trees

An oasis of green: How �山ǿ�� keeps campus trees safe and healthy

rahul.kalvapalle — Thu, 13 May 2021 18:37:48 +0000

An oasis of green: How �山ǿ�� keeps campus trees safe and healthy

rahul.kalvapalle Thu, 05/13/2021 - 14:37

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The lush tree canopy is a key part of the �山ǿ�� campus experience, but few see the extensive care needed to maintain such a rich stock of healthy trees amid an unforgiving urban environment (photo by Laura Pedersen)

Rahul Kalvapalle

Topic

Our Community

Scott Mabury

Landmark

St. George

Sustainability

trees

�山ǿ�� Mississauga

�山ǿ�� Scarborough

With more than 3,300 trees – including Ontario’s largest concentration of elms and the city’s healthiest collection of ashes – the University of Toronto’s St. George campus is an oasis of green surrounded by Canada’s biggest metropolis.

The same can be said of �山ǿ�� Mississauga, located on 225 acres of protected greenbelt along the Credit River, and �山ǿ�� Scarborough, which is perched at the edge of the Highland Creek Ravine. In fact, the university’s trees are among the most stunning, photo-friendly features of the university’s three campuses.

But what most campus visitors never see is the painstaking work that goes into maintaining �山ǿ��’s considerable arboreal assets – from the grounds services crew who ensure trees are watered, fertilized and inoculated against diseases, to planning and project development experts who find ingenious ways to protect trees during construction and renovation projects.

Stan Szwagiel, manager of grounds services at the St. George campus, says trees require extra-special care if they are to thrive in the city.

“Trees haven’t evolved in urban environments,” he says. “They evolved in a natural state in a forest environment, and humans have come in and created an urban environment.

“So, we need to take care of all the components they need to survive – like soil, space, air getting to their roots and specific fertilization for certain species.”

Caring for �山ǿ��’s trees goes beyond preserving campus aesthetics. Across the university’s three campuses, trees collectively capture more than 5,260 tonnes of carbon dioxide per year, according to �山ǿ��’s Low-Carbon Action Plan. That’s in addition to providing benefits such as trapping pollutants, providing habitat for wildlife, reducing water runoff and supporting human well-being.

Szwagiel says staff carry out detailed inventories at regular intervals to keep tabs on �山ǿ��’s tree population.

The most recent effort on the St. George campus saw forestry students count trees and categorize them down into species, sizes, age estimations and health condition. They counted approximately 3,300 trees – not including those on the grounds of the federated colleges.

Trees at �山ǿ�� Scarborough (pictured), �山ǿ�� Mississauga and the St. George campus collectively capture 5,260 tonnes of carbon dioxide per year (photo by Nick Iwanyshyn)

There have also been efforts to make tree care high-tech.

Thanks to work by Szwagiel and grounds supervisor Peter Johnston, the St. George campus’s irrigation systems have been computerized – with 98 per cent of the campus now watered by a state-of-the-art remote water management system.

“We have much better control over watering now, because you can go to a computer and turn all the systems on or off at the push of a button – instead of me running around to 90 different controllers on campus and manually shutting them off,” Johnston says.

“If it’s going to rain tomorrow, we can shut the system off, so it’s a lot more efficient. We used to have to turn off all the controllers if it’s raining and then go right back and turn them all on again, which was very time-consuming.

“So, we have much better control over how much water we use.”

The irrigation upgrades have reduced annual water consumption from 29 million gallons in 2011 (before the new, computerized systems were implemented) to 13.6 million gallons in 2020 – a savings of over 15 million gallons of water per year.

Johnston noted that his team is always looking to incorporate the most efficient and eco-friendly tools into all aspects of their work. In recent years, this has included transitioning much of the campus grounds equipment, including push mowers, hedge trimmers and chain saws, from gas-powered units to battery-electric ones.

Watering and fertilizing – which is carried out twice a year, in the spring and fall – is just the first step of �山ǿ��’s tree-care regime.

“That’s like going to the doctor, getting a check-up and the doctor telling you to make sure you drink enough water daily and prescribing a multi-vitamin pill,” Szwagiel said. “That’s fine, it’s healthy – and it’s a good analogy to what a person would do. But then we needed to go further to see what else we could do to help our trees on campus.”

Enter species-specific health-care plans.

At St. George, the campus boasts what’s believed to be the province’s largest collection of mature elm trees, including in front of Simcoe Hall and on the west side of back campus. Their continued existence is thanks in large part to �山ǿ��’s program to protect the trees from Dutch elm disease, a highly infectious fungal disease that was first detected in Ontario in 1946 and has killed millions of elms around the world.

The inoculation protocol includes injecting a special fungicide into the trees.

“Dutch elm disease is basically caused by fungi which beetles spread from tree to tree,” Szwagiel says. “It then kills the elm within a few years of the tree getting these bacteria. So, we inoculate them every five years.”

�山ǿ�� Mississauga is located on 225 acres of protected greenbelt along the Credit River (photo by Randy Landicho)

Szwagiel and Johnston also implemented programs to stave off the emerald ash borer, an invasive species of beetle that was first detected in Ontario in 2002 and has killed millions of ash trees in both forested and urban environments.

“This beetle lays its eggs underneath the bark,” Szwagiel says. “When the larvae hatch, they start eating channels into the tree.”

The beetle is so destructive that up to 99 per cent of all ash trees are killed within eight to 10 years of the beetle arriving in an area, according to Natural Resources Canada.

“We inoculate our ash trees with a chemical that kills the ash borer before it can do that – while it’s still germinating,” says Szwagiel. “By doing this, we were able to save all our ash tree inventory.”

The white pine is yet another species of tree that has received specialized care.

“In forests, these trees grow in pine groves,” says Szwagiel. “Their needles are very acidic, and when they drop to the ground, they sort of fertilize the soil, adding to the bio-system that they live in.

“When we saw that our white pines on campus weren’t doing well, we reached out to an arborist to ask them what we can do. The arborist suggested a foliar type of fertilizer, which is applied directly on the needles. That’s made a huge difference.”

Special attention is also paid to tree condition and maintenance when it comes to planning major campus construction projects. In the case of the Landmark Project – a three-year endeavour to revitalize the historic core of the St. George campus – 43 trees will be carefully removed and 253 new trees planted in their place, resulting in a net positive of 208 trees.

The project includes the installation of a massive underground geoexchange field that will help reduce �山ǿ��’s greenhouse gas emissions by an estimated 15,000 metric tons per year.

Scott Ling, senior planner at University Planning, Design & Construction, said Landmark’s design plans achieve the lowest possible disruption to trees based on studies by arborists and consultants.

For example, a 150-year-old green ash tree in front of the J. Robert S. Prichard Alumni House on the northwest perimeter of King’s College Circle was preserved after staff found a way to work around the tree.

“It’s always unfortunate to have to remove trees, and a concerted effort was made to keep as many trees as possible based on the space planning requirements, particularly when it came to constructing the underground parking garage and the geoexchange field,” Ling says.

“This construction is also crucial to enabling the Indigenous Landscape project just to the north of that area.”

Of the trees slated for removal, 29 have trunks with a “diameter at breast height” of 30 centimetres or more – a City of Toronto bylaw requires a 3:1 replacement tree ratio for such trees, meaning each tree felled must be replaced by three new trees. With a total of 208 additional trees – in addition to the planting of thousands of other shrubs – the Landmark Project will go significantly above and beyond city requirements, Ling says.

The planting is expected to begin this summer and will continue as the project moves through the various stages of construction, landscaping and design.

The Landmark Project, which will remove cars from King’s College Circle, will see a total of 208 additional trees planted on the St. George campus (image courtesy of KPMB Architects, Michael Van Valkenburgh Associates and Urban Strategies)

Many of the trees are being salvaged, with local company Just Be Woodsy – which specializes in crafting wood products from local Toronto wood – contracted by �山ǿ�� to repurpose wood for furniture and other features around campus. Blocks of wood will also be offered to students and faculty for personal woodworking projects, ensuring that wood from the trees will be reused wherever possible.

Scott Mabury, �山ǿ��’s vice-president, operations and real estate partnerships, says removing trees from campus is never a decision �山ǿ�� takes lightly – and that every effort is made to preserve trees when possible. While some experts recommended the removal of a “regal” but leaning black walnut tree behind Knox College, for example, the university opted instead to prolong its life by cabling it to support poles.

“In the case of Landmark, I believe it’s worth it to ultimately pedestrianize the heritage core of our campus, making faculty, staff and students the privileged occupants of that space,” Mabury says.

“That’s in contrast to the current privileged occupant of that space – the car.”

Forget the lines at High Park: check out �山ǿ��'s cherry blossoms

geoff.vendeville — Fri, 21 Apr 2017 21:10:55 +0000

Forget the lines at High Park: check out �山ǿ��'s cherry blossoms

geoff.vendeville Fri, 04/21/2017 - 17:10

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There are no long lines for the cherry blossoms outside Robarts Library (photo by Geoffrey Vendeville)

Geoffrey Vendeville

Author legacy

Geoffrey Vendeville

Subheadline

Peak bloom is expected over the weekend or early next week, arborist says

Each spring, large crowds descend on High Park to behold the majesty of its many cherry blossoms – and shamelessly snap selfies.

For those who prefer quieter surroundings, �山ǿ��'s Robarts Library provides a welcome option. A path cutting across the grounds from Huron Street to Harbord Street is flanked by 70 Japanese cherry trees, also known as sakura.

The university received the trees through the Sakura Project, an initiative of the Consulate General of Japan in Toronto.

Kristen McLaughlin, a master's of museum studies student, snapping pictures of the cherry blossoms. The trees remind her of Vancouver, she says (photo by Geoffrey Vendeville)

They have flowered each year since 2005, providing students with a peaceful oasis, especially during exam season.

Diana Teal, the executive director of the High Park Nature Centre and a certified arborist, told �山ǿ�� News that the trees near Robarts will reach peak bloom April 23-25.

They are in the fifth stage in the bloom process, the “puffy white stage,” she said, adding, “That is absolutely the scientific name for it.”

“Given that it's going to be warm and a little warmer where you are because you're surrounded by buildings and concrete, you're close to peak bloom for sure,” she said.

The cherry blossoms have a relatively short blooming period. Their flowers are said to last only four-to-ten days. Last year, many cherry blossoms in Toronto didn't flower at all because of erratic weather.

The cherry blossoms cut a stark figure against the brutalist concrete architecture of Robarts (photo by Geoffrey Vendeville)

“I've seen the trees at �山ǿ��, and I know it's a beautiful little spot,” Teal said. “If you're going to have a moment with the trees and enjoy that rite of spring, going to a different park is a good option because the crowds in High Park can be overwhelming.”

Although it may be tempting to handle the trees to snap a perfect picture, Teal reminds visitors to be respectful.

“By their nature, the cherry trees can be rather fragile,” she said. “We've seen five people sitting on a limb together, and the limb falls off,” she said of the trees in High Park. “If you love the trees, treat them with respect – as you would any living thing.”

Sofia Vitorino, an ESL student visiting �山ǿ��, takes a selfie amid the cherry blossoms outside Robarts (photo by Geoffrey Vendeville)

Hager Jahim, an English major, took a study break by going for a stroll among the trees on Thursday.

“It's really pretty,” she said. “I've never seen something like this before.”

It was a campus visit to �山ǿ�� that led her to choose to study here.

“I went on a tour and I was like, 'Wow.' I was so fascinated by all the buildings, and it's such a nice campus,” she said.

The cherry blossom is meant to be a symbol of goodwill and friendship between the governments of Ontario and Japan (photo by Geoffrey Vendeville)

The trees outside Robarts aren't the only ones at the university.

Another well-kept secret among local cherry blossom-connoisseurs are the 50 trees at �山ǿ�� Scarborough between the H-Wing and Social Science building.

Avoid the lines at High Park by checking out the sakura grove at �山ǿ�� Scarborough (photo by Kristina Doyle)

�山ǿ�� helps launch an army of tree lovers

lavende4 — Mon, 24 Oct 2016 19:13:38 +0000

�山ǿ�� helps launch an army of tree lovers

lavende4 Mon, 10/24/2016 - 15:13

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Tree-lined Cabbagetown street (photo by Jay Woodworth via Flickr)

Scott Anderson

Author legacy

Scott Anderson

Topic

Subheadline

The Faculty of Forestry is teaching Torontonians how to care for one of the city’s most valuable resources – its trees

David Grant is passionate about Toronto’s trees. He’s particularly fond of the majestic silver maple that stood outside his Cabbagetown home. But he had never thought much about how to care for it – until three years ago when the ice storm hit.

Surveying the downed branches in his own yard and along his street, Grant wondered about the millions of other trees across Toronto. Did his fellow homeowners know how to care for them in the wake of such a damaging event?

Soon after, Grant met Sandy Smith, a professor in the Faculty of Forestry, who had an interesting idea: students from Smith’s graduate class in urban forest conservation would work with Grant and other Cabbagetown residents to devise a long-term plan for the care of their community’s trees. Residents themselves could then follow the preservation plan.

“It was like a dream come true,” says Grant.

Now, he is looking to replicate the success of Cabbagetown Releaf – the non-profit association he founded to carry out the plan – in other communities. And, once again, he has enlisted Smith’s help.

Early in October, Smith and a colleague, Danijela Puric-Mladenovic, spent the day training about 25 Torontonians in the basics of forest management at an event organized by Cabbagetown Releaf. The hope is that these newly trained “citizen foresters” will fan out across the city and set up urban forestry groups in their own communities.

“This is David’s vision to educate and build awareness, so the average person knows about the health of trees,” says Smith. “Governments can’t afford all the work that needs to be done.”

Smith likens “citizen foresters” to “citizen scientists,” a movement that has gained steam in recent years to involve members of the public in science projects, ranging from counting butterflies to tracking bird migration. A citizen scientist group in Toronto monitors the health of the Rouge River in Scarborough. Citizen foresters would do something similar for the city’s trees.

The effort aims to protect a valuable investment. A 2014 report by the TD Bank Group estimates that Toronto’s 10 million trees are worth about $700 each, or $7 billion in total. According to the report, the urban forest provides Toronto residents with more than $80 million worth of environmental benefits and cost savings each year, or about $125 per household.

These benefits include improved air quality, better storm water management, reduced flooding, and cooler homes and businesses. Trees also absorb carbon dioxide, which helps to slow climate warming. The study didn’t put a dollar value on less tangible benefits, such as the enjoyment people get from parks, but Grant sees these as no less important.

“Nature helps people de-stress,” he says

Learn more about Smith's urban forestry efforts

Looking ahead, Grant has no shortage of ideas about how to expand the program. He wants to encourage community members to grow trees from seeds and then have an annual seedling giveaway. He thinks there’s good potential for working with schools to have students grow seedlings and share these with neighbourhoods that need more trees.

He hopes that one day Toronto might be home to a small army of citizen foresters tending to the urban canopy.

“We need to protect what we have,” says Grant, “and to start doing things for future generations.”

Learn more about the Citizen Foresters

(This story originally ran in �山ǿ�� Magazine)

Autumn in the Rouge: changing colours is just the start, �山ǿ�� experts say

ullahnor — Fri, 21 Oct 2016 16:01:26 +0000

Autumn in the Rouge: changing colours is just the start, �山ǿ�� experts say

ullahnor Fri, 10/21/2016 - 12:01

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Leaves are now bright hues of red, orange and yellow in Rouge Park (photo by Ken Jones)

Don Campbell

Author legacy

Don Campbell

Topic

City & Culture

UTSC

University of Toronto Scarborough

Fall Colours

Rouge National Urban Park

Subheadline

Exploring the Rouge during autumn? There’s more than just changing colours

It’s that time of the year again. There’s a chill in the air, the days are getting shorter, and the city is painted with a cascade of changing autumn colours.

Perhaps in no other place in Toronto are these changes more evident than the Rouge National Urban Park. With its accessible trails and abundant biodiversity, it’s a popular spot for nature walkers and bird spotters alike, especially in the fall.

The University of Toronto Scarborough is the primary research and education partner with Parks Canada, with experts who use the Rouge to conduct research and take class trips to explore the many species that live in the park. Some of those researchers shared insights on what’s taking place in the park throughout autumn.

The park is unique because it’s situated in a transition zone between the Carolinian forest and northern forests, and also happens to be located in Canada’s largest city, notes Associate Professor Marc Cadotte, an expert on urban forest conservation and biology at �山ǿ�� Scarborough.

“The Rouge is unique because of its high diversity and unique combination of species,” he says.

That diversity can be experienced with a quick walk around the park, he adds. If you’re near the Glen Rouge campground, you will see plenty of maple, oak and hickory forests but as you move to more hilly terrain, you will start to see spruce, pine and cedar. This also means the animals and birds will be different from one location to the next.

Associate Professor Marc Cadotte in Rouge National Urban Park (photo by Ken Jones)

In the park, you’ll notice different colours in the leaves because, as Cadotte points out, there’s considerable variation in leaf colour even within the same species of trees.

“The colours are produced by the chemistry of the leaves," he says. "They’re typically green in the spring and summer because of chlorophyll, which drives photosynthesis.

“As the days begin to shorten, trees prepare for the winter by drawing in the important chemicals of the leaves. What’s left behind can be quite colourful.”

The reason they eventually fall and die is that even though leaves are a food source for a plant, once winter rolls around they become a burden. Cadotte says if you’re out for a stroll, you may also notice that some leaves of some plants remain green and don’t fall. That’s because they’re either invasive, like the garlic mustard plant, or they’re evergreen trees like pine that have evolved in harsher climates.

Morning is a great time to see insects, notes Cadotte. The most obvious will be the monarch butterfly, which is preparing for its long migration south to Mexico. There will also be plenty of woolly bear caterpillars, which are preparing for their long hibernation for the winter.

“During autumn mornings, you’re more likely to see insects resting on bark or the side of trees. You can walk right up to them, and they won’t take off because they need to warm up before they can move,” he says.

Mornings are also a great time to see mammals being active, says Rudy Boonstra, an ecology professor who studies animal behaviour at �山ǿ�� Scarborough.

“The best time is either early morning or right before dusk when human activity is low,” he says.

There’s a whole range of animals to see throughout the Rouge, including cottontail rabbits, raccoons, squirrels, chipmunks, woodchucks, foxes, coyotes, white-tailed deer, striped skunks, and even mink along the shores of Highland Creek and the Rouge River.

Some hibernators, like chipmunks, spend all fall storing food in an underground cache. They will wake up every few weeks in winter to replenish body stores before going back in hibernation. Others, like woodchucks, store food internally in the form of fat, he adds. They also wake up every few weeks during the winter but replenish their needs from their fat stores. Both species will lower their metabolism to a few degrees above zero-degrees Celsius in order to conserve energy.

People stroll through Rouge National Urban Park (photo by Ken Jones)

Other mammals prefer the “sit and take it” approach, says Boonstra. Animals like white-tailed deer, red fox, red squirrels, grey squirrels and raccoons do not hibernate. Some remain active and can be seen, while others, like the raccoon and skunk, become inactive in a burrow or tree hollow and may reduce their body temperature slightly

He adds that male deer in rut, also called bucks, can be dangerous from October to early November since it’s the mating season.

“If males have a look where they aren’t afraid or are eyeing you up, it’s a good idea to stay away,” he says. “It’s very rare for them to charge, but it does happen… just check out YouTube.”

Boonstra adds that the City of Toronto’s Biodiversity in the City series is a great resource for those wondering what mammals and birds they can see along Highland Creek and the Rouge River.

One of the more obvious signs of autumn is migrating birds, adds Associate Professor Jason Weir, who does research on the biodiversity of new world birds at �山ǿ�� Scarborough.

“There are big wetlands where the Rouge empties into Lake Ontario so you will see all sorts of birds,” he says.

At this time of the year birds, many of which live in pairs or small groups during the summer, aggregate in flocks in order to migrate south. In the forests along the Rouge there are songbirds such as warblers, sparrows and blue jays that can be seen, he says.

On recent class trips, Weir says, he’s come across wood ducks, gadwalls and northern shovelers as well as great egrets and caspian terns in the wetlands.

Walking through the Rouge, you may also come across fish like migrating chinook salmon and rainbow trout that have been stocked and are now naturalized in the area, says Nicholas Mandrak, an associate professor at �山ǿ�� Scarborough who is an expert on freshwater fish.

“There’s a good chance of seeing these species, particularly after a rainfall, which triggers them to swim upstream,” Mandrak says.

�山ǿ�� Forestry expert warns of dry summer's effect on trees this year

ullahnor — Thu, 01 Sep 2016 20:21:08 +0000

�山ǿ�� Forestry expert warns of dry summer's effect on trees this year ullahnor Thu, 09/01/2016 - 16:21

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With a dry summer, leaves have begun yellowing and browning sooner (Photo by Noreen Ahmed-Ullah)

Noreen Ahmed-Ullah

Author legacy

Noreen Ahmed-Ullah

Topic

Subheadline

“Water your trees”: Sandy Smith tells Toronto homeowners

Water your trees.

That's the message that University of Toronto Forestry professor Sandy Smith wants Toronto homeowners to heed this year, after a hot dry summer. Trees are in such bad shape that Smith thinks the city of Toronto needs to put out an alert advising residents to water their trees and cautioning them that the dry spell can lead to dying branches falling off, as happened when a large branch fell in Trinity Bellwoods Park in June, killing a man below.

�山ǿ�� News spoke to Smith about what is taking place both above and below ground and how it’s manifesting itself into earlier than normal yellowing and browning leaves.

___________________________________________________________________________________________________________________________________________________________________

How is the drought affecting trees?

These hot dry summers have huge impact on trees. It’s not as catastrophic as an ice storm, but it’s basically the same over time. It’s a slow burn, not a fast burn. And drought can affect trees up to five even ten years later.

The trees where the owner has watered or if there’s irrigation, those trees are doing much better. But the other trees are really struggling. They’re starting to shut down. When it’s really dry, the trees close the pores of stomata in their leaves because they can’t lose water. The leaves start to shut down because there’s no energy being stored there. So you start to see die back and no nutrients being shunted down to the roots. The roots start dying back because they’re not getting water. The more peripheral the roots, those that are way out there, they start to die back, which produces a domino effect back up to the top of the tree. So next year you’ll see dead branches where the tree shut down because it’s lost part of its roots.

Without water, the tree is forced to shrink back on top and bottom. The roots die off. The branches die off. They stop sending sap there. The living parts die. So what you’re left with, you’ll see trees with just branches with nothing on them. Next year, you will see more dead branches than you would see in a normal year.

You can’t see below ground, but it’s happening below ground as well. If you look at the roots, you’d see the same thing.

What are the signs that we can see?

I think you can see it through wilting and yellowing of the leaves and browning. You’ll start to see leaf burn, so the edges of the leaves and the tips of the leaves start to turn yellow and then brown-red. Yellow means their dying. Brown-red means they’re dead because of all of the chlorophyll being pulled out or being broken down. The longer the drought carries on, the complete leaf dies, not just the edges and tips. Then, the whole branch dies. So this summer you can see the yellow browning.

What trees are most affected?

The horse chestnuts are going through it. The oaks don’t look so good. When you have a couple of years of really wet moist conditions and all of a sudden a dry summer, this is really hard for trees.

Horse chestnut is a European tree that was planted a lot in the ‘20s, ‘30s and ‘40s. Those are larger trees that are always susceptible to hot and dry conditions. They’re the ones that you see the first signs. The others that are not doing well are ash. In a summer like this, they’re doubling their rate of mortality. Next summer you’ll see even more dead ash. Most of the ash will be dead and almost dead because it was a warm winter and the Emerald ash borer did really well feeding on them all winter, longer than it should have. And now it’s a hot dry summer, which means the trees can’t defend themselves. They don’t have enough sap to pull up and drown these beetles. Next year the ash will be in particularly bad shape with lots of dead branches, Bad shape meaning dying and dead with dead braches and maybe whole trees standing dead.

So what can we do?

The one thing you can do is water your tree. In a summer like this, it’s almost essential. Wherever prossible, the city needs to increase its watering program. The city should also be sending out an alert, raising awareness for everyone. The city should put alerts out for people with trees on their property that drought creates stress on their trees, and they need to look at their trees, not just assume they’re always going to stand there like the hydro pole. They are living things. They are living entities that need water.

Next year, city parks and street trees should be checked. The city needs to increase its vigilance, surveillance of this, to see what the impact of the drought was. After a hot dry summer you should be alerted to potential risks out there like dead branches and trees dropping branches on people.

Spruced up: �山ǿ�� biologist uses drones to help build a better tree

lavende4 — Fri, 26 Aug 2016 13:20:46 +0000

Spruced up: �山ǿ�� biologist uses drones to help build a better tree

lavende4 Fri, 08/26/2016 - 09:20

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White Spruce cones (Photo by MyLoupe/UIG Via Getty Images)

Carla DeMarco

Author legacy

Carla DeMarco

Topic

Ingo Ensminger, a biologist at University of Toronto Mississauga, is using a drone to help breed better spruce trees.

Ensminger and his collaborators are working on a suite of modern genomic resources to improve tree breeding and selection, using large white spruce progeny trials established in Quebec and Ontario by the Canadian Forest Service (CFS). This progeny data represents 20 years of tree-breeding research, where scientists have selected 2,000 different genetic lines of spruce seedlings; they expect to find spruce seedlings among those lines that will efficiently adapt to environmental stresses.

Along with his CFS collaborator Nathalie Isabel, and in association with industry partner PrecisionHawk, Ensminger will use a drone carrying optical sensors for leaf-spectral measurements that will ultimately help distinguish the best genetic lines based on their “optical fingerprint.” The project is funded by Ontario Genomics.

“The main idea behind the optical fingerprint is the fact that plants constantly interact with their ever-changing environment,” says Ensminger (left). “This involves adjustments in pigments that are responsible for the colour of the leaf. These adjustments take place within minutes and over the course of the season in order to mitigate stress and maximize the yield of photosynthesis. Adjustments in leaf pigments accurately reflect the fitness of a plant.”

His team will use samples of seedlings from the ground to assess fitness, using existing tests. After measuring the optical properties of these leaves, they will compare findings with data collected by the drone – data that is captured in a fraction of the time and on a much larger scale. The ground data, he notes, will help the team better understand the drone data, and calibrate growth models accordingly.

“The resolution of the drone sensor will be good enough to distinguish individual seedlings,” Ensminger says. “We think we can assess performance of individual plants and quickly identify the most robust genetic lines during a short drone flight from fields with several thousand individuals.”

The investment by Ontario Genomics’ Pre-Commercialization Business Development Fund will support deployment of a software application created by PrecisionHawk that will eventually become available to breeders and forest managers through the Algorithm Marketplace.

“This will be a software tool made for users in the breeding and forest management industry,” says Ensminger.

“While the users are not specialists in remote sensing and plant physiology, this software will help them analyze drone data and determine the fitness of individual trees or entire forest stands. They’ll be able to quickly assess when trees are water stressed or when the growing season ends, so they can adjust their management practices accordingly.”