Rapid Net Carbon Loss From a Whole‐Ecosystem Warmed Peatland

Abstract

Abstract To evaluate boreal peatland C losses from warming, novel technologies were used to expose intact bog plots in northern Minnesota to a range of future temperatures (+0°C to +9°C) with and without elevated CO2 (eCO2). After 3 years, warming linearly increased net C loss at a rate of 31.3 g C·m−2·year−1·°C−1. Increasing losses were associated with increased decomposition and corroborated by measures of declining peat elevation. Effects of eCO2 were minor. Results indicate a range of C losses from boreal peatlands 4.5 to 18 times faster than historical rates of accumulation, with substantial emissions of CO2 and CH4 to the atmosphere. A model of peatland C cycle captured the temperature response dominated by peat decomposition under ambient CO2, but improvements will be needed to predict the lack of observable responses to elevated CO2 concentrations thus far.

Keywords

• carbon
• peatland
• warming
• experiment
• elevated CO2
• modeling