Photo of Elyn Humphreys

Elyn Humphreys

Associate Professor, Graduate Studies Program Supervisor and Student Advisor

Degrees:B.Sc. Guelph, M.Sc., Ph.D. (UBC)
Phone:613-520-2600 x 4125
Office:Loeb B359


Elyn Humphreys studies the exchange of carbon dioxide, water vapour, and energy between ecosystems and the atmosphere and the effects of natural and human-induced disturbances on this type of ecosystem function. Her research is currently focused on interactions between climate change and peatland ecosystems in temperate and arctic regions. These ecosystems have vast stores of soil carbon but small changes in climate have the potential to alter the subtle balance between carbon uptake through photosynthesis and loss through respiration.

Elyn received her B.Sc. at the University of Guelph in Plant Biology and then went to the University of British Columbia where she completed her M.Sc. and Ph.D with the biometeorology research group in the Faculty of Land and Food Science. Before arriving at Carleton in 2005, she held an NSERC Postdoctoral Fellowship the Dept. of Geography at Trent University.

Research Interests

  • Soil-plant-atmosphere interactions
  • Microclimatology

2016-2017 Courses

  • GEOG 2013 Weather and Water
  • GEOG 4104 Microclimatology

Recent Publications

Brümmer, C., Black, T.A., Jassal, R.S., Grant, N.J., Spittlehouse, D.L., Chen, B., Nesic, Z., Amiro, B.D., Arain, M.A., Barr, A.G., Bourque, C.P.-A., Coursolle, C., Dunn, A.L., Flanagan, L.B., Humphreys, E.R., Lafleur, P.M., Margolis, H.A., McCaughey, J.H., and Wofsy, S.C.  2012. How climate and vegetation type influence evapotranspiration and water use efficiency in Canadian forest, peatland and grassland ecosystems, Agricultural and Forest Meteorology, 153: 14-30.

Chong, M., Humphreys, E.R., and Moore, T.R. 2012.  Microclimatic response to increasing shrub cover and its effect on Sphagnum CO2 exchange in a bog.  Ecoscience, 19: 89-97.

Grant, R.F., Humphreys, E.R., Lafleur, P.M., and Dimitrov, D. D. 2012.  Ecological Controls on Net Ecosystem Productivity of a Mesic Arctic Tundra under Current and Future Climates, Journal of Geophysical Research – Biogeosciences, G01031, doi:10.1029/2010JG001555.

Juszczak, R., Humphreys, E., Acosta, M., Michalak, M., Kayzer, D., and Olejnik, J.  Ecosystem respiration in a heterogeneous temperate peatland and its sensitivity to peat temperature and water table depth.  Plant Soil, doi: 10.1007/s11104-012-1441-y. Accepted August 22, 2012.

Knox, S.H., Carey, S.K., and Humphreys, E.R. 2012.  Snow surface energy exchanges and snowmelt in a shrub-covered bog in eastern Ontario, Canada. Hydrological Processes, doi: 10.1002/hyp.9289

Lafleur, P.M., Humphreys, E.R., Myklebust, M.C., St. Louis, V.L., Papakyriakou, T., Poissant, L., Barker, J.D., Pilote, M. and Swystun, K.A. 2012. Variation in peak growing season net ecosystem production across the Canadian Arctic.  Environmental Science and Technology,

Lai, D.Y.F., Roulet, N.T., Humphreys, E.R., Moore, T.R., and Dalva, M.  2012.  The effect of atmospheric turbulence and chamber deployment period on autochamber CO2 and CH4 flux measurements in an ombrotrophic peatland.  Biogeosciences, 9: 3305-3322.

Schaefer, K and 50 others.  2012.  A model-data comparison of gross primary productivity:  Results from the North American Carbon Program site synthesis.  Journal of Geophysical Research, 117, doi: 10.1029/2012JG001960.

Wu, J., N. T. Roulet, M. Nilsson, P. Lafleur, and Humphreys, E. 2012. Simulating the Carbon Cycling of Northern Peatlands Using a Land Surface Scheme Coupled to a Wetland Carbon Model (CLASS3W-MWM), Atmosphere-Ocean, 50: 487-506.

Humphreys, E. R. and Lafleur, P.M. 2011. Does earlier snowmelt lead to greater CO2 sequestration in two low Arctic tundra ecosystems? Geophysical Research Letters, 38, L09703, doi:10.1029/2011GL047339.

Loranty, M. M., Goetz, S.J., Rastetter, E.B., Rocha, A.V., Shaver, G.R., Humphreys, E.R., and Lafleur, P.M. 2011.  Scaling an instantaneous model of tundra NEE to the Arctic landscape.  Ecosystems, 14: 76-93.

Moore, T.R., De Young, A., Bubier, J., Humphreys, E.R., Lafleur, P.M., Roulet, N.T.  2011.  A multi-year record of methane flux at the Mer Bleue bog, southern Canada, Ecosystems, 14: 646-657.

Strilesky, S.L. and Humphreys, E.R. 2011. A comparison of the net ecosystem exchange of carbon dioxide and evapotranspiration for open and treed portions of a temperate peatland, Agricultural and Forest Meteorology, doi:10.1016/j.agrformet.2011.06.006

Wu, J., N. T. Roulet, T. R. Moore, P. Lafleur, and Humphreys, E. 2011. Dealing with microtopography of an ombrotrophic bog for simulating ecosystem-level CO2 exchanges, Ecological Modelling, 222: 1038-1047.

Adkinson, A.C. and Humphreys, E.R. 2010. The response of carbon dioxide exchangeto manipulations of Sphagnum water content in an ombrotrophic bog.  Ecohydrology. doi: 10.1002/eco.171.

Dimitrov, D.D., Grant, R.F., Lafleur, P.M., and Humphreys, E.R.  2010.  Modeling the subsurface hydrology of Mer Bleue bog.  Soil Science Society of America Journal, 74: 680-694.

Dimitrov, D.D., Grant, R.F., Lafleur, PM., and Humphreys, E.R.  2010. Modeling peat thermal regime of an ombrotrophic peat land with hummock-hollow microtopography.  Soil Science Society of America Journal, 74: 1406-1425.

St-Hilaire, F., Wu, J., Roulet, N.T., Frolking, S, Lafleur, P.M., Humphreys, E.R., and Arora, V. 2010.  McGill wetland model: evaluation of a peatland carbon simulator developed for global assessments.  Biogeosciences, 7: 3517-3530.

Teklemariam, T.A., Lafleur, P.M., Moore, T.R., Roulet, N.T., and Humphreys, E.R.  2010.  The direct and indirect effects of inter-annual meteorological variability on ecosystem carbon dioxide exchange at a temperate ombrotrophic bog.  Agricultural and Forest Meteorology, 150: 1402-1411.

Wilson, K. S. and Humphreys, E.R. 2010.  Carbon dioxide and methane fluxes from arctic mudboils.  Canadian Journal of Soil Science, 90: 441-449