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Invasive Species Ecology Completed

By Forest and Rangeland Ecosystem Science Center November 13, 2017

Invasive annual grasses are the greatest threat to shrub-grassland ecosystems of the Intermountain West. These grasses grow earlier in the season than native plants, usurping water and nutrients, and making survival and reproduction difficult for native species. They also change the fire regime within the ecosystem, creating more frequent and larger wildfires. We are attempting to understand the environmental conditions that may lead to the ultimate dominance of these annual grasses in order to provide early warning indicators before conversions from native shrub grasslands shift to annual grasslands.

Below are other science projects associated with this project.

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truck and camper trailer Onaqui SageStep field site

Restoration and Ecology of Arid Lands Team (FRESC)

The focus of our research is on the restoration and monitoring of the plants and soils of the Intermountain West. Our lab is part of the Snake River Field Station, but is located in Corvallis, Oregon. Research topics include fire rehabilitation effects and effectiveness, indicators of rangeland health, invasive species ecology, and restoration of shrub steppe ecosystems.
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Ecosystems Mission Area, Land Management Research Program, Forest and Rangeland Ecosystem Science Center
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Restoration and Ecology of Arid Lands Team (FRESC)

The focus of our research is on the restoration and monitoring of the plants and soils of the Intermountain West. Our lab is part of the Snake River Field Station, but is located in Corvallis, Oregon. Research topics include fire rehabilitation effects and effectiveness, indicators of rangeland health, invasive species ecology, and restoration of shrub steppe ecosystems.
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Below are publications associated with this project.

Land uses, fire, and invasion: Exotic annual Bromus and human dimensions

Human land uses are the primary cause of the introduction and spread of exotic annual Bromus species. Initial introductions were likely linked to contaminated seeds used by homesteading farmers in the late 1880s and early 1900s. Transportation routes aided their spread. Unrestricted livestock grazing from the 1800s through the mid-1900s reduced native plant competitors leaving large areas vulnerab
Authors
David A. Pyke, Jeanne C. Chambers, Jeffrey L. Beck, Matthew L. Brooks, Brian A. Mealor
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Stress-gradient hypothesis explains susceptibility to Bromus tectorum invasion and community stability in North America's semi-arid Artemisia tridentata wyomingensis ecosystems

Questions: (1) What combinations of overlapping water and heat stress and herbivory disturbance gradients are associated with shifts in interactions between Artemisia tridentata subsp. wyomingensis (Artemisia) and herbaceous beneficiary species? (2) Do interactions between Artemisia and beneficiaries shift from competition to facilitation with increasing stress-disturbance where facilitation and c
Authors
Michael D. Reisner, Paul S. Doescher, David A. Pyke
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Herbivores and nutrients control grassland plant diversity via light limitation

Human alterations to nutrient cycles and herbivore communities are affecting global biodiversity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we
Authors
Elizabeth T. Borer, Eric W. Seabloom, Daniel S. Gruner, W. Stanley Harpole, Helmut Hillebrand, Eric M. Lind, Peter B. Alder, Juan Alberti, T. Michael Anderson, Jonathan D. Bakker, Lori Biederman, Dana Blumenthal, Cynthia S. Brown, Lars A. Brudvig, Yvonne M. Buckley, Marc Cadotte, Cheng-Jin Chu, Elsa E. Cleland, Michael J. Crawley, Pedro Daleo, Ellen Ingman Damschen, Kendi F. Davies, Nicole M. DeCrappeo, Guozhen Du, Jennifer Firn, Yann Hautier, Robert W. Heckman, Andy Hector, Janneke HilleRisLambers, Oscar Iribarne, Julia A. Klein, Johannes M.H. Knops, Kimberly J. La Pierre, Andrew D.B. Leakey, Wei Li, Andrew S. MacDougall, Rebecca L. McCulley, Brett A. Melbourne, Charles E. Mitchell, Joslin L. Moore, Brent Mortensen, Lydia R. O'Halloran, John L. Orrock, Jesús Pascual, Suzanne M. Prober, David A. Pyke, Anita C. Risch, Martin Schuetz, Melinda D. Smith, Carly J. Stevens, Lauren L. Sullivan, Ryan J. Williams, Peter D. Wragg, Justin P. Wright, Louie H. Yang
By
Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Forest and Rangeland Ecosystem Science Center

Nitrogen limitation, 15N tracer retention, and growth response in intact and Bromus tectorum-invaded Artemisia tridentata ssp. wyomingensis communities

Annual grass invasion into shrub-dominated ecosystems is associated with changes in nutrient cycling that may alter nitrogen (N) limitation and retention. Carbon (C) applications that reduce plant-available N have been suggested to give native perennial vegetation a competitive advantage over exotic annual grasses, but plant community and N retention responses to C addition remain poorly understoo
Authors
Dana L. Witwicki, Paul S. Doescher, David A. Pyke, Nicole M. DeCrappeo, Steven S. Perakis
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Effects of resource availability and propagule supply on native species recruitment in sagebrush ecosystems invaded by Bromus tectorum

Resource availability and propagule supply are major factors influencing establishment and persistence of both native and invasive species. Increased soil nitrogen (N) availability and high propagule inputs contribute to the ability of annual invasive grasses to dominate disturbed ecosystems. Nitrogen reduction through carbon (C) additions can potentially immobilize soil N and reduce the competiti
Authors
Monica B. Mazzola, Jeanne C. Chambers, Robert R. Blank, David A. Pyke, Eugene W. Schupp, Kimberly G. Allcock, Paul S. Doescher, Robert S. Nowak
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Abundance of introduced species at home predicts abundance away in herbaceous communities

Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countri
Authors
Jennifer Firn, Joslin L. Moore, Andrew S. MacDougall, Elizabeth T. Borer, Eric W. Seabloom, Janneke HilleRisLambers, W. Stanley Harpole, Elsa E. Cleland, Cynthia S. Brown, Johannes M.H. Knops, Suzanne M. Prober, David A. Pyke, Kelly A. Farrell, John D. Bakker, Lydia R. O'Halloran, Peter B. Adler, Scott L. Collins, Carla M. D'Antonio, Michael J. Crawley, Elizabeth M. Wolkovich, Kimberly J. La Pierre, Brett A. Melbourne, Yann Hautier, John W. Morgan, Andrew D.B. Leakey, Adam Kay, Rebecca McCulley, Kendi F. Davies, Carly J. Stevens, Cheng-Jin Chu, Karen D. Holl, Julia A. Klein, Phillip A. Fay, Nicole Hagenah, Kevin P. Kirkman, Yvonne M. Buckley
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Defoliation effects on Bromus tectorum seed production: Implications for grazing

Cheatgrass (Bromus tectorum L.) is an invasive annual grass that creates near-homogenous stands in areas throughout the Intermountain sagebrush steppe and challenges successful native plant restoration in these areas. A clipping experiment carried out at two cheatgrass-dominated sites in eastern Oregon (Lincoln Bench and Succor Creek) evaluated defoliation as a potential control method for cheatgr
Authors
K. Hempy-Mayer, D.A. Pyke
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Biotic soil crusts in relation to topography, cheatgrass, and fire in the Columbia Basin, Washington

We studied lichen and bryophyte soil crust communities in a large public grazing allotment within a sagebrush steppe ecosystem in which the biotic soil crusts are largely intact. The allotment had been rested from grazing for 12 years, but experienced an extensive series of wildfires. In the 350, 4 x 0.5 m plots, stratified by topographic position, we found 60 species or species groups that can be
Authors
Jeanne Ponzetti, B. McCune, David A. Pyke
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Effects of invasive alien plants on fire regimes

Plant invasions are widely recognized as significant threats to biodiversity conservation worldwide. One way invasions can affect native ecosystems is by changing fuel properties, which can in turn affect fire behavior and, ultimately, alter fire regime characteristics such as frequency, intensity, extent, type, and seasonality of fire. If the regime changes subsequently promote the dominance of t
Authors
M.L. Brooks, C. M. D'Antonio, D.M. Richardson, J.M. DiTomaso, J.B. Grace, R.J. Hobbs, J. E. Keeley, M. Pellant, D. Pyke
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center

Mixed-density designs for evaluating plant interactions during revegetation

No abstract available.
Authors
Mark G. Francis, David A. Pyke
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Crested wheatgrass-cheatgrass seedling competition in a mixed-density design

Plant competition experiments have historically used designs that are difficult to interpret due to confounding problems. Recently, designs based on a 'response function' approach have been proposed and tested in various plant mixture settings. For this study, 3 species were used that are important in current revegetation practices in the Intermountain West. 'Nordan' (Agropyron desertorum [Fish. e
Authors
Mark G. Francis, David A. Pyke
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center