John Spoelstra

Office: Environmental & Information Technology (EIT) 5031
Phone (Waterloo): (519) 888-4567 ext. 37277

Phone (Environment Canada): (905) 336-6246
Email: john.spoelstra@ec.gc.ca
Website: Environment Canada Profile

Research interests

• Sources and fate of nitrogen-based contaminants in groundwater and surface water
• Development and application of stable isotope tools for biogeochemistry research and contaminant source identification
• Impacts of land management on groundwater and surface water quality in agricultural watersheds
• Water quality issues in urbanized watersheds
• Nutrient cycling and fate in forested catchments and wetlands
   

Recent journal publications

Robertson, W.D., T.A. Moore, J. Spoelstra, L. Li, R.J. Elgood, I.D. Clark, S.L. Schiff, R. Aravena and J.D. Neufeld (2012) Natural attenuation of septic system nitrogen by anammox. Ground Water 50(4): 541-553.

Snider, D.M., S.L. Schiff, J.J. Venkiteswaran and J. Spoelstra (2011) Deciphering the oxygen isotopic composition of nitrous oxide produced by nitrification and nitrifier-denitrification. Global Change Biology 18: 356-370.

Bobba, A.G., P.A. Chambers, and J. Spoelstra J. (2010) Environmental impacts in arid and semiarid floodplains. Journal of Environmental Hydrology 18: 1-15.

Snider, D.M., J. Spoelstra, S.L. Schiff, and J.J. Venkiteswaran. (2010) Stable oxygen isotope ratios of nitrate produced from nitrification:  18O-labelled incubations of agricultural and temperate forest soils. Environmental Science & Technology 44: 5358-5364.

Spoelstra, J., S.L. Schiff, R.G. Semkin, D.S. Jeffries, and R.J. Elgood. (2010) Nitrate attenuation in a small temperate wetland following forest harvest. Forest Ecology and Management 259: 2333-2341.

Snider, D.M., S.L. Schiff, and J. Spoelstra. (2009) 15N/14N and 18O/16O stable isotope ratios of nitrous oxide produced during denitrification in temperate forest soils. Geochimica et Cosmochimica Acta 73: 877-888.

Spoelstra, J., S.L. Schiff, P.W. Hazlett, D.S. Jeffries, and R.G. Semkin. (2007) The isotopic composition of nitrate produced from nitrification in a hardwood forest floor. Geochimica et Cosmochimica Acta 71: 3757-3771.

Pardo, L.H., P. Templer, C.L. Goodale, S. Duke, P. Groffman, et al. (2006) Regional assessment of N saturation using foliar and root d15N. Biogeochemistry 80: 143-171.

Foster, N.W., J. Spoelstra, P.W. Hazlett, S.L. Schiff, F.D. Beall, I.F. Creed, and C.A. David. (2005) Heterogeneity in nitrogen cycling within soils in first-order forested catchments at the Turkey Lakes Watershed. Canadian Journal of Forest Research 35: 797-805.

Schiff, S.L., J. Spoelstra, R.G. Semkin, and D.S. Jeffries. (2005) Drought induced pulses of SO42- from a Canadian Shield wetland: Use of d34S and d18O in SO42- to determine sources of S. Applied Geochemistry 20: 691-700.

Spoelstra, J., S.L. Schiff, D.S. Jeffries, and R.G. Semkin. (2004) Effect of storage on the isotopic composition of nitrate in bulk precipitation. Environmental Science & Technology 38: 4723-4727.

Schiff, S.L., K.J. Devito, R.J. Elgood, P.M. McCrindle, J. Spoelstra, and P. Dillon. (2002) Two adjacent catchments: Dramatically different nitrate export. Water Resources Research 38(12): 1292, doi:1029/2000WR000170.

Spoelstra, J., S.L. Schiff, R. Elgood, R.G. Semkin, and D.S. Jeffries. (2001) Tracing the sources of exported nitrate in the Turkey Lakes Watershed using 15N/14N and 18O/16O isotopic ratios. Ecosystems 4: 536-544.

Recent student theses

Senger, N.D. (in progress) Multi-decade comparison of groundwater nitrate in the southern Nottawasaga River Watershed. M.Sc. thesis. University of Waterloo, Waterloo, Ontario, Canada.

Hollingham, M. (2011) Sources of elevated nitrate concentrations in municipal groundwater supplied in Norfolk and Oxford Counties. B.Sc. thesis. University of Waterloo, Waterloo, Ontario, Canada.

Flood, K. (2011) Investigating nitrate in the Innisfil Creek Subwatershed. B.Sc. thesis. University of Waterloo, Waterloo, Ontario, Canada.

Li, L. (2010) Use of N2O and its isotopic composition to investigate nitrogen processes in groundwater. M.Sc. thesis. University of Waterloo, Waterloo, Ontario, Canada.

Thuss, E. (2010) Plant isotopes as indicators of N cycling processes in agricultural fields M.Sc. thesis. Wilfrid Laurier University, Waterloo, Ontario, Canada.

Fiaz, F. (2008) 15N/14N of grasses in the riparian zone of a small agricultural creek: An indicator of denitrification in discharging groundwater? B.Sc. thesis. University of Waterloo, Waterloo, Ontario, Canada.