Gedalof, Ze´ev

Dr. Ze'ev Gedalof
Associate Professor
PhD, University of Washington, 2003
519 824-4120 ext. 58083

Physical geography, paleoecology, biogeography, dendrochronology.

My research addresses a range of problems related to forest ecosystem dynamics, climatic variability, and natural resources management. My research approach incorporates a broad spectrum of tools and techniques, but most of my ongoing projects involve the analysis of tree-rings in order to reconstruct past patterns of stand development, disturbance, and climate. I am especially interested in understanding the processes that have caused recent changes in the position of mid-latitude treelines – both in mountain environments, and in temperate savannahs.

GEOG*2110 Climate and the Biophysical Environment
GEOG*2460 Analysis in Geography
GEOG*3110 Biotic and Natural Resources
GEOG*4690 Geography Field Research
GEOG*6330 Biotic Processes & Biophysical Systems

Ecology of Garry oak savannahs in southwestern British Columbia

A range of proxy records (tree-rings, historical documents and photographs, pollen, and sediment accumulation) are being collected to characterize the environmental history of Garry oak meadows in southwestern British Columbia. This information will be used to guide management and ecological restoration within the newly established Gulf Islands National Park Reserve. Key questions I am researching include:

  • Why is Garry oak failing to reproduce at most sites?
  • How have introduced grasses influenced competitive interactions in Garry oak ecosystems?
  • What is the historical fire regime of Garry oak savannahs and woodlands?
  • What is the role of fire in Garry oak associated ecosystems with strong edaphic controls?
  • Why are Garry oak savannahs being encroached by conifers?

This research is being undertaken in collaboration with Marlow Pellatt (Parks Canada), and Dan Smith (University of Victoria Tree-Ring Laboratory).

Interaction between defoliating insects, wildfire, and climatic variability in forests of the British Columbia central interior.

Tree-ring techniques are being used to reconstruct stand histories throughout the interior Douglas-fir zone of British Columbia. Age structure and fire scars are being used to reconstruct stand history. Patterns of annual radial growth within and between stands and species are being used to reconstruct histories of drought and disturbance. Downscaled output from a regional climate model will be used to incorporate these results into spatially explicit models of climate-disturbance-species interactions for the purpose of assessing impacts of future climate scenarios on stand development processes. This research is being undertaken in collaboration with Dan Smith (University of Victoria Tree-Ring Laboratory) and André Arsenault (Interior Forest Region, British Columbia Ministry of Forests).

Course woody debris dynamics in southwestern Ontario

Riparian Ecosystems Woody debris plays an essential role in riparian systems, influencing stream hydrology, geomorphology, and ecology. Yet surprisingly little is known about the long-term dynamics of woody debris cycling, or how land-use change may have affected woody debris dynamics. Unresolved questions include:

  • What are the functions of woody debris in Southwestern Ontario river systems?
  • What was the structure and composition of riparian forests at the time of European contact?
  • How has the structure and composition of woody debris changed since European contact?
  • What are the characteristic residence times of woody debris in Southwestern Ontario rivers?

Gedalof, Z. and J. A. Franks (2019). Stand structure and composition affect the drought sensitivity of Oregon white oak (Quercus garryana Douglas ex Hook.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Forests 10: 381.

Hessburg, P. F., C. Miller, S. A. Parks, N. A. Povak, A. H. Taylor, P. E. Higuera, S. J. Prichard, M. P. North, B. M. Collins, M. D. Hurteau, A. J. Larson, C. D. Allen, S. L. Stephens, H. Rivera-Huerta, C. S. Stevens-Rumann, L. D. Daniels, Z. Gedalof, R. W. Gray, V. R. Kane, D. J. Churchill, R. K. Hagmann, T. A. Spies, C. A. Cansler, R. T. Belote, T. T. Veblen, M. A. Battaglia, C. Hoffman, C. N. Skinner, H. D. Safford and R. B. Salter (2019). Climate, environment, and disturbance history govern resilience of western North American forests. Frontiers in Ecology and Evolution 7: doi: 10.3389/fevo.2019.00239.

Büntgen, U., L. Wacker, J. D. Galván, S. Arnold, D. Arseneault, M. Baillie, J. Beer, M. Bernabei, N. Bleicher, G. Boswijk, A. Bräuning, M. Carrer, F. C. Ljungqvist, P. Cherubini, M. Christl, D. A. Christie, P. W. Clark, E. R. Cook, R. D’Arrigo, N. Davi, Ó. Eggertsson, J. Esper, A. M. Fowler, Z. E. Gedalof, F. Gennaretti, J. Grießinger, H. Grissino-Mayer, H. Grudd, B. E. Gunnarson, R. Hantemirov, F. Herzig, A. Hessl, K.-U. Heussner, A. J. T. Jull, V. Kukarskih, A. Kirdyanov, T. Kolár, P. J. Krusic, T. Kyncl, A. Lara, C. LeQuesne, H. W. Linderholm, N. J. Loader, B. Luckman, F. Miyake, V. S. Myglan, K. Nicolussi, C. Oppenheimer, J. Palmer, I. Panyushkina, N. Pederson, M. Rybnícek, F. H. Schweingruber, A. Seim, M. Sigl, O. C. (Sidorova), J. H. Speer, H.-A. Synal, W. Tegel, K. Treydte, R. Villalba, G. Wiles, R. Wilson, L. J. Winship, J. Wunder, B. Yang and G. H. F. Young (2018). Tree rings reveal globally coherent signature of cosmogenic radiocarbon events in 774 and 993 CE. Nature Communications 9:3605: DOI: 10.1038/s41467-41018-06036-41460.

Chavardès, R. D., L. D. Daniels, Z. Gedalof and D. W. Andison (2018). Human influences superseded climate to disrupt the 20th century fire regime in Jasper National Park, Canada. Dendrochronologia 48: 10-19.

Davis, E. L. and Z. Gedalof (2018). Limited prospects for future alpine treeline advance in the Canadian Rocky Mountains. Global Change Biology: DOI: 10.1111/gcb.14338.

Davis, E. L., H. A. Hager and Z. Gedalof (2018). Soil properties as constraints to seedling regeneration beyond alpine treelines in the Canadian Rocky Mountains. Arctic, Antarctic, and Alpine Research 50: DOI: 10.1080/15230430.15232017.11415625.

Evans, P., E. L. Davis, Z. Gedalof and C. D. Brown (2018). Small herbivore exclosure cages alter microclimate conditions. Forest Ecology and Management 415–416: 118-128.

McInnes, A., E. Fraser, Z. Gedalof and J. Silver (2017). A quantitative analysis of food movement convergence in four Canadian provinces. Agriculture and Human Values 2017: 787–804.

Mayor, J.R., N.J. Sanders, A.T. Classen, R.D. Bardgett, J.-C. Clément, A. Fajardo, S. Lavorel, M.K. Sundqvist, M. Bahn, C. Chisholm, E. Cieraad, Z. Gedalof, K. Grigulis, G. Kudo, D.L. Oberski and D.A. Wardle (2017). Elevation alters ecosystem properties across temperate treelines globally. Nature 542: 91–95, doi:10.1038/nature21027.

Dalgarno, S., J.E. Mersey, Z. Gedalof and L. M (2017). Species-environment associations and predicted distribution of Black Oystercatcher breeding pairs in Haida Gwaii, British Columbia, Canada. Avian Conservation and Ecology 12(2): 9.

McInnes, A., E. Fraser, Z. Gedalof and J. Silver (2017). A quantitative analysis of food movement convergence in four Canadian provinces. Agriculture and Human Values 2017: 787–804.

Mayor, J.R., N.J. Sanders, A.T. Classen, R.D. Bardgett, J.-C. Clément, A. Fajardo, S. Lavorel, M.K. Sundqvist, M. Bahn, C. Chisholm, E. Cieraad, Z. Gedalof, K. Grigulis, G. Kudo, D.L. Oberski and D.A. Wardle (2017). Elevation alters ecosystem properties across temperate treelines globally. Nature 542: 91–95, doi:10.1038/nature21027.

Stretch, V., Z. Gedalof, J. Cockburn and M.F.J. Pisaric (2016). Sensitivity of reconstructed fire histories to detection criteria in mixed-severity landscapes. Forest Ecology and Management 379: 61-69.

Hook, B.A., J. Halfar, J. Bollmann, Z. Gedalof, M.A. Rahman, J. Reyes and D.J. Schulze (2015). Extraction of α-cellulose from mummified wood for stable isotopic analysis. Chemical Geology 405: 19-27.

Hook, B.A., J. Halfar, Z. Gedalof, J. Bollmann and D.J. Schulze (2015). Stable isotope paleoclimatology of the earliest Eocene using kimberlite-hosted mummified wood from the Canadian Subarctic. Biogeosciences 12: 5899-5914, doi:5810.5194/bg-5812-5899-2015.

Marcoux, H.M., L.D. Daniels, S.E. Gergel, E. Da Silva, Z. Gedalof and P.F. Hessburg (2015). Differentiating mixed- and high-severity fire regimes in mixed-conifer forests of the Canadian Cordillera. Forest Ecology and Management 341: 45-58.

Al-Bakri, J.T., L. Brown, Z. Gedalof, A. Berg, W. Nickling, S. Khresat, M. Salahatd and H. Saoub (2014). Modelling desertification risk in the north-west of Jordan using geospatial and remote sensing techniques. Geomatics, Natural Hazards and Risk: DOI:10.1080/19475705.19472014.19945102.

Hager, H.A., S.E. Sinasac, Z. Gedalof and J.A. Newman (2014). Predicting potential global distributions of two Miscanthus grasses: Implications for horticulture, biofuel production, and biological invasions. PLoS ONE 9: doi:10.1371/journal.pone.0100032.

Pellatt, M. G. and Z. Gedalof (2014). Environmental change in Garry oak (Quercus garryana) ecosystems: the evolution of an eco-cultural landscape. Biodiversity and Conservation 23: 2053–2067.

Hook, B., J. Halfar, Z. Gedalof and J. Bollmann (2013). Controlled breaking of mummified wood for use in paleoenvironmental analysis. Tree-Ring Research 69: 87-92.

Newman, J.A., M. Anand, H.A.L. Henry, S. Hunt and Z. Gedalof (2011). Climate Change Biology. Cambridge, CABI.

Wettstein, J.J., J.S. Littell, J.M. Wallace and Z. Gedalof (2011). Coherent region-, species-, and frequency-dependent local climate signals in Northern Hemisphere tree-ring widths. Journal of Climate. 24: 5998-6012.

Bauder, H., B. Belina, D. Butz, Z. Gedalof, A. Lagendijk, P. Mudu, A. Paasi, N. Schuurman and D. Wilson (2009). Critical Practice of Grant Application and Administration: An Intervention. ACME. 9: 102-112.

Falk, D.A., E.K. Heyerdahl, P.M. Brown, T.W. Swetnam, E.K. Sutherland, Z. Gedalof, L. Yocom and T.J. Brown (2010). Fire and climate variation in western North America from fire-scar and tree-ring networks. PAGES. 18: 70-72.

Gedalof, Z. (2011). Climate and Spatial Patterns of Wildfire. The Landscape Ecology of Fire. D. McKenzie, D. Falk and C. Miller, Eds., Springer: 89-116.

Gedalof, Z. and A.A. Berg (2010). Tree ring evidence for a limited direct CO2 fertilization effect. Global Biogeochemical Cycles. 24: GB3027, doi:10.1029/2009GB003699.

Newman, J.A., M. Anand, H.A.L. Henry, S. Hunt and Z. Gedalof (2011). Climate Change Biology. Cambridge, CABI.

Prichard, S.J., Z. Gedalof, W.W. Oswald and D.L. Peterson (2009). Holocene fire and vegetation dynamics in a montane forest, North Cascade Range, Washington, USA. Quaternary Research. 72: 57-67.

Forest Ecology, Climate Change, Wildfire

Please contact me regarding potential graduate student opportunities ( (email address) ). I encourage applications from not only biogeographers, but also individuals with backgrounds in ecology, botany, climatology, forestry, statistics, or other related disciplines.

Graduate Students Supervised

Name Research
M.Sc. 2007 Franks, Jennifer A. Inter- and intraspecific competition in mixed Garry oak and Douglas-fir stands: modelling stand dynamics based on tree ring analysis.
M.Sc. 2007 Maertens, Thomas Brian Climate controls on the growth and distribution of Garry Oak (Quercus Garryana).
M.Sc. 2007 Smith, Shyanne Garry oak savannah dynamics in the Gulf Islands National Park Reserve: pattern and process of forest encroachment.
M.Sc. 2008 Davy, Lesley Soil moisture dynamics in invaded Garry oak savannas.
M.Sc. 2009 Clark, Matthew Graham Reconstruction of southern Ontario's past climate, at an annual resolution, from 2000 years of tree ring proxy.
M.Sc. 2010 DaSilva, Eric Historic Controls of Wildfire in The Joseph-Gold Creek Watershed, British Columbia: Implications of Climate Change and Fire Suppression.
M.Sc. 2011 Mather, Vesta Pre-instrumental climatic variability in the Kootenay Mountains, BC.
M.Sc. 2011 Schutten, Kerry Sensitivity of Sugar Maple to Climatic Change.
M.Sc. 2011 Stretch, Vanessa [M.Sc.] CO² fertilization: Differences between Pseudotsuga menziesii and Pinus ponderosa in their growth responses to elevated CO².
M.Sc. 2013 Brown, Robert Alpine Treeline Dynamics and Climatic Change.
M.Sc. 2014 Dihn, Theresa Influence of human and climatic variability on historic wildfire dynamics in Jasper National Park, Alberta, Canada
M.Sc. 2016 Benakoun, Laura The relationship between long-term folinar decline assessment and annual growth of Sugar Maple in Ontario, Canada.
M.Sc. 2016 Dalgarno, Sebastian Predictive Modelling of the Black Oystercatcher (Haematopus Bachmani) Breeding Pair Occurrence and Prey Abundance in Haida Gwaii, British Columbia..
Ph.D. 2016 Stretch, Vanessa [PhD.] A multiproxy reconstruction of mixed-severity wildfire dynamics in the Foothills of the Rocky Mountains, Alberta, Canada
M.Sc. 2017 Gillam, William Evaluating the Impacts of Agricultural Development on Landscape Scale Ecosystem Stability in a European Context.
Ph.D. 2018 Davis, Emma An evaluation of constraints to treeline advance across multiple scales in the Canadian Rocky Mountains.
Ph.D. 2021 Bonada, Anabela An Evaluation on the Effects of a Changing Climate on the Growth of Mixed Stands of Nothofagus nervosa and Nothofagus obliqua, Along a Precipitation Gradient in Northern Patagonia
M.Sc. 2022 Rewucki, Isabel Exploration of the Spatial and Temporal Variability of Ground Temperature Below and Above Treeline.
M.Sc. 2022 Shay, Emma Effects of subalpine and alpine soil from Vancouver Island, British Columbia, on the germination and growth of Pacific silver fir, mountain hemlock, and yellow cedar in a greenhouse.
M.Sc. 2024 Pashinsky, David An Examination of Competition and Climate Response of Pines (Pinus spp.) and Oaks (Quercus spp.) in Algonquin Provincial Park Using Dendrochronology
M.Sc. inc. Charlton, Nicole K Fire history in the Rice Lake Plains.
M.Sc. inc. Downe, Madison Forest dynamics in the black oak savanna at The Pinery Provincial Park, particularly how herbivory and wildfire influence oak growth and regeneration.