Radioactive Isotopes of Strontium,Caesium and Plutonium in Sediments of the Northern Adriatic Sea

Changes in nitrification rates of an acid grassland soil with and without air drying have been monitored over 9 days, after first flushing native nitrate from the soils with deionised water. The results confirmed that full re-establishment of nitrification after air drying takes several days, supporting the hypothesis that any immediate first flush of nitrate from air-dried soils originates from cell lysis or flushing of ‘stored’ nitrate. Ammonium spiking confirmed that nitrification was not ammonium substrate limited. It was also found that ammonium accumulates in the soil during the drying process, providing a substrate pool once the population of nitrifiers has re-established. Over the first week of incubation, nitrate immobilisation was less conspicuous in the soil that had been rewetted after air drying compared with the incubated field moist soil.     

A Comparison of the Short-Term Dynamics of Soil “Damage” Due to Enhanced Nitrogen Deposition As Ammonium Sulphate Or Nitric Acid

An experiment has been conducted to contrast the effects of enhanced oxidised and reduced nitrogen deposition upon key chemical parameters in a Calluna moorland podzol. A 40 cm deep podzol profile, derived from granite, was reconstructed in one hundred 4.2 cm diameter cores. for 20 weeks, the cores were subjected twice weekly to simulated rainfall containing either twice ambient nitrogen deposition in Aberdeen, or further enhanced nitrogen (further 2- and 6-fold increases) as nitric acid or ammonium sulphate. to quantify the dynamics of soil change in each horizon, randomly selected cores were destructively analysed every two weeks and the soils analysed. Increased nitrogen inputs, regardless of form, substantially and immediately reduced surface soil pH_water via the mobile anion or salt effect. for the higher nitrogen treatments, the pH reduction was seen throughout the profile. Longer term soil acidification was also seen in the pH_{calcium chloride} results over the 20 weeks. at a given nitrogen deposition rate, the effects of ammonium sulphate and nitric acid on soil pH_{calcium chloride} were similar. the ammonium sulphate treatments were especially effective at reducing base saturation throughout much of the profile, the direct base cation leaching being associated with substantial ammonium accumulation. the results suggest that the direct base cation leaching caused by ammonium deposition needs to be considered when assessing atmospheric pollution “damage” to heathland soils.     

Long-term trends in invertebrate–habitat relationships under protected and fished conditions

Few studies examine the long-term effects of changing predator size and abundance on the habitat associations of resident organisms despite that this knowledge is critical to understand the ecosystem effects of fishing. Marine reserves offer the opportunity to determine ecosystem-level effects of manipulated predator densities, while parallel monitoring of adjacent fished areas allows separating these effects from regional-scale change. Relationships between two measures of benthic habitat structure (reef architecture and topographic complexity) and key invertebrate species were followed over 17 years at fished and protected subtidal rocky reefs associated with two southern Australian marine reserves. Two commercially harvested species, the southern rock lobster (Jasus edwardsii) and blacklip abalone (Haliotis rubra) were initially weakly associated with habitat structure across all fished and protected sites. The strength of association with habitat for both species increased markedly at protected sites 2 years after marine reserve declaration, and then gradually weakened over subsequent years. The increasing size of rock lobster within reserves apparently reduced their dependency on reef shelters as refuges from predation. Rising predation by fish and rock lobster in the reserves corresponded with weakening invertebrate–habitat relationships for H. rubra and sea urchins (Heliocidaris erythrogramma). These results emphasise that animal–habitat relationships are not necessarily stable through time and highlight the value of marine reserves as reference sites. Our work shows that fishery closures to enhance populations of commercially important and keystone species should be in areas with a range of habitat features to accommodate shifting ecological requirements with ontogenesis.     

Transitions to sustainability in small islands: combining foresight scenarios with multi-criteria analysis to develop viable sustainability strategies in an EOR

Islands face similar challenges for sustainability as continental areas, but their geographic situation conditions their options for development. However, thanks to their clear geographic boundaries, they are an opportunity to think about sustainability in an integrated way. The objective of the study was to explore from a local (island) and regional (archipelago) perspective strategies for sustainability. ‘Participative foresight scenario mapping’ (PFSM) methodology was used to explore the sustainable future of a small island (Flores Island, Azores, Portugal). The need to acknowledge the limit to growth is a key finding of this article. But the research also allowed us to analyse in depth specific strategies that can be applied to different sectors of activity, the most important being to: improve the quality of local products, diversify the economy and increase self-sufficiency. PFSM succeeded in identifying key themes and facilitating debate around these subjects. These findings can inform sustainable development in other islands or territories sharing similar geographic characteristics.     

Sponge-specific bacterial symbionts in the Caribbean sponge, Chondrilla nucula (Demospongiae, Chondrosida)

Marine sponges harbor dense and highly diverse bacterial communities, and some percentage of the microflora appears to be specialized for the sponge habitat. Bacterial diversity was examined in Chondrilla nucula Schmidt to test the hypothesis that some subset of sponge symbiont communities is highly similar regardless of the species of host or habitat requirements of the host. C. nucula was collected from a mangrove channel on Lower Matcumbe Key in the Florida Keys (25°53′N; 80°42′W) in August 1999. Domain-specific universal bacterial primers were used to amplify the 16S rDNA gene from genomic DNA that had been extracted from sponges and the surrounding water. An RFLP technique was used to assess diversity of sponge-associated and environmental bacterial communities. The clone library from C. nucula contained 21 operational taxonomic units (OTUs). None of the 53 OTUs from adjacent water samples were found in the C. nucula library indicating that a distinct community was present in the sponge. Sequence analysis indicated that C. nucula harbors a microbial community as diverse as the microbes from other sponges in different habitats around the world. Phylogenetic analysis placed several C. nucula clones in clades dominated by bacteria that appear to be sponge specialists (e.g., Acidobacteria, Bacteroidetes, and Cyanobacteria). Proportional representation of major bacterial taxonomic groups represented in symbiont communities was compared as a function of geographic location of sponge hosts. This study supports the hypothesis that sponges from different oceans existing in dissimilar habitats harbor closely related bacteria that are distinct from other bacterial lineages and appear specialized for residing within sponges.     

Why geodiversity matters in valuing nature's stage

Geodiversity—the variability of Earth's surface materials, forms, and physical processes—is an integral part of nature and crucial for sustaining ecosystems and their services. It provides the substrates, landform mosaics, and dynamic physical processes for habitat development and maintenance. By determining the heterogeneity of the physical environment in conjunction with climate interactions, geodiversity has a crucial influence on biodiversity across a wide range of scales. From a literature review, we identified the diverse values of geodiversity; examined examples of the dependencies of biodiversity on geodiversity at a site‐specific scale (for geosites <1 km² in area); and evaluated various human‐induced threats to geosites and geodiversity. We found that geosites are important to biodiversity because they often support rare or unique biota adapted to distinctive environmental conditions or create a diversity of microenvironments that enhance species richness. Conservation of geodiversity in the face of a range of threats is critical both for effective management of nature's stage and for its own particular values. This requires approaches to nature conservation that integrate climate, biodiversity, and geodiversity at all spatial scales.     

Application of UV-activated persulfate and peroxymonosulfate processes for the degradation of 1,2,3-trichlorobenzene in different water matrices

Environmental Science and Pollution Research - The presence of a large number of micropollutants in the environment, including priority and emerging substances, poses a significant risk to surface...