Incorporating insurance value into ecosystem services assessments: Mitigation of ecosystem users' welfare uncertainty through biological control

Ecosystems and underlying biodiversity frequently ensure sustained welfare by reducing the risk associated with detrimental biological agents. This attribute is commonly termed biological control, but its valuation is usually underrepresented in the ecosystem services literature. In our study, a unique valuation method is applied, based on the natural insurance value of biological control and its contribution to expected welfare, evaluating its importance in mitigating ecosystem users' welfare loss under uncertain conditions. The study tests the feasibility of a conceptual valuation model using the Mediterranean Sea as a case study by assessing the properties of indigenous species to mitigate the impact of invasive species. The results show that varying the levels of indigenous ecosystem components governs the probability of potential welfare loss and its associated value to ecosystem users. While an increase in indigenous biomass levels results in an increase in the total value of biological control, positive values of insurance are achieved only at a certain biomass level, from which the welfare uncertainty of ecosystem users is gradually reduced. Below such levels, the ecosystem component responsible for mitigating risk does not supply any insurance values, as it increases the certainty of low welfare for ecosystem users.