caa a22 4500 605516707 CHVBK 20210128100715.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s10533-015-0104-5 doi (NATIONALLICENCE)springer-10.1007/s10533-015-0104-5 Benthic nitrogen metabolism in a macrophyte meadow ( Vallisneria spiralis L.) under increasing sedimentary organic matter loads [Elektronische Daten] [Elisa Soana, Mariachiara Naldi, Stefano Bonaglia, Erica Racchetti, Giuseppe Castaldelli, Volker Brüchert, Pierluigi Viaroli, Marco Bartoli] Organic enrichment may deeply affect benthic nitrogen (N) cycling in macrophyte meadows, either promoting N loss or its recycling. This depends upon the plasticity of plants and of the associated microbial communities, as those surrounding the rhizosphere. Rates of denitrification, dissolved inorganic N fluxes and N uptake were measured in sediments vegetated by the submerged macrophyte Vallisneria spiralis L. under increasing organic matter loads. The aim was to investigate how the combined N assimilation and denitrification, which subtract N via temporary retention and permanent removal, respectively, do vary along the gradient. Results showed that V. spiralis meadows act as regulators of benthic N cycling even in organic enriched sediments, with negative feedbacks for eutrophication. A moderate organic load stimulates N uptake and denitrification coupled to nitrification in the rhizosphere. This is due to a combination of weakened competition between macrophytes and N cycling bacteria and enhanced radial oxygen loss by roots. An elevated organic enrichment affects N uptake due to hostile conditions in pore water and plant stress and impairs N mineralisation and its removal via denitrification coupled to nitrification. However, the loss of plant performance is almost completely compensated by increased denitrification of water column nitrate, resulting in a shift between the relative relevance of temporary and permanent N removal processes. Springer International Publishing Switzerland, 2015 Organic enrichment nationallicence Vallisneria spiralis nationallicence Radial oxygen loss nationallicence N fluxes nationallicence Denitrification nationallicence N uptake nationallicence Soana Elisa Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy aut Naldi Mariachiara Department of Life Sciences, University of Parma, Viale G.P. Usberti 33/A, 43124, Parma, Italy aut Bonaglia Stefano Department of Geological Sciences, Stockholm University, Svante Arrheniusväg 8 C, 106 91, Stockholm, Sweden aut Racchetti Erica Department of Life Sciences, University of Parma, Viale G.P. Usberti 33/A, 43124, Parma, Italy aut Castaldelli Giuseppe Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy aut Brüchert Volker Department of Geological Sciences, Stockholm University, Svante Arrheniusväg 8 C, 106 91, Stockholm, Sweden aut Viaroli Pierluigi Department of Life Sciences, University of Parma, Viale G.P. Usberti 33/A, 43124, Parma, Italy aut Bartoli Marco Department of Life Sciences, University of Parma, Viale G.P. Usberti 33/A, 43124, Parma, Italy aut Biogeochemistry Springer International Publishing 124/1-3(2015-05-01), 387-404 0168-2563 124:1-3<387 2015 124 10533 https://doi.org/10.1007/s10533-015-0104-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10533-015-0104-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Soana Elisa Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy aut NATIONALLICENCE 700 1- Naldi Mariachiara Department of Life Sciences, University of Parma, Viale G.P. Usberti 33/A, 43124, Parma, Italy aut NATIONALLICENCE 700 1- Bonaglia Stefano Department of Geological Sciences, Stockholm University, Svante Arrheniusväg 8 C, 106 91, Stockholm, Sweden aut NATIONALLICENCE 700 1- Racchetti Erica Department of Life Sciences, University of Parma, Viale G.P. Usberti 33/A, 43124, Parma, Italy aut NATIONALLICENCE 700 1- Castaldelli Giuseppe Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy aut NATIONALLICENCE 700 1- Brüchert Volker Department of Geological Sciences, Stockholm University, Svante Arrheniusväg 8 C, 106 91, Stockholm, Sweden aut NATIONALLICENCE 700 1- Viaroli Pierluigi Department of Life Sciences, University of Parma, Viale G.P. Usberti 33/A, 43124, Parma, Italy aut NATIONALLICENCE 700 1- Bartoli Marco Department of Life Sciences, University of Parma, Viale G.P. Usberti 33/A, 43124, Parma, Italy aut NATIONALLICENCE 773 0- Biogeochemistry Springer International Publishing 124/1-3(2015-05-01), 387-404 0168-2563 124:1-3<387 2015 124 10533