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Spruce and Peatland Responses Under Changing Environments

Research Issue

Wetlands, especially organic rich peatlands, have historically been massive sinks for carbon but climate change may be changing the source/sink relationship.  If northern peatlands become carbon sources (or even lesser sinks) the possible feedbacks to the atmosphere could have global implications on carbon dioxide levels in the atmosphere.

Our Research

Through collaboration with the U.S. Department of Energy and Oak Ridge National Lab, a large experiment is installed to test the effects of increased soil and air temperature and elevated carbon dioxide levels on northern peatland ecosystems.  The experiment provides a platform for testing mechanisms controlling vulnerability of wetland ecosystems to important climate change variables. The Forest Service’s Marcell Experimental Forest in Northern Minnesota is hosting the Spruce and Peatland Responses Under Changing Environments (SPRUCE) experiment because of its rich history of research on peatlands and long-term hydrological, climatological and chemistry data bases.  The $50 million experiment is funded by the Department of Energy and is projected to run for 10 years. The SPRUCE infrastructure consists of 10 large (40 ft dia., 30 ft tall) open-topped, controlled-environment enclosures. The atmosphere and soil (peat) in the enclosures are maintained at 5 different temperatures (no change, +4, +8, +12, and +16 degrees Fahrenheit) relative to temperatures measured outside the enclosures and carbon dioxide will be approximately doubled in one-half of the chambers throughout the 10 year period of the experiment. Heating of the soil began in June 2014, atmospheric heating began in July 2015 and carbon dioxide additions began in June 2016.

Key science questions being investigated include the following:

• How vulnerable are peatland ecosystems and their component organisms to atmospheric change and changing environments?
• To what degree will changes in plant physiology under elevated CO₂ impact a species’ sensitivity to climate or competitive capacity within the community?
• Will full belowground warming release unexpected amounts of greenhouse gases and solutes from high-carbon-content northern forests?
• What are the critical air and soil temperature response functions for ecosystem processes and their constituent organisms?
• Will ecosystem services (e.g. biogeochemical, hydrological, or societal) be compromised or enhanced by atmospheric and changing environments?

Expected Outcomes

The experiment promises to provide important data on ecosystem response to changing environments that will feed into both ecosystem and global climate models and will better allow us to predict future climate. Better predictions will assist policy makers and the public to make more informed decisions related to mitigation and adaptation to changing environments.

Research Results

We conducted numerous studies to assess peatland vegetation, soil, microbial communities, chemistry, hydrology, gas fluxes and a number of other parameters to characterize the peatland community prior to manipulation.  See links to publications and presentations that have resulted from pre-manipulation studies.  Results from studies that have assessed parameters affected by soil and atmospheric warming are just beginning to come out.

• Oak Ridge National Laboratory SPRUCE website
  • For a list of related publications: http://mnspruce.ornl.gov/content/project-publications

Selected Recent Publications

Curtinrich, Holly J.; Sebestyen, Stephen D.; Griffiths, Natalie A.; Hall, Steven J. 2022. Warming Stimulates Iron-Mediated Carbon and Nutrient Cycling in Mineral-Poor Peatlands. Ecosystems. 25(1): 44-60. https://doi.org/10.1007/s10021-021-00639-3.

Yuan, Fenghui; Wang, Yihui; Ricciuto, Daniel M.; Shi, Xiaoying; Yuan, Fengming; Brehme, Thomas; Bridgham, Scott; Keller, Jason; Warren, Jeffrey M.; Griffiths, Natalie A.; Sebestyen, Stephen D.; Hanson, Paul J.; Thornton, Peter E.; Xu, Xiaofeng. 2021. Hydrological feedbacks on peatland CH4 emission under warming and elevated CO2: A modeling study. Journal of Hydrology. 603: 127137. 12 p. https://doi.org/10.1016/j.jhydrol.2021.127137.

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): e2021JG006511. 17 p. https://doi.org/10.1029/2021JG006511.

Wilson, Rachel M.; Tfaily, Malak M.; Kolton, Max; Johnston, Eric R.; Petro, Caitlin; Zalman, Cassandra A.; Hanson, Paul J.; Heyman, Heino M.; Kyle, Jennifer E.; Hoyt, David W.; Eder, Elizabeth K.; Purvine, Samuel O.; Kolka, Randall K.; Sebestyen, Stephen D.; Griffiths, Natalie A.; Schadt, Christopher W.; Keller, Jason K.; Bridgham, Scott D.; Chanton, Jeffrey P.; Kostka, Joel E. 2021. Soil metabolome response to whole-ecosystem warming at the Spruce and Peatland Responses under Changing Environments experiment. Proceedings of the National Academy of Sciences. 118(25): e2004192118-. https://doi.org/10.1073/pnas.2004192118.

Stelling, Jonathan M.; Sebestyen, Stephen D.; Griffiths, Natalie A.; Mitchell, Carl P.J.; Green, Mark B. 2021. The stable isotopes of natural waters at the Marcell Experimental Forest. Hydrological Processes. 35(10): e14336. 9 p. https://doi.org/10.1002/hyp.14336.

Maillard, François; Fernandez, Christopher W.; Mundra, Sunil; Heckman, Kate; Kolka, Randy; Kauserud, Håvard; Kennedy, Peter G. 2021. Warming drives a 'hummockification' of microbial communities associated with decomposing mycorrhizal fungal necromass in peatlands. New Phytologist. 12 p. https://doi.org/10.1111/nph.17755.

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.

McPartland, Mara Y; Montgomery, Rebecca A; Hanson, Paul J; Phillips, Jana R; Kolka, Randy; Palik, Brian. 2020. Vascular plant species response to warming and elevated carbon dioxide in a boreal peatland. Environmental Research Letters. 15(12): 124066. 12 p. https://doi.org/10.1088/1748-9326/abc4fb.

McPartland, Mara Y.; Falkowski, Michael J.; Reinhardt, Jason R.; Kane, Evan S.; Kolka, Randy; Turetsky, Merritt R.; Douglas, Thomas A.; Anderson, John; Edwards, Jarrod D.; Palik, Brian; Montgomery, Rebecca A. 2019. Characterizing Boreal Peatland Plant Composition and Species Diversity with Hyperspectral Remote Sensing. Remote Sensing. 11, 1685. https://doi.org/10.3390/rs11141685.

Ma, Shuang; Jiang, Jiang; Huang, Yuanyuan; Shi, Zheng; Wilson, Rachel M.; Ricciuto, Daniel; Sebestyen, Stephen D.; Hanson, Paul J.; Luo, Yiqi. 2017. Data-Constrained Projections of Methane Fluxes in a Northern Minnesota Peatland in Response to Elevated CO2 and Warming. Journal of Geophysical Research: Biogeosciences. 122(11): 2841-2861. https://doi.org/10.1002/2017JG003932.

Research Participants

• Randy Kolka, Research Soil Scientist, USFS Northern Research Station
• Stephen Sebestyen, Research Hydrologist, USFS Northern Research Station
• Brian Palik, Research Ecologist, USFS Northern Research Station
• Sue Eggert, Research Aquatic Ecologist, USFS Northern Research Station

Research Partners

• Oak Ridge National Laboratory SPRUCE participant list