The harsh winter eastern Canada has suffered will have come as a shock to invasive plants and insects that have become used to years of mild temperatures.

Biologists at the Royal Botanical Gardens are hopeful the unusual conditions have a positive effect on the area’s natural environment.

 The benefit of this winter, says Tys Theysmeyer, the RBG's head of Natural Lands​, is how hard the ice and cold hit plants that are not native to the area.

“The species that have been invading North America will be knocked back.”  

Some plant species he's hope to see suffer from the winter are the multiflora rose, as well as the honeysuckle, the buckthorn and the common privet.

Theysmeyer said it's a good thing, "generally, if they are plants (that) don’t fit into the system.” Invasive species typically crowd out native species and as such they can have a negative effect on the natural environment.

Invasive Species in Ontario

Theysmeyer also said the winter may also have knocked back pesky insect life that has been invasive and destructive, cutting populations of species like the gypsy moth, the marmorated stink bug, the emerald ash borer as well as many introduced breeds of ladybugs that come from across the ocean.

Since 2009, the city has been struggling to get rid of the ash borer, which has been destroying thousands of local ash trees. Over the next 10 years, the city plans to chop down all of its nearly 23,000 ash trees to remedy the infestation.

Plants, insects and animals typically invade two ways: they can be imported and introduced into the environment. For example, an Asian tree or flower being planted in North America. Or they can naturally crawl north as the climate warms.

Ontario has had years of milder winters, which has allowed these plants and insect to slowly creep up from below the border and survive. However, now that the cold has hit the area so hard, they will be fended off.

"Anything alive, if you're not adapted to withstand the cold weather... you're dead," said Theysmeyer.

Plants and animals starting to come back

Despite the on-going cold, “some plants have started to appear... and animals have popped out of hibernation,” said Theysmeyer. However birds have been a little delayed in their return. “Last year this time we had all of them.”

Water birds especially will be delayed because they need open water in order to land, but a lot of the water is still frozen.

A good sign, said Theysmeyer, is the return of the Red-winged Blackbird. “They are usually our sign for spring.” Not the robin.

“Nobody’s seen a chipmunk yet.”

One concern on the minds of the RBG is the survival of some wetlands animals like frogs and turtles. “They have been pinned down to smaller areas of the marsh,” said Theysmeyer and with the extreme freeze they could have been dramatically affected.

“All will be revealed when the ice melts.”