'Competitive Advantage'
by Heatherjune Olah
Car wheels crunch rocks on a gravel road as hikers drive to Ross Lake for a weekend excursion. What the hikers didn't plan to bring - what they weren't even aware they brought - could ruin their future vacations.
The seeds embedded in the dust of the hubcaps run off with rain. The water washes them down to the lake where they rapidly mature and spread. The plants push out native grasses and clog the banks of the lake, making them hard for animals and humans to access and uninhabitable for native species.
About 2,330 species of vascular plants are native to Washington and hundreds are specific to the North Cascades - including 13 conifer species, six fern species and at least 27 types of berries. Until recently, they co-existed with few threats from the outside world.
Currently, scientists have cataloged 236 non-native plants living in the North Cascades, said Mignonne Bivin, a member of the North Cascades National Park exotic species management team.
For thousands of years, the American Indian trade of goods along the Pacific coast brought plants from one area to another, said Pat Milliren, also a member of the team.
In the mid to late 1800s, however, westward expansion from European settlers brought dramatic and rapid change to the Northwest, said Laurel Baldwin, Noxious Weed Control Board county coordinator. Settlers and immigrants from Asia and Europe flooded the region, introducing new species to the rich, rocky soil of the North Cascades.
The problem with introduced species is not only their capacity to out-compete native plants but their cumulative effects on entire ecosystems - plants, animals, land and the people who use the land, Huxley College professor John Rybczyk said.
"When a species invades, it has a competitive advantage over the species that lives there," he said. "When a new species comes in, it doesn't have any natural predators, it has nothing to compete with it. It has no natural pathogens, no diseases, so it can just grow and be extremely productive unlike the native species that are there."
In addition to pushing native species out, non-native plants are fire hazards and frequently toxic to humans and animals. They also interfere with wetland restoration and clog natural recreational areas with overgrowth.
Invasive species are the second-leading cause of biodiversity loss in the United States behind habitat fragmentation - urban developments that cut into and across natural areas -said Catherine Hovanic, administrator of the Washington Native Plant Society.
Nationwide, the United States loses 4,600 acres every day to introduced species, Baldwin said.
"There are other plants dependent on these (native) populations, and they are also being negatively affected," Hovanic said. "They tend to dominate an area, displacing native plant species."
She said ecosystems are very complex. As non-native plants push out native species, they displace the organisms dependent on native plants.
"(Non-native plants) create a monoculture, which is an environment that has one plant in it, instead of several species, which wildlife need," Baldwin said.
Contemporary contamination can come from people wanting exotic species in their gardens, but non-native species also arrive in ship ballasts, soil, car wheels or even animals, Baldwin said.
"(Gardeners) just get tired of what we have and want something different," she said. "Most people aren't aware (their plant is an invasive species). Other people are aware and just don't care."
A number of non-native plants are such a common sight that it almost appears they have always been here. Some of the most common non-native plants to the North Cascades include foxglove, tansey ragwort, St. John's wort and holly.
A recent problem is reed canary grass, which thrives in wetlands. It dominates Ross Lake, a reservoir above Diablo Dam, as well as many other low-elevation lakes in the North Cascades, by clogging the lake's banks and pushing native plants out, Bivin said.
But reed canary grass, considered an aquatic weed, is also starting to appear along roadsides and trails in the mountains, Milliren said.
"It sort of confounds me because it's not what I necessarily consider a wet (enough area)," she said. "On Ross Lake we have not done anything about it. I don't think we can do anything. If we had lots of money we could probably try and dig it up, but it's in some very large patches now, so it would be a very hard thing to do."
One method of removing reed canary grass near trails is planting cedar trees by the patches of grass. Reed canary grass won't grow in shaded areas and the trees soak up much of the water the grass needs to thrive, Milliren said.
Hovanic said non-native species grow in every region of Washington.
"Even within the interior forests, along the trail sides, you can find many non-native species," she said. "And that's something the Forest Service wants to stop."
Bivin said she doesn't know how to fix the system and without more money for plant work in the park, non-native plants might become a more widespread problem.
"Sometimes I feel overwhelmed, but I also know that it's possible, so I don't feel discouraged," she said. "It's just a matter of figuring out how you're going to do it. Once you get the population down to a small group, you still have to keep on and never stop pulling weeds."
Senior Heatherjune Olah studies journalism at Western. She has previously been published in The Western Front and The Valley Reporter.
