Coastal landscapes and their typical ecosystems like salt marshes and sand dunes are highly dynamic, characterized by steep environmental gradients and controlled by geomorphological, physical and biological processes. In addition, both direct and indirect human impacts are important factors that give shape to the spatial and temporal variation of coastal ecosystems. The conservation of these coastal ecosystems is a major aim of the Wadden Sea Plan (management plan of the Trilateral Cooperation). As a basis for conservation management, sound knowledge about the spatial distribution of coastal ecosystems and their temporal change is required. In the past, multiple regional vegetation or biotope typologies have been used to describe and map plant communities of coastal ecosystems in the Wadden Sea region (e.g. Westhoff & den Held 1969; Dijkema & Wolff 1983; Dierssen 1988; Preising et al. 1990; Schaminée et al. 1995, 1996, 1998; Petersen 2000, 2011; Petersen & Pott 2005; Drachenfels v. 2011). In addition, several regional or national classifications for mapping purposes have been developed (SALT-Code, Rijkswaterstaat, s. Jong de et al. 1998; Staatsbosbeheer-Code, s. Schipper 2002; Ringot-Code, s. Ringot 1992; SH-Code, LKN, s. Stock et al. 2005). For a trilateral assessment, however, these different regional approaches have been shown to be difficult to compare at first sight.
The Trilateral Monitoring and Assessment Programme (TMAP; 1997) aimed to harmonize these different approaches for the Wadden Sea region as a basis for improving conservation management and to reach the conservation targets listed in the Wadden Sea Plan (see CWSS 2010). Since 2000, the TMAP salt marsh expert group developed and discussed a common community typology for the Wadden Sea saltmarshes. This TMAP salt marsh typology, which the expert group endorsed in 2003, encompassed 29 different types or plant communities from the pioneer, low and high salt marshes and from brackish marshes, including reed beds (Bakker et al. 2005, Esselink et al. 2009). It is a simplified aggregation of vegetation types which is based on the presence of characteristic or dominant plant species. The TMAP salt-marsh typology has been widely used for monitoring the extent and composition of this ecosystem in both the Netherlands and in Germany for more than 10 years. In addition, a complementary TMAP dune typology was developed, in which 68 types of dunes and dune slacks are differentiated (Petersen & Lammerts 2005, Lammerts et al. 2009). However, a common TMAP synopsis of coastal ecosystems that covers both salt marshes and dunes of the Wadden Sea region was lacking so far.
The synopsis presented here aims to give a comprehensive overview about the existing salt marsh and dune vegetation types in the Wadden Sea region. Further, a ‘translation’ of these TMAP types to the typologies used in the different regions of the Wadden Sea is given. Last but not least, an assignment of the presented TMAP types to the habitat types protected by the European Fauna-Flora-Habitat directive (European Commission 2007, Drachenfels v. 2012) is also included in the synopsis.
The synopsis consists of two parts: In the first part, the most important TMAP types are presented on separate and similarly arranged pages. Here, information on typical plant species and on plant communities, which belong to this type, is included. Further, the use of the type in mapping programs in the Wadden Sea regions and the assignment to regional typologies are listed. Finally, a picture gives a visual impression of the described TMAP type. In the second part of the synopsis, a complete overview about all TMAP salt marsh and dune types of the Wadden Sea region is presented in a table. We, nevertheless, would like to emphasize that this synopsis is not thought to be used as a field key, allthough it has been successfully practised. Regionally field keys are available for this purpose.
We hope that the synopsis will be widely distributed and repeatedly used by nature conservation in all countries and regions of the Wadden Sea. We are sure that this synopsis will contribute to the harmonization of different typologies of coastal habitats, and that it assists us in the process towards a better understanding of the spatial and temporal variation of coastal habitats in the Wadden Sea region.
Finally, the synopsis has been developed to improve conservation management of coastal habitats in the Wadden Sea region and thus to contribute to the long-term preservation of the Wadden Sea Natural Heritage.
Kai Jensen, Hamburg University, chair of the TMAP expert group