September 2011 USDA Forest Service GSDUpdate Rocky Mountain Research Station Grassland, Shrubland and Desert Science Program

What Are ? ...And Do We Really Need to Worry About Them? An invasive species is any species – non-native or native to a region – that could cause economic or ecological harm to an area. Invasives can be weeds, shrubs and trees, insects, mollusks, vertebrates and even microorganisms and pathogens such as exotic bacteria, fungi and viruses. Invasive plant species have already infested more than 125 million acres of land in the U.S., according to the National Invasive Species Council, and are moving into another three million acres every year. The cheatgrass weed alone has invaded more than 100 million acres and continues to spread rapidly.

Are invasive species really that big of a problem? people. Invasives can also affect the recreational IN THIS ISSUE Yes. Invasive species can be found almost value of public land, decrease the economic anywhere (rivers, , grasslands, forests) capacity of land to support livestock and crops, and they can have wide-ranging effects on the impact wildlife habitats and biological diversity, environment and on humans. For example, and much more. By one estimate, the damage invasives can change water flows, deplete caused by just six invasive species is about $74 nutrients and increase the risk of wildfires. billion a year. Invasives can force out other species by competing for food and space, or by introducing What Are Invasive Species? pathogens that kill or harm other species. ... And Do We Really Need to According to the National Invasive Species Worry About Them? Council, 42 percent of the species on the endangered species list are at risk primarily A New Form of Biocontrol: because of invasive species. Invasive species Fungal Pathogens can introduce new types of pollen or pathogens Classical Biocontrol with Insects: that cause respiratory ailments and other New Questions Emerging human health problems. The West Nile virus, an invasive species, has killed more than 1,000 Other Projects: Fire, Birds, Seeds and More Right: Buffelgrass (Pennisetum ciliare) now infests parks created to protect Sonoran Desert ecosystems. It forms What Can You Do About a blanket of cover that can carry fire and threatens iconic Invasive Species? native species such as saguaro cactus (Cereus giganea). Bozeman Biocontrol Lab Renovation Photo: Saguaro National Park, Arizona – Almost Done! Left: Saguaro provides nest cavities for the cactus ferruginous pygmy owl (Claucidium brasilianum cactorum) Meet Some of the GSD Scientists Photo: Norm Smith Recent GSD Publications

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Preventing, detecting, and managing invasive studies explore how damage can be minimized, species are no easy tasks. Scientists do not assess the risks and benefits of various control fully understand all of the processes by which strategies, and help to develop models that can species move into an area, or what makes an predict the severity of future outbreaks. Control area at risk of invasion. They also need to better and management studies look at the details understand how control measures that work in of various control methods, such as classical one area might be used elsewhere, as well as biological controls, and how they might work the best ways to restore and rehabilitate an area. better and the risks they can pose when used in As with most any , understanding a new area. Studies in this area are also looking Rush skeletonweed (Chondrilla juncea at non-classical biological controls such as L.) invades dry in the complex relationships and how one species can western United States, displaces affect others is a complex puzzle that requires fungal agents (see A New Form of Biocontrol: native species, and reduces forage time to work out. Fungal Pathogens on page 3). Finally, restoration for livestock and wildlife. and rehabilitation studies are looking at the Photo: Steve Dewey, The USDA Forest Service Rocky Mountain impacts of invasive species on the overall Utah State University Research Station (RMRS) is currently engaged structures of plant communities and how well in a 10-year research program to explore how restoration efforts succeed in returning an area invasive species are affecting the grassland, to a desirable plant community. shrubland and desert ecosystems of the western U.S., an area of some 900 million acres in 17 “We expect that these studies will give us western states. “We facilitate and implement a much better understanding of invasive research projects that allow scientists to delve species and how they affect ecosystems,” deeply into many aspects of invasive species,“ says Finch. “A greater understanding of the says Deborah Finch, program manager. “Our science will enhance the ability of natural sponsors and cooperators include the U.S. resource managers to develop and use Department of Agriculture, other federal and management options, balancing social values state government agencies, universities and with management goals, while also taking into foundations, and non-government organizations. account other issues, such as climate change.” Since 2008, we have conducted studies on more than a dozen invasive species. Our scientists The invasive species research is part of a larger also investigate how ecosystems, native long-term research program that is developing species and natural resources are affected by scientific knowledge in five broad focal areas invasions, and what methods and materials can related to western grassland, shrubland, and “Our scientists be developed and applied to repair the damage. desert ecosystems: disturbance (fire, drought, investigate how We will initiate and cooperate on many more etc.); restoration of ecosystems; ecosystems, projects in future years to help us address these and management of ecosystems; the impacts native species issues.” and management implications of climate change; and invasive plant species. Those topics and natural The program focuses on four primary elements, are addressed in other issues of GSDUpdate. resources are spanning from early detection to rehabilitation. More about the program’s efforts on invasive affected by The early detection and rapid response element of species can be found on the GSD website invasions, and the program explores the pathways of invasion, www.fs.fed.us/rm/grassland-shrubland-desert/. what methods such as the factors that leave an area at risk of and materials can invasion. Impact assessment and prioritization be developed and applied to repair the damage.”

Cheatgrass is a priority concern for land managers in the West because not only is it an early-season grower, replacing native plant species like sagebrush, it also alters fire frequency and reduces wildlife habitat quality and land values for farming and ranching. Photo: Bureau of Land Management 2 GSDUpdate

A New Form of Biocontrol: in the fall, and when spring arrives, it is ready to grow to maturity and produce seeds. Native Fungal Pathogens species don’t follow the same pattern, so the One of the most pervasive invasive species in the cheatgrass has little competition from other West is cheatgrass, an annual grass that found plants. During times of drought, cheatgrass can its way here from Eurasia in the late 1800s, most claim all the moisture for itself, before other likely in shipments of wheat. Cheatgrass gets plants have even started growing. its name from farmers The end result is a cheatgrass monoculture – who felt cheated nothing but cheatgrass. And a landscape that is when they learned at high risk of wildfire. that their wheat fields had turned into weeds. Its greatest Cheatgrass is an annual grass that impact has been in the forms tufts up to two feet tall. intermountain region Photo: USDA Forest Service of the interior West. Cheatgrass (Bromus The pathogen Pyrenophora tectorum) has infested semeniperda gets its name, “black fingers of death,” from the black more than 100 million Team BFOD. Photo: USFS acres of land already, projections protruding from killed In addition to Meyer, the research group cheatgrass seeds. but a solution may includes scientists from Gonzaga University soon be in sight. Photo: Susan Meyer in Spokane, Washington, and Brigham Young Twenty years of research at the Rocky Mountain University in Provo, Utah. They have spent Research Station’s Shrub Sciences Laboratory years working to understand why cheatgrass has led to a potential control strategy using a is such a successful invader and how it might fungal pathogen nicknamed the “black fingers be controlled. As part of their research, they of death.” Says Dr. Susan E. Meyer, the research looked at using natural enemies of cheatgrass ecologist leading the studies, “The goal of a to control it – an approach known as biocontrol. practical, safe and cost-effective commercial The most promising agent they have found is a product for cheatgrass biocontrol in now naturally occurring fungus called Pyrenophora within reach.” Sponsors for this research have semeniperda, which can kill dormant cheatgrass included the Joint Fire Sciences Program, the seeds. Killing the dormant, ungerminated seeds Departments of Agriculture and Interior, and is key, because they can lay quiet for two to Idaho Army National Guard. “Currently, three years, giving rise to renewed cheatgrass black fingers Cheatgrass typically invades desert shrublands, infestations long after other eradication of death is the ecosystems that would normally be home to a methods, such as mowing or herbicides, have most promising variety of native plants. It is able to take over seemingly controlled the problem. The scientists control agent such areas in part because of how it reacts to began calling the fungus the black fingers we have.” fire. After a fire occurs, many native species are of death, or BFOD, when they noted the dark slow to recover. Cheatgrass, on the other hand, finger-like growths that emerge from the responds very quickly to the newly opened space dead seeds. and changed soil conditions, rapidly spreading “This pathogen is not completely effective if throughout the area. Once an area has a lot of used alone, but it could be a valuable tool for use cheatgrass, it is at high risk of even more fires; a along with other control methods,” says Meyer. cheatgrass-dominated landscape – a continuous “Currently, black fingers of death is the most carpet of plants that dries out in early summer promising control agent we have.” – is a richer fuel source than the native plants. With more frequent fires, native plants can be The group’s studies have looked at details wiped out entirely. such as: What percentage of dormant seeds is typically killed by BFOD, and how does that The cheatgrass’s reproductive cycle also makes change with habitat and weather changes? How it more likely to spread. Its seeds germinate long can the pathogen persist if there are no

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host seeds? Are some strains of the pathogen two species will interact, given changing more deadly than others? Will the pathogen environments, including those altered by infect other grass species? climate change? And how are the native plants that remain behind after successful biocontrol “Our next steps are to select the more effective responding to a different environment? Are they strains of the pathogen and develop a delivery rebounding once there is no competition from system that is lightweight, economical and invasive species? Several studies funded by effective, and work toward commercially viable RMRS are exploring those questions. biocontrol products,” says Meyer. “To this end, we have applied for a patent for our product, One researcher, for example, is studying the and we also plan to explore whether BFOD is chemical interactions between biocontrol agents effective against other invasive species.” and their invasive host species, to identify the factors that can affect successful biocontrol. In related work, another research group recently “We are finding that biocontrol insects affect funded by the Station’s Competitive Research weed chemistry in very different ways,” says Initiative has started a new study investigating Dr. Justin B. Runyon, a research entomologist some 700 other fungal endophytes that have at the RMRS Biocontrol Research Laboratory been isolated from cheatgrass populations in Bozeman, Montana. “We are finding that across the West. They are studying whether leaf- and root-chewing biocontrol insects cause those endophytes increased or decreased the the weeds to make huge amounts of defensive growth of cheatgrass. They have found that chemicals in leaves, whereas galling insects some do enhance cheatgrass growth, while (those that build structures on the plants) others decrease it. “Understanding these Top and bottom: have little impact on weed chemistry.” When Houndstongue (Cynoglossum officinale relationships, says research plant ecologist weeds produce the defensive compounds, L.) is a poisonous weed that can Dr. Rosemary Pendleton, may lead to a better he explains, they may have fewer resources cause liver damage in livestock, understanding of why cheatgrass is so invasive available for growth or producing seeds, helping resulting in death. and how it can be more effectively managed.” lead to their demise. Runyon notes that in one Photos: Mary Ellen Harte study, he “tricked” houndstongue plants into producing defensive chemicals even without Classical Biocontrol with insects; instead, he applied a plant hormone. “Our goal is to isolate and determine what role Insects: New Questions Emerging

Classical biocontrol – the use of imported natural enemies such as insects to control a non-native invasive pest species – can be a very effective tool for controlling weed infestations. However, despite some spectacular successes, outcomes are often inconsistent or Photo: Sharlene Sing unpredictable. Much of the research done in the past focused on finding insect species that act The toadflax stem-mining weevil known asMecinus on particular invasive species, rather than on janthinus has often been used to control Dalmatian and predicting the effectiveness of such programs yellow toadflax species. or understanding the broader ecosystem effects that might occur once the insects were released. these defense mechanisms play in successful Much more research is needed to explore and biocontrol, and to see if the success of better understand potential biocontrol agents biocontrol agents can be related to the defenses and how they will interact with their target they induce.” species and the community as a whole. Another research entomologist, Dr. Sharlene Among the questions that need to be addressed: E. Sing, also at the RMRS Bozeman Biocontrol Which agents are best suited for use with Research Laboratory, is looking at what which invasive species, based on their biology, happens when species evolve or otherwise adapt ecology and the potential interactions between to new environments, in the context of weed the species? How can we better predict how biocontrol. “Classical weed biological control 4 GSDUpdate

pairs biocontrol agents (non-native insects) Other Projects: Fire, Birds, with exotic plant species that have become invasive,” she says. Typically, these pairs co- Seeds and More evolved and are well suited to each other; the Many other research projects funded by insects have evolved to consume the plants in RMRS are also helping to fill in the missing one way or another. But what happens if the pieces of the invasive species puzzle. Each invasive plants have undergone some form of one, in its own way, will contribute to a fuller adaptation? Will the insects still be able to find understanding of the science of various species and control them? Sing’s research is looking and their relationships. Ultimately, this body of at improving biological control of two invasive information will help natural resource managers species, yellow or common toadflax (Linaria to develop better management options, leading Leafy spurge invades prairies, vulgaris) and Dalmatian toadflax (L. dalmatica). to better control of invasives and the restoration pastures and other open areas The toadflax stem-mining weevil known as and is major pest in national of western ecosystems to a more natural state. parks and preserves. Mecinus janthinus, a biocontrol agent, has often been used to control both species. But • Several studies are looking at the intersection Photo: Jack Butler now a hybrid invasive species, hybrid toadflax, of invasive species, fire and restoration. has developed as a result of cross-pollination Over the last century, riparian communities between the two invasive plants. In addition, along the Middle Rio Grande in New Mexico genetically distinct biotypes of the weevil have have become increasingly dominated by been found in association with the two original the invasive species salt cedar (Tamarix invasive toadflax species. What do all of these ramosissima) and Russian olive (Elaeagnus new variations mean for biocontrol? Are the angustifolia). These woody plants have new weevil biotypes effective only against greatly altered the structure of these certain toadflax species? Will any of them be vegetative communities, and have increased effective against the hybrid toadflax? Is there the frequency and severity of wildfires. some other biotype of the weevil that might Native tree species, such as the Rio Grande more effective? Sing’s research hopes to tease cottonwood (Populus deltoides ssp. wislizeni) out these complex relationships, resulting in a and Goodding’s willow (Salix gooddingii), biocontrol project that addresses these genetic unfortunately, do not resist fire damage well complexities. and do not regenerate very successfully after fire. This increased fire danger has led to And what happens after a successful biocontrol a number of fuel reduction (exotic tree and program? Few long-term studies have looked debris removal) projects as well as studies at how resident native plants respond when on the potential effects on wildlife, vegetation competing invasive weeds are suppressed. and groundwater. For example, a long-term Research ecologist Dr. Jack L. Butler is RMRS project is looking at the effects of fuel studying how native vegetation has responded reduction treatments along several reaches to suppression of leafy spurge (Euphorbia of the Rio Grande, and how they might affect esula L.), an aggressive weed. He has found, bird populations. The goal is to identify the for example, that while the total abundance fuel reduction practices that will preserve of the native vegetation did increase after native species, reduce catastrophic fire risk, leafy spurge control, other factors did not and have the least impact on native wildlife improve. The relative abundance of the native species. Related studies are seeking to assess species remained lower than that of the non- the immediate and long-term responses of native species, and in fact, other non-native plants, animals and water to wildfire, to better species essentially replaced leafy spurge as understand how ecosystems respond to fire, the dominant species. “This study highlights the need to treat new infestations as soon as possible, to avoid the long-term residual effects of large contributions to the seed bank, native species loss and ecosystem modification,” says Butler. Musk thistle, an invader of the Black Hills, is an aggressive weed in pastures, rangelands and roadsides. Because it reproduces solely Photo: John M. Randall, from seed, the key for successful management The Nature Conservancy is to prevent seed production. 5 GSDUpdate

to compare invaded fire-prone ecosystems on problem. Have you accidentally introduced the Middle Rio Grande to those relatively free a hitchhiking exotic plant seed, pathogen or of invasives, and to aid in the development of virus from your travels abroad? Could you be ecosystem management practices. spreading invasive species as a boater, hiker, horseback rider, biker or angler? Have your • Ponderosa forests of the Black Hills are off-road vehicle explorations disturbed soils also at high risk for high-severity fires, due to and plants, opening the area for invasions? changes in the historic fire regime. After the Learn what local programs are in place to 2000 Jaspar fire, the largest fire in the history combat the problem. of the Black Hills National Forest of South Dakota, RMRS researchers began studying The National Invasive Species Council offers how the severity of different burns may some practical tips: influence where non-native plants show up. A manager armed with this knowledge will be • Clean hiking books, waders, boats and better equipped to detect and control weeds trailers, and off-road vehicles and other following a fire. Similarly, RMRS ecologist pathways of spread to stop hitchhiking Seeds of invasive plants catch on Stefanie Wacker is examining responses of invasive species hiking boots, which transport them native and invasive plants to disturbances to new areas to invade. • Use certified “weed-free” forage, firewood, from timber harvest; she plans to use her hay, mulch and soil Photo: Alan Cleaver results in a Ph.D. dissertation at South Dakota State University. • Don’t dump live bait into waterways

• The Great Basin Native Plant Selection & • Remove invasive plants from your land Increase Project, with funding from Bureau of Land Management’s Great Basin Restoration • Plant non-invasive plants in your garden Initiative, is working on several fronts to increase the availability of native plant seeds • Care for aquarium fish and other pets properly and foster successes in restoring native plant so they don’t become invasive communities across the Great Basin. Some 20 different groups in ten states are working on various projects. Among their goals are an Bozeman Biocontrol Lab increased understanding of genetic variability in native species; identifying pollinators, seed Renovation – Almost Done! predators and plant diseases; developing An extensive renovation of the RMRS Bozeman management strategies to enhance Biocontrol Research Laboratory, which is agricultural seed production; and transferring administered by GSD, is nearly complete. their research results to seed growers and land managers. The main building is being modernized with a new heating system, restrooms, lighting and finishes. There is also new state-of-the art What Can You Do About Invasive research equipment, including two growth chambers, a fume hood and other lab and Species? greenhouse apparatus. Outside, the building has been restored to its original 1962 style. Learn more about invasive species in your An RMRS Sustainable Operations microgrant, area. Check out the National Invasive Species awarded to Dr. Justin Runyon, will be used to Council website, at www.invasivespecies.gov. install pollinator-friendly, drought-tolerant Illustration of the renovated RMRS The site holds an extensive list of background Bozeman Biocontrol Research landscaping, further enhancing the exterior. information, including fact sheets and Laboratory at the Montana State University campus in Bozeman, photographs, resources for land managers and The nearby warehouse building has also been Montana. teachers, and more. Your local Cooperative upgraded, with a new roof, siding, insulation and Extension office may also have information on lighting. Both buildings will also have updated invasive species that are a problem in your area. safety and handicap features, as well as energy- You can find your local office at www.nifa.usda. saving measures. gov/Extension/USA-text.html. Also consider how your activities might be contributing the 6 GSDUpdate

Meet Some of the GSD Scientists Dr. Justin Runyon is a research entomologist Dr. Jack Butler is a stationed at the RMRS research ecologist at the Bozeman Biocontrol lab RMRS Forest and Grassland who conducts research Research Laboratory in on biological control of Rapid City, South Dakota. invasive plants. He is His research addresses involved in the search for invasive species impacts, and the evaluation, approval and monitoring biological control of invasive of exotic natural enemies (usually insects) species and range ecology. He works with for the suppression of invasive weeds. A goal managers in the northern Great Plains to help of his research is to understand and predict identify effective methods and practices for the outcomes of biocontrol introductions by sustaining rangelands, including populations of applying the chemical ecology of plant-insect A message from the native plant and animal species. He has hosted interactions to classical biological control of several workshops on black-tailed prairie weeds – two fields that have largely progressed Program Manager dogs and livestock management, and he seeks independently to date. solutions for eradicating exotic plants such as Invasive Species is one of five leafy spurge and sickleweed and restoring native Dr. Sharlene Sing, stationed focal areas of the Grassland, plant communities. at the RMRS Weed Shrubland and Desert Biocontrol Lab in Bozeman, Ecosystems Science Program Dr. Susan Meyer is a Montana, works on many (GSD). Our program mission research ecologist stationed collaborative studies to is to develop and deliver at the RMRS Shrub improve the efficacy and knowledge and tools that will Sciences Laboratory, Provo, safety of classical weed help to sustain and restore Utah. Her work focuses on biological control. One grasslands, shrublands and the regeneration biology study aims at determining if toadflax biocontrol deserts threatened by invasive of native intermountain agents exhibit differential responses to yellow species, disturbances, urban shrubs, forbs and grasses, x Dalmatian toadflax hybrids vs. either of the pressures and climate change. in the context of the ecological restoration parental toadflax species. She has engaged Scientists in our program study of shrublands, including the study of within- in long-term pre- and post-biocontrol release the physiological, behavioral and species genetic variation in germination monitoring projects on yellow and Dalmatian demographic responses of plants regulation and seedling establishment ecology. toadflax, leafy spurge, salt cedar and Russian and animals to invasions by She also works on the biology and pathogen olive. Also, she is assessing the potential for non–native species, especially in control of the exotic annual grass cheatgrass. integrating herbicide treatments and with other stressors control of Dalmatian toadflax on prescribed such as fire and climate change. Dr. Rosemary Pendleton is a burn-treated . Our research also evaluates the research ecologist stationed capacity for species to adapt at the Forestry Sciences Stefanie Wacker is a Ph.D. to environmental changes. We Laboratory in Albuquerque, student at the Geographic provide decision support by New Mexico. Her current Information Science Center developing new plant materials research focuses on of Excellence, South for use in restoring ecosystems reproductive biology and Dakota State University, under stress, guidance for establishment ecology Brookings, and is also identifying ecosystems at of native plant species. She has studied the employed as an ecologist risk from invasive species, effects of fire on grassland vegetation and soil by RMRS under the Student and assessments and tools properties, including perennial grass recovery, Career Experience Program authority. She is for determining species and biodiversity, floral resources for pollinators, stationed at the Forest and Grassland Research ecosystem vulnerability. soil microtopography and biological soil crust Laboratory in Rapid City, South Dakota. Her function. She is also investigating the biology Ph.D. research is evaluating the effects of —Dr. Deborah Finch, and control of cheatgrass using endophytes, timber harvesting on understory invasive and Science Program Manager and the reproductive biology and gene flow in native plant species of ponderosa pine forests in creosote bush (Larrea tridentata) at the the Black Hills of South Dakota. northern ecotone.

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Recent GSD Publications Chambers, J.C., Leger, E., Goergen, E. 2009. Cold desert fire and invasive species management: Bateman, H.L., Chung-MacCoubrey, A., Finch, Resources, strategies, tactics, and response. D.M., Snell, H.L., Hawksworth, D.L. 2008. Impacts Rangelands. 31(3):14-20. of non-native plant removal on vertebrates along D’Antonio, C.M., Chambers, J.C., Loh, R., Tunison, the Middle Rio Grande (New Mexico). Ecological J.T. 2009. Applying ecological concepts to the Restoration. 26:193-195. management of widespread grass invasions Beckstead, J., Meyer, S.E., Connolly, B.M., Huck, [Chapter 7]. In: Inderjit, R.L., ed. Management of M.B., Street, L.E. 2010. Cheatgrass facilitates Invasive Weeds. Netherlands: Springer. p. 123-149. spillover of a seed bank pathogen onto native grass Gunderson-Izurieta, S., Markin, G.P., Reedy, N., species. Journal of Ecology. 98:168-177. Frieberg. 2009. Southern Idaho student “bug Beckstead, J., Street, L.K., Meyer S.E., Allen P.S. crews”: weeds, youth, and biocontrol in the Cottonwood is often killed by 2011. Fire effects on the cheatgrass seed bank rangelands of Idaho. Rangelands. 31:36-40. fire, but invasive salt cedar resprouts and spreads, as seen pathogen. Pyrenophora semeniperda. Rangeland Markin, G.P. 2009. Passiflora mollissima (HBK) here after a Rio Grande fire. Ecology and Management. 64:148-157. Bailey (Passifloraceae). Biological Control of Tropical Photo: USDA Forest Service Birdsall, J., Markin, G. 2010. Biological Control Weeds using Arthropods. Eds.: R. Muniappan, G.V.P. of Yellow Starthistle (Centaurea solstitialis) in the Reddy, & A. Raman. Cambridge University Press. p. Salmon River Canyon of Idaho. Invasive Plant 319-331. Science and Management. 3:462-469. Mazzola, M.B., Chambers, J.C., Blank, R.R., Pyke, Birdsall, J., McCaughey, W., Runyon, J.B. 2011. D.A., Schupp, E.W., Allcock, K.G., Doescher, P.S., Roads impact the recruitment and distribution Nowak, R.S. 2010. Effects of resource availability of noxious weeds more than restoration and propagule supply on native species recruitment treatments in a lodge pole pine forest in Montana, in sagebrush ecosystems invaded by Bromus USA. . DOI: 10.1111/j.1526- tectorum. Biological Invasions: DOI: 10.1007/s10530- 100X.2011.00781. 010-9846-0. Butler, J.L., Wacker, S.D. 2010. Lack of native vegetation recovery following biological control of leafy spurge. Rangeland Ecology and Management. 63:553-563.

Field crews measure tamarisk structure before control treatments. Photo: USDA Forest Service

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Program Manager Meyer, S.E., Nelson D.L., Clement S. 2010. The Schat, M., Sing, S.E., Peterson, R.K.D., Menalled, Grassland, Shrubland and ecological genetics of the Ustilago bullata-Bromus F.D., Weaver, D.K. 2011. Growth inhibition of Desert Ecosystems Science tectorum pathosystem: A role for frequency- Dalmatian toadflax Linaria dalmatica (L.) Miller, in Deborah Finch, Ph.D. dependent selection? American Journal of Botany. response to herbivory by the biological control agent 97:1304-1312. Meeinus janthinus Germar. Journal of Entomological USDA Forest Service Science. 47:232-246. Rocky Mountain Research Station Meyer, S.E., Stewart T.E., Clement S. 2010. The quick and the deadly: growth versus virulence in a Scott J.W., Meyer S.E., Merrill K.R., Anderson, V.J. 333 Broadway SE, Suite 115 seed bank pathogen. New Phytologist. 187:207-216. 2010. Local population differentiation in Bromus Albuquerque, NM 87102 tectorum L. in relation to habitat specific selection Pendleton, R.L., Pendleton, B.K., Finch, D.M. regimes. Evolutionary Ecology. 24:1061-1080. voice 505-724-3671 2011. Displacement of native riparian shrubs by fax 505-724-3688 woody exotics: Effects on arthropod and pollinator Sing, S.E., Peterson, R.K.D. 2011. Assessing cell 505-401-0580 community composition. In: Wambolt, C.L., et al, environmental risks for establishing invasive www.fs.fed.us/rm/grassland- comps. Proceedings of the 15th wildland shrub species Dalmatian (Linaria dalmatica) and yellow (L. shrubland-desert/ symposium; June 17-19, 2008; Bozeman, MT. vulgaris) toadflax in North America. International Natural Resources and Environmental Issues. 16: Journal of Environmental Research and Public Health. www.fs.fed.us/rm/albuq/dfinch.php Article 25. 8:2823-2853. Progar, R.A., Markin, G., Milan, J., Barbouletos, T., Smith, D.M., Finch, D.M., Gunning, C., Jemison, R., Rinella, M.J. 2010. Inundative release of Aphthona Kelly, J.F. 2009. Post-wildfire recovery of riparian spp. flea beetles (Coleoptera: Chrysomelidae) as vegetation during a period of water scarcity in Writer/Editor a biological “herbicide” on leafy spurge in riparian the southwestern USA. Fire Ecology Special Issue. Catherine Dold areas. Journal of Economic Entomology. 103:242-248. 5(1):38-55. [email protected] Runyon, J.B., Mescher, M.C., Felton, G.W., Wacker, S.D., Butler, J.L. 2006. Potential impact of www.catherinedold.com De Moraes C.M.. 2010. Parasitism by Cuscuta two Aphthona spp. on a native, nontarget Euphorbia pentagona sequentially induces JA and SA defense species. Rangeland Ecology and Management. pathways in tomato. Plant Cell & Environment. 59:468-474. Design/Layout 33:290-303. Ward, S.M., Fleischmann, C.E., Turner, M.F., Andrew Schlabach Runyon, J.B., Mescher, M.C., De Moraes, C.M. Sing, S.E. 2009. Hybridization between invasive [email protected] 2010. Plant defenses against parasitic plants show populations of Dalmatian toadflax (Linaria similarities to those induced by herbivores and dalmatica) and yellow toadflax (Linaria vulgaris). pathogens. Plant Signaling and Behavior. 5:929-931. Invasive Plant Science and Management. 2:369-378. Publications are available online in TreeSearch: www.treesearch.fs.fed.us. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, DC 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.

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