Setting reference levels and limits for good ecological condition in terrestrial ecosystems – Insights from a case study based on the IBECA approach

•We present five conceptual approaches for setting indicator reference values.•We present four conceptual approaches for setting indicator limit values.•The choice of approach depends on data availability, coverage and type.•We discuss practical considerations and possible solutions to setting these values.•We aim to contribute to development and practical use of this type of value setting.