| Text | 329226 2012 Nitrogen Lakes Phytoplankton Benthos Fish Macrophytes Analisi della relazione tra le concentrazione di azoto e la composizione delle comunita acquatiche Giuseppe Morabito; Aldo Marchetto; Michela Rogora; Martina Austoni; Pietro Volta; Paolo Sala; Gabriele A. Tartari; Igor Cerutti; Angela Boggero; Silvia Zaupa; Alessandro Oggioni; Antonella Luglie; Maria Antonietta Mariani; Bachisio M. Padedda; Nicola Sechi; Elio Sesia; Teo Ferrero; Pierluigi Fogliati; Gabriella Fornaro; Mario Pannocchia; Francesca Vietti; Marzia Ciampittiello Giuseppe Morabito1, Aldo Marchetto1, Michela Rogora1, Martina Austoni1, Pietro Volta1, Paolo Sala1, Gabriele A. Tartari1, Igor Cerutti1, Angela Boggero1, Silvia Zaupa1, Alessandro Oggioni1,2, Antonella Luglie3, Maria Antonietta Mariani3, Bachisio M. Padedda3, Nicola Sechi3, Elio Sesia4, Teo Ferrero4, Pierluigi Fogliati5, Gabriella Fornaro5, Mario Pannocchia5, Francesca Vietti6 Marzia Ciampittiello1 1CNR ISE, Verbania Pallanza VB 2CNR IREA, Unita Operativa di Supporto, Milano 3Dipartimento di Scienze Botaniche, Ecologiche e Geologiche, Universita di Sassari 4ARPA Piemonte, Struttura Specialistica Qualita delle Acque, Asti 5ARPA Piemonte, Dipartimento di Torino, Presidio Territoriale di Ivrea 6ARPA Piemonte, Dipartimento di Biella This report presents an analysis of the relationships between environmental variables and organisms belonging to the four biotic communities used to define the lake s ecological quality, according to provisions of the Italian legislation D.Lgs. 260, November 2010 and the European Water Framework 2000/6. The data analyzed were collected during the sampling surveys carried out within InHabit Project in 13 water bodies, 7 in Piedmont and 6 in Sardinia respectively. In particular, the aim of the study was to evaluate the possible effects of nitrogen on biotic communities. Phytoplankton community shown the clearer responses according to the result of multivariate analysis, total nitrogen and ammonium nitrogen are among the most significant factors explaining the relationships among phytoplankton orders, species and environmental variables. In particular, cyanobacteria increased considerably with increasing availability of ammonium nitrogen. Conversely, high concentrations of this compound suppress the development of diatoms. Other algal groups show a nonlinear response with respect to nitrogen, with a possible limitation under low levels of nitrogen and an inhibition at higher levels. A comparative analysis, carried out to evaluate the response to the gradient of total phosphorus, shows that this nutrient is not as selective as nitrogen in controlling the structure of the algal assemblage in different environmental conditions. Other biotic communities did not show a clear relationship with nitrogen, but they rather responded to the trophic gradient as a whole responses by macroinvertebrates seem, especially in the analysis of functional groups, complex and difficult to discriminate, highlighting a possible shifting of the food web towards the presence of large carnivores at high trophic status. Regarding the fish, the results show that nitrogen alone does not seem to be an important controlling factor for the fish communities. However together with the phosphorus, is one of the main elements controlling both biomass and size of the fish fauna, as well as the presence of tolerant, omnivorous or benthofagous species. In conclusion, the results of our analysis highlight the need for a greater emphasis on nitrogen inputs, which, especially in cases of nitrogen carried by atmospheric deposition, may even affect lake ecosystems relatively distant from direct impacts of human activities, thus altering the structure of biotic communities. Deliverable del progetto INHABIT Local hydro morphology, habitat and RBMPs new measures to improve ecological quality in South European rivers and lakes Deliverable 2012_Deliverable_I2d7_INHABIT.pdf Rapporto di ricerca Research report martina.austoni AUSTONI MARTINA ZAUPA SILVIA SALA PAOLO igorio.cerutti CERUTTI IGORIO angela.boggero BOGGERO ANGELA aldo.marchetto MARCHETTO ALDO giuseppe.morabito MORABITO GIUSEPPE marzia.ciampittiello CIAMPITTIELLO MARZIA michela.rogora ROGORA MICHELA alessandro.oggioni OGGIONI ALESSANDRO pietro.volta VOLTA PIETRO gabriele.tartari TARTARI GABRIELE TA.P04.016.004 Ecologia teorica e applicata degli ecosistemi acquatici |
