Socio-economic impact and assessment of biological invasions

Biological invasions have been object of ecological research for years.As one objective, natural scientists investigate the effects of invasive species on ecosystems and their functioning (Levine et al. 2003). However, impacts on ecosystems are also of relevance for society. Changes in ecosystems affect humans insofar as ecosystems provide goods and services, such as fresh water, food and fibres or recreation, which might be altered due to invasive species. Therefore, impacts of biological invasions should be an object of socio-economic interest, which is also demanded by the Convention on Biological Diversity (2002).
This chapter aims at providing elements for the analysis of impacts of invasive species from the socio-economic point of view. Such an analysis is politically relevant, since impacts are the focal point of every decision to establish an appropriate management regime. For an all-encompassing analysis, an integrative framework is needed to structure the information on impacts. For that purpose, the concept of ecosystem services (Chap. 13) is introduced (Sect. 19.2). Alternative decisions on the appropriate management of invasive species face trade-offs between outcomes and impacts. For handling such trade-offs, evaluation is needed.As discussed in Sect. 19.3, perception presents the prerequisite of an explicit evaluation. Finally, different evaluation methods are introduced so as to value the information about impacts during the decision-making process.