European survey finds varied ecosystem typologies support condition assessment but limit comparability

A review and partner survey of ecosystem typologies across 31 countries found that national classifications can complement European and global systems, but differences in structure, data, reporting and maintenance complicate comparisons in ecosystem condition assessments.

The study examined national, subnational, European and global typologies used by members of the SELINA consortium. Researchers distributed a structured survey in February 2023 to scientists and national-authority representatives involved in ecosystem assessments or accounting. They received 32 responses covering the 27 EU countries, the United Kingdom, Switzerland, Norway and Israel, with separate responses from Portugal and the Azores.

A parallel literature review examined European and global frameworks, while structured discussions at workshops in Madrid and Trondheim considered links between typologies, condition variables and reference levels. The survey identified 42 typologies: 24 with national scope, 14 with European or global scope and eight with subnational focus.

National systems included Germany’s biotope classifications, France’s ZNIEFF, Finland’s habitat classification, Spain’s SIOSE, Hungary’s Á-NÉR and Norway’s Nature Index. Some were hierarchical, science-driven frameworks extending from broad ecosystem categories to detailed subtypes. Others were tied to particular datasets, monitoring programmes or assessments. Sweden used sampling-based assessment rather than a continuous national map, while Spain used a list-based approach.

Respondents reported compatibility between national classifications and EUNIS and CORINE Land Cover in 13 cases each, while MAES received 10 such mentions. National systems commonly combined field observations with remote sensing, ecological inventories and, in some cases, predictive models.

Among respondents to the question about condition assessments beyond mandatory EU directive requirements, 64% reported undertaking such assessments, 14% said they had not and 21% were uncertain. Woodland and forest ecosystems were mentioned most often, with 25 mentions, followed by croplands with 15, grasslands with 14, freshwater ecosystems with 14, and urban ecosystems with 11. These counts referred to ecosystem types rather than individual typologies, and respondents could list multiple types.

Comprehensive surveys or statistically robust estimates were reported in 61% of method responses; 26% involved extrapolation from limited data, 10% relied on expert opinion and 3% indicated that assessment was not possible because data were insufficient. The survey showed strong reliance on national sources, which accounted for 89% of cited sources, with international sources contributing 21%.

The authors concluded that condition-enabled typologies should have exhaustive and mutually exclusive classes, represent dominant socioecological processes and be ecologically homogeneous enough to support shared condition variables and meaningful reference levels. They should combine theoretical definitions with reproducible operational rules, use a characteristic spatial scale aligned with the relevant processes, and avoid treating temporary states such as recently harvested or burned areas as separate ecosystem types. Hierarchies can allow different reference levels for subtypes while retaining consistent condition variables within a higher-level class.

The review identified persistent barriers, including irregular national reporting, differences in data and classification methods, and limited institutional maintenance for project-specific typologies. Its scope was limited by reliance on SELINA partners and their reported systems rather than a census of every national typology. The authors recommend standardized but adaptable frameworks, carefully validated crosswalks based on ecological meaning rather than label similarity, and more regular reporting to support comparable ecosystem extent and condition accounts.

Subject of Research: Compatibility of national and international ecosystem typologies for ecosystem condition assessment

Article Title: Integrating national and international ecosystem typologies for condition assessments: Principles for typology design and policy alignment

Article References: Rendón, P., Watson, M., Czúcz, B., Ruf, K., Kleeschulte, S., & Santos-Martín, F. (2025). Integrating national and international ecosystem typologies for condition assessments: Principles for typology design and policy alignment. One Ecosystem, 10, Article e163068. https://doi.org/10.3897/oneeco.10.e163068

Image Credits: AI Generated

DOI: 10.3897/oneeco.10.e163068

Keywords: ecosystem typologies, ecosystem condition, national classifications, European frameworks, crosswalks, SEEA ecosystem accounting, EUNIS, CORINE Land Cover, MAES, biodiversity monitoring, Integrating, national