37-The microbial ecology of permafrost
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2019-03-20 12:39:12
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37-The microbial ecology of permafrostAnestimated25%ofthelandareaonEarthisunder-lainbypermafrost.Theclassicdefinitionofpermafrostissoilthathasremainedfrozen(thatis,below0°C)foratleast2consecutiveyears.However,someancientper-mafrosthasremainedfrozenduringseveralperiodsofglaciation.Infact,permafrostcanbeupto1–3millionyearsoldintheArcticandevenolderinAntarctica.Dependingonthelocationandclimaticconditionsatthetime,thelandsurfacethatisnowpermafrostwasnotinitiallyfrozenandmayhavebeencoveredwitheithervegetationorwater.Someoftheplantandanimalmate-rialandmicrobialbiomassthataccumulatedduringtheCO2-richatmosphereandwarmperiodsinthehistoryoftheEarthbecamepreservedinthepermafrostdur-ingcoolingandglaciationevents.Althoughtheplantsandanimalsthatbecametrappedduringthistransitionmettheirdemise,currentevidencesuggeststhatmanyofthemicroorganismswereabletoadaptandevenremainactive.Recentresearchsuggeststhatpermafrostregionswillbeaffectedbyincreasesinglobaltemperaturesandsubsequentpermafrostthawwillprobabl
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