Nonnative Species

Kudzu on trees

Chuck Rafkind

Invasive exotic flora is a major threat to the natural integrity, agricultural and economic well being of the USA and nations worldwide. Control of invasive exotic species is a major initiative of Federal land management agencies and the object of a Presidential Executive Order to begin control of invasive exotic species. In 1999 Colonial National Historical Park initiated a two-year inventory of invasive flora. The study identified and mapped invasive flora within park boundaries and prioritize them for management. Once mapped, species were prioritized for management action based on their level of threat and feasibility of control. The two years of fieldwork included inventory of the forest, fields, wetland of the park. In the forested areas, 24 invasive exotic species were found. Along roadsides, 39 invasive exotic species were found, and in fields, 38 invasive species were found. Species causing the greatest impact, based on the parkwide acreage they cover, are Microstegium, Japanese honeysuckle, Bermuda grass, tall fescue, Chinese privet, orchard grass and Chinese lespedeza. Complete control of these species throughout the park will be difficult and costly. Therefore, specific populations or areas of the park are considered for management of these species. Highly invasive species with low coverage throughout the park, such as the tree of heaven, princess tree, privet, Asian bamboo, kudzu, Oriental bittersweet Japanese knotweed, Phragmites, English ivy, non-native wisteria, Japanese honeysuckle, and mimosa, are the top priorities for control. Multi-park vegetation management teams serving Virginia’s National Park units and the National Capital Regional parks were established and over the past three years have controlled over 55 acres at Colonial including kudzu, tree of heaven, princess tree, privet, Oriental bittersweet, Japanese honeysuckle, English ivy, multiflora rose, Japanese barberry, bamboo and Phragmites (common reed).