Discriminating among multiple components affecting bulk atmospheric deposition chemistry: a multivariate approach using data from a forest plot in Calabria (Southern Italy)

This study examines the relationships between meteorology and atmospheric deposition chemistry on the basis of 4 years of monitoring in an area of Calabria (Piano Limina) under the National Integrated Programme for the Control of Forest Ecosystems. The location of the area and its low anthropogenic impact meant that phenomena of locally originating alkaline dust deposition could be distinguished from those originating long distances away. The analysis performed on the whole dataset revealed the interaction between temperature, solar radiation and ionic concentrations; the effects of the atmospheric transport of compounds, with lower concentrations during calm conditions; and a marked increase of calcium, alkalinity and pH with winds from W-SW, owing to the transport of alkaline dust from North Africa, in agreement with thematic maps on the synoptic scale. The possible influence of two volcanic events deriving from Stromboli and Etna is discussed. After elimination of the Saharan dust and volcanic events, a multivariate analysis showed the effects of compounds deriving from anthropogenic activities. Sulphate, nitrate and ammonium were closely correlated with NW winds; air masses from this direction come from the continental land mass and the sea, crossing the Calabrian plain before being deposited as precipitation on the Apennine chain. The component from NW also includes a high marine contribution, with maximum values of chloride and sodium

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

Water chemistry and trophic evaluation of Lake Albano (Central Italy): a four year water monitoring study

The crater lake Lake Albano is an increasingly diminishing water resource in terms of volume, the lake level has dropped more than four meters since the 1960s, and water quality resulting from elevated levels of nitrogen and phosphorus. The area of the lake, and the volcano as a whole, is also considered to be geologically hazardous due to continual shallow seismic activity, gaseous emissions and hydrothermal activity. Therefore, most research has been focussed on the geological aspects of the Albano lake system, whilst long-term limnological studies have been lacking. A meromictic classification was given to the lake, but this was based on one year studies of the surface water only. Presented and discussed are the results of a water chemistry and biological study of the full depth profile of Lake Albano from 2004 to 2008. During winter 2005-2006 the lake underwent a complete overturn, resulting in an influx of nutrient rich hypolimnetic water into the upper productive layers and oxygenated epilimnetic water into the deepest water layers. The effect of full overturn on the phytoplankton community is described and compared with those of meromictic years. The interplay between natural and anthropological processes on water quality and water usages is also discussed

A century of limnological research in the Historical Archive of the CNR ISE

Since 2010, the Historical Archive of the Italian Institute of Ecosystem Studies has been subject to an extensive rearrangement and improvement program. The Archive contains original documents (such as letters, administrative documents, notarial deeds, drawings and prints, photographic plates, photographs) recording the scientific and administrative activities from the foundation of the Institute (1938) till its annexation to the Italian National Research Council (1977). Furthermore, it hosts some material documenting studies that were conducted in the first decades of the XIX Century, mainly by Marco De Marchi (1872-1936), a pioneer of limnology in Italy, and Edgardo Baldi (1899-1951), the first director of the Institute. This collection is a cornerstone of more than a century of scientific research in limnology, which also benefitted from frequent international contacts with scientists and ecological associations. The reorganization of the material in the Historical Archive was planned in consultation with the Soprintendenza Archivistica of the Piedmont Region, which is the legal authority responsible for the public archives in the Piedmont Region. Beginning in 2012, the information contained in the Archive has been digitized using the software xDams, an open version software source of Regesta?. In 2014, part of the digitized material was made available on the web site: http://www.ise.cnr.it/archivio. These activities were conducted thanks to the contribution of the Fondazione Cassa Risparmio di Torino and Fondazione Comunitaria VCO, which funded two temporary staff for the reorganisation of the Historical Archive, including the physical preservation and digitalisation of the documents. These activities are part of the CNR mission within the European Digital Agenda, and the CNR contribution to the development of scientific thought

Periphyton changes over 20 years of chemical recovery of Lake Orta, Italy: differential response to perturbation of littoral and pelagic communities

Lake Orta, a large Italian subalpine lake, has a long history of industrial pollution by acid, ammonia, and metals. A whole-lake liming treatment in 1989-1990 led to a gradual increase in pH (from 4.4 to 7) and a concomitant decline in ammonia (from 2.5 to 0.05 mg L-1) and metal concentrations (e.g., copper: from 35 to 3 μg L-1). In this study, we examine the response of the littoral zone, in terms of chemistry and periphyton assemblages, to contamination and recovery of Lake Orta. We compare these findings with a long-term data set of chemistry and phytoplankton collected in the pelagic zone. We sampled periphyton at two sites from the liming period (1989) through 2010 when the lake approached chemical equilibrium. Chemical variables collected in the littoral zone near the periphyton samples followed the same temporal trends observed in the pelagic zone. Chlorophytes, the dominant algae in the preliming period, progressively waned after the calcium carbonate addition. Diatom importance gradually increased to reach up to 80% of the total biovolume in the most recent years. There was a clear shift in the diatom taxonomic composition over the study period. Acidophilous Pinnularia subcapitata var. hilseana and metal-tolerant Achnanthes minutissima were dominant before liming. With the progressive increase in pH and decline in metal concentrations, there was successively the dominance of Fragilaria nanoides (formerly identified as Synedra tenera) and Cymbella microcephala in the transition period and of circumneutral Navicula cryptocephala, N. radiosa, and Synedra ulna in the most recent period. Pelagic diatoms were more affected than benthic diatoms by the industrial pollution and their recovery after the liming intervention was slower. Whereas present periphyton diatom assemblages are similar to those observed in nearby unpolluted Lake Mergozzo, pelagic assemblages are still in transition from severe disturbance towards characteristics reported before pollution. Our results suggest that the littoral zone may have acted as a refugium during contamination providing an inoculum for pelagic recolonization

Lake Orta chemical status 25 years after liming: problems solved and emerging critical issues

Lake Orta, located in Piedmont, northwestern Italy, has been severely affected by industrial pollution since the 1930s. A successful liming intervention, performed in 1988-1990, returned pH levels in the lake to neutrality, and accelerated the reduction of aqueous trace metal concentrations. In this paper, we present an update knowledge of the chemical status of Lake Orta, focusing on the data collected from 1990 to 2014. In this period we sampled the lake at its deepest point (Qualba station), on a monthly (1990-2000) or seasonal (since 2001) basis. Samples were collected at nine depths through the water column, and analyzed for pH, conductivity, alkalinity, major ions, nutrients, and trace metals. Collectively, these data allowed us to evaluate the long-term response of the lake to the restoration treatment, with particular regard to its acid-base status; they also provided insights into emerging or potential critical issues, including eutrophication and re-suspension of trace metals that still linger in the lake. Furthermore, the evaluation of the present chemical condition of the lake is a precondition for any successive restoration measure, such as fish introduction. The recent data confirmed the lake's water quality has recovered, i.e. returned to a pre-pollution chemical state. Lake water values of pH and concentrations of ammonium, sulphate and base cations have stabilized. Alkalinity and nitrate concentrations are also expected to reach stable level in the next few years. Levels of nitrate, reactive silica, and phosphorus compounds are now regulated by algal uptake, providing indirect evidence of a partial biological recovery. For instance, both the inter-annual average decline and the reappearance of a seasonal signal in silica confirmed the presence of a stable diatom community. The lake is presently oligotrophic, and concentrations of both N and P compounds are steady and low throughout the year. However, a monthly check of nutrient levels of the lake and inflowing waters is recommended. The monitoring of base chemical variables, major ions and trace metals should be maintained to assess the overall status of the ecosystem in response to various drivers, including climate change

Atmospheric Deposition and Soil Solution Working Ring Test 2010 Laboratory ring test for deposition and soil solution sample analyses for the laboratories participating in the EU/Life+ FutMon Project

A second Working Ring Test (WRT) was organised within the framework of the EU/Life+ FutMon Project ("Further Development and Implementation of an EU-level Forest Monitoring System", LIFE07 ENV/D/000218), to evaluate the overall performance of the laboratories responsible for analysing atmospheric deposition and soil solution samples in European forests, and to verify improvements in the analytical quality resulting from the QA/QC work carried out in the laboratories which participated in previous WRTs organized in the framework of the UN/ECE ICP Forests Monitoring Programme. The WRT was carried out in accordance with International ISO and ILAG guide proficiency test both for sample preparation and numerical elaboration of the results. Five natural atmospheric deposition and soil solution samples and 3 synthetic solutions were distributed to 42 laboratories for analysis using their routine methods for the following variables: pH, conductivity, calcium, magnesium, sodium, potassium, ammonium, sulphate, nitrate, chloride, total alkalinity, total dissolved nitrogen (TDN), dissolved organic carbon (DOC). Two tolerable limits were defined for each variable on the basis of the measured value, the results of previous WRTs, a comparison with the Data Quality Objectives of other international networks, and the importance of the variable in deposition and soil solution monitoring. In the ring test 12% of the results from all the laboratories did not fall within the tolerable limits. This enabled us to identify those variables and laboratories for which improvements in analytical performance are required. The results of the exercise clearly show that the use of data check procedures, as described in the ICP Forests manual for sampling and analysis of atmospheric deposition, makes it possible to detect the presence of inaccurate or outlying results, and would therefore greatly improve the overall performance of the laboratories. A discussion of the improvement of the results in this WRT compared to the previous WRTs is also included, showing a relevant improvent for several variables and underlining the importance of participating to these exercises for the overall analytical quality of the monitoring network

Again on the Excel sheet for testing water chemical analyses (atmospheric deposition, runoff, soil water)

A simple Excel sheet to perform QA/QC on deposition and soil solutin sample

Status and trend of atmospheric deposition chemistry at the CONECOFOR plots, 1998-2005

Ion deposition in the open field and under the canopy was monitored in 13 CONECOFOR plots during 1998-2005. In spite of the remote location of most plots, atmospheric deposition carries considerable amounts of anthropogenic ions (sulphate, nitrate and ammonium). Deposition acidity is buffered by the deposition of base cations, partially due to the long-range transport of Saharan dust. In the study period, sulphate deposition and deposition acidity significantly decreased, because of the decrease in sulphur dioxide emissions in Europe, while nitrate and ammonia deposition did not show a clear temporal pattern

Results from the Italian participation in the International Co-operative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes (ICP Waters)

This paper describes the research activity carried out by the Istituto Italiano di Idrobiologia of the CNR, on behalf of the Ministero dell'Ambiente, Servizio Inquinamento Atmosferico e Acustico, in the context of the Italian participation in the International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes (ICP Waters). Atmospheric deposition chemistry shows that nitrate increased and sulphate decreased in the 70's and 80's, while acidity started to decrease in the early 90's. The studied rivers and lakes show variations in sulphate and nitrate in agreement with those of atmospheric deposition. Alkalinity is mainly determined by watershed geo-lithology and is always present in the studied lakes and streams; the lowest values of 0-10 μeq l-1 are measured in the high altitude Lake Paione Superiore, which however shows an increasing trend of alkalinity and pH