Saprotrophic soil fungi to improve phosphorus solubilisation and release: In vitro abilities of several species

Modern agriculture is dependent on phosphate rock (PR), which is a nonrenewable resource. Improvement of phosphorus (P) availability for crops in agricultural soils represents a key strategy to slow down the depletion of PR. The aim of this study was to identify potential P biofertilisers among saprotrophic fungal species. We tested 30 fungal strains belonging to 28 taxa (4 Zygomycota and 24 Ascomycota) and with different life strategies. The study showed that many saprotrophic fungi have the ability to mobilise P from insoluble forms according to a variety of mechanisms. Our results expand the pool of P solubilising fungal species, also suggesting a new solubilisation index and shedding light on parameters that could be basic in the selection of efficient soil P-biofertilisers fungi. Rhizopus stolonifer var. stolonifer, Aspergillus niger and Alternaria alternata were found to be the best performing strains in terms of amounts of TCP solubilisation.     

Social–ecological system responses to Hurricane Sandy in the Hudson-Raritan Estuary

The impact of Hurricane Sandy on the Hudson-Raritan estuary (HRE) provided a valuable case study for exploring interactions between long-term environmental degradation, new climatic disturbance stressors, and human behavioral responses. We extend previous research on the ecological effects of major storms to compare water quality and biological parameters three years before and three years after Hurricane Sandy and consider how ecosystem shifts relate to anglers’ perceptions. Results indicate that water clarity and nutrients returned to pre-storm conditions in about one year, while shifts in the biological community, including a significant increase in harmful algal species and declines in zooplankton and Atlantic menhaden, persisted for multiple years, and anglers continued to fish amidst ecosystem decline. Biotic recovery time in the HRE was longer than reports for other shallow estuaries frequently disturbed by hurricanes. Ecological and social responses suggest that the post-storm regime shifts and continued fishing pressure could further environmental degradation.     

Implications of Rural–Urban Migration for Conservation of the Atlantic Forest and Urban Growth in Misiones,Argentina (1970–2030)

Global trends of increasing rural–urban migration and population urbanization could provide opportunities for nature conservation, particularly in regions where deforestation is driven by subsistence agriculture. We analyzed the role of rural population as a driver of deforestation and its contribution to urban population growth from 1970 to the present in the Atlantic Forest of Argentina, a global conservation priority. We created future land-use-cover scenarios based on human demographic parameters and the relationship between rural population and land-cover change between 1970 and 2006. In 2006, native forest covered 50% of the province, but by 2030 all scenarios predicted a decrease that ranged from 18 to 39% forest cover. Between 1970 and 2001, rural migrants represented 20% of urban population growth and are expected to represent less than 10% by 2030. This modeling approach shows how rural–urban migration and land-use planning can favor nature conservation with little impact on urban areas.     

Solubility and adsorption behaviors of chlorpyriphos-methyl in the presence of surfactants

In the present work changes in the adsorption of the pesticide chlorpyrifos-methyl (CLP-m) on soil colloids induced by application of surfactants were determined using a batch equilibrium method. The surfactants used were sodium dodecyl sulphate (SDS), Tween 20, and dihexadecyldimethylammonium bromide (DHAB). The adsorption isotherms of CLP-m in aqueous medium and in surfactant solutions at concentration equal to the critical micelle concentration (CMC) fitted the Freunlich adsorption equation generally with R² values greater than 0.96. While the addition of SDS and DHAB decreased the pesticide adsorption, the addition of Tween 20 increased the pesticide adsorption. The increases or decreases in the adsorption in the experiment revealed that the behavior of CLP-m in soil water-systems mainly depends on the type of surfactant. Moreover water solubility of CLP-m changes by the three surfactants below and above their CMC were studied. While the solubility of CLP-m was enhanced by SDS both below and above the CMC, the solubility of the pesticide was enhanced by DHAB only above the CMC. Tween 20 did not influence the solubility of CLP-m.     

Oxygen,carbon, and nutrient exchanges at the sediment–water interface in the Mar Piccolo of Taranto (Ionian Sea,southern Italy)

In the shallow environment, the nutrient and carbon exchanges at the sediment–water interface contribute significantly to determine the trophic status of the whole water column. The intensity of the allochthonous input in a coastal environment subjected to strong anthropogenic pressures determines an increase in the benthic oxygen demand leading to depressed oxygen levels in the bottom waters. Anoxic conditions resulting from organic enrichment can enhance the exchange of nutrients between sediments and the overlying water. In the present study, carbon and nutrient fluxes at the sediment–water interface were measured at two experimental sites, one highly and one moderately contaminated, as reference point. In situ benthic flux measurements of dissolved species (O₂, DIC, DOC, N-NO₃ ^?, N-NO₂ ^?, N-NH₄ ⁺, P-PO₄ ^3?, Si-Si(OH)₄, H₂S) were conducted using benthic chambers. Furthermore, undisturbed sediment cores were collected for analyses of total and organic C, total N, and biopolymeric carbon (carbohydrates, proteins, and lipids) as well as of dissolved species in porewaters and supernatant in order to calculate the diffusive fluxes. The sediments were characterized by suboxic to anoxic conditions with redox values more negative in the highly contaminated site, which was also characterized by higher biopolymeric carbon content (most of all lipids), lower C/N ratios and generally higher diffusive fluxes, which could result in a higher release of contaminants. A great difference was observed between diffusive and in situ benthic fluxes suggesting the enhancing of fluxes by bioturbation and the occurrence of biogeochemically important processes at the sediment–water interface. The multi-contamination of both inorganic and organic pollutants, in the sediments of the Mar Piccolo of Taranto (declared SIN in 1998), potentially transferable to the water column and to the aquatic trophic chain, is of serious concern for its ecological relevance, also considering the widespread fishing and mussel farming activities in the area.     

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 1: new molecules,metabolism, fate,and transport

Environmental Science and Pollution Research - With the exponential number of published data on neonicotinoids and fipronil during the last decade, an updated review of literature has been...     

From COVID-19 to Green Recovery with natural capital accounting

The COVID-19 pandemic and related social and economic emergencies induced massive public spending and increased global debt. Economic recovery is now an opportunity to rebuild natural capital alongside financial, physical, social and human capital, for long-term societal benefit. Yet, current decision-making is dominated by economic imperatives and information systems that do not consider society’s dependence on natural capital and the ecosystem services it provides. New international standards for natural capital accounting (NCA) are now available to integrate environmental information into government decision-making. By revealing the effects of policies that influence natural capital, NCA supports identification, implementation and monitoring of Green Recovery pathways, including where environment and economy are most positively interlinked.     

Organochlorine contaminants in seven species of Arctic seabirds from northern Baffin Bay

Organochlorine contaminants (OCs) were determined in liver and fat of seven species of seabirds (Alle alle, Uria lomvia, Cepphus grylle, Rissa tridactyla, Pagophila eburnea, Larus hyperboreus, and Fulmaris glacialis) collected in May/June 1998 from the Northwater Polynya in northern Baffin Bay. OC concentrations ranged over an order of magnitude between seabird species and OC groups, with PCBs having the highest concentrations followed by DDT, chlordane, HCH and ClBz. Positive relationships between delta15N (estimator of trophic level) and OC concentrations (lipid basis) were found for all OC groups, showing that trophic position and biomagnification significantly influence OC concentrations in Arctic seabirds. Concentrations of a number of OCs in particular species (e.g., HCH in P. eburnean) were lower than expected based on delta15N and was attributed to biotransformation. P. eburnea and F. glacialis, which scavenge, and R. tridactyla, which migrate from the south, were consistently above the delta15N-OC regression providing evidence that these variables can elevate OC concentrations. Stable isotope measurements in muscle may not be suitable for identifying past scavenging events by seabirds. OC relative proportions were related to trophic position and phylogeny, showing that OC biotransformation varies between seabird groups. Trophic level, migration, scavenging and biotransformation all play important roles in the OCs found in Arctic seabirds.     

Use and fate of pesticides in the Amazon State,Brazil

During the last 30 years, the increase of the human population in the Amazon introduced the need for additional food production and caused the state government to implement programs to increase and improve agricultural production. The production of nontraditional crops introduced several problems unknown to traditional farmers, since they are not well adapted to tropical conditions. Their susceptibility to insects, fungi and other plagues, and the competition with native vegetation forced farmers to use pesticides intensively. Amazonian farmers were not adequately prepared for the use of this new technology; they ignored the risk of pesticides to human health and the environment. Using the region of the state capital Manaus as an example, the characteristics of the pesticide use are described (e.g. the increased use and the lack of personal protective equipment, as well as the legal situation). In detail, the registration status of pesticides used in the State of Amazonas and the state of their registration in the European Union is compared. Finally, it is concluded that the use and the fate of pesticides in the Amazon region has to be monitored. Data of the effects on humans and on the environment have to be collected from the literature or have to be produced in standardized tests, so that an environmental risk assessment becomes possible. Training and information programs are urgently needed in order to build up environmentally sustainable agriculture. Finally, the enforcement of Brazilian laws concerning pesticide registration has to be improved.