动物保护类文章结构讲义.pdf

1、本文档共17页，可阅读全部内容。
2、原创力文档（book118）网站文档一经付费（服务费），不意味着购买了该文档的版权，仅供个人/单位学习、研究之用，不得用于商业用途，未经授权，严禁复制、发行、汇编、翻译或者网络传播等，侵权必究。
3、本站所有内容均由合作方或网友上传，本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺！文档内容仅供研究参考，付费前请自行鉴别。如您付费，意味着您自己接受本站规则且自行承担风险，本站不退款、不进行额外附加服务；查看《如何避免下载的几个坑》。如果您已付费下载过本站文档，您可以点击这里二次下载。
4、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等，请点击“版权申诉”（推荐），也可以打举报电话：400-050-0827(电话支持时间：9:00-18:30)。

WildlifeProtection

Afteryearsofheateddebate,graywolveswerereintroducedtoYellowstoneNationalPark.Fourteenwolves

werecaughtinCanadaandtransportedtothepark.Bylastyear,theYellowstonewolfpopulationhadgrowntomore

than170wolves.

GraywolvesoncewereseenhereandthereintheYellowstoneareaandmuchofthecontinentalUnitedStates,

buttheyweregraduallydisplacedbyhumandevelopment.Bythe1920s,wolveshadpracticallydisappearedfrom

theYellowstonearea.TheywentfarthernorthintothedeepforestsofCanada,wheretherewerefewerhumans

around.

Thedisappearanceofthewolveshadmanyunexpectedresults.Deerandelkpopulations—majorfoodsources

(来源)forthewolf–grewrapidly.Theseanimalsconsumedlargeamountsofvegetation(植被),whichreduced

plantdiversityinthepark.Intheabsenceofwolves,coyotepopulationsalsogrewquickly.Thecoyoteskilledalarge

percentageofthepark’sredfoxes,andcompletelydroveawaythepark’sbeavers.

Asearlyas1966,biologistsaskedthegovernmenttoconsiderreintroducingwolvestoYellowstonePark.They

hopedthatwolveswouldbeabletocontroltheelkandcoyoteproblems.Manyfarmersopposedtheplanbecause

theyfearedthatwolveswouldkilltheirfarmanimalsorpets.

Thegovernmentspentnearly30yearscomingupwithaplantoreintroducethewolves.TheU.S.Fishand

WildlifeServicecarefullymonitorsandmanagesthewolfpacksinYellowstone.Today,thedebatecontinuesover

howwellthegraywolfisfittinginatYellowstone.Elk,deer,andcoyotepopulationsaredown,whilebeaversand

redfoxeshavemadeacomeback.TheYellowstonewolfprojecthasbeenavaluableexperimenttohelpbiologists

decidewhethertoreintroducewolvestootherpartsofthecountryaswell.

28.Whatisthetextmainlyabout?

A.WildliferesearchintheUnitedStates

该用户很懒，什么也没介绍

咨询Ta 进入空间

更多 >