While ecosystems have concrete benefits for human society, these benefits are typically overlooked in decision-making. This is problematic because ecosystems – and thus the benefits that... Show moreWhile ecosystems have concrete benefits for human society, these benefits are typically overlooked in decision-making. This is problematic because ecosystems – and thus the benefits that ecosystems provide – are under increasing pressure from human actions. The ecosystem services concept aims to better reflect the benefits of ecosystems for human wellbeing. As a tool to quantify ecosystem services, their value is often estimated in monetary terms. This thesis investigates whether this approach is valid in ecological terms: do monetary value estimates adequately reflect the ecological status of the ecosystem? Two sets of water-related services in two different types of regions have been investigated: water quantity-related services in global drylands (chapters 2 and 3) and water quality-related services in the Scheldt river basin (chapters 4 and 5). The results show that the selected methodological approach has a dominant impact on value estimates for water-related services, while the ecological status of the ecosystem is of minor importance. This finding casts doubts upon the validity of monetary valuation as a means to take the ecological status of ecosystems into account in public decision-making. Future research should explore how the ecosystem’s ecological status can be better integrated in the valuation of ecosystem services. Show less
