A new Expert Decision Support System (EDSS) that can integrate Triad data for assessing environmental risk and biological vulnerability at contaminated sites has been developed. Starting with ecosystem relevance, the EDSS assigns different weights to the results obtained from Triad disciplines. The following parameters have been employed: 1) chemical soil analyses (revealing the presence of potentially dangerous substances), 2) ecotoxicological bioassays (utilizing classical endpoints such as survival and reproduction rates), 3) biomarkers (showing sublethal pollutant effects), and 4) ecological parameters (assessing changes in community structure and functions). For each Triad discipline, the EDSS compares the data obtained at the studied field sites with reference values and calculates different 0–1 indexes (e.g., Chemical Risk Index, Ecotoxicological Risk Index, and Ecological Risk Index). The EDSS output consists of 3 indexes: 1) Environmental Risk Index (EnvRI), quantifying the level of biological damage at population–community level, 2) Biological Vulnerability Index (BVI), assessing the potential threats to biological equilibriums, and 3) Genotoxicity Index (GTI), screening genotoxicity effects. The EDSS has been applied in the integration of a battery of Triad data obtained during the European Union-funded Life Intervention in the Fraschetta Area (LINFA) project, which has been carried out in order to estimate the potential risk from soils of a highly anthropized area (Alessandria, Italy) mainly impacted by deposition of atmospheric pollutants. Results obtained during 4 seasonal sampling campaigns (2004–2005) show maximum values of EnvRI in sites A and B (characterized by industrial releases) and lower levels in site D (affected by vehicular traffic emissions). All 3 potentially polluted sites have shown high levels of BVI and GTI, suggesting a general change from reference conditions (site C).

Globally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air interface across 34 European streams. We directly measured fluxes four times between October 2016 and July 2017 using drifting chambers. Median fluxes are 1.4 and 2.1 mmol m⁻² h⁻¹ at midday and midnight, respectively, with night fluxes exceeding those during the day by 39%. We attribute diel carbon dioxide flux variability mainly to changes in the water partial pressure of carbon dioxide. However, no consistent drivers could be identified across sites. Our findings highlight widespread day-night changes in fluvial carbon dioxide fluxes and suggest that the time of day greatly influences measured carbon dioxide fluxes across European streams.

There is much evidence that climate is rapidly changing at a global scale, especially regarding mean annual temperatures, precipitations and evaporation. The consequences of this rapid environmental change on freshwater biota are still not clear, but undoubtedly they could be severe. Among the main effects of climate change, we can individuate the enhancement of water temperatures, particularly important for poikilothermic organisms, with the consequent diminution of dissolved oxygen, and the reduction of available habitats for most stenothermal organisms. Another consequence of climate change is the alteration of hydrologic cycles, with increasing intensity and frequency of extreme events such as droughts, especially in Southern Europe. This scenario could severely affect freshwater biota, especially in mid-latitude regions, such as the Italian peninsula: shifts in phenology, life cycles and distribution ranges are likely to be expected for many organisms, with the extinction of many sensitive species. In particular, species adapted to perennial and cold waters are likely to suffer reductions in their distribution range and also local extinctions, while more tolerant organisms may enlarge their distribution ranges. Global climate change may also promote and enhance invasions of alien species. In this work, concepts and hypotheses about the presumable impacts of climate change upon freshwater biota are reported, with examples and predictions related to the Italian situation.

In the rivers of northern Italy, the presence of water is typically continuous all year long, although in the last five decades there has been a conspicuous increase in drought periods, mainly caused by human impacts and climate change. The aim of this study was to assess the impact of the length of the drought periods on macroinvertebrate assemblages. We collected invertebrates in four reaches of the Po river, characterised by different periods of absence of surface water. We found significant differences among the stations in invertebrate abundance and taxa richness, with a decrease in the more drought‐affected stream reaches. Collector‐gatherers significantly increased as the drought period lengthened, while the opposite occurred for scrapers and shredders. The areas with a discontinuous presence of water were mainly colonised by small, fast‐growing, plurivoltine organisms. A main result of our study is that only a few taxa appear to be able to survive in reaches with intermittent flow, underlining the great ecological difference between perennial and naturally intermittent streams. Our results suggest that the recent increase of droughts will likely cause an impoverishment of benthic communities in prealpine rivers.