Het voorkomen van de Klimopwaterranonkel (Ranunculus hederaceus L.) in Nederland in relatie tot de hydrologie

In the Netherlands Ranunculus hederaceus L. is a relatively rare species, occurring in shallow streams. Measurement of water quality, however, showed that the species is quite tolerant with respect to mineral content and trophic status. In addition to this Ranunculus hederaceus is found in a wide variety of plant communities ranging from mesotraphent to very eutraphent ones. A map is presented showing the distribution of the species in relation to contour lines of the shallow ground water (fig. 3). This map indicates that the species is confined to steep gradients in contour lines adjacent to discharge areas. It is hypothesized that the rareness of this species nowadays in the Netherlands is caused not only by habitat destruction but most of all by changes in the hydrological stability of the sites.