Athens, Ga. Weedy plants, many introduced to the U.S. for sale through plant nurseries, are responsible for extensive environmental damage and economic costs. Although legislation restricts the introduction of certain species, the procedures used to select species for inclusion on the restricted list are haphazard and out of date.
To meet the need for more systematic weed risk analysis, researchers at the University of Georgia Odum School of Ecology and the University of California, Davis have developed a "cost-sensitive" model to determine when importing a given plant is worth the risk. Their work was published in the May edition of the journal Ecosphere.
Although the problems caused by invasive plants are well known, Odum School postdoctoral associate J.P. Schmidt, the lead scientist on the study, said the U.S. has historically placed very few restrictions on the import of plants.
According to UC Davis economist and study co-author Mike Springborn, "our approach represents a shift from the current practice of scrambling to address invasives only after they are already established. In this paper, we develop tools for making informed decisions ahead of time about which plants have an acceptable level of risk given their anticipated benefits. We now have the combined biological and economic tools to take an informed look before we leap with trade in new species."
The model uses statistical procedures to assess how likely a plant is to become a weed. To do this, it compares the estimated probability with the average costs of a new weed and the expected losses from foregone sales of non-weed species that are presumably safe. Using the model as a screening tool, the researchers say, would provide a net economic benefit of at least $80,000 to $140,000 per species assessed, which could translate into tens of millions of dollars in total.
Had the proposed screening system been in place historically, they calculat
|Contact: J.P. Schmidt|
University of Georgia