The Colorado Plateau Native Plant Program Database (CPNPP)

Russian knapweed restoration seeding trials

Project #: 508340  –   Updated: December 19, 2016


Andrea Kramer, 2016. BONDERMAN FIELD STATION AT RIO MESA RUSSIAN KNAPWEED RESTORATION: NATIVE WINNER SEEDING TRIALS. November 2013 - May 2016. Chicago Botanic Garden, with support from the Bureau of Land Management Plant Conservation Program.

Project Summary

Located in Grand County, Utah the Bonderman Field Station at Rio Mesa is located along the red rock country of the Dolores River. It is owned and managed by the University of Utah. The project site has abandoned agricultural fields that by 2013 had become invaded with Russian knapweed (Acroptilon repens), which has outcompeted much of the native vegetation at the site. In 2013, funding from the USFWS Partners for Wildlife program and the University was used to treat and restore the knapweed site (about 42 acres of riparian and upland habitat). They hired a contractor to carry out herbicide application and seeding, using native, commercially available seeds in 2013. The size of the site that was treated is about 42 acres of riparian and upland habitat. We took advantage of the opportunity to incorporate an experimental approach to this restoration, and tested how the use of different native plant materials can impact the long-term outcomes of the restoration. Very little is known about which native species are most appropriate for post-knapweed restoration work like this, but most of the published literature is focused on 3-5 non-native species. Building on research that has shown evolution of native species in knapweed-infested habitat and better suppression of invasive species when a diverse mix of species (including forbs) is sown into the restoration site, we expect that post-knapweed seeding will be most effective if it contains a diverse mix of native species and seed sources that are suited for the restoration site. Our research goal was to test which native plant materials (species, sources, and mixes of species/seed sources) are most effective at long-term suppression of knapweed following herbicide treatment.

Project Conclusions

Two years post-treatment, there was less cover of the target invasive species (Russian knapweed) in the seeded treatments than the unseeded treatments, and no significant difference between the herbicided and unherbicided treatments. The local seed mix tended to have lower cover of knapweed than the standard seed mix, but this was not a significant difference. However, it is interesting to consider potential causes of the seeding effects – while there was again no significant difference between the standard and local mix treatments in measures of native or non-native cover, the standard seed mix plots tended to have greater percent cover than local plots. This suggests that belowground processes may be impacting the cover of knapweed more than aboveground processes, and warrants further investigation.


Targeted habitats:

    • Shrublands and Grasslands
      • Shrublands and Steppe
    • Special Types
      • Cliff and Canyon

Targeted species:

  • Bottlebrush Squirrel-tail Elymus elymoides
  • Needle-and-Thread Hesperostipa comata
  • Great Basin Lyme Grass Leymus cinereus
  • Blue Gramma Bouteloua gracilis
  • Indian Mountain-ricegrass Achnatherum hymenoides
  • James' Galleta Pleuraphis jamesii
  • Streamside Wild Rye Elymus lanceolatus
  • Alkali Sacaton Sporobolus airoides
  • Sand Dropseed Sporobolus cryptandrus
  • Russian Knapweed Acroptilon repens

Study Type

Experimental seeding trials within larger invasive species treatment and seeding

Public Access

Site Name Publicly Accessible
Site 1 No

Additional Information

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Colorado Plateau Native Plant Program (CPNPP)
(Non-Governmental Organization)

Primary Contact

Andrea Kramer
Chicago Botanic Garden
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  • Bonderman Field Station at Rio Mesa

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