Invasive Alien Species in Switzerland: Awareness and Preferences of Experts and the Public.

Invasive alien species (IAS) can cause ecological and economic damages. To reduce or prevent these damages different management and prevention strategies aim to impede new establishments or a further spreading of IAS. However, for these measures to be successful, public knowledge of risks and threats of IAS as well as public support for eradication measures are important prerequisites. We conducted a survey to examine (i) public and experts' awareness and knowledge of IAS, (ii) their preferences for six invasive plant species and (iii) their preferences for and trade-offs among management alternatives in Switzerland. In addition, a choice experiment was applied to analyse preferences concerning the intensity, priority and costs of interventions. Both, the Swiss public and the experts have a preference for intervening against invasive alien species. However, the public and the experts differ in their priorities of combatting particular species, resulting in a different ranking of intervention necessities. Further, differences were found in the willingness to pay for interventions between the German-, French- and Italian-speaking parts of Switzerland. The results suggest that a higher problem awareness increases the willingness to pay for countermeasures. We conclude that education programs or information campaigns are promising instruments to raise public awareness and to avoid conflicts concerning the management of invasive alien species.