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.
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
trigger full germination, than at sites with higher precipitation, where
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.
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.