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.     

Comparison of data from two vegetation monitoring methods in semi-natural grasslands

Two vegetation-monitoring methods were compared: subplot frequency analysis (SF) and visual estimation of percentage cover (VE). Two independent observers collected data from two semi-natural, species-rich grasslands on three different occasions during the growth-season. During the last data collection period, survey times were also recorded. The two different data sets from the two methods were compared using partial Redundancy Analyses. The purpose of the comparison was to identify the method that explains most of the relevant variation in biodiversity-monitoring (inter-and intra-site variation), and the variation irrelevant when evaluating data (systematic inter-observer variation and variation due to phenological changes). Compared with VE data, more variation in SF data could be explained by spatial variables, while less variation depended on the observer and time of year surveyed. SF also found more species per plot but took on average five times longer to complete than VE. In conclusion, the different methods are suitable for different purposes: SF is more suitable for purposes demanding high accuracy and high precision, such as long-term biodiversity-monitoring when the identification of small changes has high priority, while VE might be more suitable for a one-time mapping of a large area.     

Internal ecosystem feedbacks enhance nitrogen-fixing cyanobacteria blooms and complicate management in the Baltic Sea

Eutrophication of the Baltic Sea has potentially increased the frequency and magnitude of cyanobacteria blooms. Eutrophication leads to increased sedimentation of organic material, increasing the extent of anoxic bottoms and subsequently increasing the internal phosphorus loading. In addition, the hypoxic water volume displays a negative relationship with the total dissolved inorganic nitrogen pool, suggesting greater overall nitrogen removal with increased hypoxia. Enhanced internal loading of phosphorus and the removal of dissolved inorganic nitrogen leads to lower nitrogen to phosphorus ratios, which are one of the main factors promoting nitrogenfixing cyanobacteria blooms. Because cyanobacteria blooms in the open waters of the Baltic Sea seem to be strongly regulated by internal processes, the effects of external nutrient reductions are scale-dependent. During longer time scales, reductions in external phosphorus load may reduce cyanobacteria blooms; however, on shorter time scales the internal phosphorus loading can counteract external phosphorus reductions. The coupled processes inducing internal loading, nitrogen removal, and the prevalence of nitrogen-fixing cyanobacteria can qualitatively be described as a potentially self-sustaining "vicious circle." To effectively reduce cyanobacteria blooms and overall signs of eutrophication, reductions in both nitrogen and phosphorus external loads appear essential.     

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.     

可持续力的制度框架:俄罗斯和波罗的海国家林业部门的比较分析

苏维埃体系解体之后,原苏维埃共和国之间森林管理的分歧变得明显.在波罗的海国家的林业部门已经发生根本变化的时候,俄罗斯却没能形成一个能适应社会-生态恢复力先决条件的制度框架.本文认为,可持续发展需要一种能够具有适应和学习能力,因而能够以实验的方式对政策不断地进行评估和再调整的制度框架.但是,这需要有参与机制,我们相信波罗的海国家在这方面正在走出一条更有希望的路子.最后,得出结论,只有建立了可持续的制度框架,社会-生态恢复力才能成为前共产主义国家自然资源管理的重要特征.     

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.     

Scenario Development as a Basis for Formulating a Research Program on Future Agriculture: A Methodological Approach

To increase the awareness of society to the challenges of global food security, we developed five contrasting global and European scenarios for 2050 and used these to identify important issues for future agricultural research. Using a scenario development method known as morphological analysis, scenarios were constructed that took economic, political, technical, and environmental factors into account. With the scenarios as a starting point future challenges were discussed and research issues and questions were identified in an interactive process with stakeholders and researchers. Based on the outcome of this process, six socioeconomic and biophysical overarching challenges for future agricultural were formulated and related research issues identified. The outcome was compared with research priorities generated in five other research programs. In comparison, our research questions focus more on societal values and the role of consumers in influencing agricultural production, as well as on policy formulation and resolving conflicting goals, areas that are presently under-represented in agricultural research. The partly new and more interdisciplinary research priorities identified in Future Agriculture compared to other programs analyzed are likely a result of the methodological approach used, combining scenarios and interaction between stakeholders and researchers.     

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.