Reuben Keller
Friday, October 17, 2008 - 8:30-9:00
Invasive plants are a leading cause of global environmental change. Recognizing this, land managers allocate significant resources to reduce the impacts and spread of harmful non-native species. Although these control efforts produce large conservation benefits they are often costly. It is estimated that over $22 billion is spent annually on the control of terrestrial and aquatic invasive plants in the United States. Expenses at both the local and national levels are likely to increase in the future for two reasons. First, most invaders are well established and spreading. These species are unlikely to be eradicated, and will require additional control as they reach new regions. Second, the main vector of new invasive species, the nursery plants trade, continues to introduce new species with little assessment of the risks posed. Thus, reducing the future economic impacts of invasive plants will depend on the degree to which the spread of known invaders and the introduction of new invaders can be prevented. We are have combined economic and ecological models to determine methods for reducing the future costs of invasive species, and will present results from two studies. First, we have investigated the costs of different management approaches to the control of Eurasian watermilfoil. Second, we have shown that preventing the arrival of new invaders using ecological risk assessment can lead to large economic benefits in the long run. Together, these studies show that although the economic costs of invasive species are large, strategic control can reduce the costs and produce environmental benefits.
Keywords: INVASIVE PLANTS, ECONOMICS, PREVENTION, RISK ASSESSMENT, ECOLOGICAL PREDICTION.