Negligible cycling of terrestrial carbon in many lakes of the arid circumpolar landscape

摘要: High-latitude environments store nearly half of the planet’s below-ground organic carbon (OC), mostly in perennially frozen permafrost soils. Climatic changes drive increased export terrestrial OC into many aquatic networks, yet role that circumpolar lakes play mineralizing this is unclear. Here we directly evaluate ecosystem-scale cycling for interior Alaska. This arid, low-relief lake landscape representative over a quarter total northern area, but greatly under-represented current studies. Contrary to projections based on work other regions, studied had negligible carbon; they received little from ancient soils, and small net contribution watershed balance. Instead, most recycled large quantities internally derived fixed atmospheric CO2, underscoring their importance as critical sites material energy provision regional food webs. Our findings deviate prevailing paradigm are hotspots processing. The shallow hydrologically disconnected nature arid landscapes isolates them processing under climatic conditions. Many organic-poor have carbon, according metabolic analyses Yukon Flats Basin.