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1、AntsHaveBigImpactonEnvironmentas"EcosystemEngineers" ResearchbytheUniversityofExeter1hasrevealedthatantshaveabigimpactontheirlocalenvironmentasaresultoftheiractivityas"ecosystemengineers"andpredators.Thestudy,publishedintheJournalofAnimalEcology,foundthatantshavetwodistincteffectsontheirlocalenviro
2、nment. Firstly,throughmovingofsoilbynestbuilding2activityandbycollectingfoodtheyaffectthelevelofnutrientsinthesoil.Thiscanindirectlyimpactthelocalpopulationsofmanyanimalgroups,fromdecomposerstospeciesmuchhigherupthefoodchain. Secondly,theypreyonawiderangeofotheranimals,includinglargerpreywhichcanb
3、eattackedbyvastnumbersofantworkers. DirkSanders,anauthorofthestudyfromtheuniversity'sCentreforEcologyandConservation,said:"Antsareveryeffectivepredatorswhichthriveinhugenumbers.They'realsoveryterritorial3andveryaggressive,defendingtheirresourcesandterritoryagainstotherpredators.Allofthismeanstheyha
4、veastronginfluenceontheirsurroundingarea." "Inthisresearch,westudiedforthefirsttimehowbigthisimpactisandthesubtletiesofit.Whatwefoundisthatdespitebeingpredators,theirpresencecanalsoleadtoanincreaseindensityanddiversityofotheranimalgroups4.Theygenuinelyplayakeyroleinthelocalenvironment,havingabiginf
5、luenceonthegrasslandfoodweb,"Sanderssaid. Thestudy,carriedoutinGermany,studiedtheimpactofthepresenceofdifferentcombinationsanddensitiesofblackgardenantsandcommonredants,bothspecieswhichcanbefoundacrossEurope,includingintheUK.Itfoundthatalowdensityofantsinanareaincreasedthediversityanddensityofother
6、animalsinthelocalarea,particularlythedensityofherbivoresanddecomposers.Athigherdensitiesantshadnoortheoppositeeffect,showingthatpredationiscounteractingthepositiveinfluence. DrFrankvanVeen,anotherauthoronthestudy,said:"Whatwefindisthattheimpactofantsonsoilnutrientlevelshasapositiveeffectonanimalgro
7、upsatlowlevels,butasthenumberofantsincreases,theirpredatoryimpactshavethebiggereffect-therebycounteractingthepositiveinfluenceviaecosystemengineering." Antsareimportantcomponentsofecosystemsnotonlybe
