Assessing the Economic, Environmental, and Societal Losses from Invasive Plants on Rangeland and Wildlands1

Abstract A literature review was conducted to summarize information on environmental, economic, and societal losses caused by 16 key invasive plants on rangeland and wildlands in the United States. Results of the literature review indicated that scope of published information ranged from narrow to comprehensive. Extensive quantitative information is published about environmental impacts caused by leafy spurge, downy brome, saltcedar, purple loosestrife, and several knapweeds or starthistle. For other species, quantitative information was limited and references to impacts were mainly anecdotal or observational. The economic impacts of most species were poorly documented. Comprehensive economic analyses conducted on either a state or regional basis were published about leafy spurge, saltcedar, and the knapweeds. Agricultural costs including loss of grazing value were quantified for several additional species, but environmental and societal costs were not included in the analyses. Additional research is needed to quantify economic and environmental losses of invasive nonnative plants on rangeland and wildland sites. Nomenclature: Downy brome, Bromus tectorum L. #3 BROTE; leafy spurge, Euphorbia esula L. # EPHES; purple loosestrife, Lythrum salicaria L. # LYTSA; saltcedar or tamarisk, Tamarix spp., # TAASS; yellow starthistle, Centaurea solstitialis L. # CENSO. Additional index words: Exotic plants, invasive plant impacts, noxious weed impacts.