When good forests look bad: new research highlights distorting effects in EU conservation reporting

A new peer-reviewed study by European Forest Institute (EFI) researchers Harald Mauser and Magda Bou Dagher Kharrat, together with Bart Muys from KU Leuven, examines how current EU conservation status assessment methods may distort the reported condition of forest habitats. 

The article, “When good forests look bad: Methodological biases in EU conservation status reporting”, published in Biological Conservation, focuses on reporting under Article 17 of the EU Habitats Directive.  It finds that existing rules, thresholds, and aggregation approaches can significantly limit the assessment’s sensitivity to both positive and negative change in forest conservation status.

As a result, a striking discrepancy emerges. While around 50% of assessed forest habitat area are categorised to be in good ecological condition at Member State level, only about 14% of forest habitats were reported with a “Good” conservation status at EU level.

The study shows that this gap is largely due to methodological choices rather than being founded in actual ecological reality. These include the overly stringent application of the flexible area threshold for assessing habitat structure and functions, the “one-out-all-out” principle used to combine assessment parameters, and the aggregation of national results into EU-wide indicators. Together with the limited standardisation of data sources and assessment approaches between Member States, these factors reduce comparability and make it harder to track real progress in forest restoration.

Importantly, highlighting these methodological limitations does not suggest that European forests are in good condition. Instead, the authors caution against equating conservation status reporting with the overall condition of Europe’s forests, including their diversity, vitality, and ecosystem service provision. 

“Forest habitats are slow evolving systems”, observes lead author Harald Mauser, “Monitoring them requires a simple, transparent, and stable approach, which also helps keep stakeholders motivated to implement effective and efficient measures to develop habitats towards good condition.”

The research aims to contribute constructively to ongoing discussions among EU institutions, Member States and scientific experts. Its findings can inform improvements to the assessment approach for the upcoming reporting period and to support the implementation of the EU Nature Restoration Law.  In particular, complementing current habitat-count-based indicators with clearer area-based information and communicating methodological limitations more transparently could support better-informed decision-making and more effective restoration planning. 

The full open-access article is available for readers interested in the detailed analysis and proposed pathways to strengthen Europe’s forest conservation assessments.

Mauser, H., Bou Dagher Kharrat, M., Muys, B. 2026. When good forests look bad: Methodological biases in EU conservation status reporting, Biological Conservation, Vol 313, https://doi.org/10.1016/j.biocon.2025.111610.

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