EUNIS Habitat Classification: Expert system, characteristic species combinations and distribution maps of European habitats
Authors: Chytrý Milan , Tichý Lubomír , Hennekens Stephan M. , Knollová Ilona , Janssen John A. M. , Rodwell John S. , Peterka Tomáš , Marcenò Corrado , Landucci Flavia , Danihelka Jiří , Hájek Michal , Dengler Jürgen , Novák Pavel , Zukal Dominik , Jiménez‐Alfaro Borja , Mucina Ladislav , Abdulhak Sylvain , Aćić Svetlana , Agrillo Emiliano , Attorre Fabio , Bergmeier Erwin , Biurrun Idoia , Boch Steffen , Bölöni János , Bonari Gianmaria , Braslavskaya Tatiana , Bruelheide Helge , Campos Juan Antonio , Čarni Andraž , Casella Laura , Ćuk Mirjana , Ćušterevska Renata , De Bie Els , Delbosc Pauline , Demina Olga , Didukh Yakiv , Dítě Daniel , Dziuba Tetiana , Ewald Jörg , Gavilán Rosario G. , Gégout Jean‐Claude , Giusso del Galdo Gian Pietro , Golub Valentin , Goncharova Nadezhda , Goral Friedemann , Graf Ulrich , Indreica Adrian , Isermann Maike , Jandt Ute , Jansen Florian , Jansen Jan , Jašková Anni , Jiroušek Martin , Kącki Zygmunt , Kalníková Veronika , Kavgacı Ali , Khanina Larisa , Yu. Korolyuk Andrey , Kozhevnikova Mariya , Kuzemko Anna , Küzmič Filip , Kuznetsov Oleg L. , Laiviņš Māris , Lavrinenko Igor , Lavrinenko Olga , Lebedeva Maria , Lososová Zdeňka , Lysenko Tatiana , Maciejewski Lise , Mardari Constantin , Marinšek Aleksander , Napreenko Maxim G. , Onyshchenko Viktor , Pérez‐Haase Aaron , Pielech Remigiusz , Prokhorov Vadim , Rašomavičius Valerijus , Rodríguez Rojo Maria Pilar , Rūsiņa Solvita , Schrautzer Joachim , Šibík Jozef , Šilc Urban , Škvorc Željko , Smagin Viktor A. , Stančić Zvjezdana , Stanisci Angela , Tikhonova Elena , Tonteri Tiina , Uogintas Domas , Valachovič Milan , Vassilev Kiril , Vynokurov Denys , Willner Wolfgang , Yamalov Sergey , Evans Douglas , Palitzsch Lund Mette , Spyropoulou Rania , Tryfon Eleni , Schaminée Joop H. J. 
Published: July 2020

AbstractAimThe EUNIS Habitat Classification is a widely used reference framework for European habitat types (habitats), but it lacks formal definitions of individual habitats that would enable their unequivocal identification. Our goal was to develop a tool for assigning vegetation‐plot records to the habitats of the EUNIS system, use it to classify a European vegetation‐plot database, and compile statistically‐derived characteristic species combinations and distribution maps for these habitats.LocationEurope.MethodsWe developed the classification expert system EUNIS‐ESy, which contains definitions of individual EUNIS habitats based on their species composition and geographic location. Each habitat was formally defined as a formula in a computer language combining algebraic and set‐theoretic concepts with formal logical operators. We applied this expert system to classify 1,261,373 vegetation plots from the European Vegetation Archive (EVA) and other databases. Then we determined diagnostic, constant and dominant species for each habitat by calculating species‐to‐habitat fidelity and constancy (occurrence frequency) in the classified data set. Finally, we mapped the plot locations for each habitat.ResultsFormal definitions were developed for 199 habitats at Level 3 of the EUNIS hierarchy, including 25 coastal, 18 wetland, 55 grassland, 43 shrubland, 46 forest and 12 man‐made habitats. The expert system classified 1,125,121 vegetation plots to these habitat groups and 73,188 to other habitats, while 63,064 plots remained unclassified or were classified to more than one habitat. Data on each habitat were summarized in factsheets containing habitat description, distribution map, corresponding syntaxa and characteristic species combination.ConclusionsEUNIS habitats were characterized for the first time in terms of their species composition and distribution, based on a classification of a European database of vegetation plots using the newly developed electronic expert system EUNIS‐ESy. The data provided and the expert system have considerable potential for future use in European nature conservation planning, monitoring and assessment.