A column method for determination of leaching of polycyclic aromatic hydrocarbons from aged contaminated soil

In this study a column leaching method for investigation of hydrophobic organic contaminants (HOCs) leaching from soil was developed. The method set-up is based on a recycled flow of sterile water through a soil column with a sedimentation chamber mounted on top of the column, in connection with on-line filtration. The combination of a sedimentation chamber and an on-line filtration enables the measurement of leaching concentrations from contaminated materials consisting of very fine particle fractions. In addition, by using on-line solid phase extraction, minute amounts of leaching HOCs may be captured and quantified with high accuracy and reproducibility. The method was applied successfully on a contaminated aged soil sample and the leaching behavior of seven PAHs, with three to six aromatic rings, was monitored for more than 1600 h under saturated conditions. The tested PAHs were fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)pyrene and benzo(ghi)perylene. The method proved to be reliable and capable of providing data on leachable amounts of the PAHs under field-like conditions and over a longer period of time. The results indicated low availability of the studied contaminants since only a minor fraction (0.3%) of the initial amount of PAHs in the soil was removed during the experiment (liquid/solid-ratio of 700 l/kg). Thus PAHs in aged contaminated soil are not to be expected to be released to any great extent only by leaching with water.     

瑞典来自农业的食品品质特性对消费者支付意愿的影响

本文采用让受访问者做选择题的办法,研究来自农业的食品品质特性与消费者支付意愿的关系,目前这些食品在瑞典还没有销售.数据是通过大规模的邮件调查获得的,同时用一个随机参数的Logit模型来估计.我们的结果表明:同一产品和相同特性,消费者的支付意愿均存在差异.不同产品间为品质特性排序时也是这样.而且,我们还发现可能以转基因作物作为饲料的动物食品市场上表现不力.最后,我们的结论支持被称作"cheap-talk"的研究方法能有效地减小选择试验地的外在误差.在食品行业中,我们的结论对产品差别化战略的构建和对食品政策的形成等方面十分有用.     

Socioeconomic characteristics of suitable wolf habitat in Sweden

Large carnivores are ecologically important, but their behaviour frequently put them in conflict with humans. I suggest that a spatial co-occurrence of suitable habitat and relatively poor socioeconomic conditions in rural areas may contribute to inflated human–carnivore conflict. Here, I test if there is potential for such an explanation for the human–wolf conflict in Sweden, a conflict that is arguably not congruent with the costs and damages imposed by the wolf population. I found negative correlations between wolf habitat suitability within Swedish municipalities and indicators of their relative socioeconomic conditions. I argue that geographic socioeconomic inequality may contribute to the Swedish human-wolf conflict, partly by the use of wolves as symbols for socioeconomic dissent and partly by using them as scapegoats for socioeconomic conditions. Therefore, regional policies aimed at alleviating geographic socioeconomic inequities may create a more favourable environment for solving the human-wolf conflict in Sweden.Supplementary InformationThe online version of this article (10.1007/s13280-021-01524-y) contains supplementary material, which is available to authorized users.     

A comparison of three models of 137Cs transfer in forest ecosystems.

The predictions of three models of 137Cs transfer in forest ecosystems (FOA, LOGNAT and FORESTLAND) were compared. The scenario for the model-model comparison consisted of an acute dry deposition of 137Cs over a coniferous forest. The model predictions were subsequently compared (model-data comparison) with values derived from experimental data measured in forests of the Bryansk region in Russia that were contaminated by the Chernobyl accident and that have similar characteristics to the forests described in the scenario. The predictions of radiocaesium levels in the litter-soil layer, berries, needles, wood, whole tree and moose made with the models were in relatively good agreement with each other (within a factor of 1.4-2.9). The best agreement was observed for berries and moose and the worst for wood. There was also good agreement between the model predictions for the same variables and the experimental data (within a factor of 1.2 3.2). In this case, the best agreement was observed for the litter-soil layer and the worst for wood and the whole tree. Overall, at least for the studied scenario and for the first 10 years after deposition, any of the models can be used if the final aim is to estimate average concentrations in different forest components. The agreement between the model predictions worsens with time and there were differences in the form of the time dependencies predicted by the models, especially for wood. This may lead to larger differences between the model predictions and the experimental data for times beyond the period for which data were available for comparison (10 years after the deposition).     

Predation risk and the territory value of cover: an experimental study

In an experiment on territorial brown trout (Salmo trutta), we addressed the novel hypothesis that protective cover increases the value of a territory in relation to the perceived level of predation risk. We predicted that territory holders should invest more resources defending territories with cover than territories without cover, and that defence should increase as predation risk increases. First, trout were allowed to establish ownership in territories with or without overhead cover. Second, predation risk was manipulated by simulating aerial predator attacks in half of the territories of each type, whereupon the preference for cover was estimated. Third, owners of the four types of territories were staged in dyadic contests against size-matched intruders. Territory owners showed a preference for cover, which increased further after simulated predator attacks. In subsequent contests, conflicts over territories with cover were settled faster than conflicts over territories without cover, which may suggest that the value of cover increases the motivational asymmetry between owner and intruder. Consistent with our hypothesis, owners of territories with cover were much more aggressive if they had been subjected to predator attacks the day before the conflict. These results suggest that territory owners are able to estimate the value of protective cover in response to variation in the level of predation risk in the habitat.Communicated by J. Krause     

Perspectives on Local Environmental Security, Exemplified by a Rural South African Village

This paper analyzes the human–nature interaction in a village in rural South Africa. It discusses preconditions, perceptions, and consequences of natural resource use, and places these findings into a regional and historical context. Applying an interdisciplinary perspective, the study uses interviews, questionnaires, remote sensing, and participatory mapping to analyze land cover changes and local perceptions of the environment. The study area is located in a former homeland (Transkei), a setting where well-recorded conflicts in the human–nature sphere have previously been triggered by population pressure, apartheid policies, and other historical, political, and social reasons. A small-scale and subjective conceptualization of environmental security is used as an approach to analyze local livelihood strategies in a selected village. The results indicate that the environment is not the highest priority in local survival strategies. Instead, formal and informal jobs and governmental grants are the most important security strategies. There are thus no major conflicts resulting from the interaction between the local population and the natural resources in this specific area. Explanations to this pattern can partly be found in historical contexts, which include apartheid policies, re-localizations, and a system of migrant labor. The study also suggests that general truths about a region such as Transkei might be misleading in specific localities. For relevant and successful environmental management and development planning however, it is crucial that decision-makers be able to get a clear picture of local situations and adjust their plans accordingly.     

Does the energy labelling system for domestic tumble dryers serve its purpose?

Tumble dryers sold on the market today are labelled according to their energy efficiency. This labelling system has primarily two purposes: to guide buyers to a product with low energy use, lower cost and lower environmental impact and to encourage producers to develop even more energy-efficient products. Tumble dryers are optimized for their maximum capacity, which is used as the standard load for determining the energy label. Three different tumble dryers have been tested with different drying loads. Results indicate that all the tested tumble dryers have significantly lower energy efficiency when drying small loads. In order to encourage the development of tumble dryers with high energy efficiency at drying loads used in ordinary households, the standards for the energy labelling system should be revised.     

Cost–benefit analysis of beach-cast harvest: Closing land-marine nutrient loops in the Baltic Sea region

Harvesting beach-cast can help mitigate marine eutrophication by closing land-marine nutrient loops and provide a blue biomass raw material for the bioeconomy. Cost–benefit analysis was applied to harvest activities during 2009–2018 on the island of Gotland in the Baltic Sea, highlighting benefits such as nutrient removal from the marine system and improved recreational opportunities as well as costs of using inputs necessary for harvest. The results indicate that the activities entailed a net gain to society, lending substance to continued funding for harvests on Gotland and assessments of upscaling of harvest activities to other areas in Sweden and elsewhere. The lessons learnt from the considerable harvest experience on Gotland should be utilized for developing concrete guidelines for carrying out sustainable harvest practice, paying due attention to local conditions but also to what can be generalized to a wider national and international context.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01641-8.     

Bioaccumulation and lack of oxidative stress response in the ragworm H. diversicolor following exposure to Ra in sediment

The main effluent from oil and gas production, produced water, from some platforms in the North Sea contains elevated concentrations of ²²⁶Ra. The aim of this study was to investigate whether ²²⁶Ra in sediment would accumulate in and affect sediment-dwelling organisms. In addition, we wanted to determine if the bioavailability would be modulated by the presence of a scale inhibitor which is used during oil and gas production. Hediste diversicolor was therefore exposed to different levels of ²²⁶Ra (30–6600 Bq kg⁻¹) in combination with scale inhibitor in the sediments in a flow through system. The levels of radioactivity in the exposures were close to levels that can be measured in proximity to oil/gas production facilities. ²²⁶Ra spiked to natural sediment partitioned into pore water and accumulated in the sediment-dwelling polychaete following a four-week exposure period. The results suggest that ²²⁶Ra did not bind strongly to sediment (low sediment:water partitioning coefficient), but it was not shown to bioaccumulate in any great extent (bioaccumulation factors of 0.019–0.022). Exposure of H. diversicolor in sediments with up to 6600 Bq kg⁻¹²²⁶Ra had no measurable effect on the total oxyradical scavenging capacity of the organisms compared to control. So although they accumulated the alpha-emitter, the treatments did not appear to cause oxidative stress in polychaete tissues.