Effects of goat grazing and mowing on seed density and seed mass of <em>Lespedeza cuneata</em>

Abstract

Sericea Lespedeza (Lespedeza cuneata), a non-native perennial legume, is a particularly problematic invasive species for tallgrass prairie restoration, reducing plant and animal diversity while proving difficult to eradicate by traditional management tools. While reduction of aboveground growth is the goal of most eradication programs, the seed bank of L. cuneata, which could contribute to the germination of new plants, should also be taken into account when considering the success of any eradication efforts. This study, conducted at the Conard Environmental Research Area in Kellogg, Iowa, examined the effectivenessof seasonal mowing and consecutive summer goat grazing rotations in reducing the density and mass of L. cuneata seeds. We found a significant reduction in the density and mass of L. cuneata seeds between the mow treatment and all other treatments, while the goat rotations plots were not significantly different from each other or from the control plots in either seed density or seed mass. This data suggests that the mow treatment has been the most effective in reducing the density and mass of L. cuneata seeds in the soil. It also appears that even if goat grazing has been effective in reducing aboveground biomass of L. cuneata, it might take several more years before the seed bank of L. cuneata is significantly reduced.