Apium repens (Jacq.) Lag. in Zeeuwsch-Vlaanderen teruggevonden

Apium repens, recorded for the last time in the Netherlands in 1961, was refound in 1983 at some localities in Zeeuwsch-Vlaanderen. In the past it occurred in four kinds of habitat: 1 wet pastures and banks along brooks, inundated in winter; 2 ditches at the fringe of peat areas; 3 wet dune slacks and 4 pastures along old creeks. From the first two kinds of habitat it has disappeared completely. At present one locality is known in the dune area (Schouwen, recorded in 1984). The other recent localities all belong to the fourth type, which is confined to Zeeuwsch-Vlaanderen. Fig. 1 shows the former and recent distribution of A. repens in the Netherlands (last record in the interior c. 1952). The creeks in whose vicinity A. repens was found (fig. 2) have long remained undiked. They have been filled for the greater part with sandy or clayey deposits, which are now in use as pastures. These show a characteristic gradient (fig. 3). On their higher side they border on arable land. Downwards the grassland becomes wetter, with an uneven surface due to trampling. Between it and the open water of the creek a reed and rush belt occurs. The wet, rugged grassland is the habitat of A. repens and also of Scirpus cariciformis. The latter species shows a pattern of decline in the Netherlands similar to that of A. repens. Characteristic of the habitat of. A. repens is a rather open and short vegetation and the water-level being slightly above the surface in winter, slightly below the surface in summer. The chief cause of its disappearance is drainage. Moreover ceasing of grazing of brook banks may have contributed to its elimination from the interior of the Netherlands.