Design-based spatial interpolation with data driven selection of the smoothing parameter

Environmental and Ecological Statistics - In the inverse distance weighting interpolation the interpolated, value is a weighted mean of the sampled values, with weights decreasing with the...     

Biogenic disturbance determines invasion success in a subtidal soft-sediment system

Theoretically, disturbance and diversity can influence the success of invasive colonists if (1) resource limitation is a prime determinant of invasion success and (2) disturbance and diversity affect the availability of required resources. However, resource limitation is not of overriding importance in all systems, as exemplified by marine soft sediments, one of Earth's most widespread habitat types. Here, we tested the disturbance-invasion hypothesis in a marine soft-sediment system by altering rates of biogenic disturbance and tracking the natural colonization of plots by invasive species. Levels of sediment disturbance were controlled by manipulating densities of burrowing spatangoid urchins, the dominant biogenic sediment mixers in the system. Colonization success by two invasive species (a gobiid fish and a semelid bivalve) was greatest in plots with sediment disturbance rates < 500 cm(3) x m(-2) x d(-1), at the low end of the experimental disturbance gradient (0 to > 9000 cm(3) x m(-2) x d(-1)). Invasive colonization declined with increasing levels of sediment disturbance, counter to the disturbance-invasion hypothesis. Increased sediment disturbance by the urchins also reduced the richness and diversity of native macrofauna (particularly small, sedentary, surface feeders), though there was no evidence of increased availability of resources with increased disturbance that would have facilitated invasive colonization: sediment food resources (chlorophyll a and organic matter content) did not increase, and space and access to overlying water were not limited (low invertebrate abundance). Thus, our study revealed the importance of biogenic disturbance in promoting invasion resistance in a marine soft-sediment community, providing further evidence of the valuable role of bioturbation in soft-sediment systems (bioturbation also affects carbon processing, nutrient recycling, oxygen dynamics, benthic community structure, and so on.). Bioturbation rates are influenced by the presence and abundance of large burrowing species (like spatangoid urchins). Therefore, mass mortalities of large bioturbators could inflate invasion risk and alter other aspects of ecosystem performance in marine soft-sediment habitats.     

Population structure of short-beaked common dolphins (<Emphasis Type="Italic">Delphinus delphis</Emphasis>) in the North Atlantic Ocean as revealed by mitochondrial and nuclear genetic markers

The understanding of population structure and gene flow of marine pelagic species is paramount to monitoring, management and conservation studies. Such studies are often hampered by the potentially high dispersal behavior of the species, the lack of obvious geographical barriers in the marine environment and the scarce sample availability. Short-beaked common dolphins (Delphinus delphis) are widespread in coastal and open-ocean habitats of the North Atlantic Ocean, nevertheless population structure and migratory patterns are poorly understood. Furthermore, concern has been raised about the status of the species because large numbers of dolphins have been taken incidentally in several fisheries throughout the North Atlantic in the past decades. In the present study, a large number of individual samples were obtained from seasonal and spatial aggregations of common dolphins from western (wNA) and eastern North Atlantic (eNA) regions, mostly using opportunistic sampling (i.e. from incidental entanglement in fishing gear or beach-cast carcasses). Genetic variability was investigated using nuclear (14 microsatellite loci) and mitochondrial (360 bp of the control region) genetic markers. Levels of genetic diversity were relatively high in all sampled areas and no evidence of recent reduction of effective population size (i.e. bottleneck) was detected at the nuclear loci. Significant population structure was detected between the two main regions (wNA and eNA) where it appeared to be more pronounced at mitochondrial (F _ST = 0.018, P < 0.001) than nuclear markers (F _ST = 0.005, P < 0.05), indicating the presence of at least two genetically distinct populations of common dolphins in the North Atlantic Ocean. In contrast, no significant genetic structure was detected between temporal aggregations of dolphins from within the same region, suggesting possible seasonal movement patterns at a regional scale. The observed levels of genetic differentiation between classes of markers are discussed here as a possible consequence of migratory patterns or recent population subdivision. An erratum to this article can be found at     

Comparison of atmosphere/aquatic environment concentration ratio of volatile chlorinated hydrocarbons between temperate regions and Antarctica

For the purpose of understanding the transport and deposition mechanisms and the air–water distribution of some volatile chlorinated hydrocarbons (VCHCs), their atmosphere/aquatic environment concentration ratio was evaluated. In addition, for the purpose of differentiating VCHC behaviour in a temperate climate from its behaviour in a polar climate, the atmosphere/aquatic environment concentration ratio evaluated in matrices from temperate zones was compared with the concentration ratio evaluated in Antarctic matrices.In order to perform air samplings also at rigid Antarctic temperatures, the sampling apparatus, consisting of a diaphragm pump and canisters, was suitably modified.Chloroform, 1,1,1-trichloroethane, tetrachloromethane, 1,1,2-trichloroethylene and tetrachloroethylene were measured in air, water and snow using specific techniques composed of a purpose-made cryofocusing-trap-injector (for air samples) and a modified purge-and-trap injector (for aqueous samples) coupled to a gas chromatograph with mass spectrometric detection operating in selected ion monitoring mode. The VCHCs were retrieved in all the investigated matrices, both Italian and Antarctic, with concentrations varying from tens to thousands of ng m⁻³ in air and from digits to hundreds of ng kg⁻¹ in water and snow.The atmosphere/aquatic environment concentration ratios were always found to be lower than 1. In particular, the Italian air/water concentration ratios were smaller than the Antarctic ones, by reason of the higher atmospheric photochemical activity in temperate zones. On the other hand, the Antarctic air/snow concentration ratios proved to be largely in favour of snow with respect to the Italian ratios, thus corroborating the hypothesis of a more efficient VCHC deposition mechanism and accumulation on Antarctic snow.     

A Systematic Review of Public Attitudes,Perceptions and Behaviours Towards Production Diseases Associated with Farm Animal Welfare

Increased productivity may have negative impacts on farm animal welfare (FAW) in modern animal production systems. Efficiency gains in production are primarily thought to be due to the intensification of production, and this has been associated with an increased incidence of production diseases, which can negatively impact upon FAW. While there is a considerable body of research into consumer attitudes towards FAW, the extent to which this relates specifically to a reduction in production diseases in intensive systems, and whether the increased incidence of diseases represents a barrier to consumer acceptance of their increased use, requires further investigation. Therefore a systematic review of public attitudes towards FAW was conducted, with a specific focus on production diseases in intensive systems. Four databases were searched to identify relevant studies. A screening process, using a set of pre-determined inclusion criteria, identified 80 studies, with the strength of evidence and uncertainty assessed for each. A thematic analysis led to the identification of 6 overarching themes constructed from 15 subthemes. The results demonstrate that the public are concerned about FAW in modern production systems. Concern varied in relation to age, gender, education and familiarity with farming. Naturalness and humane treatment were central to what was considered good welfare. An evidence gap was highlighted in relation to attitudes towards specific production diseases, with no studies specifically addressing this. However, the prophylactic use of antibiotics was identified as a concern. A number of dissonance strategies were adopted by consumers to enable guilt free meat consumption.     

Combination of beehive matrices analysis and ant biodiversity to study heavy metal pollution impact in a post-mining area (Sardinia, Italy)

Mining activities represent a major source of environment contamination. The aim of this study was to evaluate the use of bees and ants as bioindicators to detect the heavy metal impact in post-mining areas. A biomonitoring programme involving a combination of honeybee hive matrices analysis and ant biodiversity survey was conducted over a 3-year period. The experimental design involved three monitoring stations where repeated sampling activities focused on chemical detection of cadmium (Cd), chrome (Cr) and lead (Pb) from different matrices, both from hosted beehives (foraging bees, honey and pollen) and from the surrounding environment (stream water and soil). At the same time, ant biodiversity (number and abundance of species) was determined through a monitoring programme based on the use of pitfall traps placed in different habitats inside each mining site. The heavy metal content detected in stream water from the control station was always below the analytical limit of quantification. In the case of soil, the content of Cd and Pb from the control was lower than that of mining sites. The mean heavy metal concentrations in beehive matrices from mining sites were mainly higher than the control, and as a result of regression and discriminant analysis, forager bee sampling was an efficient environmental pollution bioindicator. Ant collection and identification highlighted a wide species variety with differences among habitats mostly associated with vegetation features. A lower variability was observed in the polluted landfill characterised by lack of vegetation. Combined biomonitoring with forager bees and ants represents a reliable tool for heavy metal environmental impact studies.     

Biochemical modifications in Pinus pinaster Ait. as a result of environmental pollution

Exposure to chemical pollution can cause significant damage to plants by imposing conditions of oxidative stress. Plants combat oxidative stress by inducing antioxidant metabolites, enzymatic scavengers of activated oxygen and heat shock proteins. The accumulation of these proteins, in particular heat shock protein 70 and heme oxygenase, is correlated with the acquisition of thermal and chemical adaptations and protection against oxidative stress. In this study, we used Pinus pinaster Ait. collected in the areas of Priolo and Aci Castello representing sites with elevated pollution and reference conditions, respectively. The presence of heavy metals and the levels of markers of oxidative stress (lipid hydroperoxide levels, thiol groups, superoxide dismutase activity and expression of heat shock protein 70, heme oxygenase and superoxide dismutase) were evaluated, and we measured in field-collected needles the response to environmental pollution. P. pinaster Ait. collected from a site characterized by industrial pollution including heavy metals had elevated stress response as indicated by significantly elevated lipid hydroperoxide levels and decreased thiol groups. In particular, we observed that following a chronic chemical exposure, P. pinaster Ait. showed significantly increased expression of heat shock protein 70, heme oxygenase and superoxide dismutase. This increased expression may have protective effects against oxidative stress and represents an adaptative cellular defence mechanism. These results suggest that evaluation of heme oxygenase, heat shock protein 70 and superoxide dismutase expression in P. pinaster Ait. could represent a useful tool for monitoring environmental contamination of a region and to better understand mechanisms involved in plant defence and stress tolerance.     

Using phytoremediation technologies to upgrade waste water treatment in Europe

Goal, Scope and Background One of the burning problems of our industrial society is the high consumption of water and the high demand for clean drinking water. Numerous approaches have been taken to reduce water consumption, but in the long run it seems only possible to recycle waste water into high quality water. It seems timely to discuss alternative water remediation technologies that are fit for industrial as well as less developed countries to ensure a high quality of drinking water throughout Europe. Main Features The present paper discusses a range of phytoremediation technologies to be applied in a modular approach to integrate and improve the performance of existing wastewater treatment, especially towards the emerging micro pollutants, i.e. organic chemicals and pharmaceuticals. This topic is of global relevance for the EU. Results Existing technologies for waste water treatment do not sufficiently address increasing pollution situation, especially with the growing use of organic pollutants in the private household and health sector. Although some crude chemical approaches exist, such as advanced oxidation steps, most waste water treatment plants will not be able to adopt them. The same is true for membrane technologies. Discussion Incredible progress has been made during recent years, thus providing us with membranes of longevity and stability and, at the same time, high filtration capacity. However, these systems are expensive and delicate in operation, so that the majority of communities will not be able to afford them. Combinations of different phytoremediation technologies seem to be most promising to solve this burning problem. Conclusions To quantify the occurrence and the distribution of micropollutants, to evaluate their effects, and to prevent them from passing through wastewater collection and treatment systems into rivers, lakes and ground water bodies represents an urgent task for applied environmental sciences in the coming years. Recommendations Public acceptance of green technologies is generally higher than that of industrial processes. The EU should stimulate research to upgrade existing waste water treatment by implementing phytoremediation modules and demonstrating their reliability to the public.     

A biological method to monitor early effects of the air pollution caused by the industrial exploitation of geothermal energy

The suitability of a set of ecophysiological parameters, to be used as early warning indicator to detect signs of a worsening environment around geothermal power plants, was tested by comparison with the diversity of epiphytic lichens, a well-established indicator of geothermal air pollution. Samples of the lichen Evernia prunastri were transplanted around a geothermal power plant at Larderello (Tuscany, Italy) and at a control site, and integrity of cell membranes, concentration of chlorophyll a, b and carotenoids, chlorophyll integrity and variations in pH of thalli were measured. The results showed that cell membrane damage, expressed by changes in electrical conductivity, could be used to detect early (exposure periods as short as 1 month) deleterious effects of geothermal air pollution.     

Field derived accumulation and release kinetics of DDTs in plants

Vegetation plays an important role in influencing the air/surface exchange of semivolatile organic compounds (SOCs). In order to predict the capability of different plant species to capture chemicals from the air, plant-air partition coefficients and kinetic accumulation parameters must be defined. In this study, potted plants of three different species were transferred to the vicinity of a source point for DDT, namely a contaminated area around a former production plant in Italy. Leaves were constantly sampled in order to follow the uptake from air over time. Later, the potted plants were transported to a location characterized by background diffuse air concentrations for the release phase. Coupling the experimental results with a two-compartment accumulation model it was possible to derive the kinetics parameters and the plant-air partition coefficient K(PA) for p,p'-DDT. The logK(PA) (on a mass/volume basis) ranged between 1.7 and 2.2 for the different species. The uncertainties related to the different phenomena involved in a field uptake/release experiment are discussed.