Invasive Species
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The Western Governors’ Association (WGA) has addressed this need by surveying invasive species coordinators in WGA member states and territories Top 50 Invasive Species in the West to develop the “Top 50 Invasive Species in the West.” The compilation of terrestrial and aquatic invasive species includes highly-publicized examples such as cheatgrass, Quagga Mussels, tamarisk and the Emerald Ash Borer. The list also encompasses less well known, but still impactful, examples such as leafy spurge, Red shiner, Russian knapweed, and Golden algae.
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Though widely distributed throughout the study region, ventenata only appeared in 45% of the 225 plots, and foliar cover was typically less than 50%. It was primarily found in ephemerally wet microhabitats. Species richness and the Shannon diversity index were lowest in plots with high V. dubia cover. Nonmetric multidimensional scaling analysis revealed that ventenata and medusahead were closely associated. Furthermore, chi-square indicator analysis showed that T. caput-medusae was more prevalent, while mountain big sagebrush was less prevalent, in plots containing ventenata. Abiotic factors that explained variation in ventenata abundance included rock cover, soil depth, and a north/south aspect. Higher ventenata cover also correlated with higher clay content and lower phosphorus and potassium concentrations in the soil. We suggest that at this point, detection survey efforts to locate incipient infestations of ventenata in sagebrush steppe communities should focus on moist areas and sites susceptible to invasion by medusahead.
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USGS scientists Lea Condon and David Pyke tested the idea that biotic communities mediate the effects of disturbances such as fire and grazing on site resistance by using structural equation modeling to test relationships between disturbance events, the biotic community, and resistance to cheatgrass invasion. Increased site resistance following fire was associated with higher bunchgrass cover and recovery of bunchgrasses and mosses with time since fire. Fire reduced near-term site resistance to cheatgrass on actively grazed rangelands, and evidence of grazing was more pronounced on burned sites and was positively correlated with cheatgrass cover. Independent of fire, grazing impacts resulted in reduced site resistance to cheatgrass, suggesting that grazing management that enhances plant and biocrust communities will also enhance site resistance.
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This report found that treating low infestations across all three levels of forage production yields a financial gain, ranging from 21 cents to $4.94 per acre. However, treating highly infested areas showed a financial loss of $3.76 to $5.43 per acre, despite the level of forage production. Moderate infestations showed a financial gain with treatment only on sites producing 1,000 or 1,500 pounds per acre of forage.
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Cheatgrass is now found in at least 49 states, although it’s mainly a problem in the semi-arid Great Basin — which stretches across portions of Utah, Nevada, Idaho, Oregon, and California — since its adapted to thrive in areas with wet winters and hot, dry summers. People are now used to seeing cheatgrass-dominated landscapes, but it’s not what we should see.
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This webinar discusses the process as well as take home messages from area-wide demonstration projects on cheatgrass reduction. Roger Sheley, USDA ARS, presented.
This webinar was the last in our 2018 Webinar Series: Moving the Needle on Cheatgrass: Putting What We Know into Practice.
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Brian Mealor, Associate Professor and Director of the Sheridan Research and Extension Center, UW, discusses strategic opportunities where land managers can intervene to move the needle on cheatgrass. It describes the level of invasion and management strategies applicable to each. Then, Mike Pellant, Ecologist, Retired BLM, discusses post-fire opportunities, cheatgrass die-off areas, and the myths and realities of dormant season targeted grazing.
This webinar was the fourth in our 2018 Webinar Series: Moving the Needle on Cheatgrass: Putting What We Know into Practice.
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This webinar discusses the benefits of altering timing of grazing to reduce annuals and maintain perennial bunchgrasses. It also discusses the detrimental impacts of repeated spring defoliation on perennials. Kirk Davies, Lead Rangeland Scientist with USDA ARS, presented.
This webinar was the third in our 2018 Webinar Series: Moving the Needle on Cheatgrass: Putting What We Know into Practice.
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This webinar covers existing products that are effective and how they are applied in different situations. It will also introduce new emerging herbicides. Richard D. Lee, Integrated Pest Management Specialist, BLM National Operations Center, presents.
This webinar was the second in our 2018 Webinar Series: Moving the Needle on Cheatgrass: Putting What We Know into Practice.
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Reducing cheatgrass has been a primary research topic and goal of ecological restoration for over 50 years. Our work examined published studies between 1946 and 2012 to identify how a broad range of control methods influence cheatgrass and perennial grass abundance. Based on this assessment, we identify obstacles encountered in achieving desired restoration and clarify what research is needed to develop improved mechanistic control strategies. Jeremy Maestas, Ecologist, USDA-NRCS, and Tom Monaco, Ecologist at USDA-ARS and USU, present.
This webinar is the first in our 2018 Webinar Series: Moving the Needle on Cheatgrass: Putting What We Know into Practice.