Climate change-triggered weather wreaks havoc in Arboretum

by | Nov 28, 2014 | News

Clare Jenkins
Environment Reporter

Climate change is here and it’s right on campus.

The Humber Arboretum is home to more than 1,700 species of plants and animals, has over six kilometres of walking trails and plays host to ecologically friendly team building exercises, wedding photography, mood walks and nature camps.

The Arboretum has seen the effects of climate change on its tree population, said Jimmy Vincent, coordinator at the Centre for Urban Ecology in the Arb and an outdoor education instructor who plans different activities like outdoor education programs and nature camps.

“We’ve had a lot of trees damaged,” he said. “Especially in extreme weather like last year’s ice storm. That’s a direct correlation with climate change. You’re starting to see more natural disasters move in. It came in and took down hundreds of trees in the Arboretum.

“On top of that, the flood last summer washed out all of our trails. We see climate change having an effect on the use of the natural area.”

The Centre for Urban Ecology partnered with the Association for Canadian Educational Resources (ACER) to monitor various tree species in the Arboretum and how they are being affected by climate change.

“ACER has started monitoring, called tree caching,” Vincent said. “They’ve got trees with QR (Quick Response) codes on them. So anyone with a smartphone can scan them and learn what species the tree is, how old it is, how tall it is, how much carbon that species is storing and how much CO2 it’s taking in. It will also show you all the trees in a local area.

“We are also concerned about seedling regeneration,” Vincent said. “Invasive plant species like garlic mustard have started moving into our forest.”

Mustard seed has a toxin in it that affects the soil and roots of trees, which can kill them and lower the amount of seedling regeneration.

“We have been removing garlic mustard but we aren’t seeing the regeneration that we’d like to see and that could definitely be climate change related,” he said.

Floods and ice storms aren’t the only thing effecting the tree population in the Arb. Changes in weather are causing new species of insects to migrate to Toronto from the southern parts of Ontario and beyond.

“Invasive species and insects are able to thrive in this environment because it’s getting warmer and maybe if we weren’t going through climate change, that wouldn’t be able to happen because it wouldn’t be an ideal habitat for them,” Vincent said.

One of the species of insects that is particularly taking a toll on the Arboretum is the emerald ash borer, a green beetle that is native to Asia and eastern Russia. The beetle, which is particularly destructive to ash trees, arrived in North America in 2002 when it was accidentally brought over in a shipping crate.

“We have ash trees in our forest that have been killed by it but we do have a couple of trees that are being treated in hopes that it will continue on growing,” Vincent said.

Katie Howard, 24, is a graduate from the Environmental Studies program at York University and has written for the environmental magazine Corporate Knights.

“Climate change is definitely having an effect on tree populations, especially in the west. Trees are dying younger and younger,” Howard said. “It’s sad that maple trees have started to be affected.”

The Centre for Urban Ecology also has a research project going on to help save the endangered butternut tree. The butternut tree has recently been affected by the butternut blight, a canker or area of dead tissue that grows on the tree. The Arboretum has a butternut on site that is in decline.

“What we’re doing is grafting the butternut tree to a black walnut root stock,” said Vincent. “They are similar species and the idea is the butternut trees will be more resistant. They’ve had great success.”

Shannon MacAskill, 20, an Early Childhood Education student at Humber, said she sees the benefits of outdoor education.

“I think kids need to get outside and experience nature,” said MacAskill who works at the Humber College Child Care Centre at North campus.

“I think the Arboretum is a great place to take kids to learn about plants and animals,” she said. “The fact we’re losing trees is really sad. They can teach us so much. They look so nice in the fall and give people so much joy. I think kids are going to miss out if we lose the trees.”