[Congressional Record (Bound Edition), Volume 147 (2001), Part 14]
[Extensions of Remarks]
[Pages 20259-20261]
[From the U.S. Government Publishing Office, www.gpo.gov]



      HONORING CU PROFESSOR TIM SEASTEDT FOR WEED CONTROL RESEARCH

                                 ______
                                 

                            HON. MARK UDALL

                              of colorado

                    in the house of representatives

                      Wednesday, October 17, 2001

  Mr. UDALL of Colorado. Mr. Speaker, I rise today to acknowledge the 
important work of University of Colorado Professor Tim Seastedt in weed 
control research. Professor Seastedt's exciting and path-breaking 
research on using insects and soil chemistry to control the spread of 
noxious, non-native plants holds promise in addressing a vexing--and 
spreading--problem, especially on our western lands.
  Professor Seastedt's work was recently recognized through a $280,000 
grant awarded to him by the U.S. Department of Agriculture to continue 
his work of examining the soil chemistry of diffused knapweed and 
devising a way to develop soil nutrients that kill or hamper the growth 
of this problem weed in Colorado and elsewhere. Through this grant and 
his existing work on the role of insects in controlling the spread of 
weeds, Professor Seastedt is demonstrating that we can address our weed 
problems and do so in an effective and environmentally sensitive 
manner.
  The nature and extent of the weed problem in the west is dramatic and 
serious. In Colorado alone, there are 85 species of weeds that

[[Page 20260]]

are taking root in millions of acres of rangeland, have displaced 
nearly 10 percent of the state's native plant species, have destroyed 
habitat for bighorn sheep and other wildlife, and caused upwards of 
$100 million in lost crop productivity annually. Similar impacts exist 
in many other states.
  Weeds get here and take hold for a host of different reasons. In the 
case of diffused knapweed, it is theorized that this plant came over 
from Europe from imported alfalfa crops. But no matter how they get 
here, once these plants take hold they are very hard to eradicate. In 
North Dakota, for example, where another plant--leafy spurge--is a 
particularly bad problem, the state has been spending nearly $100 
million a year to control it. Such controls involve everything from 
herbicides, mowing, hand-pulling, and the use of grazing animals such 
as sheep--all to little or no effect. The plants keep coming back. In 
addition, some of these methods, such as the spraying of chemical 
herbicides, are controversial as they may be harmful to the 
environment.
  That's where Professor Seastedt's work comes in. Given the cost, low-
effectiveness and environmental concerns of these traditional methods, 
Professor Seastedt and his researchers began looking for better 
methods. He latched on to insects. For example, in the case of diffused 
knapweed, Professor Seastedt found that a number of species of weevil 
feed upon the roots, stems, seeds and flowers of this plant. So, he 
released a swarm of them in test plots along Colorado's Front Range, an 
area especially hard hit by this weed. The result: where there once 
were 30 stems of diffused knapweed per square meter, there now are 
hardly any at all. And native grasses and plants, which are not 
palatable to the weevils, are now making a strong return.
  This story is being copied in North Dakota with the leafy spurge. 
There is a species of insect called flea beetles that seems to thrive 
on this weed with the result of reducing by half the acreage that has 
been affected there. This insect is now being used to control the leafy 
spurge problem at Colorado's Cherry Creek State Park, which has 
resulted in a 60 percent reduction of the growth of this weed at this 
popular state park.
  Insects are thus proving to be an exciting tool in our arsenal 
against weeds. The other weapon is the new research on soil chemistry. 
Professor Seastedt has been studying the soil conditions that are 
favorable to diffused knapweed. He has found that some nutrients are 
more favorable to this plant than others. Armed with this knowledge, it 
may be possible to use natural elements of the soil to enhance the 
growth of favorable plants and retard the growth of harmful ones like 
diffused knapweed. The grant from the U.S. Department of Agriculture 
will help him continue this research.
  Professor Seastedt's success in this regard will further help restore 
the health of our lands, increase agricultural productivity, and 
enhance the quality of life in the west. I look forward to the 
continuing work of Professor Seastedt and his researchers on our 
ongoing struggle to get ahead of and win our war with weeds.

                    [From Westword, Aug. 9-15, 2001]

                             Weed Whacker!


      Tim Seastedt takes no prisoners in the war against knapweed

                         (By Harrison Fletcher)

       Tim Seastedt is at war.
       His enemy is a drifter, voracious and cruel, striking fast 
     and furiously. By 1997, it had already ravaged more than 
     three million acres of rangeland in the West and fought off 
     assaults by ravenous goats, chemical agents and 
     flamethrowers.
       Then Seastedt arrived on the scene, squaring off against 
     the scourge on a 157-acre slice of prairie in Boulder County. 
     His chances didn't look good: What could one lanky ecologist 
     from the University of Colorado do to combat the dreaded 
     Centaura diffusa? Study it to death?
       But now, four years later, on a bright summer day, Seastedt 
     strides through the pasture like an actor in an allergy-
     relief commercial, wearing a T-shirt bearing the words 
     ``Ecology With Attitude.'' Looking beyond the wildflowers, 
     butterflies and meadowlarks, he spots signs of death and 
     destruction. Weeds with stems stripped bare. Weeds with 
     leaves eaten away. Weeds with seedheads decimated. Weeds 
     starved for nutrients. Weeds pushed back by native grasses. 
     Seastedt bends down on one knee and plucks a spindly forb 
     from the damp soil.
       ``This guy's not going to make it,'' he says, examining the 
     taproot, which has been split wide open by a burrowing 
     weevil. ``This is more than just good news. This is advanced 
     good news!'' Seastedt casts aside the carcass and continues 
     his stroll. Out on the prairie, armed with little more than 
     bugs and fertilizer, he is winning the war against diffuse 
     knapweed.
       Colorado officials list 85 weeds they'd just as soon see 
     wiped off the face of the earth--plants that have overrun 
     millions of acres of rangeland, displaced 10 percent of the 
     state's native plants, destroyed habitat for bighorn sheep, 
     elk and sage grouse, and caused $100 million in lost crop 
     productivity annually. Diffuse knapweed ranks in the top five 
     on this roster, behind only Canada thistle, field bindweed, 
     Russian knapweed and leafy spurge. At last count, 83,000 
     acres along the Front Range along were infested with diffuse 
     knapweed, most of them in Boulder and Douglas counties.
       Under the 1991 Undesirable Plant Management Act, every 
     county is required to develop a plan to identify and handle 
     noxious weeds. And so county officials wrote rules, formed 
     weed-management boards, coordinated strategies and set about 
     to educate the public. But they've had trouble enforcing the 
     rules, coordinating the strategies and educating the public. 
     So the act was amended in 1996 and the position of state weed 
     manager created.
       Today, however, Eric Lane, Colorado's weed manager, 
     grudgingly draws this conclusion: ``Uninfested areas are 
     still becoming infested. In that respect, with this one 
     species, we are slowly losing the battle.''
       Enter Tim Seastedt
       A 52-year-old Nebraska native with a suntanned face, 
     bristle-brush mustache and vocabulary loaded with phrases 
     like ``biomass'' and ``stem density,'' Seastedt started his 
     scientific career as a zoologist in Montana, tagging grizzly 
     bears. But he longed to ``solve big-picture questions'' about 
     ``whole-level landscapes,'' and after spending two years as a 
     Peace Corps worker in Tonga, ``waiting for Nixon to solve 
     Vietnam,'' he returned to the U.S. and became an ecologist. 
     He studied in Alaska and Georgia and Kansas, where he 
     specialized in grasslands, ``trying to understand why 
     dominant species are dominant.'' He arrived in Colorado in 
     1990 and became a professor of environmental population and 
     organic biology at the University of Colorado. In 1996, at 
     the height of the battle over herbicides in Boulder County, 
     Citizens for Alternatives to Toxins in Boulder tried to 
     enlist Seastedt's help. He turned them down, but when they 
     asked again a year later, Seastedt offered to review the 
     scientific reports for Boulder County's weed plan.
       ``But there were no reports,'' Seastedt recalls. ``There 
     was no science justifying their management program. As an 
     ecologist, I was used to doing science-based, ecosystem land 
     management. The first ground rule is you obtain data. I 
     thought, `If they're doing these things without data, there 
     might be a problem.' ''
       Although Seastedt wasn't officially affiliated with the 
     anti-toxics group, he sympathized with them. When fighting 
     weeds, employing herbicides is like using an anvil to hammer 
     a nail. ``My advocacy has always been the least toxic 
     approach,'' he says. ``In my mind, using that stuff as a 
     routine tool was just unacceptable.''
       So he started doing some investigating of his own. And he 
     realized that while the chemicals were killing a lot of 
     weeds, ``the weeds are just going to come back. We need 
     something more sustainable.''
       His first thought was bugs.
       In Colorado, insects have been used to fight diffuse 
     knapweed for more than a decade, with decidedly mixed 
     results. But when Seastedt visited places such as Walker 
     Ranch, where bugs have been deployed on and off for years, he 
     found that at least one species, a weevil, had enjoyed some 
     successes before being hindered by herbicide spraying, weed 
     pulling or mowing. So despite the popular consensus that bugs 
     had failed, Seastedt was encouraged. ``I saw evidence that 
     biocontrols could work, given enough time,'' he says.
       After getting the green light from Boulder County to 
     conduct this experiment on 157 acres near Superior, he 
     visited state agricultural offices and loaded upon on free 
     bugs. But instead of releasing one or two species, which had 
     been the approach in the past, Seastedt decided to use five 
     bugs to attack different parts of the weed simultaneously. If 
     one bug died or moved along, another would take over.
       So in the summer of 1997, Seastedt released fifty root-
     boring weevils named Cyphocleonus, which feed upon infant 
     knapweeds and lay eggs on their roots. Then he released 300 
     beetles named Sphenoptera jugoslavica, which attack the 
     roots, stunt growth, reduce flower production and kill 
     rosettes. Next, he released 200 Larinus minutus seedhead 
     weevils, which lay eggs on flowers, eat blossoms and gobble 
     up seeds. Two species, seedhead gall flies called Urophora 
     affinus and U. quadrifasciata, had already been released; 
     they lay eggs on flowers and sap the weed's energy.
       Then he waited.
       For two years, nothing seemed to happen. In fact, he 
     remembers, the weeds got bigger and covered more ground. But 
     in the summer of 1999, Seastedt noticed a bug boom, an 
     exponential growth of insects ``straight out of an ecology 
     textbook.'' Then weeds became stunted. Then weeds stopped 
     producing as many seeds. Then they stopped spreading as 
     rapidly.
       When he studied the results this summer, even Seastedt was 
     surprised: Rosettes have

[[Page 20261]]

     dropped from 50 per square meter in 1997 to three; seed 
     production has been slashed from 5,000 per square meter to 
     blow 100; adult weeds have fallen from twenty per square 
     meter to less than five. And weeds that appear healthy are 
     little more than insect reservoirs, serving as both a home 
     and a food source. By next summer, he says, those weeds will 
     be producing new bugs instead of new knapweeds. And if that 
     happens, the insect population could soar beyond twenty 
     million--enough to supply knapweek-eating bugs to the entire 
     Front Range.
       ``Look at this,'' Seastedt says, yanking a droopy weed from 
     the pasture. ``What we're getting are these wimpy little 
     plants. Roots have been hit. Seedheads are empty. They've 
     been defoliated. Larinum has done its damage. The gull flies 
     have been doing their thing. There's just nothing here to 
     support the final product. Next year, I'm not sure there will 
     be knapweeds here.'' With the knapweed in full retreat, 
     native plants will be free to take their place. Some already 
     have.
       ``When we started, you could hardly find June grass here,'' 
     Seastedt says. ``And when you did, it was just these tiny 
     clumps. Now it's all over. The recovery has just been 
     spectacular. Next year, I predict 90 percent restored 
     prairie. And the 10 percent of knapweed that is here will be 
     grazed to the ground.''
       Even if the bugs are successful, Seastedt believes that the 
     ultimate way to beat diffuse knapweed is to understand why is 
     has flourished in Colorado--and then reverse the process. His 
     team is trying to do just that on the land outside Superior. 
     Here is Seastedt's theory. Diffuse knapweed has been able to 
     thrive in Colorado because, among other things, changes in 
     the soil over the past 150 years gave the weed a competitive 
     edge. First, the rangeland has been grazed continuously, and 
     plants that might have offered competition have been 
     repeatedly nibbled away. Second, fires have been limited, and 
     fires cleanse the soil of nutrients that weeds love, 
     including nitrogen. In fact, scientists have discovered that 
     one of the fastest ways to turn healthy grasslands into weed 
     fields is to add nitrogen. And nitrogen, as it turns out, is 
     the third factor: Nitrogen levels have been rising steadily 
     in the soil, in part because of increases in atmospheric 
     deposits.
       Seastedt wonders: Can scientists reverse the process? Can 
     they tinker with soil chemistry and restore rangeland to its 
     pre-knapweed condition? And if they succeed, will it blunt 
     the weed's competitive edge? Will it bring back healthy 
     native plants and grasses?
       To find out, Seastedt and researchers Katie Suding and Kate 
     LeJeune cordoned off certain plots and added nitrogen. The 
     plants--particularly pepper grass, which grew in thick 
     bunches loved it. But diffuse knapweed stayed more or less 
     unchanged.
       Interesting, the researchers thought. Perhaps nitrogen 
     wasn't so vital to knapweed after all. Perhaps another 
     nutrient determined whether the weed would live or die. In 
     other parts of the world, like the tropics, phosphorus is a 
     key nutrient; perhaps knapweed needed phosphorus. So they 
     added phosphorus, and while other plants stayed more or less 
     unchanged, diffuse knapweed bulked up like a linebacker on 
     steroids.
       Interesting, the researchers thought. Diffuse knapweed 
     liked phosphorus; perhaps phosphorus would prove knapweed's 
     Achilles heel.
       So they tinkered some more, adding phosphorus and nitrogen, 
     removing phosphorus and nitrogen, pulling knapweed from some 
     plots and leaving knapweed in others. Although it's too early 
     to tell what the results of this summer's experiments will 
     be, they think they're on the right track. In May, they were 
     awarded a $280,000 federal grant. Now if they can find the 
     right mix of phosphorus, nitrogen or some other nutrient, 
     they might be able to tip the balance away from knapweed and 
     toward native plants and grasses.
       ``Once native grasses are happy and healthy again, we think 
     they are capable of greatly reducing knapweed,'' Seastedt 
     says.
       No matter how successful his experiments, Seastedt doesn't 
     believe diffuse knapweed will ever be completely eradicated. 
     In fact, he doesn't think weed managers should even try. At 
     best, they can only hope to reduce the weed to a level that 
     allows native plants and grasses to return. ``What I'd like 
     to see is a prairie dominated by the vegetation we want to be 
     there: native plants given the maximum potential to express 
     diversity,'' Seastedt says. ``If that means 1 or 2 percent 
     cover by diffuse knapweed, that wouldn't bother me at all. It 
     would be just like the dandelion. And if we can get knapweed 
     to be like a dandelion, then we've done our job.''

     

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