Pretty but pesky: Alaskans wage war on invasive plants

Volunteers work in Anchorage’s Tikishla Park on Aug. 19 to pull out invasive chokecherry trees, also known as European bird cherry trees. The volunteers were participating in a “weed smackdown” that was one in a series held to remove invasive plants. (Photo by Yereth Rosen/Alaska Beacon)

It wasn’t long ago when Anchorage homeowners eagerly planted the blossoming European bird cherry trees. The trees’ white flower buds were a great way to brighten up their lawns. On Aug. 19, an army of volunteers converged on a local park to pull them out.

Members of the Alaska Cooperative Invasive Species Management Area were the ones to organize the invasive plant “weed smackdown” at Tikishla Park. Invasive plants are plants that are not native to the ecosystems they are found in. These plants compete with native vegetation that wildlife relies on for their habitats and food, which is why several groups in Alaska are fighting them. 

Around 62 volunteers had registered for the event and all the trees they removed would be chopped up for mulch. This event isn’t the first or last of the cooperative’s events.

Numerous non-native plants have found their way into Alaska. Plants such as orange hawkweed, thistle and knotweed are some other priority species for those trying to control the invasives. 

The Alaska Invasive Species Partnership is one group that focuses on the problem and ways to manage it. The partnership, a volunteer organization, has been around for about 20 years. 

The partnership isn’t the only group doing something about these invasive species. “A lot of the work being done, especially with invasive plants, is being done at the local level with Soil and Water Conservation Districts,” said Gino Graziano, an invasive plant specialist with the University of Alaska Fairbanks’ Cooperative Extension Service

A top priority is the removal of the European bird cherry, also known as the chokecherry. According to experts, the trees were introduced in the 1950s. The trees were ornamental and were hardy enough to survive in Alaska.

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A sign posted along Anchorage’s Chester Creek trail on Aug. 19 explains why European bird cherry trees were being removed during that day’s “weed smackdown” at Tikishla Park. (Photo by Yereth Rosen/Alaska Beacon)

“Obviously, they’re pretty and moose typically don’t eat them, which is why we planted them for a long time,” said Graziano, who is an Alaska Invasive Species Partnership board member.

It wasn’t until the early 2000s that people started to realize that it was a mistake to introduce them to Alaska, experts say.  

Despite their pleasing appearance, these trees do more harm than good.

When the trees get out into our forests, they tend to spread with their roots and with their branches, as well as the seeds, and make these kinds of dense shades that keep a lot of other plants from growing in those areas. These create a new shade layer, it seems like, so we usually see things like ferns and cranberries and currants, that would normally be on the forest floor, kind of disappear,” Graziano said. 

The problem extends beyond Anchorage. “They’re there and they’re present,” Graziano said. “There are communities all over the state that, as they’ve started realizing, ‘Oh, this is what’s happening in Anchorage, Talkeetna, and other communities in Southcentral Alaska,’ they start looking and then they’re noticing the tree, too.”

In addition to their effects on the forest habitat, invasive plants can harm Alaska wildlife.

That harm can be extreme in the case of the European bird cherry. Every year, there are a few cases of moose dying after being poisoned by that plant, said Dr. Kimberlee Beckmen, an Alaska Department of Fish and Game veterinarian.

“Browsing on the leaves under certain conditions kills moose rapidly by cyanide poisoning,” Beckmen said.

The knotweed, found in Juneau, is another non-native plant that is a high priority for managers. John Hudson, a restoration biologist, said that he isn’t sure how the knotweed placed its roots in Southeast Alaska. On an invasive plant ranking system created by biologists, land managers, and weed scientists across the state the knotweed ranks at the top with the most potential invasiveness.

“It’s the highest-ranking non-native invasive plant in the state. It does not produce seed so it relies on humans to spread itself,” Hudson said. 

That is how the knotweed and other invasive plants find their way into Alaska soils and forests; with the help of people. “Today many highly invasive plants have made it to the state and are rapidly spreading by taking advantage of the human footprint, like roads and other areas where humans have disturbed soil and natural plant communities, to build parking lots, businesses, schools and homes,” Hudson said.

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Gino Graziano pulls some cut-down European chokecherry trees from the woods at Anchorage’s Tikishla Park on Aug. 19. Graziano, an invasive species specialist with the University of Alaska Fairbanks’ Cooperative Extension Service, helped organize the “weed smackdown” at the park. The invasive trees, once prized as garden ornamentals, have spread into various wooded areas, including this area by Anchorage’s Chester Creek, and they are crowding out native vegetation. (Photo by Yereth Rosen/Alaska Beacon)

When assisting in the efforts to manage invasive plant species, the most important thing Alaskans can do is become educated. Helpful information and resources from the Department of Fish and Game, AKISP, and other organizations are available online.

“A lot of the progress that we make on invasive species really comes about by the participation from the public, in letting us know about where they’re finding invasive weeds, and, when they find them on their property, that they take the initiative to manage them,” Graziano said. “If we can continue to try to work towards managing the plants and being smart about it, hopefully, we will have fewer and fewer of them.”

Alaska Beacon is part of States Newsroom, a network of news bureaus supported by grants and a coalition of donors as a 501c(3) public charity. Alaska Beacon maintains editorial independence. Contact Editor Andrew Kitchenman for questions: Follow Alaska Beacon on Facebook and Twitter.

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