Cheatgrass Seed Banks
and Pathogen Abundance

Direct quantification of field seed bank samples enables us to examine the relationship between seed abundance and pathogen abundance in different habitats.


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What it's about

What we found out

What we did

We have used seed bank surveys at more than 80 sites to characterize the density of viable cheatgrass carryover seeds and pathogen-killed seeds, and have also carried out intensive multiple-year studies at several sites. These samples have also yielded the isolates for genetic characterization and virulence testing.

Our pathogen is more abundant at dry sites, where fall precipitation is inadequate to trigger full germination, than at sites with higher precipitation, where most seeds germinate rapidly in fall. Remaining secondarily dormant seeds are the primary prey of the pathogen. Higher potential seed carryover means higher disease levels, so that viable seed carryover is generally low at both dry and wet sites.

Principal Investigator: Dr. Susan Meyer
Co-PI's: Dr. Julie Beckstead, Dr. Phil Allen
Technical Support: Stephanie Carlson, Duane Smith, Bettina Schultz
Students:  Owen Baughman, Heather Finch, Katie Merrill, Thom Stewart

Meyer, S.E.; Quinney, D.; Nelson, D.L.; Weaver, J. 2007. Impact of the pathogen Pyrenophora semeniperda on Bromus tectorum seedbank dynamics in North American cold deserts. Weed Research 47:54-62.

Katie taking seed bank sample

Katie taking a seed bank sample