Effect of amendment C:N ratio on plant richness, cover and metal content for acidic Pb and Zn mine tailings in Leadville, Colorado

Biosolids and woody debris were applied with target C:N ratios of 8:1 to 50:1 to phytotoxic, acidic, high metal mine tailings to test the effect of amendment C:N ratio on native plant restoration. Total soil C decreased over time indicating an active microbial community. The 8:1 treatment initially had no growth, the highest plant cover for the final sampling (86.8+/-13.8%) and the lowest number of species (3.33+/-0.4). The greatest number of species was in the 30:1 treatment (5.44+/-0.45). Plant cover increased over time for all treatments from 44.7% in 2001 to 71% in 2005. This response was consistent across all except for the 30:1 treatment, which showed a slight decrease in the final year (65+/-11%). Volunteer species and evidence of animal grazing were observed in all amended plots. Results indicate that a C:N ratio>/=20:1 increased species diversity.     

The Significance of the North Water Polynya to Arctic Top Predators

The North Water polynya (~76°N to 79°N and 70°W to 80°W) is known to be an important habitat for several species of marine mammals and sea birds. For millennia, it has provided the basis for subsistence hunting and human presence in the northernmost part of Baffin Bay. The abundance of air-breathing top predators also represents a potential source of nutrient cycling that maintains primary production. In this study, aerial surveys conducted in 2009 and 2010 were used for the first time to map the distribution and estimate the abundance of top predators during spring in the North Water. Belugas (Delphinapterus leucas) were not detected north of 77°20′N but were found along the coast of West Greenland and offshore in the middle of the North Water with an abundance estimated at 2245 (95 % CI 1811–2783). Narwhals (Monodon monoceros) were widely distributed on the eastern side of the North Water with an estimate of abundance of 7726 (3761–15 870). Walruses (Odobenus rosmarus) were found across the North Water over both shallow and deep (>500 m) water with an estimated abundance of 1499 (1077–2087). Bearded (Erignathus barbatus) and ringed seals (Phoca hispida) used the large floes of ice in the southeastern part of the North Water for hauling out. Most polar bears (Ursus maritimus) were detected in the southern part of the polynya. The abundances of bearded and ringed seals were 6016 (3322–10 893) and 9529 (5460–16 632), respectively, and that of polar bears was 60 (12–292). Three sea bird species were distributed along the Greenland coast (eiders, Somateria spp.), in leads and cracks close to the Greenland coast (little auks, Alle alle) or widely in open water (thick-billed guillemots, Uria lomvia).     

Development,local livelihoods,and vulnerabilities to global environmental change in the South American Dry Andes

Climate change will increasingly impact large areas of South America, affecting important natural resources and people’s livelihoods. These impacts will make rural people disproportionately more vulnerable, given their dependency on ecosystem services and their exposure to other stressors, such as new rules imposed by agribusiness and trends toward the commodification of natural resources. This paper focuses on the vulnerability of rural communities in Andean drylands of Argentina, Bolivia, and Chile, showing how different economic and political pathways lead to different levels of vulnerability. The paper begins with a brief discussion of the methodological and theoretical concept of vulnerability, which framed the research. Starting from the premise that global environmental change impacts are strongly linked to styles of development, the discussion explores the diverse institutional capital and governance schemes as well as different development styles in the case studies and their role in increasing or reducing local vulnerability to climate and water scarcity. Using a comparative perspective, the exposures and adaptive capacities of rural actors in three river basins are discussed, emphasizing situations that speak for the ways in which development styles counteract or magnify conditions of vulnerability. The analysis considers irrigated and non-irrigated agriculture, water property interests, different productive structures (viticulture, horticulture, etc.), producer typologies (large/small, export, etc.), and geographical location. Finally, the paper offers some insights about development style and adaptive capacities of rural people to overcome those vulnerabilities.     

Visibility and Mass Concentration in a Nonurban Environment

Considerable interest is currently directed toward atmospheric visibility and its relationship to particle size and mass concentration. Previous work has been limited to heavily polluted urban areas, and visibility studies have not included particle size characterization. An air sampling program was carried out in a nonurban, low pollution area to relate: (a) total particulate mass concentration measured with a high-volume sampler, (b) particulate mass size distribution measured with aerodynamic size selective samplers, and (c) visual range measured by the integrating nephelometer. For low suspended particulate mass concentrations, the following relationship was defined between visual range (L_v) and mass concentration (M ? μg/m³):     

Deciding on equity or parity: a test of situational,cultural, and individual factors

Previous cross-cultural research in distributive justice has neglected the situational and individual determinants of allocation preferences. This study incorporated the cultural value of Individualism–Collectivism (I–C), situational demands of task interdependence and system goals, and individual achievement motivation to examine their effects on the allocation decisions made by U.S. Americans and Hong Kong Chinese. It was found that the Americans and the Chinese in the study responded to situational demands in a similar fashion, i.e. equity was preferred under circumstances of low interdependence and the productivity goal whereas parity was preferred under circumstances of high interdependence and the solidarity goal. It was also found that in the U.S., I–C had no significant relation with the allocation differential (between the bonus amounts for the highest and the lowest performer), and the achievement motivation interacts with levels of interdependence and with goal priorities; in Hong Kong, both I–C and the achievement motivation related negatively to the allocation differential. Research and managerial implications for international management were discussed. © 1998 John Wiley & Sons, Ltd.     

Investigating habitat value to inform contaminant remediation options: approach

Habitat valuation methods are most often developed and used to prioritize candidate lands for conservation. In this study the intent of habitat valuation was to inform the decision-making process for remediation of chemical contaminants on specific lands or surface water bodies. Methods were developed to summarize dimensions of habitat value for six representative aquatic and terrestrial contaminated sites at the East Tennessee Technology Park (ETTP) on the US Department of Energy Oak Ridge Reservation in Oak Ridge, TN, USA. Several general valuation metrics were developed for three broad categories: site use by groups of organisms, site rarity, and use value added from spatial context. Examples of use value metrics are taxa richness, a direct measure of number of species that inhabit an area, complexity of habitat structure, an indirect measure of potential number of species that may use the area, and land use designation, a measure of the length of time that the area will be available for use. Measures of rarity included presence of rare species or communities. Examples of metrics for habitat use value added from spatial context included similarity or complementarity of neighboring habitat patches and presence of habitat corridors. More specific metrics were developed for groups of organisms in contaminated streams, ponds, and terrestrial ecosystems. For each of these metrics, cutoff values for high, medium, and low habitat value were suggested, based on available information on distributions of organisms and landscape features, as well as habitat use information. A companion paper describes the implementation of these habitat valuation metrics and scoring criteria in the remedial investigation for ETTP.     

Re-evaluation of the conformational structure of sulfadiazine species using NMR and ab initio DFT studies and its implication on sorption and degradation

In the environment, the sorption and the degradation of organic pollutants are of increasing interest. The investigation of the chemical structures provides a basis for the development of a suitable binding model approach and for the mechanistic understanding of the chemical fate processes. The aim of this study was the identification of different species of the antibiotic compound sulfadiazine (SDZ) using (1)H and (13)C NMR experiments and ab initio density functional theory (DFT) calculations. In the neutral, aprotic solvent dimethylsulfoxide-d(6) (DMSO-d(6)), a new sulfadiazine structure containing an O-H-N hydrogen bond was identified. In the protic solvent water-d(2) and in dependence on pH and the position of the amidogen hydrogen atom nine possible SDZ conformations were analyzed and five structures were identified. Good conformity between theory and calculation of (1)H NMR was observed. Unfortunately, (13)C NMR is not sensitive enough for comparison and differentiation. In order to verify the identified structures, additional NBO/NLMO (natural localized molecular orbital) analyses were conducted (calculation of net atomic charges, bond polarity, atomic valence, and electron delocalization). Finally, conformation optimizations were performed in order to investigate the stability of the SDZ species. We showed that SDZ contains no S=O double bond, but that it has two S-O single bonds. Surprisingly, negative charges were observed at the pyrimidine nitrogen atom. With these results, the known structure of SDZ was revised. Studies of the geometrical structure and the torsion angles showed that SDZ is very flexible and can be easily fitted to the sorbent. These observations would explain the strong sorbance and hence the rapid formation of non-extractable residues in the environment because SDZ acts as a strong ligand. These results show that that the sulfonamide hydrogen is important for the biological activity but the pyrimidine nitrogen and the sulfonamide oxygen is responsible for the sorbance in environment.     

Organizational practices and workplace health and safety: A cross-sectional study in manufacturing companies

We report the results of a mail questionnaire for 312 manufacturing firms in the province of Ontario (Canada). We conducted a cross-sectional analysis of workplace level health and safety policies, practices and attitudes. Analyses were conducted across firm categories based upon lost-time frequency rate (LTFR) data. Lower LTFRs were associated with paternalistic initiatives, recording of occupational health and safety (OHS) measures, greater involvement of workers in decision-making, and better managerial attitudes concerning the importance of OHS. The composition of the Joint Health and Safety Committee (JHSC), a committee mandated in all workplaces we sampled, differed according to injury rate: the mean number of worker (vs. management) members on the JHSC was higher for lower injury sites, and the mean number of worker members attending JHSC meetings was also higher for lower injury worksites. In addition, workplaces with lower LTFR benefitted by having JHSCs with more executive functions and greater worker involvement. In conclusion, managerial and worker participation in OHS initiatives characterizes safer workplaces. Also, general concern of management towards OHS—illustrated by both attitudes and concrete actions—is also associated with lower injury rates.     

Policies towards proposals for large-scale natural resource projects: Attenuation versus postponement

The authors examine the problem of dealing with the environmental impact of uranium mining in Australia and consider its wider implications. Government, faced with unknown environmental and social damage from the initiation of uranium mining in northern Australia, has initiated an environmental impact assessment procedure. This requires the appellant company to provide information about the proposed project and its alternatives and is often followed by a period of ‘postponement’. This is compared with an alternative procedure, ‘attenuation’, allowing the project to proceed on a reduced scale in order to obtain information. Comparisons are made between the information which might be obtained by the two alternative procedures and the expected relative benefits and costs from a postponed project and an attenuated project.