The introduction of potentially invasive alien plant species for horticultural purposes in North America: Assessing stakeholder perspectives and preferences

Invasive alien plant species are known to cause significant economic and ecological losses. Nonetheless, potentially invasive plant species are often deliberately introduced and sold for ornamental horticulture. Although links between the nursery trade and the invasive alien plant problem are recognized, existing policies largely ignore the problem's horticultural dimension. Therefore, novel policies are needed to reduce invasion risks stemming from deliberate introductions. However, many stakeholders are affected by the problem, including those benefiting from horticultural sales and those negatively affected by invasions, and their policy preferences are not clearly documented. I describe current regulations, present viable alternatives and, through the analysis of survey data, explore stakeholder preferences for a variety of policy options. While policies rooted in white listing are most popular, policy preference varies both between and within role-based stakeholder groups. Although most respondents preferred a mandatory approach, a small subset of the sample favoured voluntary measures.;Keywords: Invasive alien plant species; ornamental horticulture; policies; black listing; screening; economic instruments; stakeholder preferences; North America.