drezner


T.D. Drezner

Photo of T.D. Drezner

Department of Geography

Associate Professor

Office: Ross Building, S408
Phone: (416) 736-2100 Ext: 20511
Email: drezner@yorku.ca

I am a physical geographer with a specialty in plants, plant-climate interactions, and facilitation (where a plant benefits from being located near another plant, such as under its canopy). My primary expertise is in desert ecosystems, though I also work in the Great Lakes region (among other places). I am currently working on several projects, including one with an endangered species of cactus at Point Pelee National Park (Ontario) to assist management with understanding its ecological limits, and aiding the Park’s conservation efforts. I study everything from its interactions with and dependence on other species, to microsite variations across its range. I also have active research in the Desert Southwest (Arizona, USA) looking at cactus demographics, facilitation, and responses to climate. Past work includes discovering that cacti may have greater establishment after volcanic eruptions, due to the temporary changes in climate that occur globally. For example, some Arizona cactus populations have many cacti that established around 1883 when Krakatau erupted in Indonesia.

Degrees

Ph.D. (Geography), Arizona State University
M.A.(Geography), Arizona State University
B.A.(Geography), California State University, Fullerton

Research Interests

, Deserts and Arid Lands, Plant-Climate Interactions, Disturbance and Invasion, Biogeography
Journal Articles

Publication
Year

Drezner, T.D. 2017. Shade, reproductive effort and growth of the endangered native cactus, Opuntia humifusa, in Point Pelee National Park, Canada. Journal of the Torrey Botanical Society. 144:179-190.

2017

Drezner, T.D. 2017. North and south: morphological variability in the endangered Opuntia cespitosa in Canada and variation with environmental conditions. Castanea. 82: 8-23.

2017

Drezner, T.D. 2016. Testing the validity of age-size reconstructions in cohort species, using Carnegiea gigantea. Journal of the Arizona-Nevada Academy of Science. 47: 23-27

2016

Drezner, T.D., Drezner, Z., Balakrishnan, N. 2015. Estimating the transition of individuals between life stages. Environmetrics. 26: 526-533.

2015

Dinh, T. Hewitt N., and Drezner, T.D. 2015. Fire history reconstruction in the black oak (Quercus velutina) savanna of High Park, Toronto. Natural Areas Journal. 35(3): 468-475.

2015

Drezner, T.D. 2015. Regional environmental conditions affect microsite response in a keystone desert species. Journal of Arid Environments. 116: 89-95.

2015

Gorelick, R., Drezner, T.D., Hancock, K. 2015. Freeze-tolerance of cacti (Cactaceae) in Ottawa, Ontario, Canada. Madroño 62: 33-45.

2015

Drezner, T.D. 2014. The keystone saguaro (Carnegiea gigantea, Cactaceae): a review of its ecology, associations, reproduction, limits, and demographics. Braun-Blanquet invited review. Plant Ecology. 215: 581-595.

2014

Danzer S. and Drezner, T.D. 2014. Relationships between epidermal browning, girdling, damage, and bird cavities in a military restricted database of 12,000+ plants of the keystone Carnegiea gigantea in the northern Sonoran Desert. Madroño. 61: 115-125.

2014

Drezner, T.D. 2014. How long does the giant saguaro live? Life, death and reproduction in the desert. Journal of Arid Environments. 104: 34-37.

2014

Fall, P.L. and Drezner, T.D. 2013. Species origins, dispersal, and island vegetation dynamics in the South Pacific. Annals of the Association of American Geographers. 103: 1041-1057.

2013

Drezner, T.D. 2013. The paradoxical distribution of a shallow-rooted keystone species away from surface water, near the water-limited edge of its range in the Sonoran Desert: Seed-seedling conflicts. Acta Oecologica. 47: 81-84.

2013

Medeiros, A.S. and Drezner, T.D. 2012. Vegetation, climate, and soil relationships across the Sonoran Desert. Ecoscience. 19(2): 148-160.

2012

Donnermeyer, C.J. and Drezner, T.D. 2012. Cohort establishment on slopes: growth rates, demographic patterns, and the relationship to volcanic eruptions. Journal of Arid Environments. 76: 133-137.

2012

Drezner, T.D. 2011. Cactus surface temperatures are impacted by seasonality, spines and height on plant. Environmental and Experimental Botany. 74: 17-21.

2011

Lam, D.K., Remmel, T.K., and Drezner, T.D. 2011. Tracking desertification in California using remote sensing: a sand dune encroachment approach. Remote Sensing. 3: 1-13.

2011

Fall, P.L. and Drezner, T.D. 2011. Plant dispersal, introduced species, and vegetation change in the South Pacific Kingdom of Tonga. Pacific Science. 65(2): 143-156.

2011

Danzer, S. and Drezner, T.D. 2010. Demographics of more than 12,000 individuals of a keystone species in the northern Sonoran Desert since the mid-1800s. International Journal of Plant Sciences. 171(5): 538-546.

2010

Drezner, T.D. and Balling, R.C. Jr. 2008. Regeneration cycles of the keystone species Carnegiea gigantea are linked to worldwide volcanism. Journal of Vegetation Science 19: 587-596

2008

Drezner, T.D. 2008. Variation in age and height of onset of reproduction in the saguaro cactus (Carnegiea gigantea) in the Sonoran Desert. Plant Ecology. 194: 223-229.

2008

Drezner, T.D. and Lazarus, B.L. 2008. The population dynamics of columnar and other cacti: a review. Invited to Geography Compass. 2: 1-29.

2008

Fall, P.L., Drezner, T.D., and Franklin, J. 2007. Dispersal ecology of the lowland rain forest in the Vava’u Island Group, Kingdom of Tonga. New Zealand Journal of Botany. 45: 393-417.

2007

Drezner, T.D. 2007. An analysis of winter temperature and dew point under the canopy of a common Sonoran Desert nurse and the implications for positive plant interactions. Journal of Arid Environments. 69: 554-568.

2007

Tenorio, R.C. and Drezner, T.D. 2006. Native and invasive vegetation of karst springs in Wisconsin’s Driftless Area. Hydrobiologia. 568: 499-505.

2006

Drezner, T.D. 2006. The regeneration of a protected Sonoran Desert cactus since 1800 A.D. over 50,000 km2 of its range. Plant Ecology. 183: 171-176.

2006

Drezner, T.D. 2006. Regeneration of Carnegiea gigantea (Cactaceae) since 1850 in three populations in the northern Sonoran Desert. Acta Oecologica. 29: 178-186.

2006

Drezner, T.D. 2006. Plant facilitation in extreme environments: the non-random distribution of saguaro cacti (Carnegiea gigantea) under their nurse associates and the relationship to nurse architecture. Journal of Arid Environments. 65: 46-61.

2006

Drezner, T.D. 2005. Saguaro (Carnegiea gigantea, Cactaceae) growth rate over its American range and the link to summer precipitation. Southwestern Naturalist. 50(1): 65-68.

2005

Drezner, T.D. 2004. Few native species colonize on mud flats ten years after dam removal (Wisconsin). Ecological Restoration. 22(1): 50-51.

2004

Drezner, T.D. 2003. A test of the relationship between seasonal rainfall and saguaro cacti branching patterns. Ecography. 26(4): 393-404.

2003

Drezner, T.D. 2003. Saguaro (Carnegiea gigantea, Cactaceae) age-height relationships and growth: the development of a general growth curve. American Journal of Botany. 90(6): 911-914.

2003

Drezner, T.D., and Garrity, C.M. 2003. Saguaro distribution under nurse plants in Arizona's Sonoran Desert: directional and microclimate influences. Professional Geographer. 55(4): 505-512.

2003

Drezner, T.D. 2003. Revisiting Bergmann's Rule for saguaros (Carnegiea gigantea (Engelm.) Britt. and Rose): stem diameter patterns over space. Journal of Biogeography. 30: 353-359.

2003

Drezner, T.D. 2003. Regional- and local-scale variations in plant distribution in the Sonoran Desert. Madroño. 50(2): 122-125.

2003

Drezner, T.D. and Balling, R.C. Jr. 2002. Climatic controls of saguaro (Carnegiea gigantea) regeneration: a potential link with El Niño. Physical Geography. 23(6): 465-475.

2002

Drezner, T.D., Fall, P.L., and Stromberg, J.C. 2001. Plant distribution and dispersal mechanisms at the Hassayampa River Preserve, Arizona, U.S.A. Global Ecology and Biogeography. 10: 205-217.

2001

Approach to Teaching


In 2015 I was honoured to receive the Department's UNDERGRADUATE TEACHING AWARD, as selected by students. I teach a variety of classes, including -Physical Geography (1400) -Intro to Statistics (2420) -Disaster! The Earth's Extreme Natural Events (3700) -Desert Ecosystems (4410) -Seminar in Physical Geography (graduate class, 5600) and irregularly -Biogeography (3500) -Physical Geography of the City (3900)


Current Courses

Term Course Number Section Title Type
Fall/Winter 2020 EU/GEOG1400 6.0 A Physical Geography LECT


Upcoming Courses

Term Course Number Section Title Type
Winter 2021 EU/GEOG3700 3.0 M Disaster! Earth's Extreme Events LECT
Winter 2021 EU/GEOG2420 3.0 M Intro. Stats Analysis in Geography LECT
Fall/Winter 2020 EU/GEOG1400 6.0 A Physical Geography LECT

I am a physical geographer with a specialty in plants, plant-climate interactions, and facilitation (where a plant benefits from being located near another plant, such as under its canopy). My primary expertise is in desert ecosystems, though I also work in the Great Lakes region (among other places). I am currently working on several projects, including one with an endangered species of cactus at Point Pelee National Park (Ontario) to assist management with understanding its ecological limits, and aiding the Park’s conservation efforts. I study everything from its interactions with and dependence on other species, to microsite variations across its range. I also have active research in the Desert Southwest (Arizona, USA) looking at cactus demographics, facilitation, and responses to climate. Past work includes discovering that cacti may have greater establishment after volcanic eruptions, due to the temporary changes in climate that occur globally. For example, some Arizona cactus populations have many cacti that established around 1883 when Krakatau erupted in Indonesia.

Degrees

Ph.D. (Geography), Arizona State University
M.A.(Geography), Arizona State University
B.A.(Geography), California State University, Fullerton

Research Interests

, Deserts and Arid Lands, Plant-Climate Interactions, Disturbance and Invasion, Biogeography

All Publications


Journal Articles

Publication
Year

Drezner, T.D. 2017. Shade, reproductive effort and growth of the endangered native cactus, Opuntia humifusa, in Point Pelee National Park, Canada. Journal of the Torrey Botanical Society. 144:179-190.

2017

Drezner, T.D. 2017. North and south: morphological variability in the endangered Opuntia cespitosa in Canada and variation with environmental conditions. Castanea. 82: 8-23.

2017

Drezner, T.D. 2016. Testing the validity of age-size reconstructions in cohort species, using Carnegiea gigantea. Journal of the Arizona-Nevada Academy of Science. 47: 23-27

2016

Drezner, T.D., Drezner, Z., Balakrishnan, N. 2015. Estimating the transition of individuals between life stages. Environmetrics. 26: 526-533.

2015

Dinh, T. Hewitt N., and Drezner, T.D. 2015. Fire history reconstruction in the black oak (Quercus velutina) savanna of High Park, Toronto. Natural Areas Journal. 35(3): 468-475.

2015

Drezner, T.D. 2015. Regional environmental conditions affect microsite response in a keystone desert species. Journal of Arid Environments. 116: 89-95.

2015

Gorelick, R., Drezner, T.D., Hancock, K. 2015. Freeze-tolerance of cacti (Cactaceae) in Ottawa, Ontario, Canada. Madroño 62: 33-45.

2015

Drezner, T.D. 2014. The keystone saguaro (Carnegiea gigantea, Cactaceae): a review of its ecology, associations, reproduction, limits, and demographics. Braun-Blanquet invited review. Plant Ecology. 215: 581-595.

2014

Danzer S. and Drezner, T.D. 2014. Relationships between epidermal browning, girdling, damage, and bird cavities in a military restricted database of 12,000+ plants of the keystone Carnegiea gigantea in the northern Sonoran Desert. Madroño. 61: 115-125.

2014

Drezner, T.D. 2014. How long does the giant saguaro live? Life, death and reproduction in the desert. Journal of Arid Environments. 104: 34-37.

2014

Fall, P.L. and Drezner, T.D. 2013. Species origins, dispersal, and island vegetation dynamics in the South Pacific. Annals of the Association of American Geographers. 103: 1041-1057.

2013

Drezner, T.D. 2013. The paradoxical distribution of a shallow-rooted keystone species away from surface water, near the water-limited edge of its range in the Sonoran Desert: Seed-seedling conflicts. Acta Oecologica. 47: 81-84.

2013

Medeiros, A.S. and Drezner, T.D. 2012. Vegetation, climate, and soil relationships across the Sonoran Desert. Ecoscience. 19(2): 148-160.

2012

Donnermeyer, C.J. and Drezner, T.D. 2012. Cohort establishment on slopes: growth rates, demographic patterns, and the relationship to volcanic eruptions. Journal of Arid Environments. 76: 133-137.

2012

Drezner, T.D. 2011. Cactus surface temperatures are impacted by seasonality, spines and height on plant. Environmental and Experimental Botany. 74: 17-21.

2011

Lam, D.K., Remmel, T.K., and Drezner, T.D. 2011. Tracking desertification in California using remote sensing: a sand dune encroachment approach. Remote Sensing. 3: 1-13.

2011

Fall, P.L. and Drezner, T.D. 2011. Plant dispersal, introduced species, and vegetation change in the South Pacific Kingdom of Tonga. Pacific Science. 65(2): 143-156.

2011

Danzer, S. and Drezner, T.D. 2010. Demographics of more than 12,000 individuals of a keystone species in the northern Sonoran Desert since the mid-1800s. International Journal of Plant Sciences. 171(5): 538-546.

2010

Drezner, T.D. and Balling, R.C. Jr. 2008. Regeneration cycles of the keystone species Carnegiea gigantea are linked to worldwide volcanism. Journal of Vegetation Science 19: 587-596

2008

Drezner, T.D. 2008. Variation in age and height of onset of reproduction in the saguaro cactus (Carnegiea gigantea) in the Sonoran Desert. Plant Ecology. 194: 223-229.

2008

Drezner, T.D. and Lazarus, B.L. 2008. The population dynamics of columnar and other cacti: a review. Invited to Geography Compass. 2: 1-29.

2008

Fall, P.L., Drezner, T.D., and Franklin, J. 2007. Dispersal ecology of the lowland rain forest in the Vava’u Island Group, Kingdom of Tonga. New Zealand Journal of Botany. 45: 393-417.

2007

Drezner, T.D. 2007. An analysis of winter temperature and dew point under the canopy of a common Sonoran Desert nurse and the implications for positive plant interactions. Journal of Arid Environments. 69: 554-568.

2007

Tenorio, R.C. and Drezner, T.D. 2006. Native and invasive vegetation of karst springs in Wisconsin’s Driftless Area. Hydrobiologia. 568: 499-505.

2006

Drezner, T.D. 2006. The regeneration of a protected Sonoran Desert cactus since 1800 A.D. over 50,000 km2 of its range. Plant Ecology. 183: 171-176.

2006

Drezner, T.D. 2006. Regeneration of Carnegiea gigantea (Cactaceae) since 1850 in three populations in the northern Sonoran Desert. Acta Oecologica. 29: 178-186.

2006

Drezner, T.D. 2006. Plant facilitation in extreme environments: the non-random distribution of saguaro cacti (Carnegiea gigantea) under their nurse associates and the relationship to nurse architecture. Journal of Arid Environments. 65: 46-61.

2006

Drezner, T.D. 2005. Saguaro (Carnegiea gigantea, Cactaceae) growth rate over its American range and the link to summer precipitation. Southwestern Naturalist. 50(1): 65-68.

2005

Drezner, T.D. 2004. Few native species colonize on mud flats ten years after dam removal (Wisconsin). Ecological Restoration. 22(1): 50-51.

2004

Drezner, T.D. 2003. A test of the relationship between seasonal rainfall and saguaro cacti branching patterns. Ecography. 26(4): 393-404.

2003

Drezner, T.D. 2003. Saguaro (Carnegiea gigantea, Cactaceae) age-height relationships and growth: the development of a general growth curve. American Journal of Botany. 90(6): 911-914.

2003

Drezner, T.D., and Garrity, C.M. 2003. Saguaro distribution under nurse plants in Arizona's Sonoran Desert: directional and microclimate influences. Professional Geographer. 55(4): 505-512.

2003

Drezner, T.D. 2003. Revisiting Bergmann's Rule for saguaros (Carnegiea gigantea (Engelm.) Britt. and Rose): stem diameter patterns over space. Journal of Biogeography. 30: 353-359.

2003

Drezner, T.D. 2003. Regional- and local-scale variations in plant distribution in the Sonoran Desert. Madroño. 50(2): 122-125.

2003

Drezner, T.D. and Balling, R.C. Jr. 2002. Climatic controls of saguaro (Carnegiea gigantea) regeneration: a potential link with El Niño. Physical Geography. 23(6): 465-475.

2002

Drezner, T.D., Fall, P.L., and Stromberg, J.C. 2001. Plant distribution and dispersal mechanisms at the Hassayampa River Preserve, Arizona, U.S.A. Global Ecology and Biogeography. 10: 205-217.

2001

Approach to Teaching


In 2015 I was honoured to receive the Department's UNDERGRADUATE TEACHING AWARD, as selected by students. I teach a variety of classes, including -Physical Geography (1400) -Intro to Statistics (2420) -Disaster! The Earth's Extreme Natural Events (3700) -Desert Ecosystems (4410) -Seminar in Physical Geography (graduate class, 5600) and irregularly -Biogeography (3500) -Physical Geography of the City (3900)


Current Courses

Term Course Number Section Title Type
Fall/Winter 2020 EU/GEOG1400 6.0 A Physical Geography LECT


Upcoming Courses

Term Course Number Section Title Type
Winter 2021 EU/GEOG3700 3.0 M Disaster! Earth's Extreme Events LECT
Winter 2021 EU/GEOG2420 3.0 M Intro. Stats Analysis in Geography LECT
Fall/Winter 2020 EU/GEOG1400 6.0 A Physical Geography LECT