The green roof team
Dr. Youbin Zheng, Ph.D., MPhil., MSc., BSc.
Dr. Zheng, Environmental Horticulture Chair of the University of Guelph and Vineland
Research and Innovation Centre, is the principle investigator (PI) and founder of the
Guelph Green Roof Research Program. The objectives of his research program are to develop
technologies for producing plant materials in a sustainable and environmentally friendly
manner; to develop and use horticultural technologies for improving our environment and
to help build a sustainable society. He has more than 20 years’ experience in horticulture
research, specifically in green roof technology, greenhouse and nursery plant production,
and urban agriculture. Dr. Zheng’s expertise includes soil science, growing substrates,
irrigation and irrigation water treatment, plant nutrition and fertilization, supplemental
lighting, plant physiology, plant-environment interactions and other sustainable plant
production related technologies.
For more information about Dr. Zheng's research, please click:
Dr Mike Dixon, Ph.D.
Dr. Dixon is a co-PI of the green roof research program, the director of the Controlled Environment
Systems Research Facility (CESRF) and program at the University of Guelph, and was the chair of the
Department of Environmental Biology from 2003-2008. As project leader for the Canadian research team
investigating the contributions of plants to life support in space, Dr. Dixon formed the Space and
Advanced Life Support Agriculture program at the University of Guelph. This program currently represents
Canada's prime contribution to the international space science objectives in life support and the
Controlled Environment Systems Research Facility (CESRF) currently leads the world in technology
developments and research dedicated to studying plant and microbial interactions in advanced life
support systems. Dr. Dixon is also the project leader for the research team at Guelph investigating
the biofiltration of indoor air as a method of alleviating what is commonly known as "sick building syndrome".
Greg Yuristy, MSc., BSc., Research Associate
Mr. Yuristy began researching green roofs in 2009 beginning as a graduate student under Dr. Zheng.
Greg is specialized in green roof growing substrates, green roof growing systems, general roofing
systems as well as green roof plant production technologies. Greg has had a lifelong interest in
green building technologies and over a decade of construction and construction management experience.
Although he is an enthusiastic student of all things green roof related, his primary focus is directed
towards increasing green roof performance through innovation and science.
Katie Vinson, Technician
Ms. Vinson is specialized in the following areas:
After obtaining an undergraduate degree, majoring in Plant Biology, Katie started to work on
green roof and other horticulture plant production research in the School of Environmental
Sciences at the University of Guelph. Katie works toward finding a wider selection of plant
species that can be used in green roof projects. These plants are not only easy to grow and
maintain, but are also fairly familiar to the general public, thus helping to increase the popularity
of green roofs. The goal is to find many plants and plant combinations which are suitable for
growing on green roofs in northern climates. This will then help green roofs in these regions
become more successful, especially long-term, and will facilitate the continuous expansion of the
green roof industry.
- Plant biology
- Plant maintenance
Mary Jane Clark, M.Sc. Horticulturist
Specializes in the following areas:
Mary Jane grew up on a farm and has always been interested in gardening and growing
plants. She enhanced this interest while studying at the University of Guelph (BSc.
Plant Biology, MSc. Horticulture), specifically while studying pollination systems in
fireweed and drought tolerance and breeding of Aquilegia. Mary Jane is now pleased to
be working with the Green Roofs for Northern Climates research team at the University of
Guelph, developing fertilizer and irrigation recommendations for green roof systems.
- Green Roof fertilization
- Green Roof irrigation
- Plant biology
- Landscape design
Tyson S. Jennett, M.Sc.
Tyson completed a B.Sc. in Environmental Science studying Environmental Monitoring
and Analysis. In 2011 he completed a M.Sc. in Land Resource Science with a specialization
in Toxicology, followed by two years as a research associate in the laboratory of Beverley
Hale at the University of Guelph. In 2014 he returned to the University of Guelph to begin
a Ph.D. with Dr. Youbin Zheng. His current research involves the physical and chemical
characterization of green roof substrate components using potentiometric titration,
specific surface analysis, batch adsorption experiments, and soil modeling to optimize
physical and chemical characteristics of blended substrates. His goals include the
development of substrates that show good growing characteristics for plants, as well as
high water and nutrient retention, with an emphasis on reducing phosphorus pollution in runoff.
Former green roof team members
Linping Wang M.Sc. Plant Biologist and Horticulturist
Ms Wang is specialized in the following areas:
- Plant production
- Soil, water analysis
Dr. Lynn (Xiuling) Tian Plant Pathologist
Dr. Tian is specialized in the following areas:
- Plant pathogen
- Using beneficial microorganisms for pathogen control
- Utilizing pathogen suppression properties of certain growing substrate for sustainable pathogen control
Siobhan is an undergraduate student majoring in Earth and Atmospheric Sciences.
She developed an interest in soil sciences early in her university career and has
since expanded this interest to soil-plant relationships in production. She is excited
to be involved in the Green Roof Research Program, and plans to enhance her understanding
of green roofs and relevant production technology while contributing to the research. For
the future, Siobhan hopes to focus on sustainable and efficient plant production, particularly
in an urban context.
University of Guelph, Bovey Building,
50 Stone Road East, Guelph, ON, N1G 2W1