Phytoavailability and Fractions of Iron and Manganese in Calcareous Soil Amended with Composted Urban Wastes

Little is known about the effects of applying composted urban wastes on the phytoavailability and distribution of iron (Fe) and manganese (Mn) among chemical fractions in soil. In order to study this concern several experiments in pots containing calcareous soil were carried out. The received treatments by adding separately two rates (20 and 80 Mg ha^?1) of municipal solid waste (MSW) compost and/or municipal solid waste and sewage sludge (MSW-SS) co-compost. The cropping sequence was a lettuce crop followed by a barley crop. It was observed that treatments amended with composted urban wastes tended to promote slight increases in lettuce yield compared to the control. The highest Fe levels in lettuce were found when higher rates of MSW-SS co-compost were applied; these values were significant compared to those obtained in the other treatments. In all cases, the application of organic materials increased the concentration and uptake of Mn in lettuce compared to the control; however, these increases were significant only when higher rates of MSW compost were applied. The organic amendments had beneficial delayed effects on barley yields, showing, in most cases, significant increases compared to the control. In this context, treatments with MSW compost were found to be more effective than the equivalent treatments amended with MSW-SS co-compost. Compared to the control, composted urban wastes increased Fe concentration in straw and rachis, and decreased Fe concentration in barley grain. Similarly, a decreased concentration of Mn in the dry matter of barley crop grown in soils treated with composted urban wastes was observed.     

Consensus on Criteria for Potential Areas for Wolf Reintroduction in Mexico

Abstract: Given the conflict with human interests that in many cases results in the extirpation of large carnivores, acceptance of their reintroduction is a considerable challenge. By the 1980s Mexican wolves (Canis lupus) were extinct in the wild. In 1998 a population was reintroduced in the Blue Range Mountains of New Mexico (U.S.A.). Efforts to reintroduce the species in Mexico have been ongoing since the late 1980s. Four teams working independently identified 6 areas in northern Mexico in the historic range of Mexican wolves, where reintroductions could potentially be successful. Each team used different methods and criteria to identify the areas, which makes it difficult to prioritize among these areas. Therefore, members of the different teams worked together to devise criteria for use in identifying priority areas. They identified areas with high, intermediate, and low potential levels of conflict between wolves and humans. Areas with low potential conflict had larger buffers (i.e., distance from human settlement to areas suitable for wolves) around human settlements than high‐ and intermediate‐conflict areas and thus were thought most appropriate for the first reintroduction. High‐conflict areas contained habitat associated with wolf presence, but were closer to human activity. The first reintroduction of Mexican wolves to Mexico occurred in October 2011 in one of the identified low‐conflict areas. The identification of suitable areas for reintroduction represents a crucial step in the process toward the restoration of large carnivores. Choice of the first reintroduction area can determine whether the reintroduction is successful or fails. A failure may preclude future reintroduction efforts in a region or country.     

Net impact of remediation

Following years of progress in designing and executing cleanups of contaminants at waste sites, the U.S. Air Force, state regulatory groups, and others are crafting methods to evaluate broader considerations of risk in remedial decisions. Integrating worker and climate risks into remediation efforts may confer significant benefits, but challenges exist to identifying, assessing, and accounting for them in the remedial process. For sites where future risk posed by contamination far exceeds the risk posed to workers who may be exposed to the contaminants during the remedial process, limiting the range of decision inputs to those presented by the site conditions made sense and provided a net benefit to human health and the environment. There are other sites, however, where future risk posed by the in situ contamination are at levels comparable to the real risks posed to workers, ecology, and even emerging concerns about climate change. For these sites, a net risk reduction cannot be assumed to be a result of remedial action, challenging the remedial community to develop new approaches to ensure positive results. © 2009 Wiley Periodicals, Inc.     

Demographic Effects of Harvesting Epiphytic Bromeliads and an Alternative Approach to Collection

Abstract: Hundreds of epiphytic bromeliads species are harvested from the wild for trade and for cultural uses, but little is known about the effects of this harvest. We assessed the potential demographic effects of harvesting from the wild on 2 epiphytic bromeliads: Tillandsia macdougallii, an atmospheric bromeliad (adsorbs water and nutrients directly from the atmosphere), and T. violaceae, a tank bromeliad (accumulates water and organic material between its leaves). We also examined an alternative to harvesting bromeliads from trees—the collection of fallen bromeliads from the forest floor. We censused populations of T. macdougallii each year from 2005 to 2010 and of T. violaceae from 2005 to 2008, in Oaxaca, Mexico. We also measured monthly fall rates of bromeliads over 1 year and monitored the survival of fallen bromeliads on the forest floor. The tank bromeliad had significantly higher rates of survival, reproduction, and stochastic population growth rates (λ_s) than the atmospheric bromeliad, but λ_s for both species were <1, which suggests that the populations will decline even without harvest. Elasticity patterns differed between species, but in both, survival of large individuals had high elasticity values. No fallen bromeliads survived more than 1.5 years on the forest floor and the rate of bromeliad fall was comparable to current harvest rates. Low rates of population growth recorded for the species we studied and other epiphytic bromeliads and high elasticity values for the vital rates that were most affected by harvest suggest that commercial harvesting in the wild of these species is not sustainable. We propose the collection of fallen bromeliads as an ecologically and, potentially, economically viable alternative.     

National and regional determinants of tropical deforestation in Colombia

Global tropical deforestation continues to occur at high rates despite political attention. National-level forest baselines are being established all over the world to guide the implementation of several policy mechanisms. However, identifying the direct and indirect drivers of deforestation and understanding the complexity of their interlinkages are often difficult. We first analyzed deforestation between 1990 and 2005 at the national level and found an annual deforestation rate of 0.62 %. Next, we performed separate analyses for four natural regions in Colombia and found annual deforestation rates between 0.42 and 1.92 %. Using general linear models, we identified several direct causes and underlying factors influencing deforestation at the national level: rural population density, cattle, protected areas, and slope. Significant differences in deforestation rates and causes were found across regions. In the Caribbean region, drivers of loss are urban population, unsatisfied basic needs, slope, and precipitation and four land use variables (illicit crops, pastures, cattle, and fires). In the Orinoco region, crops are the main driver of forest loss, and in the Amazonian region, deforestation is primarily due to fires related to the colonization front. Policy mechanisms will have to take into account regional patterns to successfully balance development and forest preservation in Colombia.     

Understanding the processes in a historically relevant thermal and mineral spring water by using mixing and inverse geochemical models

Environmental Geochemistry and Health - The thermal mineral water of Peñón de los Baños spa (Mexico City) has been used for over 500&nbsp;years starting in pre-Hispanic times and...     

Batch and continuous adsorption of Cu(II) and Zn(II) ions from aqueous solution on bi-functionalized sugarcane-based biosorbent

Environmental Science and Pollution Research - A new one-pot synthesis method optimized by a 23 experimental design was developed to prepare a biosorbent, sugarcane bagasse cellulose succinate...     

Large-scale modeling of reactive solute transport in fracture zones of granitic bedrocks

Final disposal of high-level radioactive waste in deep repositories located in fractured granite formations is being considered by several countries. The assessment of the safety of such repositories requires using numerical models of groundwater flow, solute transport and chemical processes. These models are being developed from data and knowledge gained from in situ experiments such as the Redox Zone Experiment carried out at the underground laboratory of Äspö in Sweden. This experiment aimed at evaluating the effects of the construction of the access tunnel on the hydrogeological and hydrochemical conditions of a fracture zone intersected by the tunnel. Most chemical species showed dilution trends except for bicarbonate and sulphate which unexpectedly increased with time. Molinero and Samper [Molinero, J. and Samper, J. Groundwater flow and solute transport in fracture zones: an improved model for a large-scale field experiment at Äspö (Sweden). J. Hydraul. Res., 42, Extra Issue, 157–172] presented a two-dimensional water flow and solute transport finite element model which reproduced measured drawdowns and dilution curves of conservative species. Here we extend their model by using a reactive transport which accounts for aqueous complexation, acid–base, redox processes, dissolution–precipitation of calcite, quartz, hematite and pyrite, and cation exchange between Na⁺ and Ca²⁺. The model provides field-scale estimates of cation exchange capacity of the fracture zone and redox potential of groundwater recharge. It serves also to identify the mineral phases controlling the solubility of iron. In addition, the model is useful to test the relevance of several geochemical processes. Model results rule out calcite dissolution as the process causing the increase in bicarbonate concentration and reject the following possible sources of sulphate: (1) pyrite dissolution, (2) leaching of alkaline sulphate-rich waters from a nearby rock landfill and (3) dissolution of iron monosulphides contained in Baltic seafloor sediments. Based on these results, microbially mediated processes are postulated as the most likely hypothesis to explain the measured increase of dissolved bicarbonates and sulphates after tunnel construction.     

Can we meet targets for biofuels and renewable energy in transport given the constraints imposed by policy in agriculture and energy?

The deployment of biofuels is significantly affected by policy in energy and agriculture. In the energy arena, concerns regarding the sustainability of biofuel systems and their impact on food prices led to a set of sustainability criteria in EU Directive 2009/28/EC on Renewable Energy. In addition, the 10% biofuels target by 2020 was replaced with a 10% renewable energy in transport target. This allows the share of renewable electricity used by electric vehicles to contribute to the mix in achieving the 2020 target. Furthermore, only biofuel systems that effect a 60% reduction in greenhouse gas emissions by 2020 compared with the fuel they replace are allowed to contribute to meeting the target. In the agricultural arena, cross-compliance (which is part of EU Common Agricultural Policy) dictates the allowable ratio of grassland to total agricultural land, and has a significant impact on which biofuels may be supported. This paper outlines the impact of these policy areas and their implications for the production and use of biofuels in terms of the 2020 target for 10% renewable transport energy, focusing on Ireland. The policies effectively impose constraints on many conventional energy crop biofuels and reinforce the merits of using biomethane, a gaseous biofuel. The analysis shows that Ireland can potentially satisfy 15% of renewable energy in transport by 2020 (allowing for double credit for biofuels from residues and ligno-cellulosic materials, as per Directive 2009/28/EC) through the use of indigenous biofuels: grass biomethane, waste and residue derived biofuels, electric vehicles and rapeseed biodiesel.