DOT Project Number:  90-00-LRTF-304

Fiscal Year:  2003

Award:  $12,257.00

Principal Investigator:  Dr. Brian Wilsey, Department of Ecology, Evolution and Organismal Biology, Iowa State University, bwilsey@iastate.edu

Summary Report:

Germination rates, seedling establishment and second year prairie biomass were sampled in experimental restoration plots in the Iowa Loess Hills. Plots had a single C4 grass species seeded as the dominant (replicated with 5 species), either from locally collected seed or from cultivars, as well as a mix of 26 forb and C3 grass species. Cultivar seed had higher germination in 4 out of 5 species in greenhouse germination trials, but seedling establishment in the field differed less consistently between cultivar and locally collected seed. Early prairie establishment (peak biomass) declined as the biomass of weeds (exotic species not in the prairie mix) increased, was unrelated to soil moisture, and was not different among dominant grass treatments. Whether grass treatments differentially affect prairie species diversity will be tested with further monitoring. However, early prairie establishment responses suggest that weeds have highly negative effects on mixed grass prairie establishment and need to be treated to speed-up the restoration process or to prevent the project from failing.