Sagebrush research

Role of the soil microbial community in sagebrush (Artemisia tridentata) and squirreltail (Elymus elymoides) seedling establishment in cheatgrass-invaded habitats

Funding:  Department of Defense SERDP

Principal Investigators:  Paul Dijkstra (PI), Egbert Schwartz, Catherine Gehring, Bruce Hungate (Co-PIs),

Key personnel/students:  Christine Mitchell,Lluvia Flores-Rentería (post-doc), Adair Patterson, Courtney Callaway

Synopsis:  Cheatgrass invasion and consequent increases in fire frequency and ecosystem deterioration in sagebrush habitat make it difficult for native grass and shrub species to re-establish. One explanation for the poor seedling establishment is that in the long-term absence of suitable host plants, the abundance of beneficial rhizosphere microbes declines strongly. These microbes include mycorrhizal fungi, but also many bacterial species. We propose that when these microbes are reintroduced in cheatgrass-invaded areas, seedling establishment will be improved. We are testing whether invasion of cheatgrass into pristine sagebrush ecosystems changes the rhizosphere microbial community composition and function of sagebrush (Artemisia tridentata) and squirreltail (Elymus elymoides) consistently across broad geographical distances. We are also examining whether inoculation with rhizosphere soil from pristine sagebrush habitat restores the rhizosphere community composition and function of sagebrush and squirreltail seedlings in cheatgrass-invaded areas and improves their establishment, growth, survival.

This project is new and no publications have been produced yet.  However, the paper below helped us develop ideas regarding the interactions among arbuscular mycorrhizal fungi, fire, cheatgrass and squirreltail.

Owen, S.M., C.H. Sieg, N.C. Johnson, and C.A. Gehring. 2013.  Exotic cheatgrass and loss of soil biota decrease the performance of a native grass. BIOLOGICAL INVASIONS 15:2503-2517.