Grasslands of brackish fen and of mesotrophic fen in Laag-Holland, The Netherlands

Abstract

This chapter talks about the species-rich grasslands on brackish fen and on mesotrophic fens of the Dutch polders north of Amsterdam. In Holland, polders are low-lying tracts of land with human controlled hydrology, enclosed by a dike. Although the brackish grasslands are mainly grazed and the fen grasslands are mainly mown for hay both types have similar management and successional properties. The brackish grasslands in Lower Holland belong to communities of the Lolio-Potentillion anserinae alliance, which are wet, temporally or regularly inundated grasslands, which are usually grazed by cattle. In the Lower Holland area the brackish grasslands are characterised by Trifolium fragiferum, Triglochin palustris, Potentilla anserina and the occurrence of halophytic plant species such as Triglochin maritima, Glaux maritima, Spergularia salina,Carex distans and Juncus gerardii. The most species-rich Triglochin - Juncus gerardii communities occur only in grasslands where an extensive grazing management is maintained during a considerable period of time.Keywords: brackish fen species-rich grasslands; Laag-Holland; Lolio-Potentillion anserinae communities; mesotrophic fens; Triglochin - Juncus gerardii communities