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NORTHWEST TERRITORIES
Warmer temperatures and increased development has biologists worried about new species of plants and animals invading the Northwest Territories.

Yellow and white sweet clover is taking over roadsides in the Northwest Territories. The invasive species is used as cattle feed on farms, which is now attracting bison to roadways. - photo courtesy of Suzanne Carriere

Suzanne Carriere, wildlife biologist with the Department of Environment and Natural Resources (ENR), said problems with alien plant species have already begun.

Yellow and white sweet clover, a European plant often used as feed for cattle on farms in southern Canada, are taking over habitat formerly occupied by fireweed.

"What they're doing is they're displacing our beautiful native fireweed," Carriere said. "So when people go along the road, instead of seeing that purple, pink roadside, they're seeing that washed out white and yellow sweet clover."

Drivers who were completely unaware their vehicles carried plant debris probably introduced sweet clover to the territory.

"It will hitch a ride on a car and also the tractors that are used to cut the edges of the roads," Carriere said. "It's all over now. There's not much we can do in terms of getting rid of it."

The plant is also attracting bison and other wildlife to the area where it grows, which is typically along the sides of roads, Carriere said.

"People think it smells sweet and nice, but also it's a cattle feed," she said. "So you get bison feeding on it and some of the wildlife feeding on it, so it's not good for them because feeding on the side of the road is not the best idea."

There were 16 accidents involving bison on the territory's roads in 2012, according to the Department of Transportation. So far in 2013, there have been four.

Carriere said warmer winters are to blame for the plant's distribution. Sweet clover is now found from the Alberta border all the way to Inuvik.

Freezing temperatures used to prevent the spread of new species that couldn't handle the cold, Carriere said. Now, lengthy cold snaps are unusual.

"I mean a good two weeks of minus 40, that's what we want to see in terms of cleaning ourselves of any alien species," she said. "But it's getting rarer."

There were 116 alien plant species in the NWT in 2010, according to information from ENR.

"Our shield is falling apart," Carriere said.

The GNWT also has plans to create and improve the territory's roads to allow for further development over the next decade, which Carriere said could further increase the range of invading plants and animals.

"It's opening more of the landscape," she said. "It's a concern in terms of alien invasive species for sure. We have to be aware of that."

The same is true for lakes and rivers in the NWT, which are especially vulnerable to invasive species such as plants or mussels that can wipe out ecosystems.

"It's so easy to bring something new into a lake," Carriere said.

But, she added, there are steps people can take to prevent species from being carried into different regions, such as thoroughly cleaning boats and vehicles before leaving an area.

"I think we can have both roads and have no invasive aliens," she said. "We don't have to have more invasive alien species because of roads. We have to do our part so there is no cause and effect."

Carriere said 15 minutes of cleaning will help make sure no plants or insects are unintentionally carried into the territory or other regions of the NWT.

People should also be careful when planting trees or other plants from the south in their gardens. The birch leafminer, a member of the sawfly family that is responsible for turning birch leaves brown, was introduced to the territory in the 1990s.

"It hitched a ride on people's trees," Carriere said.

Plants and insects aren't the only ones taking advantage of warmer temperatures and increased development, Carriere said.

White-tailed deer have been moving into the territory since the 1940s, according to ENR.

"The cause of all this is our climate is changing, we're providing more habitat for them," she said. "They're moving north because they can."

Carriere said alien species are classified as low, medium or high, depending on factors such as how difficult they are to eradicate. So far, there are no highly invasive species in the territory, Carriere said.

Getting people to report what they believe is an alien plant or animal to ENR is vital to keeping invaders under control, she said.

"If they see something different, sometimes if it's a small patch, it's easy to get rid of," she said.

Carriere said ENR started a Facebook page titled NWT Species to give people a place to post photos and exchange information. She said ENR staff monitor the page and usually respond to questions within 24 hours. Carriere said the page has become a critical tool.

"It's really helpful when people send photos and ask questions," she said.

While protecting NWT lakes is now at the top of the priority list, Carriere said staff working on the

NWT Alien Species Project, which began in 2006, are planning to conduct a survey on invasive plants along the territory's roadways next year.

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