A pest is a pest is a pest? The dilemma of neotropical leaf-cutting ants: Keystone taxa of natural ecosystems

Leaf-cutting ants of the generaAcromyrmex andAtta are considered the principal polyphagous pests of the Neotropics Although some members of these genera are of economic importance, have a broad geographic distribution, and are extremely good colonizers, others are endemic and closely interact with native ecosystems. Control is generally practiced against any colony, irrespective of its taxonomic status. Indiscriminate control coupled with habitat destruction threatens endemic species with extinction, and, through habitat simplification, favors other pest species. As nests ofAtta are large, having several square meters of nest surface, the endemic taxa can be easily used as environmental indicators for natural ecosystems Likewise, the pest species can be used to detect environmental disturbance As these ants are keystone species and easily identified by nonspecialists, efforts should be made to integrate these into viable conservation programs     

Current status and perspectives of accelerated carbonation processes on municipal waste combustion residues

The increasing volumes of municipal solid waste produced worldwide are encouraging the development of processes to reduce the environmental impact of this waste stream. Combustion technology can facilitate volume reduction of up to 90%, with the inorganic contaminants being captured in furnace bottom ash, and fly ash/APC residues. The disposal or reuse of these residues is however governed by the potential release of constituent contaminants into the environment. Accelerated carbonation has been shown to have a potential for improving the chemical stability and leaching behaviour of both bottom ash and fly ash/APC residues. However, the efficacy of carbonation depends on whether the method of gas application is direct or indirect. Also important are the mineralogy, chemistry and physical properties of the fresh ash, the carbonation reaction conditions such as temperature, contact time, CO₂ partial pressure and relative humidity. This paper reviews the main issues pertaining to the application of accelerated carbonation to municipal waste combustion residues to elucidate the potential benefits on the stabilization of such residues and for reducing CO₂ emissions. In particular, the modification of ash properties that occur upon carbonation and the CO₂ sequestration potential possible under different conditions are discussed. Although accelerated carbonation is a developing technology, it could be introduced in new incinerator facilities as a “finishing step” for both ash treatment and reduction of CO₂ emissions.     

Beach vulnerability assessment of a protected area of the Northern Campania coast (Southern Italy)

A detailed and multidisciplinary study of physical and biotic factors of a coastal sector of southern Italy, the Pineta della foce del Garigliano SCI (Site of Community Importance) area, has been carried out in the frame of the European research project LIFE + Nature & Biodiversity PROVIDUNE. We evaluated the degree of dunes vulnerability (Dune Vulnerability Index, DVI) and sustainable anthropogenic load (carrying capacity) of the emerged beach of the study area, which is largely affected by shoreline retreat and degradation of dune habitat. The values of about 0.6 of the DVI in the two key sectors of the study area suggest a high level of vulnerability of beach/dune system due to both natural and human factors. The partial vulnerability index related to the geomorphological condition exhibits the highest values, as a consequence of a coastal system largely affected by recent and present-day beach erosion and severe hydrodynamics processes. Several inadequate human practises have been recognized in the study area whose impact appears to be an important factor in controlling the reduction of the beach-dune system resilience. Integrated analysis of DVI and carrying capacity suggests that the northern and central sectors of the study area have a high level of dune vulnerability due to hydrodynamic and geomorphological factors whereas the human impact can be considered relatively less important. The southern sector of the study area is featured by a well-developed infrastructure system, which is able to assure a sustainable beach occupation. Nevertheless, significant interventions such as dune replacement by permanent or ephemeral infrastructures, uncontrolled pedestrian or vehicular access and inappropriate use of mechanical beach cleaning have been recognized in this sector of the beach. These long-lasting impacts have promoted the dismantling of large sector of the dune habitats. Obtained results allowed identifying the critical area where appropriate actions can be performed for the mitigation of impacts, the conservation of dune habitats and their sustainable use.