Bioeconomic forecasting of invasive species by ecological syndrome

Invasive non-native species cause enormous economic damage. Although there is both regulative and legislative precedent for policies restricting introduction of potentially invasive species, lack of a unified theory of invasions-particularly with respect to plants-has impeded efforts to implement screening despite empirical patterns suggesting the existence of invasion syndromes. Motivated by recent advances in the comparative biology of invasive species, we sought to develop a cost-sensitive model that would associate groups of species according to biological traits and assign them to risk categories based on their invasion potential. Focusing on invasive plants in the US, which are estimated to generate costs of $US34.7 billion/year, we then combined this scheme with estimates of the per species expected economic losses associated with forgoing trade and with benchmark values for the economic costs associated with plant pests to obtain a decision tool that would maximize economic benefits. If used for screening, this tool is estimated to yield expected net benefits of $80,000-$ 140,000 per species assessed under very conservative estimates of losses due to invasion.