Indicators for biodiversity and ecosystem services: towards an improved framework for ecosystems assessment

Ecosystem assessment and monitoring requires the development and application of suitable indicators, i.e. they need to be (i) reliable and capable of simplifying complex relationships, (ii) quantifiable and transparent in order to enable an easy communication, and (iii) fit for the purpose of indication. These requirements are scarcely fulfilled in current ecosystem assessment and monitoring efforts to address the requirements of international biodiversity conventions. Here we present and test a set of seven criteria towards an improved framework for ecosystems indication with particular emphasis on the indication of biodiversity and ecosystem services: purpose of indication, indicator type according to the EEA's Driver-Pressure-State-Impact-Response scheme, direct/indirect linkages to biodiversity and ecosystem services, spatial scale and scalability across scales, applicability of benchmarks/reference values, availability of data and protocols, and applicability of remote sensing. The criteria are tested using 24 indicators of ecosystem assessment and monitoring at the global, continental and regional scale. Based on the general trends revealed by our evaluation, we present recommendations to streamline and improve ecosystem indication with respect to international biodiversity conventions. The implementation of our recommendations does require concerted international effort, comparable, for instance, to the implementation of the Water Framework Directive in Europe.