This gradient occurs at the border of an artificial pond on a plastic foil covered with coarse river sand, situated in a Calluna heath vegetation. This situation has created a gradient from weteutrophic to dry-oligotrophic. Along this gradient three zones A, B and C have developed, each with its characteristic species: A at the water edge on the river sand, B on the slope towards the heath and C the heath itself. None of the species has been planted by the owner of the estate on which the pond is situated.