| Title | Nitrogen budget of Lago Maggiore: the relative importance of atmospheric deposition and catchment sources |
| Abstract | Hydrological and chemical data of 1996 and 1997 are used to evaluate the relative contributions of atmospheric deposition and
urban/industrial wastewaters to the nitrogen budget of Lago Maggiore. The atmospheric load of nitrogen was about 80% of the total
input to the lake, with negligible variations in dry (1997) and wet (1996) years. A comparison of the two study years with the yearly
N budgets evaluated from 1978 to 1998, showed that the N load was higher with increasing amounts of precipitation/water inflow.
Soils and vegetation act as N sinks; the % retention varies between 40-60% for the forested catchments with low population density
in the central-northern part of the basin, to values close to zero or even negative in the south, indicating a net leaching from the
soils. The Traaen & Stoddard (1995) approach revealed that all the catchments of the major inflowing rivers were oversaturated
with nitrogen. The long-term trend of nitrogen concentrations in Lago Maggiore (1955-99) is analogous to the trend for atmospheric
deposition (1975-99), which is related to emissions of nitrogen oxides and ammonia in the atmosphere. The relationships between
the present N load and in-lake concentrations are discussed using a budget model, which is also used to infer the pristine load of N.
The close relationships between N trends in lakes Maggiore, Como and Iseo, and the geographical and anthropogenic features common
to their catchments, suggest that the results obtained for Lago Maggiore can be extended to a wider area |
| Source | Journal of limnology (Testo stamp.) 60 (1), pp. 27–40 |
| Keywords | Lago Maggiorenitrogen budgetatmospheric depositionriver watercatchment |
| Journal | Journal of limnology (Testo stamp.) |
| Editor | Istituto per lo Studio degli Ecosistemi., Verbania Pallanza, Italia |
| Year | 2001 |
| Type | Articolo in rivista |
| Authors | Rosario MOSELLO*, Alberto BARBIERI1), Maria Cristina BRIZZIO, Alcide CALDERONI, Aldo MARCHETTO, Stefania PASSERA, Michela ROGORA and Gabriele TARTARI |
| Text | 252590 2001 Lago Maggiore nitrogen budget atmospheric deposition river water catchment Nitrogen budget of Lago Maggiore the relative importance of atmospheric deposition and catchment sources Rosario MOSELLO , Alberto BARBIERI1 , Maria Cristina BRIZZIO, Alcide CALDERONI, Aldo MARCHETTO, Stefania PASSERA, Michela ROGORA and Gabriele TARTARI C.N.R. Istituto Italiano di Idrobiologia, L.go Tonolli 50, 28922 Verbania Pallanza, Italy Laboratorio Studi Ambientali, Sezione Protezione Aria e Acqua, Lugano Paradiso, Canton Ticino, Switzerland Hydrological and chemical data of 1996 and 1997 are used to evaluate the relative contributions of atmospheric deposition and urban/industrial wastewaters to the nitrogen budget of Lago Maggiore. The atmospheric load of nitrogen was about 80% of the total input to the lake, with negligible variations in dry 1997 and wet 1996 years. A comparison of the two study years with the yearly N budgets evaluated from 1978 to 1998, showed that the N load was higher with increasing amounts of precipitation/water inflow. Soils and vegetation act as N sinks; the % retention varies between 40 60% for the forested catchments with low population density in the central northern part of the basin, to values close to zero or even negative in the south, indicating a net leaching from the soils. The Traaen Stoddard 1995 approach revealed that all the catchments of the major inflowing rivers were oversaturated with nitrogen. The long term trend of nitrogen concentrations in Lago Maggiore 1955 99 is analogous to the trend for atmospheric deposition 1975 99 , which is related to emissions of nitrogen oxides and ammonia in the atmosphere. The relationships between the present N load and in lake concentrations are discussed using a budget model, which is also used to infer the pristine load of N. The close relationships between N trends in lakes Maggiore, Como and Iseo, and the geographical and anthropogenic features common to their catchments, suggest that the results obtained for Lago Maggiore can be extended to a wider area 60 Nitrogen budget of Lago Maggiore the relative importance of atmospheric deposition and catchment sources N_LagoMaggiore.pdf Articolo in rivista Istituto per lo Studio degli Ecosistemi. 1129 5767 Journal of limnology Testo stamp. Journal of limnology Testo stamp. J. limnol. Testo stamp. Journal of limnology. Testo stamp. michela.rogora ROGORA MICHELA rosario.mosello MOSELLO ROSARIO gabriele.tartari TARTARI GABRIELE |
