Can we Win?

Idaho's invasive species wars

by Mary Ann Reese

Illustration by Noah Kroese

You're boating on Lakes Pend Oreille or Coeur d'Alene when your propeller suddenly stops, snarled in webs of Eurasian watermilfoil. Or you're hiking a favorite trail in Hells Canyon, only to find waist-high needle-sharp yellow starthistle thwarting your way.

Idaho anglers may be inadvertently spreading tiny New Zealand mudsnails from Idaho's Snake River to prized trout waters such as Silver Creek near Sun Valley. People moving here may be accidentally bringing gypsy moths with them.

Idaho food producers each year face crop losses when non-natives such as the potato tuber worms or cereal leaf beetles show up. 

Welcome to the world of Idaho's invasive species--alien organisms that affect how our native and agricultural systems function and that cause ecological and economic harm.

Illustration by Noah Kroese.

Some 50,000 non-native plant and animal species now live in the United States. Many are beneficial or no problem. But some 7,000 are considered troublesome. Idaho agriculture, working with the USDA's Animal and Plant Health Inspection Service (APHIS), routinely watches for some 400 exotic plants, insects, or organisms considered potential threats to Idaho agriculture alone.

“No environment is safe from invasive species,” says Pat Takasugi, director of the Idaho State Department of Agriculture (ISDA).

“Risks are increasing as people travel more, trade from other countries increases, and more people move here. It's not only agriculture and our environment, but women, men, children face potential risks from things like avian bird flu and West Nile virus.”

Concerns for the future

“I'm concerned about the future,” admits Ben Simko, ISDA program manager. “The battle is getting tougher. Risks and pathways moving into the Gem State are increasing all the time, but funding isn't keeping up.”

Increasing numbers of scientists consider invasive species a big threat to native habitats and endangered species. They may be “our most serious threat, more serious than global warming or ozone depletion,” states the 104-page 2005 Idaho's Action Plan For Invasive Species.

Idaho already loses some $300 million annually to its weed problem alone. “We have lost vast acreages of grazing land to noxious weeds like diffuse knapweed or Dalmation toadflax. We're in the process of losing wetlands to purple loosestrife,” adds Takasugi.

In March the Idaho Legislature took reports of Eurasian watermilfoil besetting Idaho's pristine lakes and rivers seriously enough to set aside $4 million to battle it early. And it funded a statewide invasive species coordinator position, reporting to Takasugi. Phil Bandy, interim coordinator, is already bringing together concerned federal, state, and county agencies.

Roles for UI CALS and CNR

UI College of Agricultural and Life Sciences (CALS) leaders asked our editors to do this story because so many college faculty, researchers, students, and UI Extension educators and scientists are committed to wars against invasives, as are faculty and students at our sister College of Natural Resources (CNR--see CRISSP).

UI Extension plant pathologist Krishna Mohan coordinated Idaho's part in a National Plant Diagnostic Network to help speed identification of high-risk problems. Many UI Extension educators play active roles in Idaho's innovative Cooperative Weed Management Areas (CWMAs), writing action plans, researching solutions, or training teams to identify weeds.

In a recent survey, every UI Extension educator and scientist who responded agreed they were “very concerned” about existing and looming problems.

Our college's Lambert Erickson Diagnostic Weed Laboratory has helped Idaho agencies and residents identify plants since the 1980s. “We've had 300 a year. Then 400 a year. Last year we identified 600. Most are weeds,” says Tim Prather, UI Extension weed specialist, lab director, and one of the UI's key invasive weed warriors. Prather helped write an invasive weed action plan, on which Idaho's action plan is modeled.

UI CALS faculty, students join with agencies in noxious weeds battles

Noxious weeds form one of Idaho's most visible and entrenched sets of invaders.

The 36 weeds on the state's official noxious list “choke Idaho's streams and waterways, crowd out beneficial native plants, create fire hazards in our forests and rangelands, poison and injure livestock and humans, and foul recreation sites,” according to Idaho's Noxious Weeds, a $5 pocket-sized guide to identifying and dealing with each weed. It's one of the UI Extension's best-selling publications, written by six UI CALS weed specialists (order it at www.cals.uidaho.edu/edComm/catalog/).

Nobody knows total acreage of Idaho's infestations, but it's huge, impacting most counties, cities, and towns. One Bureau of Land Management survey in 2002 confirmed almost 200,000 acres of its Idaho lands as weed infested, but guessed 421,000 acres was probably “more accurate.” Weeds like yellow starthistle (Centaurea solstitialis), which can cause death in horses, expands by 3 to 4 percent a year. You do the math.

Idaho's CWMAs start a national trend

“How do you define an infestation? That's the question,” says Jim Hawkins, Custer County's UI Extension educator who has doubled as county weed superintendent for 33 years. “One plant has potential to affect millions of acres. Or is it just the square foot it is sitting on? We beat invasives back, but then they surface somewhere else,” says Hawkins, outlining a frustration felt statewide and even nationwide.

Idaho counties have fought weeds for years. Idaho law holds private landowners accountable for weeds on their turf. Failure to remove them can result in fines.

After Pat Takasugi took over as ISDA director in 1996, he and the late Glen Secrist, then head of ISDA's Bureau of Vegetation Management, created the nation's first Cooperative Weed Management Areas, designed to fight weeds in whole ecosystems. 

Lynn Danly, left, of the U.S. Bureau of Land
Management at Cottonwood and UI's
Sandra Robins confer over their
handheld computers documenting
new Idaho County weed investations.

This model has worked so well that Idaho Sen. Larry Craig took the program to the nation and lobbied six years to pass 2004 legislation making it possible for all states to set up CWMAs and apply for funding.

“Sen. Craig's focus is how do we tackle a $100 billion problem, with economic damage so large and resources so limited,” says Travis Jones, Craig spokesman in Washington D.C. “The great thing about CWMAs is they promote collaboration among all agencies and groups with a problem, and they put the funding on the ground, with people who know the problems best.”

Idaho's model is being adopted throughout the West and elsewhere.

Battle strategies include bugs, goats, sprays, school kids, satellite imaging, helicopters, etc.

As with military wars, Idaho's weed wars use all available tools, and the search for better tools is unending. Reading through paragraph-long 2005 CWMA summaries on the ISDA website, you'll find every strategy in the sub-head above, and more.

Most CWMAs stage weed days or weekends, when state, federal, and private landowners combine efforts in targeted infestations. 4-H club members and school clubs and science classes join the fray, learning to identify and battle noxious weeds. Goats and sheep can trim some weed acreages by eating them at specific times. 

CALS and UI Extension faculty, researchers, and educators pitch in to document what works best, and share best practices with on-the-ground warriors.

Here are other strategies currently in use.

Early detection and rapid response

A task force of the Idaho Weed Coordinating Committee is developing an early detection and rapid response system for Idaho, designing a system to find weeds early in the invasion process and remove them before their populations explode to cause economic and ecological harm. 

UI's Prather, on the task force, also works with Leonard Lake, USDA Forest Service, and Carl Crabtree, Idaho County, to determine kinds of sites most susceptible to invasion.  Once they identify characteristics of highly susceptible sites, they will design a detection survey schedule to find invasive plants when they first enter Idaho.

For example, the group finds frequently used air strips in wilderness have greater numbers of weed species than infrequently used air strips. They also find high elevation locations in areas that support more plant variety are less likely to contain weeds. Most higher elevation air strips did not have weeds, with only one site supporting 15 percent exotic species, contrasted with low elevation sites in grasslands where all air strips had exotic species, often greater than 70 percent of the plant population.

Strategic mapping/predicting

By far the cheapest way to battle invasive species is to find them early and eradicate them immediately. One way is to study how weeds spread, predict where they'll go, and prevent their spread.

Yellow starthistle (YST) is thick in central Idaho and may be impossible to eradicate, but may be prevented from spreading north or south.

UI faculty members Prather and Bahman Shafii and statisticians Larry Lass and Bill Price have used maps detailing locations of yellow starthistle in 1981 and 1987 to predict where YST would invade. Maps of potentially susceptible areas now focus The Nature Conservancy efforts to prevent starthistle's continued southern expansion in Hells Canyon.

Salmon junior high students learn
to identify noxious weeds and greet
goats that conquer them at Nancy
Cummings center (top photos).
Photos by Joel McNee.
Mark Porter, in helicopter,
maps location of weeds for teams on ground.

Knowing where the plant will go allows land managers to design strategies to prevent its continued movement.

Nature Conservancy's aerial mapping and SWAT teams purge Hells Canyon

The Nature Conservancy's Idaho chapter, which operates the 1,400-acre Garden Creek Ranch where the Salmon meets the Snake River, partnering with the Tri-State CWMA, has ramped up weed battles for four years.

Hells Canyon teams devote summers to noxious weed eradication. “We see yellow starthistle taking over whole hillsides that used to be very diverse wildflower and bunchgrass communities,” says Bas Hargrove,  senior policy representative and UI alum.

Back in Hells Canyon, two-person teams spend their summer hiking to remote fresh YST invasions in Hells Canyon, based on UI maps predicting where new infestations will appear. 

But first, environmental scientists hover 40 feet above the ground in helicopters over areas where weeds are predicted. “The job requires a strong stomach,” laughs Mike Atchison, a UI master's graduate in environmental science and project lead for The Nature Conservancy. Once he spots weeds, the patch is mapped using Global Positioning Systems and Geographic Information Systems. They call it digital aerial sketch mapping, “a fairly inexpensive way to survey big rugged country where ground surveys are impossible,” adds Atchison.

Those coordinates go to an on-foot SWAT team--Strategic Weed Action Team--often two UI students, who hike in to eliminate the weeds. “We concentrate on areas that are 95 percent weed free. We want to keep them that way,” says Atchison.

Bring in the “good” bugs

Insects are gaining in popularity as allies in weed wars, part of integrated pest management (IPM) strategies that seek combinations of least invasive, most economical, most effective practices.

The USDA's Cooperative State Research, Education, and Extension Service (CSREES)--with oversight of all land-grant colleges--calls the bugs part of “biobased management,” or suppressing pests by using natural enemies--predators, parasites, competitors, and diseases.

Insect emerges from a bug bomb.
Above, field of the noxious leafy
spurge was suppressed by
A. nigriscutis, a root beetle.
Photos by Chad Cheyney.

When you live in a county like Custer--Idaho's third largest, home to 13 of Idaho's tallest peaks including Mt. Borah--and you only have 4,000 citizens, then bugs start looking especially useful.

Jim Hawkins finds knapweed root weevil (Cyphocleonus achates)  works well on spotted knapweed. “Once established they are very effective,” says Hawkins. Their larvae eat the roots, killing plants.

“They don't eat themselves out of house and home. But they can knock a stand of spotted knapweed down from several hundred acres to a sprayable acre or two,” says Hawkins. As knapweed subsides, natives like Idaho fescue or bluebunch wheatgrass grow back or are planted.

Over a decade “bug bombs” dropped from airplanes over otherwise inaccessible landscapes, or hiked in by teams on the ground, have established maybe 200 insectaries in the county.

“Spraying only lasts a year, then the weeds are back,” says Challis High School's Amanda Robinson, part of an environmental club that helps collect and distribute weed-fighting bugs for Hawkins. “Bugs are best,” adds fellow-student Katie Fox. “They stay as long as the weeds do.”

“You have to be a good fisherman … patient,” adds Hawkins. “It's not like spraying, where you go the next day and weeds are all laying over. It takes time before bugs have enough numbers to make an impact.”  If you want to get in shape, he adds, “spend the summer working for us.”

What's next?

When the Idaho Academy of Science met for its 48th symposium on the UI campus in March, keynote speaker Richard Mack from Washington State University's School of Biological Sciences spoke on “Addressing the Threat of Invasive Alien Plants: A Blueprint for National Action” The blueprint. See other online resources.

“Threats are greater today,” said Mack, “but so is our awareness. So are our tools for fighting them.

“I am hopeful.”

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