Great spotted cuckoo fledglings are disadvantaged by magpie host parents when reared together with magpie nestlings

The post-fledging period is a critical phase for juvenile survival, and parental care provided during this period is a key component of avian reproductive performance. Very little is known about the relationships between foster parents and fledglings of brood parasites. Here, we present the results of a 5-year study about the relationships between fledglings of the non-evictor brood parasitic great spotted cuckoo (Clamator glandarius) and its magpie (Pica pica) foster parents. Sometimes, great spotted cuckoo and magpie nestlings from the same nest can fledge successfully, but most often parasitic nestlings outcompete host nestlings and only cuckoos leave the nest. We have studied several aspects of cuckoo post-fledging performance (i.e. feeding behaviour, parental defence and fledgling survival) in experimental nests in which only cuckoos or both magpie and cuckoo nestlings survived until leaving the nest. The results indicate that great spotted cuckoo fledglings reared in mixed broods together with magpie nestlings were disadvantaged by magpie adults with respect to feeding patterns. Fledgling cuckoos reared in mixed broods were fed less frequently than those reared in only cuckoo broods, and magpie adults approached less frequently to feed cuckoos from mixed broods than cuckoos from only cuckoo broods. These results imply that the presence of host's own nestlings for comparison may be a crucial clue favouring the evolution of fledgling discrimination; and furthermore, that the risk of discrimination at the fledgling stage probably is an important selection pressure driving the evolution of the arms race between brood parasites and their hosts.     

Evaluating the Environmental Performance of Urban Parks in Mediterranean Cities: An Example from the Barcelona Metropolitan Region

In a context of increasing urban sprawl and water scarcity common to other Mediterranean cities, this article focuses on the urban parks in the Region of Barcelona (Catalonia, Spain) to examine how these parks are distributed in this region and to assess whether their design and management follow criteria adapted to Mediterranean environmental conditions, especially in what concerns water use. In order to evaluate the environmental performance of these parks, we selected four factors possibly influencing the adoption of park management practices at the local scale: urban density, population size of the municipality, municipal income per capita, and political orientation of the city council. After determining the location and area of urban parks in the region, we correlated these four explanatory factors with several management tasks extracted from two different samples of parks (one of 315 parks and another of 125 parks) and a survey of 86 city councils. Results show that, in general, urban parks were more frequent in large, dense, and left/green municipalities but that environmentally sound practices were more common in small and low-density municipalities. We conclude that changes in certain practices (especially the substitution of high water demanding species) could improve significantly the environmental performance of public spaces in large urban areas with Mediterranean climates. Our observations may be pertinent for other cities interested in the provision of environmental public goods such as parks that necessitate water for irrigation.     

Orchard management under the effects of climate change: implications for apple,plum, and almond growing

Environmental Science and Pollution Research - The authors analyzed certain species and varieties of fruit tree in which applied crop technology is used and also undergoes the effects of climate...     

Green Synthesis of Silver Nanoparticles and Study of Their Antimicrobial Properties

One of the major disadvantages of polymers when used in food-contact applications is that they are very susceptible to microbial attack. On the other hand, silver nanoparticles have received increased attention as novel antimicrobial agents. Therefore, the introduction of silver nanoparticles into conventional polymers results in new materials with improved properties. In this investigation, colloidal silver nanoparticles using an environmentally friendly procedure were synthesized. An aqueous solution of AgNO₃ was used as a silver precursor with ‘green’ reducing agents either different types of honey, or β-d-glucose. In the first case, different pH values, as well as the addition of poly(ethylene glycol), PEG were studied, while in the latter, the effect of reduction time in the presence of PEG with various average molecular weights was examined. Properties of the nanoparticles were measured using X-Ray diffraction, UV–Vis and FTIR spectroscopy. Using honey it seems that spherical particles are produced with the smaller average particle size obtained at pH 8.5. Use of honey has the advantage of being a natural product, although its main drawback is that its composition varies and it cannot be predefined to result in reproducible results. Use of β-d-glucose results in stable silver nanoparticles with small average particle size after 24 h reduction. The addition of low molecular weight PEG seems to be beneficial in the production of stable nanoparticles. Finally, the antimicrobial activity of the nanoparticles produced was investigated at different concentrations on both Gram positive and negative bacteria, such as Bacillus cereus, Bacillus subtilis, Escherichia coli and Staphylococcus aureus.     

An experimental design for the optimization of the extraction methods of metallic mobile fractions from environmental solid samples

The evaluation of the cadmium and lead mobile forms from environmental solid samples provides information about their mobility and bioavailability. In the present study, the Cd and Pb mobile fractions were obtained by two modified extraction methods applied to industrial and acidic pH soils or to polluted sediments. In order to highlight that the extraction procedure does not significantly influence the quantitative atomic absorption spectrometric determination of cadmium and lead, the robustness of the extraction methods was evaluated and proven applying a Youden and Steiner factorial design. Within this experimental design, the shaking rate, the shaking time, and the solid/liquid extraction ratio were modified. The measurement uncertainty of the whole analytical procedure was assessed, the contribution of the factors involved in the extraction process being insignificant compared to the other uncertainty sources. The importance of the study is related to the fact that it proves the applicability in the routine laboratory practice of the modified extraction methods by increasing the extraction ratio following thorough optimization and robustness studies.     

Residual Effect of Induced Water Stress and Nitrogen Addition on the Mycobiota in Scots Pine Stands

Mycobiota (fungi, lichens and myxomycetes) was examined in permanent plots following experiments of artificial drought (D) and nitrogen addition (N) and compared with untreated forest (C), in Scots pine stand planted on Arenosols. Species diversity and relationships between fungal community structure and environmental variables (plant species numbers and cover, bryophyte cover, soil and bark pH, tree mortality) were explored. Both D and N treatments lead to decrease of fungal species in general, however, responses of individual trophic and ecological groups varied. The strongest effect of the treatments was observed for soil fungi, especially mycorrhizal: numbers of fruiting species and ectomycorrhizal root tips decreased, and species composition has changed. Saprotrophic fungi reacted by changes in species composition but not in numbers. Of the studied environmental variables, the most significant effect on mycobiota had bryophyte and vascular plant cover as well as vascular plant species numbers.     

Constructing herbicide metribuzin sustained-release formulations based on the natural polymer poly-3-hydroxybutyrate as a degradable matrix

Polymer poly(3-hydroxybutyrate) [P(3HB)] has been used as a matrix in slow-release formulations of the herbicide metribuzin (MET). Physical P(3HB)/MET mixtures in the form of solutions, powders, and emulsions were used to construct different metribuzin formulations (films, granules, pellets, and microparticles). SEM, X-Ray, and DSC proved the stability of these formulations incubated in sterile water in vitro for long periods of time (up to 49 days). Metribuzin release from the polymer matrix has been also studied. By varying the shape of formulations (microparticles, granules, films, and pellets), we were able to control the release time of metribuzin, increasing or decreasing it.     

Applying the Ecosystem Approach to Select Priority Areas for Forest Landscape Restoration in the Yungas, Northwestern Argentina

This paper proposes a method to select forest restoration priority areas consistently with the key principles of the Ecosystem Approach (EA) and the Forest Landscape Restoration (FLR) framework. The methodology is based on the principles shared by the two approaches: acting at ecosystem scale, involving stakeholders, and evaluating alternatives. It proposes the involvement of social actors which have a stake in forest management through multicriteria analysis sessions aimed at identifying the most suitable forest restoration intervention. The method was applied to a study area in the native forests of Northern Argentina (the Yungas). Stakeholders were asked to identify alternative restoration actions, i.e. potential areas implementing FLR. Ten alternative fincas—estates derived from the Spanish land tenure system—differing in relation to ownership, management, land use, land tenure, and size were evaluated. Twenty criteria were selected and classified into four groups: biophysical, social, economic and political. Finca Ledesma was the closest to the economic, social, environmental and political goals, according to the values and views of the actors involved in the decision. This study represented the first attempt to apply EA principles to forest restoration at landscape scale in the Yungas region. The benefits obtained by the application of the method were twofold: on one hand, researchers and local actors were forced to conceive the Yungas as a complex net of rights rather than as a sum of personal interests. On the other hand, the participatory multicriteria approach provided a structured process for collective decision-making in an area where it has never been implemented.     

Pd-Fe nanoparticles stabilized by chitosan derivatives for perchloroethene dechlorination

A series of chitosan-stabilized Pd-NZVI (nano-zero-valent-iron) catalysts for dechlorination with variation in their composition and in the nature of the polymer has been prepared. The synthesis procedures and palladium and chitosan contents were optimized. It was demonstrated by the XPS method that Fe and Pd in Fe-Pd/chitosan samples exist in the metallic state. The positive shift of the binding energy as compared with the bulk metal shows that the iron metal in the surface layers exists as very small nanoparticles. The prepared materials were characterized also by the XAS method. The presence of O and N atoms in the first coordination shell of the central Fe atom in the Fe-Pd/chitosan samples certifies the binding of the Fe metal particles with the chitosan surface via OH and NH(2) groups. The samples are characterized by the high stability of the nanoparticles as compared to unstabilized Pd-NZVI. The materials were tested to evaluate their catalytic activity in the perchloroethene (PCE) dechlorination reaction. Some samples of chitosan-stabilized Pd-NZVI revealed a good performance in PCE degradation as compared to unstabilized Pd-NZVI.     

PCDD/Fs in ambient air in north-east Italy: The role of a MSWI inside an industrial area

The stack gases of a municipal solid waste incinerator (MSWI), and ambient air were sampled in four locations around the plant for the analysis of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs). The sampling area was close to an industrial area near Trieste, in north-east Italy. The purpose of the study was to estimate the impact of the MSWI emissions and to distinguish the contribution of these emissions from other potential emission sources in the industrial area.PCDD/F atmospheric concentrations were similar to those generally detected in urban–rural areas with one location about 2–3 times more contaminated than the others. Since the most contaminated location was inside the industrial area but upwind of the MSWI, principal component analysis (PCA) was used to establish whether other sources were the cause. This analysis clearly showed that a local steel plant’s emission was the main source of PCDDs/Fs in ambient air. This study highlights the usefulness of multivariate data analysis such as PCA to identify, among different potential emission sources, the one really responsible for the contamination.