Persistent negativeeffectsofpesticidesonbiodiversityandbiological control potentialonEuropeanfarmland
Résumé
During thelast50years,agriculturalintensificationhascaused manywildplantandanimalspeciestogoextinctregionally or nationallyandhasprofoundlychangedthefunctioningofagro-ecosystems.Agricultural intensificationhasmany components, suchaslossoflandscapeelements,enlargedfarmand fieldsizesandlargerinputsoffertilizerandpesticides. However, verylittleisknownabouttherelative contributionofthesevariablesto thelarge-scalenegativeeffectson biodiversity. Inthisstudy,wedisentangled theimpactsofvariouscomponentsofagriculturalintensificationonspecies diversity ofwildplants,carabidsandground-nestingfarmlandbirdsandonthebiologicalcontrolofaphids. In aEurope-widestudyineightWestandEastEuropeancountries,wefoundimportantnegativeeffectsof agriculturalintensificationonwildplant,carabidandbirdspeciesdiversityandonthepotentialforbiologicalpest control,asestimatedfromthenumberofaphidstakenbypredators.Ofthe13componentsofintensificationwe measured,useofinsecticidesandfungicideshadconsistentnegativeeffectsonbiodiversity.Insecticidesalsoreduced the biologicalcontrolpotential.Organicfarmingandotheragri-environmentschemesaimingtomitigatethenegative effectsofintensivefarmingonbiodiversitydidincreasethediversityofwildplantandcarabidspecies,but–contrary to ourexpectations–notthediversityofbreedingbirds. We concludethatdespitedecadesofEuropeanpolicytobanharmfulpesticides,thenegativeeffectsofpesticideson wild plantandanimalspeciespersist,atthesametimereducingtheopportunitiesforbiologicalpestcontrol.If biodiversityistoberestoredinEuropeandopportunitiesaretobecreatedforcropproductionutilizingbiodiversity- based ecosystemservicessuchasbiologicalpestcontrol,theremustbeaEurope-wideshifttowardsfarmingwith minimaluseofpesticidesoverlargeareas.