Mellum is a small dune island (6 square km) in the Lower Saxony Waddensea National Park (German Bight). It is located north of the Jade Bay in the German Bight. Compared with other East Frisian Islands this young island is quite isolated from the mainland and other islands (> 6km distance) as one can see on the map below.
Dune succession reached the stage of white dunes with a maximum height of 4m (the Northern Dune complex in the north of Mellum). Smaller dune complexes can be found in the south and west. The middle of Mellum is dominated by a crouch grass zone (Agropyron repens and other grasses). Large salt marsh complexes cover the east, central north, and central west, whereas extensive sand plates form the outer east and west of Mellum island.
The "Ringdeichgebiet" was built in Second World War between 1940 and 1942 (Haeseler 1988). Its building was by far the most important interference in the natural colonization of this young island which is developing since the 1870s. The Ringdeich-area is now colonized by many plants and animals which would have no chance to live elsewhere on Mellum island. It is the only part protected from storm tides in the winter; hence it is rich in species.
Mellum island was object of two research projects (from 1984 to 1986 and from 1994 to 1995) carried out by the AG Terrestrial Ecology of the University Oldenburg/Nds. The results of the first project can be found at Meyer & Haeseler (1988, eds.).
References:
Haeseler, V. (1988): Entstehung und heutiger Zustand der jungen Düneninseln Memmert und Mellum sowie Forschungsprogramm zur Besiedlung durch Insekten und andere Gliederfüßer. - Drosera `88: 5-46.
Meyer, K. O. & V. Haeseler (eds.) (1988): Zoologische Beiträge zur Besiedlung der jungen Düneninseln Memmert und Mellum. - Drosera `88: 1-370.