title: Hierarchy of factors exerting an impact on nutrient load of the Baltic Sea and sustainable management of its drainage basin.
abstract: The aim of the paper was to evaluate 23 catchment factors that determine total phosphorus and total nitrogen load to the Baltic Sea. Standard correlation analysis and clustering were used. Both phosphorus and nitrogen loads were found to be positively related to the number of pigs and the human population associated with wastewater treatment plants (WWTPs) per km(2), while the number of cattle and agricultural area were found to influence nitrogen rather than phosphorus load, and the area of forests is negatively related to loads of both nutrients. Clustering indicates an overall north-south pattern in the spatial co-occurrence of socio-ecological factors, with some exceptions discussed in the paper. Positive steps in the Baltic Sea region have already been taken, but much remains to be done. The development of coherent response policies to reduce eutrophication in the Baltic Sea should be based on a comprehensive knowledge base, an appropriate information strategy and learning alliance platform in each drainage river catchments.
authors.affiliation: European Regional Centre for Ecohydrology of the Polish Academy of Sciences, Tylna 3, 90-364 Lodz, Poland; Department of Applied Ecology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland. Electronic address: edytkied@biol.uni.lodz.pl.
authors.forename: Edyta
authors.initials: E
authors.lastname: Kiedrzyńska
authors.affiliation: Department of Computer Science, Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Lodz, Poland; Department for Mathematical Modelling of Physiological Processes, Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Jóźwik
authors.affiliation: Department of Geobotany and Plant Ecology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Kiedrzyński
authors.affiliation: European Regional Centre for Ecohydrology of the Polish Academy of Sciences, Tylna 3, 90-364 Lodz, Poland; Department of Applied Ecology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Zalewski
mesh_terms: D000383:Agriculture; D000818:Animals; D001454:Baltic States; D002417:Cattle; D016000:Cluster Analysis; D003247:Conservation of Natural Resources; D004777:Environment; D005068:Eutrophication; D065928:Forests; D006801:Humans; D009584:Nitrogen / Q000032:analysis*; D009792:Oceans and Seas; D010758:Phosphorus / Q000032:analysis*; D045483:Rivers; D013552:Swine; D014865:Waste Disposal, Fluid
chemical_list: D010758:Phosphorus; D009584:Nitrogen
keywords: Baltic Sea; Cluster analysis; Hierarchy of factors; Management of river catchment; Phosphorus and nitrogen input