Profile – Sean M. Schaeffer

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Sean M. Schaeffer

Job Title:

Assistant Professor


Phone Number:



Google Scholar Profile


Dr. Sean Schaeffer is an Assistant Professor in the Department of Biosystems Engineering and Soil Science at the University of Tennessee, Knoxville. He obtained a B.Sc. from the University of Utah, a M.Sc. from the University of Arizona, and a Ph.D. from the University of Arkansas. Prior to arriving in Tennessee, he was a Postdoctoral Scholar and Project Scientist at the University of California, Santa Barbara. Dr. Schaeffer is a soil biogeochemist with research interests in the coupled cycling of carbon and nitrogen and how they control the long-term stability of soil organic matter. His current research includes USDA and NSF-funded projects studying: 1) microbial nitrogen assimilation and allocation under drought conditions, 2) the effects of carcass decomposition on ecosystem nitrogen cycles, and 3) nitrogen retention in agroecosystems. His other research interests include: the role of viruses in terrestrial biogeochemical cycles, and the application of novel stable isotope tracer techniques to study ecosystem processes.

Research Areas:

  • Soil Biogechemistry
  • Carbon Cycling
  • Nitrogen Cycling
  • Microbial Ecology
  • Drought
  • Climate Change

Current N-related Projects:

  • Mitigating nutrient losses from agroecosystems: biotic and abiotic mechanisms of nitrogen cycling under conservation agriculture management


Zhang, X, W Dong, X Dai, SM Schaeffer, F Yang, M Radosevich, L Xu, X Liu, X Sun (2015). Responses of absolute and specific soil enzyme activities to long term additions of organic and mineral fertilizer. Science of the Total Environment, 536:59-67
Mbuthia, LW, V Acosta-Martinez, JM Debryun, SM Schaeffer, D Tyler, E Odoi, °M Mpheshea, F Walker, N Eash (2015). Long term tillage, cover crop, and fertilization effects on microbial community structure, activity: Implications for soil quality. Soil Biology and Biochemistry, 89:24-34
Cobaugh, K, SM Schaeffer, JM DeBruyn (2015). Functional and structural succession of soil microbial communities below decomposing human cadavers. PLoS ONE 10(6):e0130201. doi:10.1371/journal.pone.0130201
Dong, W-Y, X Zhang, X Dai, X Fu, F Yang, X Liu, X Sun, X Wen, and SM Schaeffer (2014). Changes in soil microbial community composition in response to fertilization of paddy soils in subtropical China. Applied Soil Ecology, 84:140-147
Schaeffer, SM, E Sharp, JP Schimel, and JM Welker (2013). Soil-plant N processes in a High Arctic ecosystem, NW Greenland are altered by long-term experimental warming and higher rainfall. Global Change Biology, 19:3529-3539
Schaeffer, SM, S Ziegler, J Belnap, and RD Evans (2012). Effects of Bromus tectorum invasion on microbial carbon and nitrogen cycling in two adjacent undisturbed arid grassland communities. Biogeochemistry, 111:427-441
Hultine, KR, TL Jackson, KG Burtch, SM Schaeffer, and JR Ehleringer (2008). Elevated stream inorganic nitrogen impacts on a dominant riparian tree species: results from an experimental riparian stream system. Journal of Geophysical Research, 113, G04025, doi:10.1029/2008JG000809
Schaeffer, SM, SA Billings, and RD Evans (2007). Laboratory incubations reveal potential responses of soil nitrogen cycling to changes in soil C and N availability in Mojave Desert soils exposed to elevated atmospheric CO2. Global Change Biology, 13:854-865
Schaeffer, SM and RD Evans (2005). Pulses of soil carbon and nitrogen affect soil nitrogen dynamics in an arid Colorado Plateau shrubland. Oecologia, 145:425-433
9. Austin, AT, ML Yahdijan, JM Stark, J Belnap, A Porporato, IC Burke, U Choromanska, D Ravetta, and SM Schaeffer (2004). Water pulses and biogeochemical cycles in arid and semiarid ecosystems. Oecologia, 141:221-235
Billings, SA, SM Schaeffer, and RD Evans (2004). Soil microbial activity and N availability with elevated CO2 in Mojave Desert soils. Global Biogeochemical Cycles, 18:GB1011
Schaeffer, SM, SA Billings, and RD Evans (2003). Responses of soil nitrogen dynamics in a Mojave Desert ecosystem to manipulations in soil carbon and nitrogen availability. Oecologia, 134:547-553
Billings, SA, SM Schaeffer, and RD Evans (2002). Trace N gas losses and N mineralization in an intact Mojave Desert ecosystem with elevated CO2. Soil Biology and Biochemistry, 34:1777-1784