Progetto pilota per lo studio multidisciplinare ed integrato su un sottobacino del Lago Maggiore

No abstract availableComposizione granulometrica del sedimento; campionament

Idrochimica lacustre e dei tributari, bilancio dei nutrienti

No abstract availabl

Chimica lacustre

No abstract availableChimismo di base, composti dell\u27azoto, composti del forsforo, ossigeno disciolto, silicati reattiv

Idrochimica lacustre e dei tributari, bilancio dei nutrienti

No abstract availabl

A non-deterministic approach to forecasting the trophic evolution of lakes

Limnologists have long recognized that one of the goals of their discipline is to increase its predictive capability. In recent years, the role of prediction in applied ecology escalated, mainly due to man\u27s increased ability to change the biosphere. Such alterations often came with unplanned and noticeably negative side effects mushrooming from lack of proper attention to long-term consequences. Regression analysis of common limnological parameters has been successfully applied to develop predictive models relating the variability of limnological parameters to specific key causes. These approaches, though, are biased by the requirement of a priori cause-relation assumption, oftentimes difficult to find in the complex, nonlinear relationships entangling ecological data. A set of quantitative tools that can help addressing current environmental challenges avoiding such restrictions is currently being researched and developed within the framework of ecological informatics. One of these approaches attempting to model the relationship between a set of inputs and known outputs, is based on genetic algorithms and programming (GP). This stochastic optimization tool is based on the process of evolution in natural systems and was inspired by a direct analogy to sexual reproduction and Charles Darwin\u27s principle of natural selection. GP works through genetic algorithms that use selection and recombination operators to generate a population of equations. Thanks to a 25-years long time-series of regular limnological data, the deep, large, oligotrophic Lake Maggiore (Northern Italy) is the ideal case study to test the predictive ability of GP. Testing of GP on the multi-year data series of this lake has allowed us to verify the forecasting efficacy of the models emerging from GP application. In addition, this non-deterministic approach leads to the discovery of non-obvious relationships between variables and enabled the formulation of new stochastic models

Model simulations of the ecological dynamics induced by climate and nutrient load changes for deep subalpine Lake Maggiore (Italy/Switzerland)

Climate warming affects lake ecosystems both through its direct effect on the phenology of species and through the alteration of the physical and chemical environments, which in turn affect community composition. In deep lakes, stratification enhancement and mixing reduction have already been observed, leading to hypolimnetic anoxia and to the rise of cyanophytes. The increase in stability depends on the rise of air temperature due to global emissions of greenhouse gases (GHG). Primary production could then either increase with rising epilimnetic temperature and buoyancy or decrease as fewer nutrients are upwelled from deep layers. The prevailing outcome, as well as the quantitative and temporal dynamics of all climate-induced modifications, depend on the specific lake characteristics. Individual analyses are then needed, one-dimensional coupled hydrodynamic-ecological numerical models being suitable tools for such predictions. Here, we simulated with GLM-AED2 (General Lake Model – Aquatic EcoDynamics) the 2020-2085 dynamics of the oligomictic and oligotrophic deep subalpine Lake Maggiore (Italy/Switzerland), according to the Swiss Climate Change Scenarios CH2011. Multiple realisations were performed for each scenario with random meteorological series obtained from the Vector-Autoregressive Weather Generator (VG), highlighting the uncertainties related to meteorology. Increase and decrease of nutrient loads were also tested. Results show that anoxia would occur in the hypolimnion regardless of nutrient input reduction, unless global GHG emissions were immediately reduced. Total phytoplankton biomass would be weakly affected by climate change, strongly depending on nutrient input, yet water warming would cause cyanophytes to compete with diatoms. Therefore, the fate of Lake Maggiore would be tied to both global and local environmental policies

Indagini limnologiche nell\u27area antistante la Foce del Torrente San Bernardino (Sopralluogo del 2 Dicembre 2008)

No abstract availabl

The water chemistry of some shallow lakes in Northern Patagonian and their nitrogen status in comparison with remote lakes in different regions of the globe

Eighteen small shallow lakes located in the Northern Patagonian Lake District, in southern South America, were sampled in 2001 and analysed for the main chemical variables (pH, conductivity, alkalinity, major ions and nutrients). The study lakes span a wide geographical and altitudinal range and belong partly to the Pacific and partly to the Atlantic watershed. The main aim of this study was to investigate the relationships between water chemistry and physical/geographical properties of these lakes. Secondly, the nitrogen content of the lakes was considered in detail, and results compared to those obtained in previous studies carried out in other remote areas of the globe (the Central Southern Alps in Italy, the Sierra da Estrela region in Portugal, the Svalbard Islands in the Arctic, the Khumbu-Himal region in Nepal, and the Terra Nova Bay area in Antarctica). In the Alps, lakes are characterised by markedly high nitrogen concentrations, manly as nitrate, due to the high inputs of nitrogen compounds from downwind sources like the Po Plain in Northern Italy. Conversely, lakes at remote locations such as the Andes, Antarctica and Himalaya are characterised by a low nitrogen content, mainly as organic nitrogen. This status is related to the limited atmospheric inputs of nitrogen affecting these regions

Evoluzione stagionale e a lungo termine delle caratteristiche chimiche del Lago Maggiore e bilancio dei nutrienti a Lago (Azoto e Fosforo)

Not availableRicerche sull\u27evoluzione del Lago Maggiore. Aspetti limnologici. Programma triennale 2013-2015. Campagna 2013. Evoluzione stagionale e a lungo termine delle caratteristiche chimiche del Lago Maggiore e bilancio dei nutrienti a Lago (Azoto e Fosforo). Chimica di base e contenuto ionico delle acque lacustri. Composti dell\u27Azoto e del Fosforo e silicati. Ossigeno disciolto. Metalli in tracce. Apporti chimici dai tributari: caratteristiche chimiche e chimico-fisiche; concentrazioni medie areali; carichi chimici e bilanci di Azoto e Fosforo

Effects of water level management on lake littorals and downstream river areas

The Interreg “Parks Verbano Ticino” (PVT) project was conceived within the technical committee dedicated to the “Experimentation of the regulation of the Lake Maggiore levels” following the requests of the water manager to raise the spring-summer maximum levels of the lake compared to the levels normally held in the same period to respond to the industrial, agricultural, touristic, and environmental needs...