Forestry

What's with those colours? Sean Thomas on the science behind this year's fall foliage

Christopher.Sorensen — Fri, 21 Oct 2022 13:01:16 +0000

What's with those colours? Sean Thomas on the science behind this year's fall foliage

Christopher.Sorensen Fri, 10/21/2022 - 09:01

Cutline

(photo by David Lee)

Topic

Forestry

John H. Daniels Faculty of Architecture

Toronto residents are enjoying a particularly dazzling autumn display this year as the city’s tree canopy changes colour amid the cooling temperatures.

That includes the fiery red leaves of the sugar maple that stands on the southeast edge of Spadina Circle near the University of Toronto’s John H. Daniels Faculty of Architecture, Landscape, and Design, where Sean Thomas is a professor of forestry and a longtime associate editor at the journal Tree Physiology.

Thomas says a perfect storm of climatic conditions this season have produced especially vibrant leaf tones.

He recently spoke to Danny Sinopoli about the science behind this year’s eye-catching autumnal foliage.

Why do leaves change colour in the fall? What’s the science behind it?

There is a common misconception that autumnal leaf-colour change is due entirely to degradation of chlorophyll that “unmasks” other pigments that are already there. This is true basically with yellow colouration, which is mainly due to carotenoid pigments. However, red colours in fall foliage are due to newly produced anthocyanin pigments, which raises an intriguing functional biology question: What is the adaptive value in leaves producing new pigments just before the leaves are to be shed?

There are a couple of hypotheses, but the explanation that I think has received the most support is that anthocyanin pigments are playing a role as a “sunscreen” that better enables trees to recover nutrients from senescing leaves. It turns out that the breakdown products of chlorophyll are highly reactive, particularly under high UV exposure and low temperatures. Without the protection offered by anthocyanins, free radicals are generated from the breakdown products of chlorophyll that disrupt the process of nutrient recovery. Some anthocyanins are also antioxidants and scavenge the free radicals, so there are likely two aspects to their protective function during leaf senescence.

This nutrient recovery hypothesis predicts that anthocyanin production should be greatest when temperatures are low – but still above freezing, since frost events kill leaves – and light levels are high. This pattern is widely supported. Demonstrating that anthocyanin production actually increases nutrient recovery itself is more difficult to demonstrate, but there is some evidence for this as well.

So, are the colours actually more vivid this year?

Compared to last year, yes. Consistent with the theory, last fall was a relatively warm one in the GTA, without near-frost events until well into November – and also relatively cloudy conditions. This year had the right combination [for brighter colour] of cold weather events, lack of drought or a hard frost and relatively sunny conditions.

A sugar maple on Spadina Circle puts on a fall show (photo by Zheren Zheng)

Why do people react so strongly to red tones – like those of the sugar maple on Spadina Circle?

I think the accepted psychological theory is that red provokes strong emotional reactions because it is a danger cue. But what happens when the entire landscape is red, or the colour is rendered on such a large scale?

To speculate wildly outside of my area of expertise, a red forest landscape may initially provoke a kind of alarm reaction, to which viewers then acclimate, and this acclimation is pleasantly stimulating. Perhaps this is a bit like spicy food: “Hot” flavours are due to pain receptors, and the relaxation of the pain response releases endorphins.

Researchers study plants sprouting from century-old seeds uncovered during Toronto Port Lands excavation

geoff.vendeville — Mon, 27 Jun 2022 20:23:53 +0000

Researchers study plants sprouting from century-old seeds uncovered during Toronto Port Lands excavation

geoff.vendeville Mon, 06/27/2022 - 16:23

Cutline

Forestry PhD candidate Melanie Sifton examines soil recovered from the Port Lands construction site (photo by Geoffrey Vendeville)

Chris Sasaki

Topic

Breaking Research

Cell and Systems Biology

Cities

Earth Sciences

Ecology & Evolutionary Biology

Forestry

Graduate Students

John H. Daniels Faculty of Architecture

Undergraduate Students

University College

Victoria College

At a Toronto Port Lands construction site on the city’s waterfront, keen-eyed workers recently spotted plants that had sprouted from soil recently exposed by the removal of tonnes of earth. The plants were hard stem bulrush and cattails, which are commonly found in freshwater marshes.

Sarah Finkelstein and Shelby Riskin

Because the plants grew from a patch of ground that had been seven metres below the surface for a century, conservationists concluded that they had grown from seeds buried when Ashbridges Bay Marsh at the mouth of the Don River was covered with landfill in the early 1900s.

Now, a team of U of T researchers including Sarah Finkelstein and Shelby Riskin is studying the soil removed from the site for a better understanding of the long-lost natural habitat.

Finkelstein, a paleontologist and associate professor who is chair of the Faculty of Arts & Science’s department of Earth sciences, studies paleoenvironmental records to better understand past climates and how ecosystems respond to environmental change. Mrinmayee Sengupta, an undergraduate geography student and University College member, will be helping her analyze the Port Lands soil.

“Our first goal is to understand what the marsh looked like back then,” Finkelstein says. “We’ll try to answer questions like: What was the plant community like? What were the food webs like? What role did this marsh play ecologically on a local and regional scale?”

Meanwhile, Riskin, an assistant professor, teaching stream, in the department of ecology and evolutionary biology in the Faculty of Arts & Science, will study how changes in land use impact ecosystems and how those ecosystems can continue to function in the face of change. Stuart Ralston, an undergraduate student studying environmental science and a member of Victoria College, will be working with Riskin on the project.

“We'll look for evidence of the life in the marsh – shells, seeds, pollen – and hopefully get an idea of the biodiversity of those soils from 100 years ago and compare it to what we find in the wetland soils in the area today,” Riskin says.

“I’m quite curious as to what we will find. If there is going to be a viable seed bank of native plants in those soils, or if there’s evidence that it was already a degraded ecosystem 100 years ago.”

Plants sprouted from 100-year-old seeds on a Port Lands construction site (photo courtesy of Waterfront Toronto/Vid Ingelevics/Ryan Walker)

Ashbridges Bay Marsh was once a thriving natural ecosystem. But by the end of the 1800s it was suffering from sewage and pollution from Toronto’s waterfront cattle yards, among other sources. As the city grew in the early 20th century, it was covered over and more industry moved onto the new land.

Today, the Port Lands is undergoing major redevelopment to reduce flooding at the mouth of the Don River and to create parks and new wetlands. As workers dig, they are uncovering the city’s recent history like urban archeologists.

Soil samples from the Port Lands in U of T's Earth Sciences Centre (photo by Geoffrey Vendeville)

The researchers will also measure the carbon content of the soil to understand whether it came from a natural source or human activity, and how well the marsh served to absorb and store carbon.

“Right now, my research group is working a lot on carbon uptake and sequestration in wetlands, which is an important research focus in Ontario given our abundance of wetlands and their potential role in mitigating climate change,” Finkelstein says. “This work could tell us how well this wetland functioned as a carbon sink. It will also help us learn more about wetland restoration and what we may be able to recreate on the Toronto waterfront.”

From watermelons to forest fires, U of T graduate students unpack research in three-minute thesis competition

Christopher.Sorensen — Wed, 27 Apr 2022 15:49:17 +0000

From watermelons to forest fires, U of T graduate students unpack research in three-minute thesis competition

Christopher.Sorensen Wed, 04/27/2022 - 11:49

Cutline

Atefeh Mohammadi took home the top prize in this year's Three Minute Thesis contest for presenting research on using a compound found in watermelons to treat a common long disease in premature babies (photo courtesy of Atefeh Mohammadi)

Gayatri Kumar

Topic

Our Community

Temerty Faculty of Medicine

Faculty of Dentistry

Forestry

Graduate Students

John H. Daniels Faculty of Architecture

Laboratory Medicine and Pathobiology

Research & Innovation

School of Graduate Studies

As an undergraduate student, Atefeh Mohammadi used to attend the Three Minute Thesis (3MT) competition with a friend – “for funsies,” she says with a laugh – and watch in awe as the competing graduate students tried to present their research in just three minutes.

“I thought it was so fun and so cool,” she says. “And, of course, so challenging.”

It was a challenge Mohammadi met head on. Earlier this month, the second-year master’s student from the Temerty Faculty of Medicine’s department of laboratory medicine and pathobiology placed first in the 3MT final, taking home the top prize at the annual competition for her presentation on neonatal lung disease.

“It’s every grad student’s dream to get a platform to talk about what you do,” she says about her decision to enter this year’s competition. “And the other thing is that I love science communication. I believe very strongly that everyone should make their research accessible to the public.

“What’s the point of doing what you’re doing and arriving at your findings if you’re not going to communicate that to the people who can use them?”

Mohammadi was one of nine finalists in this year’s competition, which challenges participants to present the complexities of their research to a generalist audience in just three minutes, using only one static slide. The global higher-education event has been one of the signature programs of the Centre for Graduate Professional Development since 2013 and encourages graduate-student researchers to develop their public engagement skills.

Judges assess the presentations for clarity, comprehension and engagement, rather than the quality of the research. The winner of the U of T final receives a $1000 prize, as well as the opportunity to compete in the Ontario-wide final featuring winners from other universities.

This year’s winners also included: Shivam Sharma, of the Faculty of Dentistry, who won both second place and the People’s Choice Award for his presentation on wound-healing in diabetes patients; and Melanie Wheatley, of the Institute of Forestry and Conservation in the John H. Daniels Faculty of Architecture, Landscape, and Design, who won third place for her presentation on fighting forest fires from the sky.

As for Mohammadi, her presentation focused on how citrulline, a compound occurring naturally in watermelons, can help treat bronchopulmonary dysplasia (BPD) – a common lung disease in premature babies that causes tissue damage in the grape-like alveoli (air sacs) of the lungs. Existing courses of treatment for BPD produce inconsistent results and have many side effects. But if Atefeh can confirm that the substance does indeed help alveolar cells (specifically, the type 1 cells) fight off inflammation, her findings may pave the way forward to a safe and inexpensive treatment.

As with her research protocol, Mohammadi says the most difficult element of the competition was figuring out where to start. During the competition’s first round, she says she worried that offering too many details about her work would scare off her audience. But the feedback she received after each round encouraged her to include more details of her research and learn to trust her material.

Finding the balance between scientific sophistication and accessible communication is something Mohammadi considers a lot in the course of her work. For the past three years, she has been a show host as well as the social media and promotions lead for the Raw Talk Podcast, a student-led project from the Institute of Medical Science that aims to bring medical science innovation to the general public in an accessible, engaging format. (Now in its sixth season, Raw Talk has tackled a variety of topics, ranging from underrepresentation in STEM to refugee health care in Canada and the science and ethics of organ donation.) Next year, Atefeh will move into a new role as one of the podcast’s executive producers.

Mohammadi says she often feels like there’s a wall with scientists on one side and the public on the other. “Especially now with the pandemic happening and the spread of misinformation, there’s a real need to break down that barrier between scientists and the general public,” she says. “Building that trust has become so important. And social media is where it all happens.”

She’s also glad to note that senior academics and faculty members are beginning to recognize the importance of non-traditional methods for disseminating student research. “For some people, it’s a complete shift. In the past, they might have thought it a waste of time – ‘You could be doing research instead, or publishing’ – but that attitude is changing.”

As for other graduate students who might be considering the competition, Mohammadi encourages them to sign up. “I can’t think of a reason why you shouldn’t do it,” she says. “3MT will help you understand for yourself the most important aspects of your work, and also what aspects need to be translatable to make its value known. I went into it with no pressure on myself, which I would recommend to everyone.

“It’s the perfect challenge for graduate students.”

U of T researcher explores ways to make Toronto’s urban forests, ravines more inclusive

Christopher.Sorensen — Mon, 12 Jul 2021 15:15:56 +0000

U of T researcher explores ways to make Toronto’s urban forests, ravines more inclusive

Christopher.Sorensen Mon, 07/12/2021 - 11:15

Cutline

Ambika Tenneti, a PhD student at U of T, is investigating community engagement in the city’s urban forests, looking specifically at factors that lead to inclusion or exclusion among immigrant communities (photo by Don Campbell)

Gilbert Ndikubwayezua

Topic

City & Culture

Diversity and Inclusion

Cities

Forestry

Graduate Students

John H. Daniels Faculty of Architecture

U of T Scarborough

When it comes to ensuring access to Toronto’s urban forests, Ambika Tenneti says simply living near a tree canopy is insufficient for many city residents.

“Access is not just about proximity,” says Tenneti, a doctoral student in the forestry department at the University of Toronto’s John H. Daniels Faculty of Architecture, Landscape, and Design.

People may live near a ravine, but if there’s no entrance near where they live and they have to walk, bike or take the public transit before getting into it, then it’s not accessible, she says. She notes that such trips also cost time and money, which recent immigrants often lack when they first arrive.

There can also be psychological barriers that prevent people from enjoying the ravines and other natural areas in the city – which is where Tenneti’s research comes into play. As a recent immigrant to Canada from India, where she studied environmental science, Tenneti investigates community engagement in the city’s urban forests, looking specifically at factors that lead to inclusion or exclusion, with a focus on the experience of new immigrants.

Her research suggests that immigrant communities are interested in urban nature, and enjoy it, but tend to prefer parks over wilderness areas. She says that, in general, immigrant communities feel more comfortable going to well-maintained, multi-use green areas where children have access to playing fields and other amenities such as seating, equipment, trees and gardens. Access to washrooms and drinking water are also important for planning family outings.

She points to Morningside Park in Scarborough, which is a popular destination for nearby residents – especially during the annual salmon festival or other summer events.

“It is a beautiful park with a lot of amenities, but it’s also not easily accessible,” says Tenneti, whose PhD supervisor is U of T Scarborough Associate Professor Nicole Klenk, who is an expert on the role of environmental science in society. She adds that the park is only accessible by car or bus, and once people arrive at the nearest bus stop, they still need to walk about 200 meters down a steep incline into the valley – a major challenge for children, older family members or those using a wheelchair or other mobility devices.

Wilderness areas such as ravines are also relatively unknown to recent immigrants, Tenneti says, adding that they are often described as “hidden gems” or “secret spaces” by long-time residents of the city – the majority of them white, affluent residents who live nearby.

“These remain a secret by lack of access, and a lack of knowledge and awareness among ethnically diverse immigrant communities,” says Tenneti. “Ravines are meant as throughways for walking, hiking or biking, but often these community members don’t see themselves engaging in these activities and this makes them hesitant to use ravines.”

One misconception is that immigrant communities fear wilderness areas because of bears. “That’s not so,” says Tenneti. “The immigrants I have spoken to know there are no bears in Toronto. Their fear stems from other factors such as getting lost or not finding the exits, especially in trails and woods.”

She says fear of getting robbed or attacked, off-leash dogs, coming across people indulging in inappropriate behaviour or activities are also a concern.

There is also fear stemming from a lack of ecological knowledge about nature in the Greater Toronto Area. Immigrants may hear about ticks, coyotes, giant hogweed and poison ivy, adds Tenneti, but many don’t know how to recognise such threats or what to do if they come in contact with them. Tenneti says immigrant communities are keen to learn how to identify plants that they need to be wary of – as well as those they need to protect – but the necessary resources are seldom available.

“One fear that surprised me was ‘the gaze’ or ‘the look,’” Tenneti says. “This was shared by Muslim and Black youth who said they were comfortable going to parks and ravines in their neighbourhoods, but not in white-dominant areas. Despite no one saying anything, they felt othered and uncomfortable.”

Another issue is that education organizations tend to focus on engaging children and youth, but not necessarily the adults who often decide where kids and other family members will go for a walk or outdoor recreation.

For the city’s urban forests and canopies to thrive and be representative of its diverse population, Tenneti says it is important to make the necessary investments in the city’s ethnically diverse neighbourhoods. In addition to having proper signage, trails, garbage bins, public washrooms and seating, she says there is a need to engage people in stewardship activities, organize outdoor education workshops and leaning activities, and actively promote participation. Such programs should also be shared through local community centres, settlement agencies and ethnic media organizations.

“Ultimately, without social justice you cannot have environmental justice,” Tenneti says.

A walk in the park? How spending time in nature can boost mental health

Christopher.Sorensen — Thu, 04 Mar 2021 23:20:22 +0000

A walk in the park? How spending time in nature can boost mental health

Christopher.Sorensen Thu, 03/04/2021 - 18:20

Cutline

The mental health benefits of spending time outdoors, and in nature, are well-known and are particularly important during the COVID-19 lockdown (photo by Nick Iwanyshyn)

Topic

John H. Daniels Faculty of Architecture

Mental Health

If you’re feeling stressed, anxious or discouraged, finding the energy to get outdoors may be hard – but it could be one of the best things you could do to lift your mood, particularly during COVID-19.

Ontario health-care providers are now offering “Parks Prescriptions” through a new program called PaRx that recommends spending time in nature as a way to fight depression and other ailments.

The initiative, started by the BC Parks Foundation, cites research that states our stress-hormone levels drop significantly after just 15 minutes of sitting in a forest. Spending time in nature also boosts memory, creativity and work satisfaction, according to the program.

Likewise, the Centre for Addiction and Mental Health says nature can have a nurturing effect on your mental health. Even just spending 15 to 20 minutes per day outdoors in nature can be beneficial, research shows.

Danijela Puric-Mladenovic, an assistant professor of forestry at the University of Toronto’s John H. Daniels Faculty of Architecture, Landscape, and Design, has been championing the healing properties of nature for decades.

She is an avid hiker who regularly spends weekends exploring Ontario’s trails with her children and Shetland sheepdog.

In a recent conversation with U of T News, Puric-Mladenovic discussed the importance of forests and the outdoors in general to our well-being, as well as the urgency of increasing accessibility to green space in and around Toronto.

How important is it to get outdoors, or spend time around trees?

Human health depends on nature. In Japan, they realized that the urban population was having all sorts of health issues, so their ministries of forestry and health worked together to research and advocate for the benefits of “forest bathing” – or what most of us know as hiking. They discovered that, physiologically, our bodies and cells react positively to spending time in nature.

If you have forests, there are a multitude of benefits. In addition to being good for our health, trees provide a natural climate solution. The cheapest and most sustainable way to address many environmental problems is to plant trees.

How did you discover your passion for forests?

Growing up in Serbia, we were educated from elementary school onwards to understand nature and forests as fundamental to human health. We walked everywhere, and we were surrounded by nature. On the weekends, we joined hiking clubs whose membership ranged from seven to 90 years of age. We would drive to a hiking area and stay for two days. So, there’s a social aspect to the experience, too. Nature brings people together.

In Europe, it’s not uncommon for doctors to prescribe time in nature for a variety of conditions, whether that is asthma or a mental health issue. Many mental health institutions in Europe are located outside of the city, up in the mountains and on huge properties with lots of forest cover. There might be pine trees, whose scents have a positive impact on our breathing. People there are asked to do repetitive tasks like gardening to help them relax. These institutions are part of the health network.

Marc Johnson, an associate professor of biology at U of T Mississauga, recommends spending 30 minutes daily in nature to help boost your mood, in this installment of the series Battling Burnout.

How have people’s relationships to nature changed as a result of COVID-19?

With the pandemic, every park, conservation area and woodlands around the Greater Toronto Area has had more visitors than I have ever seen. Humans have long been arrogant about our relationship to nature, as if we are above it, but COVID was a tipping point because there was nothing else to do and we realized the beauty of nature.

This summer, I saw so many people walking out in the street in my neighbourhood. Everyone was drawn to the green spaces – the streets with more trees. This is a wake-up call to prioritize the design and protection of our green spaces.

What are some of the issues surrounding accessibility to green space in Toronto?

We are losing tree canopy in our city, and our urban sprawl is terrible. Our parks and protected areas are great, but it’s not sustainable for people to have to drive an hour to get to Algonquin Park to have that kind of access. Within the forestry program at U of T, we are always engaging with communities to help them manage their green residential areas and their tree inventories.

As members of the public, we must demand equal access to green space. This is as important as access to clean drinking water. There are some parts of Toronto and other cities where people have no access to green space – a few puny trees don’t count. We have to demand from our politicians that networks of larger parks and protected areas are established in the city. And, as individuals, we can do our part by helping to plant trees. This is an activity that will make you feel great mentally because you are helping to create our future green spaces and future communities. Plus, it’s a physical activity that you don’t need to go to the gym for.

Here are a few recommendations for some nature spots to visit in and around Toronto, with input from Puric-Mladenovic (However, keep in mind that Ontario Parks recommends only visiting provincial parks or conservation areas close to home and not to travel outside your area during COVID-19):

Rouge National Urban Park: U of T Scarborough students have developed an app that guides you through this park
Mount Pleasant Cemetery: An arboretum that connects to the Belt Line and through Moore Park ravine to Evergreen Brickworks
Durham Regional Forest: more than 16 km of trails, near the Township of Uxbridge, Ont.
Ganaraska Forest: near Clarington, Ont. A day pass is required
Oak Ridges Moraine Trail: a 300 km-long trail that winds from that winds from the Caledon, Ont east to Castleton, Ont.
Scarborough Bluffs: 11 parks along the shore of Lake Ontario with spectacular views of the towering bluffs. Visitors are warned not to approach the edge of the bluffs
Cedarvale Ravine & Nordheimer Ravine: a 7.2 km out-and-back trail through the heart of Toronto
Tommy Thompson Park: a unique Park located at the end of the Leslie Street spit in Lake Ontario, with trails, bird-watching a spectacular city views

And if you are under quarantine or can't get outside?

People around the world are finding that looking at nature virtually can help

Find out more about mental services and supports at U of T

U of T training and research program to focus on green roofs, other 'living' infrastructure

Christopher.Sorensen — Fri, 15 Jan 2021 21:09:32 +0000

U of T training and research program to focus on green roofs, other 'living' infrastructure

Christopher.Sorensen Fri, 01/15/2021 - 16:09

Cutline

The DLIFES network provides training in the design, construction and management of engineered vegetative systems such as rooftop gardens (photo courtesy of the Daniels Faculty)

Topic

Our Community

Cities

Faculty of Applied Science & Engineering

Forestry

Graduate Students

John H. Daniels Faculty of Architecture

Research & Innovation

Sustainability

U of T Scarborough

A new initiative at the University of Toronto is training students in the design, construction and management of engineered vegetative systems for cities facing the impacts of rapid urbanization and climate change.

The Green Roof Innovation Testing Laboratory (GRIT Lab) at the John H. Daniels Faculty of Architecture, Landscape, and Design recently launched the Design of Living Infrastructure for Ecosystem Services (DLIFES) Network. It’s a five-year-long NSERC CREATE program that will train more than 50 undergraduate, master and PhD students, as well as post-doctoral researchers.

“Governments and private property owners across Canada and worldwide are investing heavily in living infrastructure in order to address current and future challenges of environmental degradation, pollution, habitat loss, and extreme climate events,” says Liat Margolis, an associate professor of landscape architecture.

“This presents a tremendous opportunity to develop 21st-century approaches to education and professional practice that are interdisciplinary by nature, empirical, hands on and engaged with regional urban policy and industry practices.”

The GRIT Lab, which has been in operation for a decade, is an international hub of interdisciplinary and experimental research on living green infrastructure that was spearheaded by Margolis in collaboration with Jennifer Drake and Brent Sleep in the Faculty of Applied Science & Engineering, Scott MacIvor in U of T Scarborough’s department of biological sciences, and Sean Thomas in Daniels’ department of forestry.

The first of its kind, the DLIFES network was launched last summer and extends throughout Canada, with academic partners at U of T Scarborough, Ryerson University, Saint Mary’s University and the University of Saskatchewan.

The network also collaborates with eight other universities in the United States, France, Israel, Australia and Japan that are well known for their green infrastructure experimental labs.

The NSERC funding will provide participating students with opportunities for research exchange abroad. Several industry and government partners contribute to the project through technical instruction, advisory board membership, field work opportunities and in-kind material donations.

Recently constructed, sloped green roofs provide new research opportunities (photo courtesy of the Daniels Faculty)

The DLIFES inaugural summer program was delivered online due to COVID-19. It kicked off with its first annual symposium in June. The symposium brought together project partners to share research findings and insights on project implementation across a broad range of contexts and climates. A virtual networking event allowed students to connect with experts in design, construction, environmental legislation and conservation fields.

Over a period of four weeks, interdisciplinary coursework delivered by academic, government and industry partners offered technical training to 22 students in landscape, forestry, engineering and biology. Students had opportunities to develop command of green roof and low impact development design and construction, including soil design for bio-retention and green roof growth media, as well as subsurface urban hydrology.

Over the next four years, the program's coursework will cover a range of technical aspects related to landscape design and construction, plant biology and ecology, soil physics and bio-material sourcing and processing, storm water management, treatment and reuse, sensor instrumentation design and data visualization.

“This program offers the specialized and practical field-based training that is currently lacking and absolutely critical as technologies and new regulations are rapidly changing,” says Drake, a DLIFES principal investigator. “For example, the 2017 federal budget designated upwards of $20 billion in green infrastructure projects over the next decade. New York City’s green infrastructure plan has allocated US$1 billion for new projects to reduce combined sewer overflow. And, in 2019, they legislated a green roof bylaw like that of Toronto’s as part of their commitment to the Green New Deal.”

Cistern-collected runoff versus potable water irrigation systems are tested on the roof at One Spadina (photo courtesy of the Daniels Faculty)

Second-year Master of Landscape Architecture (MLA) student Howard Rosenblat studied environmental science and corporate sustainability before joining the graduate program at Daniels, giving him a unique perspective on the green industry.

“I love peeling back the layers to look at different systems, and I find that design is often disconnected from functionality,” he says. “That is what I loved about these courses. They really make you question the why and how.”

Madison Appleby is also in her second year of the MLA program.

“The DLIFES summer program fostered connection and the exchange of information, helping to bridge the gap between disciplines and prevent mistranslation,” she says. “The exposure to innovative research and industry practices, as well as a critical approach to ‘green design,’ is a way of thinking that I will carry forward into my schoolwork and eventual practice.”

In addition to the summer courses and annual symposium, the DLIFES Create Program is leading a number of cutting-edge research projects, one of which is the study of cistern-collected surface runoff for reuse in green roof irrigation. This will provide insight into the role of green roofs in mitigating urban pollution and linking site hydrology between the landscapes at the ground and roof levels.

Another major study being undertaken as part of DLIFES is a survey of the city of Toronto’s green roofs since 2009. Forestry PhD candidate Wenxi Liao and MLA students Rosenblat, Appelby, Allison Smith, and Stefan Herda employed remote sensing techniques to geolocate roughly 700 green roofs, evaluate their endurance or decline over time and measure the overall effectiveness of green roof practices in Toronto.

The new GRITlab at One Spadina was constructed in part thanks to funding from the University of Toronto Lab Innovation for Toronto (LIFT) project. The experimental facility was designed by Baird Sampson Neuert Architects (BSN) with in-kind donations by industry partner Bioroof Systems.

Using tree bark, U of T researcher develops new generation of sustainable products

Christopher.Sorensen — Thu, 29 Oct 2020 15:39:51 +0000

Using tree bark, U of T researcher develops new generation of sustainable products

Christopher.Sorensen Thu, 10/29/2020 - 11:39

Cutline

U of T's Ning Yan and her collaborators in the Low-Carbon Renewable Materials Centre are developing a new generation of products made from forestry biomass, including underutilized materials such as tree bark. (Photo: Tyler Irving)

Tyler Irving

Topic

Our Community

Daniels Faculty of Architecture

Faculty of Applied Science & Engineering

Forestry

Sustainability

Canada’s forests are a key source of renewable materials, from paper to lumber. Yet many of the industry’s most common products, such as cardboard and newsprint, are on the low end of the value chain.

It’s a shortcoming the University of Toronto’s Ning Yan aims to rectify.

“The analogy we use is to a petroleum refinery, where the crude oil feedstock is made into thousands of different products, from lower-value fuels to higher-value commodity chemicals,” says Yan, a professor in the department of chemical engineering and applied chemistry in the Faculty of Applied Science & Engineering. “We can do the same with our renewable resources, such as forest biomass.”

Yan is the director of the newly formed Low Carbon Renewable Materials Centre (LCRMC) at U of T Engineering, which is supported by the dean’s strategic fund. LCRMC researchers work closely with forestry companies and industry associations to transform forest biomass – including materials that today are discarded as waste – into commercially valuable products.

In some cases, the new products would be the same as those that currently come from fossil fuels, enabling more oil to stay in the ground. In others, they could be combined with fossil-fuel derived products to enhance their performance.

Much of Yan’s research focuses on tree bark, which she believes is currently underutilized in pulp mills.

“Right now, bark is typically burned as a low-grade fuel in order to generate energy,” says Yan, who is cross-appointed to the department of forestry at the John H. Daniels Faculty of Architecture, Landscape, and Design. “But from an engineering perspective, it contains all kinds of unextracted value.”

One example is epoxy resins, a group of chemicals that are widely used in industrial-strength adhesives and composites.

“Epoxies are used in everything from flooring to airplane composites,” says Yan. “One of the key chemical building blocks of epoxies is bisphenol A (BPA), which industry would like to phase out because of its potential health impacts.”

Yan and her team have shown that bark extracts can be used to make a BPA-free epoxy resin. Like the traditional product, bark-derived epoxy resin can be mixed with a hardener to create an industrial-strength adhesive.

Made from oil extracted from bark and mixed with CO2, this cyclic carbonate is a precursor for polyurethane, a common form of plastic with a wide range of everyday uses (photo by Heyu Chen)

Another recent line of research involves polyurethanes, a class of polymer chemicals that are used in an array of products, including couch cushions, synthetic clothing and even house insulation. As with epoxies, polyurethanes are made using ingredients with potentially negative health impacts.

“Most commercial polyurethane foams are made using isocyanate, which is a toxic chemical,” says Yan. “Even worse, isocyanate is made from phosgene, which is even more toxic – so much so that it was used as a chemical weapon using the First World War.”

Yan and her team showed that tree bark can be used to create an isocyanate-free version of polyurethane. The bark is liquefied into an oil, which is then mixed with CO2 to create a product known as cyclic carbonate, a precursor for polyurethane. The cyclic carbonate product contains 15 per cent CO2 by weight, providing a new path to sequestering the greenhouse gas.

Last month, the team published a new method for making different kind of polyurethane precursor. Shape-memory polyurethane (SMPU) is used in mattresses, shoes and many other products. Yan and her team created a new form of SMPU from abietic acid, a chemical extracted from tree bark.

These samples of shape-memory polyurethane (SMPU) are made from abietic acid, a chemical extracted from tree bark (photo by Pitchaimari Gnanasekar)

While the proof-of-concept studies are encouraging, Yan says that there is still some distance to go before the products can be commercialized.

“There are still some challenges with respect to performance, especially in terms of strength,” says Yan. “We also have to consider how these chemical processes will be scaled up so that they can be implemented on an industrial scale.”

LCRMC researchers are working with players along the value chain, from polymer foam companies such as Woodbridge to pulp and paper companies such as Domtar, as well as organizations focused on research and development such as FPinnovations.

Together they aim to create new pathways to translate their innovations into full-scale applications.

Says Yan, “I see this as an opportunity to develop a greener, more sustainable economy.”

U of T researchers to co-lead national Wildland Fire Research Network

Christopher.Sorensen — Wed, 08 Jul 2020 19:31:06 +0000

U of T researchers to co-lead national Wildland Fire Research Network

Christopher.Sorensen Wed, 07/08/2020 - 15:31

Cutline

Smoke billows into the sky near Fort McMurray, Alta. in May 2016 (photo by Cole Burston/AFP via Getty Images)

Topic

John H. Daniels Faculty of Architecture

Research & Innovation

Two University of Toronto professors are among the scientists leading the Wildland Fire Research Network – a new, Canada-wide coalition of seven forest-fire researchers at six different academic institutions.

Professor Emeritus David Martell and Associate Professor Patrick James, both of the John H. Daniels Faculty of Landscape, Architecture, and Design's forestry department, have been tapped to play key roles in the new network, which aims to increase Canada's expertise in wildland fire science.

As part of the initiative, James and Martell will have access to new funding earmarked specifically for the purpose of training new master's, PhD, and post-doctoral students in forest-fire research techniques. The federal government said it would be partnering with the Natural Sciences and Engineering Research Council of Canada (NSERC) to provide $5 million for the creation the Wildland Fire Research Network.

“I have three new PhD students who have already signed on, and there will be more in the future,” James says. “Without this grant I wouldn't have had the financial means to take on these students. It's a huge boost to our forestry group.”

James is a specialist in landscape-scale forest disturbance processes, including the destruction wrought by the spruce budworm and the mountain pine beetle – insects whose fecundity and voracious feeding habits make them capable of killing vast swaths of Canadian forests (the dry, dead trees they leave behind can act as tinder when exposed to fire).

Martell is co-director, with Mike Wotton, of the Fire Management Systems Laboratory. He studies new techniques for detecting and managing forest fires.

An increase in the number of trainees isn't the only benefit for the U of T researchers. “It's not just about increasing the number of students,” Martell says. “It's about increasing the breadth of expertise of people who are interested in fires.”

By drawing on the varied backgrounds and institutional connections of the network's participants, students will be able to study forest fires from the perspectives of different disciplines, including ecology, physics, chemistry and the social sciences.

Students from across the new research network will also have opportunities to meet each other and form valuable professional connections. “The most important thing we're going to do is have 'summer schools,’” Martell says. “We’re going to bring our graduate students together. Students will make presentations, and we'll bring in professors to give talks – but, most importantly, the students will start to network with each other.”

The end result will be a new generation of highly qualified researchers and professionals with the skills, knowledge and interpersonal connections necessary to protect Canada's forests and forest-adjacent communities for decades to come.

The infusion of money into Canadian forest-fire research comes at an opportune moment: With climate change continuing unabated, scientists expect forest fires to become more frequent and more severe. According to federal government statistics, there are approximately 8,000 fires in Canadian forests each year.

Although fires can be a natural and healthy part of a forest's lifecycle, they pose a threat to human safety when they approach what's known as the wildland-urban interface – the border between the natural world and dense human settlements. Recent disasters like the 2016 Fort McMurray wildfire and the 2011 Slave Lake wildfire have demonstrated the potential costs of a lack of investment in forest-fire research and control.

“This grant is a response to those events, and a recognition that we need more people to work on these problems,” Martell says.

Here's the list of researchers who will be leading the Wildland Fire Research Network:

Mike Flannigan, University of Alberta

Lori Daniels, University of British Columbia

Laura Chasmer, University of Lethbridge

Douglas Woolford, Western University

Mike Waddington, McMaster University

Patrick James, University of Toronto

David Martell, University of Toronto

U of T researcher co-authors global study on tropical forests' diminishing capacity to absorb carbon

Christopher.Sorensen — Wed, 04 Mar 2020 21:22:09 +0000

U of T researcher co-authors global study on tropical forests' diminishing capacity to absorb carbon

Christopher.Sorensen Wed, 03/04/2020 - 16:22

Cutline

Sean Thomas was a co-author on an international study, involving more than 100 institutions, that found the world's tropical forests are losing their ability to absorb carbon from the atmosphere (photo by Sean Thomas)

Topic

John H. Daniels Faculty of Architecture

Research & Innovation

Sustainability

The world’s tropical forests are losing their ability to remove carbon dioxide from the atmosphere – a development that could have serious implications on efforts to forestall climate change.

That is one of the findings of an international study by dozens of researchers – including the University of Toronto’s Sean Thomas, a professor of forestry at the John H. Daniels Faculty of Architecture, Landscape, and Design – that was featured on the cover of this week’s issue of Nature.

In the mid-1990s, Thomas helped establish four 10-hectare research plots in the Ituri Rainforest in what is now the Democratic Republic of the Congo. The densely treed areas, teeming with small forest antelope, monkeys, and the occasional zebra-striped okapi, were essentially living laboratories that, a quarter century later, yielded key data for the global study led by researchers at the University of Leeds.

“Intact tropical forests have been offsetting global carbon dioxide emissions, [but] that's going to go away,” says Thomas of the study’s findings.

“That makes the problem of achieving the goals of the Paris Accord and stabilizing temperature increases much more difficult."

Using tree measurements from Thomas's research forests, along with similar measurements from hundreds of other tropical forests in Africa and South America, the study's researchers concluded that intact tropical forests – that is, those that haven't been logged or otherwise commercially exploited – absorbed only about six per cent of manmade carbon emissions by the 2010s. That’s compared to 17 per cent in the 1990s.

Furthermore, the study’s results suggest the forests’ ability to remove carbon will keep declining in the future.This means the ability of tropical forests to absorb and capture carbon has already passed its peak. In the parlance of environmental scientists, these forests are becoming "carbon saturated."

Trees capture carbon by absorbing carbon dioxide from the air and chemically transforming it, via photosynthesis, into the complex sugars that fuel tree growth. When a tree dies, the opposite happens: it releases carbon back into the environment as it decomposes.

Scientists have long understood that intact tropical forests are capturing more carbon than they're releasing, essentially scrubbing the atmosphere of manmade pollutants.

Sean Thomas conducts research in the forests of Ecuador (photo by Pedro Guayasamin)

Until recently, the general scientific assumption was that the net amount of carbon being captured by each hectare-sized unit of these forests was mostly unchanging. That's partly because carbon dioxide is tree food. If humans add more of it to the atmosphere, as they have been doing since the industrial revolution, plants have more fuel available to them. Well-fed plants absorb more carbon dioxide. It's a feedback loop, and it means that forests can, to a certain extent, increase their carbon capture capacity in sync with increases in atmospheric carbon dioxide.

But, according to Thomas and his co-authors, that beneficial feedback process is not what's currently happening in Africa and South America because too many trees are dying. The scientists aren't sure why tree death is increasing, but climate change is considered a likely culprit.

As a result, these tropical forests are losing their ability to capture more carbon than they produce. If the trend continues, the forests may actually become a net source of carbon, rather than a carbon sink. In other words, the amount of carbon released into the environment from decaying plants will be greater than the amount of carbon absorbed by living plants.

"That point of diminishing returns has been thought to be not for a long while, maybe 100 years away," Thomas says. "Now we know that it's already here, or imminent.”

Thomas's role in the study, which involved participation from nearly 100 different institutions, was to help analyze three decades' worth of measurements of the heights and diameters of trees in the four Congolese research forests he played a part in establishing so many years ago. Using those numbers, he was able to extrapolate information about how the forests' ability to capture carbon has changed over time. He also participated in writing the final paper.

The details of the study's findings are sobering. The intact tropical forests of Amazonia – the rainforest region of South America – are rapidly losing their ability to capture carbon. The study predicts that, by 2030, those forests will have lost so much of their carbon capture ability that they will be a net source of carbon.

In African tropical forests, the subject of Thomas's analysis, the data points to a different conclusion.

Unlike South America's forests, Africa's intact forests haven't shown a significant decline, per hectare, in their carbon capture ability over the past three decades. But they aren't immune to the same sort of decline currently afflicting the Amazon. The latest data shows the beginnings of a slower downward trend that could dramatically reduce Africa's carbon capture in coming decades.

The divergence in the fates of the two forests is likely related to differences in geography. "The Amazon has much lower elevation, on average," Thomas says. "At the mouth of the Congo is a series of waterfalls, so it's completely above the elevation of the Amazon." The higher elevation makes African forests cooler and less prone to the adverse effects of global warming.

As dire as the study's findings may seem, Thomas cautions that the reality may actually be even worse, because researchers weren't able to take all possible measurements of carbon saturation into account.

"This study is all based on live tree measurements," Thomas says. "But a large part of the carbon in forests is in the soil. What you worry about, as temperatures increase, is that the decomposition processes in the soil will be accelerated, and there will be loss of soil carbon."

U of T researchers, innovators to pitch ideas for Ontario's growth at annual economic summit

rahul.kalvapalle — Tue, 12 Nov 2019 20:41:00 +0000

U of T researchers, innovators to pitch ideas for Ontario's growth at annual economic summit

rahul.kalvapalle Tue, 11/12/2019 - 15:41

Cutline

Pepper, a socially assistive robot developed in the lab of U of T's Goldie Nejat, is designed to detect and respond to human voices and gestures (photo by Liz Do)

Rahul Kalvapalle

Topic

Our Community

Advanced Manufacturing

Ontario Impact

Alumni

Entrepreneneurship

Faculty of Applied Science & Engineering

Forestry

John H. Daniels Faculty of Architecture

Leslie Dan Faculty of Pharmacy

Mechanical & Industrial Engineering

Research & Innovation

Robotics

When it comes to using robots to help the elderly, the future is almost here.

That’s according to University of Toronto robotics expert Goldie Nejat, who says we’re only a few years away from deploying robots in long-term care facilities to help residents everyday tasks, exercise and cognitive stimulation.

Her long-term vision is to design robots that can assist with an array of tasks to improve seniors’ quality of life, alleviate some of the burden on their caregivers and family members – and, ultimately, contribute to the expansion of the Ontario economy.

“Health-care robotics is growing substantially, and U of T is at the cutting edge of designing these robots,” says Nejat, an associate professor in the department of mechanical and industrial engineering in the Faculty of Applied Science & Engineering.

“We’re training the next generation of skilled researchers and entrepreneurs to develop this technology and integrate it into our health-care system to assist people who need the care.”

On Wednesday, Nejat, who holds a Canada Research Chair in Robots for Society, will be one of four presenters pitching their ideas to the audience at the Ontario Economic Summit. The annual event is organized by the Ontario Chamber of Commerce and brings together industry representatives, experts and government officials to talk about the province’s economy. The theme for this year’s edition – taking place at the Beanfield Centre at Toronto’s Exhibition Place – is competitiveness. Premier Doug Ford and Mayor John Tory, a U of T alumnus, are scheduled to attend.

Goldie Nejat and a student interact with a socially assistive robot named Tangy, which is designed to facilitate recreational activities and promote social interaction among people with degenerative cognitive conditions such as dementia (photo by Laura Pedersen)

Nejat and three other members of the U of T community will take part in a session titled “The Next Big Idea.” Each will each present a pitch for how a hypothetical public investment of $100 million in their respective sectors could be utilized to drive competitiveness and economic growth in the province.

Nejat will discuss how socially assistive robots can help adults living with dementia as well as health-care workers; Hani Naguib, a professor in the department of mechanical and industrial engineering and director of the Toronto Institute for Advanced Manufacturing, will discuss how advanced manufacturing and smart materials can usher in a revolutionary transformation for factories and industry; Anne Koven, an adjunct professor in the forestry program at the John H. Daniels Faculty of Architecture, Landscape, and Design and executive director of the Mass Timber Institute, will talk about how mass timber and tall wood construction can sustain a mutually beneficial relationship between the forestry industry and thriving urban markets; and Allen Lau, a U of T alumnus and the founder and CEO of data-driven publishing platform Wattpad, will talk about how to nurture Ontario’s tech ecosystem into a global powerhouse.

The session will be moderated by Christine Allen, U of T’s associate vice-president and vice-provost, strategic initiatives, and a professor in the Leslie Dan Faculty of Pharmacy.

"The Ontario Economic Summit represents an incredible opportunity to strengthen dialogue between academia, industry and government on how we can all work together for the betterment of our province,” says Allen, who is also the co-founder of medical nanotechnology startup Nanovista.

"I'm delighted that the audience will have the opportunity to learn about how the university’s research and talent are leading the way in the development and application of some of the most revolutionary technologies of our time – innovations that are improving Canadians’ lives and contributing to the economic health of the province.”

One of the session's participants is likely to stand out in the crowd, according to Nejat.

“We’re going to take one of our robots and have a demonstration where it engages people to do a few exercise sessions with it,” she says.

That’s a capability that Nejat and her team are also preparing to test in a two-month study that will see the robot lead residents of a long-term care facility through physiotherapist-approved exercises.

“We’ll assess residents’ acceptance of the robot ... and any other feedback during the interaction,” says Nejat.

Nejat’s robots have already spent time in long-term care facilities, where residents, family members, caregivers and administrators have been given the chance to have “meet-and-greet” sessions with them.

“It’s interesting to see how naturally people interact with social robots. They talk to the robot in a similar way that they talk to people. They respond to it, they’re engaged,” says Nejat. “This shows the capabilities and potential of the technology.”

Nejat says robots hold promise in providing older adults with cognitive stimulation.

“Dementia is a worldwide epidemic for which there’s no cure, so it’s important for us to look at using technology to help us live with a certain quality of life as we age and our population demographics change,” she says. “It’s important for older adults to be healthy as they age, be active and take part in social interactions. There’s a lot of potential for robots to support their everyday lives in this way.”

Nejat says U of T’s prowess in robotics and related technologies like AI, as well as Toronto’s bustling innovation and startup ecosystem, makes it the perfect place in which to grow the sector.

“In addition to improving people’s lives, this sector can spur job creation through startups and spin-off companies, as well as the entry of established robotics companies. My pitch at the Ontario Economic Summit will centre on how robotics can help with everyday life, support us as we age and contribute to job creation and economic prosperity in the province.”

Forestry

What's with those colours? Sean Thomas on the science behind this year's fall foliage

Read more at CBC

Read more at CTV

Researchers study plants sprouting from century-old seeds uncovered during Toronto Port Lands excavation

From watermelons to forest fires, U of T graduate students unpack research in three-minute thesis competition

U of T researcher explores ways to make Toronto’s urban forests, ravines more inclusive

A walk in the park? How spending time in nature can boost mental health

Find out more about mental services and supports at U of T

U of T training and research program to focus on green roofs, other 'living' infrastructure

Using tree bark, U of T researcher develops new generation of sustainable products

U of T researchers to co-lead national Wildland Fire Research Network

U of T researcher co-authors global study on tropical forests' diminishing capacity to absorb carbon

U of T researchers, innovators to pitch ideas for Ontario's growth at annual economic summit