Spatial variation in soil carbon in the organic layer of managed boreal forest soil—implications for sampling design

We studied within-site spatial variation of the carbon stock in the organic layer of boreal forest soil. A total of 1,006 soil samples were taken in ten forest stands (five Scots pine stands and five Norway spruce stands). Our results indicate that the spatial autocorrelation disappears at a distance of 75-225 cm. This spatial autocorrelation should be taken into account in the sampling design by locating the sampling points at adequate intervals. With a sample size of over 20-30 samples per site, additional soil samples do not notably improve the precision of the site mean estimate. An adequate sample size is dependent on the purpose of sampling and on the site-specific soil variation. Our results on the dependence between sample size and precision of the mean estimates can be applied in designing efficient soil monitoring in boreal coniferous forests.     

Release of uranium from rock matrix--a record of glacial meltwater intrusions?

Uranium release observed in a rock matrix around water-carrying fractures was studied using U-series disequilibrium (USD) modelling and mass balance calculations. Several release scenarios were tested, with specific attention to the glacial aspects. The release appears to have occurred in two or three violent episodes during the last 300 ky. A release after the last glaciation can be excluded on mass flow grounds. Continuous release for more than 300 ky can be excluded on radioactive disequilibrium grounds. Repeated inflows of oxic glacial meltwater seem to have triggered the release episodes.     

Endocrine and metabolic alterations in the mink (Mustela vison) due to chronic phytoestrogen exposure

Phytoestrogens are natural components of plant-based food items with beneficial health effects. The aim of the present study was to investigate the chronic effects of dietary phytoestrogens, genistein (8 mg kg(-1) day(-1)) and beta-sitosterol (50 mg kg(-1) day(-1)), on the weight regulation of the mink (Mustela vison). The parental generation was exposed from August 2002 to May-June 2003 to either beta-sitosterol or genistein, while the kits were exposed through gestation and lactation. Food consumption and body masses were monitored monthly. Plasma lipid, glucose, total protein and hormone (ghrelin, leptin, triiodothyronine and thyroxine) concentrations were measured from the parents in August 2002, January 2003 and at the end of the experiment in May-June 2003 when the kits were 21 days of age. Relative food intake was higher in the beta-sitosterol-exposed minks than in the control or genistein minks in September 2002. Plasma leptin and total protein concentrations were lower in the beta-sitosterol kits compared to the control kits. Furthermore, plasma ghrelin levels and liver phosphorylase activities of the mink kits were higher due to genistein exposure. In mink kits, exposure to both phytoestrogens reduced the plasma thyroxine concentrations. The kidney glycogen concentrations and the muscle phosphorylase activities of phytoestrogen-treated adult minks were elevated. The results of this study suggest that minks are sensitive to perinatal phytoestrogen exposure.     

Postmetamorphic Xenopus laevis shows decreased plasma triiodothyronine concentrations and phosphorylase activity due to subacute phytosterol exposure

Postmetamorphic South African clawed frogs (Xenopus laevis) were exposed to a phytosterol mixture (ca. 80% β-sitosterol and less sitostanol, campesterol, and campestanol) for 14 days at 30 μg l⁻¹ in a flow-through system. The effects of phytosterols (PS) on the plasma thyroid hormone (T₃ and T₄), testosterone, leptin-immunoreactive peptide and tissue glycogen concentrations were determined. The following enzyme activities were also analyzed from the liver and muscle: glycogen phosphorylase and lipase, and from the liver only: glucose-6-phosphatase. The plasma T₃ concentration was lower in the PS-exposed female frogs. Both muscle lipase and glycogen phosphorylase activities were also lower in the PS-exposed animals. These results could indicate that the basal metabolic rate and locomotion activity of the frogs were decreased. The effects could not be attributed to the possible estrogenicity of the PS mixture. Further studies will be needed to evaluate the possible significance of these effects.     

Release of uranium from rock matrix—a record of glacial meltwater intrusions?

Uranium release observed in a rock matrix around water-carrying fractures was studied using U-series disequilibrium (USD) modelling and mass balance calculations. Several release scenarios were tested, with specific attention to the glacial aspects. The release appears to have occurred in two or three violent episodes during the last 300 ky. A release after the last glaciation can be excluded on mass flow grounds. Continuous release for more than 300 ky can be excluded on radioactive disequilibrium grounds. Repeated inflows of oxic glacial meltwater seem to have triggered the release episodes.     

Physiological evaluation of chemical protective suit systems (CPSS) in hot conditions.

This job-related experiment investigated physiological strain in subjects wearing impermeable chemical protective suit systems (CPSSs) weighing about 28 kg. Two types of CPSSs were studied: the self-contained breathing apparatus was carried either inside or outside the suit. Eight healthy and physically fit male firefighter instructors aged 32 to 45 years volunteered for the study. The test drill, performed at a dry, windless ta of 40 degrees C, was divided into 2 consecutive work sessions of 14.5 min (a 20-min rest between) including typical operational work tasks. Considerable thermal and maximal cardiovascular strain and intense subjective discomfort measured in the firefighters emphasize the need to limit working time in hot conditions to only 10-12 min while wearing CPSSs. The present results indicate that the exceptionally heavy physical load and psychological stress during operations in chemical emergencies must be considered in the assessment of the cardiovascular capacity of ageing firefighters using CPSSs.     

Governance experiments in climate action: empirical findings from the 28 European Union countries

Climate targets call for novel policy measures to facilitate widespread adoption of low-carbon solutions and innovations. The literature on socio-technical systems argues that experimentation has a prominent role in enabling sustainability transition. Experiments represent ways of testing new ideas and methods across a wide range of policy fields. Governance experiments in particular can support accelerated diffusion of new solutions, because they integrate policy with innovations. Here, types of success factors in the implementation of governance experiments to mitigate climate change are examined. Statistical analysis of sustainability innovations in the 28 European Union countries indicates that the types of success factors in governance experiments differ from those of product and social experiments. Governance experimentation is more positioned within socio-technical regimes than in strategic niches. These results suggest that governance experiments may indeed provide new transition opportunities towards low-carbon societies.     

Formation of volatile iodinated alkanes in soil: results from laboratory studies

Volatile iodinated organic compounds play an important role in the tropospheric photochemical system, but the current knowledge of the known sources and sinks of these alkyl iodides is still incomplete. This paper describes a new source of alkyl iodides from the pedosphere. Different organic-rich soils and humic acid were investigated for their release of volatile organoiodides. Six volatile organoiodides, iodomethane, iodoethane, 1-iodopropane, 2-iodopropane, 1-iodobutane and 2-iodobutane were identified and their release rates were determined. We assume an abiotic reaction mechanism induced by the oxidation of organic matter by iron(III). The influence of iron(III), iodide and pH on the formation of alkyl iodides was investigated. Additionally, different organic substances regarded as monomeric constituents of humus were examined for the production of alkyl iodides. Two possible reaction pathways for the chemical formation of alkyl iodides are discussed. As humic acids and iron(III) are widespread in the terrestrial environment, and the concentration of iodide in soil is strongly enriched (compared to seawater), this soil source of naturally occurring organoiodides is suggested to contribute significantly to the input of iodine into the troposphere.