Dr. Jason Keller

Dr. Jason Keller

Schmid College of Science and Technology; Biological Sciences,
Expertise: Carbon Cycling; Ecology; Global Change; Greenhouse Gases; Peatland; Salt Marsh;
Office Location: Memorial Hall 303
Phone: (714) 289-2072
University of Notre Dame, Bachelor of Science
University of Notre Dame, Ph.D.

Video Profile


Dr. Jason Keller is an ecologist broadly interested in the flow of carbon and nutrients through ecosystems.  Much of his work explores how ecosystems will respond to ongoing global change.  His current research focuses on the controls of anaerobic decomposition and greenhouse gas dynamics in a variety of wetlands, ranging from northern peatlands to tidal marshes.

Courses Taught:

  • Environmental Seminar Series (ENV205)
  • Environmental Problem Solving: Energy and Matter Flow (ENV330)
  • Senior Research: Data Analysis and Presentation (BIOL494)


  • Chapman University, Wang-Frandkin Professorship for Exceptional Scholarship (2018)
  • Chapman University, Award in Mentorship of Undergraduate Research and Creative Activity (2018)
  • Chapman University, Office of Residence Life and First-Year Experience, My Favorite Professor Award (2017)
  • Chapman University Valerie Scudder Award for Outstanding Achievement in Teaching, Scholarly/Creative Activity and Service to the University (2016)
  • Chapman University Office of Sponsored Research Million Dollar Club (2016)
  • Chapman University Wang-Fradkin Assistant Professorship for Exceptional Scholarship (2013)
  • Chapman University Office of Sponsored Research Young Investigator Award (2012)
  • Chapman University Faculty Excellence Award for Teaching (2012)
  • Chapman University Curriculum Innovation in Sustainability Faculty Teaching Award (2011)
  • Chapman University Valerie Scudder Award for Outstanding Achievement in Teaching, Scholarly/Creative Activity and Service to the University (2011)
  • Chapman University Faculty Excellence Award for Research (2010)
  • Smithsonian Institution Postdoctoral Fellowship (2006-2008)
  • University of Notre Dame, Department of Biological Sciences Award for Outstanding Graduate Research (2006)
  • Arthur J. Schmitt Graduate Fellowship (2000-2005)
  • National Science Foundation Graduate Research Fellowship (2001-2004)

Recent Creative, Scholarly Work and Publications

Brown, M.E., J.K. Keller, and C.R. Whitcraft. 2022. Relationship of Sphaeroma quoianum to sediment characteristics and invertebrate community. Biological Invasions 24:3631-3645.
LeeWays, C., L.L. McCullough, A.M. Hopple, J.K. Keller, and S.D. Bridgham. 2022. Homoacetogenesis competes with hydrogenotrophic methanogenesis for substrates in a peatland experiencing ecosystem warming. Soil Biology & Biochemistry 172: 108759.
Ricciuto, D., X. Xu, X., Shi, Y. Wang, X. Song, C. Schadt, N. Griffiths, J. Mao, J. Warren, P. Thornton, J. Chanton, J. Keller, S. Bridgham, J. Gutknecht, S Sebestyen, A. Finzi, R. Kolka, and P. Hanson. Accepted for Publication. An integrative model for soil bioceochemistry and methane processes I: model structure and sensitivity analysis. Journal of Geophysical Research: Biogeosciences. 126: e2019JG005468.
Yuan, F., Wang, Y., D.M. Ricciuto, X. Shi, Yuan, F., Hanson, P.J., S. Bridgham, J. Keller, P.E. Thorton, and X. Xu. Accepted for publication. An integrative model for soil biogeochemistry and methane processes: II. Warming and elevated CO2 effects on peatland CH4 emissions. Journal of Geophysical Research: Biogeosciences. 126: e2020JG005963.
Waldrop, M.P, J.W. McFarland, K.L.Manies, M.C. Leewis, S.J. Blazewicz, M.C. Jones, R.B. Neumann, J.K. Keller, L. Cohen, E.S. Euskirchen, C. Edgar, M.R. Turetsky, and W.L. Cable. 2021. Carbon fluxes and microbial activities from boreal peatlands experiencing permafrost thaw. Journal of Geophysical Research: Biogeosciences 126: e2020JG005869.
Wilson, R.M., M.M. Tfaily, C.A. Zalman, M.M. Kolton, E. Johnston, C. Petro, P.J. Hanson, H.M. Heyman, J. Kyle, D.W. Hoyt, E.K. Eder, S.O. Purvine, R.K. Kolka, S.D. Sebestyen, N.A. Griffiths, C.W. Schadt, J.K. Keller, S.D. Bridgham, J.P. Chanton, and J.E. Kostka. 2021. Soil metabolome response to whole ecosystem warming at the Spruce and Peatland Responses Under Changing Environments experiment. Proceedings of the National Academy of the United States 118: e2004192118.
Rush, J.E.., C.A. Zalman, G. Woerndle, E.L. Hanna, S.D. Bridgham, and J.K. Keller. 2021. Warming promotes the use of organic matter as an electron acceptor in a peatland. Geoderma 401:115303.
Hopple, A.M., R.M. Wilson, M. Kolton, C.A. Zalman, J.P Chanton, J. Kostka, P.J. Hanson, J.K. Keller, and S.D. Bridgham. 2020. Massive peatland carbon banks vulnerable to rising temperatures. Nature Communications 11:1-7.
Rosenfield, M., J. Funk, J. Keller, C. Clausen and K. Cyphers. 2020. Leaf traits can be used to predict rates of litter decomposition. Oikos 10: 589-1596.
Hanna, E., J.K. Keller, D. Chang, Warren De Bruyn, and C.A. Zalman. 2020. The potential importance of methylated substrates in methane production within three northern Minnesota peatlands. Soil Biology & Biochemistry 50: 107957.
Keller, J.K. 2019. Greenhouse gases. Pages 93 - 106. In: Windham-Myers, L., T. Troxler and S. Crooks (Eds.), A Blue Carbon Primer: The State of Coastal Wetland Science, Practice, and Policy. CRC Press, Boca Raton, FL.
Hopple, A.M., L. Pfeifer-Meister, C.A. Zalman, J.K. Keller, M.M. Tfaily, R.M. Wilson, J.P. Chanton, and S.D. Bridgham. 2019. Does dissolved organic matter or solid peat fuel anaerobic respiration in peatlands? Geoderma 349: 79-87.
Clark, C.D., J.C. Bowen, W.J. de Bruyn, and J.K. Keller. 2019. Optical characterization of chromophoric dissolved organic matter (CDOM) and Fe(II) concentrations in soil porewaters along a channel-bank transect in a salt marsh. Estuaries and Coasts 42:1297-1307.
Rupp, D., E.S. Kane, C. Dieleman, J.K. Keller, and M. Turetsky. 2019. Plant functional group effects on peat carbon cycling in a boreal rich fen. Biogeochemistry 144:305-327.
Keller, J.K. and J. Wade. 2018. No evidence for trace metal limitation on anaerobic carbon mineralization in three peatland soils. Geoderma 314:95-101
Zalman, C.A., N. Meade, J. Chanton, J.E. Kostka, S.D. Bridgham and J.K. Keller. 2018. Methylotrophic methanogenesis in Sphagnum-dominated peatland soils. Soil Biology & Biochemistry 118: 156-160.
Zalman, C., J.K. Keller, M. Tfaily, M. Kolton, L. Pfeifer-Meister, R.M. Wilson, X. Lin, J. Chanton, J.E. Kostka, A. Gill, A. Finzi, A.M. Hopple, B.J.M. Bohannan, and S.D. Bridgham. 2018. Small differences in ombrotrophy control regional-scale variation in methane cycling among Sphagnum-dominated peatlands. Biogeochemistry 139: 155-177.
Bowen, J.C., C.D. Clark, J.K. Keller, and W.J. DeBruyn. 2017. Optical properties of chromophoric dissolved organic matter (CDOM) in surface and pore waters adjacent to an oil well in a Southern California salt marsh. Marine Pollution Bulletin 114:157-168.
Wilson, R.M., M.M. Tfaily, V.I. Rich, J.K. Keller, S.D. Bridgham, C. Medvedeff, L. Meredith, P.J. Hanson, M. Hines, L. Pfeifer-Meister, S.R. Saleska, P. Crill, W.T. Cooper, J.P. Chanton and J.E. Kostka. 2017. Hydrogenation of organic matter as a terminal electron sink sustains high CO2:CH4 production ratios regulating climate feedbacks in boreal peatlands and thawing permafrost. Organic Geochemistry 112: 22-32.
Gabriel. K.N., C.A. Medvedeff, and J.K. Keller. 2017. Microbial organic matter reduction in a peatland soil: the importance of water-table level. BIOS 88: 39-45
Keller, J.K., Medvedeff, C.A. 2016. Soil organic matter, In: Vepraskas, M.J., Craft, C.B., Richardson, J.L. (Eds.), Wetland Soils: Genesis, Hydrology, Landscapes, and Classification, Second Edition. CRC Press, Boca Raton, FL. Pages 165-188.
Ye, R., J.K. Keller, Q. Jin, B.J.M. Bohannan and S.D. Bridgham. 2016. Peatland types influence the inhibitory effect of a humic substance analog on methane production. Geoderma 265:131-140
Wang, S., Q. Zhuang, Z. Yu, S. Bridgham, J.K. Keller, and P. Hanson. 2016. Quantifying peat accumulation in Alaska using a process-based biogeochemistry model. Journal of Geophysical Research – Biogeosciences 121: 2172-2185.
Wilson, R.M., A.M. Hopple, M.M. Tfaily, S.D. Sebestyen, C.W. Schadt, L. Pfeifer-Meister, C. Medvedeff, K.J. McFarlane, J.E. Kostka, M. Kolton, R. Kolka, L.A. Kluber, J.K. Keller, T.P. Guilderson, N.A. Griffiths, J.P. Chanton, S.D. Bridgham and P.J. Hanson. 2016. Stability of a peatland carbon bank to rising temperatures. Nature Communications 7:13723.
Medvedeff, C.A., S.D. Bridgham, L. Pfeifer-Meister and J.K. Keller. 2015. Can Spahgnum leachate chemistry explain differences in anaerobic decomposition in peatlands? Soil Biology & Biochemistry 86:34-41.
Keller, J.K., T. Anthony, D. Clark, K. Gabriel, D. Gamalath, R. Kabala, J. King, L. Medina and M. Nguyen. 2015. Soil organic carbon and nitrogen storage in two southern California salt marshes: the role of pre-restoration vegetation. Bulletin of the Southern California Academy of Sciences 114(1).
Ye, R., Q. Jin, B. Bohannan, J.K. Keller, and S.D. Bridgham. 2014. Homoacetogenesis: A potentially underappreciated carbon pathway in peatlands. Soil Biology & Biochemistry 68:385-391.
Clark, C.D., P. Aiona, J.K. Keller and W.J. DeBruyn. 2014. Optical characterization and distribution of chromophoric dissolved organic matter (CDOM) in soil porewater from a salt marsh ecosystem. Marine Ecology Progress Series 516:71-83.
Bridgham, S.D., H. Cadillo-Quiroz, J.K. Keller and Q. Zhuang. 2013. Methane emissions from wetlands: biogeochemical, microbial, and modeling perspectives from local to global scales. Global Change Biology 19:1325-1346
Keller, J.K. and K.K. Takagi. 2013. Solid-phase organic matter reduction regulates anaerobic decomposition in bog soil. Ecosphere 4(5):54.
Weiler, C.S., J.K. Keller and C. Olex. 2012. Personality type differences between Ph.D. climate researchers and the general public: implications for effective communication. Climatic Change 112:233-242.
Iversen, C.M., J.K. Keller, C.T. Garten, and R.J. Norby. 2012. Deep root inputs under elevated [CO2] may increase soil C and N storage. Global Change Biology. 18:1684-1697.
Ye, R., Q. Jin, B. Bohannan, J.K. Keller, S.A. McAllister and S.D. Bridgham. 2012. pH controls over anaerobic carbon mineralization, the efficiency of methane production and methanogenic pathways in peatlands across an ombrotrophic-minerotrophic gradient. Soil Biology & Biochemistry 54:36-47.
Keller, J.K., K.K. Takagi, M.E. Brown, K.N. Stump, C.G. Takahashi, W. Joo, K.L. Au, C.C. Calhoun, R.K. Chundu, K. Hokutan, J.M. Mosolf and K. Roy. 2012. Soil organic carbon storage in restored salt marshes in Huntington Beach, California. Bulletin of the Southern California Academy of Sciences 111(2):153-161.
Emerson, D., W. Bellows, J.K. Keller, A.E. Sutton-Grier, and J.P. Megonigal. 2013. Anaerobic metabolism in tidal freshwater wetlands: II. Effects of plant removal on Archaeal microbial communities. Estuaries and Coasts 36:471-481.
Keller, J.K., A.E. Sutton-Grier, A. Bullock, and J.P. Megonigal. 2013. Anaerobic metabolism in tidal freshwater wetlands: I. Plant removal effects on iron reduction and methanogenesis. Estuaries and Coasts 36:457-470.
Sutton-Grier, A.E., J.K. Keller, R. Koch, C. Gilmour, and J.P. Megonigal. 2011. Electron donors and acceptors influence anaerobic soil organic matter mineralization in tidal marshes. Soil Biology and Biochemistry 43: 1576-1583.
Rabenhorst, M.C., J.P. Megonigal, and J.K. Keller. 2010. Synthetic iron oxides for documenting sulfide in marsh pore water. Soil Science Society of America Journal 74:1383-1388.
Keller, J.K., P.B. Weisenhorn*, and J.P. Megonigal. 2009. Humic acids as electron acceptors in wetland decomposition. Soil Biology & Biochemistry 41:1518-1522. (* = student collaborator)
Keller, J.K., A.A. Wolf*, P.B. Weisenhorn*, B.G. Drake, and J.P. Megonigal. 2009. Elevated CO2 affects porewater chemistry in a brackish marsh. Biogeochemistry 96:101-117. (* = student collaborator)
Ma, S., G.W. Luther III, J. Keller, A.S. Madison E. Metzger, J.P. Megonigal, and D. Emerson. 2008. Solid-state Au/Hg microelectrode for the investigation of Fe and Mn cycling in a freshwater wetland: implications for methane production. Electroanalysis 20(3):233-239.
Chen, J., S.D. Bridgham, J. Keller, J. Pastor, A. Noormets, and J.F. Weltzin. 2008. Temperature Responses to Infrared-Loading and Water Table Manipulations in Peatland Mesocosms. Journal of Integrative Plant Biology 50(11):1484-1496.
Bridgham, S.D., J.P. Megonigal, J.K. Keller, N.B. Bliss, and C. Trettin. 2007. Wetlands. In: The First State of the Carbon Cycle Report (SOCCR): The North American Carbon Budget and Implications for the Global Carbon Cycle. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research [King, A.W., L. Dilling, G.P. Zimmerman, D.M. Fairman, R.A. Houghton, G. Marland, A.Z. Rose, and T.J. Wilbanks (eds.)]. National Oceanic and Atmospheric Administration, National Climatic Data Center, Asheville, NC, USA, pp. 139-148.
Keller, J.K. and S.D. Bridgham. 2007. Pathways of anaerobic carbon cycling across an ombrotrophic-minerotrophic peatland gradient. Limnology and Oceanography 52:96-107.
Weltzin, J.F., R.T. Belote, L.M. Williams, J.K. Keller, and E.C. Engel. 2006. Authorship in ecology: attribution, accountability, and responsibility. Frontiers in Ecology and the Environment 4:435-441.
Bridgham, S.D., J.P. Megonigal, J.K. Keller, N.B. Bliss, and C. Trettin. 2006. The carbon balance of North American wetlands. Wetlands 26(4):889-916.
Keller, J.K., A.K. Bauers*, S.D. Bridgham, L.E. Kellogg, and C.M. Iversen. 2006. Nutrient control of microbial carbon cycling along an ombrotrophic-minerotrophic peatland gradient. Journal of Geophysical Research 111, G03006, doi:10.1029/2005JG000152. (* = student collaborator)
Weltzin, J.F.*, J.K. Keller*, S.D. Bridgham, J. Pastor, P.B. Allen, and J. Chen. 2005. Litter controls plant community composition in a northern fen. Oikos 110:537-546. (* = authors contributed equally)
Keller, J.K., S.D. Bridgham, C.T. Chapin, and C.M. Iversen. 2005. Limited effects of long-term fertilization on carbon mineralization in a Minnesota fen. Soil Biology & Biochemistry 37:1197-1204.
Keller, J.K., J.R. White, S.D. Bridgham, and J. Pastor. 2004. Climate change effects on carbon and nitrogen mineralization in peatlands through changes in soil quality. Global Change Biology 10:1053-1064.