title: Impact of adjacent land use on coastal wetland sediments.
abstract: Coastal wetlands link terrestrial with marine ecosystems and are influenced from both land and sea. Therefore, they are ecotones with strong biogeochemical gradients. We analyzed sediment characteristics including macronutrients (C, N, P, K, Mg, Ca, S) and heavy metals (Mn, Fe, Cu, Zn, Al, Co, Cr, Ni) of two coastal wetlands dominated by Phragmites australis at the Darss-Zingst Bodden Chain, a lagoon system at the Southern Baltic Sea, to identify the impact of adjacent land use and to distinguish between influences from land or sea. In the wetland directly adjacent to cropland (study site Dabitz) heavy metal concentrations were significantly elevated. Fertilizer application led to heavy metal accumulation in the sediments of the adjacent wetland zones. In contrast, at the other study site (Michaelsdorf), where the hinterland has been used as pasture, heavy metal concentrations were low. While the amount of macronutrients was also influenced by vegetation characteristics (e.g. carbon) or water chemistry (e.g. sulfate), the accumulation of heavy metals is regarded as purely anthropogenic influence. A principal component analysis (PCA) based on the sediment data showed that the wetland fringes of the two study sites are not distinguishable, neither in their macronutrient status nor in their concentrations of heavy metals, whereas the interior zones exhibit large differences in terms of heavy metal concentrations. This suggests that seaside influences are minor compared to influences from land. Altogether, heavy metal concentrations were still below national precautionary and action values. However, if we regard the macronutrient and heavy metal concentrations in the wetland fringes as the natural background values, an accumulation of trace elements from agricultural production in the hinterland is apparent. Thus, coastal wetlands bordering croplands may function as effective pollutant buffers today, but the future development has to be monitored closely to avoid breakthroughs due to exceeded carrying capacities.
authors.affiliation: University of Rostock, Faculty of Agriculture and Environment, Landscape Ecology and Site Evaluation, Justus-von-Liebig-Weg 6, 18059 Rostock, Germany; University of Rostock, Faculty of Interdisciplinary Research, Department of Maritime Systems, Albert-Einstein-Straße 3, 18059 Rostock, Germany. Electronic address: svenja.karstens@uni-rostock.de.
authors.forename: Svenja
authors.initials: S
authors.lastname: Karstens
authors.affiliation: University of Rostock, Faculty of Agriculture and Environment, Landscape Ecology and Site Evaluation, Justus-von-Liebig-Weg 6, 18059 Rostock, Germany; University of Rostock, Faculty of Interdisciplinary Research, Department of Maritime Systems, Albert-Einstein-Straße 3, 18059 Rostock, Germany. Electronic address: uwe.buczko@uni-rostock.de.
authors.forename: Uwe
authors.initials: U
authors.lastname: Buczko
authors.affiliation: University of Rostock, Faculty of Agriculture and Environment, Landscape Ecology and Site Evaluation, Justus-von-Liebig-Weg 6, 18059 Rostock, Germany; University of Rostock, Faculty of Interdisciplinary Research, Department of Maritime Systems, Albert-Einstein-Straße 3, 18059 Rostock, Germany. Electronic address: gerald.jurasinski@uni-rostock.de.
authors.forename: Gerald
authors.initials: G
authors.lastname: Jurasinski
authors.affiliation: University of Vienna, Department of Geography and Regional Research, Geoecology, Althanstraße 14, 1090 Vienna, Austria. Electronic address: robert.peticzka@univie.ac.at.
authors.forename: Robert
authors.initials: R
authors.lastname: Peticzka
authors.affiliation: University of Vienna, Department of Geography and Regional Research, Geoecology, Althanstraße 14, 1090 Vienna, Austria. Electronic address: stephan.glatzel@univie.ac.at.
authors.forename: Stephan
authors.initials: S
authors.lastname: Glatzel
keywords: Coastal wetland; Heavy metals; Land use; Phragmites australis; Sediment