Plants in the Habitats Directive: trends in numbers
Three of the plant species in the Habitats Directive occur in the Netherlands: creeping marshwort, fen orchid and floating water-plantain. A fourth species in the Directive, summer lady's tresses, was already extinct in the Netherlands by 1950.
Trends in creeping marshwort
Creeping marshwort grows in water meadows (i.e. meadows that are shallowly flooded in winter). Prior to 1950 it used to occur in various parts of the Netherlands. In the first half of the 20th century it declined; it was last seen near Zuiddorpe in Zeeuws-Vlaanderen. It was thought to have gone extinct in the Netherlands: its disappearance was attributed to changes in water management.
In 1983 the species reappeared in Zeeuws-Vlaanderen. Other sightings followed, mostly in Zeeland, but also in Overijssel and the adjoining part of Gelderland. It has also recently been rediscovered in Brabant. However, not all the recently discovered occurrences are permanent.
Trends in the fen orchid
The fen orchid grows in dune slacks, quaking bogs and on tidal sand flats. It used to occur throughout the Netherlands, but its localities in Gelderland, Twente, Brabant and Limburg have been lost because of land reclamation and the cessation of upward seepage. It has disappeared from the coastal dunes of Noord-Holland and Zuid-Holland because these dunes are now used to collect drinking water. The species is currently still growing on the Wadden islands, in northwest Overijssel and in a few other localities.
Trends in floating water-plantain
The floating water-plantain is most abundant in the eastern and southern provinces. It also grows in scattered localities along the coast and in carr peat areas. The species has declined and has disappeared from certain regions, including west Overijssel and the Gelderse Vallei. The floating water-plantain currently tends to be found along watercourses (brooks and ditches) in intensively used farmland. It only survives in pools and fens if these are cleaned regularly.
Trends in summer lady's tresses
The summer lady's tresses grows in well developed wet oligotrophic meadows and in species-rich heaths on generally calcareous soil. It used to grow in southeast Brabant and the adjoining part of Limburg. It has disappeared from all localities because of the effects of water draw-down and land reclamation. The most recent well-documented sightings of the species date from 1936. Later sightings in Budel have not been verified.
Creeping marshwort, fen orchid and floating water-plantain are on the Red List of vascular plants and in Annexes II and IV of the Habitats Directive. The summer lady's tresses is also on the Red List of vascular plants and is in Annex IV of the Habitats Directive.
Technical note
The data are from FLORON and have been taken from the Atlas van de Nederlandse Flora, the Florivon historical flora databank, and the Florbase national flora databank. Other sources are the national flora monitoring network (important species) and data from provinces and land managers. As floating water-plantain has only been monitored thoroughly since 1980, its decline may actually be greater than the figures suggest.
References
- Groen, C.L.G. en B. Vreeken (2002). Voorkomen van Habitatrichtlijnsoorten vaatplanten in Nederland vóór en na 1980. Rapport 2002.27. Stichting FLORON. Leiden.
