On the hydrological relationship between Petrifying-springs, Alkaline-fens, and Calcareous-spring-mires in the lowlands of North-West and Central Europe; consequences for restoration

(1) Petrifying-springs and Calcareous-spring-mires are threatened ecosystems in Europe and are protected under the Natura 2000 Habitats Directive. In European and national legislations Petrifying-springs and associated tufa cascades, small streams and flushes (7220) are treated as separate entities from Alkaline-fens and Calcareous-spring-mires (7230), each with their own protection and restoration measures. This may, however, create conflicts if the two habitats are physically connected or adjacent to one another: restoration measures aimed at one of the two may have negative effects on the other. (2) The present study focuses on the spatial and temporal relationships between Petrifying-springs and Alkaline-fens with tufa deposition, and discusses consequences of this relationship for restoration of degraded sites. When a Petrifying-spring co-occurs with an Alkaline-fen or Calcareous-spring-mire, restoration measures should take account of the needs of both habitat types.