大熊猫的现状濒危原因及其保护对策ResearchGate.docx
- 文档编号:24091353
- 上传时间:2023-05-24
- 格式:DOCX
- 页数:12
- 大小:196.40KB
大熊猫的现状濒危原因及其保护对策ResearchGate.docx
《大熊猫的现状濒危原因及其保护对策ResearchGate.docx》由会员分享,可在线阅读,更多相关《大熊猫的现状濒危原因及其保护对策ResearchGate.docx(12页珍藏版)》请在冰豆网上搜索。
大熊猫的现状濒危原因及其保护对策ResearchGate
Statusandconservationofgiantpanda(Ailuropodamelanoleuca):
areview
JianjunPENG1,ZhigangJIANG1*andJinchuHU2
1InstituteofZoology,ChineseAcademyofSciences,Beijing,100080,China;
e-mail:
jiangzg@orjjpeng74@
2SichuanTeachersCollege,SichuanProvince,637002,China
Received28February2001;Accepted29March2001
Abstract.ThegiantpandawasoncewidelydistributedinChina,partsofBurma,Vietnam,andThailand.Fossilsofthegiantpandaanditsrelativeshavebeenfoundatmorethan40sitesin16provincesofChinaandalsoinnorthofVietnam.Withtherapidincreaseofhumanpopulations,theexpansionofagricultureandlarge-scaledeforestation,thehabitatofthegiantpandahasbeengreatlyreduced.Atpresent,only12,000km2ofhabitat,about1/5oftherangeofgiantpanda40yearsago,remainsinSichuan,ShaanxiandGangsuProvinces.Thenumberofgiantpandasinthefieldwasestimatedtoabout1000.Breedinggiantpandasincaptivityisverydifficult.Morethan10countriesintheworldobtained42wildgiantpandasfromChinabetween1936~1999,thosepandasbredin14zoos,butonlysixofthemsurviveatfivezoosinfourcountries.Unluckily,only12malesand21femalesreproducedbetween1936~1998.Twohundredandtwenty-sixcubswereborninzoosandconservationbreedingcentersthroughouttheworldduring1963~1998,but109diedwithin30daysofbirth.Nomorethan30%ofthosecubssurvivedformorethanthreeyearsincaptivity.Weanalyzedthreatstothegiantpandasuchaspoaching,habitatdestructionanddegradation,lowreproductiveability,diseases,naturalenemies,bamboofloweringandinbreeding.Wealsodiscussconservationissuessuchas:
habitatconservation,exsituconservationandthefieldreleaseofcaptive-bredgiantpandas.
Keywords:
giantpanda(Ailuropodamelanoleuca),status,conservation,China
Introduction
AlthoughthegiantpandaisonlydistributedinChina,itisthenaturallegacyofpeopleallovertheworld.However,thegiantpandaisonthevergeofextinction,andonlysurvivesinsmallpatchesofhabitatover12,000km2(Hu1997).TheChinesegovernmenthasestablishedtwenty-fournaturereservestopreservegiantpandas(Li&Zhou1999),however,expandinghumanpopulationandnationaleconomyhaveactedtoreducethehabitatofthegiantpanda.Inthispaper,wereviewthestatusandconservationofthegiantpanda.
HistoricalandPresentDistribution
ThegiantpandawasoncewidelydistributedthroughoutChina,partsofBurma,VietnamandThailand.Fossilsofthegiantpandaanditsrelativeshavebeenfoundatmorethan40sitesin16provincesofChina(Fig.1),andmanylocalchroniclesalsorecordedtheirdistributioninChina(Hu1997,Tougardetal.1996,Maetal.1994,Zhu&Long1983,Feng1991a).Withtherapidincreaseinhumanpopulationandthespeedingupofdeforestation,thehabitatofthegiantpandahasbeencontinuallyreduced.Nowthegiantpandaonlysurvivesinsixsmallareas-theQinling,Minshan,Qionglai,BigXiangling,SmallXianglingandLiangshanMountains(Hu1985a,b,1993a,b,1997).
Fig.1.Historicalrecord,fossillocalitiesandpresentdistributionofthegiantpanda.
Thehumanpopulationincreasedtomorethan0.43millionwithinthehabitatsofthegiantpandainSichuan,ShaanxiandGansuprovincesfrom1950sto1990s.Thenumberoflargeloggingcorporationsincreasedto27from1950~1985(notincludingsmallloggingfactories).Thesedeforested42256km2forestsuntilthegovernmentdecidedtostoptheloggingofnaturalforestsinthecountryin1999.Thehabitatofthegiantpandawasestimatedtobe12000km2(Fig.2),only1/5ofthatof40yearsago,andthenumberofcountiesinhabitedbythegiantpandadecreasedfrom48to38(Hu1993a,b,1997,Fengetal.1991a).
Fig.2.Habitatlossinthegiantpanda’ssixmountainhabitatareas.
PopulationSize
Populationdecreasesinthefield
Twosurveysoffieldpopulationsofthegiantpandawerecarriedoutinthe1970sand1980s,respectively.Theoutcomeshowedthatthegiantpandapopulationhaddecreasedrapidlyinthefield(Fig.3).Uptothe1990s,thepopulationsizedecreasedtoabout1000(Hu1997),withabout200giantpandasremainingintheQinlingmountains,about350intheMinshanmountains,butnomorethan50intheGreaterandSmallerXianglingmountains,andnomorethan100intheLiangshanmountains.
Captivepopulation
Accordingtohistoricalrecords,thegiantpandawasbredincaptivityinancienttimes(Hu1989,1997).ModernzoosdidnotstarttobreedthegiantpandauntilNovember1936.ChicagoZoobredthefirstmalegiantpandabroughtfromWenchuan,Sichuan.Uptotheendof1998,onehundredandseventeengiantpandas(51malesand66females)stillsurvivedincaptivity(Xie&Gipps1999).From1936~1999,morethan10countries,suchastheUnitedStates,GreatBritain,France,Russia,NorthKorea,SouthKorea,Germany,Spain,MexicoandJapan,obtained42wildborngiantpandasfromChina,thosepandasbredin14zoos,butonlysixofthemnowsurviveatfivezoosinfourcountries(Hu1997,Xie&Gipps1999).Moreover,thefirstrecordsofcaptive-bredgiantpandasinChinawereatBeibeiPark,ChongqingandZhaofengPark(nowZhongshanPark),Shanghaiin1939.Upto1999,morethan220wildgiantpandaswerebredinforty-fivezoosandnaturereservesinChina,butonly42ofthosepandassurviveintwentyzoosandnaturereservesnow(Hu1997,Xie&Gipps1999).
Fig.3.Decreasesinthenumbersofgiantpandasinthewildinvariousdistrictsandcounties.
ReproductivePerformanceinCaptivity
Itisdifficulttobreedthegiantpandaincaptivityduetotheirlatesexualmaturity,lowreproductiverateandhighcubmortality(Pengetal.2001).Incaptivity,theageofsexualmaturityoffemalegiantpandasisgenerally5.5~6.5years,and6.5~7.5yearsforthemale(Hu1988,Wang1990).Accordingtothe1997InternationalStudbookforGiantPanda(Xieetal.1997),41malesand46femalesincaptivityreachedsexualmaturity,butonly12malesand21femalesbred(Huangetal.1999).Inparticular,thenumberofsexuallyactivemaleswaslessthanthatofsexuallyactivefemalesincaptivity.Moreover,226cubswereborninzoosandconservationbreedingcentersallovertheworldbetween1963~1998.However,109diedwithin30daysofbirth,sothatthedeathratewas48%(Xie&Gipps1999,Pengetal.2001).Lessthan30%ofthosecubssurvivedformorethanthreeyears(Fengetal.1997,Huang1994,Lietal.1999,Xie&Gipps1999).
ThreatstotheGiantPanda
Captureandpoaching
Theimmediatefactorthatresultedinrapidpopulationdeclineofthegiantpandawascaptureandhuntingbypeople.Morethan20giantpandasinWenchuancounty,Sichuanwerehuntedduring1930s(Hu1993a,b).ThelargestscalecaptureofgiantpandastookplaceinNovemberin1945,whenmorethantwohundredpeopleweredividedintotengroupstocapturegiantpandasinthefield(Hu1993a,b).Fromthe1950stothepresentday,morethantwohundredandfortywildgiantpandashavebeencapturedandheldforbreedinginzoosthroughouttheworld.Morethan110ofthosepandascamefromBaoxingCountyandmorethan60camefromPingwuCounty.Consequently,thegiantpandapopulationsinthesetwocountieshavebeendestroyedandthegiantpandapopulationhasdecreasedgreatly.Somepoachersevenoperateinnaturereserves.Forexample,twofemalegiantpandaswerekilledinsnaresintheWolongNaturalReservein1983-onepandawaswearingaradiocollar(Hu1985b,1993a,b,1997).
Habitatlossanddegradation
GiantpandainhabitChina’sethnicminorityregionswhereslash-and-burncultivationisstillwidelypracticed.Inthe20thcentury,forestedhillsandmountainshavebeenturnedintofarmlandsandsettlementssothatthegiantpandalostitsforagingbaseatloweraltitudes(Hu1985b,Pan&Gao1988).Decreasesinforestarearesultedinhabitatlossforthegiantpanda.Pandaswereisolatedinhabitatremnants,somewiththree~fivegiantpandas(Hu1997,Fengetal.1991a,b).Smallpopulationsizewouldacceleratethelossofgeneticvariationduetoinbreeding,whichcoulddecreasethefitnessofindividualsandthepopulationandmightevenresultinpopulationextinction(Shaffer1981,Hu1985b).
Bambooflowering
Thepatternofbamboofloweringhasresultedinfoodshortagesforthegiantpanda.Becausethebehaviouranddietofthegiantpandaishighlyspecialized,oncethebamboohasflowered,pandasmaystarvetodeath.Theperiodicityofbamboofloweringisabout40~120years(Janzen1976).Severalspeciesofbamboogrewwithintherangeofthegiantpanda,andgenerallyoneormorebamboospeciesbloomscoveringeitherasmallareaorthewholehillsideorvalley.Forexample,severalFargesiaspp.bloomedinMinshanmountaininthe1970sand1980sand,consequently,manygiantpandasdiedduetoshortageoffood:
138deadpandaswerefoundinthefield.Likewise,SinarundinariafangianaandFargesiaspathaceaintheQionglaiandQinlingmountainsbloomedfrom1983(Pan&Gao1988)to1994,withonehundredandforty-onegiantpandasdying(Hu1993a,b,1997).
Lowreproductiverate
Fengetal.(1983,1984a,b,c,1991b)dissectedsixfemalegiantpandasthatdiedduringtheperiodofoestrousandobservedtheirovarianstructure.Theyfound400~500near-matureovarianfolliclesprojectingfromtheovariansurfaceandclumpedintopiles-ararephenomenonincarnivores.However,theinteractionbetweenovaryandfolliclesmightaffectthematurationoftheovules,sothefemalecouldnotovulateonebyone(Fengetal.1991b).Thepanda’sgestationperiodisshortandfertilized-eggimplantat
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 大熊猫 现状 濒危 原因 及其 保护 对策 ResearchGate