Modelling the Ecological Vulnerability to Forest Fires in Mediterranean Ecosystems Using Geographic Information Technologies

Forest fires represent a major driver of change at the ecosystem and landscape levels in the Mediterranean region. Environmental features and vegetation are key factors to estimate the ecological vulnerability to fire; defined as the degree to which an ecosystem is susceptible to, and unable to cope with, adverse effects of fire (provided a fire occurs). Given the predicted climatic changes for the region, it is urgent to validate spatially explicit tools for assessing this vulnerability in order to support the design of new fire prevention and restoration strategies. This work presents an innovative GIS-based modelling approach to evaluate the ecological vulnerability to fire of an ecosystem, considering its main components (soil and vegetation) and different time scales. The evaluation was structured in three stages: short-term (focussed on soil degradation risk), medium-term (focussed on changes in vegetation), and coupling of the short- and medium-term vulnerabilities. The model was implemented in two regions: Aragón (inland North-eastern Spain) and Valencia (eastern Spain). Maps of the ecological vulnerability to fire were produced at a regional scale. We partially validated the model in a study site combining two complementary approaches that focused on testing the adequacy of model’s predictions in three ecosystems, all very common in fire-prone landscapes of eastern Spain: two shrublands and a pine forest. Both approaches were based on the comparison of model’s predictions with values of NDVI (Normalized Difference Vegetation Index), which is considered a good proxy for green biomass. Both methods showed that the model’s performance is satisfactory when applied to the three selected vegetation types.     

High throughput and miniaturised systems for biodegradability assessments

The society demands safer products with a better ecological profile. Regulatory criteria have been developed to prevent risks for human health and the environment, for example, within the framework of the European regulation REACH (Regulation (EC) No 1907, 2006). This has driven industry to consider the development of high throughput screening methodologies for assessing chemical biodegradability. These new screening methodologies must be scalable for miniaturisation, reproducible and as reliable as existing procedures for enhanced biodegradability assessment. Here, we evaluate two alternative systems that can be scaled for high throughput screening and conveniently miniaturised to limit costs in comparison with traditional testing. These systems are based on two dyes as follows: an invasive fluorescent dyes that serves as a cellular activity marker (a resazurin-like dye reagent) and a noninvasive fluorescent oxygen optosensor dye (an optical sensor). The advantages and limitations of these platforms for biodegradability assessment are presented. Our results confirm the feasibility of these systems for evaluating and screening chemicals for ready biodegradability. The optosensor is a miniaturised version of a component already used in traditional ready biodegradability testing, whereas the resazurin dye offers an interesting new screening mechanism for chemical concentrations greater than 10 mg/l that are not amenable to traditional closed bottle tests. The use of these approaches allows generalisation of high throughput screening methodologies to meet the need of developing new compounds with a favourable ecological profile and also assessment for regulatory purpose.     

Patterns of growth and fluctuating asymmetry: the effects of asymmetrical investment in traits with determinate growth

Fluctuating asymmetry (FA, small and random deviations from perfect symmetry in otherwise bilaterally symmetrical traits) is assumed to depend directly on developmental stability (DS). However, since the processes related to DS operate at a microscopic level, the translation of microscopic errors to the macroscopic character asymmetries (i.e. the DS-FA relation) could be mediated by the cost of growth. To investigate the consequences of this hypothesis, I constructed a model with the following assumptions: the degree of development of a trait depends on the amount of resources allocated to growth, which may differ between individuals and between traits; the cost of growth increases with development, and developmental noise causes random asymmetries in biosynthesis in the two sides of the body. The model predicts that FA follows a parabolic trajectory as growth investment levels increase, regardless of DS. However, depending on the range of variation of investment levels, different relationships (positive, negative or flat) between trait size and asymmetry could be expected. This model may also explain why FA is correlated with the degree of stress in some traits but not in others, and why some traits present a higher level of FA than others. The model also suggests that FA measured on growing traits, at a certain size, could be a more reliable indicator of DS than FA measured on fully grown traits. A study analysing FA patterns of developing and fully grown feathers in the house sparrow (Passer domesticus) corroborates that the levels of FA, and the relationship between asymmetry and feather length, depend on the degree of feather development.     

阿瓜斯阿根廷斯承包区净化处理的新模式： 有助于解决布宜诺斯艾利斯环境问题的工具

布宜诺斯艾利斯市的增长伴随着环境的逐渐恶化,其中包括水流的质量 .随着情况的全面恶化, 1993年政府将饮用水厂进行了为期 30年的私有化,并在布宜诺斯艾利斯市及其 17个郊区社区进行净化处理 .阿瓜斯阿根廷斯 (Aguas Agentinas)的用水操作者是里昂水业集团,为了响应当局的要求,提出并着手进行净化处理的新指导模式,这有助于解决该承包区目前的环境问题 .     

Suitability of Scirpus maritimus for petroleum hydrocarbons remediation in a refinery environment

Purpose  

In the ambit of a project searching for appropriate biological approaches for recovering a refinery soil contaminated with petroleum hydrocarbons (PHC), we compared results obtained in the absence and in the presence of the salt marsh plant Scirpus maritimus or Juncus maritimus or an association of these two plants, which were tested in the refinery environment. Synergistic effects caused by addition of a non-ionic surfactant and/or a bioaugmentation product were also investigated. Major challenges of this study were: field conditions and weathered contamination.     

Heavy metal accumulation by recombinant mammalian metallothionein within Escherichia coli protects against elevated metal exposure

In an effort to minimize the impact on the environment or improve the properties of choice, most engineered nanoparticles used for commercial applications are surface functionalized. The release of these functionalized engineered nanoparticles (FENPs) into the environment can be either deliberate or accidental. Scientific research to date has tended to focus on evaluating the toxicity of FENPs, with less attention being given to exposure assessments or to the study of their general behavior in natural environments. We have therefore investigated the effects of environmental parameters such as pH, NaCl concentration, and natural organic matter concentration on the aggregation kinetics of FENPs with time resolved dynamic light scattering, using functionalized gold nanoparticles (FAuNPs) as a representative of these particles. We also investigated the effects of average particle size, the type of surface capping agent, and particle concentration on FAuNP aggregation kinetics. Our results show that the physico-chemical properties of the capping agent have a greater influence on the aggregation behavior of FAuNPs than either their core composition or their particle size.     

Growth and Histopathological Effects of Chronic Exposition of Marine Pejerrey Odontesthes argentinensis Larvae to Petroleum Water-Soluble Fraction (WSF)

The water-soluble fraction (WSF) of petroleum contains a mixture of polycyclic aromatic hydrocarbons, volatile hydrocarbons, phenols, and heterocyclic compounds, considered deleterious to aquatic biota. Marine “pejerrey” Odontesthes argentinensis (Teleostei: Atherinopsidae) has a great commercial importance in local fisheries and a high potential for aquaculture. The aim of this study was to evaluate the histopathological effects in “pejerrey” larvae exposed to different concentrations of petroleum WSF. The chronic toxicity test was conducted with newly hatched larvae exposed for 21 days to sublethal concentrations of WSF (2.5, 5, 10, and 20 % of WSF), plus one control. Survival and growth were significantly lower in the highest concentration. Several histopathological changes were found in the gills (e.g., hyperplasia, aneurisms, edema, and necrosis), kidney (e.g., nuclear alterations, decrease in the hematopoietic cells), and liver (e.g., hypertrophy, karyorrhexis, and karyopyknosis). An index of branchial lesion was proposed to standardize gill lesions to different pollutants.     

Semifield assessment of the runoff potential and environmental risk of the parasiticide drug ivermectin under Mediterranean conditions

Introduction  

The antiparasitic ivermectin is of particular concern to regulatory agencies. Ivermectin can reach the environment through the direct emission of dung from livestock on pasture and via manure application on agricultural lands.     

Phosphorus effect on Zn adsorption-desorption kinetics in acid soils

The adsorption-desorption kinetics of Zn in the absence and presence of P was studied by using the stirred flow chamber technique. The results thus obtained were compared with those previously obtained for Cu. As with copper, the simultaneous addition of P and Zn in a 1:1 mole ratio to soil was found to significantly increased Zn adsorption relative to the absence of P. Unlike Cu, however, Zn was only adsorbed at fast adsorption sites in the absence of P. In any case, the increased adsorption of Zn in the presence of P was largely due to slow adsorption sites, where Zn²⁺ ion acted as a bridging element between P and organic matter. Following adsorption in both the presence and absence of P, Zn was desorbed to a much higher extent than was Cu. However, the proportion of Zn desorbed after adsorption in the presence of P was significantly lower than in the absence of P. This indicates that Zn binds more strongly to adsorbing surfaces in the presence of P than in its absence.