Assessing stakeholder perspectives on invasive plants to inform risk analysis

Authors: KAPLER, EMILY - Iowa State University; THOMPSON, JANETTE - Iowa State University; Widrlechner, Mark

Submitted to: Invasive Plant Science and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2012
Publication Date: 7/14/2012
Citation: Kapler, E.J., Thompson, J.R., Widrlechner, M.P. 2012. Assessing stakeholder perspectives on invasive plants to inform risk analysis. Journal of Invasive Plant Science and Management. 5(2):194-208.

Interpretive Summary: Land managers spend long hours containing invasive plants encroaching on natural areas. Given the extensive resources devoted to their control, pre-empting introduction of new potential invaders would be beneficial. Risk-assessment models can be used to screen new plants for invasiveness, but their implementation is challenging. Since most new plants are deliberately introduced, stakeholders’ needs must be accounted for if pre-emptive management efforts are to be successful. We surveyed four stakeholder groups in Iowa (conservation professionals, master gardeners, professional horticulturists, and woodland landowners), who are key voices in decision-making for invasive plants, about their perspectives on general management approaches and risk-assessment models. We also examined whether nature relatedness (a person’s sense of connection to the natural world) helps shape these perspectives. We found these stakeholder groups had relatively minor differences of opinion. They agreed that invasive plants were a problem that we have a responsibility to manage and were open to the idea of passing state laws or mandates to achieve that goal. This was true even of professional horticulturists and master gardeners, who would potentially incur more costs than benefits from such regulations. Stakeholders also displayed consistently high levels of nature relatedness, and concerns they have about invasive plants may be influenced by their identification with nature. Overall, our findings suggest that risk analysis to limit introduction of potentially invasive plants is likely to be acceptable in Iowa. When evaluating specific models, stakeholders believe choosing models with a low chance of introducing potentially invasive plants is more important than choosing models with a low chance of excluding plants unlikely to become invasive. Current risk-assessment models, which emphasize prevention of invasive-plant introduction over preventing introduction of benign plants, align well with stakeholder preferences. These findings should aid both modelers and regulators in the crafting and implementation of appropriate risk-assessment strategies.

Technical Abstract: Conservation and land management decisions are often based primarily on natural science, but could be more successful if human influences were effectively integrated into decision-making. This is especially true for efforts to manage invasive plants, whose arrival is usually the product of deliberate human introduction. Risk-assessment models that predict the probability that a non-native plant will naturalize or invade are useful tools for managing invasive plants. However, decisions based on such models could affect stakeholders differently. Careful assessment of risk-analysis methodologies should consider the importance of stakeholder participation. We surveyed the perceptions of four stakeholder groups (conservation professionals, master gardeners, professional horticulturists, and woodland landowners) in Iowa about invasive plants, general management approaches, and risk-assessment models. We also examined whether or not a stakeholder's nature relatedness plays a role in shaping his or her responses. Stakeholder perceptions varied less than expected across all four groups. Eighty-seven percent of respondents agreed invasive plants are a problem, and 88.4% agreed that we have a responsibility to manage them to protect natural areas. Support for the use of risk-assessment models is also high, with 78.7% of respondents agreeing their use has potential to prevent plant invasions. Nature relatedness scores for all groups were correlated with respondent perspectives on invasive plants. Respondents believe biologically significant error rates (errors that may introduce a new invasive plant) should not exceed 5% to 10%. Respondents were more tolerant of horticulturally limiting errors (errors that restrict sale/use of a plant that would not have become invasive), reporting rates of 10% to 20% as acceptable. Researchers developing risk-assessment models may wish to aim for error rates within these bounds. General agreement among these stakeholder groups suggests potential support for future risk management efforts related to invasive plants.