The U.S. government defines invasive species as "an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health." Invasive Species in the Pacific Northwest describes these species, how they got here, and the effects of their invasions on the region's environment. Each of 108 invasive species of fish, plants, invertebrates, mammals, and birds -- including earthworms, domestic cats and pigs, blackberries, European fruit flies, Japanese eelgrass, Mediterranean mussels, rats, and terrestrial mollusks -- is described in a 2-page spread that includes a full-color photograph of the species, a map showing the species' presence in the region, plus: -- Impact on communities and native species -- Control methods and management -- Life histories and species overview -- History of invasiveness Included are suggestions to help reduce the spread of invasive species; habitat preferences of Pacific Northwest invasive species; the World Conservation Union (ICUN) list of the world's 100 most invasive alien species; and a questionnaire designed to evaluate ecological impact and invasive potential. Invasive species have been recognized as an environmental issue since Charles Darwin's voyage on the H.M.S. Beagle. Editors P. D. Boersma, S. E. Reichard, and A. N. Van Buren explore the intentional and accidental introductions of invasive species. Whether these species were deliberately brought to the Northwest for agricultural, horticultural, aquacultural, or hunting and fishing purposes, or accidentally introduced as stowaways and contaminants, knowledge about them is integral to the protection of our environment.

During September 19-20, 2006, a conference was held at the University of Washington Botanic Gardens, Seattle, WA, with the title S2Meeting the challenge: invasive plants in Pacific Northwest Ecosystems. S3 The mission of the conference was to create strategies and partnerships to understand and manage invasions of non-native plants in the Pacific Northwest. The audience included over 180 professionals, students, and citizens from public and private organizations responsible for monitoring, studying, or managing non-native invasive plants. This proceedings includes twenty-seven papers based on oral presentations at the conference plus a synthesis paper that summarizes workshop themes, discussions, and related information. Topics include early detection and rapid response; control techniques, biology, and impacts; management approaches; distribution and mapping of invasive plants; and partnerships, education, and outreach.

Nonnative plants affect the composition and function of natural and managed ecosystems and have large economic effects through lost or degraded land use and eradication costs. In spite of their importance, very little comprehensive information on the abundance, distribution, and impact of nonnative invasive plants is available. The objective of this study was to prioritize a list of nonnative invasive plants affecting forest lands in the Pacific coastal states of California, Oregon, and Washington, and provide enough detail in nontechnical language and photos of different stages of plant development to allow reliable identification in the field. Information was synthesized from a variety of national, regional, and state lists, assessments, and botanical guides. The final list was designed to capture species believed to be most prevalent or problematic and to be used for strategic forest inventories like the Forest Inventory and Analysis Program. Identification of the several hundred nonnative invasive species present in the region requires substantial taxonomic experience; a prioritized short list of species with practical identification tips can be a good place for novice botanists and large-scale monitoring efforts to start.