--isacyclethatgoesroundandround,andwhenanimalsdietheirbodiesbecomefoodforotherlifeformstousebyconvertingthemintoenergy.
Andthecyclecontinues.
NewWords
Deer
n. (sing.orpl.)鹿
romantic
a. belongingtoorsuggestingromance;fancifulnotpractical浪漫的;幻想的
turn
n. anaturaltendency;inclination(天生)倾向
currency
n. moneythatisactuallyinuseinacountry通货,货币
ecological
a. oforconcerninginterrelationshipoforganismsandtheirenvironment生态的
ecology
n. 生态学
convert
vt.change(fromoneform,use,etc.intoanother);cause(aperson)tochangehisbeliefs,etc.使转变;使改变信仰(等)
excess
n. thepartthatismorethanenough;theconditionofexceedingwhatisusualornecessary过量;过度
reserve
n. sth.thatisbeingorhasbeenstoredforlateruse储备(物)
scarcea. notavailableinsufficientquantity缺乏的
wildlife
n. animalsandplantswhichliveandgrowwild
nutritious
a. fullgrownanddeveloped成熟的;成年的
female
a. ofthesexthatgivesbirthtoyoung 女(性)的;雌的
n. afemaleperson,animalorplant
conceive
vt.becomepregnantwith(young);form(anidea,plan,etc.)inthemind怀(胎);构思
fawn
n. ayoungdeerlessthanayearold
timing
n. selectionformaximumeffectoftheprecisemomentforbeginningordoingsth.时机的选择
consume
vt.eatordrink;use;useup消耗;消费
region
n. aplace,spaceorarea;apartofthebody地区;(身体的)部位
ample
a. plentiful充裕的
resource
n. (pl.)possessions(esp.ofacountry).intheformofwealthandgoods,thathelponetodowhatonewants资源
dependent
a.relying(onanother)forsupport
male
a. ofthesexthatdoesnotgivebirthtoyoung男(性)的;雄的
n. amaleperson,animalorplant
antler
n. thesolid,bonyhornofamaledeer鹿角,茸角
deposit
vt.putorstoreforsafekeeping;(esp.ofaliquid,ariver)leavelying(alayerofmatter)存放;使沉积
doe
n. afully-grownfemaledeer
expend
vt.spendoruseup花费;耗尽
accumulate
v. makeorbecomegreaterinnumberorquantity;collectorgather积累;积聚
account
n. asumofmoneykeptinabankwhichmaybeaddedtoortakenfrom帐户;存款
spotted
a. markedwithspots
depth
n. thestateordegreeofbeingdeep深;深度,厚度
safeguard
n. ameansofprotectionagainststh.unwanted预防措施
internal
a. oforintheinside,esp.ofthebody内部的;体内的
physiological
a. 生理的;生理学的
metabolism
n. 新陈代谢
hence
ad.therefore因此,所以
expenditure
n. expendingorusingup;theamountofmoney,time,etc.expended花费;用光;支出额,费用
somewhat
ad.bysomedegreeoramount;alittle有点,稍微
drowsy
a. sleepyorhalfsleepy;makingonesleepy困倦的;催眠的
hibernate
vi.(ofsomeanimals)passthewholeofthewinterinastatelikesleep冬眠
extreme
n. eitherendofanything;highestdegree极端
seasonal
a. dependingontheseason;changingwiththeseasons季节性的
rhythm
n. 节奏
abundant
a. morethanenough充足的;丰富的
cabin
n. asmallroughlybuilt,usu.woodenhouse小木屋;茅舍
melt
v. cause(asolid)tobecomeliquid;(ofasolid)becomeliquid(使)融化;(使)熔化
amusing
a. funny逗人笑的;引起乐趣的
amuse
vt.causetolaughorsmile
thermostat
n. anautomaticdeviceforregulatingtemperature恒温器
biologically
ad.生物学上
biological a.
survival
n. thefactorlikelihoodofsurviving幸存
productivity
n. theabilityorcapacitytoproduce,productiveness生产力;生产率;多产
fundamental
a. basic;mostimportant
Phrases&Expressions
goround
functionsmoothly
intheformof
以…形式
inpoint
appropriate;pertinent适用的;相关的
in(good)condition
ingoodhealth,physicallyfit
givebirth(to)
bear;(fig.)produce生(孩)子,产(仔);产生,引起
drawon
takeoruseasasource利用;动用
slowdown
(causeto)gomoreslowlythanusual;(causeto)live,work,etc.inalessactiveandintenseway(使)慢下来;(使)放松
turndown
reducetheforce,speed,loudness,etc.of(sth.)byusingcontrols减弱;关小,调低
moveabout
travelaround;gofromoneplacetoanother
pullthrough
help(sb.)tosurviveaperiodofdangerorcrisis使渡过危险或危机
ProperName
Minnesota
明尼苏达(美国州名)
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