2019職稱英語理工A類閱讀理解題精講7

2019職稱英語理工A類閱讀理解題精講7AntsHaveBigImpactonEnvironmentas"EcosystemEngineers"ResearchbytheUniversityofExeter1hasrevealedthatantshaveabigimpactontheirlocalenvironmentasaresultoftheiractivityas"ecosystemengineers"andpredators.Thestudy,publishedintheJournalofAnimalEcology,foundthatantshavetwodistincteffectsontheirlocalenvironment.Firstly,throughmovingofsoilbynestbuilding2activityandbycollectingfoodtheyaffectthelevelofnutrientsinthesoil.Thiscanindirectlyimpactthelocalpopulationsofmanyanimalgroups,fromdecomposerstospeciesmuchhigherupthefoodchain.Secondly,theypreyonawiderangeofotheranimals,includinglargerpreywhichcanbeattackedbyvastnumbersofantworkers.DirkSanders,anauthorofthestudyfromtheuniversity'sCentreforEcologyandConservation,said："Antsareveryeffectivepredatorswhichthriveinhugenumbers.They'realsoveryterritorial3andveryaggressive,defendingtheirresourcesandterritoryagainstotherpredators.Allofthismeanstheyhaveastronginfluenceontheirsurroundingarea.""Inthisresearch,westudiedforthefirsttimehowbigthisimpactisandthesubtletiesofit.Whatwefoundisthatdespitebeingpredators,theirpresencecanalsoleadtoanincreaseindensityanddiversityofotheranimalgroups4.Theygenuinelyplayakeyroleinthelocalenvironment,havingabiginfluenceonthegrasslandfoodweb,"Sanderssaid.Thestudy,carriedoutinGermany,studiedtheimpactofthepresenceofdifferentcombinationsanddensitiesofblackgardenantsandcommonredants,bothspecieswhichcanbefoundacrossEurope,includingintheUK.Itfoundthatalowdensityofantsinanareaincreasedthediversityanddensityofotheranimalsinthelocalarea,particularlythedensityofherbivoresanddecomposers.Athigherdensitiesantshadnoortheoppositeeffect,showingthatpredationiscounteractingthepositiveinfluence.DrFrankvanVeen,anotherauthoronthestudy,said"Whatwefindisthattheimpactofantsonsoilnutrientlevelshasapositiveeffectonanimalgroupsatlowlevels,butasthenumberofantsincreases,theirpredatoryimpactshavethebiggereffect—therebycounteractingthepositive

：influenceviaecosystemengineering."Antsareimportantcomponentsofecosystemsnotonlybecausetheyconstituteagreatpartoftheanimalbiomass5butalsobecausetheyactasecosystemengineers.Antbiodiversity6isincrediblyhighandtheseorganismsarehighlyresponsivetohumanimpact,whichobviouslyreducesitsrichness.However,itisnotclearhowsuchdisturbancedamagesthemaintenanceofantservicestotheecosystem.Antsareimportantinbelowgroundprocesses8throughthealterationofthephysicalandchemicalenvironmentandthroughtheireffectsonplants,microorganisms,andothersoilorganisms.詞匯：predator/'predt/n.食肉動物nutrient/'nju：trint/n.營養(yǎng)物;adj.營養(yǎng)的decomposer/,di：km'puz/n.腐生物;分解體prey/prei/v.捕食;n.被捕食的動物subtlety/'stlti/n，奇妙，精妙herbivore/'h：biv：/n.食草動物說明：1.theUniversityofExeter：埃克斯特大學(xué)。1851年建校，位于英國西南部重要商業(yè)中心?？怂固厥?，是英國的傳統(tǒng)大學(xué)之一。2.nestbuilding：筑巢3.territorial：領(lǐng)地的。在此用來形容螞蟻的天性，即擁有很強(qiáng)的領(lǐng)地意識，而且會全力以赴捍衛(wèi)自己的領(lǐng)地。anincreaseindensityanddiversityofotheranimalgroups：其余動物集體在數(shù)目和品種上的增加。biomass：物質(zhì)名詞，由bio和mass兩部分構(gòu)成，意為“生物量”“生物質(zhì)”。