Sperm competition affects sex allocation but not sperm morphology in a flatworm

Sperm competition has been shown to be an important evolutionary agent affecting the behaviour, physiology, and morphology of both males and females. One morphological trait that is particularly likely to be affected by sperm competition is sperm size because it is thought to influence the competitiveness of sperm by determining sperm longevity, motility, and/or their ability to displace competing sperm. Most comparative studies across taxa have found a positive relationship between the level of sperm competition and sperm length, but very few studies have tested for a phenotypically plastic adjustment of sperm morphology in response to sperm competition. In this study, we experimentally tested for an effect of sperm competition on phenotypic plasticity in sperm morphology in an obligately outcrossing simultaneous hermaphrodite, the free-living flatworm Macrostomum lignano, by either raising worms in monogamous pairs (no sperm competition) or in promiscuous groups (intense sperm competition). Worms in groups produced larger testes and smaller ovaries as predicted by sex allocation theory and as previously documented in this species. However, we found no evidence for an effect of group size on sperm morphology, measured as total sperm length, sperm body length, and the length of two different sperm appendages. We conclude that M. lignano may either be incapable of adjusting the sperm morphology in a phenotypically plastic way and/or that there might be no benefit of phenotypic plasticity in sperm traits in this species.     

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.     

Distribution,fate and formation of non-extractable residues of a nonylphenol isomer in soil with special emphasis on soil derived organo-clay complexes

Anthropogenic contaminants like nonylphenols (NP) are added to soil, for instance if sewage-sludge is used as fertilizer in agriculture. A commercial mixture of NP consists of more than 20 isomers. For our study, we used one of the predominate isomers of NP mixtures, 4-(3,5-dimethylhept-3-yl)phenol, as a representative compound. The aim was to investigate the fate and distribution of the isomer within soil and soil derived organo-clay complexes. Therefore, ¹⁴C- and ¹³C-labeled NP was added to soil samples and incubated up to 180 days. Mineralization was measured and soil samples were fractionated into sand, silt and clay; the clay fraction was further separated in humic acids, fulvic acids and humin. The organo-clay complexes pre-incubated for 90 or 180 days were re-incubated with fresh soil for 180 days, to study the potential of re-mobilization of incorporated residues. The predominate incorporation sites of the nonylphenol isomer in soil were the organo-clay complexes. After 180 days of incubation, 22 % of the applied ¹⁴C was mineralized. The bioavailable, water extractable portion was low (9 % of applied ¹⁴C) and remained constant during the entire incubation period, which could be explained by an incorporation/release equilibrium. Separation of organo-clay complexes, after extraction with solvents to release weakly incorporated, bioaccessible portions, showed that non-extractable residues (NER) were preferentially located in the humic acid fraction, which was regarded as an effect of the chemical composition of this fraction. Generally, 27 % of applied ¹⁴C was incorporated into organo-clay complexes as NER, whereas 9 % of applied ¹⁴C was bioaccessible after 180 days of incubation. The re-mobilization experiments showed on the one hand, a decrease of the bioavailability of the nonylphenol residues due to stronger incorporation, when the pre-incubation period was increased from 90 to 180 days. On the other hand, a shift of these residues from the clay fraction to other soil fractions was observed, implying a dynamic behavior of incorporated residues, which may result in bioaccessibility of the NER of nonylphenol.     

Educating the next generation of atmospheric scientists within a European Network of Excellence

In order to promote the next generation of atmospheric scientists, the task Training and Education (T&E) in ACCENT, the European Network of Excellence in Atmospheric Composition Change (www.accent-network.org) has developed and implemented an Integrated Learning Environment (ILE). For school teachers and their students, the Internet-based “Global Change Magazine” provides up-to-date and freely accessible scientific material in English and five other languages. Additionally, T&E has produced online teaching material for early-career scientists. These e-learning modules are now being used in University Master's courses across Europe. T&E also organised training events for early-career scientists, combining scientific content with development in transferable skills, to focus on interdisciplinary collaboration, interaction with senior scientists, communication with stakeholders, and dissemination to the general public. Evaluation based on participant feedback evidences the effectiveness of these events, e.g., in terms of motivation to remain in the field. Methodologies and materials from T&E are being published in a Handbook on Best Practice, intended for both educators and scientists around the globe who are involved in education in the field of air quality and climate change science.     

A correlation between the fate and non-extractable residue formation of 14C-metalaxyl and enzymatic activities in soil

Extracellular, oxidative soil enzymes like monophenol oxidases and peroxidases play an important role in transformation of xenobiotics and the formation of organic matter in soil. Additionally, these enzymes may be involved in the formation of non-extractable residues (NERs) of xenobiotics during humification processes. To examine this correlation, the fate of the fungicide ¹⁴C metalaxyl in soil samples from Ultuna (Sweden) was studied. Using different soil sterilization techniques, it was possible to differentiate between free, immobilized, and abiotic (“pseudoenzyme”-like) oxidative activities. A correlation between the formation of metalaxyl NER and soil organic matter content, biotic activities, as well as extracellular phenoloxidase and peroxidase activities in the bulk soil and its particle size fractions was determined. Extracellular soil-bound enzymes were involved in NER formation (up to 8% of applied radioactivity after 92 days) of the fungicide independently from the presence of living microbes and different distributions of the NER in the soil humic subfractions.     

Quantifying the effects of trampling and habitat edges on forest understory vegetation – A field experiment

We investigated the effects of human trampling on boreal forest understory vegetation on, and off paths from suburban forest edges towards the interiors and on the likelihood of trampling-aided dispersal into the forests for three years by carrying out a trampling experiment. We showed that the vegetation was highly sensitive to trampling. Even low levels of trampling considerably decreased covers of the most abundant species on the paths. Cover decreased between 10 and 30% on paths which had been trampled 35 times, and at least by 50% on those trampled 70–270 times. On-path vegetation cover decreased similarly at forest edges and in the interiors. However, some open habitat plant species that occurred outside the forest patches and at forest edges dispersed into the forests, possibly through the action of trampling. A higher cover percentage of an open habitat species at the forest edge line increased its probability to disperse into the forest interior. The vegetation community on, next to, and away from lightly trampled paths remained the same throughout the trampling experiment. For heavily trampled paths, the community changed drastically on the paths, but stayed relatively similar next to and away from the paths. As boreal vegetation is highly sensitive to the effects of trampling, overall ease of access throughout the forest floor should be restricted to avoid the excessive creation of spontaneous paths. To minimize the effects of trampling, recreational use could be guided to the maintained path network in heavily used areas.     

Measures of the EU Agri-Environmental Protection Scheme (GAEPS) and their impacts on the visual acceptability of Finnish agricultural landscapes

As a member of the European Union, Finland has committed itself to creating an environmental policy for agriculture. The aims of this study were to evaluate visual impacts of the General Agri-Environmental Protection Scheme (GAEPS) and Supplementary Protection Scheme (SPS) and general attitudes towards some activities in those policies and furthermore to examine the suitability of the method of Alho et al. (2001) for the scenic beauty assessment. The study areas consisted of three original, untreated, and 15 modified rural landscapes representing a variety of different activities. The scenic beauty of the landscapes was evaluated through pairwise comparisons of the responses of 68 people. Furthermore, attitudes towards environmental values, water protection, buffer strips and subsidies to agriculture were obtained. The respondents found the maintained buffer strips more pleasing than unmaintained strips and considered that the quality of watercourses was increased by buffer strips along them. A suitable width for the buffer strip along main ditches, brooks and waterways was regarded, on average, to be wider than the current recommendations. Although the opinions of farmers were basically in line with the existing recommendations, farmers' opininons on the second and third most important effects of buffer strips, an increase in weeds and a decrease in cultivated land, clearly differed from those of the other respondents. Afforestation, lack of building maintenance and abandoned fields were considered to be the most important factors impacting rural landscapes. This study indicates that the Finnish Agri-Environmental Protection Schemes have had positive impacts on the visual quality of landscapes. Attitudes towards other impacts are contradictory. This study also showed the improvement of the Alho et al. (2001) method in these kinds of studies relative to other methods of pairwise comparisons.     

Assessment of sampling and chemical analysis of source-separated organic household waste

The quality of the waste sampling procedure and chemical analysis was evaluated in a research program on characterization of organic waste obtained after disc screening of source-separated organic household waste. The sampling procedures focused on a truckload of waste and involved several steps of subsampling including shredding, mixing, blending, high-speed-blending, drying and milling prior to analysis of the organic waste with respect to ash content, crude fibers, crude fat, crude protein, sugar, starch, enzyme-digestible organic matter, P, N, C, H, S and calorific value. The statistical evaluation of the procedures involved 10 samples of the same truckload of waste obtained by splitting the sample at each level in the procedure according to a staggered, incomplete nested statistical design. Furthermore, one sample was analysed six times over a period of approximately one year. The statistical evaluation showed that no single step in the sampling procedure contributed with excessive variance and that the variance caused by the sampling procedure was approximately the same as the variance in the chemical analysis observed over a year. The variance varied with the analytical parameter but for most parameters the uncertainty was satisfactorily low (of the order of 3-10% expressed as the relative standard deviation, which is considered to be satisfactory for waste characterization).     

Exposure to methylhexahydrophthalic anhydride (MHHPA) in two workplaces of the electric industry

Methylhexahydrophthalic anhydride (MHHPA) is a hardener for hot-cured epoxy resins employed as insulators in the electric industry. MHHPA has only been measured as an ingredient with other alicyclic anhydrides, albeit there are also large processes which use only MHHPA. We collected MHHPA vapour in a set of devices: Teflon filter, glass spiral, TenaxTA tube connected consecutively together. Elution was performed with a solvent mixture of methyl-tert-butyl ether (70%), acetonitrile (30%), and acetic anhydride (0.5%). By capillary GC-ECD, the regression was linear (0.9994) in the practical low concentration range of 0.04-1 microg ml(-1) being equal to 0.001-0.035 mg m(-3) in 30 l of air. The exposure was measured in two factories manufacturing electric appliances. The assembled objects were first impregnated with a liquid epoxy/hardener mixture, and then the resin hardened at elevated temperature. In condenser manufacturing, the operators' 8 h exposure ranged from 0.068 to 0.118 mg m(-3), and the short-term exposure was during operation at ovens mean 1.90 mg m(-3). The impregnation of coiled resistors and transfer of them to ovens caused the worst exposures, short-term mean 3.846 mg m(-3) and long-term mean 2.191 mg m(-3). During the 'baking', the ovens were closed and evacuated, but when the hot objects were moved out of the ovens, they continued during chilling to emit MHHPA, mean 0.366 mg m(-3). In the adjacent areas, assembling, control rooms, offices, the exposure was still significant, 0.017-0.043 mg m(3), due to leaks from the high exposure areas. Mechanical general ventilation and local exhausts were functioning. Respirators were available for short supervising of the hot equipment.