Some Notes on Skallingens Salt Marsh Vegetation and its Habitat

During the excursion of the International Society for Plant Geography and Ecology in 1956 the author was in a position to stay some days at Skalling-Laboratory to study the salt marsh vegetation of the Peninsula (Fig. 1). In the past 25 years silt has been deposited mainly on a strip along the Wadden Sea coast, the so-called outer marshes. These sedimentation conditions have created a bank-and-basin-landscape (Fig. 2). The inner marshes have been modificated only slightly in this respect. The vegetation of an ungrazed strip overlapping both outer and inner salt marshes is described in detail. On the outer marshes the following communities are distinguished: Zosteretum nanae (fragmentary), Salicornietum europaeae, Puccinellietum maritimae divided into an initial and an optimal phase, Halimionetum porlulacoidis, Artemisietum maritimae and very scarcely, a sociation with Agropyron litorale, a species which is new for Skallingen. The different views about synsystematic limitation of the Artemisietum maritimae are discussed in detail; the author agrees with the view of Weevers (1940). From the inner marshes are described: Salicornietum europaeae, Puccinellietum maritimae divided into a phase rich in therophytes and a phase with Limonium vulgare and Plantago maritima, Juncetum gerardi and Saginetum maritimae. The taxonomy of the forms of Festuca rubra and Agrostis stolonifera occurring on these marshes is discussed briefly. Arguments for a change of the association’s name from Armerieto-Festucetum to the older name of Juncetum gerardi are tentatively proposed. A separation of the Puccinellio-Salicornion into the alliances Thero-Salicornion and Puccinellion maritimae is preferred and discussed briefly. The vegetation was found to react to changes in the environment with the establishment and extension of Halimione portulacoides and the extension of Limonium vulgare and Artemisia maritima. Halimione pedunculata disappeared as well as Glaux maritima, Juncus gerardi and Armeria maritima in the Artemisietum maritimae. On the outer marshes species decreasing their ecologie amplitude and partly their cover are Puccinellia maritima, Aster tripolium, Suaeda maritima, Spergularia marginata and Plantago maritima. Contrary to the above mentioned species Salicornia europaea and Triglochin maritimum have extended on the outer marshes in consequence of progressive sedimentation resp. changed soil water conditions. Finally synecological trends have been discussed. The most important ones are the development of the Halimionetum portulacoidis and the establishment of a sociation with Agropyron litorale on the outer salt marshes. It is expected that these trends will proceed on a limited scale in the future.