Marney Isaac , Associate Professor


Home Campus:
U of T Scarborough

University of Toronto

Other Degrees:
MSc University of Guelph
BSc University of Guelph

Honours & Awards:
Canada Research Chair

Contact Information:

Phone:    (416) 287-7276
Location: EV462 (UTSC)
Location: SSH5021 (St. George)

Personal Website:

Research Interests:

  • Agroecology
  • Plant-soil interactions
  • Biogeochemical cycling
  • Environment and development
  • Social-ecological systems
  • Agrarian resource networks
  • Temperate and tropical agroforestry

Teaching This Academic Year:

EESB05: Principles of Soil Science
IDSB02: Environment and Development
EES1128: Biophysical Interactions in Managed Environments

Selected Publications:

Refereed Articles

  • Martin, A.R.and M.E. Isaac. 2015. Plant functional traits in agroecosystems: a blueprint for research. Journal of Applied Ecology 52: 1425-1435.
  • Nasielski, J., J. Furze, J. Tan, A. Bargaz, N.V. Thevathasan and M.E. Isaac. 2015. Agroforestry promotes soybean yield stability and N2-fixation under water stress. Agronomy for Sustainable Development 35: 1541-1549.
  • Fitzpatrick, C.R., A.A. Agrawal, N. Basiliko, A.P. Hastings, M.E. Isaac, M. Preston and M.T.J. Johnson. 2015. The importance of plant genotype and contemporary evolution for terrestrial ecosystem processes. Ecology 96: 2632–2642.
  • Munroe, J.W., G. Soto, E. de M. Virginio Filho, R. Fulthorpe and M.E. Isaac. 2015. Soil microbial and nutrient properties in the rhizosphere of coffee under agroforestry management. Applied Soil Ecology 93: 40-46.
  • Link, C., N.V. Thevathasan, A.M. Gordon and M.E. Isaac. 2015. Determining tree water acquisition zones with stable isotopes in a temperate tree-based intercropping system. Agroforestry Systems 89: 611-620.
  • Gagliardi, S., A.R. Martin, E. de M. Virginio Filho, B. Rapidel and M.E. Isaac. 2015. Intraspecific leaf economic trait variation partially explains coffee performance across agroforestry management regimes. Agriculture, Ecosystems and Environment, 200: 151–160.
  • Borden, K.A., M.E. Isaac, N.V. Thevathasan, A.M. Gordon and S.C. Thomas. 2014. Estimating coarse root biomass with ground penetrating radar in a tree-based intercropping system. Agroforestry Systems 88: 657-669.
  • Isaac, M.E., L.C.N. Anglaaere, D.S, Akoto and E. Dawoe. 2014. Migrant farmers as information brokers: agroecosystem management in the transition zone of Ghana. Ecology and Society 19(2): 56.
  • Isaac, M.E., L.C.N. Anglaaere, K. Borden and S. Adu-Bredu. 2014. Intraspecific root plasticity in agroforestry systems across edaphic conditions. Agriculture, Ecosystems and Environment 185: 16-23.
  • Munroe, J.W. and M.E. Isaac. 2014. Rates and transfer of fixed N in woody perennial agroforestry systems: a review. Agronomy for Sustainable Development 34: 417–427.
  • Isaac, M.E., G. Carlsson, C. Ghoulam, M. Makhani, N.V. Thevathasan and A. Gordon. 2014. Legume performance and nitrogen acquisition strategies in a tree-based agroecosystem. Agroecology and Sustainable Food Systems 38: 686–703.
  • Makhani, M. and M.E. Isaac. 2014. Rhizosphere soil dynamics under nitrogen-induced root modification: the interaction of phosphorus and calcium. Journal of Plant Nutrition and Soil Science 177: 624-632.
  • Isaac, M.E. and L.C.N Anglaaere. 2013. An in-situ approach to detect tree root ecology: Linking ground penetrating radar imaging to isotope derived water acquisition zones. Ecology and Evolution 3: 1330-1339.
  • Whitehead, M. and M.E. Isaac. 2012. Effects of shade on nitrogen and phosphorus acquisition in cereal-legume intercropping systems. Special Issue: Soil biology and its importance to soil fertility. Agriculture 2: 12-24.
  • Isaac, M.E., P. Hinsinger and J.M. Harmand. 2012. Nitrogen and phosphorus economy of a legume tree-cereal intercropping system under controlled conditions. Science of the Total Environment 434: 71-78.
  • Isaac, M.E. 2012. Agricultural information exchange and organizational ties: the effect of network topology on managing agrodiversity. Agricultural Systems 109: 9-15.
  • Dawoe, E., S.J. Quashie-Sam, M.E. Isaac, and S.K. Oppong. 2012. Exploring farmers local knowledge and perceptions of soil fertility and management in the Ashanti Region of Ghana. Geoderma 179-180: 96-103.
  • Djomo, A.N., G. Gravenhorst, A. Kimaro and M.E. Isaac. 2012. Modelling stand dynamics after selective logging: implications for REDD and carbon pool estimations from forest degradation. Journal of Life Sciences 6: 801-816.
  • Isaac, M.E. and Kimaro, A.A. 2011. Diagnosis of nutrient imbalances with vector analysis in agroforestry systems. Journal of Environmental Quality 40: 1-7.
  • Isaac, M.E., Harmand, J.M., Lesueur, D. and Lelon, J. 2011. Tree age and soil phosphorus conditions influence N2-fixation rates and soil N dynamics in natural populations of Acacia senegal. Forest Ecology and Management 261: 582-588.
  • Isaac, M.E., J.M. Harmand and J.J. Drevon. 2011. Growth and nitrogen response of Acacia senegal seedlings to exponential phosphorus additions. Journal of Plant Physiology 168: 776-781.
  • Isaac, M.E., E. Adjei, R. Issaka and V.R. Timmer. 2011. Strategies for improved tree-perennial crop productivity: exponential nutrient loading and cocoa-shade interactions Agroforestry Systems 81: 147-155.
  • Isaac, M.E, A.A. Kimaro, Y. Teng and V.R. Timmer. 2010. Increasing agricultural complexity: An approach for integration of trees in crop landscapes. Special Issue: The role of complex agroecosystems in climate change mitigation. The Open Agricultural Journal 4: 64-71.
  • Dawoe, E., M.E. Isaac and S.J. Quashie-Sam. 2010. Litterfall dynamics in cocoaagroforestry systems of lowland Ghana. Plant and Soil 330: 55-64.
  • Isaac, M.E. and E. Dawoe. 2009. Promoting long-term farm diversity: Integrative management of cocoa agroforestry systems in Ghana. Journal of Science and Technology (Ghana) 26: 26-33.
  • Isaac, M.E., E. Dawoe and K. Sieciechowicz. 2009. Assessing localized knowledge use in agroforestry management with cognitive maps. Environmental Management 43: 1321-1329.
  • Isaac, M.E., B. Erickson, S.J. Quashie-Sam and V.R. Timmer. 2007c. Transfer of knowledge on agroforestry management practices: the structure of informal advice networks. Ecology and Society 12(2): 32.
  • Isaac, M.E., F. Ulzen-Appiah, V.R. Timmer and S.J. Quashie-Sam. 2007b. Early Growth and nutritional response to resource competition in cocoa-shade intercropped systems. Plant and Soil 298: 243-254.
  • Isaac, M.E., V.R. Timmer and S.J. Quashie-Sam. 2007a. Shade tree effects in an 8-year-old cocoa agroforestry system: Biomass and nutrient diagnosis of Theobroma cacao by vector analysis. Nutrient Cycling in Agroecosystems 78: 155-165.
  • Isaac, M.E. and V.R. Timmer. 2007. Comparing in situ methods for measuring nitrogen mineralization under mock precipitation regimes. Canadian Journal of Soil Science 87: 39-42.
  • Isaac, M.E., A.M. Gordon, N. Thevathasan, S.K. Oppong and S.J. Quashie-Sam. 2005. Temporal changes in soil carbon and nitrogen dynamics in tropical multistrata agroforestry systems: a chronosequence of pools and fluxes. Agroforestry Systems 65: 23-31.

Book Chapters

  • Isaac, M.E. and Dawoe, E. 2011. Agrarian communication networks: Consequences for agroforestry. In Ö. Bodin and C. Prell, (eds.) Social Networks and Natural Resource Management: Uncovering the Social Fabric of Environmental Governance. Cambridge University Press, Cambridge. pp. 322-344
  • Kimaro, A.A., M.E, Isaac. and S.O.A. Chamshama. 2011. Carbon pools in tree biomass and soils under rotational woodlot systems in Eastern Tanzania. In Kumar, B.M. and Nair, P.K.R. (eds.) Carbon sequestration Potential in Agroforestry Systems: Marney E. Isaac Opportunities and Challenges. Advances in Agronomy, Vol. 8. Springer, Netherlands. pp.129-143