Effect of compost and manure amendments on zinc soil speciation, plant content, and translocation in an artificially contaminated soil

The addition of organic matter in soil can modify the bioavailability of heavy metals. A greenhouse pot experiment was carried out using an edible plant species Eruca vesicaria L. Cavalieri grown on an artificially contaminated soil with Zn (665 mg?kg^?1). In this study, the effect of compost at 20 t?ha^?1 (C20) and at 60 t?ha^?1 (C60), manure at 10 t?ha^?1 (M10) and at 30 t?ha^?1 (M30), and chemical fertilizers (NPK) on Zn fate in a soil–plant system was evaluated. At the end of the experiment, the main growth parameters and Zn content in plants were determined. In addition, Zn speciation in the soil was assessed using the original Community Bureau of Reference sequential extraction and diethylene triamine pentaacetic acid extraction. Zinc, though an essential element for plant growth, caused toxicity effects in plants grown on control and manure treatments, while in the compost treatments, plants showed no visual toxicity symptoms. The concentrations of Zn in roots were similar for all treatments, while significant differences were observed for shoots. In fact, in the compost treatments, plants showed the lowest Zn concentration in shoots. Zinc speciation seems not to be affected by the applied treatments. Indeed, Zn plant content and translocation to shoots seems to be affected. Compost amendments significantly reduced Zn content and translocation in comparison to other treatments.     

Spectral trend of vegetation with rainfall in events of El Niño-Southern Oscillation for Atlantic Forest biome,Brazil

This study aimed to analyze the spectral trend of vegetation with rainfall in El Niño-Southern Oscillation events (ENSO) in the Atlantic Forest, Brazil. Monthly rainfall data were collected from 85 conventional meteorological stations (EMC), data from the Enhanced Vegetation Index 2 (EVI2) and ENSO events (El Niño, La Niña, and Neutral) in the period from 2001 to 2013. Afterwards, state cluster analysis was performed using the results of non-parametric tests. The Mann-Kendall (MK) non-parametric test did not identify a trend pattern in rainfall distribution in the Atlantic Forest. The results for EVI2 by state and region showed that the trend is decreasing in the Northeast Region, except for the states of Alagoas and Pernambuco. Southeast region showed an increasing trend of EVI2 (except for Rio de Janeiro and São Paulo), while the South region showed a decreasing trend. In the Midwest, the trend was significantly decreasing. In the prognosis elaborated for the future, the regions with significant declines of the vegetation were the Northeast and Midwest. This study shows that the Atlantic Forest in some regions of Brazil has been suffering from the growing urbanization process and there is a trend of soil degradation.     

Morphological and statistical analysis of the impact of breakwaters under construction on a sand spit area (Douro River estuary)

The area of Cabedelo sand spit, located at the mouth of Douro River estuary (Porto, Portugal), reduced in recent decades. In order to study its evolution and also the impact of two breakwaters built to fix the river entrance, a dataset from 23 trimestral surveys using differential GPS techniques, conducted between 2001 and 2007, were considered. A time-series analysis and the estimation of relationships between Cabedelo spit area and several hydrodynamic parameters through statistical techniques were performed in order to determine which parameters have more influence in the Cabedelo spit behavior. From the time-series analysis a seasonal tendency is visible, with the lower values occurring in December and the higher values occurring in July. The estimation of a relationship between Cabedelo spit area and several independent variables reached better results when the dataset was divided in Part A (before the beginning of breakwaters construction) and Part B (during the breakwaters construction). An analysis of the morphological evolution of Cabedelo spit shoreline was also performed: (1) a simple analysis of retreat and accretion rates data with a geographical information system and (2) a more exhaustive analysis were performed using Empirical Orthogonal Functions (EOFs). The Cabedelo spit shoreline erosion occurs mostly on the West and North side, and the accretion mostly occurs in the area protected by the South breakwater. During the breakwater’s construction, the Cabedelo spit shoreline presented high retreat rates, with a mean value greater than 100 m. In terms of spatial variance (EOFs analysis), when the dataset was divided in two parts, the first Principal Component (PC) represents 60.10 % and 89.86 % of the mean squared value of the data, for Part A and Part B, respectively. As proved, the breakwaters would tend to stabilize the coastline leading to a higher first PC value after breakwaters construction (Part B).     

Measuring sustainable development knowledge,attitudes, and behaviors: evidence from university students in Mexico

Environment, Development and Sustainability - Current trends such as imminent overpopulation and the take-make-waste economic model are largely responsible for the planet’s dire situation....     

Exploring management strategies for community-based forests using multi-agent systems: A case study in Palawan, Philippines

This paper describes the experiences and lessons learned in applying a multi-agent systems (MAS) model to study the dynamics and complex interactions among stakeholders in the management of community-based forests. The MAS model is developed using the companion modelling (ComMod) approach, which allows for a collaborative development of the model between the stakeholders and researchers. This approach involves the development and application of role-playing games (RPGs) and computer simulation as learning tools and to validate the model. Inferences are drawn from the learning and negotiation processes that the stakeholders and researchers underwent in the collaborative development of the MAS model. These processes ultimately led to the development of a collaborative resource management plan. The approach and the MAS model were applied to a case study involving a community-based forest managed by three villages in the island of Palawan, Philippines.     

Characterization of water extractable organic matter in a deep soil profile

The aim of this study was to identify qualitative and quantitative differences of water extractable organic matter (WEOM) isolated from each horizon along a deep soil profile and to evaluate any relationship between the WEOC and the total organic carbon (TOC) content. The soil profile "Monte Pietroso" is located in the Murge area, Apulia region in Southern Italy. Samples from the eight horizons (Ap1, Ap2, Ab1, Ab2, Bt1, 2B, 2Bt2, and 2B/C) were collected in October 2002. The WEOM characterization was carried out by means of UV absorbance, fluorescence spectroscopy in the emission and excitation/emission matrix (EEM) modes, and additional spectroscopic derived indexes. Soil organic carbon was shown to accumulate in the top horizons (Ap) and, in general, to decrease with depth, whereas, the WEOM/TOC ratio increases with increasing depth. The aromaticity and the humification index of the WEOM decrease dramatically downward the soil profile, whereas the fluorescence efficiency index tends to increase markedly. The WEOM fractions feature three main fluorophores with different wavelength and relative intensity. In general WEOM transport phenomena are suggested to occur downward the soil profile, depending on the nature of the organic material and on the chemical and mineral characteristics of the various horizons.     

Response of Holm oak (Quercus ilex subsp. ballota) and mastic shrub (Pistacia lentiscus L.) seedlings to high concentrations of Cd and Tl in the rhizosphere

The impairment of root growth and photosynthetical functioning are the main impacts of trace elements on woody plant seedlings. In this work, we assessed the response of Holm oak (Quercusilex subsp. ballota) and mastic shrub (Pistacia lentiscus) seedlings to high concentrations of Cd and Tl in the rhizosphere. These are non-essential trace elements, with a potential high mobility in the soil-plant system. Seedlings of these species are frequently used in the afforestation of degraded soils in mining areas. Plants were exposed to different levels of Cd (20, 80 and 200 mg L⁻¹) and Tl (2, 10 and 20 mg L⁻¹) in a sand culture. Biomass allocation, growth rates, chlorophyll fluorescence and gas exchange were studied. Both metals affected root biomass. Cadmium produced an increase in the root mass ratio and a decrease in the specific leaf area of the plants in oak seedlings, while Tl did not provoke such response. Mastic plants were more sensitive to Tl and Cd than oak plants. Between elements, Tl provoked more severe toxic effects in the plants, affecting the antennae complexes and reaction centers of the photosystem II. Both elements decreased net assimilation rates (down to a 20% of the control plants) and stomatal conductance (5-10% of the values for the control plants). Cadmium was highly retained in the roots of both species, while Tl was highly translocated into the leaves. In general, Holm oak showed a higher tolerance for Cd than for Tl, and a higher resistance to both metals than mastic shrub, due to a high capacity for Cd retention at the root level. However, such accumulation in roots may induce water stress in the seedling exposed to Cd.     

Removal of 17α-ethinylestradiol from a sterile WC medium by the cyanobacteria Microcystis novacekii

An unprecedented investigation dealing with the removal of 17α-ethinylestradiol (EE2, a contraceptive hormone) by the cyanobacteria Microcystis novacekii (a species that is abundant and easily accessible in Brazilian lakes) from a sterile WC medium is described herein. The results indicated that whereas EE2 experienced insignificant spontaneous degradation, Microcystis novacekii was capable of removing ca. 65% of the hormone from the culture medium. Furthermore, no metabolites were detected at the concentration levels evaluated (0.10 to 0.17 mg L(-1)) as verified by the use of GC-MS, a quite sensitive analytical technique, and adequate pre-concentration procedures (SPME and liquid extraction). Elucidative experiments, including an appropriate cell lyses procedure, indicated that EE2 was likely accumulated within the cells (bioaccumulation) rather than adsorbed on the cellular membrane (biosorption). Moreover, the intra- and extracellular contents of EE2 were shown to be roughly complementary. Finally, the species was found to be highly tolerant to the hormone as its growth rates were higher in the test than in the control experiments. All these findings, therefore, point to the use of Microcystis novacekii as a potential agent to treat effluents contaminated with EE2.     

Monitoring of Cr, Cu, Pb, V and Zn in polluted soils by laser induced breakdown spectroscopy (LIBS)

Laser Induced Breakdown Spectroscopy (LIBS) is a fast and multi-elemental analytical technique particularly suitable for the qualitative and quantitative analysis of heavy metals in solid samples, including environmental ones. Although LIBS is often recognised in the literature as a well-established analytical technique, results about quantitative analysis of elements in chemically complex matrices such as soils are quite contrasting. In this work, soil samples of various origins have been analyzed by LIBS and data compared to those obtained by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). The emission intensities of one selected line for each of the five analytes (i.e., Cr, Cu, Pb, V, and Zn) were normalized to the background signal, and plotted as a function of the concentration values previously determined by ICP-OES. Data showed a good linearity for all calibration lines drawn, and the correlation between ICP-OES and LIBS was confirmed by the satisfactory agreement obtained between the corresponding values. Consequently, LIBS method can be used at least for metal monitoring in soils. In this respect, a simple method for the estimation of the soil pollution degree by heavy metals, based on the determination of an anthropogenic index, was proposed and determined for Cr and Zn.