Ancient low–molecular-weight organic acids in permafrost fuel rapid carbon dioxide production upon thaw

摘要: Northern permafrost soils store a vast reservoir of carbon, nearly twice that the present atmosphere. Current and projected climate warming threatens widespread thaw these frozen, organic carbon (OC)-rich soils. Upon thaw, mobilized OC in dissolved particulate forms can enter streams rivers, which are important processors conduits for dioxide (CO2) to Here, we demonstrate ancient (DOC) leached from 35,800 y B.P. is rapidly mineralized CO2. During 200-h experiments novel high–temporal-resolution bioreactor, DOC concentration decreased by an average 53%, fueling more than sevenfold increase inorganic (DIC) concentration. Eighty-seven percent loss microbial uptake was derived low–molecular-weight (LMW) acids acetate butyrate. To our knowledge, study first directly quantify high CO2 production rates permafrost-derived LMW mineralization. The observed among highest reported potential importance driving rapid metabolism Pleistocene-age upon outgassing atmosphere nearby inland waters.