Exotic and Invasive Woody Plant Species in Iowa

Seventy species and hybrids of exotic woody trees, shrubs, and vines have naturalized in Iowa. Nearly half of these species (31) have become invasive pests in parts of the state or have potential do so. Most of the seriously invasive species are spread by bird ingestion of whole fruits. Widespread dispersal by birds hinders eradication efforts and should be considered a trait indicative of potential invasiveness. The economic and ecological values of Iowa forests are seriously compromised by exotic invasive woody species, especially where forests recovering from cropland and pasture are dominated by exotic species. Thus, a simple measure of acres under forest cover is a misleading indicator of the health of Iowa\u27s forest resource