Fire frequency is increasing with climate warming in the boreal regions of interior Alaska, with short fire return intervals (< 50 years) becoming more common. Recent studies suggest these “reburns” will reduce the insulating surface organic layer (SOL) and seedbanks, inhibiting black spruce regeneration and increasing deciduous cover. These changes are projected to amplify soil warming, increasing mineral soil organic carbon...

Microorganisms are major constituents of the total biomass in permafrost regions, whose underlain soils are frozen for at least two consecutive years. To understand potential microbial responses to climate change, here we examined microbial community compositions and functional capacities across four soil depths in an Alaska tundra site. We showed that a 5‐year warming treatment increased soil thaw depth by 25.7% ( p = .011) w...

Quantifying soil organic carbon ( SOC ) decomposition under warming is critical to predict carbon–climate feedbacks. According to the substrate regulating principle, SOC decomposition would decrease as labile SOC declines under field warming, but observations of SOC decomposition under warming do not always support this prediction. This discrepancy could result from varying changes in SOC components and soil microbial communit...

Rapid Arctic warming is expected to increase global greenhouse gas concentrations as permafrost thaw exposes immense stores of frozen carbon (C) to microbial decomposition. Permafrost thaw also stimulates plant growth, which could offset C loss. Using data from 7 years of experimental Air and Soil warming in moist acidic tundra, we show that Soil warming had a much stronger effect on CO 2 flux than Air warming. Soil warming ca...

High‐latitude ecosystems store approximately 1700 Pg of soil carbon (C), which is twice as much C as is currently contained in the atmosphere. Permafrost thaw and subsequent microbial decomposition of permafrost organic matter could add large amounts of C to the atmosphere, thereby influencing the global C cycle. The rates at which C is being released from the permafrost zone at different soil depths and across different physi...

Hurricane disturbances have profound impacts on ecosystem structure and function, yet their effects on ecosystem CO 2 exchange have not been reported. In September 2004, our research site on a fire‐regenerated scrub‐oak ecosystem in central Florida was struck by Hurricane Frances with sustained winds of 113 km h −1 and wind gusts as high as 152 km h −1 . We quantified the hurricane damage on this ecosystem resulting from defol...