Test of aerobic TCE degradation by willows (Salix viminalis) and willows inoculated with TCE-cometabolizing strains of Burkholderia cepacia

Environmental Science and Pollution Research - Trichloroethylene (TCE) is a widespread soil and groundwater pollutant and clean-up is often problematic and expensive. Phytoremediation may be a...     

Spatially explicit sensitivity and uncertainty analysis for multicriteria-based vulnerability assessment

This research analyses the application of spatially explicit sensitivity and uncertainty analysis for GIS (Geographic Information System) multicriteria decision analysis (MCDA) within a multi-dimensional vulnerability assessment regarding flooding in the Salzach river catchment in Austria. The research methodology is based on a spatially explicit sensitivity and uncertainty analysis of GIS-CDA for an assessment of the social, economic, and environmental dimensions of vulnerability. The main objective of this research is to demonstrate how a unified approach of uncertainty and sensitivity analysis can be applied to minimise the associated uncertainty within each dimension of the vulnerability assessment. The methodology proposed for achieving this objective is composed of four main steps. The first step is computing criteria weights using the analytic hierarchy process (AHP). In the second step, Monte Carlo simulation is applied to calculate the uncertainties associated with AHP weights. In the third step, the global sensitivity analysis (GSA) is employed in the form of a model-independent method of output variance decomposition, in which the variability of the different vulnerability assessments is apportioned to every criterion weight, generating one first-order (S) and one total effect (ST) sensitivity index map per criterion weight. Finally, in the fourth step, an ordered weighted averaging method is applied to model the final vulnerability maps. The results of this research demonstrate the robustness of spatially explicit GSA for minimising the uncertainty associated with GIS-MCDA models. Based on these results, we conclude that applying the variance-based GSA enables assessment of the importance of each input factor for the results of the GIS-MCDA method, both spatially and statistically, thus allowing us to introduce and recommend GIS-based GSA as a useful methodology for minimising the uncertainty of GIS-MCDA.     

The astysphere and urban geochemistry—a new approach to integrate urban systems into the geoscientific concept of spheres and a challenging concept of modern geochemistry supporting the sustainable development of planet earth

Background, aim, and scope  In 1875, the geoscientist Walter Suess introduced several spheres, such as the lithosphere and the atmosphere to promote a comprehensive understanding of the system earth. Since then, this idea became the dominating concept for the understanding of the distribution of chemical elements in the system earth. Meanwhile, due to the importance of human beings on global element fluxes, the term anthroposphere was introduced. Nevertheless, in face of the ongoing urbanization of the earth, this concept is not any more adequate enough to develop a comprehensive understanding of global element fluxes in and between solid, liquid, and gaseous phases. This article discusses a new concept integrating urbanization into the geoscientific concept of spheres. Main features  No geological exogenic force has altered the earth’s surface during the last centuries in such an extent as human activity. Humans have altered the morphology and element balances of the earth by establishing agrosystems first and urban systems later. Currently, urban systems happen to become the main regulators for fluxes of many elements on a global scale due to ongoing industrial and economic development and a growing number of inhabitants. Additionally, urban systems are constantly expanding and cover more and more former natural and agricultural areas. For nature, urban systems are new phenomena, which never existed in previous geological eras. The process of the globe’s urbanization concurrently is active with the global climate change. In fact, urban systems are a major emitter for climate active gases. Thus, beside the global changes in economy and society, urbanization is an important factor within the global change of nature as is already accepted for climate, ecosystems, and biodiversity. Results  Due to the fact that urbanization has become a global process shaping the earth and that the urban systems are globally cross-linked among each other, a new geoscientific sphere has to be introduced: the astysphere. This sphere comprises the parts of the earth influenced by urban systems. Accepting urbanization as global ongoing process forming the astysphere comprehensively copes with the growing importance of urbanization on the creation of present geologic formations. Discussion  Anthropogenic activities occur mainly in rural and urban environments. For long lasting periods of human history, human activities mainly were focused on hunting and agriculture, but since industrialization, urbanized areas became increasingly important for the material and energy fluxes of earth. Thus, it seems appropriate to classify the anthroposphere into an agriculturally and an urban-dominated sphere, which are the agrosphere (Krishna 2003) and the astysphere (introduced by Norra 2007). Conclusions  We have to realize that urban systems are deposits, consumers, and transformers of resources interacting among each other and forming a network around the globe. Since the future of human mankind depends on the sustainable use of available resources, only a global and holistic view of the cross-linked urban systems forming together the astysphere provide the necessary geoscientific background understanding for global urban material and energy fluxes. If we want to ensure worth-living conditions for future generations of mankind, we have to develop global models of the future needs for resources by the global metasystem of urban systems, called astysphere. Perspectives  The final vision for geoscientific research on the astysphere must be to design models describing the global process of urbanization of the earth and the development of the astysphere with respect to fluxes of materials, elements, and energy as well as with respect to the forming of the earth’s face. Besides that, just from the viewpoint of fundamental research, the geoscientific concept of spheres has to be complemented by the astysphere if this concept shall fully represent the system earth.

Ozone exposure of field-grown winter wheat affects soil mesofauna in the rhizosphere

A 2-year open-top chamber experiment with field-grown winter wheat (Triticum aestivum L. cv. Astron) was conducted to examine the effects of ozone on plant growth and selected groups of soil mesofauna in the rhizosphere. From May through June in each year, plants were exposed to two levels of O₃: non-filtered (NF) ambient air or NF+ 40 ppb O₃ (NF+). During O₃ exposure, soil sampling was performed at two dates according to different plant growth stages. O₃ exposure reduced above- and below-ground plant biomass in the first year, but had little effect in the second year. The individual density of enchytraeids, collembolans and soil mites decreased significantly in the rhizosphere of plants exposed to NF+ in both years. Differences were highest around anthesis, i.e. when plants are physiologically most active. The results suggest that elevated O₃ concentrations may influence the dynamic of decomposition processes and the turnover of nutrients.     

Genotoxic biomonitoring of agricultural workers exposed to pesticides in the north of Sinaloa State, Mexico

Genotoxic damage was evaluated in 70 agricultural workers, 25 women and 45 men, exposed to pesticides in Las Grullas, Ahome, Sinaloa, Mexico, with an average of 7 years of exposure. The effect was detected through the sister chromatid exchanges (SCE) in lymphocytes of peripheral blood and micronuclei (MN) and other nuclear anomalies (NA) in buccal exfoliated cells. Also, the influence on cellular proliferation kinetics (CPK) was studied by means of the replication index (RI) and the cytotoxic effect was examined with the mitotic index (MI). The non-exposed group consisted of 70 other persons, 21 women and 47 men from the city of Los Mochis, Sinaloa, Mexico. Significant differences between the exposed and the non-exposed groups were observed in SCE, CPK, MI, MN and NA. Analysis of variance revealed that age, gender, smoking and alcohol consumption did not have a significant effect on genetic damage. However, there was a correlation between exposure time to pesticides and SCE frequency. These results could have been due to the exposure of workers to pesticides containing different chemical compounds. This study afforded valuable data to estimate the possible risk to health associated with pesticide exposure.     

Temporal pessimism and spatial optimism in environmental assessments: An 18-nation study

The personal assessments of the current and expected future state of the environment by 3232 community respondents in 18 nations were investigated at the local, national, and global spatial levels. These assessments were compared to a ranking of each country's environmental quality by an expert panel. Temporal pessimism (“things will get worse”) was found in the assessments at all three spatial levels. Spatial optimism bias (“things are better here than there”) was found in the assessments of current environmental conditions in 15 of 18 countries, but not in the assessments of the future. All countries except one exhibited temporal pessimism, but significant differences between them were common. Evaluations of current environmental conditions also differed by country. Citizens' assessments of current conditions, and the degree of comparative optimism, were strongly correlated with the expert panel's assessments of national environmental quality. Aside from the value of understanding global trends in environmental assessments, the results have important implications for environmental policy and risk management strategies.     

Song-type sharing in song sparrows: implications for repertoire function and song learning

One hypothesis for the function of song repertoires is that males learn multiple song types so that they may share songs with neighbors, allowing them to match during territorial interactions. In at least one song sparrow population, in Washington, territorial males share a high proportion of song types with their neighbors and use these shared songs in matching. We recorded song sparrows in Pennsylvania and quantified sharing of whole songs and song segments. We found that song sharing is an order of magnitude less common in the Pennsylvania population. We found sharing of song segments to be significantly more common than the sharing of whole songs in three of the five fields we examined, while we found no significant differences between whole and partial song sharing in the remaining two fields. Finally, we found no evidence that sharing is greater between birds in the same field compared to birds in different fields. Taken with the data from Washington song sparrows, these results provide evidence for intraspecific geographic variation in the organization of song repertoires, and suggest that song sharing has not been a strong selective force in the evolution of song repertoires in song sparrows as a species. Furthermore, Washington and Pennsylvania song sparrows differ in how they learn song, in that Washington birds copy whole songs, while Pennsylvania birds appear to copy and recombine song segments, as has been found in laboratory studies of song learning. Thus both song learning and the function of song repertoires differ between populations of song sparrows. Such intraspecific geographic variation offers a unique opportunity to explore the ecological and historical factors which have influenced the evolution of song. Received: 30 June 1997 / Accepted after revision: 8 March 1998     

Cyclo-stationary maximum cross-covariance analysis for exogenously forced environmental systems

The response of an ecological system to external forcings shows marked seasonality and complex time delays. In order to take seasonality into account, the assumption of stationarity inherent in most statistical models for time series is replaced here by more flexible cyclo-stationarity. To describe the dominant modes of the cross-covariance structure of the system and the forcing, temporal (orthonormal) patterns are derived. They are estimated by a singular value decomposition of the cyclo-stationary sample cross-covariance matrix. These patterns allow to formulate a prediction scheme for the system once the forcing is known. The method has comparatively little tendency for multi-collinearity, so that it is well applicable also for multivariate settings and shorter data records. The method is illustrated for an aquatic ecosystem with distinct phases of a biological succession.     

地下水铀污染的原位微生物还原与固定:在美国能源部田纳西橡树岭放射物污染现场的试验

总结了美国斯坦福大学和橡树岭国家实验室等在美国能源部田纳西州橡树岭综合试验基地进行的铀污染原位微生物修复阶段性试验结果.本试验利用微生物以乙醇为电子供体还原地下水和沉积物中的六价铀为不溶解的四价铀,使之原位固定化.随后通过加入溶解氧和硝酸盐来试验微生物还原后的地下水层中还原固定态铀的稳定性.通过预处理和长期间隔注入乙醇...     

甲基叔丁基醚(MTBE)蒸腾流浓度因子(TSCF)的试验评估

甲基叔丁基醚(MTBE)是北美燃料市场最常用的汽油添加剂，由于在土壤中的不吸附性和极高的水溶性．MT-BE已成为一种蔓延性的地下水污染物．植物修复技术被认为是目前对MTBE污染治理最为有效的方法之一．蒸腾流浓度因子（TSCF)作为植物修复技术中十分重要的参数，其通常是用污染物的辛醇-水分配系数(Kow)直接评估的。由于不同植物其体内脂肪含量不同，所以如果仅用污染物的Kow值来计算其TSCF值，往往不能准确表达污染物在植物体内的传输行为．由于MTBE在植物体内不发生降解，植物挥发是MTBE植物修复技术中唯一的作用机理．本实验用一自行设计的植物反应器来测定MTBE在不同温度条件下的TSCF值．长出新根须和嫩叶的柳树(Salix alba)枝条在一容积500mL的植物反应器中生长9-12d(其中MTBE溶液500mL，浓度4．81-6．60mg／L)来观察柳树对MTBE的吸收。MTBE的去除率和柳树的蒸腾量之间的关系用来计算其TSCF值．在15℃，20℃和25℃条件下，MTBE的TSCF值分别为0.58,0.75和0.49．本实验结果表明，柳树对MTBE的吸收是一个被动的行为，并且MTBE在柳树体内随蒸腾流的传输也有一定的限度。图2表1参11。