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
 

This guy is lovely!" ecologist Beth Leger exclaims, falling to her knees. A tiny, energetic woman in her mid-30s, Leger hovers, bee-like, over a teensy grass with blue-green blades. It is, she tells me, a "cute" native called Poa secunda.

It's early May, and Leger, graduate student Owen Baughman and I are crouched on Peavine Mountain, a scrubby rise near the University of Nevada, Reno, where she is an associate professor of plant ecology. The ground around us is covered with the invasive annual Bromus tectorum, also known as cheatgrass. This is not surprising; the Great Basin is a disturbed landscape, and cheatgrass is now its dominant inhabitant. Around the little Poa though, there is no cheatgrass at all, just a foot of bare, pebbly dirt. "We did some trials to see what native perennials were the most competitive with cheatgrass, and it was this guy," says Leger.

Leger scoops away the soil around its base, digging carefully underneath it. "I don't want to kill him, but it's instructive to do that because his roots are super fine and they go out really shallowly, all through this area," she explains, gesturing at the bare circle. "Cheatgrass (also) has super-fine roots and this is about the only native plant I've ever seen that has the same sort of roots." That allows the Poa to take up space and use nutrients the weedy invader would typically claim. Determined to show me its root structure, Leger finally pulls the demonstration plant out of the ground, sacrificing it for the sake of knowledge. "Sorry, dude," she tells the grass. "You'll be famous."

The ancestors of Leger's beloved Poa first encountered cheatgrass, a native to parts of Europe and Asia, in the late 1800s. Western settlement had brought widespread livestock grazing to the Great Basin, a Texas-sized area that covers 180 million acres in southeastern Oregon, southern Idaho, western Utah and Nevada. That was a shock to native bunchgrasses like Poa and Indian ricegrass, which, in that part of the West, had evolved in an environment unused even to bison. Cheatgrass seized its opportunity. The weed hitchhiked from Europe in contaminated seed, straw and ship ballast, and crisscrossed the West with the railroads, which spread it with the straw used for livestock. By 1930, cheat was everywhere. As Aldo Leopold wrote in the 1949 classic A Sand County Almanac, "One simply woke up one fine spring to find the range dominated by a new weed."

That new weed would drastically change the region's fire ecology, among other things. In a typical Great Basin shrubland, forbs and grasses grow patchily underneath a canopy of well-spaced shrubs like sagebrush and shadscale. In contrast, cheatgrass masses in a smothering mane. Its survival strategy is to beat out other plants, Red Army-like, through its sheer numbers: It can drop 50,000 seeds per square meter. An annual, it dies off every year, leaving a thick thatch of flammable material. Even the smallest spark can set off fast-moving fires that kill off any remaining native shrubs. Then, next growing season, those millions of cheatgrass seeds outcompete any surviving natives. After the first burn or two, the fire cycle is forever changed. Normal fire frequency in the Great Basin is every 30-70 years; cheatgrass monocultures burn every three to 10. The bare soil left after fire can blow away in spring and land on snow in far-away mountains, causing quicker melt-off. With nowhere to hide and no shrubs to browse or nest in, wildlife -- including mule deer and the imperiled sage grouse -- quickly move out.

For many years, the Bureau of Land Management, which manages much of the land in the Great Basin, more or less ignored cheatgrass. In the mid-1980s, though, a number of large fires swept through sagebrush communities, and land managers began investigating how to protect and restore the habitat. Then, in the summer of 1999, the Great Basin burned as never before, with fires marching across almost 2 million acres. That forced the agency to take a more aggressive approach to fighting cheatgrass. Yet so far, many restoration efforts have come up short, as native soil erodes after fires, planted seeds fail to establish, and cheatgrass returns en masse. Today, ecologists estimate that it has expanded to between 20 to 50 million acres in the region, and forms a near monoculture in at least 10 to 12 million of those acres.

Cheat isn't even the worst thing that could happen to the Great Basin. Now that the ecosystem is essentially shattered, new invaders have an easier time moving in. Plants like medusahead wildrye, thistles and knapweed lurk in the wings. Unless cheat-altered landscapes can be made more resilient, one of these may become the next great invader, says Mike Pellant, a rangeland ecologist who coordinates the BLM's Great Basin Restoration Initiative. And, Pellant warns,  "we don't know which one and where and how fast. So if you think of a downward spiral, cheatgrass is not the bottom of the ecological barrel in the Great Basin."

That's the dark side, he says. "The bright side is we've got great scientists working on the problem." Of course, even the best science can't give the BLM the ability to treat 50 million acres of invaded land, especially when funding for reseeding comes primarily in a reactive rather than proactive form, tied to post-fire restoration. Pellant says any efforts to fight cheat will be mostly focused in sensitive places like wilderness study areas and important sage grouse habitat. A silver lining to the bird's decline is the federal money dedicated to keeping it off the endangered species list, which enables the agency to do more restoration.

Those priority areas can use any help that Leger, and her cheatgrass-fighting native plants, can give. And she's not alone; the effusive scientist is working alongside an Avengers-like posse of restoration scientists, all raring to put into practice new knowledge about the best way to fight Great Basin cheatgrass.

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.