Fall
2002 - The North Cascades
'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.
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