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United States Department of Agriculture

Agricultural Research Service

Research Project: Investigations of Seed and Seeding Ecology and Competitive Ability of Native Annual Forbs of the Western Great Basin

Location: Great Basin Rangelands Research

2011 Annual Report


1a.Objectives (from AD-416)
To investigate (1) the potential for Great Basin native annual forbs to effectively compete with B. tectorum and facilitate the establishment success of native perennial grasses (2) the germination ecology of key Great Basin native annual forbs. The ultimate goal of this work is to determine whether it would be useful to include native annuals in postfire rehabilitation seed mixes.


1b.Approach (from AD-416)
1. Greenhouse competition study: This aspect of the research is being conducted in combination with Dr. Elizabeth Leger and Dr. Erin Goergen at UNR. We have completed one greenhouse experiment to look at competition of the two native species with Bromus tectorum and establishment of Elymus multisetus with native annual forbs, with Bromus tectorum, and with annual forb-B. tectorum mix. Growing with competitors decreased the size of Elymus multisetus, however the largest decrease in size was found when grown with Bromus tectorum and Amsinckia tesselata. In contrast, Elymus multisetus grew best with Mentzelia veatchiana. When in competition with Bromus tectorum, Elymus multisetus performed best when Mentzelia veatchiana was also present. These results support the idea that the presence of certain native annual forbs can enhance the establishment of Elymus multisetus in Bromus tectorum invaded rangelands. 2. Buried seed bank experiments for Amsinckia tesselata, Amsinckia intermedia, Blepharipappus scaber, and Mentzelia veatchiana: For each species, we prepared artificial seed bank buried bags. Bags are being retrieved monthly for one year, then in early spring and late summer for up to 5 years or until there is no evidence of seed carryover. For each bag, the number of recently field-germinated seeds, seeds germinable at 2/15°C for 4 weeks are being determined. 3. Field competition study: This experiment also is being conducted in combination with Dr. Elizabeth Leger and Dr. Erin Goergen at UNR. Last year, we planted small plots with combinations of native annuals and Bromus tectorum. The experiment looks at the performance of Bromus tectorum or Elymus multisetus target plants in annual native forb monocultures, Bromus tectorum monoculture, or a mixture of annual native forbs and Bromus tectorum.


3.Progress Report

This research is in support of Objective 2 of the in-house project, “Devise management guidelines, technologies, and practices for conserving and restoring Great Basin rangelands”. The goals of this work are to investigate (1) the potential for Great Basin native annual forbs to effectively compete with Bromus tectorum and facilitate the establishment success of native perennial grasses (2) the germination ecology of key Great Basin native annual forbs. The ultimate goal of this work is to determine whether it would be useful to include native annuals in postfire rehabilitation seed mixes. This aspect of the research is being conducted in combination with University Nevada, Reno (UNR). During this FY, results from two greenhouse experiments using a hybrid additive/replacement design to look at competition of the two native species with Bromus tectorum and establishment of Elymus multisetus with native annual forbs, with B. tectorum, and with annual forb-B. tectorum mix are being written up for a manuscript. Growing with competitors decreased the size of E. multisetus, however the largest decrease in size was found when grown with B. tectorum and Amsinckia tesselata. In contrast, E. multisetus grew best with Mentzelia veatchiana. When in competition with B. tectorum, E. multisetus performed best when M. veatchiana was also present. These results support the idea that the presence of certain native annual forbs can enhance the establishment of E. multisetus in B. tectorum invaded rangelands. The experiment is in its second year of the project and manuscripts are being prepared on progress and meeting milestones. Results from this study also indicated that both native annual forbs examined are negatively impacted by growth with B. tectorum, but M. veatchiana was more impacted than A. tesselata. Monitoring is accomplished through meetings with collaborators to assess status of the project and make corrections to the research approach as required to meet the goals of the project. Results are now being prepared as a manuscript.


Last Modified: 12/20/2014
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