by Maggie Meehan

The Shubert Lab, located at the Denver Botanic Gardens (DBG) is supervised by Dr. Anna Sher, Director of Research at the Gardens and Associate Professor at University of Denver (DU). This unique collaboration affords students from local universities (including DU, UC-Denver, and others) the opportunity to work together with DBG and government agencies on ecological restoration research.
Dr. Sher is most known for her work on saltcedar (aka tamarisk, Tamarix spp.), however the Shubert lab will now also be conducting research on Russian olive, the less well-known riparian invader in the American southwest. Russian olive is invading from northern states and Canadian territories where it was planted extensively for use as a wind-break in agricultural areas. It has naturalized along many western rivers, where it tolerates drought, reduced riparian disturbance and is able to regenerate in the shade of a mature forest canopy.
While saltcedar has received widespread condemnation by the scientific community, many are still conflicted about the benefits and detriments to the riparian environment associated with Russian olive. For example, in Colorado, Russian olive is listed on the State Weed List in conjunction with a mandate to remove or restore sites infested by this species. In Montana, Russian olive is still for sale at the state nursery.
Clearly, more research is needed in order to understand the impact of Russian olive invasion on native plant community assemblages and in-stream flows. In the Shubert Lab, we are exploring the following questions:

  1. Is Russian olive altering localized soil nitrogen dynamics, further deterring cottonwood germination?
  2. After Russian olive removal, what plant species are likely to regenerate? What are the observed differences in sites that are actively re-vegetated versus passively re-vegetated?
  3. Can we quantify the relationship between site characteristics such as soil texture and precipitation with potential for Russian olive invasion?

For this research, we are currently looking for Russian olive populations across the West. If you are aware of a specific where there is a current stand or where there has been Russian olive removal or restoration activity, please contact us. We are particularly interested in sites where removal and/or re-vegetation have taken place in the last fifteen years. Any assistance will be greatly appreciated, and your help acknowledged in any resulting publications.
Maggie Meehan, PhD student
University of Denver
Biological Sciences

Colorado Riparian Association