Biofiltration of fugitive methane emissions from landfills using scum from municipal wastewater treatment plants as alternative substrate

Journal of Material Cycles and Waste Management - Biofilters have been recognized as a key technology in the mitigation of greenhouse gases (GHG) emitted by landfills. This study aimed to evaluate...     

Climate adaptation of biodiversity conservation in managed forest landscapes

Conservation of biodiversity in managed forest landscapes needs to be complemented with new approaches given the threat from rapid climate change. Most frameworks for adaptation of biodiversity conservation to climate change include two major strategies. The first is the resistance strategy, which focuses on actions to increase the capacity of species and communities to resist change. The second is the transformation strategy and includes actions that ease the transformation of communities to a set of species that are well adapted to the novel environmental conditions. We suggest a number of concrete actions policy makers and managers can take. Under the resistance strategy, five tools are introduced, including: identifying and protecting forest climate refugia with cold-favored species; reducing the effects of drought by protecting the hydrological network; and actively removing competitors when they threaten cold-favored species. Under the transformation strategy, we suggest three tools, including: enhancing conditions for forest species favored by the new climate, but currently disfavored by forest management, by planting them at suitable sites outside their main range; and increasing connectivity across the landscape to enhance the expansion of warm-favored species to sites that have become suitable. Finally, we suggest applying a landscape perspective and simultaneously managing for both retreating and expanding species. The two different strategies (resistance and transformation) should be seen as complementary ways to maintain a rich biodiversity in future forest ecosystems.     

Database-driven models of the world's Large Marine Ecosystems

We present a new methodology for database-driven ecosystem model generation and apply the methodology to the world's 66 currently defined Large Marine Ecosystems. The method relies on a large number of spatial and temporal databases, including FishBase, SeaLifeBase, as well as several other databases developed notably as part of the Sea Around Us project. The models are formulated using the freely available Ecopath with Ecosim (EwE) modeling approach and software. We tune the models by fitting to available time series data, but recognize that the models represent only a first-generation of database-driven ecosystem models. We use the models to obtain a first estimate of fish biomass in the world's LMEs. The biggest hurdles at present to further model development and validation are insufficient time series trend information, and data on spatial fishing effort.     

Efficacy of stable isotope ratios in assigning endangered migrants to breeding and wintering sites.

A primary constraint on effective conservation of migratory animals is our inability to track individuals through their annual cycle. One such animal is the endangered southwestern subspecies of the Willow Flycatcher, which is difficult to distinguish from conspecifics. Identifying wintering regions used by the endangered subspecies would be an important step in formulating an effective conservation strategy. Our objective was to use stable isotope ratios as a means of identifying wintering sites of Southwestern Willow Flycatchers. We analyzed stable isotope ratios of carbon, nitrogen, and hydrogen from feathers of breeding and wintering Willow Flycatchers. Based on winter samples, we document a positive trend in hydrogen isotope ratios across latitude. We also found that Willow Flycatchers use C4 food webs south of 8 degrees N latitude, but we found no evidence of use of C4 food webs farther north. Nitrogen stable isotope ratios of feathers showed no discernable geographic variation. Discriminant function analyses, based on stable isotope ratios of wintering Willow Flycatchers, were only useful (>50% accurate) for assigning individuals to winter regions if the regions were large and the threshold probability for assignment was relatively high. When using these discriminant functions, most breeding samples of Southwestern Willow Flycatchers were assigned to two wintering regions: central Mexico and Ecuador. We think that assignment of Southwestern Willow Flycatchers to Ecuador is unrealistic. Given the large percentages of samples that could not be classified with certainty, we are not confident that these two regions are truly more likely to harbor wintering Southwestern Willow Flycatchers than other winter regions. We think our inconclusive results are due primarily to weak and nonlinear gradients in isotope ratios across the winter range of Willow Flycatchers.     

UV-B protecting compounds in the marine algaPhaeocystis pouchetii from Antarctica

Phaeocystis pouchetii (Hariot) Lagerheim is widely distributed in polar waters, and forms massive near-surface blooms in the marginal ice-edge zone around Antarctica during spring and summer. UV irradiance in the Antarctic marine environment is reportedly as high in October and November as in mid-summer due to stratospheric ozone depletion. Because of the location and timing of theP. pouchetii bloom, this prymnesiophyte will be exposed to high levels of UV-B (280 to 320 nm) radiation. Colourless water-soluble compounds, produced by the colonial stage in the life cycle of this alga, absorb strongly between 250 and 370 nm, with absorbance maxima at 271 and 323 nm. The concentration of these compounds in culturedP. pouchetii depends on the strain, stage in the life cycle, and presence of bacteria. As well as conferring substantial protection to this alga, these substances may also provide UV protection to other organisms present in the water column.     

Tidal variations in dissolved and particulate phase radionuclide activities in the Esk estuary,England, and their distribution coefficients and particulate activity fractions

Measurements have been made of the radionuclide activities, particularly for plutonium isotopes, of the particulate and dissolved fractions of the tidal waters of the Esk Estuary. A wide range of K_d values indicates the lack of equilibrium conditions in this dynamically changing environment. The particulate activity contributes a major part of the activity of the suspension, with reworked estuarine sediment providing an important component of this. The estuarine circulation system results in the dispersion of particulate radionuclides into the low salinity upper reaches of the estuary, where plutonium isotopes are apparently mobilised, enriching the dissolved fraction activity.     

Entitlements, coping mechanisms and indicators of access to food: wollo region, ethiopia, 1987-88

Vulnerability to famine and traditional responses to food insecurity in Wollo Region, Ethiopia are described. The timeliness of anthropometric and socio-economic indicators of access to food is then assessed, using data collected in Wollo by Save the Children Fund during 1987–88, a period of drought and subsequent food insecurity. The movements of different indicators are then examined for evidence of correspondence at sub-district level. The author concludes that although anthropometric status does not respond as early as crop yield or grain price, a deterioration in anthropometric status is detectable at a stage when livestock and migration indicators show little or no change and mortality rate remains unaffected. At sub-district level, changes in different indicators are not well-correlated.     

Trends in atmospheric ammonium concentrations in relation to atmospheric sulfate and local agriculture

Ammonium (NH(4)(+)) concentrations in air and precipitation at the Institute of Ecosystem Studies (IES) in southeastern New York, USA declined over an 11-year period from 1988 to 1999, but increased from 1999 to 2001. These trends in particulate NH(4)(+) correlated well with trends in particulate SO(4)(2-) over the 1988-2001 period. The NH(4)(+) trends were not as well correlated with local cattle and milk production, which declined continuously throughout the period. This suggests that regional transport of SO(4)(2-) may have a greater impact on concentrations of NH(4)(+) and subsequent deposition than local agricultural emissions of NH(3). Ammonium concentrations in precipitation correlated significantly with precipitation SO(4)(2-) concentrations for the 1984-2001 period although NH(4)(+) in precipitation increased after 1999 and SO(4)(2-) in precipitation continued to decline after 1999. The correlation between NH(4)(+) and SO(4)(2-) was stronger for particulates than for precipitation. Particulate NH(4)(+) concentrations were also correlated with particulate SO(4)(2-) concentrations at 31 of 35 eastern U.S. CASTNet sites that had at least 10 years of data. Air concentrations of NH(4)(+) and SO(4)(2-) were more strongly correlated at the sites that were located within an agricultural landscape than in forested sites. At most of the sites there was either no trend or a decrease in NH(4)(+) dry deposition during the 1988-2001 period. The sites that showed an increasing trend in NH(4)(+) dry deposition were generally located in the southeastern U.S. The results of this study suggest that, in the northeastern U.S., air concentrations of NH(4)(+) and subsequent deposition may be more closely linked to SO(4)(2-) and thus SO(2) emissions than with NH(3) emissions. These results also suggest that reductions in S emissions have reduced NH(4)(+) transport to and NH(4)(+)-N deposition in the Northeast.     

Sequestration of priority pollutant PAHs from sediment pore water employing semipermeable membrane devices

Semipermeable membrane devices (SPMDs) were employed to sample sediment pore water in static exposure studies under controlled laboratory conditions using (control pond and formulated) sediments fortified with 15 priority pollutant polycyclic aromatic hydrocarbons (PPPAHs). The sediment fortification level of 750 ng/g was selected on the basis of what might be detected in a sediment sample from a contaminated area. The sampling interval consisted of 0, 4, 7, 14, and 28 days for each study. The analytical methodologies, as well as the extraction and sample cleanup procedures used in the isolation, characterization, and quantitation of 15 PPPAHs at different fortification levels in SPMDs, water, and sediment were reported previously (Williamson, M.S. Thesis, University of Missouri-Columbia, USA; Williamson et al., Chemosphere (This issue--PII: S0045-6535(02)00394-6)) and used for this project. Average (mean) extraction recoveries for each PPPAH congener in each matrix are reported and discussed. No procedural blank extracts (controls) were found to contain any PPPAH residues above the method quantitation limit, therefore, no matrix interferences were detected. The focus of this publication is to demonstrate the ability to sequester environmental contaminants, specifically PPPAHs, from sediment pore water using SPMDs and two different types of fortified sediment.     

Kinetics of oxidation of methylhydrazines in water. Factors controlling the formation of 1,1-dimethylnitrosamine

The kinetics of oxidation of methylhydrazine ($\text{MMH}$) and 1,1-dimethylhydrazine ($\text{UDMH}$) by dissolved oxygen in water has been measured at various acidities as a function of catalyst (cupric ion) concentration. In dilute solutions the oxidation occurs through a cupric ion catalyzed process as well as by an uncatalyzed step. The extent of formation of nitrosodimethylamine ($\text{NDMA}$) depends upon the initial $\text{UDMH}$ concentration. In dilute solutions $\text{NDMA}$ is not formed, but in more concentrated solutions, $\text{NDMA}$ formation increases with increasing $\text{UDMH}$ content, reaches a maximum at 60–80% $\text{UDMH}$ (by volume) and then decreases. The $\text{NDMA}$ yield appears to approximately parallel the viscosity of the medium, and it is speculated that the factors which control viscosity may also be responsible for governing $\text{NDMA}$ formation.