Rapid Net Carbon Loss From a Whole‐Ecosystem Warmed Peatland

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. Article includes 19 pages of supplemental materials.

Citation

Hanson, Paul J.; Griffiths, Natalie A.; Iversen, Colleen M.; Norby, Richard J.; Sebestyen, Stephen D.; Phillips, Jana R.; Chanton, Jeffrey P.; Kolka, Randall K.; Malhotra, Avni; Oleheiser, Keith C.; Warren, Jeffrey M.; Shi, Xiaoying; Yang, Xiaojuan; Mao, Jiafu; Ricciuto, Daniel M. 2020. Rapid Net Carbon Loss From a Whole Ecosystem Warmed Peatland. AGU Advances. 1(3): e2020AV000163. 18 p. https://doi.org/10.1029/2020av000163.