Tuesday, August 7, 2007
Exhibit Halls 1 and 2, San Jose McEnery Convention Center
Microstegium vimineum (Poaceae), Japanese stiltgrass, is an invasive C4 grass adapted to living in shaded environments. Previous studies have suggested that bare soil microenvironments might be important to the establishment of new M. vimineum populations. This observation combined with the proclivity of M. vimineum for commonly disturbed areas suggests a tight relationship between disturbance regimes and the establishment of M. vimineum populations. The aim of this research was to experimentally evaluate this relationship by manipulating vegetation, litter, and soil conditions along forest road edges and then examine dispersal and recruitment. Six roadside study sites, with established populations of M. vimineum, were selected for study from the Wayne National Forest in southeastern Ohio. Within each site (statistical block), we established four experimental treatments in a 2 × 2 design by keeping/removing understory vegetation and disturbing/not-disturbing understory litter/soil (fixed effects). We then monitored each treatment for M. vimineum recruitment, cover, species richness, as well as the movement of the edge community into the forest understory. After one year of observation, our results indicate that, disturbance of the litter layer was the most significant effect influencing the germination and establishment of M. vimineum. However, none of the treatments significantly affected the rate of migration of the road edge community into the forest understory, or species richness. Additional years of observation may provide more insight into the rate of dispersal and migration at forest road edges.
