Klironomos Lab - Dept. of Integrative Biology - University of Guelph - Guelph, Ontario, Canada- N1G 2W1 - (519) 824-4120 ext 56718


Jeff Powell (jpowell [at] uoguelph [dot] ca)

Education:

BSc (Honours) - University of Manitoba
MSc - Simon Fraser University
PhD candidate - University of Guelph

Research Interests:

Human activities can have subsequent effects on biodiversity and ecosystem functioning, sometimes at a scale far greater than that within which the activities occur.  This is especially true if these activities are practiced widely.  New and existing technologies must be monitored so that their practices can be modified to prevent or exploit these effects.  I am interested in the effects of these activities on the diversity and functioning of soil biota, and in the roles that soil biota play in mediating or exacerbating the effects of these human activities.  For my dissertation, I am studying the effects that extensive adoption of genetically-modified, herbicide-tolerant cropping systems have on soil food webs and the formation and diversity of arbuscular mycorrhizal symbioses in agricultural systems, with an emphasis on the functional consequences of these effects.

Jeffrey's New Home

 

Curriculum Vitae

 

 

Publications:

 

D.J. Levy-Booth, R.G. Campbell, R.H. Gulden, M.M. Hart, J.R. Powell, J.N. Klironomos, K.P. Pauls, C.J. Swanton, J.T. Trevors, and K.E. Dunfield, 200x, “Cycling of extracellular DNA in the soil environment”, Soil Biology and Biochemistry (accepted 18 June 2007)

 

 

J.R. Powell, 200x, “Linking soil organisms within food webs to ecosystem functioning and environmental change”, Advances in Agronomy 96: (in press)

 

 

 

J.R. Powell, R.H. Gulden, M.M. Hart, R.G. Campbell, D.J. Levy-Booth, K.E. Dunfield, K.P. Pauls, C.J. Swanton, J.T. Trevors, and J.N. Klironomos, 2007 “Mycorrhizal and rhizobial colonization of genetically-modified and conventional soybeans”, Applied and Environmental Microbiology 73: 4365-4367.

 

 

R.H. Gulden, D. Levy-Booth, R. Campbell, J.R. Powell, M.M. Hart, J.T. Trevors, K.P. Pauls, J.N. Klironomos, and C.J. Swanton, 2007, “An empirical approach to absolute target DNA quantification in environmental samples using single polymerase chain reactions”, Soil Biology and Biochemistry 39: 1956-1967.

 

 

J.R. Powell and J.N. Klironomos, 2007, “The ecology of plant-microbial mutualisms”, Chapter 10 in Soil Microbiology, Ecology, and Biochemistry, 3rd ed. (E.A. Paul, Ed.), Academic Press.

 

 

 

J.R. Powell and K.E. Dunfield, 2007, “Non-target impacts of genetically-modified, herbicide-tolerant crops on soil microbial and faunal communities”, pages 127-137 in The First Decade of Herbicide-Resistant Crops in Canada, Topics in Canadian Weed Science, vol. 4 (R.H. Gulden and C.J. Swanton, Eds), Canadian Weed Science Society – Société canadienne de malherbologie: Sainte Anne de Bellevue, QC.

 

 

K.A. Stinson, S.A. Campbell, J.R. Powell, B.E. Wolfe, R.M. Callaway, G.C. Thelen, S.G. Hallett, D. Prati, J.N. Klironomos, 2006, “Invasive plant suppresses the growth of native tree seedlings by disrupting belowground mutualisms”, PLoS Biology 4: 727-731.

 

 

J.N. Klironomos, M.F. Allen, M.C. Rillig, J. Piotrowski, S. Makvandi-Nejad, B.E. Wolfe, and J.R. Powell, 2005, “Abrupt rise in atmospheric CO2 overestimates community response in a model plant-soil system”, Nature 433: 621-624

 

 

R.H. Gulden, S. Lerat, M.M. Hart, J.R. Powell, J.T. Trevors, K.P. Pauls, J.N. Klironomos, and C.J. Swanton, 2005, “Quantitation of transgenic plant DNA in leachate water: real-time PCR analysis”, Journal of Agricultural and Food Chemistry 53: 5858-5865

 

 

J.R. Powell and J.M. Webster, 2004, “Interguild antagonism between biological controls: impact of entomopathogenic nematode application on an aphid predator, Aphidoletes aphidimyza (Diptera: Cecidomyiidae)”, Biological Control 30: 110-118

 

 

 

J.R. Powell and J.M. Webster, 2004, “Target host finding by Steinernema feltiae and Heterorhabditis bacteriophora in the presence of a non-target insect host”, Journal of Nematology 36: 285-289

 

 

 

J.R. Powell, L.C. Graham, and T.D. Galloway, 2003, “Development time of Urolepis rufipes (Hymenoptera: Pteromalidae) and effect of female density on offspring sex ratio and reproductive output”, Proceedings of the Entomological Society of Manitoba 59: 16-20

 

 

 

 

FIG. 1. AM (top panels) and rhizobial (middle and bottom panels) responses to genetically modified and conventional soybean varieties at the R3 (early pod formation; left) and R7 (physiological maturity; right) growth stages. AM colonization was measured as the percentage of root segments colonized by AM fungal hyphal structures. Rhizobial colonization was measured as the number and mass of nodules per root system. Soybean variety was a significant source of variation (P < 0.05) for all graphs except the top right graph. Genetic modification was not a significant source of variation in any case (indicated by Pmod values [i.e., P values for the variable of modification]). Bars and lines represent backtransformed means and standard errors, respectively.