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1、AntsHaveBigImpactonEnvironmentas"EcosystemEngineers"ResearchbytheUniversityofExeter1hasrevealedthatantshaveabigimpactontheirlocalenvironmentasaresultoftheiractivityas"ecosystemengineers"andpredators.Thestudy,publishedintheJournalofAnimalEcology,foundthatantshavetwodistincteffe
2、ctsontheirlocalenvironment.Firstly,throughmovingofsoilbynestbuilding2activityandbycollectingfoodtheyaffectthelevelofnutrientsinthesoil.Thiscanindirectlyimpactthelocalpopulationsofmanyanimalgroups,fromdecomposerstospeciesmuchhigherupthefoodchain.Secondly,theypreyonawiderangeofo
3、theranimals,includinglargerpreywhichcanbeattackedbyvastnumbersofantworkers.DirkSanders,anauthorofthestudyfromtheuniversity'sCentreforEcologyandConservation,said:"Antsareveryeffectivepredatorswhichthriveinhugenumbers.They'realsoveryterritorial3andveryaggressive,defendingtheirre
4、sourcesandterritoryagainstotherpredators.Allofthismeanstheyhaveastronginfluenceontheirsurroundingarea.""Inthisresearch,westudiedforthefirsttimehowbigthisimpactisandthesubtletiesofit.Whatwefoundisthatdespitebeingpredators,theirpresencecanalsoleadtoanincreaseindensityanddiversit
5、yofotheranimalgroups4.Theygenuinelyplayakeyroleinthelocalenvironment,havingabiginfluenceonthegrasslandfoodweb,"Sanderssaid.Thestudy,carriedoutinGermany,studiedtheimpactofthepresenceofdifferentcombinationsanddensitiesofblackgardenantsandcommonredants,bothspecieswhichcanbefounda
6、crossEurope,includingintheUK.Itfoundthatalowdensityofantsinanareaincreasedthediversityanddensityofotheranimalsinthelocalarea,particularlythedensityofherbivoresanddecomposers.Athigherdensitiesantshadnoortheoppositeeffect,showingthatpredationiscounteractingthepositiveinfluence.D
7、rFrankvanVeen,anotherauthoronthestudy,said:"Whatwefindisthattheimpactofantsonsoilnutrientlevelshasapositiveeffectonanimalgroupsatlowlevels,butasthenumberofantsincreases,theirpredatoryimpactshavethebiggereffect—therebycounteractingthepositiveinfluenceviaecosystemengineering."An
8、tsareimportantcomponentsofecosystemsnotonlybecausetheyconstit
