Invasive groups control unwelcome plants and animals on the peninsula

Jun 2, 2021

Last summer, an orange hawkweed infestation was reported on Tsalteshi Trails. In Homer, orange hawkweed is everywhere.
Credit Wikimedia Commons

While the Kenai Peninsula is relatively lucky that the ecosystems here are fairly intact, there are still a handful of invasive species making their way into the streams, fields and gardens here. In recent years, that’s accelerated due to climate change and people intentionally or unintentionally bringing in new species.

For about the last 15 years, the Kenai Peninsula Cooperative Invasive Species Management Area has primarily focused on plants. In fact, that was previously in its name — it was called the Kenai Cooperative Weed Management Area until this last December, when the group changed its name.

Katherine Schake, the coordinator for invasive species program through the Homer Soil and Water Conservation District, said  their work is now open to all kinds of invasive species — including animals.

"Some people will plant an ornamental in their yard and not realize it can jump the fence and take over the salmon stream," Schake said. "Or there’s people transporting fish from one lake to another, which is illegal and not allowed, but it still gets done sometimes."

The Alaska Department of Fish and Game, the U.S. Fish and Wildlife Service, and the Kenai Watershed Forum are handling work on invasive species like northern pike on the peninsula, while much of the work that the Soil and Water Conservation District handles is still invasive plants. However, the groups do work together when the opportunity arises, Schake said.

For instance, the Kenai Watershed Forum and the Soil and Water Conservation District are working together on controlling orange hawkweed on the central Kenai Peninsula. Last summer, an infestation was reported on the Tsalteshi Trails, and the Kenai Watershed Forum went out to treat it with herbicide.

Orange hawkweed looks a little like orange dandelions and grows in clumps. When it’s cut or torn up, it actually grows more, and it can release a toxin that inhibits other plants from growing up. Schake said it’s usually treated with herbicide because the entire root has to be torn up.

In Homer, the weed is everywhere. But in the central peninsula, the infestation is still isolated enough that it could be treated and controlled, Schake said.

"As we get further from Homer toward the central peninsula, we manage and respond to any other orange hawkweeds that have shown up so far that are in public lands or are in DOT right-of-ways, along the highways, or even on borough roads," she said. We’re assisting with eradication there. One of the things that’s most important above all with invasive species is reporting. We rely on the public to let us know when they find an invasive species."

Generally, the invasiveness of a particular weed is rated based on how it reproduces, spreads, and displaces other native species. If it’s relatively low risk, like dandelions, it’s not a high priority for treatment. However, high risk species like orange hawkweed are important to treat. Another one is mayday trees, also called chokecherry or European bird cherry. The trees are pretty, smell sweet, and attract birds, but they also spread and can displace other species.

Last summer, the Soil and Water Conservation District and the Kenai Watershed Forum worked together with volunteers to survey how many of the mayday trees there were on the peninsula. Previously, the local word had been that they weren’t invasive on the peninsula, only in Anchorage. Last summer’s survey showed that wasn’t true, and Schake says the organizations are planning work this year to take out a number of them.

Often, one thing the groups struggle with is outreach and awareness, she said. But that wasn’t true with the mayday tree case.

"They have a great scent, they attract the birds, they’re beautiful, but they have become so aggressive and are outcompeting native vegetation for moose and also becoming a pain for people to manage in their laws, that we didn’t have to do much of that outreach because people talked amongst themselves and have seen firsthand what it’s doing," Schake said.

This summer, the governor has declared an Alaska Invasive Species Awareness Week starting on June 13. The Cooperative Invasive Species Management Area is planning a number of community weed pulls that week, and Schake says more details will be published on the group’s website, kenaiinvasives.org. That website also has more information about the invasive species documented on the peninsula and how to treat or manage them.