Phytosociological relationships in European Union policy-related habitat classifications

Abstract

Over the past half century, nature protection in the European Union has been increasingly controlled by commitments to policy and legislative frames, notably the Habitats Directive, originating from the European Union and adopted by an enlarging constituency of member states. Habitat (or biotope) classifications developed in association with these policies, first the Palaearctic habitat classification and CORINE, then the EUNIS habitat classification, have provided typologies with definitions of habitat types intended to aid their recognition, mapping, protection and monitoring. Phytosociological expertise and classifications of formally defined plant communities or syntaxa have played a part in the development of these typologies and in interpretation of the Habitats Directive from the start, though this involvement has been complex and sometimes unclear. This paper catalogues this history and shows how the development of increasingly robust definitions of EUNIS habitat types, an overarching European framework of phytosociological syntaxa and very substantial point-source data (releves) are converging to aid the interpretation and delivery of environmental policy. In particular, crosswalks between EUNIS habitat types and syntaxa, lists of constant, differential and dominant species, standardised habitat descriptions as well as distribution, predictive and indicative maps are now becoming available. The European Red List of Habitats, also based on the EUNIS typology, provides images and other complementary information on distribution, pressures and threats and a Red List assessment. A comprehensive factsheet with complementary fuller environmental parameterisation for each EUNIS habitat type remains a realistic goal.