Pollination syndromes ignored: importance of non-ornithophilous flowers to Neotropical savanna hummingbirds

Generalization prevails in flower–animal interactions, and although animal visitors are not equally effective pollinators, most interactions likely represent an important energy intake for the animal visitor. Hummingbirds are nectar-feeding specialists, and many tropical plants are specialized toward hummingbird-pollination. In spite of this, especially in dry and seasonal tropical habitats, hummingbirds may often rely on non-ornithophilous plants to meet their energy requirements. However, quantitative studies evaluating the relative importance of ornithophilous vs. non-ornithophilous plants for hummingbirds in these areas are scarce. We here studied the availability and use of floral resources by hummingbirds in two different areas of the Cerrado, the seasonal savannas in Central Brazil. Roughly half the hummingbird visited plant species were non-ornithophilous, and these contributed greatly to increase the overall nectar availability. We showed that mean nectar offer, at the transect scale, was the only parameter related to hummingbird visitation frequency, more so than nectar offer at single flowers and at the plant scale, or pollination syndrome. Centrality indices, calculated using hummingbird–plant networks, showed that ornithophilous and non-ornithophilous plants have similar importance for network cohesion. How this foraging behaviour affects reproduction of non-ornithophilous plants remains largely unexplored and is probably case specific, however, we suggest that the additional energy provided by non-ornithophilous plants may facilitate reproduction of truly ornithophilous flowers by attracting and maintaining hummingbirds in the area. This may promote asymmetric hummingbird–plant associations, i.e., pollination depends on floral traits adapted to hummingbird morphology, but hummingbird visitation is determined more by the energetic "reward" than by pollination syndromes.     

Quantitative–spatial assessment of soil contamination in S. Francisco de Assis due to mining activity of the Panasqueira mine (Portugal)

Through the years, mining and beneficiation processes produces large amounts of As-rich mine wastes laid up in huge tailings and open-air impoundments (Barroca Grande and Rio tailings) that are the main source of pollution in the surrounding area once they are exposed to the weathering conditions leading to the formation of AMD and consequently to the contamination of the surrounding environments, in particularly soils. In order to investigate the environmental contamination impact on S. Francisco de Assis (village located between the two major impoundments and tailings) agricultural soils, a geochemical survey was undertaken to assess toxic metals associations, related levels and their spatial distribution, and to identify the possible contamination sources. According to the calculated contamination factor, As and Zn have a very high contamination factor giving rise to 65.4 % of samples with a moderate to high pollution degree; 34.6 % have been classified as nil to very low pollution degree. The contamination factor spatial distribution put in evidence the fact that As, Cd, Cu, Pb, and Zn soils contents, downstream Barroca Grande tailing, are increased when compared with the local Bk soils. The mechanical dispersion, due to erosion, is the main contamination source. The chemical extraction demonstrates that the trace metals distribution and accumulation in S. Francisco de Assis soils is related to sulfides, but also to amorphous or poorly crystalline iron oxide phases. The partitioning study allowed understanding the local chemical elements mobility and precipitation processes, giving rise to the contamination dispersion model of the study area. The wind and hydrological factors are responsible for the chemical elements transport mechanisms, the water being the main transporter medium and soils as one of the possible retention media.     

Atmospheric composition change research: Time to go post-normal?

For more than two decades a number of frameworks for scientific knowledge production are being proposed by science and technology researchers. They all advocate an extended involvement of non-specialists, in particular when it comes to knowledge production applicable to practical societal problems. We look to what extent these new frameworks have taken ground within a particular research community: the ACCENT Network of Excellence which coordinates European atmospheric chemistry and physics research applicable to air pollution and climate change. We did so by stimulating a debate through a “blog”, a survey and in-depth interviews with ACCENT scientists about the interaction between science, policy making and civil society, to which a great deal of ACCENT member contributed in writing or verbally. Most of them had interactions with policy makers and/or the general public, and they generally believe that interactions with spheres other than the scientific are needed. While such interactions give personal insight and satisfaction, they seem to have little impact on the goals and the practice of the scientific work itself. Extended frameworks of science production that go beyond the disciplinary mode seem to emerge at the level of individual scientists, yet they still need to find their way to the level of scientific project management. In this paper we discuss the justifications and barriers to implement a higher degree of extended knowledge integration in applied science projects such as ACCENT. It is felt that the community of atmospheric chemists and physicists is mature for such an implementation and recommendations are given to help and make this happen.     

Metal fractionation of cadmium, lead and arsenic of geogenic origin in topsoils from the Marrancos gold mineralisation, northern Portugal

The Marrancos gold mineralisation has a chemical assemblage of Fe–As–Se–Bi–Au–Ag–Te–(Cu–Pb–Zn–Sn–W). The −200 mesh of 144 topsoil samples was analysed by ICP–MS to determine total contents of 53 elements that include potentially harmful elements like Cd, As and Pb. The soil geochemistry shows that some trace elements occur in considerably high concentrations. On the basis of data for total metal concentrations, 10 topsoil samples were selected to carry out a metal fractionation study using a selective extraction method. A set of four leaches of increasing strength was used sequentially in the soil samples. Across the study area, there is some evidence of past mining and exploration activity, indicating that these soils may be locally disturbed. The shallow mineralised quartz veins were exploited for gold by the Romans. Several galleries were constructed during the 2nd World War, probably for the exploration of quartz–cassiterite–wolframite veins. However, the main mineralised body in depth was never explored. The results of metal fractionation show different partitions for the three elements. Total Cd concentrations in these soils are low, with a median value of 0.1 mg/kg. In average, 12% of total Cd is adsorbed by clays and/or co-precipitated with carbonates, and 19% is bounded to Fe–Mn oxyhydroxides. However, the low concentrations indicate that the metal does not represent an immediate risk to human health. For Pb, metal fractionation shows that, on average, 22% of Pb is adsorbed by amorphous Fe and Mn oxides, but the samples from the northern part of the area have the major fractions of Pb in soluble forms. The low probability of exposure in this part of the study area decreases the risk posed by this heavy metal. Total As concentrations in the Marrancos soils are extremely high. A large area has As concentrations above 1,000 mg/kg. For As, metal fractions in the sulphide phase vary between 84 and 98% in the studied samples. But one sample has 20% of total As in easily reducible forms, corresponding to a partial concentration of 1,800 mg/kg that has a high probability of being bioavailable. The most labile As forms occur at the southern part of the area, where the probability of exposure is higher and the risk of human health increases in the same order. From the three studied potentially harmful elements, As is certainly the element of concern.     

Mg-Fe layered double hydroxide with chloride intercalated: synthesis,characterization and application for efficient nitrate removal

Environmental Science and Pollution Research - Mg-Fe layered double hydroxide intercalated with chloride (Mg-Fe-Cl LDH) was synthetized, characterized, and evaluated as adsorbent to remove nitrate...     

Bio-based films/nanopapers from lignocellulosic wastes for production of added-value micro-/nanomaterials

Environmental Science and Pollution Research - The growing demand for products with lower environmental impact and the extensive applicability of cellulose nanofibrils (CNFs) have received...     

Insights into PU/EVA Blends Produced Using Industrial Residues Towards Eco-efficient Materials

Journal of Polymers and the Environment - Aiming at minimizing the issues associated with the disposal of polymers, in this study, elastomeric materials derived from 100% recycled feedstocks were...     

Assessment of Eutrophication in Estuaries: Pressure–State–Response and Nitrogen Source Apportionment

A eutrophication assessment method was developed as part of the National Estuarine Eutrophication Assessment (NEEA) Program. The program is designed to improve monitoring and assessment of eutrophication in the estuaries and coastal bays of the United States with the intent to guide management plans and develop analytical and research models and tools for managers. These tools will help guide and improve management success for estuaries and coastal resources. The assessment method, a Pressure-State-Response approach, uses a simple model to determine Pressure and statistical criteria for indicator variables (where applicable) to determine State. The Response determination is mostly heuristic, although research models are being developed to improve that component. The three components are determined individually and then combined into a single rating. Application to several systems in the European Union (E.U.), specifically in Portugal, shows that the method is transferable, and thus is useful for development of management measures in both the Unites States and E.U. This approach identifies and quantifies the key anthropogenic nutrient input sources to estuaries so that management measures can target inputs for maximum effect. Because nitrogen is often the limiting nutrient in estuarine systems, examples of source identification and quantification for nitrogen have been developed for 11 coastal watersheds on the U.S. east coast using the WATERSN model. In general, estuaries in the Northeastern United States receive most of their nitrogen from human sewage, followed by atmospheric deposition. This is in contrast to some watersheds in the Mid-Atlantic (Chesapeake Bay) and South Atlantic (Pamlico Sound), which receive most of their nitrogen from agricultural runoff. Source identification is important for implementing effective management measures that should be monitored for success using assessment methods, as described herein. For instance, these results suggest that Northeastern estuaries would likely benefit most from improved sewage treatment, where as the Mid and South Atlantic systems would benefit most from agricultural runoff reductions.     

Evaluation of copper effects upon Girardia tigrina freshwater planarians based on a set of biomarkers

Copper is a common environmental contaminant, which is particularly toxic to living organisms when in high concentrations. To monitor environmental contamination by Cu2+ and other heavy metals, well characterized bioindicator organisms and standardized assays are needed. As a first step toward this end, we have analysed Cu2+ effects upon Girardia tigrina freshwater planarians, based on the assessment of mobility, regeneration performance, micronucleus (MN) frequency in regenerating animals, and reproductive performance. These four biomarkers provided complementary information on Cu2+ toxicity, teratogenicity, mutagenicity and chronic (>96 h of exposure) effects, respectively. The LC50 was calculated for newborn, adult and regenerating planarians, and values of 12+/-0.02 mg l(-1), 42+/-0.08 mg l(-1), 48+/-0.13 mg l(-1), respectively, were obtained after 96 h of exposure. Mobility, for intact adults, and time of regeneration and MN frequency, for regenerating animals, were significantly affected by Cu2+ concentrations as low as 0.10 mg l(-1). MN assay for regenerating G. tigrina neoblasts showed higher sensitivities than MN assays performed with other bioindicator freshwater organisms, such as moluscs or fish. Chronic exposure effects were clearly evidenced by assessment of reproductive performance, with significant reduction in fecundity and fertility rates upon exposure to Cu2+ concentrations as low as 0.05 mg l(-1). Therefore, G. tigrina can be regarded as a useful bioindicator species for the detection and evaluation of Cu2+ effects upon freshwater invertebrates, allowing insights on the effects of Cu2+ (and possibly other heavy metals) in a freshwater environment.