From expert judgement to supervised classification: A new approach to assess ecological status in lowland streams

► We find that a paradigm exists among experts that can guide the development of WFD assessment systems for aquatic plants. ► The expert interpretation of ecological status can be transferred into a supervised classification model. ► The model can be used to classify plant assemblages from new stream sites into ecological status classes. ► This approach may be particularly useful in water body types where a reference network cannot be established.