Department of Earth Ocean and Atmospheric Science Florida State University Tallahassee FL USA
Oak Ridge National Laboratory Environmental Sciences Division Oak Ridge TN USA
Lawrence Livermore National Laboratory Livermore CA USA
US Department of Agriculture Forest Service Northern Research Station Grand Rapids MN USA
Institute of Ecology and Evolution University of Oregon Eugene OR USA, Pacific Northwest National Laboratory Smithsonian Environmental Research Center Edgewater MD USA
Department of Environmental Science University of Arizona Tucson AZ USA
School of Biological Sciences Georgia Institute of Technology Atlanta GA USA
Institute of Ecology and Evolution University of Oregon Eugene OR USA
Schmid College of Science and Technology Biological Sciences Chapman University Orange CA USA
Climate warming is expected to accelerate peatland degradation and release rates of carbon dioxide (CO 2 ) and methane (CH 4 ). Spruce and Peatlands Responses Under Changing Environments is an ecosystem‐scale climate manipulation experiment, designed to examine peatland ecosystem response to climate forcings. We examined whether heating up to +9 °C to 3 m‐deep in a peat bog over a 7‐year period led to higher C turnover and CO 2 and CH 4 emissions, by measuring 14 C of solid peat, dissolved organic carbon (DOC), CH 4 , and dissolved CO 2 (DIC). DOC, a major substrate for heterotrophic respiration, increased significantly with warming. There was no 7‐year trend in the DI 14 C of the ambient plots which remained similar to their DO 14 C. At +6.75 °C and +9 °C, the 14 C of DIC, a product of microbial respiration, initially resembled ambient plots but became more depleted over 7 years of warming. We attributed the shifts in DI 14 C to the increasing importance of solid phase peat as a substrate for microbial respiration and quantified this shift via the radiocarbon mass balance. The mass‐balance model revealed increases in peat‐supported respiration of the catotelm depths in heated plots over time and relative to ambient enclosures, from a baseline of 20%–25% in ambient enclosures, to 35%–40% in the heated plots. We find that warming stimulates microorganisms to respire ancient peat C, deposited under prior climate (cooler) conditions. This apparent destabilization of the large peat C reservoir has implications for peatland‐climate feedbacks especially if the balance of the peatland is tipped from net C sink to C source.
Wilson, Rachel M., et al. "Radiocarbon Analyses Quantify Peat Carbon Losses With Increasing Temperature in a Whole Ecosystem Warming Experiment." Journal of Geophysical Research. Biogeosciences, vol. 126, no. 11, Nov. 2021. https://doi.org/10.1029/2021JG006511
Wilson, Rachel M., Griffiths, Natalie A., Visser, Ate, McFarlane, Karis J., Sebestyen, Stephen D., Oleheiser, Keith C., Bosman, Samantha, Hopple, Anya M., Tfaily, Malak M., Kolka, Randall K., Hanson, Paul J., Kostka, Joel E., Bridgham, Scott D., Keller, Jason K., & Chanton, Jeffrey P. (2021). Radiocarbon Analyses Quantify Peat Carbon Losses With Increasing Temperature in a Whole Ecosystem Warming Experiment. Journal of Geophysical Research. Biogeosciences, 126(11). https://doi.org/10.1029/2021JG006511
Wilson, Rachel M., Griffiths, Natalie A., Visser, Ate, et al., "Radiocarbon Analyses Quantify Peat Carbon Losses With Increasing Temperature in a Whole Ecosystem Warming Experiment," Journal of Geophysical Research. Biogeosciences 126, no. 11 (2021), https://doi.org/10.1029/2021JG006511
@article{osti_1829752,
author = {Wilson, Rachel M. and Griffiths, Natalie A. and Visser, Ate and McFarlane, Karis J. and Sebestyen, Stephen D. and Oleheiser, Keith C. and Bosman, Samantha and Hopple, Anya M. and Tfaily, Malak M. and Kolka, Randall K. and others},
title = {Radiocarbon Analyses Quantify Peat Carbon Losses With Increasing Temperature in a Whole Ecosystem Warming Experiment},
annote = {Abstract Climate warming is expected to accelerate peatland degradation and release rates of carbon dioxide (CO 2 ) and methane (CH 4 ). Spruce and Peatlands Responses Under Changing Environments is an ecosystem‐scale climate manipulation experiment, designed to examine peatland ecosystem response to climate forcings. We examined whether heating up to +9 °C to 3 m‐deep in a peat bog over a 7‐year period led to higher C turnover and CO 2 and CH 4 emissions, by measuring 14 C of solid peat, dissolved organic carbon (DOC), CH 4 , and dissolved CO 2 (DIC). DOC, a major substrate for heterotrophic respiration, increased significantly with warming. There was no 7‐year trend in the DI 14 C of the ambient plots which remained similar to their DO 14 C. At +6.75 °C and +9 °C, the 14 C of DIC, a product of microbial respiration, initially resembled ambient plots but became more depleted over 7 years of warming. We attributed the shifts in DI 14 C to the increasing importance of solid phase peat as a substrate for microbial respiration and quantified this shift via the radiocarbon mass balance. The mass‐balance model revealed increases in peat‐supported respiration of the catotelm depths in heated plots over time and relative to ambient enclosures, from a baseline of 20%–25% in ambient enclosures, to 35%–40% in the heated plots. We find that warming stimulates microorganisms to respire ancient peat C, deposited under prior climate (cooler) conditions. This apparent destabilization of the large peat C reservoir has implications for peatland‐climate feedbacks especially if the balance of the peatland is tipped from net C sink to C source. },
doi = {10.1029/2021JG006511},
url = {https://www.osti.gov/biblio/1829752},
journal = {Journal of Geophysical Research. Biogeosciences},
issn = {ISSN 2169-8953},
number = {11},
volume = {126},
place = {United States},
publisher = {American Geophysical Union (AGU)},
year = {2021},
month = {11}}
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 363, Issue 1837https://doi.org/10.1098/rsta.2005.1671
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 365, Issue 1856https://doi.org/10.1098/rsta.2007.2035