The valuation of ecosystem services (ES) employs a range of methods. Based on a literature review and selected empirical examples, we consider major opportunities and challenges in ecosystem services valuation. We analyse when different valuation methods are appropriate and most useful. We demonstrate that mechanisms to capture benefits and costs are needed; and that the use of valuation should be incorporated more widely in decision-making. However, we argue that ecosystems are complex systems: neither the ecosystems or the services that they provide are a sum, but are an interrelated system of components. If a component vanishes the whole system may collapse. Therefore, critical natural capital management, in particular, cannot rely on monetary values; whilst the maintanance of the whole system should be considered. Monetary valuation of biodiversity and landscapes is also problematic because of their uniqueness and distinctiveness, a shortage of robust primary valuations, and numerous complexities and uncertainties. We conclude that mixed method and deliberative discourse techniques, as well as proper integration of research tools, should be more widely applied to help decision-makers and the public to understand and assess changes in ES. The approaches developed and tested by us, as presented in this paper, can provide more complete, comprehensive and impartial insights into a range of benefits that humans derive from ecosystems.
