Invasive weedy plants are an extremely serious problem throughout the United States and particularly on rangelands in the West. It has been estimated that another 4,600 acres of public natural areas are lost to invasive exotic plant species every day. As exotic plants spread rapidly across North America and dominate new areas, they displace desirable plants that provide valuable forage for livestock and wildlife, eliminating critical habitats and affect other natural resources (including water) that are important for threatened and endangered species as well as agricultural production. In cases like salt cedar, where soil salinity is greatly increased, they may make habitats unsuitable for other species to regrow in the future. In several western states, invasive and exotic plant species such as yellowstar thistle, salt cedar, perennial pepperweed, several knapweed species, and leafy spurge have made some productive agricultural lands nearly worthless. This problem, however, is not restricted to the terrestrial environment. Thousands of aquatic and semi-aquatic habitats are also highly infested with invasive exotic weeds such as purple loosestrife, Cape ivy, Eurasian watermilfoil, water hyacinth, and hydrilla. Recent reports thoroughly document the impact of weeds and actions needed for their long-term management. One estimate indicates that non-indigenous weeds cost the U. S. between $3.6 and $5.4 billion annually.
The mission of this unit is to provide national leadership in the development of novel methods for managing exotic and invasive weeds of rangelands and aquatic sites. Technology developed through this program provides the pest control methods used to devise effective and sustainable Integrated Pest Management (IPM) programs that support agricultural production and integrity of natural ecosystems in diverse situations throughout the country. The underlying philosophy of this program is to develop and help implement sustainable approaches to managing pests through a combination of biological, cultural, mechanical, and chemical tactics that reduce pest populations to acceptable levels while minimizing economic loss, impacts on human health, and environmental risk.