Great Basin scientists unleash new weapons to fight invasive cheatgrass

  • Beth Leger looks for native plants amid a field of invasive cheatgrass near Winnemucca, Nevada.

    Stephanie Paige Ogburn
  • Beth Leger and Owen Baughman study a test plot of cheatgrass on Peavine Mountain outside Reno, Nevada.

    Stephanie Paige Ogburn
  • A mature Poa secunda in early October, with leaves greening up in response to fall rains.

    Beth Leger
  • Petri dishes in Susan Meyer's Provo, Utah, lab hold the fungus called Black Fingers of Death, which works against cheatgrass.

    Stephanie Paige Ogburn
  • A T-shirt celebrating the fungus called Black Fingers of Death, which works against cheatgrass.

    Stephanie Paige Ogburn
  • A scanned image of the roots of the invasive annual grass Bromus tectorum. Extensive fine-root production is probably key to this plant's success in capturing water and nutrients in arid ground.

    Beth Leger
  • The native annual forb Amsinckia tessellata with its broad leaves does a great job suppressing Bromus tectorum (linear leaves, barely visible) in an outdoor experiment.

    Beth Leger
  • A fire line in the 2006 Basco Fire in Elko County, Nevada, protected the mature sagebrush community on the right side of the mountain.

    Beth Leger
 

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"Ugh, it's so depressing." Beth Leger is tromping through a golden-thatched valley in northwestern Nevada near the town of Winnemucca. It's full of dried cheatgrass. As a chill wind whips our clothes, our eyes comb the ground, searching for plants other than cheat. "It's remarkable to me that there can be this little diversity," sighs Leger. She's surprised, too, because although it's common to think of fields of cheatgrass as devoid of any other species, her research has found otherwise.

When Leger first came to Reno, like most restoration scientists, she viewed cheatgrass-invaded landscapes as monocultures, where native plants no longer existed. Yet one day, exploring nearby Peavine Mountain, Leger noticed a sprinkling of native grasses among the weeds. She wondered if they'd be useful for restoration, since they must have adapted somehow in order to fight off the weed and survive. So she waded out into a cheatgrass sea, dug up a few native plants, and started conducting experiments.

Leger collected natives from cheat-covered areas and natives from more intact ecosystems, planted them alongside cheatgrass, and measured how they grew. "It's kind of like boxing. You put them in a ring and see who wins." Her early results were impressive. A number of plants from the weedy areas suppressed the growth of cheatgrass and were also able to successfully reproduce.

"A native plant! I found one native plant!" shouts Leger. Kneeling, the ecologist grins for the first time since our arrival in the cheatgrass sea. "It's a Lomatium. In terms of its restoration potential I don't think it's really one of the big players for competing with cheatgrass, but in terms of diversity it's good."

Back at her University of Nevada test plots, Leger has experimented to pinpoint the most competitive natives. She takes me to a dry field surrounded by fencing, where a few green plants have a foothold. "This is squirreltail," she says, pointing out plants that have proven to outcompete cheatgrass. "Amsinckia is one, Mentzelia, this is a lovely one, pretty big after fires."

Leger calls the Amsinckia a "weedy native," because it likes disturbed sites. Her test plots have largely failed this year due to lack of rain, but a few plucky Amsinckias persisted. Last year, when Leger experimentally planted Amsinckia near cheatgrass, the native reduced the weed's size by 97 percent and suppressed its seed production from 576 seeds per plant to just 76.

In a natural succession scenario, Amsinckia and other weedy natives would be some of the first plants to colonize a burned or disturbed area. But plants like Amsinckia have seldom been included in restoration seed mixes, partly because they are toxic to cattle, and partly because managers have wanted to seed plants like sagebrush that would be found in a mature Great Basin plant community. If Amsinckia were used in restoration, though, Leger believes it could truly act like a colonizer. It would fight off cheatgrass, but only stick around for a couple years. That would give some time for other perennial natives like squirreltail or Poa to establish, after which they can also do their part fending off cheatgrass.

Leger sees her and James' work as complementary to what Meyer is doing with Black Fingers of Death. "If you could knock this whole (cheatgrass) seed bank down by 90 percent (with BFOD) and could put some plants in there that could just survive for that first year, the next year might be awesome."

As Leger and I crunch through the patch of dead cheatgrass outside Winnemucca, the ever-present wind stiffens and the sky grays. The effusive scientist's optimism falters slightly, as she ponders the magnitude of the problem. "The scale of this is ridiculous. This is just one little spot. Think about how many native seeds would need to be planted here. It's unbelievable. And we don't even have a recipe (for restoration). So our hope is that we can find a recipe."

That recipe might go something like this: October comes, and a specially modified drill seeder trundles across the thatch, planting fungicide-coated Poas, Amsinckias, and squirreltails -- the tough ones Leger bred from her collections -- at depths where they are more likely to succeed in the upcoming dry winter. Soon after, a plane flies over, dropping herbicide for the early cheat seeds and granules of death-dealing Black Fingers for the later ones. In a few years, small sagebrush are sprouting, Indian ricegrass reappears, and latecomer perennials like larkspur and penstemon start to make a comeback. The next fire to sweep through doesn't come for 20 more years, and by that time, enough native seeds have dropped in the soil that plants regenerate on their own, or with only a little human help. Leger, I think, imagines this too, but her hope is somewhat tempered.

"You look at this place and you can see very realistically: We could still fail. But I think we at least need to try some of those more carefully designed ways. And then if we still fail, I think we need to stop. But I'm not ready to stop trying."

This story was funded by a Fund for Environmental Journalism Grant from the Society of Environmental Journalists.

Katherine A Ball
Katherine A Ball Subscriber
Sep 18, 2012 02:35 PM
The devil..... one of the benefactors of cheatgrass in the Great Basin is another 'fernr', the chukar partridge. If the cheatgrass goes away, will the chukar , too? It's handsome confounding quarry that resides in the most god-forsaken-human breaking rugged terrain in that wilderness of publicly-owned, easy access lands... I curse the cheatgrass in my dogs fur, tear ducts, even sub-cutaneous intrusions... not to mention my clothes etc, the devil...
Erica Husse-Jerome
Erica Husse-Jerome Subscriber
Sep 18, 2012 07:54 PM
Many- actually, the majority- of BLM fire rehabilitation programs in the Great Basin are already using Poa secunda and Elymus elymoides (squirreltail) in their seed mixes. The other forbs mentioned in the article (Lomatium, Amsinckia, Mentzelia) would certainly be used and have actually been requested, but they are not available for purchase (remember, that one forb seeded at a reasonable rate of 1 lb per acre over a relatively small 5,000 acre fire is 5,000lbs of that seed. When the Great Basin burns several hundred thousand acres per year, where will that seed come from?). I also think it is important to note that herbicide application is being increasingly restricted, despite how effective it is at battling cheatgrass.

Finally, and most importantly, "success" or "failure" in post-fire rehabilitation efforts is almost always measured in the first 3 years after a fire. Could it be that we need to give these dry areas of the Great Basin and Mojave need more than 3 years to determine if a treatment is a success or a failure?
Stephanie Paige Ogburn
Stephanie Paige Ogburn Subscriber
Sep 18, 2012 09:16 PM
Hi Erica, thanks for commenting. I take your point about rehab programs already using natives, but I do not believe Beth Leger is saying Poa and squirreltail are not used, but that the cultivars that are often used are not ones that evolved to fight off cheatgrass -- remember, she tested the same plants from different areas, cheatgrass infested and not, and found that ones from fields of cheatgrass were able to fend off the weed. I'm not sure if you've read the sidebar to the article (it's listed below the main photos on this article, called "Native plant growers face many challenges,") but if you do, you'll see I address some of the problems facing the BLM in purchasing native seed and the problems in producing it, and also a chart showing the ratio of natives to non-natives used -- as Paul Krabacher says, it's just impossible to get enough native seed and it's too pricey a lot of the time. It is my understanding however that some natives like Amsinckia are not desirable for reseeding because they are not good for cattle, though, so I don't know if they would be used all the time if available or not. Thanks again for your close read. - Stephanie Paige Ogburn, online editor.
Howard Johnson
Howard Johnson Subscriber
Sep 24, 2012 11:36 AM
Stephanie, Good article, but I did not understand the term, "Red Army-like"? Could you explain that phrase, please?.. Thanks..
Stephanie Paige Ogburn
Stephanie Paige Ogburn Subscriber
Sep 24, 2012 11:52 AM
Thanks, Howard. The reference is historical, to the Russian Red Army and the large number of soldiers in that Army that they used to their advantage in both the Russian Civil War and WWII.
Howard Johnson
Howard Johnson Subscriber
Sep 24, 2012 01:33 PM
Stephanie, Thanks. A better analogy might be USA Army-like, in relation to the number of unwanted military bases installed in foreign countries. The Red Army did not invade a large number of foreign lands but simply tried to defend itself from such, ie Germany.