A carbon budget of a small humic lake: an example of the importance of lakes for organic matter cycling in boreal catchments

Lakes play an important role in the cycling of organic matter in the boreal landscape, due to the frequently high extent of bacterial respiration and the efficient burial of organic carbon in sediments. Based on a mass balance approach, we calculated a carbon budget for a small humic Swedish lake in the vicinity of a potential final repository for radioactive waste in Sweden, in order to assess its potential impact on the environmental fate of radionuclides associated with organic matter. We found that the lake is a net heterotrophic ecosystem, subsidized by organic carbon inputs from the catchment and from emergent macrophyte production. The largest sink of organic carbon is respiration by aquatic bacteria and subsequent emission of carbon.dioxide to the atmosphere. Although the annual burial of organic carbon in the sediment is a comparatively small sink, it results in the build-up of the largest carbon pool in the lake. Hence, lakes may simultaneously disperse and accumulate organic-associated radionuclides leaking from a final repository.     

Does the Harvard/U.S. Environmental Protection Agency Ambient Particle Concentrator change the toxic potential of particles?

Inhalation exposure to urban air particles is known to increase morbidity in humans and animals. Our group utilizes the Harvard/U.S. Environmental Protection Agency Ambient Particle Concentrator (HAPC) to generate concentrated aerosols of outdoor air particles for experimental exposures. We have reported increased pathologic responses to inhalation of concentrated urban air particles and identified silicon (as silicate) as an element associated with many of these responses. Using silicate-rich Mt. St. Helen's volcanic ash (MSHA), we exposed three groups of Sprague-Dawley rats by inhalation for 6 hr to filtered air, MSHA, or MSHA passed though the HAPC. Twenty-four hours following exposure, bronchoalveolar lavage was performed to assess total cell count, differential cell count, protein, lactate dehydrogenase, and n-beta-glucosaminidase levels. Peripheral blood was examined for packed cell volume, total protein, total white cells, and differential cell count. Morphologic studies localized particles in the lung and assessed pulmonary vasculature. No significant differences were observed among any of the groups in any parameter measured including morphometric analysis of pulmonary vasoconstriction. Scanning electron microscopy and X-ray analysis identified particles as silicates typical of MSHA throughout the lung. These findings suggest that particles passing through the HAPC have no change in their toxic potential in an exposure setting where particle deposition in the lung has occurred.     

Frequency of PPAR-γ, FTO and ABCC8 genetic variation in Pakistani cardiovascular smokers

Environmental Science and Pollution Research - Smoking is considered as one of the major reasons behind genetic variations in cardiometabolic disorders. However, effect of nicotine via smoking on...     

Antioxidant activity and enzyme inhibitory potential of Euphorbia resinifera and E. officinarum honeys from Morocco and plant aqueous extracts

Natural products may be applied in a wide range of domains, from agriculture to food and pharmaceutical industries. In this study, the antioxidant properties and the capacity to inhibit some enzymatic activities of Euphorbia resinifera and Euphorbia officinarum aqueous extracts and honeys were assessed. The physicochemical characteristics were also evaluated. Higher amounts of iron, copper and aluminium were detected in E. officinarum honey, which may indicate environmental pollution around the beehives or inadequate storage of honey samples. This honey sample showed higher amounts of total phenols and better capacity for scavenging superoxide anion free radicals and DPPH free radicals as compared with E. resinifera honey, but poorer capacity for inhibiting lipoxygenase, acetylcholinesterase, tyrosinase and xanthine oxidase. The ratio plant mass:solvent volume (1:100) and extraction time (1 - 2 h) were associated with higher total phenols and better antioxidant activities and lipoxygenase, acetylcholinesterase and tyrosinase inhibitory activities, regardless of the plant species. The aqueous extracts had systematically higher in vitro activities than the respective honey samples.

     

Assessment of semi-natural habitats and landscape features on Irish farmland: New insights to inform EU Common Agricultural Policy implementation

Concerns over the loss of biodiversity and ecosystem services in farmland have prompted the development of agri-environment policy measures aimed at reducing farming pressure and maintaining semi-natural habitats in farmed landscapes. However, further knowledge is needed to guarantee successful agri-environment measures implementation. The current study assessed the quantity and the quality of semi-natural habitats in farms across a gradient of farming intensities in two contrasting regions in Ireland. Policy protection seemed fundamental for semi-natural habitats preservation. Habitats not protected by agricultural policy relied on extensive farming and are in danger of disappearing if they are intensified or abandoned. Due to the lack of policy incentives for habitat quality, no correlations were found between farming intensity and share of semi-natural habitats with habitat quality. Therefore, extensive farming and retention of habitats alone may not reverse the decline of farmland quality and biodiverisity and, thus, measures incentivising the environmental quality may be more successful.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01344-6) contains supplementary material, which is available to authorized users.     

Magnetic properties of biogenic selenium nanomaterials

Environmental Science and Pollution Research - Bioreduction of selenium oxyanions to elemental selenium is ubiquitous; elucidating the properties of this biogenic elemental selenium (BioSe) is thus...     

Developing an analytical framework for assessing progress toward ecosystem-based management

Ecosystem-based management (EBM) has become a key instrument of contemporary environmental policy and practice. Given the increasingly important role of EBM, there is an urgent need for improved analytical approaches to assess if and to what extent EBM has been accomplished in any given case. Drawing on the vast literature on EBM, we identify five key ecosystem aspects for assessment. By linking these aspects to four phases of management, we develop an interdisciplinary, analytical framework that enables a high-resolution and systematic assessment of the degree of specificity and integration of ecosystem aspects in an EBM. We then apply the framework to evaluate five coastal EBM initiatives in Sweden, four on the Baltic coast and one on the west coast. Our results demonstrate our framework’s usefulness for in-depth and continuous assessments of processes aiming for EBM, and also provide an empirical basis for inferences about the key challenges for successful EBM.     

Carbon partitioning among the first trophic levels in the North Western Adriatic Basin

In the frame of PRISMA II Project samples for plankton analyses were carried out during four cruises (June, 1996; February and June, 1997; February, 1998) in order to assess the relative importance in term of biomasses of the three main size fractions (pico- <2 r µm, nano- 2-20 r µm and micro-plankton >20 r µm). Spatial and temporal distribution of the three plankton fractions were described as abundance and contribution to the total carbon content in an area between Po River mouth and Rimini. The relative contribution of picoplankton resulted higher in the offshore zone, while that of nanoplankton in the inshore waters. In February 1998 microphytoplankton, mainly constituted by diatoms, was very abundant in the inshore waters. Micro-zooplankton was always very scarce. Cluster analyses performed on these data grouped the stations on the basis of their community structure, and agreed with the hydrological features. Small size classes contributed more significantly to the total plankton carbon content in most of the situations. Microplankton fraction contribution was relevant only during spring diatom bloom of February 1998 and with a less extent in the confined coastal summer blooms.