University of California, Riverside

Environmental Sciences

James O. Sickman

James O. Sickman

James Sickman Photo

Department Vice-Chair
Associate Professor of Hydrology

Academic Degrees:

  • Ph.D., Watershed Biogeochemistry, U.C. Santa Barbara, 2001
  • M.A., Aquatic and Ecosystem Science, U.C. Santa Barbara, 1991
  • B.A., Aquatic Biology, U.C. Santa Barbara, 1983


  • Watershed hydrology and biogeochemistry, application of stable and radioisotopes to environmental science.

Research Group:

  • Graduate Students
    Andrea Heard - Ph.D., Environmental Sciences program
    Critical loads for atmospheric nutrient deposition in the Sierra Nevada
    Amanda James - Ph.D, Environmental Sciences Program
    Utilizing native plant species as biological sensors for atmospheric deposition
  • Other
    Peter Homyak - Ph.D. 2012, University of California, Riverside - Post Doctoral Researcher
    Steve Sadro - Post Doctoral Researcher
    Studies lake foodwebs and metabolism in the Sierra Nevada
    Danuta Bennett - Assistant Researcher
    Diatomist and aquatic ecologist
    Kevin Skeen - Staff Research Associate
    Field manager for Sierra Nevada research
    Forugh Arsalan - Undergraduate researcher
    Krystal Vasquez - Undergraduate researcher

Representative Publications:

  • Homyak, P.M, Sickman, J.O., and J.M. Melack. Pools, transformations and sources of P in high elevations soils: Implications for nutrient transfer to Sierra Nevada lakes. In press in Geoderma.
  • Sickman, J.O., Bennett, D.M., Lucero, D.M., Whitmore, T.J., Kenney, W.F. 2013. Diatom-inference models for acid neutralizing capacity and nitrate based on 41 calibration lakes in the Sierra Nevada, California, USA. Journal of Paleolimnology. DOI: 10.1007/s10933-013-9711-0.
  • Jepsen, S.M., Molotch, N.P., Williams, M.W., Rittger, K.E., Sickman J.O. 2012. Interannual variability of snowmelt in the Sierra Nevada and Rocky Mountains, USA (1996-2007): Examples from two alpine watersheds. Water Resources Research. DOI: 10.1029/2011WR011006.
  • Albertin, A., Sickman, J.O., Pinowska, A., and R.J. Stevenson. 2012. Identification of nitrogen sources and transformations within karst springs using isotope tracers of nitrogen. Biogeochemistry. DOI: 10.1007/s10533-011-9592-0.
  • Vicars, W., and J.O. Sickman. 2011. Mineral dust transport to the Sierra Nevada, California: Loading rates and potential source areas. Journal of Geophysical Research, Biogeosciences: DOI:10.1029/2010JG001394.

Courses Taught:

  • ENSC 001 Introduction to Environmental Sciences: Natural Resources
  • ENSC 163 Physical Hydrology
  • ENSC 218 Isotopes in Ecology and Environmental Science
  • ENSC 227 Global Change and the Earth System

Graduate Program Affiliations and Research Focus Areas:


More Information

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

Department Information

Enviromental Sciences
Geology 2258

Tel: (951) 827-5116
Fax: (951) 827-3993