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By MARJORIE CLARK
Daily News Staff Writer
According to the U.S. Forest Service, invasive weed species are becoming more prevalent in Southeast Alaska, including Revillagigedo Island. The more prevalent species are orange hawkweed and Japanese knotweed.
Both weeds are spreading their way across the island, taking over habitats naturally meant for salmonberry, indigenous wildflowers and second-growth trees. According to the USFS, the problem with the takeover includes displacing the variety of native plant life, which in turn harms the ecosystem around it.
"Anytime you have just one plant species, it lowers biodiversity," said Patricia Krosse, the Forest Service invasive species and air quality program manager for the Alaska region. "You need different plants for it to be a good habitat for bugs, nutrient input into the water and structure along the stream system."
According to Krosse, the Tongass National Forest currently has orange hawkweed and Japanese knotweed. The agency has tried various methods to remove the weeds and hasn’t been totally successful, though it continues to work on it.
"It’s not nearly as bad as along the road systems, but [they] are the corridor to the forest," she said. "It is really important, with the Forest Service, to work with the communities on their strategies, as well as the [Department of Transportation], to keep the populations within the city limits at bay. At very least, contain them."
The stated mission of the Forest Service is "to provide the greatest amount of good for the greatest amount of people in the long run" and, according to Krosse, that includes keeping the forest as natural as possible. The agency monitors the border between its land and the borough, located at Revilla Road, to watch for invasive weeds creeping onto federal land.
"We take a look at that area and we’re gonna see, is there any hawkweed coming on our side of the border?" she said. "That would be the place we would treat it if we chose to, so it wouldn’t just keep going down the road."
A weed is defined as any plant that grows where it is not wanted. Krosse acknowledged that some people might enjoy the bright orange color of the hawkweed’s bloom and its showy nature, and therefore not consider it a "weed" at all.
"The city may want ‘introduced’ plants... but hopefully they are things we can control and maintain in our horticulture environments," Krosse said. "Talk to your neighbors. Be considerate and responsible and at least try to contain it within your yard" if you choose to introduce a non-native species.
The orange hawkweed has a distinctive orange flower that blooms during May and June, depending on the weather. The plant spreads mostly through its root system, similar to the way strawberries and crabgrass spread, and creates a "mat" of vegetation. After the orange flower disappears, hawkweed produces a puffball of seeds, as a dandelion does after its yellow flower dies, creating hundreds of opportunities for the plant to be introduced into new soil and create new colonies.
Hawkweed is particularly difficult for the Forest Service because it tolerates shady areas and is not confined to sunny and rocky road shoulders.
Krosse suspects one of the ways hawkweed traveled to Ketchikan is through packets of wildflower seeds. Some packets say "Alaska wildflowers" but they might contain seeds not native to Alaska, such as hawkweed, she said.
Japanese knotweed, also known as "fake bamboo," is a perennial, springing up from the ground every year. It can grow to be 10 feet tall, with a thick hollow stem, and spreads through its root system. According to Forest Service literature, the knotweed forms dense colonies and will overcome other plants in the area. It grows quickly along streambeds and can block the stream’s flow, diminishing the ability for salmon to spawn and blocking the stream from other wildlife.
The Forest Service has outlined a few ways to combat hawkweed on private property, which include digging up the plant by its roots and removing it, covering it with tarp to "bake" it and applying chemical treatment. Krosse recommended an herbicide called Milestone, but said Roundup would also work.
"Chemicals that are out for commercial use have been through a lot of testing and are really pretty rigorously controlled. Using it on a spot basis, squirting the actual plant, is the best, and most cost-effective and efficient way, because you will get rid of the plants in one to two years," Krosse said.
She said burning the weeds is an effective way to dispose of them; she burns the weeds from her property in a burn barrel. The City of Ketchikan Solid Waste Facility can incinerate green waste from residents, if it is disclosed that the waste contains invasive weeds. Senior landfill operator Larry Karles said the cost of incineration is 26 cents per pound plus a fuel surcharge, with a minimum charge of $52.
Along the North Tongass Highway road construction site, between Ward Cove and Refuge Cove, DOT is eradicating a colony of knotwood. The road project has a budget of $12 million and $100,000 is allocated for the management of the invasive plant to prevent its spread to nearby areas.
According to DOT Public Information Officer Jeremy Woodrow, the North Tongass Highway construction crews are digging up the knotweed and burying it within the same project 4 feet below the surface, then covering it with shot rock. It is then paved over the top to prevent the plant from finding its way back to the surface. They call the process "capping."
"We’ve been doing it about seven or eight years here," Woodrow said. "We haven’t seen any negative returns for that type of process."
Woodrow said DOT regulations require them to remove the species only when DOT is doing "earth-disturbing activities." This means that when they are widening a road or doing something that requires them to dig up the shoulder, DOT creates a plan to handle the unwanted plants. Cost and project scope can also inhibit the removal of the invasive plants. In those cases, DOT works with the site contractor to have the species incinerated or moved to a landfill where it will be capped. The environmental plan includes a sanitization plan for vehicles and construction equipment to prevent tracking the seeds and roots to other locations.
"We have to prevent the spread of them, so one way or another we will limit that species from being able to grow back in that same area, or in another area," Woodrow said.
If the project is a simple repaving, painting or does not go beyond the pavement, DOT will not disturb the shoulder and would not remove invasive plants.
A big portion of preventing the spread of the invasive plants within the community is education and awareness, Krosse said. She has worked with the Ketchikan Garden Club to help participants understand the ramifications of unintentional plant selection and preparing for the garden sale. She said they have come a long way in the past 20 years in understanding the effects of plant selection and the impact it can have on neighbors.
Maria Pointer is a long-time resident of Pennock Island and works to educate communities and organizations about the dangers of invasive weeds. She received her first dose of information at a conference in November 2010. Since then she has provided countless presentations and handouts to provide information at Ketchikan City Council meetings, garden club gatherings and statewide conventions.
"It’s amazing how patient these agencies are with communities and groups, trying to keep the work on a volunteer basis and supported with grants," Pointer said. "They are not requiring mandated action but just working to educate and get people involved."
Pointer said getting rid of invasive weeds is all about timing.
"All you can do is hope they don't infest your profitable markets, and in some areas in Ketchikan it’s even too late for that," she said. "You have to fund early and attack early, otherwise it's going to be too late."
Getting rid of unwanted plants in the yard and along roadways isn’t necessarily expensive, just time-consuming, Krosse said. Orange hawkweed requires careful observation over two to three years, with repeated chemical application. It can take longer if a person doesn’t use an herbicide, she said.
Information about restricted plants in Alaska is available online at http://plants.alaska.gov/invasives/index.htm and http://www.uaf.edu/ces/cnipm/